眼检光学相干层析成像系统及实验研究

眼检光学相干层析 (opticalcoherencetomography)成像技术是一种新型成像方法 ,本文阐述了OCT系统的基本原理、组成、建立了一种相干成像实验装置 ,用该实验装置得到了纵向分辨率为 10 μm的实验结果 ,最后 ,本文给出了OCT眼检系统的实验结果     

周视投影彩虹全息术

本文给出一种可周视观察的投影彩虹全息术,分析了衍射像分离条件,给出了两种实验光路,并作了实验验证。     

时间积分声光相关器相关峰提取的新方法

本文讲述了自行设计的一种新型时间积分声光相关器的原理,并以该相关器实验系统为例,分析了系统的特点,提出一种提取相关峰的新方法,最后给出了实验结果。     

电子技术类课程线上实验教学模式探索

文章介绍了一种远程"真"实验管理平台,提出了一种多维度线上实验教学模式。该平台解决了电子技术实验时间和空间上的限制,弥补了虚拟仿真实验欠缺"真实感"的问题,提高了教师实验管理效率,同时为学员提供了更个性化的纠错辅导和更科学的实验效果评价。多维度的线上教学模式,灵活调整教学方法,更好地培养学员自主学习能力和提升学习兴趣。     

混沌反馈调制语音保密通信系统

在硬件实验研究的基础上,建立一种环形蔡氏电路,简述其工作原理及其特点。在此基础上提出用环形蔡氏电路实现混沌反馈调制的一种语音保密通信方案,分析了该方案的同步原理,讨论了发送端和接收端电路参数匹配情况下的同步收敛特性,设计了硬件实验电路,进行了语音混沌保密通信的硬件实验研究,给出了实验结果。     

基于能力培养的实验设计模式研究

传统基础型实验的设计缺陷,一定程度上制约了实践教学改革的深入。本文提出了一种基于能力培养的实验设计模式。该模式既保留了传统基础型实验内容,又充分体现以能力培养为核心的实践教学理念。教学实施表明,将该模式运用于基础型实验的教学,是一种训练学生基本实验技能和提升实践能力的有效途径。     

基于复杂学习理论的虚拟实验平台开发探究

随着信息技术的发展,虚拟实验平台在教学中的优势日趋凸显。文章分析了现有虚拟实验平台的优缺点,提出用面向复杂学习的4C/ID教学模式指导虚拟实验平台的建构,并设计了一种基于该教学模式的网络化虚拟实验平台的结构架构,对其中的主要功能模块进行了阐述,为探索4C/ID模式的实践提供了一种思路。     

相位平均网络理论及实验的初步探讨

相位平均网络是一种能把多个有相位抖动的脉冲进行相位平均,得到一种特殊脉冲信号的网络。本文对相位平均网络进行了理论分析及实验,并对实验结果进行了分析。     

基于LabVIEW的PN码调制解调模块实现

针对伪随机码在通信传输中不可缺的功能以及其在LabVIEW中没有现成的软件工具包等问题,本文介绍了一种基于虚拟仪器的PN码调制解调实现方法。在LabVIEW8.6软件开发平台下,根据PN码调制解调原理及伪随机码生成的基本思想,设计了一种PN码调制解调实验模块。实验结果表明,该实验模块可以实现对PN码进行幅移键控、频移键控、相移键控3种调制解调功能。该实验模块满足实验技术指标且具有设计简便、成本低、扩展性好等优点。     

仿真与实验完美结合创教学最优化

本人对比了自己所开的两节的公开课,教学内容都是《电工基础》中《RLC串联谐振电路》,而且都选择了演示实验的教学方法来授课,但在选择实验方式上有所不同,而且在教学效果上也有不同,从而引发了关于仿真软件实验教学与实物实验仪器演示教学两种不同实验方式的思考。并进一步对两种实验方式进行了比较分析,想探讨出一种创新、创优的教学模式。     

无线Mesh网络试验床的构建与应用

本文首先叙述了无线Mesh网络国内外研究和发展动态;接着描述了上海交通大学SJTU-Mesh网络试验床的体系结构,包括系统架构、硬件平台和软件结构;然后介绍了试验床的部署与应用情况;最后给出了对未来工作的展望.     

Development of Smart Grid Testbed with Low-Cost Hardware and Software for Cybersecurity Research and Education

Smart Grid, also known as the next generation of the power grid, is considered as a power infrastructure with advanced information and communication technologies (ICT) that will enhance the efficiency and reliability of power systems. For the essential benefits that come with Smart Grid, there are also security risks due to the complexity of advanced ICT utilized in the architecture of Smart Grid to interconnect a huge number of devices and subsystems. Cybersecurity is one of the emerging major threats in Smart Grid that needs to be considered as the attack surface increased. To prevent cyber-attacks, new techniques and methods need to be evaluated in a real-world environment or in a testbed. However, the costs for setting-up Smart Grid testbed is extensive. In this article, we focused on the development of a Smart Grid testbed with a low-cost hardware and software for cybersecurity research and education. As a case study, we evaluated the testbed with most common cyber-attack such as denial of service attack. In addition, the testbed is a useful resource for cybersecurity research and education on different aspects of SCADA systems such as protocol implementation, and PLC programming.     

Addressing Scalability in a Laboratory-Based Multihop Wireless Testbed

The MeshTest wireless testbed allows users to conduct repeatable mobile experiments with real radio hardware under controlled conditions. The testbed uses shielded enclosures and a matrix switch of programmable attenuators to produce multi-hop scenarios and simulate the effects of mobility and fading. Previous work focused on the theory and performance of a single-switch testbed. Connecting more than 16 nodes requires multiple matrix switches and introduces theoretical and practical challenges. In this paper we examine, in theoretical and practical terms, two potential designs for a scalable version of the MeshTest testbed, and identify one design that seems to provide the most promising test environment. For this type of multi-switch system, performance improves a great deal if nodes that are close together in the physical scenario are also connected to the same RF switch. Rather than restrict the mobility of the nodes, we show how software virtualization can be used to migrate running node images from one switch to another to maintain the proximity of the nodes attached to each RF switch and improve testbed performance. We also describe our new testbed control architecture, that is an important part of making MeshTest scalable.     

基于PCI总线的雷达高度表仿真平台设计

介绍了基于PCI总线的雷达高度表硬件仿真平台设计,给出了该平台的整体硬件结构及软件结构,对该平台的具体实现进行了较详细的介绍,分析了该硬件仿真平台,并最终在该平台上实现了LFMCW雷达高度表算法的硬件仿真,体现了该硬件仿真平台在评估具体工程算法可行性中的作用.     

A smart software radio: concept development and demonstration

A testbed system was developed for smart networking radio algorithms. The associated modular software environment and Phase I hardware testbed are described. It provides the framework for the development of advanced processing algorithms, adaptive multirate systems, and operational radio algorithms and modules. Modular software radio technology allows for the insertion of new algorithms, the quantitative characterization of waveform performance, and the separation of the waveform definition from the details of the implementation to enhance portability. The testbed is representative of SPEAKeasy II-class open architecture software radios. The FLIPWAVE spread-spectrum modem invented at the US Air Force Research Laboratory (AFRL) was developed and evaluated using this testbed. The waveform is presented with experimental results. A unique feature of this modem is a new single-channel quadraphase differential RAKE receiver processor, which illustrates the contributions of the testbed toward the flexibility and portability of novel modems     

Verification Platform with ARM‐ and DSP‐Based Multiprocessor Architecture for DVB‐T Baseband Receivers

In this paper, we introduce a new verification platform with ARM‐ and DSP‐based multiprocessor architecture. Its simple communication interface with a crossbar switch architecture is suitable for a heterogeneous multiprocessor platform. The platform is used to verify the function and performance of a DVB‐T baseband receiver using hardware and software partitioning techniques with a seamless hardware/software co‐verification tool. We present a dual‐processor platform with an ARM926 and a Teak DSP, but it cannot satisfy the standard specification of EN 300 744 of DVB‐T ETSI. Therefore, we propose a new multiprocessor strategy with an ARM926 and three Teak DSPs synchronized at 166 MHz to satisfy the required specification of DVB‐T.     

Interprocedural Compiler Optimization for Partial Run-Time Reconfiguration

In this paper, we study the performance impact of dynamic hardware reconfigurations for current reconfigurable technology. As a testbed, we target the Xilinx Virtex II Pro, the Molen experimental platform and the MPEG2 encoder as the application. Our experiments show that slowdowns of up to a factor 1000 are observed when the configuration latency is not hidden by the compiler. In order to avoid the performance decrease, we propose an interprocedural optimization that minimizes the number of executed hardware configuration instructions taking into account constraints such as the “FPGA-area placement conflicts” between the available hardware configurations. The presented algorithm allows the anticipation of hardware configuration instructions up to the application’s main procedure. The presented results show that our optimization produces a reduction of 3 to 5 order of magnitude of the number of executed hardware configuration instructions. Moreover, the optimization allows to exploit up to 97% of the maximal theoretical speedup achieved by the reconfigurable hardware execution.     

基于可编程硬件的虚拟路由器数据平面设计与实现

未来网络体系结构创新和验证亟需建设虚拟化网络实验平台,虚拟路由器作为其中的核心组网设备,其结构和性能决定了实验平台的灵活性和承载能力.本文提出基于并行流水线的虚拟路由器数据平面结构,结合并行包分类和异步多指针轮询调度机制,在同一物理底层上实现了多个相互隔离的并行异构路由器.本设计在可编程硬件上进行了原型实现,并结合商用及软件路由器在真实的网络环境中部署、测试与实验.实验结果表明与传统单流水线结构相比,本设计能以更高灵活性和并行性支持异构的路由器实例独立运行;在逻辑资源开销和延时特性未显著增加的情况下,并行虚拟路由器可以达到与硬件可比的线速转发能力.     

智能存储系统硬件平台和驱动的设计

面对数据爆炸性的增长,数据存储领域面临着前所未有的挑战,传统的存储体系结构存在服务器的单点故障与性能瓶颈,为此,提出了一种全新的基于嵌入式的存储体系构架,分析了其硬件平台的关键点并实现了其系统硬件平台和底层驱动的设计。     

Integrated network experimentation for QoS measurements in opaque MANETs

Integrated network experimentation often combines real nodes with simulated ones, each modeling different portions of the topology, in the same experimental run. They enable new validation techniques and larger experiments than obtainable using real elements alone. Integrated experiments can be particularly useful in testing and validating QoS mechanisms for mobile ad hoc networks (MANETs), when the characteristics of the intermediate wireless network segments are not observable from the end segments, and as a consequence these intermediate segments have to be treated as opaque networks; and also when there is a need to conduct experiments in a real MANET environment at a scale larger than just a few nodes. End‐to‐end QoS assurance for such opaque networks, consisting of admission control and quality adjustment, can be based on techniques for dynamically measuring throughput representing the state of these networks. In this paper, we describe a distributed and hybrid testbed that has been deployed for running large‐scale integrated experiments to demonstrate the efficacy of a measurement‐based QoS solution. The infrastructure for the testbed provides an integrated platform consisting of real nodes running the actual software under test, augmented with a simulated network environment. We define a set of metrics and run experiments to evaluate the effectiveness of the QoS solution as well the performance of the deployed testbed. We propose an alternative architecture that employs a Xen‐based virtualization of the real nodes from the deployed testbed. We compare the performances of the virtualized architecture with the deployed architecture vis‐à‐vis latency and resource utilization. Our goal is to establish benchmarks for running large‐scale experiments on performance and QoS measurements in virtualized environments. Copyright © 2009 John Wiley & Sons, Ltd.