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how long does it take to know a dog is pregnant
|
/ 0. at 4 weeks after breeding you can take her in to your vet for an ultrasound to confirm wether or not she's pregnant. She can't get pregnant unless she was bred at the right time. her eggs wont be able to be fertilized until they are maturated 2 days after ovulation.
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how long does it take to become pregnant is a question that most couples will at some point ask. So, how long does it take to get pregnant on average? Studies say that about 50% of healthy couples will get pregnant after 4-5 months, the next 20% will get pregnant after 9 months, and for the next 15% it could take a year. Once a couple has decided to get pregnant and then learns the odds that are present, they then want to know what can they do to make the wait shorter.
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eng_Latn
| 32,800 |
how long do male dobermans grow
|
Report Abuse. Doberman's continue to grow until about 1 1/2 to 2 years old. I have a large male that was 27.5 at 12 months. He is now 29 at 1 year 5 months.
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While only male deer, elk and moose grow antlers, caribou are unique in that both males and females go through the annual process of antler growth, just at different times of year.Male caribou grow antlers during the summer, use them to compete for mates, and then shed them.ntlers begin as bony growths covered with skin and hair (velvet). They grow at incredible rates, with the immense racks of deer, elk and moose growing in just 3 to 4 months. This makes them one of the fastest growing living tissues.
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eng_Latn
| 32,801 |
how many days dog is in gestation
|
The Gestation Period for Dogs is approximately 59-65 days from the first breeding. Dogs will not always conceive after one breeding and will generally mate multiple times in one cycle. The Dog Gestation Period Calculator above attempts to generalize the estimation of the due date without any additional factors using a 62 day gestation period for dogs.
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After breeding, a female dog has a gestation time that can last anywhere from 55 to 66 days. After the 40th day, her breasts will enlarge noticeably and she will begin to put on weight.
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eng_Latn
| 32,802 |
Could I simply use elephant cells and an artificial uterus to clone elephants?
|
If we left earth, would we just need to bring elephant sperm, elephant cells and an artificial elephant uterus to clone elephants?
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With advancement in technology, why doesn't NASA plan to build a cheaper to operate space shuttle?
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eng_Latn
| 32,803 |
how soon will humans be cloned
|
I don't think I said that ... I predicted that human cloning would be with us in 10 years and I still believe that is the case, because there is a demand among a small number of people for this technology to have babies. It's being driven by the marketplace.
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1 The first cloned mammal successfully produced using a cell taken from another animal was âDolly the sheepâ - born in 1996. 2 The growing list of species to have now been cloned includes mice, pigs, goats, dogs, cats, horses and mules. 3 Fewer than five per cent of cloned embryos usually survive to birth. Read our submission to the European Food Safety Authority (on behalf of Eurogroup for Animals): The impact of cloning on animal welfare (2008) (PDF 50.4KB) . 2 See our submission to the UK Food Standards Agency: Cloning animals for food (2008) (PDF 108KB) .
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eng_Latn
| 32,804 |
Low Dose Rate Test Results for National Semiconductor's ELDRS-Free LM136-2.5 Bipolar Reference
|
Continuing evaluation of bipolar linear devices for total dose dependency and ELDRS effects
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Continuing evaluation of bipolar linear devices for total dose dependency and ELDRS effects
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eng_Latn
| 32,805 |
Design of a CAN interface for custom circuits
|
This paper presents the experience of the development of a CAN interface to be integrated in custom circuits (ASICs, FPGAs). The CAN controller has been designed in VHDL, so it can be targeted to different implementation technologies. The design method of the block is also presented in the paper as an experience of how to easily design digital systems to be reused in different applications, assuring its quality and reliability.
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The small signal behavior of a frequency controlled resonant converter is modeled as an equivalent PWM converter. By this model, a recently developed simulation algorithm for PWM converter is modified to simulate the open loop small signal behavior. PSPICE simulation results show that this approach is accurate and efficient.
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eng_Latn
| 32,806 |
A new double model controller with fuzzy switching based-on FUZZY rules
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Design of Hierarchical Fuzzy PID Controller Based on Granular Computing in LabVIEW
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Performance Analysis of A PI Controller and AFuzzy Controller for Single Phase Shunt ActivePower Filter
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eng_Latn
| 32,807 |
On the practical implementation of non-integer order filters
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Application of reduced models of non-integer order integrator to the realization of PIλD controller
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Class numbers of orders in cubic fields
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eng_Latn
| 32,808 |
A control approach for detecting source current and series active power filter
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A new approach to harmonic compensation in power system-a combined system of series active and shunt passive filters
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Hybrid Position and Force Control without Force Sensor
|
eng_Latn
| 32,809 |
A computer study of self-tuning PID digital voltage regulator for a synchronous generator is presented. The regulator is simple and can handle regular load changes as well as severe disturbances in the power system. The algorithm for the proposed regulator combines a least-squares estimator with a digital PID control algorithm. The parameters of the PID control algorithm are dynamically changed according to the estimated model. A second control strategy comprising a dynamic variation of the weighting coefficients of the main and stabilizing feedback signals is also described. The influence of the PID regulator with one of the two control strategies applied at a time, and with the two of them simultaneously applied are examined for various disturbances. Compared to a conventional continuous acting voltage regulator, the proposed regulator improves the transient performance of the synchronous machine.
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The main concepts of the application of digital controllers to a power system as automatic voltage regulators are presented in this paper. An experimental study using a physical model of a limited size power system has been performed and described. The synchronous generator model in this study was equipped with a microprocessor based automatic voltage regulator. The control algorithm depends on a real proportional-plus integral-plus derivative scheme which is generally accepted as an efficient and reliable controller. The feedback signals to the controller are obtained as samples of the terminal voltage of the generator (as the main feedback signal) and the shaft speed (as the stabilizing signal). The second method was developed by applying an algorithm which computes on-line the weighting coefficients to the variances of the corresponding output variables. According to this strategy the weights are allowed to vary dynamically over all the range. A third scheme which depends on the same technique but assigns constant offset values to the weighting coefficients has been tested as well. The test results are presented in the paper. The experimental model and technique are also documented in the paper.
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A multivariable self-tuning PID (SPID) controller is introduced to robot manipulator control. The control structure is simple, eliminates interactions quite well, and is easy to implement.
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eng_Latn
| 32,810 |
This article explores a novel fuzzy logic controller (FLC) based threephase shunt active power line conditioners (APLC) for power quality improvements due to the non-linear loads. The fuzzy logic controller is Mamdani-type and linguistic description, so it does not necessitate a mathematical model of the system. The FLC controller is capable of controlling harmonic current and dc-side capacitor voltage of the inverter to improve the performance of the active power filter. Hysteresis current controller (HCC) is used to generate the switching signals from the comparison of reference current and actual current for driving the current controlled voltage source inverter (VSI). Extensive simulation executed and tested under different non-linear load conditions. The simulation results reveal that the APLC with fuzzy logic controller is a perfect candidate for current harmonics and reactive power compensation.
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This paper presents a PI, PID and Fuzzy Logic Controller (FLC) based shunt active filter for power line conditioners (PLC) to improve the power quality in the distribution network. This active power filter is implemented with current controlled cascaded multilevel voltage source inverter (VSI). It is connected at the point of common coupling for compensating harmonic and reactive power by injecting equal but opposite harmonic compensating currents. The reference current extraction is based on sensing main currents only, which require current harmonics and reactive volt-ampere compensation. The PI or PID or fuzzy logic controller is used to estimates the peak reference current by controlling the dc-bus capacitor voltage of the cascaded inverter. The cascaded multilevel inverter switching signals are derivates from triangular-sampling current controller; it gives a good dynamic performance under steady state and transient operations. The cascaded active filter system is validated through extensive simulation under steady state and transient conditions with different non-linear loads. These simulation results have been revealed that the cascaded active power filter performs perfectly in conjunction with PI or PID or FLC. A comparative assessment of these three different controllers is disclosed.
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Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights.
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eng_Latn
| 32,811 |
This paper presents a complete and integrated environment for rapid prototyping of robust proportional-integral-derivative (PID) fuzzy controller that allows rapid realization of novel designs. The architecture of the proposed controller is basically composed of three independent fuzzy sub-controllers. Then, the three sub-controllers are combined together to form the overall fuzzy PID controller. The design strategy incorporates a fuzzy tuner for realizing a guaranteed-PID performance fuzzy controller that can assist practitioner to achieve the best control design for the entire operating envelop. The design, analysis, and implementation stages are carried out entirely using a dSPACE DS1104 digital signal processor (DSP)-based real-time data acquisition control (DAC) system, and MATLAB/Simulink environment. Experimental results show that the proposed fuzzy PID controller produces superior control performance than the conventional PID controllers, particularly in handling nonlinearities and external disturbances
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A fuzzy proportional-integral-derivative (PID) controller is designed using time-delay estimation (TDE). In this paper, we show that, in a discrete-time domain, the fuzzy PID controller is a superset of a time-delay controller (TDC). In other words, with certain fuzzy parameter conditions, the discrete fuzzy PID controller is equivalent to the discrete TDC. Tuning the fuzzy PID controller can be started by exploiting the TDC: a simple, efficient and effective controller. The initial fuzzy parameters can be obtained with equivalence relationships between the fuzzy PID controller and the TDC. Furthermore, the performance of the fuzzy PID controller can be enhanced by using the non-linear control surface described by various fuzzy parameters. To this end, a fuzzy TDC is proposed using the TDE and the desired fuzzy error dynamics, and a conversion formula from the fuzzy TDC to the fuzzy PID controller is derived in a discrete-time domain. The effectiveness of the proposed method is verified through experiment...
|
A fuzzy proportional-integral-derivative (PID) controller is designed using time-delay estimation (TDE). In this paper, we show that, in a discrete-time domain, the fuzzy PID controller is a superset of a time-delay controller (TDC). In other words, with certain fuzzy parameter conditions, the discrete fuzzy PID controller is equivalent to the discrete TDC. Tuning the fuzzy PID controller can be started by exploiting the TDC: a simple, efficient and effective controller. The initial fuzzy parameters can be obtained with equivalence relationships between the fuzzy PID controller and the TDC. Furthermore, the performance of the fuzzy PID controller can be enhanced by using the non-linear control surface described by various fuzzy parameters. To this end, a fuzzy TDC is proposed using the TDE and the desired fuzzy error dynamics, and a conversion formula from the fuzzy TDC to the fuzzy PID controller is derived in a discrete-time domain. The effectiveness of the proposed method is verified through experiment...
|
eng_Latn
| 32,812 |
Optimum control is concerned with operating a dynamic system at minimum cost, which means that the settings of a controller governing a process are found by using a mathematical algorithm that minimizes a cost function with weighting factors supplied. The 'cost' function is frequently defined as the sum of the deviations of key measurements from their desired values. The Linear Quadratic Regulator (LQR) finds the controller settings that minimize the undesired deviations. The choice of the weighting factors is made through trial and error. In this paper, a genetic algorithm is utilised to determine the optimum weighting matrices for a LQR. The process used as the investigation tool is a binary distillation column which possesses multivariable and nonlinear features. Simulation results show the effectiveness of the proposed approach.
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A state-of-the-art study of computerized control of chemical processes used in industry, this book is for chemical engineering and industrial chemistry students involved in learning the micro-macro design of chemical process systems.
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This project is focused mainly on designing and implementing Linear Quadratic Regulator (LQR) controller and PID controller for a Dc servo motor. The PID and LQR controller are used to control the speed and position of the Dc servo motor, with a specified performance requirement. To ensure that the controller satisfies the requirement, simulation using MATLAB/Simulink software will be performed to obtain the optimum PID and LQR controller parameters. The obtained parameters are then used to implement LQR controller to the real Dc servo motor. The performance of the LQR controller will then be compared with that of PID controller.
|
eng_Latn
| 32,813 |
DC-DC converters can be found in almost every power electronics device. To improve the efficiency and controller response of a DC-DC converter to dynamical system changes, neural network has been chosen as an alternative to classic methods. However, no prior work has been done in the neural network approach for control of a PSFB (phase-shifted full-bridge) converter yet. In this research, a multi-layer feedforward neural network controller is proposed. The neural network based controller has the advantage of adaptive learning ability, and can work under the situation when the input voltage and load current fluctuate. Levenberg-Marquardt back-propagation training algorithm is used in computer simulation. The neural controller is then implemented on hardware using a DSP (digital signal processor). Satisfactory experimental results are obtained.
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This paper addresses the problem of deadbeat control in fully controlled high-power factor rectifiers. Improved deadbeat control can be achieved through the use of neural network-based predictors for the input current reference to the rectifier. In this application, online training is absolutely required. In order to achieve sufficiently fast online training, a new random search algorithm is presented and evaluated. Simulation results show that this type of network training yields equivalent performance to standard backpropagation training. Unlike backpropagation, however, the random weight change method can be implemented in mixed digital/analog hardware for this application. The paper proposes a very large-scale integration implementation which achieves a training epoch as low as 8 /spl mu/s.
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Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights.
|
eng_Latn
| 32,814 |
This paper investigates the issue of performance optimization for proton exchange membrane fuel cell (PEMFC) system. In PEMFC system, the system efficiency is the key parameters to evaluate the system performance which is sensitive to the air flow rate. Thus, the careful selection of the air flow rate is crucial to ensure efficient, reliable and durable operation of the PEMFC system. In this paper, the dynamic response of the system under variable air flow rate is studied in detail by means of experiments on the built 5 kW PEMFC system with 110 cells and a catalyst active area of 250 cm2. The oxygen excess ratio (OER) is defined to indicate the state of oxygen supply. The experimental results show that the maximum efficiency is existed under certain net current. The OER conditions have the optimal characteristic for system efficiency. Through the optimization of system performance, the system efficiency can be increased by 12.2% on average. At the same time, the system dynamic characteristic under oxygen starvation and oxygen saturation are analyzed in detail based on the experimental data.
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Increasing in the net output power of proton-exchange membrane fuel cell (PEMFC) systems is an important aspect of improving the performance of PEMFC. In order to enhance the net output power of the PEMFC system, the maximum net power strategy of the PEMFC system is proposed. Since the PEMFC system is a nonlinear system with time delay and uncertainty, sliding mode variable structure control (SMVSC) based on the exponential approach law is applied to achieve real-time operation at the maximum net PowerPoint. This article has two main contributions. The first major contribution of this article is to obtain the maximum net power surface of the PEMFC by multivariate fitting and to design the maximum net power regulator. The second major contribution of this article is to design a sliding mode variable structure based on the exponential approach law. The Lyapunov function is used to converge the sliding mode surface to the defined neighborhood. The advantage of this structural design is that the approach speed is gradually reduced from a larger value, and the response time is shortened. The control effect of the maximum net power strategy based on SMVSC is verified by the PEMFC experimental platform.
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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.
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eng_Latn
| 32,815 |
Defined deletion mutants of Escherichia coli defective for the synthesis of pyruvate formate-lyase (PFL) or pyruvate dehydrogenase (PDH) were analysed in regards their growth in batch culture and their enzyme levels under fermentative and nitrate respiratory conditions. A pfl mutant proved not to be completely auxotrophic for acetate when grown anaerobically in glucose minimal medium. In contrast, a pfl aceEF double mutant exhibited an absolute requirement for acetate, indicating that PDH is the source of acetyl-CoA in the pfl mutant. Growth of both pfl and aceEF single mutants under nitrate respiratory conditions was essentially indistinguishable from the wild-type. Thus, either PFL or PDH can be used to catabolize pyruvate in nitrate-respiring cells. The activities of PFL and PDH measured after growth with nitrate are commensurate with this proposal.
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FocA belongs to the formate-nitrate transporter family and plays an essential role in the export and uptake of formate in organisms. According to the available crystal structures, the N-terminal residues of FocA are structurally featureless at physiological conditions but at reduced pH form helices to harbor the cytoplasmic entrance of the substrate permeation pathway, which apparently explains the cessation of electrical signal observed in electrophysiological experiments. In this work, we found by structural analysis and molecular dynamics simulations that those N-terminal helices cannot effectively preclude the substrate permeation. Equilibrium simulations and thermodynamic calculations suggest that FocA is permeable to both formate and formic acid, the latter of which is transparent to electrophysiological studies as an electrically neutral species. Hence, the cease of electrical current at acidic pH may be caused by the change of the transported substrate from formate to formic acid. In addition, the mechanism of formate export at physiological pH is discussed.
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The cooling storage ring of the heavy ion research facility in Lanzhou (HIRFL-CSR) is one of the five mega-science projects undertaken by Chinese Academy of Science within its ninth and tenth five-year plan period. The HIRFL-CSR facility can providing heavy ion beams in wide energy range, manifold and with high quality. This paper presents a hybrid filter structure consisting of a passive filter and a parallel dc active power filter (DCAPF) for a sample magnet power supply in HIRFL-CSR. The configuration of the power system with the DCAPF is introduced. Then a novel feedback control scheme for the DCAPF is proposed with detecting the output ripple voltage across the magnet load. For detailed discussion, a simple model of the whole system has been derived and the stability characteristic is analyzed. Through simulation and experiment investigation, the DCAPF is successfully applied in a 120-kW magnet power supply in HIRFL-CSR finally. The ripple factor and tracking accuracy of the output current through the load achieve 8.87 ppm and 100 ppm, respectively. Therefore, the rigor requirements of low output current ripple and fast ramp rate are both satisfied with the DCAPF proposed.
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eng_Latn
| 32,816 |
Adaptive hysteresis and fuzzy logic controlled-based shunt active power filter resistant to shoot-through phenomenon
|
Modified Synchronous Reference Frame Based Shunt Active Power Filter with Fuzzy Logic Control Pulse Width Modulation Inverter
|
Performance Analysis of A PI Controller and AFuzzy Controller for Single Phase Shunt ActivePower Filter
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eng_Latn
| 32,817 |
The paper analyzed the defects and causes of shunt APF and serial APF when they are used to suppress the distortion in load current or in source voltage separately. It also introduced the operation principle of unified power quality compensator (UPQC), which is able to compensate for both the source voltage and load current at the same time. The paper proposed the reference criteria comparison detection method for voltage distortion, dq0 detection method for current distortion and PI control strategy for stabilizing the voltage of DC capacitors. Simulation result verified the correctness of analysis and the effectiveness of UPQC design.
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A new, substantial improvement of the hysteresis current control method for voltage source power converters is presented. A simple and fast prediction of the hysteresis band is added to a linearized version of the phase-locked-loop control, thus ensuring constant switching frequency and tight control of the position of modulation pulses. This allows high accuracy in tracking highly distorted current waveforms, and minimizes the ripple in multi-phase systems. The technique implementation is very simple and robust, employing only a small number of conventional, inexpensive analog and logic components. It does not require trimmings or tunings, giving the control the capability to adjust itself to the different operating conditions. The proposed method is compared with the most diffused modulation techniques, demonstrating its superior performance in responding to the most demanding conditions met in active filters. The behaviour of the method has been fully verified by simulation and by experimental tests.
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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.
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eng_Latn
| 32,818 |
In this paper, the finite-difference time-domain (FDTD) technique is used for the full wave analysis of picosecond and subpicosecond photoconductive switches. By applying a novel voltage source formulation and the lumped-element technique, pulse generation through single switching unit in a transmission line and switches in different pulse-forming networks are simulated using the FDTD model. The simulation results agree well with the theoretical analysis and experimental data. The effects of the dispersion of the transmission line and the pulse-forming networks on ultrashort pulse formation are also studied using the FDTD simulation model.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
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The finite-difference-time-domain (FDTD) method is extended to include distributed electromagnetic systems with lumped elements (a hybrid system) and voltage and current sources. FDTD equations that include nonlinear elements like diodes and transistors are derived. Calculation of driving-point impedance is described. Comparison of FDTD calculated results with analytical results for several two-dimensional transmission-line configurations illustrates the accuracy of the method. FDTD results for a transistor model and a diode are compared with SPICE calculations. The extended FDTD method should prove useful in the design and analysis of complicated distributed systems with various active, passive, linear, and nonlinear lumped electrical components. >
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The finite-difference-time-domain (FDTD) method is extended to include distributed electromagnetic systems with lumped elements (a hybrid system) and voltage and current sources. FDTD equations that include nonlinear elements like diodes and transistors are derived. Calculation of driving-point impedance is described. Comparison of FDTD calculated results with analytical results for several two-dimensional transmission-line configurations illustrates the accuracy of the method. FDTD results for a transistor model and a diode are compared with SPICE calculations. The extended FDTD method should prove useful in the design and analysis of complicated distributed systems with various active, passive, linear, and nonlinear lumped electrical components. >
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eng_Latn
| 32,819 |
A novel digital frequency tuning technique is presented for integrated active RC filters. Instead of varying the values of the capacitors or resistors as in traditional approaches, the proposed technique achieves frequency tuning by dividing the currents that flow from resistors to virtual grounds. Current division is performed through a digitally programmable current division network added at each virtual ground. The technique features compact size, wide tuning range and high linearity. Transistor level simulation results are presented to demonstrate the technique.
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A near-infrared heart-rate measurement IC that processes the photoplethysmographic signal was designed using a 0.35-/spl mu/m CMOS technology. The IC consists of a current-to-voltage (I-V) converter, a buffer, a sample-and-hold circuit, a second-order continuous-time low-pass filter (CT-LPF), a comparator, and a timing circuit that is used to pulse the external light-emitting diode with a very low duty cycle to reduce its power consumption. The current steering technique is employed in the design of the CT-LPF to meet the requirement for very low cutoff frequency. The circuit operates from a 3-V lithium battery, occupies a core area of 0.46 mm/sup 2/ and has a power consumption of 4.5 mW. The measurement results corroborate with simulation results and show that the CT-LPF can achieve a cutoff frequency of as low as 0.25 Hz. This demonstrates the feasibility of current steering technique in the design of filter for low-frequency application.
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Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights.
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eng_Latn
| 32,820 |
The high-field quasi-continuous magnets (QCM) are of great interest for scientific experiments that require long pulse duration and in particular a field pulse with a flat-top. For the QCM, the power supply is a real challenge. At the Wuhan National High Magnetic Field Center (WHMFC), it is planned to realize a 45 T/500 ms flat-top field by the series combination of a 0.6 kV/35 kA battery bank and a 12-pulse rectifier that is powered by a 100 MVA/100 MJ flywheel pulse generator (FPG). In order to reduce the dc current ripple, a dc passive filter is connected in parallel with the rectifier. The simulation of the pulse shape with respect to the voltage profile supplied by the power supply takes the resistance of the magnet into account; this increases with temperature as a function of coil current. The configuration and the associated control strategy are presented in this paper. A simulation model of the combined power supply system is developed and compared with the model of a single rectifier supply system. Results are provided to validate the proposed method.
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The majority of high-current dc power supplies for beam bending magnets have well known LCR low-pass ripple filters. To avoid prohibitive heat losses, the filter damping resistor is in series with the capacitor and not in the dc path. Such filters, when critically damped, attenuate high frequencies by 6 dB/octave. This paper analyzes an improved underdamped LCR filter which attenuates high frequencies by 12 dB/octave. Depending on the application, the improved filter can be designed to have an oscillatory or a non-oscillatory response to a step change of the input voltage. Design curves are given which show the frequency response and the time response to a unit step of a normalized improved filter for various degrees of damping.
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Perfect Quantum Cloning Machines (QCM) would allow to use quantum nonlocality for arbitrary fast signaling. However perfect QCM cannot exist. We derive a bound on the fidelity of QCM compatible with the no-signaling constraint. This bound equals the fidelity of the Bu\v{z}ek-Hillery QCM.
|
eng_Latn
| 32,821 |
Various electronic circuits such as inverters, choppers, cyclo-converters, SMPS used by industrial and domestic purposes are non-linear in nature, which makes the load current to be distorted, causing undesirable effects like heating, equipment damages, EMI related problems in power system. The active power filter (APF) is the best solution for eliminating the harmonics caused by the non-linear loads. This paper presents about a three-phase four-wire active power filter for power line conditioning to improve power quality in the distribution network and implementation of a digitally controlled APF. The active power filter is implemented with PWM based current controlled voltage source inverter (VSI).The switching signals for APF are generated through proposed three-level hysteresis current controller (HCC). The shunt APF system is modeled and investigated under different unbalanced non-linear load conditions using MATLAB program. The Controller Design using Hardware Description Language (VHDL or VERILOG) becomes independent of process technology. Synchronous reference frame (SRF) is used for generation of reference current. Both PI current algorithm and HCC are written in VHDL code and implemented using FPGA platform.
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In this paper a novel hysteresis current control for active power filter (APF) is suggested which is based on optimal voltage vector and in the meantime with constant switching frequency. In the method the location region of the reference voltage vector is detected quickly by a set of hysteresis comparators through one try-and-error process. Two appropriate switches are then selected to control the corresponding two line-to-line currents independently with constant switching frequency. The new method has the advantages of fast allocation of reference voltage space vector, good current tracking accuracy, and constant switching frequency. Therefore, it is efficient and safe in operation. Computer simulation results show that the new current control method can improve APF performance noticeably.
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With the wide application of power electronic devices, especially the use of non-linear device, a large number of harmonics and reactive current injected into the grid, which will cause power grid pollution, and the power quality problems have become increasingly serious .Active Power Filter (APF) is an important device for the power system harmonics and reactive power compensating. The real-time control and accuracy is a key to achieving effective compensation. Several suitable for active power filters basic principle of the compensation current control strategy is introduced in this paper, the paper carries on the contrast analysis, and points out the advantages and disadvantages of each, The development of the control strategy of the active filter can achieve a better performance and a wider range of application.
|
eng_Latn
| 32,822 |
Cardiac models constructed from sets of differential equations provide invaluable information about heart mechanism and disorder of both human and animals. As tuning the parameters is a profoundly important step of modeling, this paper presents a novel parametrization technique based on a bilevel framework that benefits from two solution approaches, namely mixed integer genetic algorithm (MIGA) and linear least squares (LLS). In the upper-level optimization step, the action potential (AP) of the model is fitted to the reference AP using MIGA. In the lower-level optimization step, the mismatch between the total current of the model and reference is minimized via a clamp concept-based linearization and LLS solution approach. Notably, the clamp concept can diminish the nonlinearity of the parameter fitting problem. The issue of dependency on initial parameters in the lower-level problem, as well as the sensitivity of model parameters to linearization, are circumvented by MIGA in the upper-level optimization. For evaluation of MIGA-LLS performance, two complex human ventricular models are employed. The results demonstrate that in comparison to the genetic algorithm (GA)-based approach, the proposed framework significantly reduces the average and variation of normalized root-mean-squared error (NRMSE) in terms of the AP and total current in different trials. Variability in the resulting parameter values is considerably decreased as well.
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We examine the problem of parameter estimation in mathematical models of excitable cell cardiac electrical activity using the well-known Beeler-Reuter (1977) ionic equations for the ventricular action potential. The estimation problem can be regarded as equivalent to the accurate reconstruction of ionic current kinetics and amplitudes in an excitable cell model, given only action potential experimental data. We show that in the Beeler-Reuter case, all ionic currents may be reasonably reconstructed using an experimental design consisting of action potential recordings perturbed by pseudo-random injection currents. The Beeler-Reuter model was parameterised into 63 parameters completely defining all membrane current amplitudes and kinetics. Total membrane current was fitted to model-generated experimental data using a 'data-clamp' protocol. The experimental data consisted of a default action-potential waveform and an optional series of perturbed waveforms generated by current injections. Local parameter identifiability was ascertained from the reciprocal condition value (1/lambda) of the Hessian at the known solution. When fitting to a single action potential waveform, the model was found to be over-determined, having a 1/lambda value of approximately 3.6e-14. This value improved slightly to approximately 1.4e-10 when an additional 2 perturbed waveforms were included in the fitting process, suggesting that the additional data did not overly improve the identifiability problem. The additional data, however, did allow the accurate reconstruction of all ionic currents. This indicates that by appropriate experimental design, it may be possible to infer the properties of underlying membrane currents from observation of transmembrane potential waveforms perturbed by pseudo-random currents.
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This paper presents an efficient real-coded mixed-integer genetic algorithm (MIGA) for solving non-convex optimal power flow (OPF) problems with considering transmission security and bus voltage constraints for practical application. In the MIGA method, the individual is the real-coded representation that contains a mixture of continuous and discrete control variables, and two arithmetic crossover and mutation schemes are proposed to deal with continuous/discrete control variables, respectively. The objective of OPF is defined that not only to minimize total generation cost but also to enhance transmission security, to reduce transmission loss, to improve the bus voltage profile under normal or contingent states. Moreover, the valve-point loading effect of thermal units should be taken into consideration. The effectiveness of the proposed method is demonstrated for a 26-bus and the IEEE 57-bus systems, and it is compared with the evolutionary programming (EP) in terms of solution quality and evolutionary computing efficiency. The experimental results show that the MIGA-based OPF method is superior to the EP.
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eng_Latn
| 32,823 |
The nonlinearity and time varying characteristics of pH neutralization is a highly challenging control in the chemical process industries. In this paper, a real time pH neutralization process is studied by using Bacterial Foraging optimization (BFO) based PI controller. The real time pH neutralization process is represented in First Order plus Dead Time (FOPDT) Model. The controller parameters such as p K the model using BFO optimization technique and its results are validated against Ziegler and Nichols (ZN) Method and Genetic Algorithm based optimization techniques. The performance of the processes are carried out in the simulation environment and also implemented on LabVIEW based real time pH process. The results indicate that the Bacterial Foraging optimization (BFO) Algorithm based PI controller has faster settling time, better set point tracking and high disturbance rejection for the pH neutralization process. Keywords: pH, PI Controller, Optimization, Ziegler and Nichols (ZN) Method, Genetic Algorithm (GA) and Bacterial Foraging Algorithm optimization (BFO).
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The article presents a design and implementation of decentralized Proportional Integral (PI) controller with decoupler based on Smith Predictor for a Batch Distillation Column. Decoupler is used to minimize the interaction combining it with decentralized control algorithm. To minimize the loop interaction between the loops, an ideal decoupling technique is implemented on a First Order Plus Dead Time (FOPDT) model. The PI controller is designed ::: using Smith Predictor method. The simulation of Smith ::: Predictor technique has been adopted to study the main ::: effect and the interaction effect of the Batch Distillation ::: Column. The controller is designed and implemented ::: on a Batch Distillation Column.
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Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights.
|
eng_Latn
| 32,824 |
This paper introduces a rather simple but effective procedure for short-time stability analysis of linear dynamical systems. Useful information regarding short-time stability are obtained from time domain analysis of "eigenvalues". It is observed that a system which is ruled out to be unstable can still be stable for a short time or a system which is said to be stable might be just short-time stable. Examples are given to demonstrate the capability of the procedure. >
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In the paper an approximate model of time-varying linear systems using a sequence of time-invariant systems is suggested. The conditions for validity of the approximation are proven with a theorem. Examples comparing the numerical solution of the original system and the analytical solution of the model are given. For the system under the consideration a new criterion giving sufficient conditions for robust Lagrange stability is suggested. The criterion is proven with a theorem. Examples are given showing stable and non stable solutions of a time-varying system and the results are compared with the numerical Runge-Kutta solution of the system
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This paper presents the application of wavelet transforms in power system transient and harmonic analyses. Based on the discrete time domain approximation, the system components such as resistors, inductors and capacitor are modeled respectively in the discrete wavelet domain for the purpose of transient and steady state analyses. Since the power system is described by a set of ordinary differential equations, an initial value of the state variable is considered for the transient analysis, while a periodic condition is applied to the state variable for the steady state analysis. The wavelet domain impedance is set up, and the equivalent circuit is thus built for system simulation. This method can be implemented by any kind of orthogonal wavelet transform. Numerical results from an arc furnace system are also presented for the transient, harmonic and time-frequency analyses.
|
eng_Latn
| 32,825 |
A wide-range-input AC/DC converter for FADEC system application
|
According to the output characteristics of the special generator for full authority digital electronic control(FADEC)system of aero-engine,a constant current variable frequency control AC/DC(alternating current/direct current)transform technique based on current feedback was proposed with purpose of accommodating to the wide-range-output of the special generator,so as to meet the power supply requirements of FADEC system.The control strategy,topological structure and operation principles were embodied along with the overvoltage test and protection design.Experiments results prove the reliability of the converter in full temperature range from-55℃to 125℃,and compliance with the stipulations of national military standard GJB181 Acovering aircraft electric power characteristics.Research findings has been successfully applied in certain aero-engine numerical control system and validated in both bench test and flight platform experiment.
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This paper presents SC-FDE implementation in HF communication.We introduce the basic theory of SC-FDE,and analyze the problems of PAR,frequency shift,computation complexity about SC-FDE.At last,we simulate the performance of SC-FDE in HF channel.The study shows that SC-FDE is a HF waveform design method equivalent to OFDM and has good future.
|
eng_Latn
| 32,826 |
Method and equipment for avoiding RIP loop circuit in CE dual-homing network
|
The invention discloses a method for avoiding RIP loop circuit in a CE dual-homing network, comprising the following steps: configuring CE dual-homing PE with addition and analysis functions of an AS number, acquiring the AS number carried in RIP message according to previous configuration when RIP route is introduced into BGP, and comparing the AS number with a local AS number; and discarding the RIP message when the AS number is the same with the local AS number, thereby avoiding loop circuit message occurred between the CE and the two PE connected with CE when RIP route and BGP route are mutually introduced in the CE dual-homing network.
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A description of how accurate system modelling of a dc system with an electromagnetic transient simulation program can be used to study and correct interbipole oscillations between converters connected into a parallel multiterminal system is given. The paper shows how to decide on the detail of modelling that is required, and demonstrates that it is often not enough to use prepackaged , generic HVDC control models, supplied with these programs. The detail of control models that are used in the electromagnetic simulation programs are shown to have a significant impact, in some cases, on the simulation results. In particular, a case of six hertz oscillations, in the dc currents of two converters on the Nelson River System, is accurately simulated, and it is shown that control modifications suggested by the simulation actually do eliminate the interbipole oscillations.
|
eng_Latn
| 32,827 |
The Research of PWM Rectifier Unbalanced Power Supply and DSP Implementation
|
1 Peng Yanqing, 2 Zhang Ji, 3 Fu Xiao, 4 Wen Qianwen, 5 Chen Zhenshan *1 Department of Electronic and Electrical Engineering, Xiamen University of Technology, Xiamen 361024, China, [email protected] 2 Department of Electronic and Electrical Engineering, Xiamen University of Technology, Xiamen 361024, China, [email protected] 3 School of Information and Electrical Engineering, China University of Mining and Technology, Xuzhou 221116, [email protected] 4 Department of Automation, Xiamen University, Xiamen 361005, China, [email protected] Department of Automation, Xiamen University, Xiamen 361005, China, [email protected] doi : 10.4156/jcit.vol6.issue7.16
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The design of an amplitude selector with well-defined discrimination thresholds for rapid pulses is described. The minimum resolution time is l mu sec, and the stability is very good. The circuit is utilized with proportional and scintillation counters. (J.S.R.)
|
eng_Latn
| 32,828 |
Partial Characterization of Alkaline Phosphatase in Some Species of Fresh Water Cichlids ('Wesafu', Oreochromis niloticus and Sarotherodon melanotheron)
|
Alkaline phosphatases (APs) are homodimeric enzymes that catalyze the hydrolysis and transphosphorylation of phosphate monoesters. Alkaline phosphatase activity was determined in different tissue homogenates (gills, stomach, muscle and bones) of species of Cichlid fish (Tilapia): Wesafu, Oreochromis niloticus and Sarotherodon melanotheron. The bone was found to have the highest activity of alkaline phosphatase. The Km and Vmax values for the fish bone alkaline phosphatase (FBAP) were estimated to be 16.0 M and 0.903 µmol/min/mol for Wesafu, 4.0 M and 1.94 µmol/min/mol for O. niloticus and 11.0 M and 2.237 µmol/min/mol for S. melanotheron respectively. The pH optimum of the enzyme for the categories of fishes was estimated to be 9. Divalent metals such as Mg 2+ and Ca 2+ enhanced enzyme activity but have an inhibitory effect at concentration above 1.0 mM. The highest activities of the enzyme in the bone of the three species of fishes in this study are similar to what have been reported in some vertebrates.
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0B Abstract- This paper presents a control method of the input DC voltages of three-level Neutral Point Clamped (NPC) autonomous shunt Active Power Filter (APF), which is applied to eliminate line current harmonics and compensate reactive power. In the first part, the authors present a topology of three-level NPC Voltage Source Inverter (VSI), and its space vector diagram. In the second part, as solution for instability problem of the input DC voltages of the APF, the authors propose a simplified Space Vector Pulse Width Modulation (SVPWM) with neutral point potential control. After that, the sliding mode regulator used to control the APF is developed. A theoretical analysis with a complete simulation of the system is presented to prove the excellent performance of the proposed technique.
|
eng_Latn
| 32,829 |
Partial aortic obstruction improves cerebral perfusion and clinical symptoms in patients with symptomatic vasospasm
|
Abstract Objective: Stroke studies in animals showed that aortic obstruction increases cerebral blood flow (CBF) and reduces infarct size. In this study we evaluate the safety and efficacy of a device providing partial and transitory aortic obstruction. Methods: We report the results in 24 selected patients with symptomatic vasospasm by aneurysmal subarachnoid hemorrhage treated by partial and transitory aortic obstruction with a novel device (NeuroFlo™, CoAxia, MN). Aneurysms were secured by coils prior to the procedure. We studied the adverse effects related to the aorta-obstructing device, and changes in CBF and neurological outcome. Results: Mean flow velocity increased in both middle cerebral arteries over 15%, and the score in the National Institute of Health Stroke Scale decreased ≥2 point in 20 patients (83%). During the procedure, three patients developed symptoms that were controlled. At 30 days follow-up, three patients had 6 points (unrelated death), three had 3 points, six had 1 point, and 12...
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Recently model order reduction techniques for second-order systems have obtained many research interests for the simulation of RCS interconnect circuits employing susceptance elements. In this paper, we propose a Block SAPOR (Block Second-order Arnoldi method for Passive Order Reduction) for multi-input multi-output RCS circuits. The proposed Block SAPOR algorithm can simultaneously guarantee passivity and achieve higher accuracy than the first order reduction technique PRIMA. Most importantly, the reduced system matrices obtained by the proposed method can preserve the structure of the original system matrices. Such a nice property makes it possible to construct an equivalent RCS circuit for the reduced system.
|
eng_Latn
| 32,830 |
Moulded circuit module, and production method therefor
|
The purpose of the present invention is to reduce the reciprocal effect exhibited in cases when electronic components which affect each other as a result of electromagnetic waves are present in one moulded circuit module. This moulded circuit module (M) is provided with a substrate (100) having a plurality of electronic components (200) mounted thereto. One electronic component (200A) is a high-frequency oscillator. A metal partition side wall part (320) is provided to the substrate (100). One surface of the substrate (100) is coated with a first resin (400) such that the electronic components (200) and the side wall part (320) are coated therewith. The first resin (400) is covered by a shield layer (600) made from an electromagnetic-wave-blocking metal. The electronic component (200A) is surrounded by the side wall part (320) and the shield layer (600).
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The paper presents a VHDL-AMS based approach to the Switched-Current (SI) Sigma-Delta Modulator design. EDA tools are presented, which translate the prototype VHDL-AMS description into SI realization. Another tool helps the designer to create the layout. The paper also describes a new proposed current mode comparator, which is used in the design. Postlayout simulation results are presented.
|
eng_Latn
| 32,831 |
Parameter switching modulation with variables feedback for hyperchaos control
|
Control method using system parameter switching modulation with variables feedback for control hyperchaotic system is studied.A 4D hyperchaotic circuit is selected as a typical example,and is controlled by using switching modulation with variables feedback on one of its capacitor parameters.Experimental simulation results demonstrate the hyperchaotic circuit can be controlled to different periodical orbit while only the magnitude of switch or the width of periodic impulse is selected properly.Hyperchaotic circuit under this kind control can be used in special signal generator or signal converters.
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We consider a spin system with competing interactions isotropic with respect to the axes of a cubic lattice in the presence of an external field. We show that for small values of the external fieldH, the paramagnetic to modulated phase transition is fluctuation-induced first order, while for larger fields, such transition changes to continuous at a tricritical point. Applications for fluids systems are proposed.
|
eng_Latn
| 32,832 |
Determination of Floquet Exponents for Small-Signal Analysis of Nonlinear Periodic Circuits
|
This paper describes an approach to determine the Floquet exponents and the related eigenfunctions of linear time-varying circuits, that represent a vehicle to implement the variational model of periodic nonlinear circuits. The Floquet exponents and eigenfunctions allow us to exploit the structure of the analytical solution of the linear time-varying circuit and, as shown, yield an efficient solution. The proposed approach allows the calculation of the Floquet exponents directly and is developed from the harmonic-balance formulation adopted to find the steady-state solution of the nonlinear periodic circuit.
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Using the relationship between the resistance, capacitance and current in Hopfield neural network, and the properties of sigmoid function, this paper gives the terse, explicit algebraical criteria of global exponential stability, global asymptotical stability and instability. Then this paper makes clear the essence of the stability that Hopfield defined, and provides a theoretical foundation for the design of a network.
|
eng_Latn
| 32,833 |
Neutral Point Potential Balancing Algorithm for Autonomous Three-Level Shunt Active Power Filter
|
0B Abstract- This paper presents a control method of the input DC voltages of three-level Neutral Point Clamped (NPC) autonomous shunt Active Power Filter (APF), which is applied to eliminate line current harmonics and compensate reactive power. In the first part, the authors present a topology of three-level NPC Voltage Source Inverter (VSI), and its space vector diagram. In the second part, as solution for instability problem of the input DC voltages of the APF, the authors propose a simplified Space Vector Pulse Width Modulation (SVPWM) with neutral point potential control. After that, the sliding mode regulator used to control the APF is developed. A theoretical analysis with a complete simulation of the system is presented to prove the excellent performance of the proposed technique.
|
We address Newton-type problems of minimal resistance from an optimal control perspective. It is proven that for Newton-type problems the Pontryagin maximum principle is a necessary and sufficient condition. Solutions are then computed for concrete situations, including the new case when the flux of particles is non-parallel.
|
eng_Latn
| 32,834 |
Visual monitoring of solid-phase extraction using chromogenic fluorous synthesis supports.
|
Reductive aminations and further transformations of an azo dye and fluorous tagged aldehyde are described. The intensely colored 2,4-dialkoxybenzyl protected amines undergo Fmoc-based peptide coupling, Suzuki reactions, and sulfonamide formation with product isolation facilitated by visual monitoring of fluorous solid phase extraction. Target compounds are released from the supports in high yields and purities by treatment with trifluoroacetic acid (TFA).
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The first problem in our third millennium is energy. For this raison, we try to find a new solution to develop different ways of distribution and energy use. This article presents the design of a sliding mode controller using sliding mode observation technique which aims to simplify the control procedure. For ameliorating the quality of the energy transferred from the power supply to the load, and minimizing the harmful effects of the harmonics generated by nonlinear load. The virtual grid flux vector estimated in the sliding-mode observer yields robustness against the line voltage distortions. We propose a new multi-function converter as an efficient solution to improve the power quality. The good dynamic and static performance under the proposed control strategy is verified by simulation and experiment .
|
eng_Latn
| 32,835 |
3.35 /spl mu/m intracavity difference frequency generator with single pump input
|
Compact, CW laser sources with output wavelengths that are matched to the fundamental absorption bands of certain molecules are required for remote sensing, pollution analysis, and medical monitoring. Although Pb-salt diodes have output wavelengths in the desired spectral region, they are quite expensive and operate exclusively at cryogenic temperatures. Nonlinear difference frequency generation is an alternative method of generating output for these applications. In this paper we describe the results of initial experiments in which a 0.807 /spl mu/m input beam was mixed with the intracavity field of a 1.06-/spl mu/m laser to generate difference frequency output at 3.35 /spl mu/m. The input beam was also used to pump the Nd:YAG laser, thus the device needs only one optical input. >
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Purpose – To provide a general method for coupled simulation of electrical machines and circuits, using finite element analysis and a circuit/system simulator.Design/methodology/approach – The electrical machine is modelled by dynamic inductance and electromotive force (EMF), which are determined by finite element analysis and updated in time‐stepping procedure. Calculation of these parameters is based on current perturbations that are applied on linearized field equations after determining the operating point by nonlinear analysis.Findings – Based on the case studies, the presented method can be utilized in coupled field‐circuit simulation and the results correlate with those obtained by other known methods. The results were also validated according to experimental data.Research limitations/implications – Calculation of the EMF and the presented implementation for SIMULINK have some limitations regarding the accuracy and stability of the numerical integration. In the future, the numerical methods could b...
|
eng_Latn
| 32,836 |
Analogue elliptical filters with digital control and memory
|
To control active filter characteristics a new type of integrated circuit (IC) of Xicor Inc. is used. This is an analogue potentiometer with digital control and non volatile memory. Usage of this IC is convenient when the storage of the last results is required. The control parameters are estimated for applications on elliptical low-pass and high-pass voltage-controlled voltage source filters. Practically obtained diagrams are given.
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Aiming at the requirements in running efficiently and high accuracy handling data timely,the login system,communication module,database storage and reading,relay verification module,report generation and printing.were designed.The working principle and composition of the calibration device were introduced.The upper computer software of microprocessor relay protection's trippingoperation-board intelligent calibration device was developed based on graphical LabVIEW language and database programming technology to realize the function of each part.The results indicate that the software can complete returning the relay operating board calibration value and action value efficiently,and has a multi-function interface.The software has been successfully applied in this device.
|
eng_Latn
| 32,837 |
Efficient Synthesis of Fluorinated Phenanthrene Monomers Using Mallory Reaction and Their Copolymerization
|
The Mallory reaction of 1,2-diarylhexafluorocyclopentene (1, aryl = 3-bromophenyl; 2, aryl = 4-bromophenyl) under light irradiation (λ = 365 nm) in the presence of iodide proceeded to give dibromophenanthrene derivatives, 3 and 4. Polycondensation of 9,9-dioctylfluorene-2,7-diboronic acid bis(1,3-propanediol)ester with the obtained monomers by Suzuki–Miyaura coupling afforded the phenanthrene-type copolymers Poly-3 and Poly-4 in high yields. For comparison, diphenylethene-type copolymers (Poly-1 and Poly-2) were also prepared analogously. UV–vis spectra of Poly-3 and Poly-4 in CHCl3 showed π–π* transition peaks at 380 and 354 nm, respectively, and additional shoulder peaks appeared at a longer wavelength in the film, suggesting the molecular assembly of the polymer molecules. In contrast, the spectra of Poly-1 and Poly-2 in solution were essentially unchanged as measured in the film, presumably owing to partial interruption of the π-conjugation system in polymer main chains. The copolymers showed photolum...
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A novel phasor computation algorithm is presented in this paper. The real and imaginary part filters of this algorithm have identical magnitude frequency characteristic (IMFC) at all the frequencies and orthogonal phase frequency characteristic (PFC) at fundamental frequency. Considering the conditions of the same magnitude frequency characteristic (MFC) and the orthogonal PFC, the two-sample algorithm is derived. Once two-sample orthogonal filters with IMFC are obtained, the algorithm design is just to select proper shapes and lengths of windows, which determine the filtering performance and response-time, respectively. This method could be applied to design filter in any window-length, especially in short-window. Therefore, this class of phasor algorithms is suitable for EHV transmission line protection where a short-window is crucial for fast response and better operation performance. The proposed algorithm has been applied to a series of EHV relay devices by China Xuchang Relay Group.
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eng_Latn
| 32,838 |
Pulse Width Modulation for DC Motor Control Based on LM324
|
The DC motor is an important part of an equipment in many industrial applications requiring variable speed and load characteristics due to its ease of controllability. Nowadays, there are lots of good-quality motor speed controllers on the market. However, their costs are relatively high. A speed controller with both low cost and good performance will be highly marketable, especially for small mobility applications. The current work allows controlling the speed of a DC motor in both forward and reversing direction, from fully off to fully on. It runs in switch mode so it is quite efficient. In this work, designing motor bi-directional DC control circuit using Pulse Width Modulation (PWM) based on an operational amplifier model LM324 is implemented. The proposed system offers many advantages such as simple structure, low cost, accurate, quite efficient, lightweight nature, small volume, and bi-directional speed control.
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Summary A low frequency noise analysing system is set up with a multi-channel detector. The multi-channel detector includes a PCD Image Sensor which has 256 sensing elements. Light output of a laser diode is divided into various wavelengths. The light spectral intensities are measured at various wavelengths.
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eng_Latn
| 32,839 |
Push‐pull (iso)quinoline chromophores: synthesis, photophysical properties, and use for white light emission.
|
The photophysical properties of a series of conjugated push-pull (iso)quinolines have been studied. The compounds were synthesized by well-established and straightforward methodologies. The materials exhibited not only emission solvatochromism in a variety of non-polar solvents, but also tunable halochromism. Some of the compounds remained moderately luminescent after protonation and these had a red emissive form, which was used to obtain white light emission, both in solution and in thin film, by the controlled protonation of the initially blue-green emitting materials. This methodology has potential applications in white OLED fabrication with two forms of a single emitter in equilibrium.
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A novel phasor computation algorithm is presented in this paper. The real and imaginary part filters of this algorithm have identical magnitude frequency characteristic (IMFC) at all the frequencies and orthogonal phase frequency characteristic (PFC) at fundamental frequency. Considering the conditions of the same magnitude frequency characteristic (MFC) and the orthogonal PFC, the two-sample algorithm is derived. Once two-sample orthogonal filters with IMFC are obtained, the algorithm design is just to select proper shapes and lengths of windows, which determine the filtering performance and response-time, respectively. This method could be applied to design filter in any window-length, especially in short-window. Therefore, this class of phasor algorithms is suitable for EHV transmission line protection where a short-window is crucial for fast response and better operation performance. The proposed algorithm has been applied to a series of EHV relay devices by China Xuchang Relay Group.
|
eng_Latn
| 32,840 |
The Implementation and Analysis of Over-modulation Technique of Three-phase Current Source Rectifier Based on FPGA
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This paper introduces an over-modulation technique, a continuous extension of space vector PWM (SVPWM) linear control scheme for the three-phase current source rectifier (CSR). By judging the magnitude of active current vectors durations, this technique can select the current vectors in sectors and modify their active durations. It is neither necessary to store a lot of data in advance nor needs complex calculation strategy, which is very suitable to a digital implementation based on field programmable gate array (FPGA). The over-modulation scheme can extend the dc output voltage range of three-phase CSR, useful in improving the dynamic response and fulfilling the specific load demands. The simulations and experiments prove that the produced scheme not only has good dynamic and static performances, but also can keep the power factor at unity in a wide range of output dc voltage and the input current harmonic THD is very low.
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This paper establishes the monitoring system of advanced metering infrastructure by power line carrier. The communication between these modules is accomplished with power lines. The master module consists of a signal transform circuit, a LCD circuit and a keyboard circuit. The master module can measure the real-time states, including the voltage, the current, the real power and the reactive power, etc.,. The control modules can be divided into types, one is air conditioning control and another is illumination control. Each control module consists of a signal transform circuit, an AVR microprocessor, a keyboard decode circuit, a LCD circuit and a power line carrier circuit. It has the functions of local and remote monitors. The air conditioning control module is installed an infrared rays control circuit for the air condition device, and the illumination control module is added a power control circuit for the illumination load.
|
eng_Latn
| 32,841 |
Draw Phase Locus of Non-linear System by Skillfully Using the Simulink Tools
|
This paper introduces using the simulink tools to draw non-linear system phase locus by three examples. The first example shows how structure diagram establish correspondence phase structure diagrams, and how to set initial conditions and draw phase locus. The second and the third examples introduce methods of using non-linear differential equation to establish phase structure diagrams, the deal way of some problem during simulation.
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The liquid level control is very popular in the iron and steel,petroleum chemical industry,food filling industry,such as to achieve the optimal complex object liquid level control,SIEMENS S7-200 PLC was used as main controller for constructing double containers level control system.Through the water and the next cistern of the series,created a pair of let object,used stability boundary method to establish the mathematical model,the model of initial parameters set PID,and set the best parameters,established a PLC single loop PID control system,and MCGS software realization of the upper machine real-time configuration and monitoring.Experimental results showed that the system is stable,reliable control and the accurate control level can be realized.
|
eng_Latn
| 32,842 |
ANALYTICAL APPROXIMATIONS TO THE SCHRÖDINGER EQUATION FOR A SECOND PÖSCHL–TELLER-LIKE POTENTIAL WITH CENTRIFUGAL TERM
|
The bound state solutions of the Schrodinger equation for a second Poschl–Teller-like potential with the centrifugal term are obtained approximately. It is found that the solutions can be expressed in terms of the hypergeometric functions 2F1(a, b; c; z). To show the accuracy of our results, we calculate the eigenvalues numerically for arbitrary quantum numbers n and l. It is found that the results are in good agreement with those obtained by other method for short-range potential. Two special cases for l = 0 and V1 = V2 are also studied briefly.
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THE INVENTION CONCERNS A CONTROL CIRCUIT FOR ANAEROBIC REACTOR SYSTEM. THE TOUR INCLUDES FILTER 16 ESTIMATE THAT RECEIVES INPUT SIGNAL SENSOR PRODUCTS AN ESTIMATE OF THE PRESENT VALUE A VARIABLE IN THE SYSTEM, COMPARE THAT ESTIMATE FOR A SIGNAL SENSOR THE VARIABLE AND PRODUCT OF THAT COMPARISON, SIGNAL ERROR dIFFERENCE IS TO COMBINE THE RECEIVED SIGNAL and reapplied INTEGRATOR, A DISPOSAL OF A BIAS LONG TERM THAT MAY BE PRESENT IN AT LEAST ONE OF SIGNALS rECEIVED, SUCH ELIMINATOR INCLUDING HIGH PASS FILTER BY 53 OR rECEIVED INPUT SIGNALS ARE TRANSMITTED TO THE iNTEGRATOR 58, SUCH FILTER HIGH PASS THAT REJECTING THE BIAS PERSISTS FOR A PERIOD CONSIDERABLY LONGER THAN THE TIME cONSTANT SYSTEM. APPLY THE iNVENTION INCLUDING THE TREATMENT OF WASTE WATER.
|
yue_Hant
| 32,843 |
Data line driving circuit of the display panel, a driver circuit, a display device
|
A data line driving circuit for a display panel includes a plurality of output circuits, a bias circuit, and a plurality of switches. Each of the plurality of output circuits includes an electric current source which supplies electric current in response to a bias signal, and supplies a data voltage by using the electric current to a corresponding one of a plurality of data lines arranged in the display panel. The bias circuit generates the bias signal, and supplies the bias signal to the plurality of output circuits through bias wirings. The plurality of switches is provided between the bias circuit and the plurality of output circuits, and cuts off the bias wirings in response to a control signal.
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This paper analyses the DCS control logic of Unit 10 in Shaoguan Power Plant, pointing out the flaws in the outlet temperature control logic of the first stage super heater, the measurement of the protect signal and the control logic of boiler feed water pumps, and gives its improvement as well. So the DCS control logic can satisfy the operation of the unit.
|
eng_Latn
| 32,844 |
Mechanism of Ion Transport in Amorphous Poly(ethylene oxide)/LiTFSI from Molecular Dynamics Simulations
|
The mechanisms of lithium cation (Li+) and bis(trifluoromethane)sulfonamide anion (TFSI-) transport in poly(ethylene oxide) (PEO, Mw = 2380) melts were examined using molecular dynamics (MD) simulations over a wide range of salt concentrations and temperatures. MD simulations using a quantum-chemistry-based many-body polarizable force field yielded ion self-diffusion coefficients, electrolyte conductivity, ion aggregation, and the coordination environment of Li+ in good agreement with experiment. Lithium transport was found to arise from a combination of the subdiffusive Li+ motion along PEO chains, motion together with PEO segments and intersegmental Li+ hops from one PEO segment to another. The rate of intersegmental hops was found to correlate well with times at which Li+ motion crosses over from subdiffusive to diffusive behavior. The contribution of Li+ motion along PEO chains to the total Li+ transport was found to be approximately equal to the contribution from Li+ moving together with PEO segments...
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A novel phasor computation algorithm is presented in this paper. The real and imaginary part filters of this algorithm have identical magnitude frequency characteristic (IMFC) at all the frequencies and orthogonal phase frequency characteristic (PFC) at fundamental frequency. Considering the conditions of the same magnitude frequency characteristic (MFC) and the orthogonal PFC, the two-sample algorithm is derived. Once two-sample orthogonal filters with IMFC are obtained, the algorithm design is just to select proper shapes and lengths of windows, which determine the filtering performance and response-time, respectively. This method could be applied to design filter in any window-length, especially in short-window. Therefore, this class of phasor algorithms is suitable for EHV transmission line protection where a short-window is crucial for fast response and better operation performance. The proposed algorithm has been applied to a series of EHV relay devices by China Xuchang Relay Group.
|
eng_Latn
| 32,845 |
[HL-A B 27 a criterion for Reiter's syndrome].
|
The prevalence of 23 HLA antigens were examined in 21 patients with a typical Reiter's disease, 21 patients with incomplete Reiter's syndrome as well as 16 patients with non-gonococcal urethritis. HLA-B 27 antigen was found in 85,7% of patients with typical Reiter's disease as compared to 7,4% of 413 healthy controls. HLA-B 27 was also detectable in 57,1% of patients with clinical suspicion of Reiter's disease. No significant difference from the control frequencies of HLA specifities was found in patients with non-gonococcal urethritis. The association between HLA-B 27 and Reiter's syndrome is so marked that tissue typing is a valuable adjunct in the diagnosis of Reiter's syndrome.
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In this paper,Routh-Hurwitz Criterior is applied to fulfill synthesized analysis and definition of the stability of second order or higher order circuit with operation amplifier and controlled source or without controlled source.A method of stability analysis of LTI circuit is got and some useful conclusions are obtained.
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eng_Latn
| 32,846 |
How to implement a switch in spice? I have designed a circuit where I want to give a pulse of very short duration using a switch. How can I implement it in spice.
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How to simulate simple on/off, Single-Pole-Single-Throw switch? I am trying to simulate ON, OFF switch in this simple circuit: V1 0 1 1.5v Rfan1 3 4 1 S1 1 4 SW ON Rwire1 6 5 0.00001 VV1 0 2 dc 0 VRfan1 3 5 dc 0 VRwire1 2 6 dc 0 .dc V1 1.5 1.5 1 .print dc i(VV1) i(VRfan1) i(VRwire1) .end but I got this error: ngspice stopped due to error, no simulation run! the circuit I am trying to simulate is like this one: if I replace the switch with a resistor, the circuit will work normally. any idea? EDIT I have fixed my switch as the following: S1 1 4 98 99 mySwitch ON .model mySwitch SW vt=0 vh=1 ron=1n roff=10k
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How do I write a correct micro-benchmark in Java? How do you write (and run) a correct micro-benchmark in Java? I'm looking for some code samples and comments illustrating various things to think about. Example: Should the benchmark measure time/iteration or iterations/time, and why? Related:
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eng_Latn
| 32,847 |
Combinatorial synthesis and high throughput evaluation of ferroelectric/dielectric thin-film libraries for microwave applications
|
A library of 256 differently doped thin films of (BaxSr1−x)TiO3 (where 0.5<x<1.0) was generated on a 1 in.×1 in. LaAlO3 substrate using multistep thin-film deposition techniques together with a quaternary masking strategy. Appropriate postannealing processing afforded high-quality epitaxial thin films. The microwave properties, i.e., dielectric constant and loss tangent, of samples in the library were characterized with a scanning-tip microwave near-field microscope at 1 GHz, and the results were found to be consistent with measurements made with interdigital electrodes. Specific dopants were found to significantly affect the dielectric constant and tangent loss. Tungsten, in particular, reduces the tangent loss.
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A novel phasor computation algorithm is presented in this paper. The real and imaginary part filters of this algorithm have identical magnitude frequency characteristic (IMFC) at all the frequencies and orthogonal phase frequency characteristic (PFC) at fundamental frequency. Considering the conditions of the same magnitude frequency characteristic (MFC) and the orthogonal PFC, the two-sample algorithm is derived. Once two-sample orthogonal filters with IMFC are obtained, the algorithm design is just to select proper shapes and lengths of windows, which determine the filtering performance and response-time, respectively. This method could be applied to design filter in any window-length, especially in short-window. Therefore, this class of phasor algorithms is suitable for EHV transmission line protection where a short-window is crucial for fast response and better operation performance. The proposed algorithm has been applied to a series of EHV relay devices by China Xuchang Relay Group.
|
eng_Latn
| 32,848 |
Milk Chemical Composition of Dairy Cows Fed Rations Containing Protected Omega-3 Fatty Acids and Fermented Rice Bran
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The research was conducted to investigate the effect of ration containing protected omega-3 and fermented rice bran on chemical composition of dairy milk. The research employed 10 female PFH dairy cows of 2-4 years old with body weight 300-375 kg. The research was assigned in randomized complete block design. The treatment consisted of P0= control ration, P1= P0 + 20% fermented rice bran, P2= P1 + 4% soya bean oil, P3= P1 + 4% protected tuna fish oil and P4= P1 + 4% protected lemuru fish oil. The results showed that the effects of fish oil supplementation in the rations significantly (P<0.01) decreased feed consumption, cholesterol, low density lipoprotein, lipids, and saturated fatty acids. Meanwhile, it increased milk production, content of high density lipoprotein, omega-3, omega-6 and unsaturated fatty acids in the dairy cows milk. It is concluded that the inclusion of 4% protected fish oil in the rations can produce healthy milk by decreasing milk cholesterol and increasing omega-3 fatty acids content.
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In this paper, a modeling and simulation method for planar interdigitated ruthenium oxide MEMS supercapacitor was proposed based on the electrochemical reaction mechanism of supercapacitor. The study simulated the planar interdigitated ruthenium oxide MEMS super capacitor using Comsol software. The highly accurate charge and discharge curves of the super capacitor, electric potential distribution graph and the concentration distribution graph were got through simulation. The effects of two structure-parameters were discussed in the research.
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eng_Latn
| 32,849 |
Upper bounds on the resistivity of a turbulent current layer
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The basie equations for a layer of an electrically conducting fluid are considered in the magnetohydrodynamic approximation. An electric field is applied parallel to the layer. Because of various instabilities, turbulent fluid motions will be generated in general. The goal of the analysis presented in this paper is the derivation of upper bounds for the average turbulent resistivity of the layer. In order to demonstrate the concept of the upper bound theory, only the simplest case will be treated and the boundary conditions will be assumed in such a way that the analogy with the problem of bounds on the momentum transport in a turbulent Couette layer can be utilized.
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In this paper,Routh-Hurwitz Criterior is applied to fulfill synthesized analysis and definition of the stability of second order or higher order circuit with operation amplifier and controlled source or without controlled source.A method of stability analysis of LTI circuit is got and some useful conclusions are obtained.
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eng_Latn
| 32,850 |
Influence of scattering processes on the electronic properties of composite fermions
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Sweeping the magnetic field at low temperatures can result in metastable states of the system of two-dimensional electrons in GaAs/AlGaAs. These non-equilibrium states are stable in the range of filling factors 1/3 < ν < 1, but can be changed by an extremely small variation of magnetic field around ν = 1. We used this phenomenon to vary the disorder and to study its influence on the electronic properties of two-dimensional electrons in the vicinity of ν=1/2. The temperature dependence of σ xx at ν = 1/2 was analyzed, and logarithmic corrections to conductivity were found.
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A novel phasor computation algorithm is presented in this paper. The real and imaginary part filters of this algorithm have identical magnitude frequency characteristic (IMFC) at all the frequencies and orthogonal phase frequency characteristic (PFC) at fundamental frequency. Considering the conditions of the same magnitude frequency characteristic (MFC) and the orthogonal PFC, the two-sample algorithm is derived. Once two-sample orthogonal filters with IMFC are obtained, the algorithm design is just to select proper shapes and lengths of windows, which determine the filtering performance and response-time, respectively. This method could be applied to design filter in any window-length, especially in short-window. Therefore, this class of phasor algorithms is suitable for EHV transmission line protection where a short-window is crucial for fast response and better operation performance. The proposed algorithm has been applied to a series of EHV relay devices by China Xuchang Relay Group.
|
eng_Latn
| 32,851 |
Effect of infrared filter on the electrical characteristics of silicon-based PIN photo-detectors
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The p-n junction is one of the most widely used technology in the semicondector device. In the various pn junction types like photodiode, solar cell and LED etc., the dark leakage current can determine the device performance and power. Therefor it is very important to minimize the dark leakage current and to optimize the device performance.[1] Among these various pn juncton diodes, photodiode has been used for a long time in the detect sensor device field. One of the important parameters in the photodetectors is the device senstivity to light. In order to enhance the photo-senstivity, many types of light filter has been tasted and used to maximize the device performance. In this present work, the dark current and photo current have been studied by measurment of I-V and C-V at different light intensity. The photo senstivity on the infrared filter types also has been investigated.
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This article introduces the method of intelligent regulation to control the Buck power-electronic converter using a newly developed small-signal model of the pulse width modulation switch. The implemented method uses a fuzzy-PID controller that is tuned using the global search method of genetic algorithm. The experimental simulation results show that the used intelligent hierarchical regulation method using the GA- tuned fuzzy-PID controller, for the utilized new PWM small- signal model, produces the desired system response for performance enhancement of the electronic switching-mode Buck converter despite the occurrence of noise with comparatively high amplitudes.
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eng_Latn
| 32,852 |
Piecewise control strategy for electric spring
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Electric spring (ES) as a device to solve the voltage fluctuation problem caused by the connection of a large number of renewable energy sources to the power grid has developed quickly. ES which involves a power inverter with a capacitor in DC side (ES-C) with the simple structure and low cost has great potential for application with strict control requirements and some operation details are not been discussed. In this study, based on the analytical solution of ES-C's operating points, the operation region of ES-C is divided into four parts. Also, a piecewise control strategy was proposed to ensure the safe and stable operation of ES-C. With the piecewise control, ES-C can participate in system frequency regulation while maintaining load voltage as rated voltage. Also, the simulations in PSCAD/EMTDC proved that the proposed piecewise control can switch between operation regions and can make full use of the operating points of ES-C.
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This paper present a fast convolution method to be used in fitting the γ spectrum of scintillation crystal PbWO 4 and gives the light yeildof the crystal. It replaces the time costing convolution calculation with a seriesrecursion, which greatly improves the speed of fitting with little loss of preciseness.
|
eng_Latn
| 32,853 |
The Role of Phosphorus in Crop Protection: Commercial and Experimental Weed Control Agents
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During the last ten years there have been significant changes in the role that Phosphorus has played in Crop Protection. In commercial terms, sales of organophosphate insecticides have steadily declined; this has been due to the withdrawal of a number of products due to regulatory and industry pressure, along with the introduction of safer, lower-use rate insecticides. With herbicides, the story is different; due to the introduction of genetically modified crops, sales of products such as Glyphosate and Glufosinate have increased. In the area of fungicides, Phosphorus has so far had little impact. Despite these successes, new crop protection agents containing Phosphorus that have reached the market place remain elusive. In this article, I discuss some recent market trends and summarize some approaches toward identifying new herbicides containing Phosphorus.
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The strip thickness control system is difficult to establish an accurate mathematical model, and traditional PID control strategy has a poor adaptive ability, so the effect of control is always not satisfying. According to the problems above, a new control strategy of self-tuning PID controller based on RBF neural network whose parameters are optimized by PSO algorithm is proposed in the paper. The control method integrates advantages of RBF neural network as well as PID controller and good global search capability of PSO algorithm. The simulation results indicate that the method not only improves control performance and dynamic quality, but also has strong self-adapting ability and robustness. It achieved a very good control effect when used in strip thickness control system that proved the correctness and effectiveness of the control method.
|
eng_Latn
| 32,854 |
Ethynylphenyl-Derivatized Free Base Porphyrins: Anodic Oxidation Processes and Covalent Grafting onto Glassy Carbon Electrodes
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In six of seven cases, direct anodic oxidation of the ethynyl group of an ethynylphenyl-derivatized free-base porphyrin gave modified glassy carbon electrodes in which the porphyrin was strongly surface-bound, most likely in a perpendicular geometry through covalent attachment of the ethynyl group to a surface carbon atom. The porphyrins each contained an ethynylphenyl group in one meso position and varied in the groups present in the other three meso positions. Electrografted 5,10,15,20-tetrakis(ethynylphenyl)porphyrin, H21, which has ethynyl moieties in all four meso positions, has well-defined surface voltammetry and grows to multilayer levels upon repeated cyclic voltammetry (CV) deposition scans. Multilayering was not observed to the same degree for monoethynylphenyl-substituted porphyrins and became progressively less for porphyrins having groups in the 15-meso position that were more protective against ethynyl radical attack. Clean molecular monolayer-level coverage was observed for 5-ethynylphenyl...
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A novel phasor computation algorithm is presented in this paper. The real and imaginary part filters of this algorithm have identical magnitude frequency characteristic (IMFC) at all the frequencies and orthogonal phase frequency characteristic (PFC) at fundamental frequency. Considering the conditions of the same magnitude frequency characteristic (MFC) and the orthogonal PFC, the two-sample algorithm is derived. Once two-sample orthogonal filters with IMFC are obtained, the algorithm design is just to select proper shapes and lengths of windows, which determine the filtering performance and response-time, respectively. This method could be applied to design filter in any window-length, especially in short-window. Therefore, this class of phasor algorithms is suitable for EHV transmission line protection where a short-window is crucial for fast response and better operation performance. The proposed algorithm has been applied to a series of EHV relay devices by China Xuchang Relay Group.
|
eng_Latn
| 32,855 |
A novel hybrid current control method applied in three-phase fourleg APF
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Based on the analysis of circuit of a three-phase four-leg APF,a conclusion was put forth,which means that the current control of the three power legs is independent from the neutral leg.A novel hybrid control method was presented.SVM was used to control the output current of the three main power legs,while hysteresis current control was applied to control the output current of the neutral leg. As a result,the current control of four legs was decomposed into the control of the three main power legs and the control of neutral leg,which can sharply simplify the current control of APF.Compared with other current control methods,this new method has advantages such as easy of calculation,control and realization.Simulation results prove the correctness of this method.
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This paper presents an algorithm to resolve superimposed action potentials encountered during the decomposition of electromyographic signals. The algorithm uses particle swarm optimization with a variety of features including randomization, crossover, and multiple swarms. In a simulation study involving realistic superpositions of two to five motor-unit action potentials, the algorithm had an accuracy of 98%.
|
eng_Latn
| 32,856 |
Generation of polarization entangled photons using concurrent type-I and type-0 processes in AlGaAs ridge waveguides
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A technique to generate polarization entangled photons using concurrent type-I and type-0 second-order nonlinear processes in monolithic Bragg reflection waveguides is presented and analyzed. Concurrent phase matching is achieved by lithographic tuning of the waveguide ridge width. Nearly perfect entanglement is achievable on-chip through appropriate epistructure design without the need of spectral filtering and group velocity compensation. Theoretical calculations predict that a high quantum interference visibility could be experimentally achieved with the pair generation rate of each process being approximately 3.0×106 pairs/s/mW/GHz
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A novel phasor computation algorithm is presented in this paper. The real and imaginary part filters of this algorithm have identical magnitude frequency characteristic (IMFC) at all the frequencies and orthogonal phase frequency characteristic (PFC) at fundamental frequency. Considering the conditions of the same magnitude frequency characteristic (MFC) and the orthogonal PFC, the two-sample algorithm is derived. Once two-sample orthogonal filters with IMFC are obtained, the algorithm design is just to select proper shapes and lengths of windows, which determine the filtering performance and response-time, respectively. This method could be applied to design filter in any window-length, especially in short-window. Therefore, this class of phasor algorithms is suitable for EHV transmission line protection where a short-window is crucial for fast response and better operation performance. The proposed algorithm has been applied to a series of EHV relay devices by China Xuchang Relay Group.
|
eng_Latn
| 32,857 |
Preparation of an optically activated field effect transistor based on diamond film
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Freestanding diamond (FSD) film with p-type hydrogen-terminated nucleation surface was prepared by microwave ::: plasma chemical vapour deposition (MPCVD) method. The post-treatment (wet chemical etch and annealing process) on ::: the property of diamond film was investigated. The preparation and characterization of hydrogen-terminated diamond ::: film p-type channel metal-semiconductor field effect transistors (MESFETs) was studied. The device was also used for ::: photodetector application. The results showed the potential of high switching speed and high sensitivity to ultraviolet ::: (UV).
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A novel phasor computation algorithm is presented in this paper. The real and imaginary part filters of this algorithm have identical magnitude frequency characteristic (IMFC) at all the frequencies and orthogonal phase frequency characteristic (PFC) at fundamental frequency. Considering the conditions of the same magnitude frequency characteristic (MFC) and the orthogonal PFC, the two-sample algorithm is derived. Once two-sample orthogonal filters with IMFC are obtained, the algorithm design is just to select proper shapes and lengths of windows, which determine the filtering performance and response-time, respectively. This method could be applied to design filter in any window-length, especially in short-window. Therefore, this class of phasor algorithms is suitable for EHV transmission line protection where a short-window is crucial for fast response and better operation performance. The proposed algorithm has been applied to a series of EHV relay devices by China Xuchang Relay Group.
|
eng_Latn
| 32,858 |
Control module for an electrical circuit breaker, procedures for operation and electrical system protection.
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Control module (20) with interrupt function for an electrical protection switch (10) connectable externally, comprising: - a voltage input (28) for a control voltage (U), - an outlet (32a) driving the control voltage (U), which can connect a circuit breaker (22), - an inlet (32b) which can connect the breaker (22) for a return of the control voltage ( U), - a connection (36) connected to the input (32b) to the circuit breaker (10), and - a measurement unit (46) for measuring the intensity (I1,2) and / or voltage (U1 , 2) to the inlet (32b) and the outlet (32a), characterized in that - between the input (32b) and the connection (36) a control switch (40) for the circuit breaker (10) is connected.
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The paper presents a VHDL-AMS based approach to the Switched-Current (SI) Sigma-Delta Modulator design. EDA tools are presented, which translate the prototype VHDL-AMS description into SI realization. Another tool helps the designer to create the layout. The paper also describes a new proposed current mode comparator, which is used in the design. Postlayout simulation results are presented.
|
eng_Latn
| 32,859 |
Ramp controlled driver for series/parallel solid state lighting devices
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E OLED driver device is disclosed, which includes a DC-DC converter stage with a waveform generator for generating a converter set value with the profile, with a minimum rise time and fall time value.
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The paper presents a VHDL-AMS based approach to the Switched-Current (SI) Sigma-Delta Modulator design. EDA tools are presented, which translate the prototype VHDL-AMS description into SI realization. Another tool helps the designer to create the layout. The paper also describes a new proposed current mode comparator, which is used in the design. Postlayout simulation results are presented.
|
eng_Latn
| 32,860 |
Highly Sensitive Thin-Film Field-Effect Transistor Sensor for Ammonia with the DPP-Bithiophene Conjugated Polymer Entailing Thermally Cleavable tert-Butoxy Groups in the Side Chains
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The sensing and detection of ammonia have received increasing attention in recent years because of the growing emphasis on environmental and health issues. In this paper, we report a thin-film field-effect transistor (FET)-based sensor for ammonia and other amines with remarkable high sensitivity and satisfactory selectivity by employing the DPP-bithiophene conjugated polymer pDPPBu-BT in which tert-butoxycarboxyl groups are incorporated in the side chains. This polymer thin film shows p-type semiconducting property. On the basis of TGA and FT-IR analysis, tert-butoxycarboxyl groups can be transformed into the −COOH ones by eliminating gaseous isobutylene after thermal annealing of pDPPBu-BT thin film at 240 °C. The FET with the thermally treated thin film of pDPPBu-BT displays remarkably sensitive and selective response toward ammonia and volatile amines. This can be attributed to the fact that the elimination of gaseous isobutylene accompanies the formation of nanopores with the thin film, which will fa...
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A novel phasor computation algorithm is presented in this paper. The real and imaginary part filters of this algorithm have identical magnitude frequency characteristic (IMFC) at all the frequencies and orthogonal phase frequency characteristic (PFC) at fundamental frequency. Considering the conditions of the same magnitude frequency characteristic (MFC) and the orthogonal PFC, the two-sample algorithm is derived. Once two-sample orthogonal filters with IMFC are obtained, the algorithm design is just to select proper shapes and lengths of windows, which determine the filtering performance and response-time, respectively. This method could be applied to design filter in any window-length, especially in short-window. Therefore, this class of phasor algorithms is suitable for EHV transmission line protection where a short-window is crucial for fast response and better operation performance. The proposed algorithm has been applied to a series of EHV relay devices by China Xuchang Relay Group.
|
eng_Latn
| 32,861 |
Silencing Suppressor Protein VPg of a Potyvirus Interacts With the Plant Silencing-Related Protein SGS3
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Viral genome-linked protein (VPg) of potyviruses is involved in multiple steps of the potyvirus infection cycle, including viral multiplication and movement in plants. Recently, we showed that VPg of Potato virus A (PVA; genus Potyvirus) suppresses sense-mediated RNA silencing, which is linked to one or both nuclear or nucleolar localization. Here, we studied interactions between VPg and components of the plant RNA silencing pathway. Results showed that VPg interacts with the SGS3 protein of Solanum tuberosum and Arabidopsis thaliana, as shown by yeast two-hybrid analysis and bimolecular fluorescence complementation assays. VPg–SGS3 interactions co-localized with small cytoplasmic bodies that contained plant RNA-dependent RNA polymerase 6 (RDR6) (likely SGS3/RDR6 bodies). The N-terminal zinc finger (ZF) domain of SGS3 was the main determinant of the VPg interaction. Our data also suggest that the ZF domain controls SGS3 localization. SGS3 homodimerization was controlled by multiple protein regions. The VP...
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0B Abstract- This paper presents a control method of the input DC voltages of three-level Neutral Point Clamped (NPC) autonomous shunt Active Power Filter (APF), which is applied to eliminate line current harmonics and compensate reactive power. In the first part, the authors present a topology of three-level NPC Voltage Source Inverter (VSI), and its space vector diagram. In the second part, as solution for instability problem of the input DC voltages of the APF, the authors propose a simplified Space Vector Pulse Width Modulation (SVPWM) with neutral point potential control. After that, the sliding mode regulator used to control the APF is developed. A theoretical analysis with a complete simulation of the system is presented to prove the excellent performance of the proposed technique.
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eng_Latn
| 32,862 |
Diode circuit for protection of ESD
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The utility model provides a diode circuit for protection of ESD, which solves the problems of limited situation for application frequency band, great influence on the output power of a radio frequency circuit and reception sensitivity, and easily signal limiting amplitude distortion in the prior art. The diode circuit comprises a first diode and a second diode; wherein one end of the first diode is connected with an input end, and the other end is connected with a power supply. One end of the second diode is connected with the input end, and the other end is connected with the earth. The utility model provides bidirectional and preferable electrostatic discharge ESD protection for the radio frequency circuit of high frequency and high level, and the antistatic ability of the radio frequency port is improved from between general several hectovolts and a kilovolt to more than 8 kV, ensuring that the disturbance of the electrostatic discharge of ESD doesn't make any influence to the system in most conditions.
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The paper presents a VHDL-AMS based approach to the Switched-Current (SI) Sigma-Delta Modulator design. EDA tools are presented, which translate the prototype VHDL-AMS description into SI realization. Another tool helps the designer to create the layout. The paper also describes a new proposed current mode comparator, which is used in the design. Postlayout simulation results are presented.
|
eng_Latn
| 32,863 |
Design of active disturbance rejection controller for the velocity loop of optical tracking servo system
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For the optical tracking servo system with characteristics of large inertia and the non-linear friction, the improved ADRC (active disturbance rejection controller) method is designed to improve the velocity response of the servo system. This paper establishes a mathematical model of servo system and introduces the ADRC's working principle, then based on the step of the ADRC method, the parameters are given by simulation analysis, finally, the compared experiments are finished on the actual optical tracking servo system between the traditional PID controller and ADRC method. The actual results show that the ADRC method can not only achieve high speed fast step response without overshoot, and improve low-speed stability, its performance is better than traditional PID controller. Besides, the ADRC method can also improve the optical servo system speed performance by inhibiting the saturation and other nonlinear factors.
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Abstract Cyber security problem in energy system has been paid more and more attention recently. In this paper, impact of the packet loss and bit errors in the communication process on the performance of demand response was evaluated. Thermodynamic modelling mechanism of the typical electric heat pumps was first discussed. And, a novel heat pump demand response control strategy based on Optimal Temperature Regulation (OTR) was proposed. The control strategy was then applied to balance the power fluctuations caused by renewable energy. Packet loss and bit errors in the signal transmission were discussed, and their impact on the performance of the control strategy was analysed. Finally, case studies were used to validate the given method.
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eng_Latn
| 32,864 |
Power factor improvement of an AC-DC converter via appropriate sPWM technique
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The power control of a DC load can be achieved via an AC-DC converter consisting of a rectifier bridge and a switching element operating by sPWM technique. The use of such a converter causes a lot of high harmonics at the AC side, which reduce the power factor and distort the grid voltage. Using passive filter in the converter input to avoid the high harmonics consequences the power factor decrease. To improve the power factor an appropriate sPWM operation of the switching element is proposed in this paper. The system behavior is studied through simulation and experimental investigation. The power factor correction is verified.
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The paper presents a VHDL-AMS based approach to the Switched-Current (SI) Sigma-Delta Modulator design. EDA tools are presented, which translate the prototype VHDL-AMS description into SI realization. Another tool helps the designer to create the layout. The paper also describes a new proposed current mode comparator, which is used in the design. Postlayout simulation results are presented.
|
eng_Latn
| 32,865 |
Voltage mode universal filters employing single FDCCII
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In this paper, four new voltage-mode universal biquad filters configuration are proposed. First of two circuits proposed high-input impedance universal filter with single-input and three-outputs, which can simultaneously realize voltage mode low-pass, band-pass and high-pass filter responses employing all grounded passive components. The third proposed universal filter three-input and single-output, which also can realize all the standard filter functions. The fourth circuit proposed universal filter with three-input and five-outputs, which can be used as either a three-inputs single-output or a two-inputs five-outputs universal filters. It can realize all five different generic filtering signals: low-pass, band-pass, high-pass, band-stop and all-pass. Simulation results are given to confirm the theoretical analysis. The proposed biquad filters are simulated using TSMC CMOS 0.35 μm technology.
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FANUC POWER MATE i-H is used to the modular machine tool widely,Its multi-path function adopt to the requirement of separate multi-station of modular machine tool.But this system can not supply servo spindle function.This paper will introduce to apply converter and FANUC Analog output model ADA02B to get stepless speed for spindle and multi-path spindle function.
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eng_Latn
| 32,866 |
Preparation and Photovoltaic Characterization of Free‐Base and Metallo Carboxyphenylethynyl Porphyrins for Dye‐Sensitized Solar Cells
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Free-base, manganese, iron, cobalt, nickel, copper and zinc 5-(4-carboxy-phenylethynyl)-10,20-biphenylporphines are synthesized to study the impact of central metal ions to the photovoltaic performance of the solar cells.
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A novel phasor computation algorithm is presented in this paper. The real and imaginary part filters of this algorithm have identical magnitude frequency characteristic (IMFC) at all the frequencies and orthogonal phase frequency characteristic (PFC) at fundamental frequency. Considering the conditions of the same magnitude frequency characteristic (MFC) and the orthogonal PFC, the two-sample algorithm is derived. Once two-sample orthogonal filters with IMFC are obtained, the algorithm design is just to select proper shapes and lengths of windows, which determine the filtering performance and response-time, respectively. This method could be applied to design filter in any window-length, especially in short-window. Therefore, this class of phasor algorithms is suitable for EHV transmission line protection where a short-window is crucial for fast response and better operation performance. The proposed algorithm has been applied to a series of EHV relay devices by China Xuchang Relay Group.
|
eng_Latn
| 32,867 |
Iminophosphine palladium(II) complexes: synthesis, characterization, and application in Heck cross-coupling reaction of aryl bromides
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Palladium(II) complexes containing phosphorus and nitrogen donor atoms (iminophosphine), dichlorido{N-[2-(diphenylphosphino)benzylidene]-2-trifluoromethylaniline}palladium(II) 1, dichlorido{N-[2-(diphenylphosphino)benzylidene]-3-trifluoromethylaniline}palladium(II) 2, dichlorido{N-[2-(diphenylphosphino)benzylidene]-2-methylaniline}palladium(II) 3, dichlorido{N-[2-(diphenylphosphino)benzylidene]-3-methylaniline}palladium(II) 4 have been successfully synthesized and fully characterized by FT-IR and NMR (1H, 31P, 19F, and 13C) spectroscopy techniques. These complexes were first step tested in the reaction of bromobenzene and styrene to determine the optimal coupling reaction conditions and then successfully applied as catalysts for Heck cross-coupling reactions of activated and deactivated aryl bromides with styrene derivatives and several acrylates. Copyright © 2014 John Wiley & Sons, Ltd.
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A novel phasor computation algorithm is presented in this paper. The real and imaginary part filters of this algorithm have identical magnitude frequency characteristic (IMFC) at all the frequencies and orthogonal phase frequency characteristic (PFC) at fundamental frequency. Considering the conditions of the same magnitude frequency characteristic (MFC) and the orthogonal PFC, the two-sample algorithm is derived. Once two-sample orthogonal filters with IMFC are obtained, the algorithm design is just to select proper shapes and lengths of windows, which determine the filtering performance and response-time, respectively. This method could be applied to design filter in any window-length, especially in short-window. Therefore, this class of phasor algorithms is suitable for EHV transmission line protection where a short-window is crucial for fast response and better operation performance. The proposed algorithm has been applied to a series of EHV relay devices by China Xuchang Relay Group.
|
eng_Latn
| 32,868 |
Research on the Half-differential Annular Angle Sensor
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A new angle sensor used to electronic control fuel system is studied and designed.Its structure,the- ory and measuring circuit are analysed. Experimental results show the sensor characteristic can meet the de- mand of properties of electronic control fuel system.
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The analogue integration of a signal is useful in many areas of physics and electrical engineering. We describe a temperature stable passive integrator capable to measure the signal in the frequency range up to 170 MHz.
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eng_Latn
| 32,869 |
Power Quality Improvement Using UPFC Controller
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This paper describes the methods of improving quality of power in transmission line using UPFC a facts controller. UPFC Unified power flow controller enhances the control method using advanced semiconductor switching. The aim of the paper is to Regulatevoltage, Impedance Control, Powerfactor Improvement, Real and Reactive Power Compensation. These compensations can be done by shunt and series connected inverter switching. Matlab simulations were performed to realize the compensation.
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Abstract Two methods for calculating activity coefficients of ultra-low sulfur diesel (ULSD) and its blends with pure alcohols (C1–C5), namely, UNIFAC-continuous and UNIFAC-Dortmund-continuous, are presented. ULSD was modeled as a continuous blend of paraffins, naphthenes, and aromatics. The molar distribution in each family was expressed as a function of carbon number using the gamma distribution function. The parameters of the distribution function can be easily fitted from experimental distillation data of ULSD and extrapolated to n-alcohol/ULSD blends. The activity coefficients obtained were used to model the ASTM D86 distillation curves. UNIFAC-Dortmund-continuous exhibited the best fitting to the experimental results. Based on that, three new correlations for calculating the boiling point, vapor pressure and structural groups of complex ULSD are proposed here.
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eng_Latn
| 32,870 |
New method for determining parasitic access inductances of high frequency on-wafer coplanar heterojunction bipolar transistors
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New analytical extraction procedure is developed for determining independently the parasitic inductances of high frequency on-wafer coplanar Heterojunction Bipolar Transistor. It takes into account the influence of inductive effect due to other device parameters which can not be neglected for these transistors and it does not require any numerical optimizations or special test structures. In particular the analytical expressions demonstrate that base resistance and intrinsic and extrinsic base-collector capacitances have a significant effect on the accurate determination of the HBT parasitic inductances. Our theoretical investigations are validated using two types of transistors: A on-wafer coplanar GalnP/GaAs HBT and a microstrip mounted GalnP/GaAs which have a unity current gain cutoff frequency of 80 GHz respectively.
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The first step of the /spl Hscr//sub /spl infin// loop shaping design procedure is to specify desired closed loop performance by shaping the singular values of the nominal plant with a pre- and/or a post-compensator. Designers usually choose diagonal weighting functions but it is not always possible to obtain the desired loop shape with diagonal weights. This paper develops a systematic procedure for designing nondiagonal pre- and post-compensators. Such nondiagonal weighting functions enable the designer to shape each singular value of the nominal plant separately. To illustrate the procedure an /spl Hscr//sub /spl infin// loop shaping controller is designed for a plant whose singular values can not be shaped accurately using diagonal weights.
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eng_Latn
| 32,871 |
Radioimmunoassay of porcine growth hormone -- methodological studies.
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A double antibody radioimmunoassay for immunoreactive growth hormone in porcine plasma has been evaluated on the basis of dilution and recovery experiments as well as by examination of accuracy and reproducibility. The sensitivity was better than 0.10 ng/ml. The cumulated within-assay coefficient of variation was between 2--4% and the cumulated between-assay coefficient of variation was 9.6%. The normal fasting values correspond well to those of other investigators.
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The strip thickness control system is difficult to establish an accurate mathematical model, and traditional PID control strategy has a poor adaptive ability, so the effect of control is always not satisfying. According to the problems above, a new control strategy of self-tuning PID controller based on RBF neural network whose parameters are optimized by PSO algorithm is proposed in the paper. The control method integrates advantages of RBF neural network as well as PID controller and good global search capability of PSO algorithm. The simulation results indicate that the method not only improves control performance and dynamic quality, but also has strong self-adapting ability and robustness. It achieved a very good control effect when used in strip thickness control system that proved the correctness and effectiveness of the control method.
|
eng_Latn
| 32,872 |
The Imbalance Short-circuit Simulation and Data Processing of Electric Power System Based on EMTP/ATP and Matlab
|
This article introduces the simulation procedure and results of imbalance short-circuit of electric power system based on EMTP/ATP,and provides how to turn the EMTP/ATP data to the data that Matlab can process,and the source code of the important values of U、I、P、Q、I2,etc.,needed in the electric power protection by Matlab.
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In this paper, we consider the second order wave equation discretized in space by summation-by-parts-simultaneous approximation term (SBP-SAT) technique. Special emphasis is placed on the accuracy analysis of the treatment of the Dirichlet boundary condition and of the grid interface condition. The result shows that a boundary or grid interface closure with truncation error $\mathcal{O}(h^p)$ converges of order $p + 2$ if the penalty parameters are chosen carefully. We show that stability does not automatically yield a gain of two orders in convergence rate. The accuracy analysis is verified by numerical experiments.
|
eng_Latn
| 32,873 |
Corrosion Inhibition of AMT in Copper-5% Citric Acid System
|
The corrosion inhibition of AMT in copper 5% citric acid system was studied by polarization curve, EIS, XPS and STM. AMT had good inhibiting efficiency in this system. Addition of the inhibitor increased the resistance of both cathodic and anodic processes by forming a layer of complex film. The structure of thefilm was discussed.
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Design of Control System for Water Conductance Instrument controlled by LPC2131 MCU which has the control capability of ARM is introduced in this paper,and the problem which is about the temperature excursion is solved.The design adopts the bi-directional pulsed voltage as its source,which reduces the negative of capacitive and polarization effects at the electrodes.Software arithmetic is designed to compensate the offset of temperature coefficients of Water Conductance Instrument.With this method,the signal is digitally corrected by microprocessor based on the compensation coefficients determined from pretest data.The error problem of temperature compensation in the process of water conductivity measurement is better solved.
|
eng_Latn
| 32,874 |
The Design of Micromanipulator Based on Piezo Actuator
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In this paper, we describe a mcromanipulate mechanism used the converse piezoelectric effects, The micro-step mechanism based on converse piezoelectric effects is designed. Alternative signals programming from the computer is driving the piezo actuator by means of a dynamic power. The micro step motion of the the micro-step mechanism is realized used the electrostrictive effect and alternative clamping the guide staff, the position of Micro-step Mechanism is precise controlled.Micro gripper that actuated by piezoelectric cantilever was developed for the need of micro parts assembly.
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Due to the continuous decrease of the solar cells cost, photovoltaic energy is used in different applications. The most important one is the water pumping system powered by photovoltaic generators. These systems can work with or without storage battery. With the increased use of this application, more attention has been paid to their optimum utilization. Many methods have been developed to determine the maximum power point (MPP). In this paper, to control the DC bus voltage, we apply field oriented control (FOC) strategy to induction motor (IM) supply by a photovoltaic (PV) system. And to maximize the efficiency of the proposed PV pumping system, we use the fuzzy logic controller (FLC) and the classical Perturb and Observ (P&O). Different tests have been carried to prove the effectiveness of the proposed control system. KeywordsPumping Photovoltaic system, Fiel oriented contorl, MPPT, Fuzzy logic controlle, Perturb and Observ .
|
eng_Latn
| 32,875 |
Light Scattering by Shock‐Cooled Isotactic Polypropylene Film
|
An absolute low‐angle light scattering photometer is described which is used for the quantitative evaluation of the light scattering exhibited by shock‐cooled isotactic polypropylene films. Following Stein and Wilson the supermolecular order is considered to be describable in terms of a density correlation function γ(r) and an orientation correlation function f(r), which are both dependent only upon the magnitude of the distance r between individually scattering volume elements. By means of Fourier transformations performed upon the horizontally and vertically polarized components of the scattered light under polarized incident light, these functions can be obtained. It is found that γ(r)=exp(−r2/a2), with a ≅40 000 A and f(r)=B exp(−r2/b2)+C exp(−r2/c2), with B=0.544, b=4500 A, C=0.456, and c=17 000 A. The density correlation thus reaches much further than the orientation correlation. This is ascribed to the poorly developed spherulitic crystallization due to the shock cooling of the sample. This meaning...
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A novel phasor computation algorithm is presented in this paper. The real and imaginary part filters of this algorithm have identical magnitude frequency characteristic (IMFC) at all the frequencies and orthogonal phase frequency characteristic (PFC) at fundamental frequency. Considering the conditions of the same magnitude frequency characteristic (MFC) and the orthogonal PFC, the two-sample algorithm is derived. Once two-sample orthogonal filters with IMFC are obtained, the algorithm design is just to select proper shapes and lengths of windows, which determine the filtering performance and response-time, respectively. This method could be applied to design filter in any window-length, especially in short-window. Therefore, this class of phasor algorithms is suitable for EHV transmission line protection where a short-window is crucial for fast response and better operation performance. The proposed algorithm has been applied to a series of EHV relay devices by China Xuchang Relay Group.
|
eng_Latn
| 32,876 |
A circuit for stabilizing the electron current to the anode of a hot-filament device
|
A circuit is described which overcomes most of the problems associated with stabilizing the electron current to the anode of a hot-filament device which is working under temperature limited conditions. Provision is made to vary the collected electron current over the range 1 μA to 10mA, with an outgassing facility up to 100 mA. All the interelectrode voltages may be varied over a 200 V range without significantly affecting the ionising current. The circuit has been incorporated into a universal instrument for testing ion gauges 1,2 but it could be adapted, by adding suitable extra voltage sources, to operate other vacuum devices such as mass spectrometers. Various refinements and protection facilities are described which give the operator more freedom to make electrical parameter changes without the fear of burning out the filament of the device under test during space-charge limited conditions.
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In this paper,the design for eigenstructure assignment is discussed.The Linear Design Method for minimal order E-compensator is given,in which the attached P polse can be assigned in a stable(fixed,arbitrary)position.The uniformity of eigenstructure assignment capability for EO-compensator,E-compensator and state feedback is proved.
|
eng_Latn
| 32,877 |
Variable-order fractional equivalent circuit model for lithium-ion batteries
|
Battery models play important roles in battery manufacturing, design, safe operation, and many of its applications, such as in providing power sources of electric vehicles due to the high energy density, long life, and high cell voltage. Unlike the detection of impedance spectrum in a short linear interval, the I-V characteristic of lithium-ion batteries presents strongly nonlinearity such as the serious polarization in both ends of charging /discharging. To modeling the nonlinear characteristic of real battery accurately, this paper proposes a variable-order fractional equivalent circuit model that provides a novel and effective trade-off of model accuracy and simplicity. The proposed method is verified under the working conditions of pulse and constant current charging /discharging, where the maximum model error is less than 1.8%.
|
This article introduces the C8051F single-chip micro-computer and the LCD controller KS0108.Using them as the core,we have designed the single-chip micro-computer LCD system.In the thesis,we put emphasis on the technology of graphic dynamic display,and describe the LCM's hardware and software features.The circuit that we have designed is emulated in the C8051F020 single-chip micro-computer emulation experiment system.That experimental result shows that we have achieved the expected goal in the design.
|
eng_Latn
| 32,878 |
Application of PI Control Algorithm to Discrete Manufacturing Systems
|
PI( proportional-integral) control algorithm is applied to control VIP (work-in-progress) in a discrete manufacturing system, where the cascade control of PI controllers is presented. It is in the frequency domain that the PI controller is designed with constraints on sensitivity options to ensure the stability and robustness of its parameters. A case is evaluated on a motorcycle engine crankcase production system, whose simulation results confirm that demand fluctuations can be compensated by PI controllers under a normal demand. PI controllers also possess low sensitivity to the distribution of production times.
|
This paper analyses the causationes that influence the precision of the weighing system.Introduces the characteristics of the chip ADS1230 and designing of hardware circuit in weighing system.This design uses the most extensive and mature technology AT89C51 chip microcontroller and the resistance strain weighing sensor chip.The system has many characteristics-rapid weighing,exact and steady data,ease using,high anti-jamming ability etc.
|
eng_Latn
| 32,879 |
Truncation criteria for model reduction using balanced realisation
|
It is shown with an example that the reduction technique using balanced realisation suggested previous (Moore 1981) may not retain the most significant states. An example is presented which shows that there are cases where the truncation of states using the second-order modes instead of d/sub i/ (products of the second-order modes and the input or output vector of the balanced realisation) leads to better approximation of the impulse response. >
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In this paper,Routh-Hurwitz Criterior is applied to fulfill synthesized analysis and definition of the stability of second order or higher order circuit with operation amplifier and controlled source or without controlled source.A method of stability analysis of LTI circuit is got and some useful conclusions are obtained.
|
eng_Latn
| 32,880 |
Analysis and testing of DC motor control system for electric bike
|
The proposed electric bike is driven by using a 24V350WDC motor and VRLA 24V battery as a source of voltage. Input point settings are done by pressing the speed control button in the form of digital data, which is then converted to voltage by the microcontroller. The output of the microcontroller in the form of a PWM becomes input for the motor driver, where the output speed of the motor will be detected by the speed sensor. The automation used is the PI method using the Zeigler Nichols 2 tuning formula. The control method using PI had been analyzed and tested, resulting in Kp=3.37 and Ki=0.73. The electric bike has been tested with different loads. The proposed electric bike was successfully controlled and able to be driven with a minimum speed of 5km/h and a maximum speed of 20km/h.
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This paper describes an all Verilog full chip simulation technique using Verilog macro-models for analog functions and a Verilog noise model simulating the affects of digital cross-talk. Correlation between simulated results and a prototype are shown. The prototype is a 16-bit 1Msample/s pipelined analog-to-digital converter (ADC) with on chip 32-bit micro-controller. Models for operational amplifiers, analog comparators, capacitors, analog switches, and digital cross-talk noise are developed using Verilog syntax. These Verilog macro models are used to build the analog section of the pipelined ADC and are incorporated in a full chip mixed-signal simulation.
|
eng_Latn
| 32,881 |
The application of photo-conductors as voltage variable operational elements in iterative analogue computation†
|
This paper is concerned with the application of photo-conductors as variable operational resistor elements in iterative analogue computation. Suitable control circuits have been devised which achieve a linear relationship between a controlling voltage level and the resistance of the variable operational element. The use of crystal lumps in conjunction with silicon photo-detectors enables control circuit settling times of the order of 180 µsec to be achieved and results indicate that with the correct choice of detector, the speed of the controlled response is limited only by the performance of the operational amplifier in the control circuit.
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The digital controller of the traveling system of the asphalt paver based on the PIC16F877 single chip computer is introduced in this paper The paper accomplishes the software and hardware design of the control system, integrates the PID and fuzzy control into the design of the digital controller so as to conduct constant velocity control under paving The thesis proves fuzzy ad justable PID control is superior to traditional PID control by simulation and analysis
|
eng_Latn
| 32,882 |
F-atom deexcitation of DF(ν = 1): isotope effect
|
Abstract The 1 → 0 vibrational transition probability of DF(ν = 1) + F → DF(ν = 0) + F has been calculated based on the collinear collision of F—D…F. A comparison of the result with that of HF(ν = 1) + F yields the information that DF(ν = 1) relaxes two to three times faster than HF(ν = 1) in the temperature range 100–3000 K.
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A novel phasor computation algorithm is presented in this paper. The real and imaginary part filters of this algorithm have identical magnitude frequency characteristic (IMFC) at all the frequencies and orthogonal phase frequency characteristic (PFC) at fundamental frequency. Considering the conditions of the same magnitude frequency characteristic (MFC) and the orthogonal PFC, the two-sample algorithm is derived. Once two-sample orthogonal filters with IMFC are obtained, the algorithm design is just to select proper shapes and lengths of windows, which determine the filtering performance and response-time, respectively. This method could be applied to design filter in any window-length, especially in short-window. Therefore, this class of phasor algorithms is suitable for EHV transmission line protection where a short-window is crucial for fast response and better operation performance. The proposed algorithm has been applied to a series of EHV relay devices by China Xuchang Relay Group.
|
eng_Latn
| 32,883 |
Extraction Method of Compensation Current Reference for Three-Phase Delta-Connected Active Power Filter
|
In the process of compensation current reference extraction for three-phase delta-connected APF(active power filter), fast dynamic response and high accuracy are required of the harmonic current extraction. The fundamental frequency compensation current and the line voltage of the grid should be orthogonal. In view of these two problems, the relationship between the compensation current references of delta-connected APF and the load currents is derived based on the theory of reactive compensation admittances network. Using this relationship, an integrated current extraction strategy is proposed in this paper. In this method, relevant reference currents are calculated based on the generalized instantaneous reactive power theory and use of filters. Simulation and experiment results verify the fast dynamic response and accuracy of this approach.
|
Recently, we have developed an integration approach for the calculations of ionization potentials (IPs) and electron affinities (EAs) of molecular systems at the level of second-order Møller-Plesset (MP2) (Su, N. Q.; Xu, X. J. Chem. Theory Comput. 11, 4677, 2015), where the full MP2 energy gradient with respect to the orbital occupation numbers was derived but only at integer occupations. The theory is completed here to cover the fractional occupation systems, such that Slater's transition state concept can be used to have accurate predictions of IPs and EAs. Antisymmetrized Goldstone diagrams have been employed for interpretations and better understanding of the derived equations, where two additional rules were introduced in the present work specifically for hole or particle lines with fractional occupation numbers.
|
eng_Latn
| 32,884 |
P-Q instantaneous power theory – a correct theory or useful algorithm for switched compensator control
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In this presentation methods useful for determining instantaneous power in the three-phase circuits with periodic nonsinusoidal waveforms have been presented. It may be applied to control shunt active power filter working in real-time. Shunt active filtering is an effective method to eliminate current harmonics. The theoretical considerations have been illustrated by a simulation example carried out for many various operating conditions.
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A large class of time-varying filters can be described via pseudo-differential operators belonging to the Hormander class OPS 0 0 , 0. The questions whether and how an input signal can be reconstructed from a known output lead to the problems of invertibility of pseudo-differential operators in that class and of (at least, numerical) solution of pseudo-differential equations. We are going to derive effective conditions for the invertibility for pseudo-differential operators with globally slowly varying symbols as well as for causal pseudo-differential operators, and we study the stability of the finite sections method with respect to time and frequency for these operators.
|
eng_Latn
| 32,885 |
Triplet State Properties of the OLED Emitter Ir(btp)2(acac): Characterization by Site-Selective Spectroscopy and Application of High Magnetic Fields
|
The well-known red emitting complex Ir(btp)2(acac) (bis(2-(2‘-benzothienyl)-pyridinato-N,C3‘)iridium(acetylacetonate)), frequently used as emitter material in OLEDs, has been investigated in a polycrystalline CH2Cl2 matrix. The studies were carried out under variation of temperature down to 1.2 K and at magnetic fields up to B = 10 T. Highly resolved emission and excitation spectra of several specific sites are obtained by site-selective spectroscopy. For the preferentially investigated site (I → 0 at 16268 cm-1), the three substates I, II, and III of the T1 triplet state are separated by ΔEII-I = 2.9 cm-1 and ΔEIII-I = 25.0 cm-1, respectively. ΔEIII-I represents the total zero-field splitting (ZFS). The individual decay times of these substates are τI = 150 μs, τII = 58 μs, and τIII = 2 μs, respectively. The long decay time of the lowest substate I indicates its almost pure triplet character. The time for relaxation from state II to state I (spin−lattice relaxation, SLR) is as long as 22 μs at T = 1.5 K,...
|
A novel phasor computation algorithm is presented in this paper. The real and imaginary part filters of this algorithm have identical magnitude frequency characteristic (IMFC) at all the frequencies and orthogonal phase frequency characteristic (PFC) at fundamental frequency. Considering the conditions of the same magnitude frequency characteristic (MFC) and the orthogonal PFC, the two-sample algorithm is derived. Once two-sample orthogonal filters with IMFC are obtained, the algorithm design is just to select proper shapes and lengths of windows, which determine the filtering performance and response-time, respectively. This method could be applied to design filter in any window-length, especially in short-window. Therefore, this class of phasor algorithms is suitable for EHV transmission line protection where a short-window is crucial for fast response and better operation performance. The proposed algorithm has been applied to a series of EHV relay devices by China Xuchang Relay Group.
|
eng_Latn
| 32,886 |
Frequency and phase selective magnetostatic wave switch
|
A new type of magnetostatic wave gate microwave switch, which has both frequency and phase selectivity features, is presented. This switch is triggered by microwave signal and has output amplitude modulation over 30 dB and phase sensitivity about 1 dB/grad. Only the signals which match the gate frequency and phase are passed by the switch, therefore it fulfils not only switching features but features of a phase and frequency matched filter as well.
|
The first problem in our third millennium is energy. For this raison, we try to find a new solution to develop different ways of distribution and energy use. This article presents the design of a sliding mode controller using sliding mode observation technique which aims to simplify the control procedure. For ameliorating the quality of the energy transferred from the power supply to the load, and minimizing the harmful effects of the harmonics generated by nonlinear load. The virtual grid flux vector estimated in the sliding-mode observer yields robustness against the line voltage distortions. We propose a new multi-function converter as an efficient solution to improve the power quality. The good dynamic and static performance under the proposed control strategy is verified by simulation and experiment .
|
eng_Latn
| 32,887 |
I have some components here to make an SMPS from mains for a CV/CC power supply for my workshop, and I decided to add a linear post-regulator to smooth the output. To avoid big heatsinks I wanted the SMPS voltage to follow the post-regulator voltage when I adjust it, and I've found a possible solution from . However my simulations showed better results while using an OpAmp (image below). As you can see, I set up the comparator of the SMPS in a way that the output voltage of the post-regulator will determine the output voltage of the SMPS (keeping it always 5V more then the post-regulator output for example, precision is not a problem). The circuit works fine on simulation, however I wanted to know if ripple, noises or imperfections of hardware that doesn't exist in my simulation might make this a bad idea, and what filters should I study to put on the output of this OpAmp (if any) to avoid any problems with this "follower" circuit before I buy the components I need. I have another comparator not shown in the image that is doing the current sensing.
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I'm trying to find a way of building a new power supply for my workshop, in order to keep it small and not so hot I will be using a spare xformer to step down mains to 24v and then a variable buck converter to adjust it (and CC mode, displays and blinky stuff). I thought it would be a good idea to use a linear regulator on the output stage to smooth things out, but I can't seem to think of a control scheme that allows me to change the voltage using only one potentiometer. The buck stage is this topology but with a external PNP transistor.(It has already been prototyped, it works alright, I know the mc34063A is old) The only idea I got that ""works"" is using the buck converter output as a reference for a linear regulator (IC or discrete parts), but using a SMPS output as reference for anything is a bad idea, due to the amount of noise and fluctuations. This is the sort of output stage I can and have built (or bought) over time. Just a big discrete regulator. In short: How to control a MC34063A step down (buck) converter so it follows the output stage +1-3 V of headroom.
|
The new Top-Bar does not show reputation changes from Area 51.
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eng_Latn
| 32,888 |
A small signal model for average current mode control based on describing function approach
|
Modeling of V2 Current-Mode Control
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Characterization and performance comparison of ripple-based control for voltage regulator modules
|
eng_Latn
| 32,889 |
Analysis and Design of Average Current Mode Control Using a Describing-Function-Based Equivalent Circuit Model
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A new continuous-time model for current-mode control with constant frequency, constant on-time, and constant off-time, in CCM and DCM
|
From Eyes to Face Synthesis: a New Approach for Human-Centered Smart Surveillance
|
eng_Latn
| 32,890 |
pls. help me answer this question, lots of thanks!
|
In no particular order ..... \n\nAt low frequencies the necessarily high values of L and C can result in an inconveniently large size. \n\nAn active filter, which can be designed to exhibit and work with higher impedance values means that smaller values of C can be used.\n\nAdditionally the use of a gyrator configuration can eliminate the need for L.\n\nA passive filter is inherently lossy, at least to some extent.\nAn active filter can have gain.\n\nAn active filter is usually smaller than a passive one.\n\nA passive filter doesn't require a power source.
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Directions how to do this can be found in the text book.\n\nDo your own homework!
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eng_Latn
| 32,891 |
Cascade PID controller for quadrotor
|
Simulation of Furnace Cascade PID Control System Based on Matlab / Simulink
|
Mental Health Smartphone Apps: Review and Evidence-Based Recommendations for Future Developments
|
eng_Latn
| 32,892 |
Estimation and mitigation of current harmonics using improved control schemes
|
Experimental Design of a Nonlinear Control Technique for Three-Phase Shunt Active Power Filter
|
Comparison of Voltage-Source and Current-Source Shunt Active Power Filters
|
eng_Latn
| 32,893 |
Altitude control of quadrotor using fuzzy self tuning PID controller
|
Handbook of Pi and Pid Controller Tuning Rules
|
Essential amino acids are primarily responsible for the amino acid stimulation of muscle protein anabolism in healthy elderly adults
|
eng_Latn
| 32,894 |
Speculative Memory Checkpointing
|
CLOCK-Pro: An effective improvement of the clock replacement
|
Goertzel Algorithm Based Shunt Active Power Filter Using Sliding Mode Controller
|
eng_Latn
| 32,895 |
Modeling a hysteretic modulator's PFM and PWM modes
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A small signal model for average current mode control based on describing function approach
|
A Generative Word Embedding Model and its Low Rank Positive Semidefinite Solution
|
eng_Latn
| 32,896 |
An enhanced adaptive frequency locked loop for variable frequency controls
|
Characterization and performance comparison of ripple-based control for voltage regulator modules
|
Improving Intelligence Analysis With Decision Science.
|
eng_Latn
| 32,897 |
Rogowski current sensor design and analysis based on printed circuit boards (PCB)
|
Current Sensing Techniques: A Review
|
A Lip Contour Extraction Method Using Localized Active Contour Model with Automatic Parameter Selection
|
eng_Latn
| 32,898 |
Design of Fractional Order PID controller for dc motor using Genetic Algorithm
|
Design of Fractional Order Controllers Based on Particle Swarm Optimization
|
A Brain-Computer Interface Controlled Auditory Event-Related Potential (P300) Spelling System for Locked-In Patients
|
eng_Latn
| 32,899 |
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