一种低电压亚阈值CMOS基准电路的设计

利用负反馈技术设计了一款基于CMOS亚阈值MOS器件的低压高性能CMOS基准源电路。基于SMIC 0.18μm标准CMOS工艺,Cadence Spectre仿真结果表明：所设计的基准电路能在0.8V电压下稳定工作,输出380.4mV的基准电压;在1kHz频率范围内,电源噪声抑制比为-56.5dB;在5℃到140℃范围内,温度系数6.25ppm/℃。     

一种工作在亚阈值区的CMOS基准电压源设计

提出了一种在低电源电压下工作的CMOS电压基准源,其基准电路采用工作在亚阈值区的nMOS晶体管和自偏置的共源共栅晶体管组合,该电路基准电流产生部分采用两个负反馈回路,确保了基准电流的稳定性.该电路采用标准的0.5 μm CMOS工艺,用Cadence中的Spectre仿真.在fs工艺角下,27℃时基准电压为1.52 V,在120℃范围内(-20℃～100℃)的温度系数可低至31.33 ppm/℃.     

一种CMOS带隙基准源的设计与仿真

分析了传统带隙基准源的基本原理,并在此基础上一款CMOS带隙基准源电路。该电路基于UMC0.18μm CMOS工艺设计,利用cadence软件进行仿真。仿真结果表明,CMOS带隙基准源稳定输出电压1.22V,该电路在温度从-50-100℃进行扫描,其变化率为10.7ppm/℃,电源电压在1.7V-1.9V范围内发生变化时帯隙基准源输出电压变化很小。     

一种高精度基准源电路

基于90 nm CMOS标准工艺,设计了一种低温漂的带隙基准源电路.一种结构新颖的温度曲率校正电路被采用,作为一级温度补偿电路的曲率校正电路.Hspice仿真结果表明:所设计电压源在温度-20℃～+120℃范围内,平均温度系数约为2.2 ppm/℃,获得了一个低压高精度的带隙基准电压源.     

高精度低温度系数带隙基准电压源的设计

基于0.5μm双层多晶双层铝CMOS工艺,采用共源共栅电流镜结构和基极电流补偿方法,设计了一种新颖的高性能带隙电压基准.结果表明,在温度-25℃～125℃范围,基准电压温度系数为15.3×10-6V/℃,低频时,电源抑制比可达-80db.该电路可做为A/D和D/A转换器中的基准电压源.     

一种高精度高电源抑制的CMOS带隙基准

本文介绍了一种高精度高电源抑制的CMOS带隙电压基准,电源电压3V.该电路的实现是基于0.6um 5V的CMOS工艺.为了达到较高的精度和电源抑制比,电路中采用了一个PMOS电流源做调整管,以保证基准核的电流恒定.仿真结果表明,该基准电路在低频下的电源抑制比可达到-88dB,温度变化范围从-40℃至120℃.时,温度系数只有3.5ppm,输出电压误差为0.65mV.     

一种高精度BiCMOS带隙电压基准源的设计

在对传统典型CMOS带隙电压基准源电路分析基础上提出了一种高精度,高电源抑制带隙电压基准源。电路运用带隙温度补偿技术,采用共源共栅电流镜,两级运放输出用于自身偏置电路。整个电路采用了UMC 0.6um BiCMOS工艺实现,采用HSPICE进行进行仿真,在TT模型下,仿真结果显示当温度为-40℃～80℃,输出基准电压变化小于1.5mV,低频电源抑制比达到75dB以上。     

微功耗CMOS电压基准的设计

本文采用0.18μm标准CMOS工艺,设计了微功耗CMOS电压基准电路。该基准电源电压可低至0.9V,功耗为0.8uA,输出基准电压为0.7V。在-20℃~100℃的温度范围内可获得29ppm/℃的温度系数,在1kHZ和100kHZ可分别获得-34dB和-17dB的电源抑制比。     

基于BiCMOS工艺可修调的高精度低温度系数带隙基准源设计

设计了一种利用电阻比值校正一阶温度系数带隙基准电路的非线性温度特性来实现低温度系数的高精度低温度系数带隙基准源;同时设置了修调电路提高基准电压的输出精度.该带隙基准源采用0.8μm BiCMOS(Bipolar-CMOS)工艺进行流片,带隙基准电路所占面积大小为0.04 mm2.测试结果表明:在5 V电源电压下,在温度-40℃～125℃范围内,基准电压的温度系数为1.2×10-5/℃,基准电流的温度系数为3.77×10-4/℃;电源电压在4.0 V～7.0 V之间变化时,基准电压的变化量为0.4 mV,电源调整率为0.13 mV/V;基准电流的变化量为变化量约为0.02μA,电源调整率为6.7 nA/V.     

一种低压高精度CMOS带隙基准

设计了一种改进的带隙基准电压源,通过采用分段电流补偿的方法,实现了低压高精度供电。研究基于TSMC 0.35μm CMOS 3V工艺基础,重点考虑主要工作温度区域输出电压随温度变化的精度问题。仿真结果表明,该电路可提供低至500mV的低压,实现了高阶电流补偿,在-40℃～+100℃温度范围内其温漂系数仅为3.7ppm/℃,在芯片主要工作温度范围内,输出基准电压最大偏差小于8μV,低频时电源抑制比为-70dB。     

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。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。