共查询到20条相似文献,搜索用时 15 毫秒
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Contrary to many previous reports of widespread grazing, most viewers in this study made very limited use of remote control devices (barely one or two RCD operations per half-hour). Comparisons of the separate operations of punching, arrowing, scanning, jumping, inserting, and muting showed that, overall, the most common RCD activity was punching in a specific channel number, a direct substitute for dial turning. Moreover, most activity took place on the hour and half-hour rather than within programs, meaning that commercial avoidance was infrequent and suggesting that industry concerns about radical changes in viewing behavior resulting from remote control use may be overblown. 相似文献
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对MMS业务发展过程中迫切需要解决的技术问题,包括MMS内容如何实现在不同制式、能力的手机终端间的兼容和转换;如何控制具有较高附加值的MMS内容的随意传播,从而保护内容提供者的利益等进行了分析。提出了应优先发展的媒体格式转换、UAP和DRM等几项关键技术。并对UAP和DRM技术进行了进一步的分析和说明。 相似文献
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利用先进成熟的红外遥控技术,在前端机房中建立一个开放式的红外遥控链路,对机房中的各红外电器设备进行统一集中管理,允许用户改变系统中的红外设备类型、数量. 相似文献
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By the 1984 model year, virtually all spark-ignition passenger cars sold in the United States will contain microprocessor-based electronics to meet prescribed emissions and fuel economy levels. Effective implementation of engine control strategies to meet these objectives through the use of electronics, particularly microprocessor-based electronics. depends on a broad knowledge of many diverse engineering disciplines?from basic concepts of emissions control, through microprocessor and semiconductor memory architecture and operation. 相似文献
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在码分多址(CDMA)系统中,功率控制被认为是所有关键技术的核心,可以有效地克服远近效应和多址干扰的影响。提出了一种新的基于最小均方误差(MMSE)多用户检测的分布式功率控制算法。实验结果表明,该算法具有收敛速度快,功率控制效果好的优点,使用该算法可以有效降低系统内用户发射的总功率,同时系统容量也得到一定程度的提高。 相似文献
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运营商相继推出MMS业务 SMS业务取得的巨大成功,使得人们对 MMS业务的发展抱有较高的期待值。从全球 来看,近两年来,MMS业务的开发和商业试 验进程是相当迅速的。如今,不仅欧洲的运营 商纷纷推出了MMS业务,亚太地区的运营商 也非常积极地介入到这个领域。图1显示了 MMS的发展历程。 相似文献
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在简介MMSC交换技术发展的基础上,提出了一个具体的多媒体消息交换系统模型-MMSCⅡ。介绍了其系统组成和体系结构。并结合目前运营商的实际需要给出了MMSCⅡ应用综合解决方案。 相似文献
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随着TD-SCDMA网络建设的不断完善,在3G网络上的多媒体业务有着广泛的应用前景.根据在TD-SCDMA网络中基于WAP协议成功实现MMS(彩信)发送的实例,本文介绍了WAP协议产生的背景及其结构,彩信MMS PDU封装格式,详细说明了客户端与WAP网关的连接、中文字符的编解码、图像格式、SMIL语言应用等关键性问题.同时给出了发送实例中MMS PDU的结构图,清晰的说明了MMS(彩信)发送中的封装格式,并针对相应的问题提出了解决方案. 相似文献
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无线遥控电子记分显示电路可用于几乎所有球类体育竞赛的记分,改变单片机汇编程序能扩展实现计时功能。电路操作简单,电路制作费用低廉,经过实验试用,电路工作性能稳定,记分显示效果良好,特别适合厂矿企业、学校及乡镇运动球场。此外,用此遥控编码、解码集成电路和单片机组合也可设计扩展制作许多实用电路。 相似文献
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为降低家用电器的待机能耗,解决因待机能耗增加而引发的环境问题,适应发达国家强制推行使用节能产品的政策,研制了一款能够应用于电视机的红外遥控节能开关插座。在介绍红外节能开关插座工作原理的基础上,提出了开关插座的硬件电路设计方案,详细论述了检测电路、比较电路、开关插头电路等关键电路,阐述了开关插座的软件设计方案,给出了节能开关插座的设计方法。通过对抽样试件进行的各种测试,提出了智能开关插座完整的定型测试流程,并获得了大量的实测数据,为设计相关节能产品提供了参考借鉴。试验结果和得到的订单情况表明,红外遥控节能开关插座设计获得了成功,具有良好的市场前景。 相似文献
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The objective of technical courses is the transfer of knowledge and know-how to students. In the case of discrete event system courses, it is important for a learner to locally or remotely control real systems (or plants) that are composed of many sensors and actuators. The use of these devices poses several problems. First, it is difficult to adapt them to the student's level (from beginner to expert). Second, these systems are generally designed with industrial components. An error on the control-command design can involve safety problems and breakdowns. In this paper, the authors propose an original solution to solve these two problems. To guarantee the safety of the operators and the equipment, an approach using a validation filter is proposed. It is based on the definition of logical constraints, which should in no case be violated. To adapt the difficulty level, it is proposed to modify the level of automation. For that, the functional dimension of the automation system is modified to adapt the student's level of autonomy. The level of automation is defined by the teacher by means of a functional analysis of the system. To validate the approach, it is applied to an original project with ten-year-old children on a packaging system. The aim of the project is to enable ldquoyoung novice control engineersrdquo to perform their first programmable logic controller program to control the whole system. 相似文献