XC9500系列CPLD遥控编程的实现

简单介绍了ＸＣ９５００系列ＣＰＬＤ器件及其系统内编程（ＩＳＰ）性能,接着讲述了ＸＣ９５００系列 ＣＰＬＤ器件遥控编程的实现方法,并重点介绍了在遥控编程系统中应用微控制器（ Ｉｎｔｅｌ ８０３１）实现嵌入式ＩＳＰ的软硬件设计。     

用于FLEX10K系列器件配置的一种改进方案

使用Ａｌｔｅｒａ公司的ＭＡＸ＋ＰＬＵＳⅡ软件对ＦＬＥＸ１０Ｋ系列器件进行设计开发，在硬件调试过程中，若采用由Ａｌｔｅｒａ公司提供的几种器件配置方法，都需要通过一台计算机用电缆对器件进行数据下载，这样显得很不方便。为了弥补传统配置方法的不足，设计了一块小巧的ＦＬＥＸ１０Ｋ器件配置板，通过１０针缆线与电路板相连，加电复位后自动对器件进行配置，配置结束后，即可拔去缆线使配置板脱离，这样就实现了调试中的脱离计算机配置，具有方便、灵活、快速的特点。主要以ＥＰＦ１０Ｋ１０器件为例对此方法进行介绍。     

实现双机间大批量数据高速传送的一种方法

利用双口ＲＡＭ器件作为两台微机系统的接口，实现双机间大批量数据高速传送的方法，介绍了该接口的硬件结构和通信程序的编制。     

基于数据构造的仿真技术及应用

介绍了基于数据构造虚拟原型开发技术的概念及两个关键技术，通过和现有虚拟原型开发技术比较，给出基于数据构造虚拟原型技术的优点。着重分析在计算机虚拟实验系统开发过程中，如何通过数据构造计算机虚拟器件，以及如何利用数据驱动机制通过虚拟器件的数据模型来实现器件的功能、属性，并最终实现整个虚拟实验。     

VXI总线消息基器件及数字多用表模件的设计

本文主要对ＶＸＩ总线消息基器件的基本概念、其支持的通信寄存器的配置及ＶＸＩ总线的通信协议进行了简单的介绍，并通过数字多用表模件的设计来说明消息基器件的实现及通信协议的完成。     

VXI总线消息基器件及数字多用表模件的设计

本文主要对ＶＸＩ总线消息基器件的基本概念、其支持的通信寄存器的配置及ＶＸＩ总线的通信协议进行了简单的介绍，并通过数字多用表模件的设计来说明消息基器件的实现及通信协议的完成。     

用socket实现UNIX网络的数据广播

本文首先介绍了在ＵＮＩＸ系统中，ｓｏｃｋｅｔ通信原理，以及ｓｏｃｋｅｔ常用的系统调用，并在此基础上，给出用ｓｏｃｋｅｔ实现ＵＮＩＸ网络数据广播的一个程序实例。     

一个桌式数据会议系统的原型：多媒体技术的一个新应用

本文介绍一个自行设计和开发的桌式数据会议系统。该会议系统实现于ＵＮＩＸ工作站和ＴＣＰ／ＩＰ网络上，并充分利用了多媒体技术，文中指出了桌式数据会议系统的基本要求和其实现中的技术关键。     

一种基于DSP在线更新配置程序的实现方法

针对系统设计通用化的需求,设计了一种使用FLASH存储器作为数据存储器件,配合微处理器程序,利用复杂可编程逻辑器件（CPLD）更新和配置可编程器件,实现对现场可编程门阵列（FPGA）程序和数字信号处理器（DSP）程序在线更新的方法。本文给出了系统构成和实现途径,并对ALTERA可编程逻辑器件和TMS320C6000系列DSP的加载和系统设计实现进行了较详细的说明。     

用PC机作为XENIX／UNIX系统的仿真终端

本文介绍了以ＰＣ机作为ＸＥＮＩＸ／ＵＮＩＸ系统仿真终端的实现方法。较详细地描述了硬件要求和软件连接的具体实现过程，同时对在不同端口上连接不同型号终端的仿真作了讨论。     

基于MSC1210微控制器的数据采集系统设计

介绍了一种采用MSC1210为微控制器的多通道、高精度的测量数据采集系统的结构及其工作原理。该系统通过MSC1210的24位8通道A／D转换器采集位敏传感器的电压数据，并通过一个串口采集角度传感器的数据，然后通过另一个串口与上位系统进行数据通信，进行数据转存及其复杂计算。MSC1210在集成度和精度要求高的测量系统中的应用将越来越广。     

A high-speed and continuous 3D measurement system

A new system for high-speed and continuous 3D measurement is presented. It is based on the slit-ray projection method. The key component is the image plane constructed by a position-sensitive device (PSD) array that is horizontally un segmented and linear, but vertically numbered. All PSD row elements are attached to their respective analog signal processors. The analog signals are multiplexed and digitized by multiplexers and A/D converters at appropriate sampling intervals and stored in memory. By virtue of this configuration of the image plane, basis data for 3D measurement are acquired during only one scan of the slit ray at high speed in the form of memory addresses and data. Moreover, if we use large capacity and/or dual port memories, we can continuously obtain 3D range data for as many scenes as needed. The trial system has been implemented with a newly designed 128-channel PSD array and has verified our method, enabling us to obtain successive 3D range data at video rates with an error within±0.3%.     

基于DSP的二维PSD信号采集装置设计

基于数字信号处理器(DSP),设计了一种信号采集装置,实现了对位置敏感探测器(PSD)信号的处理.选用TMS320F2812(简称F2812)作为主处理器,利用F2812内部的A/D转换模块,完成对目标信号的采集工作.经过数字信号处理,将数字信号转换为位置坐标信号,最后通过异步串口通信(SCI)传输至上位机.实验证明:装置具有很高的可靠性,具有高速数据采集处理功能.     

Session level flow classification by packet size distribution and session grouping

Classifying traffic into specific network applications is essential for application-aware network management and it becomes more challenging because modern applications complicate their network behaviors. While port number-based classifiers work only for some well-known applications and signature-based classifiers are not applicable to encrypted packet payloads, researchers tend to classify network traffic based on behaviors observed in network applications. In this paper, a session level flow classification (SLFC) approach is proposed to classify network flows as a session, which comprises of flows in the same conversation. SLFC first classifies flows into the corresponding applications by packet size distribution (PSD) and then groups flows as sessions by port locality. With PSD, each flow is transformed into a set of points in a two-dimension space and the distances between each flow and the representatives of pre-selected applications are computed. The flow is recognized as the application having a minimum distance. Meanwhile, port locality is used to group flows as sessions because an application often uses consecutive port numbers within a session. If flows of a session are classified into different applications, an arbitration algorithm is invoked to make the correction. The evaluation shows that SLFC achieves high accuracy rates on both flow and session classifications, say 99.9% and 99.98%, respectively. When SLFC is applied to online classification, it is able to make decisions quickly by checking at most 300 packets for long-lasting flows. Based on our test data, an average of 72% of packets in long-lasting flows can be skipped without reducing the classification accuracy rates.     

Application classification using packet size distribution and port association

Traffic classification is an essential part in common network management applications such as intrusion detection and network monitoring. Identifying traffic by looking at port numbers is only suitable to well-known applications, while signature-based classification is not applicable to encrypted messages. Our preliminary observation shows that each application has distinct packet size distribution (PSD) of the connections. Therefore, it is feasible to classify traffic by analyzing the variances of packet sizes of the connections without analyzing packet payload. In this work, each connection is first transformed into a point in a multi-dimensional space according to its PSD. Then it is compared with the representative points of pre-defined applications and recognized as the application having a minimum distance. Once a connection is identified as a specific application, port association is used to accelerate the classification by combining it with the other connections of the same session because applications usually use consecutive ports during a session. Using the proposed techniques, packet size distribution and port association, a high accuracy rate, 96% on average, and low false positive and false negative rates, 4–5%, are achieved. Our proposed method not only works well for encrypted traffic but also can be easily incorporated with a signature-based method to provide better accuracy.     

基于PSD的水利工程变形监测系统设计及室内检验

摘要:为高精度实现水利工程变形测量,设计一套基于PSD传感器的位置检测系统,该系统把激光器安装在水利工程易出现变形的位置上,通过实时观察照射在PSD表面光斑位置变化,测出水利工程水平方向和竖直方向的微位移?本系统首先对PSD输出的信号进行信号处理,再利用单片机对转换后的四路信号进行位置计算,并用遗传算法与LM-BP神经网络法相结合的模型对PSD进行非线性校正,最后把位置结果显示在数码管和系统界面上。PSD作为新型传感器,分辨力高、信号处理简单、可连续探测光点位置,可代替其他监测设备广泛用于水利工程的变形监测。     

二维枕形PSD信号采集与处理系统的设计

针对二维枕形PSD信号输出特点和工程实践中便携化的要求,基于新型单片机C8051F064和二维枕形PSD S1881,设计了一个二维枕形PSD信号采集与处理系统,并利用液晶显示模块SMG240128A设计了数据显示接口电路,实现了对二维枕形PSD输出信号的实时采集与显示;实验表明该采集系统方案是可行的,达到了设计要求.     

基于PSD技术的控制器两片硬件设计

介绍了以现场可编程系统器件ＰＳＤ５０１和１６位单片机８０Ｃ１９６ＫＣ为核心构成的两片控制器的硬件设计方法。通过一个控制器设计的实例将基于ＰＳＤ技术的微机控制器的硬件设计与传统的以数字集成电路为基础的设计进行比较,研究表明基于ＰＳＤ技术的硬件设计是简化硬件、提高可靠性的有效方法。     

一种基于LabVIEW的相位法PSD微位移测量系统设计

基于相位法的位置敏感探测器(PSD)检测技术较之幅值法具有处理电路简单、检测精度高、抗干扰能力强、环境适应性好等优点.利用二维双面分流型PSD和LabVIEW虚拟仪器平台,实现了基于相位法的PSD微位移测量系统的设计.实验表明:PSD输出信号的相位差和光斑位置具有良好的线性关系,非线性误差小于0.1％.     

Noise Tracking Using DFT Domain Subspace Decompositions

All discrete Fourier transform (DFT) domain-based speech enhancement gain functions rely on knowledge of the noise power spectral density (PSD). Since the noise PSD is unknown in advance, estimation from the noisy speech signal is necessary. An overestimation of the noise PSD will lead to a loss in speech quality, while an underestimation will lead to an unnecessary high level of residual noise. We present a novel approach for noise tracking, which updates the noise PSD for each DFT coefficient in the presence of both speech and noise. This method is based on the eigenvalue decomposition of correlation matrices that are constructed from time series of noisy DFT coefficients. The presented method is very well capable of tracking gradually changing noise types. In comparison to state-of-the-art noise tracking algorithms the proposed method reduces the estimation error between the estimated and the true noise PSD. In combination with an enhancement system the proposed method improves the segmental SNR with several decibels for gradually changing noise types. Listening experiments show that the proposed system is preferred over the state-of-the-art noise tracking algorithm.