基于CPLD的HDB_3编码通信模块设计

HDB3码是一种线路传输码,使用相当广泛,其传输码型是基带传输系统中经常采用的。HDB3码具有无直流分量和低频分量小,干扰能力较好和方便提取时钟抗等优点。本文阐述了HDB3码编码电路的基本原理,在QuartusⅡ软件平台上,对于设计HDB3码编码电路利用复杂可编程逻辑器件,并进行了编码和波形仿真。     

基于CPLD的辨向细分电路设计

辨向细分电路在工业控制中有重要的现实意义,根据电路的特点提出了一种用复杂可编程逻辑器件(CPLD)实现辨向细分电路的方法.CPLD是一种具有丰富的可编程I/O引脚的可编程逻辑器件,具有在系统可编程、使用方便灵活的特点;不但可实现常规的逻辑器件功能,还可实现复杂的时序逻辑功能.因此该方案具有成本低廉、设计灵活和保密性强等特点.     

RS+交织+卷积码级联纠错的FPGA实现

为了提高编解码速率，更好地满足实时收发系统的要求，本文提出了采用由纯硬件电路构成的现场可编程逻辑门阵列（Field Programmable Gate-Array，FPGA）取代CPU系统的纠错码策略．该策略先把RS（Reed Solomon）、交织、卷积编解码分别模块化，然后通过端口映射方式对它们进行逻辑组织以实现整个编解码的级联．分析表明，用FPGA构成的纠错码系统不仅使电路大大简化，稳定性得到极大提高，而且可编程逻辑器件的高智能化使整个系统的设计、调试周期大大缩短．     

RS+交织+卷积级联纠错码的FPGA实现

为了提高编解码速率，更好地满足实时收发系统的要求，本文提出了采用由纯硬件电路构成的现场可编程逻辑门阵列（Field Programmable Gate-Array，FPGA）取代CPU系统的纠错码策略．该策略先把RS（Reed Solomon)、交织、卷积编解码分别模块化，然后通过端口映射方式对它们进行逻辑组织以实现整个编解码的级联．分析表明，用FPGA构成的纠错码系统不仅使电路大大简化，稳定性得到极大提高，而且可编程逻辑器件的高智能化使整个系统的设计、调试周期大大缩短．     

基于CPLD的卷积码编解码器的设计

卷积码是一种性能优良的差错控制编码。本文阐述了卷积码编解码器的基本工作原理,在MAX PLUS2软件平台上,给出了利用复杂可编程逻辑器件设计的(2,1,6)卷积码编解码器电路,并进行了编译和波形仿真。综合后下载到复杂可编程逻辑器件EPM7128SLC84-15中,测试结果表明,达到了预期的设计要求。     

基于GPS的IRIG-B直流码编码器设计

以CPLD可编程逻辑器件作为主功能芯片,设计了IRIG-B直流码编码器的总体结构.采用状态机解析GPS码流的时间信息,用VHDL硬件描述语言设计CPLD内部硬件电路,经过编译和仿真得到正确的的IRIG-B直流码波形.最后,设计并制作了IRIG-B直流码编码器的硬件电路,得到了结构简单、功耗低、经济廉价的IRIG-B编码器.     

远距离高频无源射频IC卡读写系统中双相间隔码的编解码方法

本文介绍了远距离高频无源射频IC卡读写系统中双相间隔码的编解码方法。该方法易于在可编程器件上实现,具有很高的实时编解码速度。     

基于可编程逻辑器件去除电路中抖动设计

随着可编程逻辑器件的发展,在一些电路设计中,电路设计人员普遍的利用可编程器件来设计一些逻辑电路来替代一些老的器件,例如,译码器,时钟发生器等等,同时,利用可编程逻辑器件针对特殊问题设计特殊电路。本文介绍一种应用CPLD解决电路中普遍存在的边沿抖动问题,同时也适用于解决电路中的毛刺问题。     

基于FPGA的HDB3编解码器设计

分析了HDB3编解码原理,提出了一种适合于在现场可编程门阵列FPGA上实现的HDB3编译码器的硬件实现方案,在FPGA上完成了布局布线和时序仿真,最后给出了仿真和实验结果.结果表明该方案切实可行,编译码器运行稳定可靠,已用于实际项目中.     

复杂可编程逻辑器件的设计技术

介绍了复杂可编程逻辑器件（CPLD）的设计技术，重点叙述了复杂可编程逻辑器件架构的设计，关键单元设计技术。采用0．35μm内嵌Flash工艺进行模拟仿真和全定制版图设计，该复杂可编程逻辑器件（CPLD）具有72个宏单元，系统频率可达85MHz，管脚延时可达7ns。     

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.