Pereformance and cooperative thresholds analysis for cooperative MIMO system

In this paper,the bit error rate (BER) performance of cooperative multiple input multiple output (MIMO) system is analyzed and two thresholds for decode-and-forward (DF) cooperative network are propose...     

基于用户关系挖掘的多策略推荐算法

个性化推荐服务为解决网络信息过载问题提供了有效手段。传统的推荐方法大多只关注于如何提高推荐的准确性,而忽略了推荐多样性对用户体验的影响。文章将社会网络用户关系挖掘应用于用户偏好预测及推荐中,提出了一种基于用户关系挖掘的多策略推荐算法。采用信任传播模型挖掘用户间的信任度,计算用户偏好配置文件的余弦相似性获得用户间的相似度,并给出4种将用户信任度、相似度结合的策略,在定义用户偏好预测函数的基础上采用Topn原则为用户给出推荐结果。实验结果表明,文章方法不仅减少了数据稀疏性的影响,而且兼顾了推荐准确性与多样性指标,提高了推荐系统的整体性能。     

Elementary students' participation style in synchronous online communication and collaboration

This research investigated how differently elementary school students participate in synchronous online collaborative learning by analysing their discussions with their partners. Two hundred and seventy-eight Taiwanese students, ranging in age from 11 to 12 years old, were involved in this study. The students were randomly arranged within-class into three-member groups. Each group used a collaborative learning system to discuss and accomplish a group assignment (creating a shared concept map). The textual discussions by each individual student were collected, categorised and accumulated. Cluster analysis was adopted to statistically classify students based on their discussion characteristics. We found that a student, while participating in online collaboration and communication, exhibited a distinct style: less contributing, coordination emphasising, communicative or task-oriented. In addition, students exhibiting the task-oriented pattern and students predominantly showing communicative behaviours were found to have better learning performance and retain more knowledge than students observed to be coordination emphasising or less contributing within group collaboration.     

场地平土和雨水管网的综合优化设计

通过寻求最小土石填挖量的场地标高和坡度设计,在满足土石填挖平衡的基础上,分析了场地平土的优化设计.同时在给定场地坡度的前提下,分析了雨水管网的布置,得出最优的管线布置.其次,将场地平土和雨水管网布置结合起来,在统一考虑场地平土坡度对平土费用和雨水管网布置费用影响的基础上,得出了二者总体费用最小的综合优化模型.最后,通过实例与分步设计方案费用的比较,证实了该综合优化模型的有效性.     

瑞利信道下线性分组码的分集增益研究

比较AWGN信道与瑞利信道的误码性能,研究瑞利信道下分集支数与信息传输可靠性之间的关系。推导线性分组码在瑞利信道下误码率上界的理论表达式,得到分集增益与其最小汉明距离的关系。基于蒙特卡洛法对误码性能进行仿真,并与理论误码率上界进行比较,结果表明线性分组码在瑞利信道下获得的分集增益等于其最小码距。     

差异性视角下的大学理念

思想指导行动，即理念指导实践。当下的大学发展在同一性大学理念的指引下出现了一些问题。通过对同一性大学理念进行反思的基础上提出差异性大学理念，即不同类型、不同层次的大学具有不同的理念。     

基于相似性遗传算法及其在JSP中的应用

提出一种基于个体相似性的改进算法, 当种群的多样性较好时,采用标准的交叉策略;当种群的多样性较差时,根据个体的相似性选择个体配对, 避免相同的个体配对交叉, 减少高度相似个体进行配对交叉的概率, 从而提高交叉操作的效率. 用该改进算法对基准作业车间调度问题（JSP）进行计算,仿真结果表明：该算法优于标准遗传算法.     

差分进化微粒群优化算法-DEPSO

微粒群优化算法是一种新的进化计算技术,具有良好的优化性能,但是对于高维多模态函数,因进化后期微粒多样性的降低导致算法早熟收敛.文章提出的差分进化微粒群优化算法(DEPSO),拓宽了微粒信息传递的途径,增加了微粒的多样性,保证了算法的全局收敛.实验结果表明,DEPSO比PSO有更好的性能.     

论视觉识别系统VIS设计的同一性和差异性原则

视觉识别系统VIS是以企业标志为核心,通过与色彩、文字、图案等视觉元素的有机组合而建立的具备明显识别特征、审美价值和象征意义的符号系统。在VIS基础系统开发时充分贯彻差异性设计理念有利于企业形象脱颖而出,获得社会关注;而在VIS运用系统设计及实施过程中遵循同一性原则,更可以将有限的宣传资源在无限的市场空间内相对集中,通过不断强化而产生足够的形象影响力,实现企业形象塑造的价值。差异性和同一性原则是开发设计与实施VIS的基本原则。     

Addressing Diversity Issues in Play Therapy.

Globalization is upon us, resulting in almost daily exposure to and interaction with highly diverse populations. To practice ethical play therapy, play therapists must become culturally competent. Play therapists are called on both to address cultural issues in therapy and to facilitate children's pride in, and preservation of, their culture. Despite this, the existing literature on cultural competence in psychotherapy has rarely been applied to play therapy practice. The author's goal is to do just that so as to provide play therapists with a model relevant to their work. Play therapists must first fully understand the concept of culture and its potential impact on their own lives, the lives of their clients, and the play therapy process. Second, play therapists need to develop adequate levels of culturally related awareness, skills, and knowledge. Last, they can ensure the work they do is more culturally sensitive and competent by following basic guidelines. (PsycINFO Database Record (c) 2010 APA, all rights reserved)