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41.
References: 《计算技术与自动化》2003,22(Z1):54-57
In order to avoid unnecessary damage of electrical equipments and installations,high quality power should be delivered to the end user and strict control on frequency should be made, Therefore, it is important to estimate the power system's harmonic components with higher accuracy. This paper presents a new approach for estimating harmonic component in a power system using secant - fuzzy linear regression method. In this approach the non - sinusoidal voltage or current waveform is written as I linear function. The coefficient of this function is assumed to be fuzzy number with a membership function that has center and spread value. The time dependent quantity is written as Taylor series with two different time dependent quantities. The objective is to use the sample obtained from the transmission line to find the power system harmonic components and frequencies. We used an experimental voltage signal from a sub power station as a numerical test. 相似文献
42.
Biases in social comparative judgments, such as those illustrated by above-average and comparative-optimism effects, are often regarded as products of motivated reasoning (e.g., self-enhancement). These effects, however, can also be produced by information-processing limitations or aspects of judgment processes that are not necessarily biased by motivational factors. In this article, the authors briefly review motivational accounts of biased comparative judgments, introduce a 3-stage model for understanding how people make comparative judgments, and then describe how various nonmotivational factors can influence the 3 stages of the comparative judgment process. Finally, the authors discuss several unresolved issues highlighted by their analysis, such as the interrelation between motivated and nonmotivated sources of bias and the influence of nonmotivated sources of bias on behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
43.
Chenn-Jung Huang Wei-Kuang Lai Sheng-Yu Hsiao Hao-Yu Liu Rui-Lin Luo 《International Journal of Wireless Information Networks》2004,11(3):131-146
In this paper, a routing protocol which utilizes the characteristics of Bluetooth technology is proposed for Bluetooth-based mobile ad hoc networks. The routing tables are maintained in the master devices and the routing zone radius for each table is adjusted dynamically by using evolving fuzzy neural networks. Observing there exists some useless routing packets which are helpless to build the routing path and increase the network loads in the existing ad hoc routing protocols, we selectively use multiple unicasts or one broadcast when the destination device is out of the routing zone radius coverage of the routing table. The simulation results show that the dynamic adjustment of the routing table size in each master device results in much less reply time of routing request, fewer request packets and useless packets compared with two representative protocols, Zone Routing Protocol and Dynamic Source Routing. 相似文献
44.
This paper reports how the study of formal logical reasoning provides insight into more everyday types of reasoning, such as that involved in language comprehension. Both of these types of cognition are thought to involve the use of mental models, and so it is reasonable to think that the cognitive operations needed for formal logical reasoning would be involved in everyday reasoning as well. We focused on three aspects of formal reasoning: (a) the integration of information into a common mental model, (b) the drawing of inferences, and (c) the coordination of alternative possibilities. We were able to show that the integration and inference components were related to narrative comprehension processes, but the coordination of alternative models was not. Thus, there is evidence for some overlap in the mental processes used in formal and everyday reasoning. This further justifies the study of formal logical reasoning as a window into certain types of everyday reasoning. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
45.
The effects of case libraries on problem solving 总被引:3,自引:0,他引:3
Abstract The purpose of the study was to investigate the effects of providing access to a case library of related stories while undergraduates solved ill-structured problems. While solving complex food product development problems, the experimental group accessed experts' stories of similar, previously solved problems; the comparable group accessed fact sheets (expository representation of stories' content); and the control group accessed text selected at random from a textbook dealing with issues unrelated to the stories. On multiple-choice questions assessing processes related to problem solving (prediction, inferences, explanations, etc.), experimental students out-performed the comparable and control groups. Performance on short-answer questions also assessing problem-related skills was not significantly different, in part because of test fatigue. Analysis of interviews identified a number of factors that students used in deciding how to apply their study strategies, including causal factors, grounding phenomenon, grounding in context, and outcomes. 相似文献
46.
Allen Daniel N.; Strauss Gregory P.; Kemtes Karen A.; Goldstein Gerald 《Canadian Metallurgical Quarterly》2007,21(6):713
Hemispheric involvement in reasoning abilities has been debated for some time, and it remains unclear whether the right hemisphere's involvement in problem solving is modality specific or dependent on the type of spatial reasoning required. In the current study, 2 types of nonverbal reasoning abilities were examined, spatial reasoning and proportional reasoning, in 109 patients with cerebrovascular disease that was confined to either the right or the left hemisphere or was diffuse in nature. Results indicated that no lateralizing effects were present based on type of spatial reasoning. Findings are consistent with the suggestion that higher order cognitive processes involved in nonverbal abstraction and problem solving are not strongly lateralized to the right hemisphere but rather are more generally distributed throughout the cortex. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
47.
48.
基于参考点的模糊知识表示 总被引:1,自引:0,他引:1
本文分析了模糊关系模型的知识表示途径,并由此提出基于参考点的模糊知识表示,分析了它与人类记忆经验性知识的相信性,并证明模糊关系模型能以任意精度逼近具有有限个极值点的有界连续函数。 相似文献
49.
本文分析了模糊字符串几种类型和它的表示方法,并给出模糊匹配的算法及C语言的源程序,同时也指出了在文枉编辑器的应用例子。 相似文献
50.
用基函数神经网络实现多阈值图象分割 总被引:1,自引:0,他引:1
本文介绍了一种用基函数神经网络实现多阈值图象分割的新方法。它从函数逼近的角度研究基于灰度直方图的多阈值分割问题,提出了一种模糊反向传播学习算法,采用该算法的高斯基函数网络能够准确检测直方图中包含的子区域和它们的分布函数,而且速度很快。实验表明本文的方法在实际图象分割中是有效的。 相似文献