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In this paper the planar orbit and attitude dynamics of an uncontrolled spacecraft is studied, taking on-board a deorbiting device. Solar and drag sails with the same shape are considered and separately studied. In both cases, these devices are assumed to have a simplified pyramidal shape that endows the spacecraft with helio and drag stable properties. The translational dynamics is assumed to be planar and hence the rotational dynamics occurs only around one of the principal axes of the spacecraft. Stable or slowly-varying attitudes are studied, subject to disturbances due to the Earth oblateness effect and gravity gradient torques, and either solar radiation pressure or atmospheric drag torque and acceleration. The results are analysed with respect to the aperture of the sail and the center of mass - center of pressure offset. | In the early to mid-2000s, NASA made substantial progress in the development of solar sail propulsion systems. Solar sail propulsion uses the solar radiation pressure exerted by the momentum transfer of reflected photons to generate a net force on a spacecraft. To date, solar sail propulsion systems were designed for large robotic spacecraft. Recently, however, NASA has been investigating the application of solar sails for small satellite propulsion. The NanoSail-D is a subscale solar sail system designed for possible small spacecraft applications. The NanoSail-D mission flew on board the ill-fated Falcon Rocket launched August 2, 2008, and due to the failure of that rocket, never achieved orbit. The NanoSail-D flight spare is ready for flight and a suitable launch arrangement is being actively pursued. This paper will present an introduction solar sail propulsion systems and an overview of the NanoSail-D spacecraft. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,500 |
A fuse inspection device having receiving terminals which are arranged in a longitudinal direction of a fuse box body and with which a plurality of band fuses are held in fit engagement. Windows are provided in side walls of accommodating chambers for the respective receiving terminals, and a slide knob slides along the band fuses. A sensing terminal moves together with the slide knob and has one end electrically connected with the receiving terminals through the window and has the other end brought into contact with a common conductive member. Electric conduction states of the band fuses are successively sensed by electrically connecting the sensing terminal and the receiving terminals through the movement of the slide knob. A plurality of connecting terminals each of which has one end held in contact with the corresponding receiving terminal through the window are arranged in ascendible fashion in the fuse box body and in a moving direction of the slide knob so that when one end of the sensing terminal has come into contact with any of the connecting terminals, the contact pressure between the other end of the sensing terminal and the conductive member rises, thereby to reliably sense the conduction state of the fuse. | Relatively simple methods for writer identification are presented in this work. The problems related to image acquisition, image preprocessing, feature selection and extraction as well as clustering and identification are analyzed. A couple of features is proposed towards a better discrimination result. The first feature is obtained using a morphological transformation of the word projection on the vertical axis, while the other from a local operation procedure using moments. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,501 |
We study spectral properties of a class of block 2 × 2 matrices that arise in the solution of saddle point problems. These matrices are obtained by a sign change in the second block equation of the symmetric saddle point linear system. We give conditions for having a (positive) real spectrum and for ensuring diagonalizability of the matrix. In particular, we show that these properties hold for the discrete Stokes operator, and we discuss the implications of our characterization for augmented Lagrangian formulations, for Krylov subspace solvers and for certain types of preconditioners. | The conjugate gradient method of Hestenes and Stiefel is an effective method for solving large, sparse Hermitian positive definite (hpd) systems of linear equations, $Ax = b$. Generalizations to non-hpd matrices have long been sought. The recent theory of Faber and Manteuffel gives necessary and sufficient conditions for the existence of a CG method. This paper uses these conditions to develop and organize such methods. It is shown that any CG method for $Ax = b$ is characterized by an hpd inner product matrix B and a left preconditioning matrix C. At each step the method minimizes the B-norm of the error over a Krylov subspace. This characterization is then used to classify known and new methods. Finally, it is shown how eigenvalue estimates may be obtained from the iteration parameters, generalizing the well-known connection between CG and Lanczos. Such estimates allow implementation of a stopping criterion based more nearly on the true error. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,502 |
This paper deals with the modeling of power transformers for calculation of switching transients based on mainly test report data. The paper is a follow-up of an IPST'07 paper and discusses the modeling and implementation of core saturation and losses in the Hybrid Transformer. A modified Frolich equation with knee-point adjustment and final slope handling is presented. The optimization process to fit the model to test report data is outlined and the modeling of topologically correct core loss is addressed. The inclusion of type 96 hysteretic inductors is presented. The final slope is a crucial parameter in inrush current calculations and requires design data. ransformers are critical components in the power system, but their representation in transient studies is often over- simplified. Several modeling approaches are documented in the literature (1) and this paper focuses on models with topologically correct cores. The Hybrid Transformer model (2)-(5) is an engineering transformer model based on limited input data. The modeling of the transformer is based on the magnetic circuit transformed to its electric dual (2), (3). The leakage and main fluxes are then separated into a core model for the main flux and an inverse inductance matrix for the leakage flux. The copper losses and coil capacitances are added at the terminals of the transformer. The resulting electrical circuit is shown in Fig. 1. Only standard EMTP elements are used. The model can be based on three sources of data: Design (specify geometry and material parameters of the core and windings), Test report, and Typical (typical values based on the voltage and power ratings). It handles 3-phase transformers with two or three windings. Autotransformers and all Wye and Delta couplings are supported. The model includes an inverse inductance matrix for the leakage description, optional frequency dependent winding resistance, capacitive coupling, and a topologically-correct core model | Summary form only given. A new topologically-correct hybrid transformer model is developed for low- and mid-frequency transient simulations. Power transformers have a conceptually simple design, but behaviors can be very complex. Selection of the most suitable representation for a given behavior depends on the type of transformer to be simulated, the frequency range, and other factors such as the internal design of the transformer and available parameters or design data. Here, a modular model suitable for frequencies up to 3-5 kHz is developed, utilizing a duality-based lumped-parameter saturable core, matrix descriptions of leakage and capacitive effects, and frequency-dependent coil resistance. Implementation and testing of this model was done for 15-kVA 208D-120Y 3-legged and 150 kVA 12, 470Y-208Y 5-legged transformers. The basis and development of the model is presented, along with a discussion of necessary parameters and the approaches for obtaining them. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,503 |
Recent advances in electrical sensing and flexible devices have demonstrated great potential in a wide range of applications including wearable devices for fitness and health care. Flexible plastic substrates, such as polyimide, or transparent conductive polyester are used to fabricate flexible devices that increase the comfort when they are worn by users or patients. However, one challenge that still limits the success of wearable devices is the limited lifetime especially in biomedical applications. Energy harvesting technology is one of the most promising approaches to address the short lifetime of wearable devices. However, harvesting energy for powering wearable devices is more challenging due to strict constraints in terms of size, weight and cost. In this work, we present the design of a wearable smart bracelet that uses thin-film small form factor flexible photovoltaic panels as energy source. The solar energy harvesting subsystem has been designed to maximize the energy conversion efficiency (up to 90%) to achieve a self-sustainable wireless wearable system. The full-system integration has been developed and assembled using polyamide film to realize a fully flexible smart bracelet for long term monitoring of patients or elderly people in healthcare applications. Preliminary in-field experiments show that a single flexible solar panel can harvest up to 16mW of power in outdoor and 0.21mW in indoor scenarios. We demonstrate that, the developed device, combining low power design and flexible energy harvesting, achieves perpetual work, acquiring one blood oxygenation measurement per minute and sending data via Bluetooth. | Energy harvesting has emerged as a promising technology for small electronic devices to extend the battery run time and thereby enabling an increased autonomous operation. However, frequent charge and discharge cycles cause aging effects in the battery, which results in a loss of capacity and life time.Power-neutral transient computing systems avoid energy buffers by powering the load by the harvester directly. Usually, the power outputs of energy harvesters rely on arbitrary and transient environmental excitations. The resulting power losses are handled by checkpointing, where the volatile system state is backed up using non-volatile memories. The timely detection of upcoming power losses is essential for a reliable checkpointing process. Early detections allow a proactive power loss handling, which is important to ensure the finalization of atomic operations. However, common voltage threshold-based methods only allow short-term power loss detections since they do not adapt to the dynamics of the harvester.In this paper we propose a new methodology that allows an early power loss detection by exploiting physical characteristics of the harvester. The proposed approach points out new opportunities for transiently-powered devices, as it allows an adaptive and harvester-aware computing. We show how it facilitates a proactive scheduling that is used to ensure a successful finalization of atomic operations. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,504 |
In this paper, an ultra-wideband (UWB) bandpass filter (BPF) composing of a multi-mode resonances SIR is proposed. The SIR provides three resonances to form the passband response. However, the acquired bandwidth (BW) is insufficient and it is remedied by an open and a short-circuit stub, attaching to the SIR in the middle. The added open and short stubs with appropriate length furnish the SIR with two extra resonances, below and above its original ones. The sandwich-coupled-lines structure is implemented in the feed structure to provide the tight coupling needed by the UWB BPF. This feed structure alleviates the manufacturing tolerance caused by a small gap used in a conventional coupled-lines design. To further enhance the coupling strength of the sandwich-coupled lines, a slot is embedded in the ground plan beneath the feed. Experiments are conducted to verify the UWB BPF and agreements between the simulation and the measurements are observed. | This paper demonstrates a general concept and different types of filters and a diplexer realized in suspended stripline using quasi-lumped elements. Very small low-pass, bandpass, and high-pass filters with typically low loss are designed, fabricated, and tested; even transmission zeroes can easily be included into the design by additional coupling structures. Finally, a low-pass and high-pass filter are combined to form a diplexer of very small size. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,505 |
Nine digital halftoning procedures, including two algorithms proposed by us, are compared to find out which one is best suited for binarization of continuous-tone pupil filters. The procedures we deal with include iterative, error diffusion, error convergence and one-pixel algorithms. In our numerical experiment the performance of binary filters is examined in terms of two parameters: the resemblance of their amplitude impulse response (AIR) to the AIR of the original continuous filter, as well as their light efficiency. The examination is carried on for super-resolving, apodizing and sine-wave pupil filters. The results are to a certain extent object dependent, nevertheless some general conclusions are presented. | In this paper we show new ways to improve the performance of ground-based coronagraphy. We introduce adaptive coronagraphic masks whose profile is a binary version of the instantaneous atmospherically degraded star image. We also propose the hyper-Gaussian profile masks obtained by averaging adaptive masks. In addition, adaptive Lyot stops and hyper-Gaussian Lyot stops are analyzed. Computer simulations show that all these masks outperform the circular hard-edged mask and that a proper mask and stop combination significantly reduces the angular separation at which a faint companion can be detected. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,506 |
892,041. Carrying liquefied gas cargo. CORY & SON Ltd., Wm. March 31, 1958 [April 5. 1957], No. 11124/57. Class 113. [Also in Group XXVIII] A tanker for the bulk transport in the liquid state at low temperature of methane (or like ordinarily-gaseous substance) has liquefaction plant and circulating connections between the cargo tank or tanks and the plant whereby the gaseous methane boiling off in the tanks can be withdrawn, reliquefied and returned to the tanks. The ship is of turret construction with heavily insulated main tanks 18-23 extending substantially the full width of the ship and smaller tanks 33 which can be used to top up the main tanks if the liquefaction plant is unable to do so the cargo in the main tanks is kept topped up to a level in the narrow neck 27 of each tank, which neck is surmounted by a pump motor housing 32. These tanks extend up through the main deck 24 and except for tank 20 their necks 27 reach up through the turret deck 25. Main and secondary liquefaction plants are disposed at locations 76 and 77 respectively. In an emergency methane gas may be vented to atmosphere through six pairs of mast vents each having an anti-flash gauge at its upper end. Excess methane gas may be burnt off at flares on top of the masts 64 and 65. Specifications 892,042, 892,043, 892,044, 892,045, 892,046 and 892,047 are referred to. | The authors gratefully acknowledge the support of the Deep Carbon Observatory and DECADE (part of the Reservoirs and Fluxes community), the Natural Environment Research Council (NERC) Centre for the Observation and Modelling of Earthquakes, Volcanoes and Tectonics (CO MET), the British Geological Survey and the University of Cambridge Isaac Newton Trust. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,507 |
Absorption, and reflexion spectra of GaSe near the fundamental gap are interpreted in terms of pseudopotential band calculations. Selection rules for the direct optical valence-to-conduction band transitions are derived. Valence band mixing induced by spin-orbit coupling is invoked to explain the low observed probability for transitions in light polarized perpendicular to the crystal c-axis. The spectra of the excitons associated with the direct gap are discussed in the ellipsoidal effectivemass approximation. Corrective terms are added to account for the observed exchange splitting of the exciton ground state. Field-free spectra as well as spectra modified by the presence of magnetic fields parallel and perpendicular to c are considered. The magneto-Stark effect which gives rise to a mixing of the 2s and2py states and thus renders the2py state visible affords determination of the anisotropy parameter. The value of this parameter as well as those of the components parallel and perpendicular to c of the reduced effective masses show that the electronic states in GaSe are nearly isotropic. This is in good agreement with the results of the pseudopotential band calculations which clearly demonstrate the three-dimensional character of valence and conduction bands. | We report nearly complete preservation of “spin memory” between optical absorption and photoluminescence under excitation >0.2 eV above the band gap in nanometer GaSe slabs. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,508 |
Properties of dc vacuum arcs between copper electrodes are studied in both a vacuum interrupter and a metal walled arc chamber. Maximum ion currents of ∼8 to 20 percent of the arc current (100 to 3000 A) are drawn from the diffuse arc plasma when the bounding metal wall or shield is biased negative. This maximum ion current is a fundamental arc property independent of wall diameter, anode diameter, and electrode spacing. The geometric dependence of the wall ion current, together with observations of isotropic vapor and ion emission from the cathode, indicates that the cathode regions adjacent to the cathode spots are the predominant sources of ionization for the plasma. Assuming single ionization, 55 percent of the vapor leaving these regions is ionized. Starvation phenomena in the anode region remote from the cathode spots lead to anode voltage drop and anode spot formation. Post arc currents reveal a mean ion speed during arcing of ≈8×105cm/s. This mean speed may be acquired in the cathode region by acceleration from a potential maximum. | The shield current distribution in a vacuum arc between CuCr40 contacts was studied by means of three cylindrical shields arrangement. It was found that the total shield current is affected by the arc mode. For a high-voltage oscillation sequence a significant effect on shield current distribution has an anode plasma jet. Then a great increase of the shield current is observed and the ratio of shield current to arc current was even more than 20%. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,509 |
The model output of rainfall total prediction has to be validated before being applied to the operational use. After understanding the accuracy of this rainfall total prediction output, one has to make decision whether applying it in the field or not. This depends upon the value of accuracy as well. Validation technique for simple operational use can be made by applying Pearson’s correlation coefficient (r), Root Mean Square Error (RMSE), and spatial rainfall defferentiation values (ΔRR). The Wavelet Transformation Technique (WTT) for providing rainfall total prediction output of rainy and transition seasons 2003 had been applied to the domain of interest Indramayu, Sumedang, and Majalengka districts. Results show that during January 2003 (rainy season respectively) r = 0.65 with RMSE = 296 mm and 75.39% spatial disagreement area; but within April 2003 (transition season respectively) r = 0.49 with RMSE = 152 mm and 43.55% spatial disagreement area. Topography condition has play a role to the rainfall deferenciation values, especially for Lee-ward location. This is described by higher differentiation values of rainfall total prediction after reaching the top of elevation above mean sea level. | A hot melt composition for forming flowed-in closure liners or gaskets having a viscosity and resulting flow properties suitable for use in high speed, liner forming operations. The composition comprises between 20 and 55 percent of a thermoplastic elastomer chosen from the group consisting of block copolymers of the type having the general formula A-B-A or of the type having a plurality of chains of the general formula B-A radiating from a central hub. A is a thermoplastic segment, preferably polystyrene, and B is an elastomeric segment, preferably polybutadiene, polyisoprene, or polyethylene-butylene. The other ingredients in the composition may be extenders, antioxidants, fillers, pigments, lubricants, etc. as desired. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,510 |
Timing jitter as a key performance of single-photon avalanche diode (SPAD) detectors plays a significant role in determining the fast temporal response behavior of the SPAD device. Nevertheless, few analytic models are developed to directly calculate the characteristic of timing jitter for its modeling difficulty. In this paper, we propose a simple analytic modeling method, which can predict the temporal response of SPADs, without using time-consuming Monte Carlo simulation. Model investigation incorporates avalanche current, avalanche buildup time, and jitter tail under different conditions. Furthermore, the key model parameters provided by Geiger mode technology computer-aided design simulation allow an accurate prediction on timing jitter. Analytical results indicate that for an SPAD device structure with a shallow P+/N-well junction in a 0.18- $\mu \text{m}$ CMOS technology, the Gaussian peak response with about 110-ps full-width at half-maximum and the exponential jitter tail are in good agreement with the measured data, validating the accuracy, and feasibility of this modeling method. | The effects of dead space (the minimum distance trav- elled by a carrier before acquiring enough energy to impact ionize) on the current impulse response and bandwidth of an avalanche multiplication process are obtained from a numerical model that maintains a constant carrier velocity but allows for a random dis- tribution of impact ionization path lengths. The results show that the main mechanism responsible for the increase in response time with dead space is the increase in the number of carrier groups, which qualitatively describes the length of multiplication chains. When the dead space is negligible, the bandwidth follows the be- havior predicted by Emmons but decreases as dead space increases. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,511 |
The finding that threat boosts the public's preferences for authoritarian policies has been well established in the research literature. Why this shift occurs remains open as the extant literature reports contradictory findings regarding the interaction of dispositions, such as conservatism and authoritarianism, with threat. One line of research argues that threat increases authoritarian preferences among those who are more prone to authoritarianism. Another argues that it is those with a nonauthoritarian ideology who switch in response to threat. By using a two-wave panel study of the French population taken before and after the January 2015 twin attacks in Paris, we find that both trends occur simultaneously. Our results show that the factors that drive the impact of ideological dispositions on support for authoritarian policies are emotional reactions. On the one hand, anxiety led left-wing respondents to move towards adopting authoritarian policy preferences following the attacks, yet produced no such change among right-wing respondents. On the other hand, anger did not turn left-wing voters more authoritarian but strengthened authoritarian policy preferences among right-wing respondents. | Terrorist attacks negatively affect support for immigration policy, and this has been linked to the extensive media coverage of terrorism. Yet, this coverage may also have a moderating effe... | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,512 |
Experiments based on Froude scaling law were conducted in a 1/10 reduced-scale model tunnel to investigate the effect of slope on critical velocity in tunnel with longitudinal ventilation under fire. Methanol pool fire was used as the fire source. Smoke movement in the model tunnel with different combination of tunnel slope (−3%, −1.8%, −1%, 0%, 1%, 1.8% and 3%) and longitudinal ventilation velocity was studied. The longitudinal distribution of temperature and velocity were measured. Critical longitudinal ventilation velocity for arresting smoke back flowing in the model tunnel was investigated. Critical velocity in horizontal tunnel obtained in this study was used to compare with that of previous studies. The experimental results agreed well with the model proposed by Wu and Bakar. Correlation between the critical velocity and the slope of the tunnel is proposed based on the experiment results. As the tunnel slope increases from downhill to uphill, critical velocity decreases nearly at a rate independent of the heat release rate of the fire source. The correlation proposed in this studied agrees well with the equation adopted in the Subway Environment Simulation Computer Program (SES). However, it has some discrepancy with the expressions proposed by Atkinson and Ko et al. based on their experimental results. The cause of the discrepancy is attributed to different configuration of the experiments. | In this paper, the influence of slope on the spreading characteristics of fire smoke in the semitransverse ventilated tunnels was studied by using the FDS simulation. Through simulation experiments, the reasonable smoke exhaust strategies for preventing fire smoke from spreading in the sloping tunnel were obtained. Simulation results showed that: under 30MW fire power, the two-way balanced smoke exhaust strategy had good effect for the semi-transverse ventilated horizontal tunnel. However, in the sloping tunnel, due to the high stack effect, more smoke flowed to the upgrade direction. When the slope angle was greater than 1.5%, the smoke in the downgrade direction was controlled within the smoke vent opening range due to the effect of fire wind pressure. At this time, in order to effectively exhaust the smoke and reduce the energy consumption of the smoke exhaust fan, the unilateral smoke exhaust strategy in the upgrade direction was adopted. When the tunnel slope was less than 2%, appropriately increasing the smoke exhaust amount could strengthen the smoke exhaust effect and prevent the smoke from spreading to the exit of the tunnel. When the slope was greater than 3%, due to the high stack effect, the smoke in the tunnel spread rapidly to the exit. Then adding the vertical ventilation in the upgrade direction and preventing the smoke from returning could better limit the smoke spreading scope. Keywords-Slope: Smoke Exhaust Strategy; Tunnel Fire; Smoke Spread; Semi-transerse Ventilation | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,513 |
: Initiation by the U.S. Army Tank-Automotive Command(TACOM) of the Advanced Integrated Propulsion System (AIPS) prompted the development of referee fuels that would (1) indicate to prospective engine/component developers the anticipated quality of fuels available when AIPS is fielded as part of the next main battle tank, and (2) a means for TACOM to ensure that new engines and components would be able to fully demonstrate a 'multifuel capability.' This study resulted in the development of two referee fuels: Type I, A high-volatility, Low-viscosity fuel; and Type II, A low-volatility, high viscosity fuel, both having low cetane numbers. Future multifuel engine design and development work will use these referee fuels to ensure operation on a broad range of fuels that may become available. | It is the purpose of this paper to report the relative miles of transportation that can be obtained from a barrel of crude oil by using different types of engines and fuels. The options that have been studied are: 1. Use of leaded gasoline in an internal combustion engine. 2. Use of unleaded gasoline. 3. Maximum use of diesel engines. 4. Maximum use of the direct injection stratified charged engine. 5. Maximum use of gas turbine engines. It will be shown that the engine-fuel option chosen will have a large effect on the crude oil imports required which, in turn, will have a substantial impact on the United States domestic economy and balance of payments. /GMRL/ | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,514 |
We are concerned with the estimation of the frequency of a complex sinusoid that has been corrupted by complex-valued multiplicative and additive noise. This problem is important in many applications including array processing in the case of spatially distributed sources and synchronization in the context of time-selective channels. The multiplicative noise smears the spectral line due to the sinusoid. This smearing, which is often called Doppler spreading, may significantly degrade the estimation accuracy. The goal of this paper is to analytically assess this degradation. The finite-sample Cramer-Rao bounds (CRBs) are derived, and closed-form expressions are given for the large-sample CRB. The latter gives insights into the effective coherent and noncoherent SNRs for frequency estimation. We then analyze the accuracy of frequency estimators that are based on the angles of the sample covariances. Simulations results are presented to illustrate the theoretical results. | In this paper, we investigate the problem of carrier frequency offset (CFO) estimation for orthogonal frequency division multiplexing (OFDM) system over doubly-selective channels. Representing the doubly-selective channels with basis expansion, the signal model is reformulated and one CFO estimator is derived. Furthermore, the Cramer-Rao bound (CRB) for the estimation problem is derived in closed form. The effectiveness of the proposed scheme is verified by simulations. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,515 |
Theoretical prediction of forming limit strain of sheet metal is developed in the framework of the three-dimensional general bifurcation theory. The onset of the three-dimensional discontinuous velocity field in the biaxially stretched uniform sheet is predicted. Three fundamental mode vectors, i.e. shear horizontal, shear vertical and normal modes are introduced and it is demonstrated that any bifurcation mode is represented by the linear combination of them. The onset of the bifurcation is numerically analyzed in terms of the modes by the use of the linear comparison solid originally introduced by Hill in 1959. In this study, a linear constitutive relation is adopted for the linear comparison solid, which is developed based on the constitutive theory proposed by Goya and Ito and is capable of incorporating the directional dependence of the plastic strain rate on the stress rate. The numerical results show that forming limit strains predicted by the three-dimensional mode theory is much higher in general than that given by Storen and Rice in 1975. Then, it is revealed from the three-dimensional mode analysis that the bifurcation mode that arises can be changed from one type to another according to the sign of stress ratio. It is also shown that the strain limit predicted by the three-dimensional mode analysis gives upper limit lines for the bifurcation lines proposed in the past for any linear strain-path directions. | Sheet metal forming processes generally involve large deformations together with complex loading sequences. In order to improve numerical simulation predictions of sheet part forming, physically-based constitutive models are often required. The main objective of this paper is to analyze the strain localization phenomenon during the plastic deformation of sheet metals in the context of such advanced constitutive models. Most often, an accurate prediction of localization requires damage to be considered in the finite element simulation. For this purpose, an advanced, anisotropic elastic–plastic model, formulated within the large strain framework and taking strain-path changes into account, has been coupled with an isotropic damage model. This coupling is carried out within the framework of continuum damage mechanics. In order to detect the strain localization during sheet metal forming, Rice’s localization criterion has been considered, thus predicting the limit strains at the occurrence of shear bands as well as their orientation. The coupled elastic–plastic-damage model has been implemented in Abaqus/implicit. The application of the model to the prediction of Forming Limit Diagrams (FLDs) provided results that are consistent with the literature and emphasized the impact of the hardening model on the strain-path dependency of the FLD. The fully three-dimensional formulation adopted in the numerical development allowed for some new results – e.g. the out-of-plane orientation of the normal to the localization band, as well as more realistic values for its in-plane orientation. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,516 |
The current escalation in user demand for web contents, particularly Video on Demand (VoD), is causing a continuing increase in both the types of web traffic and the volumes of data transmitted. The greater demand arises from the new means of communication employed by individuals and companies, as well as the development of readily usable applications distributed by ‘app stores’. In this paper, we suggest that the stakeholders of a VoD framework, the Content Providers (CPs) and the Internet Service Providers (telcos/ISPs), should guarantee a solid Quality of Experience (QoE) to the end user through two potential investments: either in ultra-broadband (UBB) or in the technologies for the acceleration of web content, known as the Content Delivery Network (CDN) and Transparent Internet Caching (TIC). The aim of the paper is to analyse these investments in terms of providers' profits. The base hypothesis is that the investments are subsidized by the CPs, which, in recent years, have indeed been directing a la... | This paper investigates how broadband penetration affects economic growth. A macroeconomic production function with a micro-model for broadband investment is used to estimate the impact of broadband infrastructure and growth. The results indicate a significant causal positive link especially when a critical mass of infrastructure is present. The scope of this research is 22 OECD countries based on data collected for the period 2002-2007. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,517 |
The simplified Lennard-Jones (LJ) potential minimization problem is minimize f(x)=4\sum_{i=1}^N \sum_{j=1,j<i}^N (\tau_{ij}^{-6} -\tau_{ij}^{-3}) subject to x\in \mathbb{R}^n, where $\tau_{ij}=(x_{3i-2}-x_{3j-2})^2 +(x_{3i-1}-x_{3j-1})^2+(x_{3i} -x_{3j})^2$, $(x_{3i-2},x_{3i-1},x_{3i})$ is the coordinates of atom $i$ in $\mathbb{R}^3$, $i,j=1,2,...,N(\geq 2 \quad \text{integer})$, $n=3N$ and $N$ is the whole number of atoms. The nonconvexity of the objective function and the huge number of local minima, which is growing exponentially with $N$, interest many mathematical optimization experts. The global minimizer should be just at the point of the bottom of the LJ potential well. Based on this point, this paper tackles this problem illuminated by amyloid fibril molecular model building. The 3nhc.pdb, 3nve.pdb, 3nvf.pdb, 3nvg.pdb and 3nvh.pdb of PDB bank are used for the successful molecular modeling. | In this paper we consider global optimization algorithms based on multiple local searches for the Molecular Distance Geometry Problem (MDGP). Three distinct approaches (Multistart, Monotonic Basin Hopping, Population Basin Hopping) are presented and for each of them a computational analysis is performed. The results are also compared with those of two other approaches in the literature, the DGSOL approach (More, Wu in J. Glob. Optim. 15:219---234, 1999) and a SDP based approach (Biswas et al. in An SDP based approach for anchor-free 3D graph realization, Technical Report, Operations Research, Stanford University, 2005). | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,518 |
Neonymium doped bismuth borate glasses with composition 50Bi2O3 : (50-x)B2O3: xNd2O3 (where x = 0.5, 1.0, 1.5, 2.0 and 2.5 mol%) have been prepared by melt quenching technique. The optical and upconversion luminescence properties of glasses were investigated. The nine absorption peaks were observed, correspond with Nd3+ energy level in glass. The optical band gap decreased with increasing Nd2O3 concentration due to the increase of non-bridging oxygen (NBOs) in glass matrix. The upconversion luminescence emission spectra shows peak at 393 nm, assign to 4D3/24I11/2 transition. | Vibrational spectroscopy is one of the most familiar tools for understanding the molecular structure and molecular bonding. In the present investigation, glasses of the following chemical compositions 35ZnO–30Na 2 O–(35− x )B 2 O 3 – x Nd 2 O 3 where x ranges from 0, 1 and 2 were prepared. The local structures of the glasses were investigated through Fourier transform infrared spectroscopy. The glass transition studies were carried out by differential scanning calorimetry. Absorption and fluorescence studies for 1 mol% Nd 3+ -doped glass are also analysed. Judd–Ofelt parameters for f–f transition were derived from the integrated absorption spectra and by using this J–O parameters the spontaneous emission probability and stimulated emission cross-section was calculated for the 4 F 3/2 → 4 I 11/2 transition. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,519 |
We show that tri-layer structures combining epsilon-negative and magneto-optical material layers can exhibit unidirectional resonant photon tunneling phenomena that can discriminate between circularly polarized (CP) waves of given handedness impinging from opposite directions, or between CP waves with different handedness impinging from the same direction. This physical principle, which can also be interpreted in terms of a Fabry-Perot-type resonance, may be utilized to design compact optical isolators for CP waves. Within this framework, we derive simple analytical conditions and design formulae, and quantitatively assess the isolation performance, also taking into account the unavoidable imperfections and nonidealities. | Asymmetric transmission (AT) holds significant applications in controlling polarization and propagation directions of electromagnetic waves. In this paper, tilted rectangular nanohole (TRNH) arrays in a square lattice are proposed to realize an AT effect. Numerical results show two AT modes in the transmission spectrum, and they are ascribed to the localized surface plasmon resonances around the two ends of TRNH and surface plasmon polaritons on the golden film. AT properties of the TRNH strongly depend on structural parameters, such as width, length, thickness, and tilted angle of TRNH. Results provide a novel mechanism for generating AT effect and offer potential plasmonic device applications, such as asymmetric wave splitters and optical isolators. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,520 |
Mesoporous organosilicas were synthesized by sol-gel co-condensation of tetraethoxysilane and appropriate alkoxysilanes in the presence of Pluronic P123 surfactant. Hexyl, dodecyl, and octadecyl alkyl chains have been incorporated into mesopores by such co-condensation. Obtained materials were characterized by X-ray diffraction, FTIR spectroscopy, nitrogen adsorption measurements and thermogravimetry. Two resulted materials have highly ordered SBA-15 structure (p6m symmetry), other two are less ordered. All the materials exhibit well-developed porous structure (surface areas 500 to 830m2/g, pore volumes 0.65–1.32 cm3/g) and a high content of organic pendant groups introduced during co-condensation. All materials are thermally stable to 180°C, after that thermal decomposition of alkyl pendant groups starts. | Mesoporous silicas were synthesized by condensation of tetraethoxysilane (TEOS) in the presence of Pluronic P123 as a structure-forming agent, and sucrose as an auxiliary agent, to investigate the effect of sucrose and aging temperature on the final properties, particularly structure-adsorption characteristics. Obtained materials have been characterized by XRD, nitrogen sorption measurements SEM-EDX, TEM, thermogravimetry, and FT-IR. The obtained materials have well-developed porous structure—values of the specific surface area (SBET) are in the range of 300–950 m2/g and the sizes of primary mesopores are in the range of 9–11 nm. It was established that SBET and ordering significantly decreases with an increasing content of sucrose in the initial mixture. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,521 |
In magnetic confinement Nuclear Fusion video cameras have become routine diagnostics, which can produce gigabytes of data per discharge. New tools and methods are required to manipulate the frames of these videos to obtain the required information. New algorithms have been developed, which implement pattern recognition methods to search the repositories of videos on the basis of their content and not on their address. Real time automatic analysis of videos has motivated the development of machine learning tools to classify objects in images. The identification and tracking of objects in the videos of Tokamak diagnostics requires the computation of image descriptors, which are insensitive to rotation, translation and rescaling. The Hu moments have proved to be quite effective in performing this image analysis task (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) | List of Algorithms. Preface. Possible Course Outlines. 1. Introduction. 2. The Image, Its Representations and Properties. 3. The Image, Its Mathematical and Physical Background. 4. Data Structures for Image Analysis. 5. Image Pre-Processing. 6. Segmentation I. 7. Segmentation II. 8. Shape Representation and Description. 9. Object Recognition. 10. Image Understanding. 11. 3d Geometry, Correspondence, 3d from Intensities. 12. Reconstruction from 3d. 13. Mathematical Morphology. 14. Image Data Compression. 15. Texture. 16. Motion Analysis. Index. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,522 |
Purpose – The purpose of this paper is to present and implement an algorithm to prioritize welding quality deterioration factors for improving welding personnel performance. A case study is carried out in a piping components fabrication process which supplies these components to oil and gas production and processing facilities on the Norwegian continental shelf (NCS).Design/methodology/approach – The quality deterioration factors' prioritization is carried out using statistical methods in conjunction with the data recorded in the welding inspection database (WIDB) of the case study company. Data cleaning and rearrangements were performed to reflect final objective. Based on the welding procedure specifications (WPSs) and quality imperfection groups classified in NS‐EN ISO 6520‐1, the analysis is performed to prioritize the welding quality deterioration factors.Findings – Based on the WPSs and quality imperfection groups classified in NS‐EN ISO 6520‐1, it is possible to prioritize the welding quality deter... | Construction is not manufacturing. However, manufacturing provides the elements from which buildings, bridges, highways, houses and factories are constructed. Many of these elements are made-to-stock, but some key elements are made-to-order; e.g., HV AC ductwork, custom piping, pipe supports, precast concrete, electrical switchgear, reinforcing steel, structural steel and building envelope facades. These made-to-order products are produced by fabrication shops, which sit squarely at the intersection of manufacturing and construction. Application of lean concepts and techniques to fabrication shops promises substantial benefits to the construction industry they serve. Perhaps chief among these benefits is reducing the lead time required for placing orders in advance of needed delivery. Long lead times can extend project durations, promote premature design decision making or otherwise avoidable design redundancy, and cause excess inventories and double handling of materials. A "long" lead time is determined relative to the ability of the customer (the construction site) to accurately forecast future states of the building process on site, and thus the ability to determine when a component will be required for installation. Lead times that exceed a site's window of reliability increase the probability of untimely delivery. On time-driven projects, such lead times also increase the risk of premature design decisions and/or building slack into designed capacities and strengths. Switching perspectives, demand variability is arguably the biggest headache for fabricators. Late receipt of design information, frequent design changes and changes in installation timing and sequence disrupt production schedules and cause fabricators to risk the loss of capacity. In this paper, we explore the interplay between demand variability and fabrication lead times and present a plan to study and understand their interdependencies. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,523 |
This paper presents a design methodology which automates the generation of curves extracted from the point clouds that have been obtained by digitizing the physical objects. The methodology is described on a product belonging to the industry of consumables, respectively a footwear type product that has a complex shape with many curves. The final result is the automated generation of wrapping curves, surfaces and solids according to the characteristics of the customer's foot, and to the preferences for the chosen model, which leads to the development of customized products. | In this study we present a 3D garment design method for scanned human bodies. Firstly, a slicing method is proposed to reconstruct a symmetric body from a scanned human body to make it suitable for garment design. Secondly, a sketch modeling method is used to interactively create the garment surface based on the new body. Thirdly, seam lines are drawn on the garment surface, and then a flattening algorithm is employed to design 2D patterns. Finally, a seam line template is used to design the same style for different bodies. Experiments show that the resulted garment well fits the scanned body. Our method provides an efficient design tool for customizing garments in the fashion industry. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,524 |
A dynamic model of landing gear struts is introduced in a non-inertial coordinate system. Together with a six degrees of freedom model of aircraft ground handling, the model can be applied to investigate the landing gear shimmy and the directional stability of aircraft undergoing non-straight taxiing. Take the K8 aircraft as an example, motions of the strut under both the straight and non-straight taxiing are simulated as well as the directional adjusting procedure of the airframe. Results of the example are reasonable, indicating that the model may have some value in related research. | This study investigates an instability that was observed during high-speed taxi tests of an experimental flying-wing aircraft. In order to resolve the reason of instability and probable solution of it, the instability was reproduced in simulations. An analysis revealed the unique stability characteristics of this aircraft. This aircraft has a rigid connection between the nose wheel steering mechanism and an electric servo, which is different from aircraft with a conventional tricycle landing gear system. The analysis based on simulation results suggests that there are two reasons for the instability. The first reason is a reversal of the lateral velocity of the nose wheel. The second reason is that the moment about the center of gravity created by the lateral friction force from the nose wheel is larger than that from the lateral friction force from the main wheels. These problems were corrected by changing the ground pitch angle. Simulations show that reducing the ground pitch angle can eliminate the instability in high-speed taxi. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,525 |
The security dilemma, first coined by John Herz in 1950, has come to explain why states that do not seek to harm one another can still end up in competition and war. Its very essence is one of tragedy. The security dilemma has been expounded since by a number of authors, and in this article I examine one such development; Jack Snyder’s definition of the security dilemma, being applicable where one state requiresthe insecurity of another. I label this a state-induced security dilemma. I argue that in order for this to be an accurate expansion of the security dilemma, the essence of tragedy must be retained. I suggest that with some refinement Snyder’s definition does extend the application of the security dilemma and raises important questions regarding the dilemma’s mitigation and escape. I have used the relationship between China and Taiwan to elucidate the utility of the state-induced security dilemma. | The aim of the paper is to understand the specifics of the interaction of two models of regional economic integration co-existing in Eastern Europe: the post-Soviet integration and the cooperation with the EU. The paper claims that institutional competition between integration projects may generally improve the quality of international institutions; however, the post-Soviet integration model should be seriously re-designed for this purpose. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,526 |
Currently, the traditional search techniques can’t meet people’s demand. Along with constantly improving the precision and recall ratio of search engine, the demand of personalized service becomes particularly outstanding. Intelligent search system of network manufacturing resource is a focused search engine which orients to network manufacturing resource. Meanwhile, the system includes personalized service to improve the intelligent level of search. In this article, considering the characteristics of network manufacturing resource environment, the author studies the personalized service model of retrieval system based on manufacturing resource, designs the architecture of the system, and scrutinizes the key techniques and core algorithms of the system. Lastly, the article shows the prototype system of intelligent searching system based on manufacturing resource personalized service. | E-Hubs as new entrants with new business models pour into the business-to-business space; it's increasingly difficult to make sense of the landscape. Electronic hubs--Internet-based intermediaries that host electronic marketplaces and mediate transactions among businesses--are generating a lot of interest. This paper provides a blueprint of the E-Hubs arena. Conceptual specification of functional system, comprising the selection of core E-Hubs services and definition of basic hosting platform of the E-Hubs realization business development plan, Conceptual framework for Manufacturing Resource Management System designs based on E-hubs. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,527 |
The paper deals with tests of surface layer properties of copper alloy casts based on the example of MO59 alloy. The main purpose of the paper is presenting hardness distributions of the analysed samples and determining the optimal technological allowance. Based on the results of the hardness distributions tests recommended technological allowances on two planes were determined. Moreover, influence of cast wall thickness on durability properties of the tested casts was determined. | Safety and traffic flow of production facilities also depends upon the reliability of technical security equipment. Gearing in the transmission mechanisms must satisfy the conditions of strength calculation. This calculation consists of checking of the gear teeth on bend and contact. From the stress of gears is show that the basic requirements of the material are high hardness of works surfaces and bending strength. Steels best meet these conditions. Used steel with surface hardness up to 350 HBW, or heat treated steel with hardness of 500-650 HBW. The advantage of these materials is the high value of the contact pressure in the tough centre core of the tooth. As a final heat treatment are used surface hardening, cementation and hardening, nitridation and carbo-nitridation. Good properties of heat-treated steels are at the correct thickness of the heat-treated layer of the tooth. This paper considers the appropriate choice of parameters to obtain the desired level of safety of gears in a gearbox to drive the conveyor in the metallurgical industry under increased load. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,528 |
Texas Instruments has been developing a passive tag which removes some of the practical difficulties, meeting the optimum cost/performance trade off and performance requirements for two dedicated market sectors. In the form of a "smart label" the transponder electronics have been laminated into paper labels and plastic cards and this product is called Tag-it/sup TM/. This passive transponder has been developed for the target markets of express parcels and airline baggage though, over time, we expect that it will be adapted for use in other market sectors. In these two markets a flexible label is required where it can meet existing label specifications and form factors and be easily introduced into existing hardware. | Industrial traceability systems are designed to operate over complex supply chains, with a large and dynamic group of participants. These systems need to agree on processing and marketing of goods, information management, responsibility, and identification. In addition, they should guarantee context independence, scalability, and interoperability. In this paper, we first discuss the main issues emerging at different abstraction levels in developing traceability systems. Second, we introduce a data model for traceability and a set of suitable patterns to encode generic traceability semantics. Then, we discuss suitable technological standards to define, register, and enable business collaborations. Finally, we show a practical implementation of a traceability system through a real world experience on food supply chains. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,529 |
In this paper, we propose a novel method for discovering characteristic patterns in a time series called SAX-VSM. This method is based on two existing techniques - Symbolic Aggregate approximation and Vector Space Model. SAX-VSM automatically discovers and ranks time series patterns by their "importance" to the class, which not only facilitates well-performing classification procedure, but also provides an interpretable class generalization. The accuracy of the method, as shown through experimental evaluation, is at the level of the current state of the art. While being relatively computationally expensive within a learning phase, our method provides fast, precise, and interpretable classification. | The advent of the Big Data hype and the consistent recollection of event logs and real-time data from sensors, monitoring software and machine configuration has generated a huge amount of time-varying data in about every sector of the industry. Rule-based processing of such data has ceased to be relevant in many scenarios where anomaly detection and pattern mining have to be entirely accomplished by the machine. Since the early 2000s, the de-facto standard for representing time series has been the Symbolic Aggregate approXimation (SAX).In this document, we present a few algorithms using this representation for anomaly detection and motif discovery, also known as pattern mining, in such data. We propose a benchmark of anomaly detection algorithms using data from Cloud monitoring software. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,530 |
The coupling between the surface plasmons of two overlapping arrays of orthogonally oriented subwavelength elliptical holes has been demonstrated by terahertz time-domain spectroscopy over the $0.1\char21{}1\phantom{\rule{0.3em}{0ex}}\mathrm{THz}$ range. This enhanced transmission exhibits polarization sensitive frequency shift. Three-dimensional numerical simulations provide precise insight in the energy redistribution of the surface plasmons through the subwavelength holes. A simple theoretical model, demonstrating a strong coupling between the two subarrays, exhibits good agreement with the experimental data. | A terahertz (THz) extraordinary transmission from a complementary circular split-ring resonance (CSRR) on polyimide film is investigated via THz time-domain spectroscopy. A distinct single-peak resonance is observed due to the inductive–capacitive (LC) resonance when the THz polarization is perpendicular to the gap of CSRR. When the THz polarization is parallel to the gap of CSRR, a periodic multiple resonances phenomenon is observed. With the help of electric density distribution and surface current analysis, the origin of the frequency resonance is revealed. An asymmetric Fabry–Perot effect of the CSRR is found to induce aforementioned periodic resonances. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,531 |
This paper presents an integrative application of several numerical analytical techniques and associated analysis tools for design optimization and damage prediction in electronics packages and microsystems. This design-for-reliability approach is based on four different types of numerical techniques that allow (1) high-fidelity modelling, (2) reduced order modelling, (3) numerical optimization and (4) uncertainty analysis. The capabilities and the characteristics of the methods that underpin these four types of modelling and analysis tools are firstly investigated. The integration of the methods and tools is then examined and a methodology for coupling the tools in an optimization process is proposed. This numerical methodology involves the following steps: (1) Define sampling points for the design of interest by design of experiments (DOE) and calculate the design response at each DOE point using high-fidelity analysis; (2) construct reduced order models (ROM) for fast analysis using the obtained response values at the DOE points; (3) Undertake deterministic optimization in the defined design space by ROM; and (4) Probabilistic optimization by including variation and uncertainty of the design in the optimization task. This approach is suitable to address design-for-reliability requirements at early design stages in a wide range of application areas. The application of this approach is demonstrated in a case for minimizing the thermal fatigue damage of flip-chip solder interconnects. Design modifications show that this approach can provide improved reliability of the package and in the same time satisfy a number of design requirements. | Insulated-gate bipolar transistor (IGBT) power modules find widespread use in numerous power conversion applications where their reliability is of significant concern. Standard IGBT modules are fabricated for general-purpose applications while little has been designed for bespoke applications. However, conventional design of IGBTs can be improved by the multiobjective optimization technique. This paper proposes a novel design method to consider die-attachment solder failures induced by short power cycling and baseplate solder fatigue induced by the thermal cycling which are among major failure mechanisms of IGBTs. Thermal resistance is calculated analytically and the plastic work design is obtained with a high-fidelity finite-element model, which has been validated experimentally. The objective of minimizing the plastic work and constrain functions is formulated by the surrogate model. The nondominated sorting genetic algorithm-II is used to search for the Pareto-optimal solutions and the best design. The result of this combination generates an effective approach to optimize the physical structure of power electronic modules, taking account of historical environmental and operational conditions in the field. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,532 |
We present the first millimeter-wave aperture synthesis map of dust around a main-sequence star. A 3'' resolution image of 1.3 mm continuum emission from Vega reveals a clump of emission 12'' from the star at a position angle (P.A.) of 45°, consistent with the location of maximum 850 μm emission in a lower resolution James Clerk Maxwell Telescope/Submillimeter Common-User Bolometric Array (SCUBA) map. The flux density is 4.0 ± 0.9 mJy. Adjacent 1.3 mm peaks with flux densities of 3.4 ± 1.0 and 2.8 ± 0.9 mJy are located 14'' and 13'' from the star at P.A.'s of 67° and 18°, respectively. An arclike bridge connects the two strongest peaks. There is an additional 2.4 ± 0.8 mJy peak to the southwest, 11'' from the star at P.A. = 215°, and a marginal detection, 1.4 ± 0.5 mJy, at the stellar position, consistent with photospheric emission. An extrapolation from the 850 μm flux, assuming F1.3-0.85 mm ∝ λ-2.8, agrees well with the total detected flux for Vega at 1.3 mm and implies a dust emissivity index β of 0.8 We conclude that we have detected all but a very small fraction of the dust imaged by SCUBA in our aperture synthesis map and that these grains are largely confined to segments of a ring of radius 95 AU. | A retractable overhead guard assembly is provided to protect an operator of industrial trucks, such as a forklift operator, from falling objects. Said guard is retractable from a raised to a lowered position for operation in areas of low overhead clearance. A pair of substantially parallel extensible supports are attached to said truck. A guard is mounted on the upper ends of the supports and is manually slideable between a forward and rearward position and is maintained in either position by a locking mechanism. Said supports may include biasing means such as springs to counterbalance the weight of the guard and facilitate manual adjustment between raised and lowered positions. A locking mechanism is also provided on each support to retain the guard in a plurality of positions. Electrical interlocks prevent the raising of the lift beyond a predetermined height if the guard is not in the rearward and raised position where it offers maximum protection to the operator. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,533 |
Underwater sound propagation modeling is always one of the most important and popular problems in underwater warfare environment because sound is now the only medium which can propagate long range in the ocean.It is of important significance to the design and application of sonar and the surface or underwater deployment.The underwater sound propagation modeling theory is reviewed from seven main aspects and the application review of parallel algorithm in the underwater sound propagation modeling in the past decades is given.The developing trend of underwater sound propagation modeling has been put forward,which is 3D underwater sound propagation modeling and its parallel algorithm based on hardware equipment. | In this paper, a Kriging surrogate model is introduced to simplify the computation of underwater acoustic propagation and quantify the related uncertainty. By using a Kriging model to replace the single frequency and multi-frequency FOR3D acoustic model, the computational speed is increased by dozens of times while ensuring that the maximum mean square error is confined within 5%. In this way, the balance between efficiency and accuracy of the underwater acoustic propagation is achieved. On the basis of this Kriging surrogate model, the Monte Carlo simulation is also used to analyze the uncertainty of acoustic propagation loss, in terms of the posterior probability density distribution. Finally, the confidence intervals corresponding to different confidence levels are calculated in order to quantify the uncertainty of transmission loss. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,534 |
While the dynamics of complete wetting has been widely studied for liquids, the way a gas spreads on a solid is by far less known. We report here the events following the rise of a millimeter-size air bubble towards a textured material immersed in water and covered by a thin plastron of air. Bubbles contact the material either directly at the end of the rise, or after a few rebounds, which affects the initial shape of the bubble and the resulting dynamics of contact. Then, air spreads on the material, owing to surface tension and later buoyance, which tends to flatten further the bubble. The corresponding dynamics are shown to result from the inertial resistance of water, which explains how spreading bubbles reach centimeter sizes in typically 10 ms. | Publisher Summary The problem of determining the thickness of the dragged layer as a function of the speed of the motion of the film and of parameters characteristic of the properties of the fluid is of essential interest for practice. In the chapter, the thickness of the layer and the quantity of fluid carried along when pulling an infinite plate out of a vessel, which is sufficiently large to permit the neglecting of the effect of its walls and of the edges of the plate, is evaluated. The case of low velocity of motion of the plate is considered. In this case, all the surface of the liquid may be separated into two independent regions: (1) the region of the surface situated high above the meniscus and directly dragged by the plate, where the surface of liquid may be taken to be nearly parallel to the plate surface and (2) the region of the meniscus of liquid. The solutions of hydrodynamical equations in both independent regions are presented in the chapter and then both of the solutions that are found are connected. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,535 |
Hearth wearing is the key limit of a blast furnace campaign life. Hot metal flow pattern and temperature distributions are the two key variables to determine the rate and style of the hearth wearing. There are several strategies to control and reduce the hearth erosion, such as changing cooling water temperature and changing the heat transfer coefficient. In this paper, both cooling strategies are investigated using a comprehensive computational fluid dynamics (CFD) code, which was developed specifically for the simulation of blast furnace hearth. That program can predict the liquid flow patterns and temperature distributions of the hot metal as well as temperature profiles in the hearth refractory materials under different conditions. The results predicted by the CFD code were compared with actual industrial operation data. The cooling strategies are evaluated based on the energy analysis and effect on the hearth erosion.© 2005 ASME | Computer simulation and virtual reality visualization have evolved to become critical emerging technologies in creating immersive virtual environments for numerous fields. The ability to allow people to "go inside" these virtual environments provides a unique, and effective tool for understanding complex physical processes, and thus to innovate and to make significant improvements in a time and cost efficient way. It empowers people to work collaboratively and intuitively, and enables engineers to produce better designs as well as better solutions for troubleshooting and process/product optimizations more efficiently. As industry forges its way into the future, advanced computer simulation and visualization technologies will play an ever-increasing role in addressing the issues of productivity, energy, environment and quality, as well as workforce training to meet the challenges of tomorrow. The use of these technologies has already begun, and examples in steel manufacturing will be presented. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,536 |
Because of the direct relationship between removal rate and surface roughness in conventional grinding, ultra-precision finishing of hard coatings produced by chemical vapour deposition (CVD) usually involves several process steps with fixed and loose abrasives. In this paper, an innovative shape adaptive grinding (SAG) tool is introduced that allows finishing of CVD silicon carbide with roughness below 0.4 nm Ra and high removal rates up-to 100 mm 3 /min. The SAG tool elastically complies with freeform surfaces, while rigidity at small scales allows grinding to occur. Since material removal is time dependent, this process can improve form error iteratively through feed moderation. | Materials such as binderless tungsten carbide and silicon carbide have become ubiquitous in the fabrication of high-performance tooling and molding inserts. But while conventional grinding of these hard ceramics has been studied in depth, the theory underlying their super-fine finishing has been less extensively explored. In particular, the boundary in process parameters that delineates the brittle/ductile removal transition remains mostly undocumented. In this paper, we review some super-fine finishing methods for carbide materials, based on both bound and kinetic abrasive processes. The focus is then placed on modelling the interaction between material and abrasives under their respective process conditions, and deriving some useful criteria guiding the brittle/ductile transition. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,537 |
We present a mathematical model addressing the problem of cargo transport by container ship on the selected route where a certain number of containers of various masses and types are chosen out of a total number of containers available in loading port in order to achieve maximum transport profitability, provided maximum payload and transport capacity of container ship. Since the profitability is an index of operation efficiency expressed as a fraction, a respective mathematical model can be solved using linear fractional programming. The model was tested on a real-life example of feeder ship "Lipa" owned by "Losinjska plovidba", Rijeka, operating on route Rijeka-Gioia Tauro. | The paper introduces a mathematical problem that occursin marine container technology when programming the transportof a beforehand established number of ISO containers effectedby a full container ship from several ports of departure toseveral ports of destination at the minimum distance (time innavigation) or at minimum transport costs. The application ofthe proposed model may have an effect on cost reduction incontainer transport thereby improving the operation process inmarine transport technology. The model has been tested by usinga numerical example with real data. In particular, it describesthe application of the dual variables in the analysis ofoptimum solution. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,538 |
This article presents a summary description of the main safety criteria and requirements adopted in the ‘Guideline for Load and Resistance Assessment of Existing European Railway Bridges – advices on the use of advanced methods’ (SB-LRA, 2007. Prepared by Sustainable Bridges – a project within EU FP6. Available from: www.sustainablebridges.net) developed within the European project Sustainable Bridges – Assessment for Future Traffic Demands and Longer Lives. It shows selected safety formats recommended for the assessment of existing bridges, starting from the most simple, for the member level assessment, and ending with the most advanced, for the probabilistic non-linear assessment of a bridge system. The article also presents simplified methods for the probabilistic non-linear assessment of bridge systems. Furthermore, it shows probabilistic models for the resistance of selected types of bridge main carrying members that may be used in the simplified probabilistic assessment of existing railway bridges. | The specification of risk and reliability acceptance criteria is a key issue of reliability verifications of new and existing structures. Current target reliability levels in standards appear to have considerable scatter. Critical review of risk acceptance approaches to societal, economic and environmental risk indicates that an optimal design strategy is mostly dominated by economic aspects while human safety aspects need to be verified only in special cases. It is recommended to specify the target levels considering economic optimisation and the marginal life-saving costs principle, as both these approaches take into account the failure consequences and costs of safety measures. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,539 |
The purpose of this paper is to present a descriptive analysis of economic groups in Chile. It classifies the economic groups operating in the country, according to their ownership and governance patterns, describing typical ownership structures and concentration. From a governance perspective, groups in Chile are multi-layered structures. Some additional characteristics of groups are provided: i.e. diversification, size, ownership control and dispersion within the group, boards interlocking, and foreign participation in joint ventures with local groups. The Chilean structuring of groups is partly compared with the solutions implemented in Japan, Germany, England and the United States. | We test whether the use of bank debt as a governance mechanism is conditioned by the financial system in which firms operate. Our results indicate that the legal and institutional environment determines the use of bank debt to finance growth opportunities. Firms use bank debt to finance their growth opportunities when the country's banking system contributes to solving agency and asymmetric information problems and avoiding information monopoly costs. The evolutionary process of the financial systems in each country means that market imperfections such as information asymmetry or agency costs can have a diverse influence on firms' bank debt decisions. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,540 |
Recently, we proposed several complete orthonormal bases to increase the efficiency of modeling directional, high ::: numerical aperture fields for both the scalar and electromagnetic cases, based on the idea of imaginary focus ::: displacements. Their elements, which can be thought of as nonparaxial analogs of Laguerre-Gauss beams, are ::: analytic solutions to the wave equation in free space and can be optimized for the particular angular spread (NA) ::: using a single parameter corresponding to the imaginary displacement. The scattering of these basis elements ::: off spherical particles can be calculated analytically, as can also the resulting forces and torques exerted on ::: the particle by any linear combination of these fields. Applications involving both fully coherent and partially ::: coherent fields are discussed. | A microscopy system has been constructed that is capable of simultaneously acquiring both traditional Raman spectra as well as angle-resolved elastic-scattering patterns using a single focused laser spot less than 10 μm wide. The elastic-scattering signal was analyzed by generalized Lorenz-Mie theory, representing what we believe to be the first experimental validation of the theory's prediction of angular backscatter from single spheres. The microscope system exhibits 3 nm precision in predicting sphere diameters, while simultaneously yielding high-quality Raman signals. Applications to single cell analysis are envisioned. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,541 |
This paper is concerned with the determination of bond energies using the comparative rate single pulse shock tube technique. The relationships between high pressure unimolecular rate constants, equilibrium constants for reaction, the enthalpies of reaction and the heat of formation of individual radicals formed from the breaking of chemical bonds are developed. A detailed description of the physical phenomena and experimental procedures is given. The special aspects of comparative rate single pulse shock tube experiments are described. The treatment of data and in particular the dependence on a variety of ancillary information for the extraction of bond energies or radical heats of formation is illustrated with specific examples. A summary of the heats of formation of the organic radicals determined by this method will be presented and compared with determinations arrived at by other procedures. The results are generalized in the context of the high temperature stability of polyatomic organic molecules. | This paper describes the present situation regarding chemical kinetic databases for the simulation of the combustion of liquid fuels. Past work in the area is summarized. Much is known about the reactions of the smaller fragments from combustion processes. In order to describe real liquid fuels there is the need for an understanding of how the larger organic fuels are broken down to these fragments. The type of reactions that need to be considered are described and the breakdown of heptane is used as an example. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,542 |
The state of the art technologies today have revolutionized the business processes of an organization by providing effective storage, retrieval and communication mechanisms. The most desirable feature of this technology is the secure data sharing among various business partners. Most of the organizations today rely on standard communication channels to share information among interacting partners. These standalone systems provide the intended benefits to some extent; but the communication between two heterogeneous work processes is a difficult task. To cope with the issue, developed countries like Germany, France, Sweden, Estonia and Denmark have developed centralized communication infrastructures for government and private/business organizations. Such infrastructure serves as a backbone for secure information exchange between G2G (Government to Government) and G2B (Government to Business). In developing countries like Pakistan, Bangladesh and Sri Lanka although the communication system is based on IT but segregated systems/processes are being used for information sharing among various organizations. The communication between governmental and private organizations is done in a traditional manner, which requires a cumbersome process of data formatting and information exchange. In this paper, we will explore and analyze the opportunities and constraints to develop/deploy the centralized communication infrastructure (CIPS: Centralized Information Processing System) in a developing country perspective. The paper presents the case study from Pakistan and analyzes the constraints and opportunities to develop such centralized infrastructure for information exchange. | Significant technological advancement in the current electronic era has influenced the work processes of private and government business entities. E-Government is one such area where almost every country is emphasizing and automating their work processes. Software architecture is the integral constituent of any software system with not only cumbersome modeling and development but require heedful evaluation. Considering this aspect we have highlighted in this paper, security evaluation of an ongoing e-society project ESAM using Architectural Tradeoff Analysis Method (ATAM). ESAM is a web based system intended to provide e-services to the Swedish community residents. ATAM is primarily used for architectural evaluation aligned with the quality goals i.e. performance, availability and modifiability of an organization. We present research analysis for characterization, stimuli, and architectural decisions to evaluate software architecture with respect to security measures using ATAM. This security characterization will serve as a tool to evaluate security aspects of a software architecture using ATAM. We believe that ATAM capability of evaluating software security will provide potential benefits in secure software development. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,543 |
A connector for a coaxial cable consists of a terminal provided with a connection, an insulating terminal holder for receiving the terminal, which has a pair of opposed first and second lids at one end at a side wherefrom to receive the terminal, the first lid, when closed, locking the terminal in the terminal holder, and a conductive shield cover mounted on the terminal holder, the shield cover having a holding means at one end toward the coaxial cable, the connection hole of the terminal and the holding means being aligned with each other when the shield cover is mounted on the terminal holder, wherein when the coaxial cable is advanced, the conductor is inserted into the connection hole and the braid is located on the holding means to position the conductor and the braid at one time. The load on the conductor is reduced, the manufacturing process is simplified, and reliability is improved. | SUMMARY The consistency of the word usage in a previously unknown nine-stanza poem attributed to Shakespeare with that of the Shakespearean canon is examined using a nonparametric empirical Bayes model. We consider also poems by Jonson, Marlowe and Donne, as well as four poems definitely attributed to Shakespeare. On balance, the poem is found to fit previous Shakespearean usage reasonably well. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,544 |
A new German government funded project for a resistive fault current limiter has started in September 2009 (ENSYSTROB) and is presented. The consortium includes partners from industry, research centers and utilities. It aims the construction of a 3-phase medium voltage current limiter (12 kV, 800 A) for the protection of the domestic supply in a power plant. A special feature of this application is the presence of large in-rush currents (4100 Ap for 50 ms, 1800 A for 15 s). The superconducting components are bifilar pancake coils consisting of pairs of YBCO-tapes in face to back configuration. Successful limitation experiments on prototype components with prospective currents in the whole range are shown. Also the stability with respect to high voltage could be demonstrated. The AC-losses under normal operation are shown, by simulation and experiment, to be smaller than the heat input of the current leads. The current limiting components are compared with similar elements based on BSCCO 2212 bulk material (Nexans SuperConductors). | This paper introduces a new design solution for the high-power superconducting fault current limiter (SFCL). The device consists of concentric sections with a circular cross-section shape which are connected in series in such a way that the current in adjacent sections flows in mutually opposite directions. The analysis of efficiency of various designs and optimization of their geometry and dimensions was performed through numerical simulations. They show that the higher number of sections gives the ability to substantially decrease the amount of superconducting materials and to reduce hysteresis losses. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,545 |
This paper describes the research and development of a methodology to identify the type of information required by the service advisor (CSA) within customer contact centre (CCC) environment. Data was collected through case studies carried out within five customer contact centres to derive the categories for customers and advisors based on demographic, experience, business value and behavioural attributes. We provide the methodology to develop a fuzzy expert system which assigns a new customer or advisor to the predefined categories. The authors have explained the steps which were followed for the development of the fuzzy expert system. A prototype system has been designed and developed to identify the type of customer and CSA based on the demographic, experience and behavioural attributes. The authors illustrate analysis with real data, based on the work with large scale customer contact centres. Validation of the information requirement model was carried out at the contact centres | Previous research has established links between employee attitudes and customer satisfaction. Little theory has been used to help explain and build on the results of these studies. A theoretical model of the employee attitude-customer satisfaction process is proposed based on Bagozzi's (1992) model of attitudes, intentions and behavior. Employee attitudes and intentions, and customer satisfaction data from a service-oriented organization with 160 offices is used to provide an initial test of the usefulness of the model. Cross-validations of the model with and without common method variance were conducted. The results provide strong support for the model. Suggestions are offered on extensions of the model in future research. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,546 |
We propose a method for VLSI interconnect global routing that can optimize routing congestion, delay and number of bends, which are often competing objectives. Routing flexibilities under timing constraints are obtained and exploited to reduce congestion subject to timing constraints. The wire routes are determined through gradual refinement according to probabilistic estimation on congestions so that the congestion is minimized while the number of bends on wires are limited. The experiments on both random generated circuits and benchmark circuits confirm the effectiveness of this method. | We present a new performance and routability driven routing algorithm for symmetrical array-based field-programmable gate arrays (FPGAs). A key contribution of our work is the overcoming of one essential limitation of the previous routing algorithms: inaccurate estimations of routing density that were too general for symmetrical FPGAs. To this end, we formulate an exact routing density calculation that is based on a precise analysis of the structure (switch block) of symmetrical FPGAs and utilize it consistently in global and detailed routings. With an introduction to the proposed accurate routing metrics, we describe a new routing algorithm, called cost-effective net-decomposition-based routing, which is fast and yet produces remarkable routing results in terms of both routability and net/path delays. We performed extensive experiments to show the effectiveness of our algorithm based on the proposed cost metrics. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,547 |
The Electromagnetic Code - Basic Scattering Code, Version 3, is a user oriented computer code to analyze near and far zone patterns of antennas in the presence of scattering structures, to provide coupling between antennas in a complex environment, and to determine radiation hazard calculations at UHF and above. The analysis is based on uniform asymptotic techniques formulated in terms of the Uniform Geometrical Theory of Diffraction (UTD). Complicated structures can be simulated by arbitrarily oriented flat plates and an infinite ground plane that can be perfectly conducting or dielectric. Also, perfectly conducting finite elliptic cylinder, elliptic cone frustum sections, and finite composite ellipsoids can be used to model the superstructure of a ship, the body of a truck, and airplane, a satellite, etc. This manual gives special consideration to space station modeling applications. This is a user manual designed to give an overall view of the operation of the computer code, to instruct a user in how to model structures, and to show the validity of the code by comparing various computed results against measured and alternative calculations such as method of moments whenever available. | This paper describes a technique whereby feed equivalent surface currents generated in the ESL BOR (Body of Revolution) code are linked to the NEC-REF code to generate reflector surface currents, and then both sets of surface currents are linked to the NEC-BSC code to analyze a scattering problem. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,548 |
As a good user interface design is important for the success of an app, so is a good API for the success of a Web service. Within the RESTful Web services community there is a need for a systematic approach in knowledge sharing, for which patterns are particularly suitable. Using a RESTful service to achieve a certain goal often requires multiple client-server interactions, i.e., to have a conversation. While patterns of such RESTful conversations can be uncovered from existing APIs' usage scenarios, or the service engineering literature, they have never been gathered in a pattern language, nor properly visualized with a Domain Specific Modeling Language (DSML). These patterns provide valuable input for API designers, as well as API consumers, by establishing a common vocabulary to describe recurring conversations. To do so, this paper uses RESTalk, a DSML, to model the basic RESTful conversation patterns structured around the life cycle of a resource (create, discover, read, edit, delete, protect) by showing the corresponding sequences of HTTP request-response interactions. We show how the resulting pattern language can be applied to individual resources, or also collections of resources. | This specification describes a pattern of use that allows HTTP clients ::: to automatically retry POST requests in a manner that assures no ::: unintended side effects will take place, and defines mechanisms to ::: allow implementations to automatically determine when such patterns ::: are supported. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,549 |
Mammography is routinely used to screen for breast cancer. However, the radiological interpretation of mammogram images is complicated by the heterogeneous nature of normal breast tissue and the fact that cancers are often of the same radiographic density as normal tissue. In this work, we use wavelets to quantify spectral slopes of breast cancer cases and controls and demonstrate their value in classifying images. In addition, we propose asymmetry statistics to be used in forming features, which improve the classification result. For the best classification procedure, we achieve approximately 77% accuracy (sensitivity=73%, specificity=84%) in classifying mammograms with and without cancer. Copyright © 2017 John Wiley & Sons, Ltd. | This paper introduces an image denoising procedure based on a 2D scale-mixing complex-valued wavelet transform. Both the minimal (unitary) and redundant (maximum overlap) versions of the transform are used. The covariance structure of white noise in wavelet domain is established. Estimation is performed via empirical Bayesian techniques, including versions that preserve the phase of the complex-valued wavelet coefficients and those that do not. The new procedure exhibits excellent quantitative and visual performance, which is demonstrated by simulation on standard test images. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,550 |
1. Introduction.- 2. The Complex Dielectric-Constant Tensor ?ij(?,k) and Normal Waves in a Medium.- 3. The Tensor ?ij(?,k) in Crystals.- 4. Spatial Dispersion in Crystal Optics.- 5. Surface Excitons and Polaritons.- 6. Microscopic Theory. Calculation of the Tensor ?ij(?,k).- 7. Conclusion.- A.1 Crystal-Symmetry Notation.- A.2 Information from Space Group Theory.- A.2.1 Classification of the States of Mechanical Excitons.- Notation.- References. | In 1948 Tellegen [Philips Res. Rep. 3, 81 (1948)] suggested that an assembly of the lined up electric-magnetic dipole twins can construct a new type of an electromagnetic material. Until now, however, the problem of creation of the Tellegen medium is a subject of strong discussions. An elementary symmetry analysis makes questionable an idea of a simple combination of two (electric and magnetic) dipoles to realize local materials with the Tellegen particles as structural elements. In this paper we show that in search of sources with local junctions of the electrical and magnetic properties one cannot rely on the induced parameters of small electromagnetic scatterers. No near-field electromagnetic structures and no classical motion equations for point charges give a physical basis for realization of sources with a local junction of the electrical and magnetic properties. We advance a hypothesis that local magnetoelectric (ME) particles should be physical objects with eigenmode oscillation spectra and noncla... | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | yue_Hant | 24,551 |
A voltage regulator has an output transistor which controls current flow in the field winding of a generator charging a battery, and a resistance chain for sensing the output voltage of the generator. Connected to the resistance chain is a Zener diode which controls conduction of the output transistor, and a resistance chain includes a thermistor for providing temperature compensation. The thermistor is bridged by the collector-emitter path of a transistor and biasing means is provided for controlling the base voltage of the transistor so that the regulated voltage varies with temperature in a predetermined manner. | Using data from an experimental evaluation in two Canadian provinces, we found that offering an earnings supplement to single mothers in place of welfare altered rates of marriage and cohabitation, but that the direction of the effects varied by province. Our findings suggest that research on the relationship between women’s economic well-being and marital decisions at the national level is likely to mask important variation at the local level. After eliminating several explanations for the opposite effects in the two provinces, we propose that local labor markets and local policy contexts are potentially important mediating characteristics of marriage and cohabitation. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,552 |
ns-3 is an open-source network simulator with support for simulating 3GPP LTE cellular network. This paper presents three extensions to the LTE module of ns-3, enhancing its capability of simulating scenarios with more sophisticated user mobility requirements. The first extension implements additional features in the UE measurements function. The second extension delivers additional handover algorithms and a modular framework for ns-3 users to incorporate their own handover algorithms. At last, the third extension enables automatic network attachment using the initial cell selection procedure. The modelling of these extensions refers to 3GPP standard specifications. The resulting models have been validated using the ns-3 testing framework. | In this paper, we present an open source simulation model for the ns-3 simulator that allows the simulation of LTE handover scenarios, to support the design and evaluation of handover decision algorithms. In addition to the features supported by other publicly available open source LTE simulators, such as mobility, propagation, channel, PHY and MAC modeling, our model provides additional features such as the modeling of the RRC protocol, the MAC random access procedure, and the X2, S1 and S11 interfaces. On top of these features, the LTE handover procedure is modeled, following closely the 3GPP specifications. We present in detail the characteristics of each component of the simulation model, highlighting the modeling assumptions that were made in each case. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,553 |
AIM ::: To determine post-operative pain in children following treatment in the dental chair and its relation to dental anxiety. ::: ::: ::: METHODS ::: A group of 125 children, aged 5 to 18 years, attending for dental treatment had their pain recorded post-operatively using the revised version of the Faces Pain Scale (FPS-R) and the Visual Analogue Scale (VAS). Baseline anxiety scores were also recorded using the Modified Child Dental Anxiety Scale (faces) (MCDASf). ::: ::: ::: RESULTS ::: The mean MCDASf score was 20.1. Post-operative pain was reported in 62% of children at 2 hours, 51% at 4, and 47% at 6 hours. The surgical subgroup reported the most pain (79%), whereas the conservative treatment for primary teeth group reported the least pain (37%). Anxious patients (MCDASf > = 17) were more likely to report pain than less anxious patients at 2 (p=0.02) and 6 (p=0.03) hours post-operatively. ::: ::: ::: CONCLUSION ::: Dental procedures are associated with post-operative pain in children. Anxious patients are more likely to report pain. | Purpose ::: To study pain perception in 10–15-year-olds, during and after uncomplicated extractions of bilateral maxillary premolars. The study investigated pain’s natural course and made comparisons between the first and second extractions. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,554 |
In this paper, we calculate the transient eddy-current response of a driver pickup probe due to a conducting plate by means of series expansions. We consider an excitation current in the driver coil that rises exponentially with time toward a constant value, the step function current being a special case with zero time constant. We find the transient response from the frequency domain expressions for the induced electromotive force in the pickup coil by using the inverse Laplace transform. Usually, the field of the excitation coil is expressed in the form of a Bessel integral with respect to the radial spatial frequency. Here, however, to improve computational efficiency, we approximate the integral as a series expansion by truncating the solution domain at a large but finite radius and setting the field on the truncation boundary to zero. The series is a sum of terms containing discrete spatial frequencies defined by the zeros of the first-order Bessel function of the first kind. We then form an inner summation from the temporal frequency-dependent terms in order to facilitate an analytical inverse Laplace transformation to the time domain. We present two alternative expansions for the inner sum. One is constructed with reference to the short time regime and the other with respect to the long time limit. Numerical results show good agreement between the alternative series approximations at a wide range of intermediate times. | A handbook of mathematical functions that is designed to provide scientific investigations with a comprehensive and self-contained summary of the mathematical functions that arise in physical and engineering problems. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,555 |
The surface tension of liquid tin has been measured by the sessile-drop technique as a function of temperature, in the range 232 ⩽T (°C) ⩽ 800 and under different atmospheres. It is shown that oxygen strongly affects the surface tension values and that, under “nominally” very clean conditions, a considerable scatter of experimental results occurs. This scatter can be explained by taking into account kinetic factors, especially those related to the gaseous fluxes around the molten drop. By this procedure, a number of experimental results can be singled out, which corresponds to “clean” surface conditions. On the basis of these results, the following expression for surface tension politherm is proposed: σ(mN m−1 = 581-0.13) (t-232). | We present a solder pump method that injects conductive material into a device wafer to form low-resistance through-silicon vias (TSVs). Building on previous work that exploits the Gibbs-Thomson effect, this pump geometry uses a reusable wafer set to produce a pattern of U-shaped reservoirs into which solder balls are loaded. After introduction of the device wafer with a corresponding pattern of through-wafer-etched holes, reflow results in the complete transfer of the solder from the reservoirs into the device structure to produce the vias. This approach forms the basis of a rapid low-cost batch-fabrication process for TSVs. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,556 |
Several types of vegetation restoration have been implemented on the Loess Plateau in China to control soil erosion and improve soil quality. Different revegetation types, however, have varying effects on soil structure; effects on the pore network of aggregates are especially not well understood. We used synchrotron-based high-resolution X-ray micro-computed tomography to quantify the microstructure of soil aggregates under four types of revegetation and an active cropland on the plateau. Five aggregates (3–5 mm) collected from the topsoil at each site were scanned at a voxel resolution of 3.25 μm, and the aggregate pore structure was visualized and quantified with ImageJ. Total porosities, >75 μm porosities, fractions of elongated pores, 3D mass fractal dimensions, and connectivity were higher and the numbers of pores, grassland > woodland > pastureland. We recommend shrub plantation and natural grassland for the revegetation of degraded land on the Loess Plateau. | Bone geometry is commonly measured on computed tomographic (CT) and X-ray microtomographic (μCT) images. We obtained hundreds of CT, μCT and synchrotron μCT images of bones from diverse species that needed to be analysed remote from scanning hardware, but found that available software solutions were expensive, inflexible or methodologically opaque. We implemented standard bone measurements in a novel ImageJ plugin, BoneJ, with which we analysed trabecular bone, whole bones and osteocyte lacunae. BoneJ is open source and free for anyone to download, use, modify and distribute. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,557 |
High pressure/high temperature (HP/HT) subsea pipelines are increasingly being designed to buckle in a controlled manner in order to relieve axial loading. HP/HT pipelines often require insulation coating to prevent hydrate formation and to help manage internal corrosion. Thick wall polymer coatings are a common choice of insulation material in such cases. A change in local bending stiffness, for example due to the change in external coating at field joints, can result in strain localisation leading to a higher local curvature than would have occurred in an otherwise homogenous system. Industry knowledge of the influence of thick wall polypropylene is limited. The proportion of total bending stiffness attributed to the coating is much larger than typically observed in non-insulated coating systems. The polymer coating is likely to behave in an elastic manner even at elevated strain levels, i.e. those typically observed in lateral buckles. It is shown herein that significant strain intensification can occur at field joints even when the field joints appear to be of a similar configuration to that of the nominal linepipe coating. This paper presents the results of finite element (FE) analyses (using solid body elements) that have been employed to demonstrate, in highly loaded conditions such as laterally buckled pipelines, the influence of thick wall insulation coatings on strain intensification at field joints. Furthermore analytical equations have been derived as an alternative methodology for calculation of strain intensification at field joints. It is demonstrated that, even in highly loaded conditions, the analytical relationship correlates very well to results determined via the FE technique.Copyright © 2009 by ASME | Sandwich pipes in which the core material performs both thermal insulation and structural function are viewed as a lightweight alternative to conventional pipe-in-pipe systems in which insulation material carries no loading. Developing a suitable method that permits the joining of sandwich pipes in an efficient manner is essential for their successful application. In this paper, the mechanical response of a swaged field joint between sandwich pipes subjected to bending is investigated using a series of finite element models. In order to gain a thorough understanding of the response of the joint components to installation based loadings, parametric studies are carried out to establish the effect of the inner pipe thickness, cutback length, and stiffness of the field joint filler on the strain concentration at the joint, with particular focus on the swaged weld region and the girth weld region. The influence of interface adhesion properties and weld metal yield strength on the variation of strain intensity is also evaluated. Numerical studies show that increasing filler stiffness and maintaining a cutback length less than 2.5 times the radius of the inner pipe could produce lower strain intensity at the two regions of interest. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,558 |
Investment planning models inform investment decisions and government policies. Current models do not capture the intermittent nature of renewable energy sources, restricting the applicability of the models for high penetrations of renewables. We provide a methodology to capture spatial variation in wind output in combination with transmission constraints. The representation of wind distributions using stochastic approaches or using extensive historic data sets exceeds computational constraints for real world application. Hence we restrict the amount of input data, and use bootstrapping to illustrate the robustness of the results. For the UK power system we model wind deployment and the value of transmission capacity. | Special conditions in electric networks complicate the analysis of the geographic scope of the horizontal market power. Unlike the conventional setting where a firm exercises market power by restricting its own production, there could be situations in constraining electrical networks where a generator would exercise market power by increasing its production in order to block transmission of a disproportionate amount of competing generation. A model with a set of Cournot firms, a collection of competitive fringe participants and an explicit representation of the electrical network illustrates the possible strategic interactions. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,559 |
where t t0 > 0; r 2 C .Œt0;1/I .0;1//; p; q 2 C.Œt0;1/IR/; f 2 C.R;R/; k1 2 C .R; R/; and k2 2 C.R ; R/: Throughout the paper, it is assumed that the following conditions are satisfied: (a) p.t/ 0 for all t t0I (b) f .x/=x K for some constant K > 0 and all x 2 Rn f0g I (c) q.t/ 0 for all t t0; and q.t/ 6 0 on Œt ; 0/ for any t t0I (d) k 1.u; v/ 1vk1.u; v/ for some constant 1 > 0 and all .u; v/ 2 R I (e) uvk2.u; v/ 2k 1.u; v/ for some constant 2 > 0 and all .u; v/ 2 R I (e1) uvk2.u; v/ 2uk1.u; v/ for some constant 2 > 0 and all .u; v/ 2 R: Recall that a function xW Œt0; t1/ ! . 1;1/; t1 > t0; is called a solution of Eq. (1.1) if x.t/ satisfies Eq. (1.1) for all t 2 Œt0; t1/: In what follows, it is always assumed that solutions of Eq. (1.1) exist on Œt0;1/: A solution x.t/ of Eq. (1.1) is called oscillatory if it has arbitrary large zeros, otherwise it is called nonoscillatory. Equation (1.1) is called oscillatory if all solutions are oscillatory. In the relevant literature, till now, the oscillation behavior of solutions of linear and nonlinear second-order differential equations has been the subject of intensive investigations for many authors. For some related papers or books on the subject, see, e.g., [1–39]. 1 Gaziosmanpasa University, Tokat, Turkey. 2 Ondokuz Mayis University, Samsun, Turkey. | A class of even order damped differential equations with distributed deviating arguments are investigated. Several new criteria that ensure the oscillation of solutions are obtained. To demonstrate the validity of the results obtained, two examples are given. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,560 |
Pollution flashover caused by long-term contamination and moisture of the transmission line insulators is one of the main dangers for the safe operation of the power system. To study the contamination characteristics of the insulators in different weather conditions enables us to understand the contamination conditions of the insulators and take effective measures to prevent the pollution flashover accidents. Through the artificial contamination test and air dynamic simulation of the XWP2-160 double-shed insulator and FC160P glass insulator, it is concluded the influence of pollution contamination characteristic and flow field distribution characteristic in different wind speed and wind direction. The main factors that affected the insulator contamination characteristic were also analyzed, which can provide some guidance to the configuration of transmission lines insulators and antifouling work. | Insulator contamination is one of many serious problems for power systems. Outages due to insulator contamination flashover may affect a wide area and continue for a long time. Also, the corona noise causes radio and TV interference. Therefore, efforts have been made by many around the world to prevent such phenomena. Presently, fog type and semi-conducting glaze insulators have been developed, and successfully used. However, the former cannot suppress the corona and the latter has a subject to study from the viewpoint of thermal stability in heavy contamination conditions. A new concept insulator, with a stress graded zone on the bottom surface, has been studied. It has been determined that a dry band is not formed on this stress graded zone and a long dry band is formed at the first rib. This means the insulator has a high discharge starting voltage and high contamination withstand voltage. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,561 |
In this paper, we describe the development of a humansized 3DOF finger module for human-care services, having multi-directional passive compliance and the ability to estimatie external torque. In order to achieve the above characteristics, Silicone Gum Cushions (SGC) are used at the finger-tip and the MP joint (Metacarpal-phalangeal joint). These SGCs have a hollow shape and deform easily. The elastic deformation of SGC enables the robot to react softly to the external forces excerted from multiple directions. Furthermore, these forces can be inferred by measuring the pressure in the SGC's hollow. The basic characteristics of the module's passive compliance and its accuracy in sensing external forces are examined through several experiments. In addtion, in order to confirm the possible application of this finger to a human-care services, we executed an experiment that simulates the motion of wiping a human body, taking advantage of the system's merits. | A highly anthropomorphic human scale robot hand designed for space based operations is presented. This five finger hand combined with its integrated wrist and forearm has fourteen independent degrees of freedom. The device approximates very well the kinematics and required strength of an astronaut's hand when operating through a pressurized space suit glove. The mechanisms used to meet these requirements are described in detail along with the design philosophy behind them. Integration experiences reveal the challenges associated with obtaining the required capabilities within the desired size. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,562 |
A broadband offset-parallel-parallelograms printed endfire antenna is presented. The proposed antenna consists of a pair of offset parallel parallelograms, the driver dipoles, the offset double-sided parallel-strip line, and a reflector. The top and bottom patches are printed in parallel on two sides of a substrate plane. The characteristics of the offset parallel parallelograms are studied and discussed. The calculated results fit in well with the results obtained by simulation with ANSYS HFSS. The broadband endfire radiating patterns were achieved. The measured bandwidths were 73.3% for the frequency band (0.89-1.92 GHz), and the gain was about 3.3-4.8 dBi in the operating band. | This communication proposes a high-gain bow-tie antenna operating over the frequency band of 5.5–8 GHz. The proposed antenna is comprised of a microstrip-to-slot transition line connected to bow-tie radiators. Seven slabs of split-ring resonator (SRR) unit cells are integrated into the orthogonal plane of antenna substrate to enhance its gain. Each slab consists of $2 \times 7$ double-sided SRR unit cells. A prototype of the antenna is fabricated and measured. The results indicate that the reflection coefficient is better than −10 dB over the frequency band of 3.5–8 GHz. The measured antenna gain varies from 10.2 to 13.8 dBi over a frequency range of 5.65–7.8 GHz. The measured radiation efficiency corresponds to 90% at 7 GHz. The cross polarization is better than −30 dB in the $E$ -plane at 6.5 GHz. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,563 |
We demonstrate a large-mode-volume transverse-electric-polarized \lambda /4 shifted distributed feedback (DFB) cavity on silicon-on-insulator (SOI). A 2.86 mm-long DFB cavity with sidewall corrugation on the ridge is fabricated on a silicon rib waveguide. The cavity structure is designed to enlarge both the longitudinal and transversal mode profiles of the cavity to enclose more luminescent media. Design strategies are verified by both finite difference time domain simulation and experiments. A linewidth of 69 pm and an extinction ratio of 15 dB is obtained, indicating not only the well confinement of the longitudinal mode, but also its well stretching to the cavity ends. The mode volume is 75.39 \mu m3. | In this letter, we provided a proof-of-concept study on the anti-symmetric sampled Bragg grating (ASBG) with π equivalent phase shift (π-EPS) in silicon-on-insulator (SOI). A four-channel narrow-band passive filter array was fabricated. Experimental results show that the 0th-order resonance is totally eliminated, while the +1st-order resonance is maintained. In addition, 3-D finite-difference-time-domain (3-D-FDTD) algorithm was also used to analyze the other characteristics of this structure, such as the radiation phenomenon caused by anti-symmetric feature. Since the anti-symmetric basic grating combined with sampling pattern could equivalently realize various grating structures, ASBG can be used for multi-wavelength photonic devices, such as DFB laser array, sensor array, electrooptic modulator array, and so on. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,564 |
Flow visualization and Reynolds-stress measurement were combined in an investigation of a turbulent boundary layer in a water channel. Hydrogen bubbles were used to visualize the flow; a laser-Doppler anemometer capable of measuring two velocity components was applied to measure the instantaneous value of the Reynolds stress. Owing to the three-dimensional, time-dependent character of the flow it was rather difficult to identify flow structures from measured velocity signals, especially at larger distances from the wall. Despite this difficulty a method based on the instantaneous value of the Reynolds stress could be developed for detecting bursts in the wall region of the boundary layer. By this method the three-dimensional, time-dependent character of the flow is taken into account by attributing to the same burst ejections occurring successively with very short time intervals. This identification procedure is based on a comparison on a one-to-one basis between visualized flow structures and measured values of the Reynolds stress. The detected bursts were found to make a considerable contribution to the momentum transport in the boundary layer. | The microtopography of a gravel bed river has been shown to generate turbulent flow structures that originate from shear flow generated in the near-bed region. Although field and laboratory measurements have shown that such flows contain a range of coherent flow structures (CFS), the origin, evolution, and characteristics of the turbulent structures are poorly understood. Here we apply a combined experimental methodology using planar laser-induced fluorescence and particle imaging velocimetry (LIF-PIV) to measure simultaneously the geometric, kinematic, and dynamic characteristics of these CFS. The flow structures were analyzed by applying standard Reynolds decomposition and Lagrangian vortex detection methods to understand their evolution, propagation, and growth in the boundary layer and characterize their internal dynamical complexity. The LIF results identify large, individual, fluid packets that are initiated at the bed through shear that generate a bursting mechanism. When these large individual fluid packets are analyzed through direct flow measurement, they are found to contain several smaller scales of fluid motion within the one larger individual fluid parcel. Flow measurements demonstrate that near-bed shear controls the initiation and evolution of these CFS through merging with vortex chains that originate at the bed. The vortex chains show both the coalescence in the formation of the larger structures and also the shedding of vortices from the edges of these packets, which may influence the life span and mixing of CFS in open channels. The life span and geometric characteristics of such CFS are critical in influencing the duration and intensity of near-bed stresses that are responsible for the entrainment of sediment. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,565 |
Institute of Experimental Meteorology initiated investigations of anthropogenic contamination (AC) and its influence on the near-earth environment and orbiting vehicles. These investigations are based on rocket experiments on simulation of the effects of gas-dust fluxes at the rate of 7–8 km/s on vehicle optical elements under real space conditions. The fluxes are generated by rocket-borne explosive generators. | In this paper, to determine whether an economically attractive opportunity exists in space debris removal industry, we establish a Commercial Opportunity Evaluation Model. Based on costs, risks and benefits models, we formulate an evaluation function: COM=Benefits (1-Risk)-Cost. WhenCOM is greater than 0, we think a commercial opportunity exists. It is used to evaluate the best alternative in different orbits. We find it is the most valuable to adopt ground-based laser in LEO( 4157887.6272 COM = ). Besides, we obtain the criticality risk (0.697(LEO); 0.713(MEO); 0.789(GEO)) in different orbits. Introduction The definition of commercial opportunity are diverse, it will be influenced by many factors. In the emerging industry of space debris removal, there is no mature commercial system. So we should find an accepted standard to judge whether a viable commercial opportunity exist. The Foundation of Model Cost, Risk and Benefit models There are some empirical formulas about the factors to the alternatives evaluation. And the time functions about the factors can be deduced: 1 1 1 2 2 0 ( ) ( ) ( ) d V V C t m i A h round E i D V Fdl t round V V = + + ∫ g g g g g g ; (1) ( ) ( ) ( ) ( ) j P t R t e G q M + = + g ; (2) | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,566 |
Method and apparatus for melting rod-shaped material 12. This is continuously displaced in the direction of the rod axis towards an induction coil (5), disposed at the lower end (12a) of the rod, which has an opening coaxial with the rod and which is supplied with an alternating current. An induction coil (5) is used of which the axial dimension is several times smaller than the radial dimension. Preferably, a so-called flat-coil is used. The induction coil has an opening (5c) which is smaller than the rod diameter. On melting the lower end (12a) of the rod is held with its end face at a substantially constant spacing above the induction coil (5). The method and apparatus are suitable for the production of metal powder and for the direct production of shaped parts. | The PAGES research community works toward improving our understanding of the Earth's changing environment. By placing current and future global changes in a long term perspective, they can be assessed relative to natural variability. Since the industrial revolution, the Earth System has become increasingly affected by human activities. Natural and human processes are woven into a complex tapestry of forcings, responses, feedbacks and consequences. Deciphering this complexity is essential as we plan for the future. Paleoenvironmental research is the only way to investigate Earth System processes that operate on timescales longer than the period of instrumental records. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,567 |
The first quantitative evaluation of the quality of corporate firewall configurations appeared in 2004, based on Check Point Firewall-1 rule sets. In general, that survey indicated that corporate firewalls often enforced poorly written rule sets. This article revisits the first survey. In addition to being larger, the current study includes configurations from two major vendors. It also introduces a firewall complexity. The study's findings validate the 2004 study's main observations: firewalls are (still) poorly configured, and a rule -set's complexity is (still) positively correlated with the number of detected configuration errors. However, unlike the 2004 study, the current study doesn't suggest that later software versions have fewer errors. | Modern SCADA networks are connected to both the companys enterprise network and the Internet. Because these industrial systems often control critical processes the cyber-security requirements become a priority for their design. This paper deals with the network security in SCADA environment implemented by firewall devices. We proposed a method for verification of firewall configurations against a security policy to detect and reveal potential holes in implemented rule sets. We present a straightforward verification method based on representation of a firewall configuration as a set of logical formulas suitable for automated analysis using SAT/SMT tools. We demonstrate how such configuration can be analyzed for security policy violation that can be inferred from a security policy specification of an industrial automation system. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,568 |
We prove some new pointwise-in-energy bounds on the expectations of various spectral shift functions associated with random Schrodinger operators in the continuum having Anderson-type random potentials in both finite-volume and infinite-volume. These estimates are a consequence of our new Wegner estimate for finite-volume random Schrodinger operators. For lattice models, we also obtain a representation of the infinite-volume density of states in terms of a spectral shift function. For continuum models, the corresponding measure is absolutely continuous with respect to the density of states and agrees with it in certain cases. We present a variant of a new spectral averaging result and use it to prove a pointwise upper bound on the SSF for finite-rank perturbations. | We prove that the integrated density of states (IDS) for the randomly perturbed Landau Hamiltonian is Holder continuous at all energies with any Holder expo- nent 0 < q < 1. The random Anderson-type potential is constructed with a non- negative, compactly supported single-site potential u. The distribution of the iid random variables is required to be absolutely continuous with a bounded, com- pactly supported density. This extends a previous result Combes et al. (Combes, J. M., Hislop, P. D., Klopp, F. (2003a). Holder continuity of the integrated density of states for some random operators at all energies. Int. Math. Res. Notices 2003: 179-209) that was restricted to constant magnetic fields having rational flux | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,569 |
A method is presented for the calculation of paraxial design parameters of a double-sided telecentric zoom lens with easy variation of the magnification range. The telecentric lens consists of a zoom lens with a fixed distance between focal points and a lens with a fixed focal length. The third-order aberration analysis is also performed, and spot diagrams are calculated for two f-number values. | With their constant perspective and large magnification in the working distance, double-sided telecentric lenses have been widely used in machine-vision applications. This paper puts forward a flex... | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,570 |
This paper discusses a constraint integration problem, which occurs in constructing a global view of a distributed database by local relational databases. Each local database has its own semantic constraints. such as functional, join and embedded join dependencies (FDs. JDs and EJDs, respectively). A global view of a distributed database is assumed to be defined by taking a join of these local databases. Some dependency constraints on a local database may be violated on a global view. ::: ::: In this paper, we show (a) the relationship between dependencies of local databases and dependencies appearing in a global view, (b) a testing method whether an EJD appears in a global view when only FDs and JDs are given to each local database, end (c) some conditions for a JD of a local database to appear in a global view as an EJD. | Like data, conceptual schemata change and need to be updated. If not performed with care, updates can cause problems. In this paper, we present a procedure which safely adds a fact type to a conceptual schema. This procedure, as well as being used for simple schema updates, may be applied to design and integration problems. We also present procedures for the safe removal of a fact type, and the safe elimination of redundant information from the conceptual schema. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,571 |
This paper presents the results of an air quality study conducted in a restaurant that allows smoking. Air quality data was taken in the smoking section with a conventional air distribution system in place. The air distribution system was then modified and additional data was taken. Air sample results indicate that the “air curtain” distribution system improves the effectiveness of the ventilation by reducing smoke plume drift between tables and by enhancing the natural tendency of the tobacco smoke to rise to the ceiling. The modifications to the air distribution system included replacing and relocating supply air diffusers and relocating and adding return air grilles over the smokers' tables. Small 100 mm2, 12 volt table fans were also placed on the smokers' tables. The upward air flow created by the table fans further enhanced the natural tendency of the smoke to rise toward the ceiling. Both real-time and time-averaged air samples were taken during this study. The real-time samples were taken using pa... | The flow of an air curtain mounted above a doorway in which was placed a manne- quin was studied using stereo particle image velocimetry. The study revealed that the interfer- ence of the air curtain flow was limited to a region near the doorway. The air curtain flow stag- nates around the top surfaces of the mannequin. A high level of turbulence also existed in this region. The turbulence diminished rapidly past the mannequin and increased in a thin region near the floor as the flow entered the floor vents. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,572 |
In this paper we consider the problem of optimal regulation of large space structures in the presence of flexible appendages. For simplicity of presentation, we consider a spacecraft consisting of a rigid bus and a flexible beam. The complete dynamics of the system is given by a coupled set of ordinary and partial differential equations. We show that the solution of this hybrid system is defined in a product space of appropriate finite- and infinite-dimensional spaces. We develop necessary conditions for determining the control torque and forces for optimal regulation of attitude maneuvers of the satellite along with simultaneous suppression of elastic vibrations of the flexible beam. | We present a mathematical model of a crane-trolley-load model, where the crane beam is subject to the partial differential equation (PDE) of static linear elasticity and the motion of the load is described by the dynamics of a pendulum that is fixed to a trolley moving along the crane beam. The resulting problem serves as a case study for optimal control of fully coupled partial and ordinary differential equations (ODEs). This particular type of coupled systems arises from many applications involving mechanical multi-body systems. We motivate the coupled ODE-PDE model, show its analytical well-posedness locally in time and examine the corresponding optimal control problem numerically by means of a projected gradient method with Broyden-Fletcher-Goldfarb-Shanno (BFGS) update. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,573 |
The use of computer-based numerical models to predict water circulation patterns and solute or contaminant dispersion in a water body is wellestablished in the field of coastal environmental engineering. Too often, however, such models are used without proper understanding of the parameters used in the mathematical formulation of the governing equations and the effects that varying these parameters within given ranges can have on the model results. In this paper the authors present the results of a range of parameter sensitivity tests carried out on one such numerical model, DIVAST. The sensitivity of the hydrodynamic sub-model to parameters affecting bed shear stress, eddy formation and advective acceleration is assessed and several mass conservation tests are carried out on the solute transport sub-model. The application of the model to a natural harbour on the west coast of Ireland is outlined and the results of the above tests on this model application are discussed. | This new edition of the successful undergraduate text combines fundamental theoretical concepts with design applications to provide comprehensive coverage of all the main aspects of hydraulics in civil and environmental engineering. Part I introduces the theoretical concepts essential to hydraulic engineering. Hydrostatics, hydro-dynamics, and flow in pipes and channels are all treated thoroughly. The authors then cover hydrology, sediment transport, wave theory, river and coastal engineering, and water quality modeling. This provides a broad, holistic view of the subject, enabling the reader to envisage the complexity of real problems and the design philosophies required for their solution. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,574 |
In this paper, we introduce and investigate the notions of Iω -continuous maps and Iω -irresolute maps in ideal topological spaces. Also we introduce the notions of slc*-I -sets, s -sets, λs - I -closed sets, slc* - I -continuous maps and λs - I -continuous maps. Finally, we obtain the decompositions of -continuity. | In this paper we introduce and study three different notions of generalized continuity, namely LC-irresoluteness, LC-continuity and sub-LC-continuity. All three notions are defined by using the concept of a locally closed set. A subset S of a ::: topological space X is locally closed if it is the intersection of an open and a closed set. We discuss some properties of these functions and show that a function between topological spaces is continuous if and only if it is sub-LC-continuous and nearly continuous in the sense of Ptak. Several examples are provided to illustrate the behavior of these new classes of functions. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,575 |
Evaluation of soil shear strength is an important step in the stability analysis of earth structures, foundations and natural slopes. The shear strength pro le of unsaturated soil is dictated by the suction pro le. This pro le depends on the evaporation rate, depth of the water table and the soil water retention curve. In this paper, the soil water retention curve of a dual porosity silt-bentonite mixture is determined; employing the vapor equilibrium method and osmotic suction technique, and the validity of these approaches is examined against the results from the lter paper technique. Besides, the e ect of the stress state on the suction value is studied employing the lter paper method. Furthermore, the shear strength response of the material is evaluated for a wide range of suction values (0-287MPa) employing the direct shear apparatus. Results of direct shear tests show that the expansive clay behaves like a normal consolidated soil at suction values less than, or equal to, 20.5MPa, while its behavior is similar to the heavily over consolidated soils for suction more than 20.5MPa. | In this note, a unique relationship between the effective stress parameter chi and the ratio of suction over the air entry value (suction ratio) is proposed, based on the shear strength data reported in the literature. Comparisons are made between the measured and the calculated shear strengths for two laboratory prepared unsaturated soils. Extremely good agreement has been obtained between the measured and the calculated values using the proposed relationship. (A) | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,576 |
The elastostatic problem of functionally graded circular nanobeams under torsion, with nonlocal elastic behavior proposed by E ringen , is preliminarily formulated. Exact solutions are detected for nanobeams with arbitrary axial gradations of elastic properties and radially quadratic distributions of shear moduli. Extension of the treatment to nonlocal viscoelastic composite circular nanobeams is then performed. An effective solution procedure based on L aplace transform is developed, providing a new correspondence principle in nonlocal viscoelasticity for functionally graded materials. Displacements, shear strains and stresses are established for nonlocal viscoelastic nanobeams made of periodic fiber-reinforced materials, with polymeric matrix described by a M axwell model connected in series with a V oigt model. | We apply Floquet theory of periodic coefficient second-order ODEs to an elastic waveguide. The waveguide is modeled as a uniform elastic string periodically supported by a discontinuous Winkler elastic foundation and, as a result, a Hill equation is found. The fundamental solutions, the stability regions, and the dispersion curves are determined and then plotted. An asymptotic approximation to the dispersion curve is also given. It is further shown that the end points of the band gap structure correspond to periodic and semiperiodic solutions of the Hill equation. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,577 |
Removably located within an elongated epithelium-lined tract, or tunnel, surgically formed in the subcutaneous layer of the wearer's scalp is the elongated subdermal portion of a scalp anchor. The anchor includes an external portion attachable to a hairpiece. A plurality of such anchors securely yet removably retains the hairpiece in the desired position on the scalp. | Societal value consensus has been widely discussed but rarely studied empirically. The authors developed a definition and an operational index for value consensus suitable for cross-national comparisons. They then generated and tested hypotheses concerning causal impacts of socioeconomic development and political democratization on both value importance and value consensus in a society. Data are from matched samples of teachers from 42 nations (N = 7,856) who completed a survey that measures 10 distinct types of values. Both development and democratization correlate positively with the importance of openness and self-transcendence values, and negatively with the importance of conservation and self-enhancement values. Development and democratization have opposite relations to value consensus, suppressing one another’s effects. Development increases overall value consensus, whereas democratization decreases it. Differences between effects on specific value types are discussed. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,578 |
As a good compromise between simplicity and approximation of real human vocal vold oscillation behaviour the Ishizaka-Flanagan two-mass model [1] is widely used in articulatory speech synthesis. But its poor results in modelling the oscillatory behaviour during glottal abduction/adduction and in modelling leakage flow during normal phonation are drawback. The two-mass model can be improved without increasing its complexity, if a non-oscillating and aperture-dependent bypass is added | The paper presents a numerical study about the acoustic impact of the gradual glottal opening on the production of fricatives. Sustained fricatives are simulated by using classic lumped circuit element methods to compute the propagation of the acoustic wave along the vocal tract. A recent glottis model is connected to the wave solver to simulate a partial abduction of the vocal folds during their self-oscillating cycles. Area functions of fricatives at the three places of articulation of French have been extracted from static MRI acquisitions. Simulations highlight the existence of three distinct regimes, named A, B, and C, depending on the degree of abduction of the glottis. They are characterized by the frication noise level: A exhibits a low frication noise level, B, which is a transitional unstable regime, is a mixed noise/voice signal, and C contains only frication noise. They have significant impacts on the first spectral moments. Simulations show that their boundaries depend on articulatory and glo... | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,579 |
This paper designs a security robot for public safety. The robot can be temporarily placed in a crowded place, monitoring the flow of people and assisting the public security officers to conduct effective evacuation and warning. In this paper, the structure and hardware system of the robot are introduced in detail. In view of the use scenario, the strength check and function test of wind resistant overturning stability are carried out. The robot's application can effectively improve the security work efficiency and reduce the police burden. | A key capability required by service robots operating in real-world, dynamic environments is that of Visual Intelligence, i.e., the ability to use their vision system, reasoning components and background knowledge to make sense of their environment. In this paper, we analyze the epistemic requirements for Visual Intelligence, both in a top-down fashion, using existing frameworks for human-like Visual Intelligence in the literature, and from the bottom up, based on the errors emerging from object recognition trials in a real-world robotic scenario. Finally, we use these requirements to evaluate current knowledge bases for Service Robotics and to identify gaps in the support they provide for Visual Intelligence. These gaps provide the basis of a research agenda for developing more effective knowledge representations for Visual Intelligence. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,580 |
This study examined the capital structure of listed industrial companies on Amman Stock Exchange (ASE) over the period (2001- 2005). The findings of this study contribute towards a better understanding of financing behaviour in Jordanian industrial companies. Hypotheses, based on comparing the relationships between Leverage ratio (Lev 1), LTD/TD (Long-term debts/total debts) and five explanatory variables that represent size, tangibility, profitability, long-term debt and short-term debt. To test those relationships regression analysis for Leverage ratio (Lev 1) and TD LTD | In this thesis I will research the influence of a certain set of determinants on the capital structure of Dutch stock-market listed firms. First I will select a number of firm-specific determinants as independent variables, whose influence on the capital structure I will test in multiple analyses. I will compare the influence of the firm specific variables across different time periods to capture the influence of the recent financial crisis on the relationship between the variables and the capital structure. It turns out multiple of my firm specific variables had a significant relationship, while the relationships were indeed different across the multiple selected time periods. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,581 |
Silicone rubber is a common dielectric elastomer material. Actuators made from it show excellent activate properties ::: including very large strains (up to 380%), high elastic energy densities (up to 3.4 J/g), high efficiency, high responsive ::: speed, good reliability and durability, etc. When voltage is applied on the compliant electrodes of the dielectric ::: elastomers silicone rubber, the polymer shrinks along the electric field and expands in the transverse plane. In this paper, ::: a theoretical analysis is performed on the coupling effects of the mechanical and electric fields. A nonlinear field theory ::: of deformable dielectrics and hyperelastic theory are adopted to analyze the electromechanical field behavior of these ::: actuators. Applied elastic strain energy function is obtained from the representative Yeoh model. The electric energy ::: function involves invariant and variable dielectric constant respectively. Then deduce the constitutive relation for the ::: dielectric elastomer film actuator based on the selected function. Also the mechanical behavior of the dielectric ::: elastomer silicone rubber undergoing large free deformation is studied. The constitutive modules of dielectric elastomer ::: composite under free deformation and restrained deformation are derived. The Barium Titanate (BaTiO3) with high ::: permittivity was incorporated into the raw silicone to fabricate a new dielectric elastomer, the experimental results that ::: the elastic modulus and dielectric constant were significantly improved. Finally the Yeoh model was developed to ::: characterize the elastic behavior of the new dielectric elastomer. The constitutive modules of dielectric elastomer ::: composite under free deformation and restrained deformation are derived. This is a promising analysis method for the ::: study of the coupled fields and mechanical properties of the dielectric film actuator. | Lead magnesium niobate–lead titanate (PMN–PT) ferroelectric powder was used to develop a particulated composite based on a silicone elastomer matrix, with improved dielectric permittivity. The filler was characterised by X-ray diffraction and scanning electron microscopy. Complex dielectric permittivity (10–108 Hz) and tensile mechanical properties (elastic modulus and ultimate stress) of composites at various filler contents (up to 30% by vol.) were compared with those of the neat silicone elastomer. Both the dielectric constant and loss factor regularly increased with the filler content. The elastic modulus increased with a lower rate than that of the dielectric constant. Even though the addition of filler resulted in a detriment of both toughness, ultimate stress and elongation at break, a good stretchability was still retained, as elongation ratios greater than 3 were possible at the highest filler content. Several dielectric models were compared to the experimental data and the best match was achieved by the Bruggeman model, which can be used as a predictive rule for different volume contents of filler. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,582 |
A simple idealised procedure is proposed for the analysis of individual top-antitop quark pair production and dilepton decay events, in terms of the top quark mass. This procedure is illustrated by its application to the CDF candidate event. If this event really represents top-antitop production and decay, then the top quark mass would be 131 −11 +22 GeV. | A future lepton collider, such as the proposed CLIC or ILC, would allow to study top quark properties with unprecedented precision. In this paper, we present a method to reconstruct the $t \bar{t}$ decay in the dilepton channel at future $e^+e^-$ colliders. We derive a simple, closed analytical expression for the neutrino four-momenta as a function of the $W$ boson mass and develop a maximization procedure to find the optimal solution for the reconstruction of the full $t \bar{t}$ event. We show that our method is able to reconstruct neutrino four-momenta with an error of less than $2 \, \%$ in $60 \, \%$ of the times. Finally, we test the performance of this reconstruction method in the calculation of the helicity fractions of the $W$ boson. A precise measurement of these observables could be used to probe new physics effects in the $Wtb$ vertex. We find that, from a large $t \bar{t}$ sample, our reconstruction method allows to calculate these observables with an accuracy better than $1 \, \%$. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,583 |
The nonlocalized clustering approach is generalized to 8-11Be isotopes with isospin dependent spin-orbit potential. A new form of the Tohsaki-Horiuchi-Schuck-R\"opke (THSR) wave function is introduced to provide a correct description for the {\sigma}-binding neutron in 11Be. Systematic calculations for 8-11Be isotopes are performed and results fit well with experimental values. The low energy spectrum of 11Be is also obtained, especially the correct spin-parity 1/2+ is reproduced for the intruder ground state. The exotic neutron halo structure of 11Be is studied by calculations of root-mean-square radii and density distribution. We obtain a large spatial distribution for the last valence neutron of 11Be, which fits the phenomenological extracted value from experimental data. The spectroscopic factor is also calculated and discussed for the 1/2+ ground state of 11Be. | Introduction to Magnetic Materials, 2nd Edition covers the basics of magnetic quantities, magnetic devices, and materials used in practice. While retaining much of the original, this revision now covers SQUID and alternating gradient magnetometers, magnetic force microscope, Kerr effect, amorphous alloys, rare-earth magnets, SI Units alongside cgs units, and other up-to-date topics. In addition, the authors have added an entirely new chapter on information materials. The text presents materials at the practical rather than theoretical level, allowing for a physical, quantitative, measurement-based understanding of magnetism among readers, be they professional engineers or graduate-level students. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,584 |
1 Analog, Discrete and Digital Signals.- 2 Spatio-Temporal Filtration.- 3 Discretization and Scanning.- 4 Imaging System Quality Assessment.- 5 Modulated Signals.- Appendix A: On Fundamental Notions of Probability Theory.- Appendix B: On Applications of computers in Visual Art.- References. | The MESSENGER project is supported by the NASA Discovery Program under contracts NAS5-97271 to The Johns Hopkins University Applied Physics Laboratory and NASW-00002 to the Carnegie Institution of Washington. This work was also supported by the NASA Graduate Student Research Program grant NNX09AL50H (DJG). | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | kor_Hang | 24,585 |
The advantages and economic use of vertifically corrugated steel webs in plate and box girders for steel or composite bridges are considered. Research on global and local buckling is reviewed and a design method is given, based partly on work on four recent bridges in France. Elastic stiffness in shear and ultimate strength are studied, based on finite-element analyses and laboratory tests. The tests are reported in a companion paper on flexural behaviour of plate girders with corrugated webs. (A) | This paper deals with the shear buckling strength of trapezoidally corrugated steel web, which is expected to be increasingly used at the web of hybrid girders and plate girders. Trapezoidally corrugated plates can be buckled by three different shear buckling modes: local, global, and interactive buckling mode. Different buckling strength equations are provided for each buckling mode. However, the comparison of proposed buckling formulae shows discrepancies between them, and it is suggested that some of the available formulae unconservatively predict the bucking strength. Therefore, the geometric limit condition and the equation for conservative estimation of shear buckling strength are suggested. The suggested shear buckling strength is compared with the published tests results and the results of nonlinear finite element analysis to examine the validity. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,586 |
Cenospheres prepared using fly ashes from combustion of Kuznetskii coals are investigated by Mossbauer spectroscopy, scanning electron microscopy (SEM), and thermodynamic analysis. It is shown that, in the composition range with an iron content of lower than 3.3 wt %, cenospheres involve nanosized crystalline phases, such as feldspars, ferrispinels, and pyroxenes. It is revealed that the outer and inner surfaces of the cenospheres are covered with 30- to 50-nm-thick nanofilms enriched in nanosized crystalline phases. The sizes of crystalline inclusions are estimated by etching the surface film in mineral acids with the formation of a nanosized porosity. | We studied the interrelation between the composition, morphology, and helium permeability of the shell of narrow fractions of nonmagnetic nonperforated cenospheres extracted from cenosphere concentrates of fly ash of the sialic type with the use of technological stages of hydrodynamic, magnetic separation, sizing, and aerodynamic classification. For the interval of variation of Al2O3 content from 20 to 38 wt %, the regression equation [SiO2]/[Al2O3] = 5.06 − 0.1[Al2O3] is established, with the correlation coefficient equal to −0.98. It is found that, together with the growth in the concentration of Al2O3 in the indicated interval, the content of the originally mullite phase increases from 1.3 to 42.4 wt %, and this is accompanied by the growth of the helium permeability of the glass-crystalline shell of the cenospheres. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,587 |
Programs written in distributed programming lanuages are often non-deterministac an nature and ience the execution of such programs is not only dependent upon the rogram znput, but also on the tamzng of the execution. Fhus, an attempt to monitor the runtime behavior of a non-determinist@ program through code instrumentation, such as durang debugging, can potentially alter the program’s behavior. In this paper we present techni ues for dynamzcally minimizing the intrusive e ects of monitoring by attempting to ensure deterministic events are the same for uninstrumented and instrumented programs. This goal is achieved by minimizing the intrusave effects of monitoring on message passing between processes located at different sites of a distributed system. Monitorang aclaons alter the message pool at the time of non-deterministic message selection and the order in which the messages arrive at a processor. The dynamic techniques presented in this paper minimize intrusion by restoring the message pool and message orderang. that the li f elihoods of various outcomes of the non | The concept of one event happening before another in a distributed system is examined, and is shown to define a partial ordering of the events. A distributed algorithm is given for synchronizing a system of logical clocks which can be used to totally order the events. The use of the total ordering is illustrated with a method for solving synchronization problems. The algorithm is then specialized for synchronizing physical clocks, and a bound is derived on how far out of synchrony the clocks can become. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,588 |
We consider a Gaussian parallel relay network where multiple wireless relays forward cooperatively so that a destination receives a superposition of signals propagated through multiple distinct relay paths. Previous research often assumes that the relayed signals arrive synchronously in the receiver. This is not feasible in practical wireless networks, because spatial separation causes different propagation delays for the signal components and the destination observes a multipath channel. We model the effect of signal delays by introducing spatial separation to the network geometry and present trade-off analysis between diversity, signal bandwidth, relay density, and the number of relays for both narrowband and wideband reception at the destination. | There is a certain relationship between the delay spread and the received signal strength of multipath waves. This paper describes the geometrical interpretation for spread delay in urban areas. An analytical approach for relative received power as a function of excess delay is discussed. Examples of measured data for power delay profiles are used in comparison with the analytical results. These examples show that the square of the ratio between the shortest time delay and the time delay is sufficient to approximate the power delay profile. This second order equation can also be used to calculate the time dispersive parameters of the channel such as the mean excess delay and RMS delay spread. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,589 |
Solid-state, wet-chemical and sonochemical routes of synthesis were assayed to obtain Bi 2 O 3 particles. X-Ray powder diffraction (XRD), scanning electron microscopy (SEM) and dynamic light scattering (DLS) were applied to characterize the obtained particles. Then, they were evaluated as electrode materials to develop sensor devices. The best electrochemical behavior was obtained for electrodes modified with Bi 2 O 3 particles obtained by sonochemical synthesis route. | The incorporation of nanomaterials into electrochemical sensors is an attractive approach towards the improvement of the sensitivity of amperometry and also can provide improved sensor selectivity and stability. This review (with 137 references) details the current state of the art and new trends in nanomaterial-based electrochemical sensing of hydrogen peroxide (H2O2), hydrogen sulfide (H2S) and nitric oxide (NO) in cells or released by cells. The article starts with a discussion of the significance of the three analytes, and this is followed by three sections that summarize the electrochemical detection schemes for H2O2, H2S and NO. Each section first summarizes the respective physiological roles, and then reviews electrochemical sensors based on the use of carbon nanomaterials, noble metal nanomaterials, metal oxide nanomaterials, and layered doubled hydroxides. The materials are compiled in three tables along with figures of merit for the various sensors. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,590 |
The paper explores the potential of Support Vector Machines (SVM) approach in predicting 28-day compressive strength and slump flow of self-compacting concrete. Total of 80 data collected from the exiting literature were used in present work. To compare the performance of the technique, prediction was also done using a back propagation neural network model. For this data-set, RBF kernel worked well in comparison to polynomial kernel based support vector machines and provide a root mean square error of 4.688 (MPa) (correlation coefficient | This paper proposes an extension to Gaussian process regression (GPR) for data sets composed of only a few replicated specimens and displaying a heteroscedastic behavior. Because there are several factors that are out of the control of experimenters, it is often impossible to reproduce identical specimens for a same experiment. Moreover, observations from laboratory experiments typically display a heteroscedastic interspecimen variability. Because experiments and specimen manufacturing are expensive, it is uncommon to have more than three specimens to build a model for the observed responses. The method proposed in this paper uses GPR to predict each tested specimen using a shared prior structure and models the global heteroscedastic behavior by combining observations using conjugate prior distributions. An application of the method to high-performance fiber-reinforced concrete experiments highlights fiber addition benefits for reducing water permeability caused by macrocracks. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,591 |
: A preliminary exploration of the damsite revealed foundation materials with extremely low penetration resistance. The site is in a seismic Zone 2 (Algermissen) and near the border of a seismic Zone 3. Consequently, a laboratory study was conducted to evaluate the liquefaction potential of the foundation materials when subjected to an earthquake. To evaluate the liquefaction potential, undisturbed samples of the foundation soils were obtained using a fixed-piston sampler and drilling mud. The materials were found to be fine clayey sands, fine silty sands, fine sandy clays, and silty clays. The in situ dry density was determined to range from 88 to 104 pcf in the depths considered to be critical in regard to liquefaction potential. Cyclic triaxial tests were conducted on material representative of the five depths that were anticipated to be subject to liquefaction. Based on the results of these tests, the foundation is expected to liquefy if subjected to an earthquake of magnitude 6.5 with a peak acceleration of 0.17 g or greater. Logs of borings are given in Appendix A. A simplified procedure for evaluating liquefaction potential is given in Appendix B. (Author) | An important phase of any major site investigation is the obtaining of high-quality undisturbed samples of the subsurface materials. This report describes the current state of the art in obtaining undisturbed samples of cohesionless material - specifically, sands, silts, gravels, and mixtures - primarily as it is reflected in the experience of the Waterways Experiment Station (WES) and of others on the North American continent. The report discusses general considerations in planning an undisturbed sampling programme; methods of access to the soil materials for sampling, testing, or observation; and methods of sampling cohesionless soil. Methods of access and methods of sampling are described in tables which also note the areas of applicability of the various methods, important limitations and pitfalls, and important references. It offers further discussions on special considerations in methods of sampling, such as characteristics of sampling devices, drilling fluids, and sample intervals; the care of soil samples; and evaluation of sample disturbance. It is concluded that: (a) high quality, undisturbed samples of many sands can be obtained with a fixed-piston sampler and drilling mud, with proper care and attention to details of sampling, handling, and transportation. This sampling process yields very good samples of medium dense sands, but tends to densify loose sands and loosen dense sands; (b) the use of radiographs is recommended as a nondestructive method of evaluating sample disturbance; (C) in gravels, the only proven means of recovering undisturbed samples is by hand-carving block samples; and (D) recent studies indicate that freezing in situ, followed by coring, offers a promise for obtaining undisturbed samples of much higher quality than is possible with current practice. (Author/TRRL) | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,592 |
We investigate several approaches to handle bundle dependency in a service gateway for networked appliances. We first describe the bundle dependency problem of OSGi specification and implementation and then we analyze and propose several solutions to this problem. Our discussion is around the framework initialization in JES (Java Embedded Server/sup /spl trade//), a typical implementation of OSGi specification, but the conclusions apply to other implementations, like Oscar. The advantages and disadvantages of the solutions are discussed. | Upcoming ubiquitous computing systems are required to operate in dynamic, diverse, unverified, and unpredictable operating environment. The OSGi (Open Service Gateway initiative) framework employs the service-oriented approach and the java classloader architecture for the runtime service deployment, that are well suited to the dynamic environment envisioned for home networking and ubiquitous computing. However, the current OSGi framework does not provide full reliability measures, especially for failure conditions such as network, device, and application failures. This paper analyzes software reliability issues in OSGi framework and proposes a proxy-based reliable extensions. The design concept is implemented and partly tested on an open source OSGi platform, Oscar, for the smart home residential gateway test-bed. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,593 |
At the outset the foregoing document is represented by square-wave generator using three second generation current conveyers, five resistors and one capacitor with independent control of frequency is presented. The unique features associated with such waveform generator are the easy tunability of frequency over a range of 15 Hz to 150 kHz, extremely low sensitivities as well as suitable for very large scale integration (VLSI) implementation. The working capacity of the proposed circuit is examined with the aid of SPICE models of IC AD 844 AN. Later, the circuit was built with commercially available current feedback operational amplifiers (AD 844 AN), passive components used externally and tested for waveform generation and tunability. Results achieved prove better agreement with the theoretical values. And the non-idealities also are examined. | A current mode Schmitt trigger using Current Differencing Transconductance Amplifier (CDTA) is presented in this paper. The proposed circuit employs only a single CDTA, without any passive component, that has been suitable for implementation of the IC design. The operation of the proposed Schmitt trigger circuit has been observed and enforced at a supply voltage ± 0.85 V (bias current 32 µA) using Cadence and the model parameters of a gpdk 180 nm CMOS technology. The Schmitt trigger circuit in this paper, which is realized using CDTA provides impervious to noise and insensitive to temperature. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,594 |
As a result of the moral and social conflicts surrounding abortion, workers involved in counseling potential abortion recipients are subject to certain strains. The author uses observations made at one abortion clinic to support her conclusion that these strains, as well as the methods of coping developed by staff and administration, must be considered in formulating any policy on abortion. | Two hundred and fifty-four women were followed from the second trimester of pregnancy until twelve months postpartum. Of these women, twenty-eight had had a prior therapeutic abortion and 216 women had no previous abortion. During their pregnancy and the postpartum period, the women completed a series of psychological and attitudinal measures. Analysis revealed that there were no significant differences between the two groups in terms of their demographic status, their obstetric experience or attitudes towards labour and birth. The study failed to demonstrate a relationship between anxiety during pregnancy and a prior abortion, nor were there any indications of inadequate maternal functioning. Women who had a prior abortion scored higher on the autonomy and nurturance subscales of the Personality Research Form, and had higher levels of depressive affect in the third trimester of pregnancy and in the postpartum period. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,595 |
Silicon/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) heterojunction solar cells with 16.2% efficiency and excellent stability are fabricated on pyramid-textured silicon substrates by applying a water-insoluble ester as capping layer. This shows that a conformal coating of PEDOT:PSS on textured silicon can greatly improve the junction quality with the main stability failure routes related to the moisture-induced poly(3,4-ethylenedioxythiophene) aggregations and the tunneling silicon oxide autothickening. | Solar cells, as promising devices for converting light into electricity, have a dramatically reduced performance on rainy days. Here, an energy harvesting structure that integrates a solar cell and a triboelectric nanogenerator (TENG) device is built to realize power generation from both sunlight and raindrops. A heterojunction silicon (Si) solar cell is integrated with a TENG by a mutual electrode of a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) film. Regarding the solar cell, imprinted PEDOT:PSS is used to reduce light reflection, which leads to an enhanced short-circuit current density. A single-electrode-mode water-drop TENG on the solar cell is built by combining imprinted polydimethylsiloxane (PDMS) as a triboelectric material combined with a PEDOT:PSS layer as an electrode. The increasing contact area between the imprinted PDMS and water drops greatly improves the output of the TENG with a peak short-circuit current of ∼33.0 nA and a peak open-circuit voltage of ∼2.14 V, res... | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,596 |
Synthetic aperture radar (SAR) imaging has the characteristics of acquiring remote sensing data under all weather and all time. So SAR image change detection techniques have large advantage in abruptly natural and man-made disaster. Inherent speckle noise of SAR image badly obstructs the applications for SAR image change detection. SAR image belongs to non-Gaussian distribution in general, which accords with the conditions of independent component analysis (ICA) theory. The most important benefit is that ICA and wavelet transform both can reduce speckle noise. Therefore, a new change detection algorithm based on ICA and stationary wavelet transform (ICA-SWT-CD) for multi-temporal SAR images was proposed in this paper. The merit of the algorithm is that it is insensitive to speckle noise. Finally, the practical SAR image data is performed compare experiments and the experimental results verify that the proposed algorithm is effective and feasible. | In this paper, the problem of rapid earthquake damage detection in urban areas using multitemporal synthetic aperture radar data is addressed. It is shown that the combination of intensity and phase features enhances the damage pattern extracted from the data temporal stack using a spatially aware classifier. Moreover, the use of ancillary data, easily available for urban areas, further improves the accuracy by discarding uninteresting parts of the scene and forcing homogeneous classification within city blocks to avoid "class-blurring" effects consequential to the window-based computation of relevant measures. The procedure is validated based on results for the town of Bam, Iran, and compared with ground-based survey maps | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,597 |
The investigation by Giotto of the environment of comet P/Grigg-Skjellerup has provided a large set of observations on cometary low-frequency waves for a weakly active comet, after the observations at comets P/Giacobini-Zinner and P/Halley. A large amount of waves are observed at frequencies close to the local water group ion cyclotron frequencies on the magnetic field and the plasma density in a wide region around the comet. Cross-analysis of the electron parameters with the magnetic field reveals the existence of a compressive wave component even at large distances from the nucleus. The inferred characteristics of the observed wave modes are quantitatively reproduced from a theoretical work studying the electromagnetic instabilities driven by the distribution of the newborn ions. | This tutorial summarizes our present, pre-Rosetta understanding of the basic physical processes operating in cometary environments with particular attention to cometary magnetotails. Ionization of cometary gases is responsible for most plasma processes in the magnetospheres of active comets. The interaction between the superalfvenic, magnetized solar wind and cometary ions forms a number of plasma boundaries starting with the weak bow shock and continuing with the contact surface (diamagnetic cavity boundary), the recombination layer and the inner shock. The plasma tail is sensitive to changes in the solar wind and to varying cometary activity. These processes will be explored in detail. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,598 |
High performance simulation of low energy building requires ever more accurate descriptions of the systems under study to improve the building's performance. This paper describes a numerical model to simulate a single room, using a three-dimensional description of heat conduction in the envelope with environmental conditions that vary over short time-steps are described. The simulation considers the projection of solar radiation through a window onto interior walls. The indoor air temperature is assumed to be uniform. The temperature of the inner and outer surface of the walls are calculated at each time step using a variable-step solver. Validation of the model was carried out using experimental data from a low energy cell operating in a natural climate. A set of well-calibrated temperature sensors and an infrared camera have been used to accurately measure the cell's thermal behavior. Comparison between experimental data and numerical results for free varying conditions shows good agreement and the reliability of the model is proven. These validated results were found for a highly insulated cell. Future studies for different thermal mass cells, with new materials, will be realized to show the contribution of this model. Thermal comfort will also be studied. | The aim of this paper is the numerical simulation of the sunspot area (SSA) and its location on the walls and on the floor of a room with a single window facing south. The input parameters of the calculation code are the geometry of the cell located in the site of Ksar Challala (35.1 N, 2.19 E, 800 m) in Algeria for the 21st of March, June and December. The SSA is a function of the window’s area, the date and time, the orientation of the room, the altitude and the azimuth of the sun. The obtained results show that the western wall is affected by the sun in the morning, the eastern wall in the afternoon, the floor and the north wall in the middle of the day. By increasing the window area from 1 m2 to 2 m2 we found that the SSA increases considerably. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 24,599 |
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