设计实例designideas级联低压差稳压器、SMPS抑制纹波，保持效率

降压型SMPS（开关电源）能有效地将未稳压的电源转换为稳定的输出电压。但是．输出端会出现由开关而产生的有害纹波和输入瞬变。如将有噪声的电源加在RF功率放大器上．则会在广播频谱中注入寄生信号或调制噪声。模拟系统工程师与RF系统工程师都青睐传统的低噪声电源设计．它包括一个变压器、整流器和滤波器．后面是一个线性稳压器。一只低压差线性稳压器的低输出噪声和高PSRR（电源抑制比）可以确保干净的电源．不会造成对功率放大器输出的干扰。     

On problem transformability in VLSI

The two basic performance parameters that capture the complexity of any VLSI chip are the area of the chip,A, and the computation time,T. A systematic approach for establishing lower bounds onA is presented. This approach relatesA to the bisection flow, . A theory of problem transformation based on , which captures bothAT ² andA complexity, is developed. A fundamental problem, namely, element uniqueness, is chosen as a computational prototype. It is shown under general input/output protocol assumptions that any chip that decides ifn elements (each with (1+)lognbits) are unique must have =(nlogn), and thus, AT²=(n ²log² n), andA= (nlogn). A theory of VLSI transformability reveals the inherentAT ² andA complexity of a large class of related problems.This work was supported in part by the Semiconductor Research Corporation under contract RSCH 84-06-049-6.     

On the machining of glass

A study to examine the feasibility of cutting glass in the same manner as ductile metals was carried out on three types of glass (soda-lime microscope slides, carefully polished specimens of lead-doped flint and fused silica). No success was obtained with fused silica while soda-lime glass showed clear evidence of cutting in a manner similar to ductile metals, but provided variable results with different specimens. The most encouraging results were obtained with the lead-doped flint glass. Using a diamond tool with a semicircular face at a rake angle of –34°, crackfree cuts were produced with widths and depths up to about 100 and 1.6 m, respectively. The chips produced during this machining are tightly curled with a serrated concave side. The results of this preliminary investigation suggest many aspects for further study. However, the essential conclusion is that certain glasses may be machined in a manner similar to ductile metals if the size of the cut is small enough.     

THE BLUE NILE: POTENTIAL FOR CONFLICT AND ALTERNATIVES FOR MEETING FUTURE DEMANDS

ABSTRACT

Despite nearly a century of water regulation projects on the Nile Basin, today Egypt faces a genuine crisis with respect to water supply. The crisis has been brought on by a combination of drought and greatly increased usage by all riparian nations along the Nile. It is highly probable that Egypt will need to search for new sources of water, reallocate existing water supply and reduce demand simultaneously in order to stave off major water shortfalls. It is unlikely that these measures can be accomplished without both internal and external conflict. This paper describes the current state of water supply and usage in Egypt. Further we examine potential sources of conflict over water allocation decisions. Finally, the paper presents a method for evaluating alternative strategies that could be implemented by Egypt to avoid future conflict.     

Relationships of sonification to music and sound art

The definition of sonification has been reframed in recent years but remains somewhat in flux; the basic concepts and procedural flows have remained relatively unchanged. Recent definitions have focused on the objective the important uses of sonification in terms of scientific method. The full realization of the potential of the field must also include the craft and art of music composition. The author proposes examining techniques of sonification in a two-order framework: direct and procedural. The impact of new technologies and historical roots of that work argues that framing this broad topic should be in terms inclusive of scientific method and craftsmanship and art. The expressive use of sonic time-based data flows needs to be refined and expanded. The unexamined territory of how a broad-based population of listeners on a subjective, as well as objective level needs, have to be included in this new field.     

A logical foundation for the case‐based reasoning cycle

Case‐based reasoning (CBR) has drawn considerable attention in artificial intelligence (AI) fields with many successful applications in systems such as e‐commerce and multiagent systems. For the moment, research and development of CBR basically follows the traditional process model of CBR, i.e., the R⁴ model and problem space model introduced in 1994 and 1996, respectively. However, there has been no logical analysis for this popular CBR model. This article will fill this gap by providing a unified logical foundation for the CBR cycle. The proposed approach is based on an integration of traditional mathematical logic, fuzzy logic, and similarity‐based reasoning. At the same time, we examine the CBR cycle from the knowledge‐based (KB) viewpoint. The proposed logical approach can facilitate research and development of CBR. © 2003 Wiley Periodicals, Inc.     

Control of island formation on silicon surfaces using ultra-high-vacuum scanning electron microscopy

In situ scanning electron microscopy has been used to control Au island formation on a patterned Si(111) surface with a periodic array of atomic-step bunches and holes. Liquid phase Au-Si islands were observed to redistribute on the patterned surface by annealing. The islands accumulate at a particular position of the step bunch in each pattern unit. This phenomenon is interpreted in terms of the energetic stability of a droplet on a patterned surface.     

The MMPI and chronic pain.

112 chronic pain patients (mean age 48.4 yrs) completed the MMPI upon entering either an anesthesiologic or a psychiatric treatment program. Pretreatment MMPI performance was found to be successful in predicting patient outcome an average of 20 mo following treatment, with the K (Test-Taking Attitude), Hypochondriasis, Hysteria, and Masculinity and Femininity scales accounting for most of the variance. The strength of this relationship varied as a function of the measure of outcome and type of treatment received. Substantial MMPI differences were found when Ss with only one part of their body in pain were compared with those with multiple pain complaints. Significant MMPI differences were also found in comparisons based on Ss' sex, type of pain (e.g., head vs back), and type of treatment for which was referred (i.e., psychiatric vs anesthesiologic). Clinical implications of the observed MMPI differences are discussed. Results are seen as demonstrating the value of the MMPI as a clinical and research instrument within this population. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Trust, power and interorganizational information systems: the case of the electronic trading community TransLease

This paper focuses on Cap Gemini’s electronic commerce system, TransLease. TransLease is an interorganizational information system (IOS), which facilitates electronic commerce between motor vehicle leasing and repair companies. During our investigation, the system was used by approximately 1000 repair agents working for seven of the UK’s leading vehicle leasing and contract hire companies. This system was originally developed by AT&T and acquired by Cap Gemini in July 1998. At the time of acquisition, the system was seen as being of high strategic value, although it was also seen as underperforming. This paper reports the results of an action research project, which formed one element of the process by which Cap Gemini investigated the former problem. In the paper, TransLease is described as a complex electronic community, dependent upon the existence of symbiotic relationships. As such, the problems that the system users and developers experienced can be attributed to factors that impeded the mutual benefit accruing from participation in the system. The efficacy of the terms of exchange and the degree to which participants mutually benefit through electronic interaction is determined by the complex interplay of a number of relational and organizational factors. The research therefore illustrates the importance of the ‘soft’ organizational issues in IOS management and development, and suggests a conceptual model of the factors relevant in this case. At the time of this study, TransLease was still in the early stages of its life cycle, having only been available in the marketplace for approximately 18 months. During this time, through recognizing the complex problems and issues detailed in this paper, Cap Gemini accordingly redressed the way in which the system was managed and maintained. TransLease is now seen as having matured into a highly successful example of an IOS – a view reflected by its position as market leader in the industry. As this paper will show, the key to improving the existing service has been the emphasis Cap Gemini now places on managing the ‘soft’ aspects of the electronic community.