馈线保护中双口RAM的DSP与ARM9双CPU系统接口电路设计

介绍了DSP和ARM9双CPU经双口RAM的接口电路设计。在馈线保护中,采用DSP＋ARM9的双CPU结构,两者之间采用双口RAM进行数据交换。考虑到馈线保护的实时性和可靠性,对双口RAM选用了中断仲裁方式。设计了双口RAM、DSP和ARM9三者之间的硬件接口电路,同时还对三者地址值的分配关系进行了阐述。该接口的设计为牵引变电所馈线保护系统的需求打下了一定基础。     

DSP和FPGA的双核并行通信方法设计与应用

为解决雷达信号处理系统双核通信问题,设计了两种DSP和FPGA之间的并行通信方法,分别通过DSP的外部接口XINTF访问FPGA内部FIFO和双口RAM,利用DSP的读写使能信号作为FIFO和RAM的读写时钟信号.通过对两种并行通信方法进行对比分析,指出雷达信号处理系统中双核通信应该采用DSP和FPGA内部FIFO的方法.     

光纤通信中双口RAM的研究与应用

为了实现高速的数字光纤通信中的大量数据存储和时钟匹配,提出了在光纤通信系统中应用双口RAM对数据进行处理的方案,并详细讨论了双口RAM在FPGA中的实现过程,最终给出了双口RAM的时序仿真结果,并在光纤通信系统中进行了实验验证;结果表明:在光纤通信中应用双口RAM,重塑图像时钟,明显地消除了时钟的毛刺及抖动现象,增强了时钟的稳定性,降低了传输系统中各部分对信号数据及时钟的干扰,提高了数据传输的有效性,同时纠正了双口RAM读写不同步的情况。     

双口RAM在多CPU小卫星综合电子计算机中的应用

结合小卫星综合电子系统可靠性、实时性及数据共享的特点,分析双口RAM芯片的特性,提出了基于双口RAM的多CPU架构星载综合电子计算机应用设计方案;设计用双口RAM实现多CPU之间高速、可靠的并行数据通信和共享,使整个系统软硬件设计简单,数据充分共享,可靠性较高;给出基于双口RAM多CPU架构综合电子计算机的应用实例和实验分析,实验结果表明,该系统运行稳定可靠,具有很高的实时性和数据处理能力。     

应用于安全计算机的双口RAM数据通信方法

轨道交通行业中的三取二安全计算机,使用双口RAM进行数据通信,不仅要考虑数据访问冲突、通信速度,还必须考虑数据的正确性和可靠性。针对这些要求,提出了一种基于角色轮换和自检技术的双口RAM数据通信方法,能够高效、安全地完成双口RAM流水线作业。实际项目应用结果显示,该方法可以避免数据访问冲突,提高数据通信速度,并保证数据的安全正确性。     

CAN智能适配卡的设计方案

本介绍了发电机状态监测仪中CAN智能适配卡的功能和硬件组成,详细讨论了ISA总线及单片机对双口RAM的地址空间的分配。针对ISA总线和卡上单片机同时对双口RAM读写数据时的仲裁问题,提出了一种硬件判优的实现方法。并对适配卡的软件设计进行了总体上的阐述。     

基于CPCI总线的PMC载板设计

设计了一种基于CPCI总线标准的PMC接口载板。载板以FPGA为核心,集成了CPCI接口模块和DPRAM(双口RAM)模块,CPCI接口模块采用FPGA+PCI IP核(软核)解决了系统集成的问题,DPRAM模块为系统提供了数据缓存功能。环回测试和中断测试解决了在没有子卡PMC模块的情况下,读写、验证DPRAM空间数据和测试中断响应的问题。此外,还支持子卡PMC模块后出线到CPCI总线。调试结果表明,该载板在嵌入式实时操作系统VxWorks下可以稳定运行,正确地读写DPRAM空间的数据,及时地响应中断,满足了对载板的性能需求。     

基于双CPU的切换及控制系统设计

针对重要系统可靠性要求,特设计了一种双CPU控制系统。在该系统中,两个CPU彼此独立运行,可以自动或手动实现双机的主辅切换,只有主CPU能正常读写外部RAM数据和控制输出。     

嵌入式CCD图像数据采集系统设计

为了满足嵌入式机器视觉后续图像处理的需要,结合高速DSP和FPGA的特点,设计了一套面向嵌入式机器视觉系统的图像数据采集系统.充分利用FPGA内部异步FIFO资源作为数据缓冲区,将异步FIFO数据以TMS320DM642的PDT方式写入数据SDRAM.当SDRAM接收一帧图像可以直接用DSP进行图像处理.DSP读写SDRAM速度高达150 MHz,PDT传输方式不占用DSP CPU时间,不影响图像处理速度.该系统具有电路结构简单、数据传输实时性好和易于升级等优点.     

通信数据同步中基于FPGA的一种有限任意长FIFO的生成办法

FIFO在数据缓冲和信号同步、交换等领域都具有重要的作用.由于FPGA大规模集成可编程逻辑单元,利用FPGA中BlockRAM多样的寻址特性,在FIFO的使用中FPGA具有大然的优势.本文给出了一种基于FPGA实现任意长度FIFO的办法,利用双口RAM分别编址的特性并行读取以模拟FIFO.该方法已应用在实际的通信系统中...     

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.