CAL delivery selection criteria and authoring systems

Abstract  In the past, authoring systems have been used to generate computer-assisted learning materials that have often followed the rather restrictive programmed learning format. A number of innovative ways of using recently developed systems to develop CAL packages that include a wider range of learning activities (access to data bases, simulations, interactive video, etc.) are described. Analogous to the concept of a media selection model, a computer delivery mode selection model is presented as an aid to decision making for designers. This increase in flexibility should broaden the applicability of computerassisted learning (CAL) to a wider range of educational objectives and raise the level of the cognitive emphasis in learning packages, as well as facilitate the implementation of visually appealing materials. The paper also implies a standard of acceptability for authoring systems.     

Adaptive flexibility and maladaptive routines in selecting fast and frugal decision strategies.

Decision routines unburden the cognitive capacity of the decision maker. In changing environments, however, routines may become maladaptive. In 2 experiments with a hypothetical stock market game (n = 241), the authors tested whether decision routines tend to persist at the level of decision strategies rather than at the level of options in strategy selection. The payoff structure of the task was changed after 80 decision trials, rendering a new strategy optimal with respect to expected payoff. Whereas most participants detected the appropriate strategy at the beginning of the task, they tended to retain it even when it was no longer optimal. A hint about a possible change had only a small influence on this maladaptive routine; a monetary incentive had none. Switching to a similar but not identical task relaxed the routine, but not much. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

机场企业内部网络安全策略综合分析

针对企业内部网络系统结构的日趋复杂以及航空运输市场的不断发展,使得企业传统意义下的网络安全措施逐渐暴露出一些潜在的缺陷。为了弥补这些缺陷,在进行可行性分析论证以后,选择了加装防火墙、建立虚拟专用网等技术来保证网络系统的安全。实践证明,该网络安全策略在实际生产运行当中安全可靠、效果显著,同时也使机场企业内部网络系统的安全防范能力有所提升。     

Display modulation by Fourier transform: A preferred method

Abstract— A preferred method for determining the grating modulation of a rear‐projection display using a grating image and Fourier analysis is prescribed. This method is insensitive to spatial image noise and is in better correspondence with the response of the human visual system than is the standard technique. This method is not limited to rear‐projection displays and can be applied to any display technology.     

光盘的出错率分析和研究

本文通过对光存储系统出错特性的分析，研究了一些描述出错特性的主要参数，并且给出了描述出错特性的Ｇｉｌｂｅｒｔ模型及其改进型模型。     

Steady-state weights solution to affine projection algorithm

A new expression of the weights update equation for the affine projection algorithm (APA) is proposed that improves the convergence rate of an adaptive filter,particularly for highly colored input sign...     

海洋石油平台EMS系统的设计与实现

介绍海洋石油平台电力组网的EMS系统设计。针对海上石油平台电网的特点,提出了集SCADA、在线安控及电站综合自动化等功能为一体的EMS系统建设方案,并对EMS的有功功率(频率)控制、电压无功控制、优先脱扣、高周切机、通信故障控制策略进行研究,解决了小电网的安全稳定控制问题。     

基于交流比例积分控制器的单相逆变器

提出一种电感电流、输出电压瞬时值反馈控制和负载电流前馈控制相结合的复合控制策略。在此基础上,研制了一台800W的单相逆变器。实验结果表明,提出的控制策略改善了逆变器输出电压的波形,提高了系统的暂态特性。     

计算机网络安全问题及防范对策

文章简单阐述了当前计算机网络所面临的主要安全威胁,并在此基础上提出了分层控制的方案,建立了不同层次间网络安全的防范措施,希望以此来提高网络安全性。     

服务器虚拟化带来的信息安全风险以及影响策略

服务器虚拟化大大提高了服务器的资源利用率,对客户来说是十分有利的。但是,也带来了一些诸如破坏正常的网络架构、可能致使系统服务器超载等信息安全风险,需要采取一定的影响策略予以解决。能采取的影响策略有:安装兼容性杀毒软件、不间断地进行服务器硬件的容量分析等。