一种多通道视频编解码技术的设计与实现

针针对多通道视频编解码技术实现较困难的问题,提出了把Linux多线程思想引入硬件视频编解码模块,以解决多通道视频编解码问题.结合现代软件工程思想,将编解码软件模块分为Linux内核层、中间件和应用层三个层次,降低了多通道视频编解码的设计难度,具有很强的实用性和扩展性.将该方法应用于可视IP电话终端实践,验证了该方法的可...     

基于USB接口的多通道数据采集仪设计

采甩USB接口芯片CH372实现USB接口功能,并结合A/D转换等电路,设计出应用于机械振动测试方面的多通道数据采集仪.其硬件电路采用模块化设计,包括CH375的接口、单片机及定时器、A/D转换及多路模拟开关电路.系统软件设计分:单片机程序、USB设备驱动程序和主机应用软件3部分.     

A cooperative CDMA-based multi-channel MAC protocol for mobile ad hoc networks

In this paper, we present CCM-MAC, a cooperative CDMA-based multi-channel medium access control (MAC) protocol for mobile ad hoc networks (MANETs) in which each node has one half-duplex transceiver. The protocol mitigates the multi-channel hidden and exposed terminal problems by using information about channel usage gleaned from overhearing (cooperating) neighbours. By accounting for the multiple access interference, CCM-MAC also addresses the near-far problem of CDMA in MANETs enabling concurrent transmissions on each channel. We provide an analysis of the maximum throughput of CCM-MAC and validate it through simulation in Matlab. We also compare the throughput it achieves to IEEE 802.11, a multi-channel MAC protocol, and a CDMA-based MAC protocol.     

A fuzzy logic approach to detect hotspots with NOAA/AVHRR image using multi-channel information fusion technique

This paper proposes a novel approach to detect hotspots using NOAA advanced very high resolution radiometer (AVHRR) for the Jharia, Jharkhand (India) region. Jharia coalfield in Jharkhand is the richest coal bearing area in India that contains a large number of mine fires which have been burning for several decades. In this paper, a fuzzy based methodology has been applied for the determination of hotspots to Jharia AVHRR images based on a theoretical model that establishes relationship among AVHRR channel 4, channel 5 and different vegetation indices. The algorithm consists of four stages: data preprocessing, multi-channel information fusion, hotspot detection using fuzzy logic approach and validation of result. The most commonly used existing algorithms like contextual algorithms, multi-thresholding, entropy based thresholding, and genetic algorithms have limitation that they need some mathematical model for training in order to get the required result. The employed fuzzy logic approach overcomes this requirement and in addition, it is flexible, tolerant of imprecise data and is based on natural language. The results were compared with the results obtained by ground survey and a good agreement has been obtained between observed and predicted hotspots.     

40Gbps多信道RZ/NRZ码传输色散时频特性分析

采用分步傅里叶法求解信号在多信道系统中满足的耦合非线性薛定谔方程组，建立40Gbps多信道通信系统的传输模型，以该模型仿真分析了NRZ码和RZ码的传输性能，并引入时频分析方法分析信号的传输性能。仿真结果表明，RZ码能量集中，误码率低；在40Gbps通信系统中RZ码对PMD有一定的抑制作用，降低了系统OSNR灵敏度的要求，有利于现在的10Gbps的光纤通信系统速率升级到40Gbps。     

多道γ能谱的精细分析

本文描述一种综合考虑放射性核素中各γ射线之间的由分支比给出的强度比值及相对探测效率进行拟合从而给出最优化结果的解谱方法.同时给出对本底描述的函数.利用该方法进行样品中各放射性核素的含量分析时,可以合并分析步骤,降低误差积累.     

硅多条阵列探测器多路电荷灵敏前置放大器研制

本文简要介绍了应用于阵列探测器特别是硅多条阵列探测器的高密度多路前置放大器和前端电子学的发展现状、工作原理、设计要求和设计思路.同时,介绍了一套新开发的用于硅多条探测器中的48路电荷灵敏前置放大器的电路设计和实际测量结果,它具有低成本、高密度、好于1%的能量分辨和良好的长期稳定性.     

基于CH375多通道USB接口与PC机通信的实现

利用USB接口技术,采用USB模块CH375,在加速器核辐射监测系统中实现了多个探测通道USB接口与计算机通信。给出了CH375与单片机接口电路的原理简图,并详细介绍了实现多通道USB数据传输的上、下位机的程序设计。     

虚拟世界中立体声合成与播放技术研究

研究虚拟世界中多声道立体声合成与播放的简化算法。文中首先分析多声道立体声的合成原理，以及混声效果的评价标准及评价声源对整个声音所作贡献的公式，然后给出多声道立体声实时合成和播放的简化算法，整个算法简单容易实现。