Surface flattening based on energy model

This paper presents a method for three-dimensional surface flattening, which can be efficiently used in three-dimensional computer aided garment design. First, a facet model is used to present a complex surface. Then, a spring-mass model based on energy function is used to flatten the 3D mesh surfaces into 2D patterns. The surface elastic deformation energy distribution is depicted by a color graph, which determines a surface cutting line. The method presented here can efficiently solve flattening problems for complex surfaces. The accuracy of a developed surface can easily be controlled locally. Thus, compared to earlier methods, this method provides more flexibility for solving CAD and CAM problems.     

Ethnic Enclaves and the Dynamics of Social Identity on the College Campus: The Good, the Bad, and the Ugly.

The effects of membership in ethnic organizations and fraternities and sororities on intergroup attitudes were examined using a 5-wave panel study at a major, multiethnic university. The results showed that these effects were similar for both minority and White students. Membership in ethnic student organizations for minorities and Greek organizations for Whites was anteceded by the degree of one's ethnic identity, and the effects of membership in these groups were similar, although not identical, for both White and minority students. These effects included an increased sense of ethnic victimization and a decreased sense of common identity and social inclusiveness. Consistent with social identity theory, at least a portion of these effects were mediated by social identity among both White and minority students. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Does incorrect guessing impair fact learning?

Taking a test has been shown to produce enhanced retention of the retrieved information. On tests, however, students often encounter questions the answers for which they are unsure. Should they guess anyway, even if they are likely to answer incorrectly? Or are errors engrained, impairing subsequent learning of the correct answer? We sought to answer this question in 3 experiments. In Experiments 1 and 2, subjects read 80 obscure facts (e.g., “Where is Disko Island? Greenland”) and then took a cued recall test. When a subject reported being unable to answer a question, on a randomly chosen half of those questions the computer program insisted upon a guess. Corrective feedback was provided either immediately (Experiment 1) or after a delay (Experiment 2). Forced guessing did not affect subjects' performance on a final test given 1 day later. We extended the investigation to more complex material in Experiment 3. Subjects saw a question (e.g., “Why do ice cubes often pop as they melt in your drink?”) and its answer, but for half of the questions, subjects did not see the answer until they first provided a plausible explanation. On a test administered either on the same day or 1 week later, recall performance was again unaffected by a prior wrong guess. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

基于MATLAB线性规划算法下豫西北地区水资源配置优化分析

针对洛阳豫西北地区水资源规划配置问题,引入MATLAB线性规划算法,研究规划年不同保证率下水资源配置状况.现状年水资源预测供、需量失衡,规划年2030、2035年保证率75％下总供水量分别为2.635亿m3、3.576亿m2,相同保证率不同规划年的地表水资源可供水量为一致,不同保证率下地表水可供总量均为1.838亿m3.利用MATLAB线性规划算法对不同配水方案下进行优化,一般供水方案中最大缺水率为35.9％;多水源联合供水方案中规划年2030、2035保证率50％下总供水量分别为3.0045亿m3、3.623亿m3;水源峰值联合供水下可供水量显著提升,各保证率下缺水率低于10％.论文为地区水资源优化配置研究及智能算法应用提供一定参考.     

Analysis of piezoelectric bulk-acoustic-wave resonators as detectors in viscous conductive liquids

An analytical solution for the resonance condition of a piezoelectric quartz resonator with one surface in contact with a viscous conductive liquid is presented. The characteristic equation that describes the resonance condition and accounts for all interactions including acoustoelectric interactions with ions and dipoles in the solution is obtained in terms of the crystal and liquid parameters. A simple expression for the change in the resonance frequency is obtained. For viscous nonconductive solutions, the frequency change is reduced to a relationship in terms of the liquid density and viscosity. For dilute conductive liquid, the change in frequency is derived in terms of the solution conductivity and dielectric constant. The boundary conditions for the problem are defined with and without the electrical effects of electrodes. Experiments were conducted with various viscous and conductive chemical liquids using a fabricated miniature liquid flow cell containing an AT-cut quartz crystal resonator. The results, which show good agreement with the theory, on the use of quartz crystal resonators as conductivity and/or viscosity sensors are reported.