复杂性测度分析在电力电子电路故障预测中的应用

在高电压、大电流高频电路的情况下,对电路检测和监视有一定的困难。作者引入了一种新的复杂性分析的方法,利用综合性信号监测电路故障状态。与传统的方法相比,该方法具有快速、简便、经济、安全、非破坏性等优点,可作为电路系统可靠性预测的手段。

高清视频的H．264／AVC帧内预测的ASIC实现

为提高H．264／AVC视频压缩标准中帧内预测的处理速度，满足高清视频的实时编码的要求，本文主要提出了一种基于可重构设计的双通路的模式交替的帧内预测器的ASIC实现方案。在用硬件描述语言（VerilongHDL）实现整个设计的基础上，运用编译仿真工具进行了功能仿真，实验表明，该帧内预测器处理完一个宏块需要720时钟周期，采用时钟频率为200MHz，吞吐量为853Mbit／s，能够满足1920×1080的实时编码要求。

Effect and mechanism of on-chip electrostatic discharge protection circuit under fast rising time electromagnetic pulse

The electrostatic discharge(ESD)protection circuit widely exists in the input and output ports of CMOS digital circuits,and fast rising time electromagnetic pulse(FREMP)coupled into the device not only interacts with the CMOS circuit,but also acts on the protection circuit.This paper establishes a model of on-chip CMOS electrostatic discharge protection circuit and selects square pulse as the FREMP signals.Based on multiple physical parameter models,it depicts the distribution of the lattice temperature,current density,and electric field intensity inside the device.At the same time,this paper explores the changes of the internal devices in the circuit under the injection of fast rising time electromagnetic pulse and describes the relationship between the damage amplitude threshold and the pulse width.The results show that the ESD protection circuit has potential damage risk,and the injection of FREMP leads to irreversible heat loss inside the circuit.In addition,pulse signals with different attributes will change the damage threshold of the circuit.These results provide an important reference for further evaluation of the influence of electromagnetic environment on the chip,which is helpful to carry out the reliability enhancement research of ESD protection circuit.

Recursive bisection placement algorithm with the predicted wirelength

To obtain a better placement result, a partitioning-based placement algorithm with wirelength prediction called HJ-Pl is presented. A new method is proposed to estimate proximity of interconnects in a netlist, which is capable of predicting not only short interconnects but long interconnects accurately. The predicted wirelength is embedded into the partitioning tool of bisection-based global placement, which can guide our placement towards a solution with shorter interconnects. In addition, the timing objective can be handled within the algorithm by minimizing the critical path delay. Experimental results show that, compared to Capol0. 5, mPL6, and NTUplace, HJ-P1 outperforms these placers in terms of wirelength and run time. The improvements in terms of average wirelength over Capo10. 5, mPL6 and NPUplace are 13%, 3%, and 9% with only 19%, 91%, and 99% of their runtime, respectively. By integrating the predicted wirelength-driven clustering into Capo10. 5, the placer is able to reduce average wirelength by 3%. The timing-driven HJ-P1 can reduce the critical path delay by 23%.

一种性能优良的电测数据处理终端

本文介绍了一种无线电信道预测数据处理终端,它采用单片机和微机相结合的方法,利用单片机控制灵活、微机数据处理强的特点,实现了电路电平强度,电路电平快慢衰落特性的自动测量,自动记录。其特点:(1)测量精度高;(2)数据可以现场实时处理,亦可记录保留事后处理,使用灵活方便;(3)可以接收动态范围≤90dB的电压信号。

Life prediction of ZPW-2000A track circuit equipment based on SVDD and gray prediction

Evaluation of the health state and prediction of the remaining life of the track circuit are important for the safe operation of the equipment of railway signal system.Based on support vector data description(SVDD)and gray prediction,this paper illustrates a method of life prediction for ZPW-2000A track circuit,which combines entropy weight method,SVDD,Mahalanobis distance and negative conversion function to set up a health state assessment model.The model transforms multiple factors affecting the health state into a health index named H to reflect the health state of the equipment.According to H,the life prediction model of ZPW-2000A track circuit equipment is established by means of gray prediction so as to predict the trend of health state of the equipment.The certification of the example shows that the method can visually reflect the health state and effectively predict the remaining life of the equipment.It also provides a theoretical basis to further improve the maintenance and management for ZPW-2000A track circuit.

Corona noise model of high-voltage AC transmission lines and engineering applications

In order to predict the levels of corona noise from high-voltage alternating current （AC） transmission lines, the mechanism of corona noise and the corresponding theoretical prediction model are investigated. On the basis of Drnde model, the motion of positive and negative ions produced by high-voltage corona is analyzed, and the mechanism of corona noise is discovered. The theoretical prediction model is put forward by using Kirchhoff formula, which is verified by the well agreement between our result and others＇ , considering the case of three- phase single lines. Moreover, the calculation results show that for both single and bundled lines, the sound pres- sure level of the typical frequency, i.e. twice the power frequency, attenuates slowly and leads to an obviously in- terferential phenomenon near the transmission lines, but the level of the bundled lines is smaller than that of the single ones under the same transmission voltage. Based on the mechanism of corona noise and the prediction model, it is obvious that bundled lines and/or increased line radius can be adopted to reduce corona noise in the practical engineering applications effectively. This model can also provide a theoretical guidance for the high-volt- age AC transmission line design.

基于网间备份路由技术策略对网间业务量溢出支撑的研究

中国法定节假日引发节假日业务量飞速增长的特征越来越明显,通信运营商必需确保节假日网间业务量不会溢出,或者在话务即将溢出的情况下,确保网间溢出的业务量经由备份路由进行疏导,从而确保网间通信畅通。介绍了规范的计算方法,准确计算和预测节假日前增开电路数据。介绍了网间备份路由技术策略并提出了较详细的网络支撑建议,确保节假日业务量不再溢出。