基于FPGA的卡尔曼滤波器的设计与实现

采用 FPGA 硬件实现卡尔曼滤波器,解决了采用 DSP 软件方法实现存在的并行性和速度问题。以基于 FPGA 的数据采集系统为硬件平台,根据模块化设计思想,采用 VHDL 编程实现ADS8364芯片控制模块,利用 FPGA 的系统级设计工具 DSP Builder 设计卡尔曼滤波器模块,给出模块的软件仿真结果并完成整个系统的硬件验证。结果证明了设计的正确性,同时表明采用 DSP Builder使卡尔曼滤波器的 FPGA 硬件实现更加简单,速度更快。     

基于优化DA算法滤波器的设计及其FPGA实现

由于传统MAC方法在设计数字滤波器时频繁使用乘法器,导致整个系统运行速率下降,而一般DA算法在设计高阶滤波器时存在查找表规模过大以至于难以实现的问题。提出一种优化的DA算法来克服这一缺陷,为此设计了一个18阶的线性相位结构的FIR低通滤波器,并用Verilog HDL语言在FPGA上实现,在第三方仿真平台Modelsim工具上仿真。仿真结果与MATLAB计算的理论值进行对比,验证了此优化算法的正确性。     

基于FPGA的可编程m序列发生器的实现

本文研究了由线性反馈移位寄存（Linear Feedback Shift Registers，LFSR）生成m序列的原理，并对LFSR电路结构作了改进，利用基于现代DSP技术的DSP Builder软件，设计了一种周期、相位可调的m序列发生器。经调试与仿真，结果表明该方法硬件结构简单、开发周期短，为系统设计或测试带来很大的便利。     

数字滤波器在实时滤除心电干扰中的设计与应用

在医疗电子中的心电(ECG)监护仪的设计中,针对心电信号的特殊信号和干扰频率范围,进行了分析,并且设计了一个基于零极点对消的简单整系数滤波器,该滤波器具有严格线性相位,稳定性能好,利用DSP汇编语言进行算法的实现,提高了计算速度,有效地滤除了干扰。     

FIR数字滤波的FPGA实现

随着数字技术的发展,数字滤波器的功能越来越受到人们的注意和广泛应用,它有精度高、灵活性大等突出特点.FIR数字滤波具有稳定性高,严格的线性相位,能用FFT算法实现等特点.通过FPGA实现FIR数字滤波具有实时性高、处理速度快、精度高的特点.文章先通过MatIab DSP Builder设计出FIR滤波器模型,然后利用Simulink进行模型仿真.再用ModelSim进行功能仿真,最后用Quartus Ⅱ进行时序仿真.仿真结束后下载到选定的FPGA上,在FGPA上实现FIR数字滤波.     

基于余弦调制的二维LP-NPR滤波器组设计

二维滤波器组通常用于图像处理中,而图像子带编码希望滤波器组同时也具有线性相位（LP）特性。提出了一种基于一类新余弦调制系统的二维线性相位-近似完全重构（LP-NPR）滤波器组的设计方法,设计过程分为两个步骤：首先采用Parks-McClellan算法来计原型滤波器,再经过余弦调制能到一系列的线性相位分析和综合滤波器,从而可以构造一维LP-NPR滤波器组;然后利用树状结构来结合两个一维LP-NPR滤波器组,并运用单位模变换,可以得到二维不可分离LP-NPR滤波器组。实验结果表明此方法是可行的,所设计的滤波器组可达到令人满意的重构精度。     

一种抗D/A和A/D变换的音频水印算法

音频水印的许多应用要求水印能在模拟环境中保留下来,这涉及到水印的D／A和A／D（以下简称DA／AD）变换,然而,音频水印抗DA／AD变换尚末引起人们的充分重视,已有的音频水印算法能抵抗DA／AD的很少,文中通过大量的实验,分析并得出了在DA／AL）过程中影响音频水印的主要因素：波形失真和时间轴线性伸缩,并针对这些因素提出了一个基于DWT的抗DA／AD变换的茸音频水印算法,针对音频水印DA／AD变换过程中时间轴上的线性伸缩和因幅值变化与噪声影响产生的波形失真,作者在算法中分别采取了相应的对策：（1）在检测过程中结合同步码蕈定位和线性伸缩恢复来消除时间轴上线性伸缩带来的影响;（2）针对幅值改变,在DWT域采用了基于三段低频小波系数之间能量关系的嵌人对策;（3）自适应调整嵌入强度来满足抗噪声攻击的要求,实验表明,所提出的音频水印算法具有很强的抗DA／AD攻击性能和抗其它各种通用的音频处理和攻击的能力。     

基于DSP Builder的GPS/BD2快捕算法设计与实现

介绍了GPS L1频点和BD2 B1频点并行码相位捕获算法的基本原理。为了提高捕获速度,减少计算量,保证捕获精度,易于电路实现,采用固定位置的平均采样方法改进了捕获算法。在Simulink/DSP Builder环境下设计实现了GPS和BD2卫星的快速捕获电路。仿真和实际测试结果表明,DSP Builder图形化设计环境能够高效地完成改进捕获算法的电路设计,而且算法既能发挥FPGA的并行特性又能降低对资源的要求,设计的电路在保证捕获精度的同时达到了双模双通道数据实时处理和快速捕获的要求。     

基于DSP+FPGA的LFMCW雷达测距信号处理系统设计

为解决计算量大的高精度线性调频连续波(LFMCW)雷达测距信号处理算法难以在线验证的问题,提出一种基于数字信号处理器(DSP)和现场可编程门阵列(FPGA)双核架构的雷达测距信号处理系统方案,并完成了软硬件设计和测距算法嵌入.设计方案以DSP为信号处理核心,FPGA为外围设备控制核心.采用C语言实现了基于相位匹配法的LFMCW雷达测距算法在DSP中的嵌入,采用VHDL语言实现FPGA功能模块.在线测距实验结果表明:各功能模块工作正常,基于相位匹配法的测距算法精度高.     

基于DSP Builder的FIR滤波器设计与实现

针对FIR数字滤波器的基本原理和结构特点,利用DSP Builder软件设计了32阶低通FIR滤波器,对该滤波器的性能进行了仿真,并将设计下载到FPGA中进行了硬件测试,测试结果表明:采用该方法设计FIR滤波器简单易行,可缩短设计进程,设计出的滤波器的性能稳定可靠,达到了预期目标.     

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.