Application of stochastic method to optimum design of energy-efficient induction motors with a target of LCC

For an energy-efficient induction machine, the life-cycle cost (LCC) usually is the most important index to the consumer. With this target, the optimization design of a motor is a complex nonlinear problem with constraints. To solve the problem, the authors introduce a united random algorithm. At first, the problem is divided into two parts, the optimal rotor slots and the optimization of other dimensions. Before optimizing the rotor slots with genetic algorithm (GA), the second part is solved with TABU algorithm to simplify the problem. The numerical results showed that this method is better than the method using a traditional algorithm. Project (No. 601299) supported by the Science Foundation of Hebei Province, China.     

Two-stage evolutionary algorithm for dynamic multicast routing in mesh network

In order to share multimedia transmissions in mesh networks and optimize the utilization of network resources, this paper presents a Two-stage Evolutionary Algorithm （TEA）, i.e., unicast routing evolution and multicast path composition, for dynamic multicast routing. The TEA uses a novel link-duplicate-degree encoding, which can encode a multicast path in the link-duplicate-degree and decode the path as a link vector easily. A dynamic algorithm for adding nodes to or removing nodes from a multicast group and a repairing algorithm are also covered in this paper. As the TEA is based on global evaluation, the quality of the multicast path remains stabilized without degradation when multicast members change over time. Therefore, it is not necessary to rearrange the multicast path during the life cycle of the multicast sessions. Simulation results show that the TEA is efficient and convergent.     

基于C/S和B/S模式的网络考试系统的设计与实现

本文论述了一个基于Client／Server模式与Browser／Server模式相结合的网络考试系统的设计与实现，详细介绍了其系统结构、各系统功能模块及软件设计方法。     

Expertise,inhibitory control and arithmetic word problems: A negative priming study in mathematics experts

Solving arithmetic word problems such as “Mary has 25 marbles. She has 5 more marbles than John. How many marbles does John have?”, in which the relational term (more than) interferes with the arithmetic operation (subtraction), relies in part on the ability to inhibit an overlearned ‘add if more or subtract if less’ heuristic in children, adolescents and adults. Here, we used a negative priming (NP) paradigm to investigate whether experts in mathematics need to inhibit this heuristic when solving this type of arithmetic word problem. We found NP effects in experts in mathematics, but with a smaller amplitude than those in non-experts (N = 40). We replicate these results in a second experiment (N = 62) in which we matched experts and non-experts on general intelligence and inhibitory control ability. This suggests that experts also need to inhibit the ‘add if more or subtract if less’ heuristic to solve such problems but were more efficient at inhibiting the heuristic than non-experts.     

凸函数的一个性质及其应用

从凸函数的一种定义出发,推导出凸函数的一个性质定理;将该性质定理中的凸函数代入某些具体函数,就会得到许多很有用的不等式。     

阶差数列的几个性质及其应用

等差是等差数列最核心的本质特征.高阶等差数列(或称n阶差数列)是等差数列的普遍形式,一阶等差数列是n阶差数列当n=1时的特例.以往所见关于等差数列的讨论,大多围绕其一阶情况展开.有些常见的关于等差数列的定义也仅仅适用于一阶条件的假定,不能确切描述等差数列的高阶(二阶及以上)情况.本文研究高阶等差数列及其差分性质,以及在数列的通项公式和前项和的作用.     

The 2004 Bower Award in Science presented to Seymour Benzer

Seymour Benzer was chosen for founding the field of neurogenetics, and for his seminal discoveries of the genetic basis of behavior. His pioneering studies made it possible to begin to acquire key information necessary to understand the human brain.     

一种改进的遗传算法

为了提高标准遗传算法的搜索能力,在每一代的群体更生中,群体个体不是全部来自交配池中杂交和变异产生的个体,而是取其中的一部分,另一部分来自于父本代群体,这两部分一起构成下一代群体。本文提出了一种改进的遗传算法,实验结果表明,改进的遗传算法比标准的遗传算法效果要好很多。     

一种求解整体最优效率行为模型的遗传算法

整体最优效率行为模型是基于满足最低期望投资产出和最高投资额的约束,以整体效率最优为目的的一种数学模型。阐述了求解该模型的一种改进的长模式遗传算法,将各个投资活动的效率进行排序,并引入贪婪策略修正各个染色体,采用三种再生算子进行求解,结果表明改进的长模式遗传算法有效。