基于Tetra网的集装箱物流无线通信平台——实现物流系统“海陆对接、天地一体”     

韩刚  陈国华  陆建洛  林奕炯 《上海海事大学学报》2006,(Z1)

阐述上海港现有的无线通信问题,对建立上海国际航运中心集装箱物流系统的无线通信问题进行深入研究,提出基于Tetra技术的“海陆对接、天地一体”的无线通信平台构架,并在洋山港和外五港区得到应用．实践证明所提出的无线通信平台构架可行有效．  相似文献   

基于GAN序列的卫星数据接收系统故障定位     

王正晟  李亚林  张洪群 《中国科学院大学学报》2023,40(1):109-118

现有的卫星数据接收系统故障定位方法受困于专家知识的难以获取。提出一种基于生成对抗网络(GAN)序列的故障定位方法GANseq。利用故障传播特性,将接收系统分解为M个信号处理单元(SPU),形成一个按照信号处理顺序排列的SPU序列;将故障定位问题转化为有序排列的M个异常检测子问题,其中第m个子问题为对前m个SPU的联合状态的异常检测;然后针对每个子问题采用基于GAN的状态参数检测模型,进而形成GAN序列;综合分析该序列在所有子问题上的检测结果以定位故障SPU。利用实际接收系统进行的实验证明所提出的GANseq不仅从数据驱动的角度完成了故障定位,而且在总体上降低了虚警率,并提高了定位精度。  相似文献   

基于深度强化学习方法的无线多跳网络能量高效机会路由     

靳晓晗  岩延  张宝贤 《中国科学院大学学报》2022,39(3):410-420

由于机会路由能够利用无线信道的广播特性和有损特性,因此一直是提高无线网络路由性能的一个很有效的途径。提出一种基于深度强化学习的无线多跳网络能量高效机会路由算法,该算法使得智能体能够通过训练学习最优的路由策略,以通过机会路由的方式减少传输时间,同时平衡能耗延长网络寿命。此外,本算法还可以极大地缓解冷启动问题并获得较好的初始性能。仿真结果表明,与现有算法相比,该算法具有更好的性能。  相似文献   

效率和公平:网络信息资源建设和配置中信息政策法规的价值   总被引：3，自引：0，他引：3  

王株梅  马海群 《图书与情报》2006,(5):43-47,55

文章分析了我国网络信息资源建设现状及存在的问题，对信息政策法规的公平价值和效率价值进行了探讨，并论述了在网络信息资源建设过程中信息政策法规的公平和效率价值的具体体现。  相似文献   

Analysis of the urban/rural broadband divide in Canada: Using GIS in planning terrestrial wireless deployment   总被引：3，自引：0，他引：3  

M. Sawada  Daniel Cossette  Barry Wellar  Tolga Kurt 《Government Information Quarterly》2006,23(3-4):454

Millions of Canadians residing in Canada's northern, isolated, rural, and remote communities do not have broadband Internet access. This situation has led to a national “broadband divide.” That is, the deployment of wireline broadband is very limited in Canada's northern, isolated, rural, and remote areas because of the significant expense of installation and maintenance of the wired infrastructure needed to reach dwellings in these locations.Terrestrial broadband wireless technology, on the other hand, does not entail the same kind of physical infrastructure. As a result, there are dramatic changes in how spatial considerations affect the provision of broadband Internet services (BIS) to areas beyond the urban zone. In particular, the spatial question is now focused on assessing the capacity for different technological solutions to reach profitable population bases, and brings to the forefront organizations that are developing non-line-of-sight (NLOS) technologies that would permit wireless Internet access over much greater distances than current solutions.We begin this paper by establishing the importance of broadband connectivity to Canada's northern, isolated, rural, and remote communities. This discussion comments on the role of the Government of Canada in the provision of broadband connectivity to residents of these communities, and outlines the current regulatory issues that govern wireless services and policy formulation.The second part of the paper illustrates the use of geographic information system (GIS) approaches in the study of wireless broadband planning and deployment. Case study findings suggest that GIS applications can make a significant contribution to the analysis of wireless deployment planning, to the understanding of the relationships between wireless signal sources and consumers, and to the spatial configuration of terrestrial wireless broadband networks. We conclude the paper by discussing how the GIS approach employed could be used to inform the public policy process with regard to increasing access to broadband Internet services in all regions of the country, and thereby providing the opportunity for all Canadians, regardless of location, to fully participate in the Information Society.  相似文献   

通信工程实验室的构建   总被引：3，自引：0，他引：3  

付洪威  杨华  刘云 《实验技术与管理》2006,23(11):140-142

通过通信工程实验室的构建,提出了以实验箱为主体,计算机网络设备为载体,同时构建以数字程控交换机和网络交换机为核心的程控交换系统方案,该方案不仅可以实现固定电话信号的传输,而且能够支持无线通信,更好地满足通信专业的本科教学和学科建设。  相似文献   

方位词"上下"的汉英对比分析     

才雅南 《牡丹江教育学院学报》2005,(1):13-14

语言中方位的表达方式体现了人们对空间关系的基本认识.对某一具体的空间关系,汉英语中的表达形式可能互有异同,这体现了两种语言的使用者在认识上的差异.本文对方位词"上下"在汉英语中表达法的某些典型异同及其原因进行比较分析.  相似文献   

高校定位与高等教育系统秩序的形成     

何超 《高等教育研究》2007,(2)

高校定位是高校对自身发展方向和发展路径的理性选择,高等教育系统秩序的形成是建立在高校定位基础之上的组织化过程。高校分类只是对高等教育系统秩序认识的特例,仅仅用高校分类与自生秩序相结合来建构高校定位机制是不够的。高等教育系统秩序的形成是一个组织化过程,既有人类理性的安排,又有自组织方式。因而,高校定位应该由政府宏观引导、社会广泛参与、高校理性选择三者共同发挥作用。  相似文献   

Mathematical Analysis of Energy Efficiency in IEEE 802.11 DCF     

高波杨宇航  马惠业 《天津大学学报(英文版)》2005,11(5):332-337

The standardized IEEE ,802. II distributed coordination function （ DCF） provides a contention-based distributed channel access mechanism for mobile stations to share the wireless medium. However, when stations are mobile or portable units, power consumption becomes a primary issue since terminals are usually battery driven. This paper proposes an analytical model that calculates the energy efficiency of both the basic and the RTS/CTS access mechanisms of the IEEE 802. II protocol. The model is validated with simulation results using NS-2 simulation package. The effects of the network size, the average packet length, the initial contention window and maximum backoff stages on the energy efficiency of both access mechanisms are also investigated. Results show that the basic scheme has low energy efficiency at large packet length and large network size, and depends strongly on the number of stations and the backoff procedure parameters. Conversely, the RTS/CTS mechanism provides higher energy efficiency when the network size is large, and is more robust to variations in the backoff procedure parameters.  相似文献   

论古代文学研究的"当下关怀"     

欧明俊 《江西师范大学学报(哲学社会科学版)》2007,40(2):33-39

呼吁古代文学研究的“当下关怀”,并提出一些思考和建议。古代文学研究应在坚守审美本位、纯文学本位、纯学术本位的前提下,尽可能地关注现实,关注国计民生、世道人心,主动介入、积极参与政治文明建设、道德建设和社会文化建设,对当下流行的文学思潮、文化思潮做出“回应”,发出自己的声音。古代文学研究只有走出象牙塔,贴近现实生活,贴近公众,才更有活力。古代文学只有走进当下,才会“复活”起来,才更有价值。古代文学研究者应“定位”为人文知识分子,以学术研究为高尚事业,代表社会良心和公论,将自己的思想识见贡献给时代,实现人生理想。  相似文献