Showing papers in "Chinese Journal of Electron Devices in 2007"

Summary of EMG Feature Extraction

Abstract: Electromyography (EMG) signal analysis has great value in the fields of clinical diagnosis, rehabilitation, bionic control, engineering application and so on, while feature extraction is the basis of EMG signal analysis. After reviewing such methods that are used to extract the characteristics of EMG signals, the paper concluded four main kinds of methods: time-domain, frequency-domain, time-frequency and nonlinear dynamics analysis methods. Based on a brief introduction to above methods, the paper compares the advantages and disadvantages of each method and predicts their application prospects in the correlative fields of EMG analysis.

Multidisciplinary Design Optimization of Heat Sink

Abstract: The multi-parameter constraint structural optimization procedure based on the combination algorithms of DOE,RSM,GA and MOST,are carried out on the Plate Fin Heat sinks for the minimization of the rate of entropy generation.With the help of data that are established in the process of optimization the overall thermal and fluid performances of the Plate Fin Heat sinks are explored and two correlations concerning Nusselt number and friction factor as the functions of geometrical and operational parameters are developed by the multivariate nonlinear regression analysis,Specific expression of thermal resistance and the rate of entropy generation are offered.Optimization results coincide with the followed analyses and related documents.

Adaptive PLL Based Carrier Tracking Algorithm for GPS Signals in High Dynamic Environments

Abstract: A four-dimensional Kalman filter based adaptive phase-locked loop(PLL) algorithm is proposed for the carrier tracking of high dynamic GPS signalsThe equivalence between Kalman filer and digital phase-locked loop is derived and the corresponding loop update method is proposedThe simulation results show that the RMS frequency error performance is improved obviously compared with the fixed-gain digital phase-locked loop(DPLL) algorithm

Mobile Robot Locating and Tracking System Design Based on Wireless Sensor Network

Abstract: A mobile robot location and navigation system is designed and implemented based on wireless sensor network, which estimates the distance between robot and beacon node by using the RSSI ( Signal Strength Indicator) between them. By using adaptive Kalman Filter algorithm, the mobile robot’s status information, which includes position, speed and acceleration, is available. In order to improve the real-time performance of system and reduce the computation overhead of robot CPU, some beacon nodes are chosen by certain rules to implement the locating program. The robot and beacon nodes use the CC2430 as the communication and data processing unit. Experiments show it has the advantages of high position precision, easy realization and low cost.

Pipelined High-Speed Implementation of SMS4

Abstract: A pipelined high-speed implementation of SMS4 Standard algorithm is described.The implementation is based on the analysis of the attributes of SMS4.Although this method sacrifices a certain area,but significantly enhanced the speed of the encryption and decryption.

Effect of Temperature on the Young's Modulus of Silicon Nano-Films

Abstract: At different temperature(100 K、300 K、400 K、500 K),molecular dynamics(MD) simulations are used to study the Young's modulis along [110] and [110] directions of silicon nano-films with reconstructed {100} surfaces.The results show that there is a difference of 25 GPa between these two Young's modulis.And the variation ratio of the Young's modulus to the temperature is nearly equal.At the same time,the results also show that the coefficients of thermal expansion along these two directions have nearly the same value.

Design of High-Speed CCD Image Data Acquisition Hardware System

Abstract: A high-speed image data acquisition system was proposed . Because of the large amount of CCD image data, the system adopted fibre channel hard disk to store the data and finally achieve a high speed of 850MB/s.Now It has been well applied in the course of CCD image data acquisition.

Adaptive Temporal Filter Based on Motion Compensation for Video Noise Reduction

Abstract: Noise in video signals will degrade the quality of image.A temporal adaptive filter based on a motion-compensation is proposed for noise reduction.The noise in video sequence is tracked by the motion-compensation in temporal domain.The filtering strength can be adaptively changed on the motion situation of a subject.The experimental results show that the proposed filter is better than that in spatial domain.The noise in video signals can be effectively reduced and the image will not be so blurry as the result of spatial filter.

Auto-Focusing System Based on DSP

Abstract: Due to the development of digital image process theory, auto-focusing system is changed from optic to digital image process now. An auto-focusing system including the functions of image sampling, preprocessing and real-time control is introduced. This system bases on the core digital signal processor chipset TMS320C6416. The hardware, principles and algorithms of this real-time digital image processing system are presented. The result indicates that the system has good properties of real time, stability and auto-focusing fast and exactly.

Maximum Fuzzy Entropy and Particle Swarm Optimization (PSO) Based Infrared Image Segmentation

Abstract: Maximum fuzzy entropy has been proven to be an efficient method for image segmentation.The key problem associated with this method is to find the optimal parameter combination of membership function so that an image can be transformed into fuzzy domain with maximum fuzzy entropy.However,it is computationally intensive or even impossible to find the optimal parameter combination of membership function directly.A new optimization algorithm,namely,PSO algorithm is used to search optimal parameter combination.Each particle represents a possible parameter combination.A swarm of particles are initialized and fly through solution space for targeting the optimal solution.The proposed method is used to segment infrared image and ideal segmentation results can be obtained with less computation cost.

Projectile Initial Velocity Storage Measurement and Test System Based on Piezoelectric Accelerometer

Abstract: Aiming at some characteristics of the interior ballistic,such as high temperature,high pressure,short time and fast velocity change, strong impact and vibration,high-speed sampling and storage of projectile acceleration in the interior ballistic was realized by utilizing 742A10-type piezoelectric impact accelerometer of Kistler company and adoping CPLD as control coreProjectile initial velocity was obtained through integrating projectile acceleration,and further its measurement precise was evaluatedThe key technique and arithmetic precision of the system were carefully analyzedThe experimental results show that the precision of the system was 093%,the system can satisfied the requirement of projectile initial velocity storage measurement and test

Simulated Study of Coupled Chaotic Systems' Spatiotemporal Dynamics

Abstract: The spatiotemporal dynamics behavior and system characteristic has been discovered for a new system coupled by some chaotic systems with same structure.Computer simulation shows its bifucations diagram,and Lyapunov exponent.Relationship between coupled systems' root mean square error of chaotic trajectory's excursion and the number of coupled chaotic system has been studied too.Results show that the new system is still in chaos,keeps sensitivity of initial states,.At the same time,it can reduce the unstableness of chaotic trajectories,which can help to restrain noise in the initial condition.

Design of High Speed Data Collecting and Processing System in Time Based on FPGA and DSP

Abstract: The design of high speed data collecting and processing system based on ADC+FPGA+DSP is introduced in order to capture and detect quickly the lidar's echo and process in time.The lidar's echo is converted to digital signal by the high-speed ADC and is buffered by FIFO using PingPang mechanism in time.The digital signal is real-timely processed by the digital signal processor(DSP).The design is simplified,reliable,real-time.It has the 200 MHz sampling rate,8 bit vertical resolution and 2 M×32 bit off-chip memory with realizing several kinds of trigger mode such as instantaneous triggering Post-trigger or Pre-trigger and software trigger.The system can accurately compute distance and velocity and real timely give an alarm in advance.It can exactly calculate the distance and speed of the object and raise the alarm in time.The scheme of the system and the main modules are presented in detail.

New Pixel Driving Circuit for Active-Matrix OLED-on-Silicon

Abstract: A new pixel driving circuit for active-matrix OLED(Organic Light Emitting Diode) on silicon with three transistors is proposed.The circuit can solve the problem that traditional MOS current operating in the saturation region simply cannot handle very small OLED pixel currents(smaller than 1 μA) given the pixel areas.With software of H-spice,this new circuit and the conventional two-transistor pixel driving circuit are simulated and compared.Simulation results show that this new proposed circuit is more suitable for OLED-on-silicon to realize multiple gray levels.

On Parsing of NMEA0183 Protocol

Abstract: The module,parsing NMEA0183 protocol,is a critical part in the guiding system software.The robusticity and efficiency of the module affect the performance of the guiding system directly.The deep analysis of the NMEA0183 protocol structure and the compilation technology characteristic leads to the method for parsing NMEA0183 protocol using the compilation technology.The whole process is composed of four phases:lexical analysis,syntax analysis,semantic analysis and code generation.Now,the method has been used in the GPS guiding system product.The corresponding module works stably in practice,and meets the request of the product level.

Investigation on Application of Phase Change Thermal Control in Electronic Devices

Abstract: A Phase-change thermal control composites(PTCC) filled with the phase change material of paraffin was presented,which is used to protect electronic devices from high temperature.The thermal control effectiveness of PTCC for electronic devices was tested by simulate experiment.The effect of the heat flux and the content of paraffin are also analyzed contrastively.The results showed that,the surface temperature of electronic devices could be under 70℃ during 939~7 500 s,while the content of paraffin in volume is about 72% and the heat flux is in the range of 1 000 W/m2 to 3 000 W/m2,and the PTCC generally can meet the demand of thermal control for some electronic devices.

Design of a High Performance Embedded UART

Abstract: Based on the FSM theory,the design of an embedded UART is performed in this paper,which supports the interface of an AMBA(Advanced Microcontroller Bus Architecture) 2.0 APB(Advanced Peripheral Bus).An improved asynchronous FIFO is proposed,which can generate empty and full flags more correctly while improving the transmission speed.Also,a new approach with easy operation and convenient realization is presented to deal with the fractional frequency division.It had been tested on FPGA.Embedded in the system,it had realized the transmission of data with that of ARM PSK system at any bit rate within 230 K in the condition of UART clock 12.5 M.Results of the test prove the feasibility of the design.

Optic Flow Target Tracking Method Based on Corner Detection

Abstract: In order to solve target lost shortcomings of the traditional target tracking system because of target's rotation,transformation etc, a kind of new tracking method is proposed.This method uses Harris corner detection algorithm to draw several typical target corner features and then uses optic flow algorithm to match the corresponding corner point.In the end,the target displacement is computed by bary centre algorithm.The proposed method uses the property of corner extracting algorithm's high speed and representing target's shape and optic flow match's high resolution.It is proved by test that this method arrives at high tracking precision and has the robust feature to target's rotation,transformation,shelter,etc.

Ka-Band Monolithic Low Noise Amplifier

Abstract: Design and fabricate a kind of Ka band monolithic low noise amplifier(LNA) with 0.25 μm GaAs PHEMT process.The characteristics of PHEMT applicable to LNA are brought.The circuit uses a four-stage structure.Microstrip line networks are used for the matching of input,output and inter-stages.The parameters of devices are ascertained by a multi-purpose optimization including gain,noise figure,VSWR,and so on.Across the 26.5～36 GHz frequency band,the LNA chip has small signal gain more than 20 dB;The noise figures are better than 3.0 dB at the most test points;At the frequency of 34 GHz,the noise figure is only 1.94 dB; The chip size is 2.88 mm×1 mm.

Design and Numerical Simulation of Small Axial Fan

Abstract: According to integration design concept of forced air convection cooling system,aerodynamic design of small axial fan for the CPU is implemented.File of 3D curves which is produced from Fortran is imported into Pro/E to build solid modeling.The performance curve of fan prototype which is fabricated by CNC is measured in a standard wind tunnel.To reduce costs and shorten the design time,CFD is carried out to predict the performance of fan.Outflow angle of fan provides basis for the design of streamline heat sink.The conclusion that the numerical simulation result is agreed with experimental data make preparation for the system numerical simulation.

Design of Intelligent Management System of Digital Library Based on RFID

Abstract: This article introduces a design method of intelligent management system of digital library based on RFID.After illustrating the working principle of the system and its whole structure,the designing method is explained from hardware and software design.The whole system consists of a PC,three Reader modules(the guard's room,the entrance,and the exit) and other peripheral circuits.The system uses dynamic ALOHA anti-collision algorithm to read all the tags and make relevant processing in order to avoid reliably the incorrect identification due to the collision of multi-tags'.It also discusses and analyzes communication-network mode between multi-Readers and PC.

Analysis and Optimal Design of Bonding Interconnects in LTCC Millimeter Wave

Abstract: Bonding interconnect is the critical technique for realizing interconnect of millimeter wave multi-chip module. Distances of bonding interconnect and dimensions of bonding pads have important effects on its millimeter wave characteristics.Commercial 3D electromagnetic analysis soft ware was used to model and analysis for the millimeter wave characteristics of bonding interconnect in low temperature co-fired ceramics. The wires of bonding interconnect designed by a 5 order low-pass filter model maximize bond-wire length and landing pad size to the alleviate influence of error, improving accuracy and reliability. A model of bonding wire interconnects for millimeter wave application is constructed, which is based on neural network methods. With the results from IE3D analyses as the learning procedures of the neural network, the parameters optimized by genetic algorithm is obtained, which shorts design time.

Study on Message Packet Communication Mechanism of Wireless Sensor Network Based on TinyOS-2.x

Abstract: In order to unpack and analyze the data received by computer from Wireless Sensor Network(WSN),a WSN test platform was designed.Based on the newest embedded operation system TinyOS-2.x,the wireless communicating mechanism was studied by recomposing sound code of wireless data transceiver module.The key techniques of message packets transmission,the framework of TinyOS,the running mechanism and communicating mechanism were introduced.Test results showed that:① the data sampled by sensor nodes was packed as MAC payloads and transmitted to base station node by RF;② the MAC packet was then repacked as serial message payload and sent to upper computer by UART.It were helpful for developing applications of wireless sensor network.

Chaos-Based Weak Signal Detection Approach via Duffing Oscillator

Abstract: The chaotic character of Duffing oscillator is analyzed,and the Melnikov method of determining chaotic threshold of Duffing oscillators is discussed.The principle of weak signal detection based on the change of phase trace is described,and the influence of noise to the system status in the chaos detection process is also studied.Simulation experiments show that the oscillator is sensitive to the small signal having the tiny frequency difference with the referential signal and immune against the random noise and interference signal having larger frequency difference with the referential signal.The application of the oscillator to weak signal detection is feasible.

Image Encryption Scheme Based on Cat Map and Lu Chaotic Map

Abstract: Chaos is widely used in image encryption because of its high sensitivity to initial conditions and parameters and its stochastic series. Classical Arnold cat map can change the position of image pixel points through iteration, but these pixel points will return to the original position after iterating many times. So it will bring some dangerous to the system. The shortcoming can be avoided by using Arnold cat map and Lu chaotic map, and it can attain the purpose of confusion and diffusion. Through theoretical analysis and simulation, the method was proved to work well.

Research on ZMP theory Applied to the Gait Control of Biped Walking Robot

Abstract: The special relationship between the ZMP point and the barycenter is used to construct barycenter model to checkout the action data of the robot in the problem of gait control of biped walking robot.Meanwhile,the action of robot is divided into some action element,namely the action database. More complex actions can be constructed based on the database.This control method is proved feasible through constructing complex action such as stepping.

Design of a Video Process System Based on Analysis of Signal Integrity

Abstract: The problem of signal integrity arises in the result of the signal reflection and crosstalk in the design of High Speed System.MMSP2 is a chip of high performance in the process of video.The design method of High Speed System must be adopted in the design of system based on MMSP2,in order to reduce the problem of signal integrity(reflection,crosstalk,etc.) as possible.HyperLynx is a powerful simulation tool in signal integrity of high speed circuit.The potential problem of signal integrity can be resolved by the simulation of signal integrity with HyperLynx before the manufacture of Printed Circuit Board.

Design of Full-Color-Large-Screen LED Controller Based on FPGA

Abstract: This paper presents a novel design of a full-color ultra-huge-screen LED display controller. The controller constructs with gamma adjustment module, interlacer module, control signal output module and others based on FPGA. It has 128128 pixels and 12 bit gray levels in red, green and blue respectively, and it can approach a full-color, 1 024768-resolution and high field frequency LED display using controllers array. Experiments prove that this system has the merits of fine resolution, simple and compact structure, high reliability and expansibility.

A New Modified Method Based on Wavelet Threshold De-Noising Functions

Abstract: Partial discharge signal is a kind of weak-signal, and it is easily to interference from the noise around. Wavelet threshold de-noising is an important application of wavelet analysis in partial discharge signal processing. The traditional threshold de-noising methods are hard threshold function and soft threshold function, the application of them in signals processing were successfully, but there were also some places need to be improved, such as soft threshold function losing some useful information of the signal, and hard threshold function is not continuous, and so on. So a new modified method based on wavelet de-noising functions is proposed. In this paper, three different threshold functions, soft threshold, hard threshold and the new threshold functions, were used in partial discharge signal de-noising. From the results of time-domain, frequency-domain, SNR and MSE, the simulation experimental indicates that the new threshold function can offer the best de-noising signal only by changing the variable parameters. More important, the new threshold function is more adaptability than the traditional threshold functions, and these advantages make it possible to construct an adaptive wavelet threshold de-noising algorithm.

A Novel Ultra Broadband Planar Monopole Antenna for UHF

Abstract: A novel simple H-shaped printed planar antenna is designedThe analysis of finite-difference time domain method and HFSS shows the novel printed antenna may obtains favorable performance by adjusting the width of the notch properly and changing the T-shaped feeding configurationThe measurement indicates its bandwidth is greater than 53% at VSWR2 and 288 dB can be obtained on a 015 cm substrate at the center frequencyThis new broadband printed antenna is easy to be integrated with MMIC,and suitable for element of array due to its simple planar configuration