一款专用可编程语音压缩芯片的设计

基于SELP算法模型原理,设计了一款高质量多速率语音专用处理器芯片。芯片使用可重构体系结构和超长指令字系统设计方法,将复杂度高的子程序进行优化,能够显著提高指令并行度。仿真结果表明,在该芯片上实现语音压缩编码算法,执行效率高于相同工艺水平的通用DSP,并保持原有编码质量。该处理器能够实现多种类型的语音压缩算法,可以达到对语音算法的高保密性、低复杂度和易开发性。     

基于ARM的码激励线性预测编解码系统的实现

为了克服单DSP码激励线性预测语音系统通用性差、双处理器系统(ARM和DSP)码激励线性预测语音设计成本高和硬件接口设计复杂及稳定性低等问题,提出使用单片S3c2410处理器芯片实现码激励线性预测语音系统;包括算法分析,系统硬件平台设计和系统软件设计.实验结果表明,在不降低系统语音性能的同时,采用单片S3c2410处理器,能够提高系统通用性和稳定性,降低设计的复杂性和成本.     

基于SPI总线的DSP与音频编解码芯片的接口设计

语音信号处理系统中,DSP与音频编解码芯片存在数据格式与速度不匹配的问题,使接口成为设计的关键。针对该问题提出了一种基于SPI总线的DSP与音频编解码芯片的接口设计方法,介绍了接口的关键组成部分。此方法在FPGA上进行了实现,已应用于SuperV DSP处理器的音频处理系统中。     

基于DSP与TLV320AIC23B的音频处理系统

介绍了基于DSP的音频处理技术,提供采用音频编解码芯片TLV320AIC23和DSP理器实现的音频处理系统的典型解决方案.音频编解码芯片完成模拟音频信号与数字信号之间的相互转换,包括语音信号采集和语音信号发送两部分.DSP处理器则完成对经模数转换后的语音信号在数字域处理的过程.该方案可以充分发挥DSP所具有的灵活性好、处理速度快的特点.     

基于DSP的语音处理和识别系统的实现

设计并实现了一种嵌入式语音处理和识别系统,核心处理器是TMS320VC5402,语音接口芯片是TLV320AIC10,软件模块包括语音的端点检测、特征参数提取、模板训练、测试识别等。系统使用定点DSP实现了浮点DSP运算,提高了预算的精度,扩大了信号处理的动态范围。试验结果表明,该系统对孤立词特定人识别率为98%,系统体积小、成本低、可扩展性好,方便应用于许多特定场合,如:声控玩具,门禁控制等。有很好的市场前景。     

一款可编程语音处理器的设计与应用

为了提高通信系统的保密性,降低制造成本,需要进行专用处理器的设计.该文基于SELP(Sinusoidal Excitation Linear Prediction)算法模型原理,设计了一款高质量多速率语音专用处理器芯片.芯片使用可重构体系结构和超长指令字系统设计方法,将复杂度高的子程序进行优化,能够显著提高指令并行度.仿真结果表明:在该芯片上实现语音压缩编码算法,执行效率高于相同工艺水平的通用数字信号处理器,并保持原有编码质量.该处理器能够实现多种类型的语音压缩算法,使语音算法可以达到高保密性、低复杂度和易开发性.     

嵌入式语音系统中多路通信接口的实现

随着语音业务越来越趋于多样化，传统的DSP技术只能简单地对语音进行处理，不能完全胜任业务的多样性。该文介绍了一种利用通信处理芯片MPC860和DSP芯片TMS320VC5509实现多路实时语音通信的方案，并主要讨论了其关键模块QMC驱动。该方案已经得到了应用，能够较好地满足多通道、多路共听的实时语音业务需求。     

基于DSP的语音滤波器设计实现

本文利用DSP芯片的高速处理能力，设计了一款FIR低通语言滤波器，实现了对语音信号高音部分的滤波。经过实验验证在改善语音信噪比方面有明显改善。     

基于FPGA的CPRS混沌加解密芯片算法设计

为了满足日益提高的通信安全需求,缩短实时加解密处理的时间,提出了一种利用CPRSC～V～,沌伪随机序列)加密算法,实现基于FPGA(现场可编程门阵列)的加解密芯片的算法设计.利用FPGA的并行流水线达到了DSP不能达到的处理速率和实时效果.该系统采用RAM分布式存储方式代替寄存器和case选择语句,减少资源利用率的同时获得最高lOOMbps全双工加解密速率,满足当今对加密芯片越来越高的速率要求.该加密芯片可用于对语音、图像以及视频等的加密.     

基于DSP的嵌入式语音识别系统的实现

设计并实现了一种嵌入式语音识别系统。硬件核心处理器是ADSP2181,语音接口芯片为AD1847。软件模块包括语音端点检测、MFCC求取、动态时间弯折算法、识别结果判定、模板训练等。系统使用定点DSP实现了浮点DSP运算,提高了运算的精度,扩大了信号处理的动态范围。实验结果表明,该系统对孤立词特定人的识别率为98％。它可用于声控玩具、智能家电等,具有较大的市场应用价值。     

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。     

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.     

Editorial: Special issue on recent advances in hybrid control theory and applications

正The demands of a rapidly advancing technology for faster and more accurate controllers have always had a strong influence on the progress of automatic control theory.In recent years control problems have been arising with increasing frequency in widely different areas,which cannot be addressed using conventional control techniques.The principal reason for this is the fact that a highly competitive economy is forcing systems to operate in regimes where     

Information for Authors

正Aim The Journals of Zhejiang University-SCIENCE(A/B/C)areedited by the international board of distinguished Chinese andforeign scientists,and are aimed to present the latest devel-opments and achievements in scientific research in China andoverseas to the world’s scientific circles,especially to stimulateand promote academic exchange between Chinese and for-eign scientists everywhere.     

Enhancing a leaf radiative transfer model to estimate concentrations and in vivo specific absorption coefficients of total carotenoids and chlorophylls a and b from single-needle reflectance and transmittance

The relative concentrations of different pigments within a leaf have significant physiological and spectral consequences. Photosynthesis, light use efficiency, mass and energy exchange, and stress response are dependent on relationships among an ensemble of pigments. This ensemble also determines the visible characteristics of a leaf, which can be measured remotely and used to quantify leaf biochemistry and structure. But current remote sensing approaches are limited in their ability to resolve individual pigments. This paper focuses on the incorporation of three pigments—chlorophyll a, chlorophyll b, and total carotenoids—into the LIBERTY leaf radiative transfer model to better understand relationships between leaf biochemical, biophysical, and spectral properties.Pinus ponderosa and Pinus jeffreyi needles were collected from three sites in the California Sierra Nevada. Hemispheric single-leaf visible reflectance and transmittance and concentrations of chlorophylls a and b and total carotenoids of fresh needles were measured. These data were input to the enhanced LIBERTY model to estimate optical and biochemical properties of pine needles. The enhanced model successfully estimated reflectance (RMSE = 0.0255, BIAS = 0.00477, RMS%E = 16.7%), had variable success estimating transmittance (RMSE = 0.0442, BIAS = 0.0294, RMS%E = 181%), and generated very good estimates of carotenoid concentrations (RMSE = 2.48 µg/cm², BIAS = 0.143 µg/cm², RMS%E = 20.4%), good estimates of chlorophyll a concentrations (RMSE = 10.7 µg/cm², BIAS = − 0.992 µg/cm², RMS%E = 21.1%), and fair estimates of chlorophyll b concentrations (RMSE = 7.49 µg/cm², BIAS = − 2.12 µg/cm², RMS%E = 43.7%). Overall root mean squared errors of reflectance, transmittance, and pigment concentration estimates were lower for the three-pigment model than for the single-pigment model. The algorithm to estimate three in vivo specific absorption coefficients is robust, although estimated values are distorted by inconsistencies in model biophysics. The capacity to invert the model from single-leaf reflectance and transmittance was added to the model so it could be coupled with vegetation canopy models to estimate canopy biochemistry from remotely sensed data.     

Mr. Twinn’s bombes

This article discusses the history and design of the special versions of the bombe key-finding machines used by Britain’s Government Code & Cypher School (GC&CS) during World War II to attack the Enigma traffic of the Abwehr (the German military intelligence service). These special bombes were based on the design of their more numerous counterparts used against the traffic of the German armed services, but differed from them in important ways that highlight the adaptability of the British bombe design, and the power and flexibility of the diagonal board. Also discussed are the changes in the Abwehr indicating system that drove the development of these machines, the ingenious ways in which they were used, and some related developments involving the bombes used by the U.S. Navy’s cryptanalytic unit (OP-20-G).