综合基带遥测单元信号同步的实现

本文介绍测控综合基带遥测单元位同步、帧同步方案及实现方法、遥测单元功能，以及位同步、帧同步的作用。     

Turn to the material: Remote diagnostics systems and new forms of boundary-spanning

To learn and adapt, organizations engage widely in Information Technology (IT)-mediated boundary-spanning. This involves making sense of a swath of peripheral information made available by digital means so as to expand local knowledge. Prior research on boundary-spanning has paid scant attention to material differences between IT systems in enabling or constraining such activity. In this article, we argue that material features do matter: features afforded by IT systems have a significant impact on the form and content of boundary-spanning. We analyze material features and related affordances provided by remote diagnostics systems – a family of ubiquitous IT systems. These features allow remote diagnostics systems to collect, store, and continuously analyze data about the state of machinery and related production processes across space, time and organizational boundaries. Organizations use these systems to determine when maintenance intervention is needed, or to improve their production processes. Often, these systems are run by external service providers at remote sites, which become the new ears and the eyes of a focal organization’s production processes. Building on a longitudinal multi-site case study of two organizations, we explore the impacts of remote diagnostics systems on boundary-spanning. We observe that material features afforded by the remote diagnostics led the organizations to change their boundary-spanning in contradictory ways. On one hand, they reinforced existing boundaries. On the other hand, they crossed or cut down others, or created new ones. This suggests that the material features of these systems, when combined with new knowledge creation and sharing practices, within and between the local and the remote sites generate richer, multi-faceted inter-organizational knowledge flows. We surmise that IT’s new material features will continue to significantly shape organizing logics that determine where and when organizational boundaries are drawn and crossed. Future boundary-spanning will increasingly be shaped by socio-technical assemblages brought together by increasingly pervasive IT capabilities.     

Exploring VCR use as a leisure activity

On the basis of a uses‐and‐gratifications perspective, this exploratory study examined the TV viewing and VCR use of a sample of 119 households with VCRs. The instrument developed for use in this study consisted of a TV and VCR diary in which respondents recorded a variety of information related to each viewing (or recording) occasion for 1 week. The results suggest that although the ability to manipulate the broadcast schedule was a valued feature of the VCR, VCR use merely enhanced established patterns of TV viewing rather than significantly altered TV viewing or leisure behavior. The playback function of the VCR represented a primarily solitary activity pursued for entertainment and relaxation. Watching rented movies represented a primarily social activity pursued for entertainment, relaxation, and companionship. An equal number of television programs were viewed alone as were viewed with others.     

Women groups formed in response to public video screenings on rice processing in Benin

When the Africa Rice Center (AfricaRice)¹ introduced improved parboiling technology in Benin in 2006 through farmer-to-farmer video, it enhanced women's creativity and motivation to parboil more and better the quality of rice. Their rice attracted more buyers and fetched a higher price which increased their profits and strengthened the women's social cohesion. The video motivated women to start parboiling as a group and to express group-based requests for credit and training. However, newly established women's groups in villages with strong negative experiences from the cotton sector did not last because of fear and mistrust. The video helped local non-governmental organizations (NGOs) to improve their training methods and strengthened their relations with rural communities and between the women rice processors and input and output markets. Although these NGOs responded by facilitating access to micro-finance institutions, they were unwilling to provide credit to the groups because of past bad experiences. Instead, informal credit suppliers proved more responsive. Rice producers who attended the open-air video shows at the same time as the women rice processors became more willing to sell them rice on credit. We discuss the conditions and challenges of farmer-to-farmer video in creating organizational and institutional changes among service providers and rural entrepreneurs.     

基于对多媒体网络教学系统的构建应用与研究

多媒体教学信息资源的运用,必将引发一场深层次上的教学改革。其中,新型教材体系的建立是这场变革的前提和保障。根据最新的教学大纲编制的电子教材、电子教案、电教教材、电子题库广泛运用于教学全过程,适合于网络传输的网络版多媒体教材在教学中将起到重要作用。     

基于触摸屏的机器人远方控制系统

本文介绍了触摸屏、智能机器人的基本原理，以及二者与单片机系统的接口控制，最后讲述了该系统的应用前景。     

中国音乐电视的发展趋向:商业主义与人文主义的对立统一

面对商业主义与人文主义的悖论,取道中庸以图生存的中国音乐电视,只有让商业主义作其驱动力,人文主义为其提供理想和目标,形成二者相互渗透、相互融汇的对立统一局面,才能共同推动中国音乐电视健康前行。     

高速数字传输中的帧同步提取分析

本文讨论具有帧结构的高速数字流的帧同步提取技术。从帧同步器方案的最佳参数设计出发,以误码性能为主要目标,本文较系统地提出了一套有关帧同步过程的基本概念和分析方法,并导出在各种情况下的统计关系及重要结论。本文还以美国陆地卫星TM数据流为例,特别阐述了复帧结构情况下的帧同步提取及其最佳参数设计。     

高速维特比译码器的设计

本文实现了高速(2，1，7)卷积码的维特比译码器。该译码器针对加比选(ACS)模块采用并行化结构设计，并且在解码器的各个部分，在不影响译码性能的前提下，采用了一系列的简化设计，从而使译码器输出数据的速率达到160Mbps。     

英美中三国远程开放大学教学模式比较研究

本文对英国开放大学多种教学媒体支持的自主学习模式、美国国家技术大学的课堂教学远程传播模式、中国中央广播电视大学的"学导结合"的教学模式进行介绍和比较,并对我国发展现代远程开放教育进行了深入思考。