基于阈值电压差原理的CMOS电压基准源

设计了一种新型的纯MOS结构电压基准源,提出了一个基于简单偏置电路的电流相加电路,利用该电路中具有与电源电压无关且与环境温度成反比特性的和式电流,改善了PMOS和NMOS阈值电压差电路输出电压的温度性能,提高了电压基准源的精度。     

超高速CMOS动态负载分频器设计及研究

在比较反转触发器(TFF)的各种结构的基础上,给出了一种单时钟信号控制实现超高速分频的电路结构,以及具体设计过程.分频器使用动态负载,输出两路互补信号.采用SMIC 0.18um IP6M CMOS工艺,在电源电压为1.8 V的情况下,仿真实现了工作速度10 GHz(可工作频率范围为1-13.5 GHz)、功耗仅为3.1 mW的二分频器,可用于超高速锁相环、时钟数据恢复设计中.     

一种采用曲率补偿技术的高精度带隙基准电压源的设计

本文设计了采用曲率补偿．具有较高的温度稳定性的高精度带隙基准电压源。设计中没有使用运算放大器．电路结构简单，且避免运算放大嚣所带来的高失调和必须补偿的缺陷。此外电路又采用了内部负反馈回路．使基准电压源工作一个稳定的电压下．从而提高基准电压源的电源抑制比(PSRR)。文中最后给出了此基准电压源的各种性能的仿真波形。     

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.     

一种低电压高性能的运算放大器设计

基于0.18μm CMOS标准工艺设计了一种低电压高性能运算放大器。阐述了具有负反馈的三支路基准电流源、带有正反馈环路增益提高的CMOS源极耦合差分输入级结构电路。基于频率补偿思想,提出一种新型频率补偿方法,能够有效提高运算放大器的系统性能。经版图后仿真表明:该运算放大器在1.2 V电源电压下具有109 d B的直流增益,259 MHz的增益带宽,相位裕度74°,功耗为0.82 m W,能够广泛应用到大多数电路中。     

一种消除失调电压的低温度系数带隙基准电路

提出了一种利用多晶硅电阻的温度系数补偿负温度系数电压实现低温度系数的带隙基准电路,并且引入由二分频时钟控制的CMOS开关,使产生的失调电压正负交替做周期性变化相互抵消。采用BiCMOS 0.35μm工艺设计。仿真结果表明,此方法能够使MOS管在失配10%的情况下降低97%的失配,温度系数可达5.2 ppm/℃。工作电压为1.5 V～3.3 V、工作温度为-40℃～+70℃且工作在1.8 V常温下时,电路的工作电压为1.144 3 V,总电流为29.13μA,低频处的电源抑制比为-70 dB。     

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。     

一种双电源四输入端三电平逆变器

提出了一种由双直流电源构成的四输入端三电平逆变器拓扑结构,并采用三次谐波注入PWM作为调制方法。该逆变器通过前级两个电源和两个Buck变换器为后级电路提供四路电平,不同状态下后级电路工作于不同的三个电平状态;前级Buck变换器可以实现对直流母线电压的调节,有较宽的工作电压范围;采用三次谐波注入PWM调制方法能实现较宽的调制范围、低开关损耗及输出电压电流较少的谐波含量。分析了不同状态下双电源四输入端三电平逆变器工作原理、控制方法,并通过Simulink仿真验证了该结构的正确性和可行性。     

一种新颖的低电压CMOS带隙基准源设计

设计一种新颖的低电压CMOS带隙基准电压源电路.电路采用了适合低电源电压工作的nMOS输入对管折叠共源共栅运算放大器,并提出一种新颖的启动电路.基于SMICO.35μm标准CMOS工艺,Cadence Spectre仿真结果表明:在低于1-V的电源电压下,所设计的电路能稳定工作,输出稳定的基准电压为622mV,最低电源电压为760mV.不高于100KHz的频率范围内,电源噪声抑制比为-75dB.在-20℃到100℃范围内,温度系数20ppm/℃.     

基于准浮栅的低功耗差分运算放大器

分析了准浮栅晶体管PMOS的工作原理、电学特性和等效电路,设计了一种电路结构简单的共模反馈电路(CMFB),实现了一个低压低功耗的差分运算放大器。采用Chrt 0.35umCMOS工艺库,在Hspice下仿真结果表明:在电源电压为1.5V时,运放的增益为74.5dB,单位增益带宽为40.5MHz,相位裕度为650,静态功耗为1.2mW。     

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。