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101.
The Research of ST-OFDM in Physical Layer of IEEE 802.16a 总被引:1,自引:0,他引:1
JU Mei-yan ZHU Qi FENG Guang-zeng Department of Communication Engineering Nanjing University of Posts Telecommunications Nanjing P.R.China 《中国邮电高校学报(英文版)》2004,11(4)
This paper briefly introduces one of the three physical layer implementations of IEEE 802.16a~[1],WirelessMAN-OFDM PHY.Based on the implementation,the combination of Orthogonal Frequency Division Multiplexing(OFDM)and Space-Time Coding(STC)which is briefly called ST-OFDM in IEEE 802.16a,is investigated under thechannel provided in Ref.[2].Especially,this paper is focused on the influence of the optimal decision threshold on the sys-tern Bit-Error-Rate(BER)performance based on unequal probabilities of sources.The simulations show that when Signal-Noise-Ratio(SNR)is low the optimal decision threshold is obviously superior to the usual one;when SNR is high to someextent,such as 10 dB for 4QAM and 16 dB for 16QAM,we can use the usual decision threshold instead of the optimal 相似文献
102.
����ѡ������Ļ�ɫ���߷��� 总被引:2,自引:0,他引:2
本文根据灰色系统理论中的灰色决策原理,提出了一种合理选择钻机的新方法,并通过了实例验证。结果表明,这种方法切实可行。 相似文献
103.
线性规划模型的自动生成与求解 总被引:1,自引:0,他引:1
本文描述了《有色企业经济活动分析决策支持系统》模型库中线性规划模型的自动生成与求解系统的设计思想、方法及实现 相似文献
104.
Greater use of psychological research and practice knowledge in the formulation of social policy is necessary to enhance the well-being of U.S. citizens and communities. Although historically there are instances in which psychological and social science research and practice have had a substantial influence on federal policy, for the most part the relationships among research, practice, and policy have been tenuous. Three cases in which research has substantively influenced policy over the past 80 years are reviewed: Keynesian economics, Head Start legislation, and the activities of conservative think tanks. Several recommendations are made for ways in which psychologists can enhance their influence in the policy arena, including communicating directly with policymakers regarding relevant policy findings and knowledge gleaned from practice; conducting interdisciplinary, multilevel research as well as evaluation research (including qualitative data drawn from practice settings); and networking among researchers, practitioners, policy advocates, and social action groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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The authors propose a behavioral decision theory relevant to the maintenance of desirable identities. The theory, termed deviance regulation theory (DRT), predicts that actions translate into meaningful identities to the extent that they cause the individual to deviate from reference group norms. This straightforward proposition is used to predict the patterning of behavior across a wide array of social contexts. The authors present evidence that predictions generalize across Eastern and Western cultures and to both personal and collective identities. Finally, they show how DRT alters current theoretical assumptions about social motives and social and cultural influence, and they illustrate how it can help explain the structure of both informal and formal social forces. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
108.
唐红兵 《水电自动化与大坝监测》2006,30(1):69-71
决策支持系统是水库优化调度实用化的发展方向,对于提高水电站生产效益和水库调度管理水平具有重要意义。结合国电公司重点科技项目“天生桥梯级水电站联合调度决策支持系统”的开发,阐述了开发水电调度决策支持系统实现水库调度实用化的经验:正确反映用户需求、增强用户对系统的控制、用模拟仿真弥补优化调度的不足、用数据库技术扩展水库优化调度实用化功能。 相似文献
109.
This article reviews research on the implementation of media-rating systems, parents' use and evaluation of them, and the impact of ratings on children. Although half or more of parents report using media-rating systems, understanding of various components of the systems is low, particularly for television ratings. A meta-analysis of national polls shows that parents overwhelmingly prefer that ratings specify content, rather than giving age recommendations. A second meta-analysis, of experiments testing the effects of ratings on children's interest in programs, shows that ratings indicating restricted or controversial content have a deterrent effect for children under age 8 but that, by age 11 and especially for boys, the ratings show a small enticement effect. This effect occurs for both age-based and content-based ratings. Implications for policymakers and parents are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
110.
Pareto multi-criteria decision making 总被引:1,自引:0,他引:1
The paper concerns design governed by multiple objective criteria, which are conflicting in the sense of competing for common resources to achieve variously different performance objectives (financial, functional, environmental, esthetical, etc.). A multi-criteria decision making (MCDM) strategy is proposed that employs a tradeoff-analysis technique to identify compromise designs for which the competing criteria are mutually satisfied in a Pareto-optimal sense. The MCDM strategy is initially developed for the case of design governed by n = 2 objective criteria. It is then extended to design governed by n > 2 objective criteria, by introducing the concept of primary and aggregate criteria. It is proved that, from among the theoretically infinite number of feasible designs forming the Pareto front for a design problem governed by n independent objective criteria, there exists a unique Pareto-compromise design that represents a mutually agreeable tradeoff between all n criteria. This remarkable result is illustrated for a flexural plate design governed by n = 2 criteria, a bridge maintenance-intervention protocol design governed by n = 3 criteria, and a media centre envelop design governed by n = 11 criteria. 相似文献