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101.
何毅 《电子科技大学学报(社会科学版)》1998,(5)
针对卫星间光通信链路需求,分析了卫星间激光通信系统关键技术分布。介绍具有自动跟瞄功能的激光通信系统光学天线构成方式,对主要性能参数进行了设计和计算。 相似文献
102.
对半导体激光器进行光学准直是空间光通信系统必须进行的重要工作。文中简述了准直通常使用的方法,测试了使用单透镜对一种35mW半导体激光器的准直结果,准直效率约为60%,准直后的发射角为04~075mrad。 相似文献
103.
战术移动通信网的网络拓扑结构随战场环境的变化而变化,为此网络拓扑结构具有重组的能力,网络拓扑重组后必须进行链路频道的重新分配,文中提出的频道分配技术是在避免同频道干扰条件下任一频道可在全网内多次重复使用,以提高频道的重复利用率,同时分析了该情况下网络至少应拥有的频道数,以保证网络有足够的频道供分配。 相似文献
104.
Worldviews or Social Groups as the Source of Moral Value Attitudes: Implications for the Culture Wars Thesis 总被引:1,自引:0,他引:1
Individual moral value attitudes are typically explained by reference to social experiences as indicated by social group variables. Contrary to this view, the emergent culture wars perspective claims that two worldviews that transcend social groups are ultimately and fundamentally responsible for moral value attitudes. Although this relationship has been claimed for the general population, it has not been investigated with national representative data. This paper contrasts the worldview and social group explanations by examining the relative importance of the worldviews implicated in the culture wars literature and the social groups found to be important in previous research. I find social groups to be more important than worldviews, but that worldviews also have explanatory power. I conclude with a discussion about possible clarifications of the culture wars thesis. 相似文献
105.
Quantitative Estimates of Risk for Noncancer Endpoints 总被引:2,自引:0,他引:2
While quantitative estimates of risk have been a standard practice in cancer risk assessment for many years, no similar practice is evident in noncancer risk assessment. We use two recent examples involving methylmercury and arsenic to illustrate the negative impact of this discrepancy on risk communication and cost-benefit analysis. We argue for a more balanced treatment of cancer and noncancer risks and suggest an approach for reaching this goal. 相似文献
106.
In the history of warfare, there are a number of examples of strategic uses of asymmetric technologies. Consistent with history and theory, individuals, organizations and nations have spotted opportunities to employ information and communications technologies to gain and exploit asymmetric advantages and to counter asymmetric weaknesses. This article discusses various asymmetries associated with institutions, nations and organizations that influence the ICT-national security nexus. Regulative, normative and cognitive institutions in a country provide various mechanisms that affect the nature of positive and negative asymmetries. Nations and organizations also differ in terms of their capability to assimilate ICT tools to gain positive asymmetries and deal with vulnerabilities of negative asymmetries. Integrative approaches that combine policy and technological measures at various levels are likely to make the world more secure. 相似文献
107.
Katherine A. McComas 《Risk analysis》2003,23(6):1257-1270
This article offers longitudinal data tracking people who did and did not attend a series of public meetings in an upstate New York rural community grappling with the expansion of an existing solid waste landfill and remediation of an adjacent inactive hazardous waste site. Before and after the public meetings, mailed questionnaires measured risk perceptions and perceived credibility of risk managers (here, the state government agencies and the responsible industry) conducting the meetings. Respondents at each measurement point included meeting attendees and nonattendees, with some fluctuation over time when attendees at one measurement point were nonattendees at the next and vice versa. The results from the first survey indicate that following the first two public meetings, attendees perceived greater risks from the waste sites than did nonattendees; attendees also perceived the risk managers as less credible. After the third public meeting, the results showed that attendees' risk perceptions remained steady; however, perceptions of government agency credibility significantly decreased. After the fourth public meeting, the survey found that attendees' risk perceptions were again not significantly different, whereas perceptions of government agency credibility increased significantly. The industry's credibility also increased, though only among attendees who had attended the most recent public meeting, not among attendees who had attended both the third and fourth public meetings. For nonattendees, risk perceptions and credibility ratings did not change. The discussion examines how distinctive characteristics of communication at each public meeting may have resulted in different effects and proposes hypotheses for future research. 相似文献
108.
论晚明文人评点本的价值和传播机制 总被引:1,自引:0,他引:1
聂付生 《复旦学报(社会科学版)》2003,(5):135-140
晚明是文学评点的鼎盛期和丰收期 ,不但汇评、集评的形式大量出现 ,而且形成了评点名篇为中心、各层次的作品均有评批的评点格局 ;这些文学评点具有很强的文本价值 ,一些重要的文艺理论都是在评点中形成、发展、流行起来的 ;同时它有一套调节接收者期待视界的传播机制 ,在提升传播速度、导引读者等方面起着重要的作用。 相似文献
109.
The Determinants of Trust and Credibility in Environmental Risk Communication: An Empirical Study 总被引:8,自引:1,他引:8
This study examines a key component of environmental risk communication; trust and credibility. The study was conducted in two parts. In the first part, six hypotheses regarding the perceptions and determinants of trust and credibility were tested against survey data. The hypotheses were supported by the data. The most important hypothesis was that perceptions of trust and credibility are dependent on three factors: perceptions of knowledge and expertise; perceptions of openness and honesty; and perceptions of concern and care. In the second part, models were constructed with perceptions of trust and credibility as the dependent variable. The goal was to examine the data for findings with direct policy implications. One such finding was that defying a negative stereotype is key to improving perceptions of trust and credibility. 相似文献
110.
基于模糊判断矩阵信息确定专家权重的方法 总被引:4,自引:3,他引:4
本文对群组模糊判断矩阵集结过程中确定专家权重的问题进行了研究,建立了模糊判断矩阵的特征矩阵和求解群集结矩阵的最优化模型,通过矩阵之间距离度量判断信息自身逻辑一致性程度和群体相容性程度,给出一种基于专家判断信息的可信度计算其后验权重的方法,最后用算例予以说明. 相似文献