电视信号的数字化及其实现

数字电视系统中,电视信号的产生、处理、记录、传送和接收均使用数字信号.本文阐述了模拟电视信号数字化处理的方法和步骤.     

关于加强高职生人文素质教育的思考

高职教育的培养目标决定高职生应具备职业技术素质和人文素质,加强高职生人文素质教育关系到高职校的生存和发展,是培养高职生健全人格、创造性思维、文明意识的需要.确定“以人为本“的教育理念、提升校园文化品位、提高教师的人文素质是加强高职生人文素质教育的有效途径.     

Evaluation of Multicomponent Measuring Instrument Reliability in Complex Design Studies

A latent variable modeling approach to evaluation of scale reliability in complex design studies is outlined. The procedure is readily applicable in empirical research for the purpose of point and interval estimation of reliability of multicomponent measuring instruments in the presence of probability sampling and possible nesting within higher order units. The method can be used to aid scale construction and development efforts in large-scale studies of substantially heterogeneous populations. The described approach is illustrated with data from an international educational survey.     

单位冲激函数δ(t)的广义定义及其特性分析

普通函数对单位冲激函数的定义是不严格的，本文用广义函数对其进行科学的定义，并在此基础上分析单位冲激函数的特性，单位冲激函数在信号分析和系统分析中有着极为重要的地位．     

大规模高速IP网络分布式抽样测量模型

分布式被动测量是研究网络行为的一个重要手段，为了获得分布式协同处理流量信息，要求分析的测量点能抽取同样报，为了能估计流量总体统计属性，抽样样本需要具有统计随机性，为此，章提出分布式掩码抽样测量模型处理高速网络流量，其核心是确定合适的抽样掩码匹配位串，对CERNET主干网络流量IP报头各字段的位熵和位流熵进行分析，结果表明标识字段16比特适合于抽样掩码匹配字段，使用测量数据分析基于标识字段抽样模型的随机性和抽样样本的统计属性，实验进一步验证了所提出的模型具有良好的抽样性。     

Introducing the DYNAMICS framework of moment-to-moment development in achievement motivation

This article introduces a new theoretical and psychometric framework describing moment-to-moment development and inter-dependencies of achievement motivation in terms of the situated expectancy-value theory, by introducing dynamical systems concepts into this line of research. As a first empirical example of a study using this framework, we examined whether task values, costs, and success expectancies measured in a learning situation (time point t) predicted themselves and each other at the next situation (t + 1; 27 min later) within a weekly university lecture.Situational task values, expectancies, and costs were assessed using the experience sampling method in 155 university teacher training students during weekly lectures for one semester, with three surveys during each weekly lesson. Data were analyzed with multilevel cross-lagged structural equation models.There were significant auto-regressions from one learning situation to the next in success expectancies and effort costs, but not in intrinsic, utility, or attainment value nor emotional or opportunity costs. There were no significant cross-lagged effects from one situation to the next in any of the measured situated expectancy-value components.As a framework to integrate dynamical systems concepts into the research on situated learning motivation, we expect the proposed DYNAMICS framework to have a substantial impact on further theory development.