基于FPGA数字乘法器的设计

数字乘法器是目前数字信号处理中运用最广泛的执行部件之一,本文设计了三种基于FPGA的数字乘法器,分别是移位相加乘法器、加法器树乘法器和移位相加—加法器树混合乘法器。通过对三种方案的仿真综合以及速度和面积的比较指出了混合乘法器是其中最佳的设计方案。     

中频采样中希尔伯特变换器的FPGA实现

介绍了在利用Hilbert变换产生同一时刻I/Q值的中频正交采样中,希尔伯特变换器的FPGA实现方法。利用线性变换以加法器取代乘法器,再利用加数规律不断简化不等长加法器,最终使用FPGA构建若干加法器来实现Hilbert变换。该方案硬件简洁、结构清晰,可满足高速要求。     

基于FPGA数字乘法器的设计

数字乘法器是目前数字信号处理中运用最广泛的执行部件之一，本文设计了三种基于FPGA的数字乘法器．分别是移位相加乘法器、加法器树乘法器和移位相加-加法器树混合乘法器。通过对三种方案的仿真综合以及速度和面积的比较指出了混合乘法器是其中最佳的设计方案。     

模拟加法器和模拟乘法器

模拟加法器和模拟乘法器两者相同点是都有波形变换。两者不同点在于:模拟加法器是线性叠加,输出不产生新的频率。模拟乘法器是非线性变换,输出产生新的频率。通过下面的例子可以深入了解两者。模拟信号的相加和相减如图1所示。也可以扩     

EHMM人眼状态识别算法中的2D-DCT IP核设计

EHMM人眼状态识别算法具有较高的识别率但算法复杂,因此利用SOPC开发平台设计了一种基于行列变换快速算法的2D-DCT IP核以提高处理速度;根据眼状态识别只需取2D-DCT后左上角部分子矩阵数据的特点,对其计算过程进一步优化;并引入了转置存储技术,浮点数乘法通过移位后转化为定点乘法器实现,优化了硬件资源,提高了处理速度;实验结果表明该IP核很好地实现了人眼图像灰度值的DCT变换。     

有效的JPEG2000小波变换VLSI结构设计

基于提升的小波变换算法,提出了一种有效的JPEG2000小波变换的VLSI实现结构。采用了时分复用技术优化结构设计,实现了数据变换的细节分量和近似分量交替输出,以及有效减少了所用乘法器、加法器运算单元和寄存器单元数量,从而有效减少系统占用面积和功耗。该结构实现简单、规则,具有很好的扩展性,非常适合于VLSI设计实现。     

2D-DCT的FPGA实现

设计了采用FPGA来实现2D-DCT的方案,对于其中的关键部分——乘加运算,给出了基于查找表的分布式算法。整个设计节省了资源,提高了运算速度。仿真结果表明,经过2D-DCT变换后的数据与期望值总体上是一致的,这对于数字图像和视频压缩的研究有一定的意义。     

一种高速模(2~n-2~p-1)乘法器的设计

结合余数系统以及模乘法器本身的特点,一种高速的模(2~n-2~p-1)乘法器被提出。得益于剩余范围的扩展和新型的部分积压缩树的采用,该设计相较于传统的模乘法器在关键路径上减少了一个长度为2n的加法器且避免了此类Booth编码模乘法器中复杂的负数修正问题。在90 nm工艺下的综合结果表明,该模乘(2~n-2~p-1)乘法器相较当前的模(2~n-2~p-1)乘法器有10.4%到49%的延迟性能提升。     

基于FPGA的高速流水线浮点乘法器设计

设计了一种支持IEEE754浮点标准的32位高速流水线结构浮点乘法器.该乘法器采用新型的基4布思算法,改进的4:2压缩结构和部分积求和电路,完成Carry Save形式的部分积压缩,再由Catry Look-ahead加法器求得乘积.时序仿真结果表明该乘法器可稳定运行在80M的频率上,并已成功运用在浮点FFT处理器中.     

基于改进的BOOTH编码的高速32×32位并行乘法器设计

采用了一种改进的基—4 BOOTH编码方案,设计了一种高速32×32-b定/浮点并行乘法器。乘法器电路利用CPL逻辑来实现。通过对关键延时路径中的(4:2)压缩器和64位加法器的优化设计,可以在20ns内完成一次乘法运算。乘法器的设计由0.45um的双层金属CMOS工艺实现,工作电压为3.3V,用于自适应数字滤波运算中。     

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     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

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。