多载波系统中低复杂度的改进比特和功率分配算法

基于迭代的比特和功率分配机制,提出了一种低复杂度的比特和功率分配算法.与传统的迭代分配算法不同,该算法在每次迭代中只需要比较几个特定的子载波.该方法在保持传统迭代算法性能的前提下极大地减小了迭代分配算法的复杂度.此外,通过选择等功率分配方案作为初始方案加快了算法的收敛速度,进一步降低了算法复杂度.仿真结果表明,提出的改进算法在基本不牺牲系统性能的前提下有效地降低了算法复杂度.     

Nonscience majors learning science: A theoretical model of motivation

A theoretical model of nonscience majors' motivation to learn science was tested by surveying 369 students in a large‐enrollment college science course that satisfies a core curriculum requirement. Based on a social‐cognitive framework, motivation to learn science was conceptualized as having both cognitive and affective influences that foster science achievement. Structural equation modeling was used to examine the hypothesized relationships among the variables. The students' motivation, as measured by the Science Motivation Questionnaire (SMQ), had a strong direct influence on their achievement, as measured by their science grade point average. The students' motivation was influenced by their belief in the relevance of science to their careers. This belief was slightly stronger in women than men. Essays by the students and interviews with them provided insight into their motivation. The model suggests that instructors should strategically connect science concepts to the careers of nonscience majors through such means as case studies to increase motivation and achievement. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 44: 1088–1107, 2007     

浅谈语法隐喻及其实际意义

在语言的实际应用中，人们可以把动词、形容词转化为名词，句子转化为词组。这种变化被称作语法隐喻。Halliday（1985）指出，名词化（nominalization）是语法隐喻的主要来源。结果表明：语法隐喻方式有助于意义的有效识解，有利于认知效果的获得，它增强了语篇的语义联系和关联度。     

儿童认知策略的发展特点

认知策略是个体在解决问题的过程中,运用已有的知识和经验,以期达到目的的智力活动.认知策略的层次性使得其分类方式交叉重叠.儿童认知策略的发展具有以下特征:随着年龄的增长儿童开始产生策略,进而自发使用这些策略,策略使用的有效性也在增加.许多实证研究表明,西格勒的重叠波浪模型符合儿童认知策略发展的特点.     

儿童假扮游戏中的认知技能发展

假扮游戏的出现、发展到成熟伴随儿童的认知发展．儿童需要具备必要的认知技能才能参与假扮游戏,与假扮游戏有关的认知技能主要包括:社会参照、解读意图、分离、符号化假扮、角色扮演等．假扮游戏与儿童认知发展是一个交互作用的过程,作用的起点是假扮行为的出现．     

矛盾的独行者--苏曼殊思想管见

苏曼殊是中国近代社会一位独特的人物,其思想矛盾复杂,始终在出世与入世的痛苦抉择和情与理、僧与俗的无奈彷徨中挣扎,其一生都是一个难解之谜.     

可译性与不可译性的认知阐释

人以“体认”的方式认识世界,认知离不开人的身体经验。语言作为认知的产物和对世界进行范畴化的工具就体现了人的经验。人的生理结构以及所处环境的大致相似性决定了经验和认知模式的相似性,这是翻译中可译性的认知基础。但是不同民族所处具体环境的差异和不同文化背景对人具体认识事物的影响使得不同民族的人对事物认识在语言上有不同的表达方式和思维,这是不可译性的原因。     

Being and becoming a university teacher

This study examined how one academic framed the enablements and constraints to her project of being and becoming an academic. Complexity facilitated reflection in that it provided a visual representation of data, which was used to generate a concept map, which represented as equal all the component parts of her landscape. Five spaces with emancipatory potential to assist the academic in her professional development emerged, namely: communities of practice, academic freedom, position statements, development opportunities and a supportive environment. Rather than suggesting any generalisability in the findings, the authors argue that the significance of this study is theoretical and methodological. Complexity theory has the potential to help academic development practitioners understand the landscapes in which their academics operate, and guide appropriate development opportunities.     

从认知的角度看语言符号的任意性

以索绪尔为代表的一部分语言学家将任意性视为语言的基本特征之一,他们认为语言符号的能指与所指之间的关系是任意的、无理据的。以词为例,利用认知理论分析论证语音与语义之间、词与思维之间存在的必然联系,从而说明语言符号的任意性是相对的。