北斗卫星导航系统在应急预警信息发布中的应用

应急预警信息发布在自然灾害应急管理中具有极其重要的地位和作用,现有应急预警信息发布技术从高效性、精准性、安全性等方面均难以满足不断提升的自然灾害应对需求。北斗卫星导航系统具备短报文通信、国际搜救、精密定位等能力,将北斗卫星导航系统应用于自然灾害的应急预警信息发布中,能够在应急预警信息的关键点监控、风险研判、信息传播等方面发挥至关重要的作用,对于提升应急预警信息发布的效率意义重大。     

危机传播中我国应急广播的角色定位研究

德国社会学家乌尔里希·贝克认为，“风险社会”已经到来，各类危机事件随时可能发生。作为主流媒体，应急广播具有鲜明的权威性和公信力，这决定了其要在危机事件来临时承担更多的社会责任。同时，应急广播还具有信息发布快、伴随性收听、受众易接收、具有亲和力等诸多特性，这决定了应急广播在危机传播中扮演着重要角色。本文对应急广播在危机事件中应有的角色定位进行探析，以期能够帮助应急广播的管理者和运营者对其担负的职责与使命认识得更加清晰、准确，让应急广播的角色和功能得以完整体现，为公众提供更加全面、高效的应急信息公共服务。     

科学传播和技术传播

科学传播研究和技术传播研究在国内已经成长为颇有吸引力的研究领域,但一些基本概念的不甚清晰,人们的理解也不甚一致。科学传播与技术传播的区别并不在于传播的内容是科学还是技术,而是在于传播的目标与任务、技术的角色、流动的关键信息、面对的对象群体、利用的渠道手段等一些方面。     

网络多对多传播模式下的企业营销传播困境

相比于传统媒体,网络媒体的信息传播模式由“一对多”转变为“多对多”模式。在网络多对多传播模式下,企业面临着负面信息无法控制、正面信息无法凸显等营销传播困境。解决企业营销传播困境的办法是以正面信息来覆盖负面信息,企业可以通过信息内容、信息发送者、信息传播渠道、亚网络和舆论领袖等方面的整合,打造一条凸显正面营销信息的路径。     

坚持创新做好应急广播工作——以阳谷县应急广播为例

应急广播系统是应急信息快速传播渠道和传播平台，当发生重大突发事件、自然灾害等公共危机时，能在短时间内起到有效保护人民群众的生命和财产安全的作用。因此，应急广播维护、应急广播信息接收和系统终端设备供电尤为重要，基于此，着重介绍阳谷县应急广播系统运维工作，DTMB机顶盒接收应急广播信号技术，终端设备增加太阳能供电两项技术的实际应用和取得的成效。     

手机媒介的传播特点和传播控制

手机是一种以个性化的工具;手机报纸、手机电视等功能整合了文字阅读、声音传输和影像等特点,以多媒体方式呈现;开始承载起传播信息和文化的新功能。随着信息发送者变成了信息接收者、信息生产者变成信息了消费者,社会信息流程变得更加复杂。本文研究关于手机在数字通讯行业与现代传媒融合的传播特点,及其信息过滤和控制。     

应急广播在内蒙古气象灾害预警发布中的应用分析研究

本文分析了内蒙古地区试点布设旗县的主要气象灾害种类及其影响特点，主要气象灾害可能造成危害程度、紧急程度和发展势态，以及相关气象灾害风险预警的发布标准。采用统计分析和图表对比等方法，对预警信息发布的有效性进行了检验和评估，结果显示预警信息发布与气象灾害发生的时空分布基本吻合。文章通过对预警信息发布和传播的时效性研究，探索较为客观的定量分析评估方法，直观反映现有的发布渠道送达率，为发布策略的完善和改进提供科学参考。     

手机媒体的传播特点和传播控制

手机是一种个性化的工具,以手机报纸、手机电视等功能整合了文字阅读、声音传输和影像等,以多媒体方式呈现,开始承载起传播信息和文化的新功能.随着信息发送者变成了信息接收者、信息生产者变成了信息消费者,社会信息流程变得更加复杂.本文研究关于手机在数字通信行业与现代传媒融合中的传播特点,及其信息过滤和控制.     

气象信息的新媒体传播

在数字技术的推动下,新的媒介时代带来了传统电视媒体传播空间、传播内容、受传关系的改变,人们接收信息的渠道越来越趋于多元化.气象信息的新媒体传播旨在以服务为导向的前提下,在开路电视传播的基础上,利用各种新兴媒体资源,实现对各级政府、目标消费者更加及时、精准、到位的气象服务.在信息时代,借助开路电视频道、数字有限付费频道、网络电视和手机电视平台等,气象产品的社会价值被极大地激发出来,将极大地促进我国气象服务整体质量的跃升.     

应急广播传播模式

应急广播的传播模式与其他广播的传播模式不同,应急广播的建设与使用关系着人民的生命财产安全.因此,应急广播在议程设置主要是以人为本.应急广播的系统具有架设简捷传播距离远以及传播速度快等特点,这样的传播系统能够在突发事件中起到应急疏散、预告以及指挥等作用.笔者对应急广播主要技术进行了分析,并探讨了应急广播的传播模式.     

Information dissemination and automatic information systems

Automatic information dissemination, search, and retrieval systems have become increasingly important in recent years, because of the urgency of the information problems themselves, and also because of a wide-spread feeling that computers can help in providing the much needed solutions. Over the past few years much has been learned about the design of automatic information systems and about the effectiveness of various types of analysis and search procedures. The present report reviews the principal techniques of interest and provides a forecast of the systems design and type of operations likely to be implemented in automatic information systems of the future. The information dissemination process is first examined in detail. The main functions and organization of information systems are then reviewed, and present capabilities are described using some of the currently existing operational systems as examples. Finally, future systems are considered, including in particular those based on automatic content analysis and on user-controlled searches. Specifically examined are author indexing and automatic analysis techniques, automatic typesetting and composition procedures, automatic and semiautomatic dictionary construction, and iterative search techniques.     

Fair content dissemination in participatory DTNs

Thanks to advances in the computing capabilities and added functionalities of modern mobile devices, creating and consuming digital media on the move has never been so easy and popular. Most of the DTN routing protocols proposed in the literature to enable content sharing have been exploiting users’ mobility patterns, in order to maximise the delivery probability, while minimising the overall network overhead (e.g., number of message replicas in the system, messages’ path length). Common to all these protocols has been the assumption that devices are willing to participate in the content distribution network; however, because of battery constraints, participation cannot be taken for granted, especially if the very same subset of devices are continuously selected as content carriers, simply because of their mobility properties. Indeed, we demonstrate that state-of-the-art DTN routing protocols distribute load in a highly unfair manner, with detrimental effects on delivery once the assumption of unconditional participation is lifted. To overcome this limitation, we propose a load-balancing mechanism whereby nodes maintain local estimates of network workload, and use them to direct traffic towards the least loaded portion of the network. We implement the mechanism on top of a source-based DTN routing protocol, and demonstrate, by means of simulation using a variety of real mobility traces, that high delivery is now achieved without compromising fairness.     

Proactive data dissemination to mission sites

In many situations and domains it is important to deliver information to personnel as they work in the field. We consider a specialized content distribution application in wireless mesh networks. When a new mission arrives??for example, when a fire alarm sounds??data is pushed to storage nodes at the mission site where it may be retrieved locally by responding personnel (e.g., police, firefighters, paramedics, government officials, and the media). It is important that information is available at low latency, when requested or pulled by the personnel. The total latency experienced will be a combination of the push delay (if the personnel arrive at the mission site before all the data can be pushed), and the pull delay. Each delay component will in turn be a function of (1) the hop distance traveled by the data when pushed or pulled and (2) any congestion on the links. In this paper, we define algorithms and protocols that trade-off the push and pull latencies depending on the type of application. Our goal is to choose a storage node assignment minimizing the total latency-based cost. We start with a simple model in which cost is a function of distance, and then extend the model, explicitly taking congestion into account. Since the problem is NP-hard even to approximate, our focus is on developing efficient algorithms and distributed protocols that can be easily deployed in wireless mesh networks. In NS2 simulations, we find that our heuristic algorithms achieve, on average, a cost within at most 15% of the optimum.     

Thinking of modern wushu dissemination method

martial arts in China for thousands of years culture heritage plays an important role, today has become a symbol of Chinese national culture. Martial arts in the long history of several thousand years, continuous development and fusion, formed a unique mode of transmission, and under the changing trend of the development of modern science and technology, not according to the traditional Chinese wushu dissemination, combined with the contemporary science and technology, network promotion, development of martial arts school, strengthen the cultural background, is the best way out for the spread of Chinese martial arts.     

Characterization and concepts of time-frequency dissemination

Fundamental considerations that arise in designing a time or frequency dissemination system, are discussed and some dissemination methods are surveyed. A section on "Signal design for time and frequency dissemination" briefly summarizes radio propagation characteristics, discusses time signal format design, and considers how noise affects time and frequency signals. We point out fundamental techniques of time and frequency dissemination and describe similarities between systems for time dissemination and navigation. The use of synchronous satellite transponders and commercial television systems for time dissemination is emphasized because of their great promise. No attempt is made to cover every existing dissemination system; some systems are treated elsewhere in this Special Issue on Time Frequency. The concluding section gives three categories of users according to their required accuracy and shows typical systems which can provide desired accuracies. Various dissemination techniques are charted and evaluated in terms of salient characteristics such as accuracy, geographical coverage, cost factors, and others. To alleviate an existing frequency spectrum problem, we suggest that designers of communication and navigation systems consider opportunities for including time and frequency dissemination in their systems.     

On efficient 3D data dissemination

Data broadcast is an advanced technique to realize large scalability and bandwidth utilization in a mobile computing environment. Three dimensional (3D) contents are emerging data in the data broadcast. However, traditional data broadcast did not consider 3D data to design a data schedule in a broadcast channel. Therefore, the abovedrawback leads to large access delay in the 3D data broadcast. In this paper, we remedy the problem by devising an indexing technique to index the 3D data of variant geometry shapes. We propose an indexing technique using a 3D data index tree to minimize average waiting time and average tuning time for broadcasting the 3D data. Experimental results show that our approach is able to generate broadcast programs including the 3D data indices with high quality and is very efficient in the 3D data broadcast.     

Data dissemination over wireless sensor networks

In sensor networks, it is crucial to design and employ energy-efficient communication protocols since nodes are battery-powered, and thus their lifetimes are limited. We propose a data dissemination protocol for periodic data updates in wireless sensor networks, called SAFE (sinks accessing data from environments), which attempts to save energy through data delivery path sharing among multiple sinks that have common interests. Simulation results show that the proposed protocol is energy-efficient as well as scalable to a large sink population.     

Efficient and reliable link state information dissemination

Distributing link state information may place a heavy burden on the network resource. In this letter, based on the tree-based reliable topology (TRT), we propose a simple but efficient and reliable scheme for disseminating link state information. We show that the computational complexity of computing the subnet topology over which link state information is distributed is the same as that of computing the minimum spanning tree.     

Performance analysis of information dissemination by flooding

Performance properties are established for the dissemination by flooding of a database that is initially distributed among the nodes of a communications network. An example of this general process is the dissemination of network status information as a component of the adaptive routing mechanism in a network like Arpanet. Bounds are given on the progress of the dissemination process at a sequence of times before the completion of the process, whereas earlier results only bounded the time until completion. The present bounds further extended earlier analysis by treating the diameter explicitly as a parameter. Specialized versions of the bounds are given for k-connected networks. The bounds yield a recognition property whereby a node can recognize that it has received the entire database without having a priori knowledge of the size of the database. An earlier assumption about a fixed time for correct message transmission over any edge is relaxed to assume only an upper bound on these transmission times