基于拓扑划分的片上网络快速映射算法

该文针对片上网络建立了以能耗和流量均衡为优化目标的映射模型,提出一种基于拓扑划分的快速映射算法(TPBMAP)。该算法不仅考虑芯片的布局特性从而产生规整的拓扑,还采用虚拟IP核技术修正通信核图以完成IP核和网络节点数不等的映射;通过引入以流量均衡为目标的优化模型同时将通信量大的IP核映射到拓扑边缘区域,有效地降低了网络中心的流量;采用迭代的拓扑划分方法以及将通信量大的IP核映射到网络相邻位置,可快速完成低能耗映射。仿真结果表明,相比现有算法,该文提出的算法在映射速度、全网能耗以及网络中心流量等方面有较大优势。     

IP网络的服务质量讲座 第4讲 IP网络流量与拥塞控制技术

1 流量控制与拥塞控制流量控制指在一个IP网络上,以满足协商好的性能指标以及避免出现拥塞为目标的全部网络行为。拥塞控制指最小化拥塞的程度、范围和持续时间的全部网络行为。流量控制和拥塞控制可以使IP网络资源的利用率得以优化,保护IP网络和进入网络的流量,以实现IP性能目标和服务质量(QoS)承诺。     

NM7010A-LF嵌入式网络通信模块的FPGA设计

嵌入式系统的网络传输往往通过软件来实现,其传输速度很受限制.为此,文中提出了一种新的硬件实现方案.该方案将TCP/IP协议相关函数嵌入8051 IP软核中,然后由加载了8051 IP软核的FPGA来控制硬件网络通信模块NM7010A-LF以实现网络中的数据传输,从而实现整个系统在局域网内和通过局域网在因特网上的数据传输.     

基于SOPC的UART IP核设计与驱动开发及系统移植

设计基于SOPC嵌入式系统的UART IP核,依据UART协议,采用Verilog HDL进行各模块设计,使用ModelSim、Quartus II作仿真验证及综合,结果表明该UART IP核功能正确,稳定可靠。根据Avalon总线接口协议实现UART在系统总线上的挂载,建立SOPC嵌入式硬件系统,进行UART IP核驱动开发。利用超级终端实现嵌入式系统与上位机之间的通信,并成功移植uClinux操作系统,实现对嵌入式系统的高级控制。     

基于FPGA的PicoBlaze嵌入式通信系统设计

研究了应用常量编码可编程状态机(KCPSM)的PicoBlaze嵌入式通信系统设计,通过nrf2401数据传输模块,在Xilinx Spartan 3E FPGA上的实现数据的传输和显示。在研究了系统硬件的原理和功能的基础上,应用可编程状态机对FPGA的PicoBlaze IP核进行设计,利用IP Core对收发模块进行控制,实现了模拟数据和数字数据的通信。     

误码测试IP核的设计

提出了一种误码测试IP核的设计方案,可嵌入通信系统,作为系统自检单元的一部分完成系统的误码测试。通过IP核内置的异步串行接口,计算机可以对IP核进行参数配置,并读取误码数据进行性能分析。文中介绍了误码测试IP核结构和关键技术的实现,最后给出了计算机上测试软件的开发方法。     

一种IP网络多媒体通信系统的设计与实现

文章介绍了IP网络流媒体通信控制的相关技术及标准,基于H.323和RTP协议,运用多线程技术设计并实现了一个多媒体通信系统,并在实验室局域网进行测试,对系统通信流程和通信性能进行了分析.     

基于IP核的多接口LCD控制器的设计及实现

为解决多输入格式视频在同一LCD上显示的问题,设计了一种基于IP核的支持多种视频输入接口的LCD控制器。采用IP核产品搭建系统的框架,系统核心控制CPU采用了Xilinx的MicroBlaze软核,以控制各IP核的初始化以及工作方式,系统对外通信通过串口实现;通过Xilinx的集成逻辑分析仪IP核ILA在线采集输入、中间以及输出数据,验证系统的可行性及数据处理的正确性。最终的实验结果表明,本文设计的基于IP核的多接口LCD控制器能够驱动LCD原屏,并且能够支持多种接口的视频输入,显示画面稳定,满足作为PC输出设备及其他接口视频监视设备的要求。     

基于netfilter/iptables和TC的LAN防火墙设计及流量控制

分析了Linux内核netfilter/iptables模块实现防火墙以及流量控制(TC)模块实现流量控制的原理和基本语法规则,在此基础上,针对小型局域网(LAN)提出了一套网络管理系统。该系统利用iptables实现防火墙及网络IP地址转换功能,并利用基于分层令牌桶队列规定的TC实现流量控制功能。实验结果表明,结合iptables和TC的网络管理系统能够有效保护网络安全,合理限制网络设备带宽,进而保障局域网服务质量。     

基于嵌入式通信网络的数据协调

根据量子密码通信的实际需要,构建了一套嵌入式通信网络,实现动态数据传输。选用Spartan3s 1500MB开发板,采用软硬件协同设计方法,用EDK构建了一个基于Xilinx SOPC的网络通信系统,并设计了高斯随机数IP核来生成随机数,利用该系统可以在两台PC机和FPGA板上进行高速远距离的数据传输,实现量子密码通信中的数据协调。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.