关键词： broadcast disks   mobile computing   broadcast programs   multiple broadcast channels  

摘要： The research issue of broadcasting has attracted a considerable amount of attention in a mobile computing system. By utilizing broadcast channels, a server continuously and repeatedly broadcasts data to mobile users. These broadcast channels are also known as "broadcast disks" from which mobile users can retrieve data. Using broadcasting, mobile users can obtain the data of interest efficiently and only need to wait for the required data to present on the broadcast channel. The issue of designing proper data allocation in the broadcast disks is to reduce the average expected delay of all data items. We explore in this paper the problem of generating hierarchical broadcast programs with the data access frequencies and the number of broadcast disks in a broadcast disk array given. Specifically, we first transform the problem of generating hierarchical broadcast programs into the one of constructing a channel allocation tree with variant-fanout. By exploiting the feature of tree generation with variant-fanout, we develop a heuristic algorithm VFK to minimize the expected delay of data items in the broadcast program. In order to evaluate the solution quality obtained by algorithm VFK and compare its resulting broadcast program with the optimal one, we devise an algorithm OPT based on a guided search to obtain the optimal solution. Performance of these algorithms is comparatively analyzed. Sensitivity analysis on several parameters, including the number of data items and the number of broadcast disks, is conducted. It is shown by our simulation results that by exploiting the feature of variant-fanout in constructing the channel allocation tree, the solution obtained by algorithm VFK is of very high quality and is in fact very close to the optimal one resulted by algorithm OPT. Moreover, algorithm VFK is of very good scalability which is important for algorithm VFK to be of practical use to generate hierarchical broadcast programs dynamically in a mobile computing environ

关键词： 蓝牙   芯片供应商   闪存产品   博通公司   市场分析   可行性研究   出货量   ZigBee   笔记本电脑   笔记本计算机   高通公司   服务提供商   虚拟个人网络   通信标准   经销商   贸易商   移动计算  

关键词： 笔记本电脑   光盘刻录机   常规武器   享受者   移动计算   数码相机   数码摄像机   无线局域网   IT  

摘要： 和煦的阳光透过落地玻璃窗洒在身上,庭院中柳绿桃红、芳草萋萋,身旁有杯香茗,膝上有台笔记本电脑,这就是你的“办公室”。你甚至会因为挡不住满园春色的诱惑,拿着笔记本电脑跑到楼下的草地上,倚着老槐树,开始你的工作。

关键词： 英特尔   中国   移动计算  

关键词： mobile computing terminals   law enforcement   communication   information   time   deterrence   job satisfaction  

摘要： A major metropolitan police department in the Northeast recently began using mobile-computing terminals (MCTs). This research explores how MCTs have improved critical factors that affect the work environment of the officers in the department, particularly related to deterrence and job satisfaction. A model for investigation is developed and tested using a survey instrument administered to officers using the MCTs. We find that MCTs have enabled better communication among officers and have increased the availability of information, both of which are found to have a significant positive impact on the officers' job satisfaction. Savings in time from plate checks are found to have a significant impact on deterrence. However, though the availability of information from MCTs has a positive impact on deterrence, the relationship is not very significant.

关键词： 河南移动   PHS   爱立信   运营商   移动商务   北电网络   WCDMA   诺基亚   中兴通讯   移动应用开发   移动服务   数据挖掘   移动计算  

摘要： 日前,在瑞士苏黎世举办的“爱立信移动应用竞赛”颁奖典礼上,爱立信宣布了本年度最佳移动应用开发优胜者。LocatioNet、Media Republic、Synergenix Interactive AB及NewBaySoftware榜上有名。 移动应用竞赛是爱立信组织的一个全球性竞赛,旨在发现可以迅速市场化的最佳移动应用,重点是开发能带来价值,创造便利以及使日常生活和工作更加轻松高效的服务。

关键词： 制造业   解决方案   加工工业   英特尔公司   企业信息平台   克莱斯勒   供应链管理系统   移动计算   英特尔架构   助力  

摘要： 您的新产品开发周期是否相对滞后?您的库存成本是否总是居高不下?您的员工是在认真完成本职工作,还是疲于应付各种突发问题?如何以更低的成本实现更高的产出?如何动态地管理库存?如何实现高效的协同?如何快捷地处理海量数据?您是否总是根据过时的信息制订决策?烦琐的书面工作是否使企业的生产力停滞不前?现代制造业正面临越来越严峻的挑战。

关键词： 叉车   上海   叉式装卸车   货车   移动计算   高级项目经理  

摘要： 秦俊峰 中国计算机软件与技术服务总公司副总工程师,中软冠群公司执行副总裁。中国物质与采购联合会常务理事、硕士。 1996年获得加拿大北方电讯认证银卡工程师。系北京市科委和美国SoftTech举办的第一届高级项目经理培训班成员、科技部2001年和2002年、2003年“国家重点新产品”和“国家重点推广新产品”的专家组成员。 参加工作以来,一直从事企业信息化建设方面的研究工作,目前正在从事中国物流园区设施规划建设和物流管理建设以及物流信息化领域等方面的研究工作。

关键词： Mobile computing   Mobile communication systems   Wireless communication systems   Electronic data processing  

摘要： In the approaching era of pervasive computing, we can expect to see a huge population of mobile clients, including people and devices, which require access to information at any place. Hence, the locations of clients and data objects have become important parameters for many information services - what we call location-dependent information services (LDISs). This thesis focuses on the provision of LDISs via wireless broadcasting. Compared to point-to-point connection, wireless broadcast systems provide a more efficient data delivery method that allows simultaneous retrieval of information by numerous clients. However, they introduce many limitations that have not been considered in traditional computing environments. This thesis conducts research on advanced indexing techniques to improve the performance of LDISs；For location-dependent data (LDD). the validity of a data value is dependent on the location of the client retrieving the data value. The retrieval of LDD requires the identification of the region that the client is residing in, given a partition of the geographical space. For example, finding the name of the city that the client is visiting requires identifying which city the client is located in given the city boundaries of a country. D-tree is proposed to efficiently determine the target region by indexing the division of adjacent regions. Compared to the existing approximation methods, such as Minimal Bounding Rectangles (MBRs) in R-tree, D-tree does not index any overlapping region and therefore avoids back-tracking. Compared to decomposition schemes, such as the trapezoidal map, D-tree represents the divisions in the search space and does not introduce any auxiliary line segments to the space. Therefore, the storage cost of D-tree is very low. Simulation results of both synthetical and real datasets show that D-tree outperforms existing indexes significantly in terms of search time；Next, we focus on nearest-neighbor search, which can be answered based

关键词： 中国网通   移动计算   英特尔   中国网络通信有限公司   计算应用  

摘要： 近日,英特尔有限公司与中国网络通信有限公司宣布双方将通过一系列的技术及市场活动扩大在公共热点(hotspot)地区的无线局域网的部署,为商务用户提供完整的无线解决方案,共同推广基于英特尔~((R))迅驰移动计算技术的全新移动计算应用模式。 根据此次的联合推广计划,双方将以英特尔即