多样化的用户定制线缆

从电力与精确数字、模拟信号,到高压气态和液态介质,如今的用户定制电缆几乎无所不传。线缆制造商们现在可以提供的连接线缆材料可谓五花八门,从多种规格的传统铜线和光纤,到各类软管和导管,甚至包括碳纤维等半导体材料。在对一种专用电缆的设计作出最终决定前,要做一点“外形匹配”的工作。通常要回答的问题包括:“要传输些什么?”、“有什么限制条件?”、“完成任务应该采用何种连接物”。在进行优化的阶段,还要另外考虑使用环境,包括可能存在的电磁干扰、机械应力影响(如扭曲和/或摩擦)、化学和/或高温的损伤。细绞合铜导线在进行大功率…     

THE DILEMMAS OF BUILDING A PROGRESSIVE URBAN COALITION: The Linked Development Debate in Chicago

ABSTRACT: In 1983 Chicago elected its first black mayor, Harold Washington. During Washington's first term of office, his administration not only reordered municipal priorities in such a fashion as to benefit his core, minority voting constituency, but also defined a municipal agenda emphasizing greater attention to neighborhood needs and more open government. In 1984 an important neighborhood coalition, the Save Our Neighborhoods/Save Our City Coalition (SON/SOC), proposed a linked development policy to tap downtown investment for neighborhood projects. Although SON/SOC's proposal was compatible with the Washington neighborhood agenda, this mainly white organization and the Washington administration experienced considerable difficulty in forging a mutually acceptable proposal The linked development debate in Chicago demonstrates the salience of race, class-cultural factors, and alternative approaches to neighborhood mobilization as barriers to the development of progressive coalitions in city politics.     

Computerized conferencing for knowledge acquisition from multiple experts

The increasing complecity of many expert system application areas calls for the integration of the knowledge of multiple experts. The use of multiple experts introduces some interesting new problems during the process of knowledge acquisition. The problems are further complicated when the experts are geographically dispersed or unavailable for face-to-face interactions.

This article discusses the motivations for acquiring the knowledge of multiple experts, the problems related to knowledge acquisition, new issues that arise whens multiple experts interact, solutions that can be brought to bear in building multiple expert systems (particularly when experts are geographically dispersed), and new tools for knowledge engineers to use when dealing with multiple experts.     

美国珠宝评估业与珠宝保险评估

珠宝首饰的评估在美国的发展也是循序渐进的，依据市场与需求进行的，珠宝评估业的规模正在不断扩大，所提供的服务也正在细化，并向更加专业化的方向发展。     

Are all cognitive therapies alike? A comparison of cognitive and noncognitive therapy process and implications for the application of empirically supported treatments.

The definition of an empirically supported treatment (EST) arguably embodies 2 untested assumptions: (a) that different manualized renditions of the same therapy are functionally equivalent and (b) that therapies can be reliably applied independently of therapist, setting, and format. These assumptions were tested as applied to cognitive therapy (CT), using process data from a large multisite study (N=235) that included 3 cognitive and 6 alternative therapies. Although the non-CTs were more variable than the CTs on 2 of 4 dimensions studied (directiveness and emotional arousal), there was considerable variation among the 3 CTs, even when implemented in the current context of rigorous training, manualization, and adherence checks. Results are discussed as related to the assumptions underlying EST criteria. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

3D Motion recovery via affine Epipolar geometry

Algorithms to perform point-based motion estimation under orthographic and scaled orthographic projection abound in the literature. A key limitation of many existing algorithms is that they operate on the minimum amount of data required, often requiring the selection of a suitable minimal set from the available data to serve as a local coordinate frame. Such approaches are extremely sensitive to errors and noise in the minimal set, and forfeit the advantages of using the full data set. Furthermore, attention is seldom paid to the statistical performance of the algorithms.We present a new framework that allowsall available features to be used in the motion computations, without the need to select a frame explicitly. This theory is derived in the context of theaffine camera, which preserves parallelism and generalises the orthographic, scaled orthographic and para-perspective models. We define the affine epipolar geometry for two such cameras, giving the fundamental matrix in this case. The noise resistant computation of the epipolar geometry is discussed, and a statistical noise model constructed so that confidence in the results can be assessed.The rigid motion parameters are then determineddirectly from the epipolar geometry, using the novel rotation representation of Koenderink and van Doorn (1991). The two-view partial motion solution comprises the scale factor between views, the projection of the 3D axis of rotation and the cyclotorsion angle, while the addition of a third view allows the true 3D rotation axis to be computed (up to a Necker reversal). The computed uncertainties in these parameters permit optimal estimates to be obtained over time by means of a linear Kalman filter. Our theory extends work by Huang and Lee (1989), Harris (1990), and Koenderink and van Doorn (1991), and results are given on both simulated and real data.