数字通道传输延迟时间测量方法研究

在集成电路测试领域,传输延迟时间tPD是一个非常重要的参数,其不仅反映集成电路对信号的响应速度,也是集成电路测试系统交流参数测量准确的重要影响因素。详细分析了集成电路测试系统传输延迟时间产生的原因,及其对待测器件交流参数测量结果的影响。提出了基于时域反射技术的集成电路测试系统数字通道传输延迟测量方法,并在泰瑞达J750EX集成电路测试系统上进行了实验验证。通过对实验数据的分析,表明该方法能有效测量数字通道传输延迟时间,提高集成电路测试系统交流参数测量准确度。     

FC网络性能测试与研究

为了研究光纤通道用于航空电子系统互连时的网络性能评价问题,需要采用有效的手段对光纤通道网络性能进行测试。在采用轻量IP上层协议通信的光纤通道网络平台上,提出了一种采用ping-pang算法进行光纤通道网络性能测试的方法。通过测试得到了光纤通道网络平均吞吐量和端到端平均延迟时间曲线,并进行了分析。把测试结果和另一种航空电子系统互连首选协议可扩展一致性接口相比较,通过比较发现：光纤通道传输大数据包时具有低延迟、高吞吐量的特性,适合航空电子互连系统中大数据块的传输。对于光纤通道网络性能测试的结果可以作为网络性能评价的重要依据。     

航空电子FC不同拓扑和服务类的实时性测试

在不同的消息流分布模式下,对光纤通道（FC）各种拓扑结构和服务类进行了性能测试,给出了各种传输情况下的消息延迟和吞吐量随负载的变化关系。通过分析得出结论：光纤通道的交换网络和服务类3分别较仲裁环和服务类2延迟小,最大吞吐量大;FC网络在均匀负载模式下,累积负载为网络最大吞吐量的50%以下时,消息传输具有确定性延迟上限。     

基于JPEG2000算法的图像编码装置的设计

针对遥感图像分辨率的不断提高以及传输通道带宽限制的问题,提出了一种FPGA控制的专用JPEG2000标准算法集成电路的高帧频图像编码装置。原始图像数据通过LVDS接口接收,再经过乒乓缓存后传给压缩编码模块,极大地提高了传输速率。经过实际测试,该装置实现了对高帧频图像高压缩倍数的要求,降低了对传输通道带宽的要求,性能稳定可靠。     

用于片上网络的高速低功耗多轨协议异步通信通道

针对传统片上网络中的通信通道功耗大、吞吐量低的缺点,提出一种用于片上网络的高速低功耗多轨协议异步通信通道,其具有检测完成自恢复的功能.每一级通道单元通过自动检测输出端的信号控制电路正常工作,加入门限门使整个通道单元延时不敏感,低延迟传输模块使前向传输延迟减少为1.5倍门延迟,1/4码的编码方式使电路功耗大大降低.在不同工艺模型和不同温度下对电路的性能和功耗进行仿真测试,结果表明,该通道单元最快可以在2.64GHz的频率下工作,平均动态功耗为1.252mW,可以满足高速低功耗的片上网络应用.     

光纤传输技术在伺服远程测试系统中的应用

远程数据传输是伺服远程测试系统的一项重要研究内容。由于伺服系统在地面测试过程中有大量突发性数据需要进行传输,而且对实时性要求比较高,以往的伺服测试系统使用以太网TCP/IP协议进行数据传输,这种传输方式延迟会很高,最终造成伺服测试系统的实时监测与实际产品的动作严重脱节,无法正常完成伺服系统地面测试任务。为了解决以上问题,对以太网协议数据传输延迟进行了分析,同时对高传输速率的光纤传输技术进行了研究,并将其应用到伺服远程测试系统中,很好解决了以太网数据传输延迟性高的问题。     

8通道示波测试技术及其在高射速火炮研发中的应用

针对目前火炮研发中示波测试技术单台设备通道数少,共用多台设备测试时基不同步、数据不兼容及显示有延时等问题,提出一种DLM型8通道示波测试方法及设备;该示波器采用8通道代替传统4通道,解决了多信号的同步触发、时序延迟、分析展现等难题;从高速捕获到长时间记录,实现了多信号灵活可靠的采集;功能强大、指标先进,具有较高的性价比;多次试验验证表明,应用DLM型8通道示波测试技术,能够解决高射速火炮研发中的多通道、高速捕获、长时间记录及多信号显示等测试难题。     

一种面向片上互连的自适应通道双缓冲延迟模型

随着集成电路工艺的等比例缩小,互连线延迟相对门延迟增加,导致报文在片上网络路由器之间的传输需要多个时钟周期。但是,在基于信用点流控策略中,物理链路中的寄存器在发生拥塞时不能够缓冲报文。因此,本文提出了一种自适应的通道双缓冲结构,能够在发生拥塞时缓冲报文。通过门级电路的设计和分析,根据逻辑努力方法建立了CDB的延迟模型。延迟模型的准确性利用Synopsys时序分析工具Prime Time在TSMC的65nm工艺库下被验证,两者相差不超过一个τ4。结果表明,在32nm工艺下,1mm长的半全局互连线通道双缓冲(CDB)和简单流水线(SPLS)所需要的级数相同。     

随机方法在多受限QoS路由调度中的应用

随着多媒体应用的迅速推广,对网络服务质量提出了更高的要求。多媒体信息传输的实时性要求计算机网络能够保证传输信息所需的带宽、延迟、延迟抖动、信息丢失率等。文章提出了一种新的解决多种限制条件下QOS路由问题的启发式算法。在该算法中,主要采用了网络链路信息预先处理和改进的宽度优先搜索等方法。通过网络模拟器的测试,该算法具有良好的性能指标,能够有效地解决多种限制条件下的QOS路由问题。     

光纤通道航电总线数据采集器设计

光纤通道(fiber channel)网络具有高带宽、高可靠性、低延迟等特性,是新一代综合式航空电子系统统一网络的最佳选择。为了解决光纤通道航电总线试飞测试的需求,在分析光纤通道协议的基础上,研究并提出了适用于飞行试验的光纤通道航电总线数据采集器的设计方案,对其中的关键技术进行了探讨和研究,给出了解决途径,对光纤通道航电总线试飞测试技术研究和应用具有一定的借鉴意义。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.