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.     

试论数据挖掘中的遗传算法

本文对数据挖掘进行了概述，阐明了数据挖掘的概念、数据挖掘在商业中的意义。如何进行数据挖掘及数据挖掘流程，提出了数据挖掘技术中的一个重要算法-遗传算法的基本原理以及遗传算法在数据挖掘技术中的地位。提出了基于遗传算法的关联规则的提取方法。文章还给出了用遗传算法进行关联规则挖掘的实例，并讨论了数据挖掘技术所面临的问题和挑战。     

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。     

花岗岩成因研究的若干问题

花岗岩是大陆地壳的重要组成,是地质学研究的重要课题.本文对当前花岗岩研究中的几个重要问题进行了讨论,内容包括：（1）花岗岩的成因分类,（2）花岗岩浆起源的温度与压力条件,（3）结晶分异作用与花岗岩成分变化,（4）花岗岩成因与壳幔演化,（5）花岗岩形成的构造环境等.通过分析认为,高分异花岗岩成因类型的确定是比较困难的,在有些情况甚至不可能准确分类.花岗岩的锆饱和温度和锆石钛温度计可对花岗岩浆形成的温度提供重要信息,但花岗岩浆起源的压力条件确定相对困难.花岗岩主要形成于俯冲带或碰撞造山带后造山的拉张构造背景中,在这两种情况下,挥发份和热的加入可使地壳发生部分熔融而形成花岗岩.本文还对我国近年来花岗岩研究的进展情况做了概要性叙述,并就我国东部中生代花岗岩研究的近期突破问题进行了分析.     

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。     

遗传算法在数据挖掘中的应用研究

将遗传算法应用到关联规则的挖掘，提出采用遗传算法提取关联规则的方法，并讨论遗传算法的编码方法和适应度函数的构造．最后结合一个具体的实例，给出基于遗传算法的关联规则的提取算法．     

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.     

视觉临场感遥控系统在移动机器人中的应用

移动机器人技术研究领域在现代科学技术中一直是多学科相互交叉相互渗透的前沿领域,对它的研究不仅具有深刻的理论价值,而且有广阔的应用前景。本文给出了一种室外智能移动机器人(又称自主陆地车辆)临场感遥控驾驶系统的框架,在此基础上结合这个系统的实际情况较为深入地在相关的领域对控制理论作了探讨。