Applied Mechanics and Materials Vols. 397-400

Abstract: LED (light emitting diode) is a solid luminescent source of fairly wide uses, a type of electronic components capable of transforming electric energy to luminous energy, which, emitted from LED, is highly centralized and strongly directive. LED can be driven simply by low-voltage direct current. This paper chiefly introduces the actualization of drive circuits by the constant current pattern, and proposes a type of high-power LED constant current drive solutions based on the constant current drive circuit PT4115. This drive circuit is simple, highly efficient and cost effective, suitable for the market demand of solar energy products.

Abstract: A optimized Rijndael algorithm which can execute effectively on STM32F103 processor is presented. Firstly, a theoretical analysis of the Rijndael algorithm and code optimization are carried out, and then simulation results of the optimized algorithm on stm32f103 processor are given. Subsequently, the conclusions as follow can be drawn. The cycles of key schedule for decryption are more than those for encryption. Key schedule for decryption demands larger memory than that for encryption. Decryption is slower than encryption. At last, the experiment shows that the algorithm can be executed on STM32F103 processor efficiently.

Abstract: A remote control system for smart home is designed based on Z-wave, which is divided into two components: controller and receiver. In the controller design, the key signals are scanned by SCM P89LPC9408 to generate and transmit different control commands to Z-wave module, and then the relative commands are packed by Z-wave protocol and transmitted from a wireless network, LCD module is used to display the relative information such as time and temperature. In the receiver design, the Z-wave signal is received by receive module, and the transmission commands are demodulated and transmitted to SCM P89LPC938 to realize the relative functions. The results show that this system has a certain application value for smart home design.

Abstract: As feature dimension of integrated circuits (IC) come into nanometer nodes, yield problems caused by random defects get worse. Even with advanced process techniques, the yield could not achieve 100%. Accurate prediction of yield can point out the direction of process optimization, shorten the production cycle, reduce the production cost, and then increase profits. In this paper, some kinds of random defects which can influence random yield are summarized. Then some widely used yield models are outlined and the drawbacks of these models are analyzed. At last, an improved yield model is proposed with the combination of Poisson model and negative binominal model. This model which takes distributions of random defects into consideration is more flexible and accurate. It can be seen from the simulation results that comparing to those existing models, the improved model indeed has higher fidelity and more flexibility.

Abstract: This paper presents a K band (18GHz-26.5GHz) shunt capacitive micro-electromechanical systems (MEMS) switch. This switch used the coplanar waveguide (CPW) Defected ground structure (DGS) which is made by etching defect structure in CPW ground line. Furthermore the beam structure of the proposed switch is composed of one girder and two supporting beams. The design of the switchs structure is benefit to the apart between the DC signal and AC signal. The simulated values of the isolation of the switch on off-states is-55 dB at18.9 GHz, and the return loss at K band is greater than-0.3 dB. The pull-in voltage of the switch is 13.3 V.

Abstract: This article based on the theoretical basis of sampled fiber grating, using transfer matrix method to analyse sampled fiber grating, and the analysed the spectrum of sampled fiber grating, and studied sampled fiber grating filter properties. by adjusting the parameters of sampling grating such as: the length of the grating, grating period, duty ratio ( sampling rate) and other parameters, to construct 6 comb filter, and finally come to sampled fiber grating filter preparation method and process in the theory, analysed the application of sampled fiber grating filter in some optical fiber communication fields.

Abstract: Based on the demand of power department, a protection & monitoring device for the power distribution line is studied. The device using DSP as the core technology is a new industrial control unit, which adopts the of dual CPU of DSP+DSP and consists of chip selection unit, A/D conversion, data storage, watchdog circuit, press key, switch quantity detection, control output, communication, display and clock etc. The software system includes two parts: tracking software and protection software. The device ensures the high reliability and feasibility, at same time incarnates the advantage of microprocessor protection by intelligent designs.

Abstract: To study the performance of auxiliary power unit in extended range electric vehicle, simulation model of auxiliary power unit and its control system are established with MATLAB/Simulink. The method of decoupling control achieved engine speed control and generator torque control. Finally actual power responds change of required power quickly.

Abstract: With the rapid economic development and the increasing energy demand, solar energy as an important part of the renewable energy is taking more and more attention. In this paper, photovoltaic maximum power control strategies have been studied in this context, and MPPT method based on fuzzy variable step is proposed, it makes up the inadequate of traditional methods like perturbation observation method, incremental conductance method, intermittent scanning method and the constant voltage method. Build photovoltaic physics experiment platform, preparation of a variable step size control to achieve program, and simulation and experimental verification that the method can fast-track the changes in the weather, achieve MPPT, it has excellent dynamic and steady-state performance.

Abstract: With the increasing demands of power quality, high-quality power supply has become a necessary condition of modern social life. Power quality problems include voltage sag/swell, voltage unbalance and harmonics. To solve the above problem, a multi objective reactive power compensation device considering fault current limiting is designed, which can provide a certain degree of reactive power compensation to solve multi-objective system powered composite power quality problems during the normal working of the power system, and be able to quickly to limit the short-circuit current mode switching when power system under fault conditions. Finally, on the basis of theoretical analysis, experiments and simulations confirmed the correctness and effectiveness of the control strategy.