Applied Mechanics and Materials Vols. 433-435

Abstract: Permanent magnet synchronous motor (PMSM) now is widely used in hybrid vehicle drive area. When the space vector pulse width modulation (SVPWM) is used in PMSM control, the stator three phase currents must be collected for its control calculation. In this paper, a PMSM stator current collection system based on C8051F500 and AD7865 is designed, and proved to be effective with experiments.

Abstract: The design of a 2.4GHz radio-over-fiber (ROF) laser diode drive amplifier using TSMC 0.18-um CMOS technology is presented in this paper. The proposed drive amplifier is a single-ended two-stage amplifier with the operating voltages of 1.8V and 3.3V. The technique of dynamic bias is employed to enhance linearity. The post simulation results show that the linear amplifier achieves the power gain of 26.26dB, the output 1dB compression point of 20.49dBm at 2.4GHz. The maximum power added efficiency (PAE) is 27.97%. The components are all on chip including the input and output matching network, and the die size is 1.065mm×0.73mm.

Abstract: Small radio frequency identification (RFID) tag antennas are generally designed to achieve conjugate matching with capacitive chips at the called tag resonant frequency. An approximate equivalent circuit is proposed to represent the antenna input impedance in low loss dielectric materials. It consists of a shunt conductance considered to be linearly proportional to loss tangent, an input resistance and reactance of antenna in lossless materials. Comparing with the simulated result of full wave numerical tool, the equivalent circuit gives acceptable errors in input resistance and reactance at the tag resonant frequency and nearby. The simple equivalent circuit can be used to reduce the repetitive simulation work for different loss tangent.

Abstract: In order to improve the intellegence of the solar hot water system, we design the communication module of solar hot water system based on GSM short message. The communication module is composed of embedded dual serialport MCU, GSM module and level conversion circuit. The paper introduces the hardware structure of the communication module and the serial communication protocol between single chip and control instrument, then analyzes the working process of the communication module. The combination of the GSM short message technology and solar hot water system enhances the intelligent level of solar hot water system.

Abstract: To tackle the problems brought by the wired terminal multiplying and complexity of the wireless terminal cluster, the thesis designed handheld terminal design based on the wireless sensor Internet for contestants. It solves problems such as complex cluster and bad communication performance of the terminals in traditional contests with the help of zigbee technology. Besides the common function, it possesses extra functions, such as voice prompting, judge scoring and audience voting. The thesis mainly deals with the hardware and software design. The test result shows such design can better meet the needs of sorts of contests with the advantages of automatic networking, multiple function and stable performance, etc.

Abstract: According to the new execution of 2010 International Cardiopulmonary Resuscitation (CPR) & Emergency Cardiovascular Care (ECC) Guide Standard above American Heart Association (AHA), this paper designs an improved CPR simulation control system based on wireless telemetry,deferent from the original CPR simulation control system based on SCM, the new design is a monitoring system based on wireless sensing method, with several wireless monitoring node and a wireless base station consists of a wireless receiving device and PC.The system can be applied to Life first-aid training for Maritime College, crew training center and the sea rescue team etc.

Abstract: The necessary condition for power devices with enough blocking properties is Junction termination technology. In this paper, starting with the dose of rings, 3.3 kV Floating Filed Rings was investigated, and the influence of electric field and current density on the breakdown characteristic is also described. The results show that the dose of field rings directly affects the stability of breakdown voltage, this impact is relevant to the location of the peak electric field and the peak current density when breakdown was occurred. When the peak electric field appears in the middle of the field rings, the breakdown voltage is not sensitive to the dose of rings; however, when the peak electric field and strongest current density appeared on the edge of termination at the same time, breakdown voltage become very sensitive to the dose of rings because of the highest impact ionization in this position. Simulations and experiments indicate that the junction termination has better withstand voltage stability , when electric field distributes uniformly, the position of breakdown is in the middle of the termination, and the strongest current density appears in the main junction.

Abstract: A gate opening apparatus based on the absolute value photoelectric encoder of AVM58 type is designed. The internal structure and software design are introduced. It overcomes the disadvantages of low accuracy and poor reliability during gate opening detecting with the contact type encoder and solves the hidden security problem that when the system is powered down the gate travel can not be accurately recorded with the increment type photoelectric encoder. The practical applications in some water conservancy facilities show that it has good effect. For the lifting height of 40 meters, the opening detection precision is up to 1mm, and when the system is powered down, the decline or other moving distance of the gate can be accurately recorded, so the accuracy and safety of the gate control are improved.

Abstract: Both the networking mode and data transmission mode of the field mobile seismic station concern such matters as richness, real-time and effectiveness of seismic data. In light of the effectiveness, distance, cost and construction relating to data transmission in the field environment, CAN bus was utilized to connect the scattered seismic collection nodes, and the embedded microprocessor ARM was used to manage collection nodes within a certain scope. In addition, both the multiple task operating system Linux and application framework Qt were employed to construct a seismic network local management system, which significantly simplified the management task of mobile station. Such networking and data transmission mode shows such features as lower cost, easy construction, and higher reliability and instantaneity, also enables the possibility of constructing a mobile collection station with larger scale.

Abstract: In this paper, the discrete memoryless multiple-access wiretap channel (MAC-WT) with non-cooperative encoders is studied, where two users (cooperation between the users is not allowed) transmit their corresponding confidential messages (no common message) to a legitimate receiver, while an additional wiretapper wishes to obtain the messages via a wiretap channel. The inner and outer bounds on the capacity-equivocation region are provided forthis new model, and the result is further explained via a binary example.