日本都道府县防灾无线网的建设及借鉴

日本是世界上灾害管理通信系统建设领先的国家,相关经验对我国灾害管理通信系统的建设有着重要的借鉴意义。都道府县防灾无线网是日本灾害管理通信系统的重要组成部分,已具备了较为成熟的建设模式和应用经验。本文介绍了日本灾害管理通信系统的框架、都道府县防灾无线网的体系架构及其通信系统组成,选择了神奈川县、长野县和三重县作为典型案例,对这三个县的防灾无线网的建设和应用情况作了分析,并借鉴日本的经验,结合我国的实际,提出了五个方面的建设建议。     

A strategy for third-party logistics systems: A case analysis using the blue ocean strategy

One of today's most frequently discussed topics in the business world is how to escape from the intense Red Ocean and how to create an uncontested Blue Ocean. However, because there are few practical guidelines available on this topic, we will introduce a case study of a third-party logistics (3PL) provider, CJ-Global Logistics Service (CJ-GLS), to show how it aspires to be a leader in the newly introduced 3PL industry in South Korea. CJ-GLS is a latecomer in the logistics industry, and its resources, such as the number of trucks and warehouses, are relatively small in comparison to those of established companies. But, it has achieved a distinct competitive advantage through innovative information technology (i.e., RFID—radio frequency identification), which has enabled it to create an uncontested market space, electronic logistics business. One remarkable fact about CJ-GLS is that its swift growth comes not from attracting competitors’ customers from the existing Red Ocean market but from creating a Blue Ocean market (3PL market), which previously existing incumbents ignored, and also from constructing a new business model founded on a RFID-based, ubiquitous-oriented 3PL system. Analyzed through a Four Actions Framework and characterized as Blue Ocean, this case study provides valuable information on how a company reinforces its competitive advantage from the Red Ocean while it transitions into a Blue Ocean by utilizing advanced information communication technologies.     

Throughput and delay analysis of an opportunistic tree algorithm

Tree algorithms are a well-known class of random access algorithms with a provable maximum stable throughput under the infinite population model (as opposed to ALOHA or the binary exponential backoff algorithm). In this article, we propose a tree algorithm for opportunistic spectrum usage in cognitive radio networks. A channel in such a network is shared among so-called primary and secondary users, where the secondary users are allowed to use the channel only if there is no primary user activity. The tree algorithm designed in this article can be used by the secondary users to share the channel capacity left by the primary users.

We analyze the maximum stable throughput and mean packet delay of the secondary users by developing a tree structured Quasi-Birth Death Markov chain under the assumption that the primary user activity can be modeled by means of a finite state Markov chain and that packets lengths follow a discrete phase-type distribution.

Numerical experiments provide insight on the effect of various system parameters and indicate that the proposed algorithm is able to make good use of the bandwidth left by the primary users.     

论1928-1929年国民政府建委会的无线电管理

论述了建委会管理期间无线电取得的成绩;并从合法性、人事和有线电争权三方面对交通部与建委会的无线电管理权的争论进行了分析;无线电管理权重归交通部.近代电信业历经的种种问题,对今天电信业的发展不失借鉴作用.     

非公有资本介入广播电视行业的规制及路径

随着我国广播电视国有经营性文化单位转企改制的不断深入,非公有资本将进一步渗透到该领域,成为推动我国广播电视产业发展的重要力量。依据现行相关规定,非公有资本可以介入到广播电视业的影视内容制作与发行、频道频率运营、数字电视运营以及新媒体产业运营等领域。现阶段,非公有资本进入广播电视行业还存在一定的障碍。政府应出台相应的扶持保障政策,社会制作机构应建立行业协会,同时拓宽播出渠道、创新盈利模式．共同推进广播电视产业的社会化分工、专业化生产。     

Narratives from the neighbourhood: The discursive construction of integration problems in talkback radio1

This paper examines how speakers deploy narrative devices in talking about Sudanese refugees. Particularly, we show how narrative constructions form an important basis for the advancement of accounts about integration problems into the local polity. We analyse talkback ‘phone‐in’ calls to a local Adelaide radio station that provide callers an opportunity to give accounts of events and social phenomena that concern them in their local settings. Analysis shows that speakers regularly deployed narrative constructions, first‐hand ‘witnessing’ devices that functioned to legitimate accounts as veridical versions of events, and contrast devices to explicate the moral and behavioural aberrance of Sudanese refugees. The analysis illustrates how these discursive devices function rhetorically in interaction, in ways that differentiate Sudanese refugees as problematic. Through this analysis, we contend that narrative devices precipitate and bolster socio‐political policies that have serious, negative consequences for Sudanese refugees.     

宽带数字下变频的高效实现方法研究

针对软件无线电接收机中数字下变频的特点,提出了一种合理的基于FPGA实现宽带数字下变频的方案,即分级实现以降低抗混叠滤波器的阶数;并且每级采用不同算法实现滤波抽取以占用不同资源,从而实现FPGA总体资源的合理、高效利用。另外,论述了一种适合FIR抽取滤波器的算法——时钟选择运算法,并通过Altera公司的EP2S60F484C4对该算法进行了测试,验证了它的高效性。     

抗战时期的清华无线电研究所

清华无线电研究所是抗日战争时期清华大学创办的两个物理类研究所之一,也是中国大学中建立的第一个无线电专业研究机构。根据有关档案和文献资料,对该所的筹建、迁移、科研工作情况等进行了考察,初步总结了其在科学研究、人才培养等方面取得的成绩。该所几经搬迁,聚散不定,为了满足抗战的需要,在相当困难的条件下进行了一系列科学研究工作,研制出多种无线电技术设备,同时在国内外杂志上发表了一批研究论文,也培养了一批专业人才。清华无线电研究所的工作不仅为抗日战争作出了重要贡献,而且对中国无线电技术和电子学的发展产生了积极的推动作用。     

“村村通”广电建设中存在的问题与对策研究

国家对基层广电事业提出了确保"村村通"长期通的新目标,但由于西部基层广电事业自身固有的问题以及在"村村通"建设中产生的新矛盾,完成艰巨任务存在很大困难.而且西部基层广电事业原有的资源条件和经营环境受挤严重,旧的发展方式力不从心,困局渐显.政府主导、行业直管、整合资源、纵深开发是西部基层广电事业改革发展,建立"村村通"长效机制的关键性策略.     

无线电台站呼号系统管理现状及改革趋势

无线电技术的广泛应用,催生了一系列无线电台站呼号系统管理新问题。首先阐述了无线电台站呼号系统的基本情况;然后梳理了典型国家和地区的无线电台站呼号系统管理现状,深入论证了我国无线电台站呼号系统管理改革的必要性。在此基础上,提出一种新的无线电台站呼号系统管理模式,从管理链条、法律法规、管理平台和监督体制四方面加强建设,有效提高我国无线电台站呼号系统管理工作水平。