南海、东海蒸发波导出现规律的对比分析

利用2002年1～3月的铁塔平台气象水文数据以及New蒸发波导模型分析研究了南海及东海海域蒸发波导的出现规律,并利用实测数据对模型结果进行了检验.结果表明:南海海域蒸发波导的出现概率、高度、强度分别为100%、13.4m和30.3M,而东海海域分别为90%、9.1m和16.6M;除以14时为代表的中午时刻,南海海域一天当中蒸发波导基本上都出现在不稳定及近中性层结条件下,而东海海域蒸发波导在稳定、不稳定和近中性层结条件下的出现概率差别不大;相对蒸发波导高度而言,New模型诊断蒸发波导出现概率和强度的效果更好;不稳定及近中性弱不稳定层结条件下,New模型诊断的蒸发波导高度偏低,稳定层结条件下模型结果偏高,近中性弱稳定条件下模型结果与实测最吻合.     

The Digital Age of Mobile Cellular Network in Germany and China ：Policies,Technologies and Markets （Part Ⅰ）

The German Postal Reform I in 1989 introduced competition in the mobile cellular market. German cellular operators, DeTeMobil, Mannesmann, E-Plus and VIAG Interkom, built D1-, D2-, E1-and E2-Netze based on GSM standards made in Europe. China Unicom was created in 1994 and China Telecom was separated from MPT in 1995. China Telecom and China Unicom competed in a duopoly from the mid-1990s onwards and the cellular services provided by them also rely on GSM standards. China Telecom additionally deployed XLT technology (PHS) from the late 1990s onwards. While DeTeMobil and Mannesmann conquered approximately 80%-90% of the market throughout the 1990s and were the two dominant market players in Germany, China’s cellular market was mainly controlled by China Mobile. In Germany, prices related to cellular technology continued the downwards trend as a major result of the process of deregulation, liberalisation and competition. In China, price wars had led to significant price reductions in the cellular market. Although network operators in both countries strived to deliver differentiated cellular services, the two national markets in the 1990s were visibly shaped by product homogeneity.     

The Digital Age of Mobile Cellular Network in Germany and China：Policies,Technologies and Markets （Part Ⅱ）

The German Postal Reform I in 1989 introduced competition in the mobile cellular market. German cellular operators, DeTeMobil, Mannesmann, E-Plus and VIAG Interkom, built D1-, D2-, E1-and E2-Netze based on GSM standards made in Europe. China Unicom was created in 1994 and China Telecom was separated from MPT in 1995. China Telecom and China Unicom competed in a duopoly from the mid-1990s onwards and the cellular services provided by them also rely on GSM standards. China Telecom additionally deployed XLT technology (PHS) from the late 1990s onwards. While DeTeMobil and Mannesmann conquered approximately 80%-90% of the market throughout the 1990s and were the two dominant market players in Germany, China's cellular market was mainly controlled by China Mobile. In Germany, prices related to cellular technology continued the downwards trend as a major result of the process of deregulation, liberalisation and competition. In China, price wars had led to significant price reductions in the cellular market. Although network operators in both countries strived to deliver differentiated cellular services, the two national markets in the 1990s were visibly shaped by product homogeneity.     

A memory efficient parallel layered QC-LDPC decoder for CMMB systems

This paper presents a memory efficient architecture of layered decoder for the dual-rate LDPC codes in the China Multimedia Mobile Broadcasting (CMMB) system. An efficient scheme for reducing the memory block number is proposed to increase the memory usage efficiency, so that the quantity of memory bits, decoder area and power consumption is significantly reduced. At the same time, the memory structure keeps the “one cycle one layer access” timing schedule to achieve high decoding throughput. Furthermore, the early termination strategy is employed to further increase the throughput; a non-uniform quantization scheme and an area efficient calculation module are developed to further improve the memory efficiency and hardware resource efficiency, respectively. By using SMIC 130 nm 1P7M CMOS process, the decoder is implemented and the core area is 5.29 mm². The total memory bits consumption is only 130.5 K which consumes 2.53 mm² memory area.     

入世背景下的中国电信业规制改革

长期以来,中国电信市场是一种自然垄断加行政垄断的状态。面对中国即将加入世贸组织的前景,中国电信业的规制改革会经历政企分离,业务分割、创新和开放竞争等几个阶段,初步形成市场竞争的格局。     

中国AS级互联网网络拓扑现状分析

本文介绍了中美两个AS级路由导出观察系统Route Views 和 BGPView.特别对中国互联网网络拓扑现状通过采集大量自治系统(AS)间的BGP(Border Gateway Protocol)路由信息,进行统计分析,提出发展建议.并对改进数据观察和分析系统进行了探讨.     

国内信息无障碍的现状及展望

介绍了信息无障碍的历史沿革、国际信息无障碍的发展过程以及国内信息无障碍的现状,阐述了信息无障碍的社会意义和应用价值,列举了视障人士存在的信息获取障碍和需求范围,对信息无障碍的应用前景进行了展望,并提出信息无障碍对于需求群体、企业和研究机构、政府三者各自的权力、利益和责任。     

电信转型——有计划的革命性变革

本文在研究大量组织变革文献的基础上,指出企业转型就是对企业实施有计划的革命性变革,试图从四个层面建立研究企业转型的框架,并对转型过程进行了初步探讨,最后结合电信企业转型实践,具体分析电信企业如何转型.     

Public interest in continued use of Chinese government portals: A mixed methods study

Public adoption of policies detailed on government websites is an important topic in the field of e-government research, and researchers have mainly focused on the key factors that influence initial adoption. However, there has been much less discussion on factors influencing the continued use of government websites. This study identifies and tests a theoretical model that predicts consumers’ intentions to continue using government portals, using a mixed methods approach based on Grounded Theory. To construct a theoretical framework of public interest in continued use of government information portals, we interviewed 56 respondents and coded the interview data. Next, we tested the resulting model using data collected from a questionnaire-based survey of 354 users. The Structural Equation Modeling (SEM) results indicate that continued use is influenced by psychological perception, user characteristics, service parameters of the government portals and the government’s idea. Of these, psychological perception was found to have the strongest effect. These findings enrich the theoretical system of e-government public adoption of intention and have important practical significance for the development of Chinese government portals.     

2005年中国电信运营市场发展现状与展望

2005年是中国电信业的“转型年”．国内电信运营商依赖投资拉动增长速度减缓的趋势得以深化。国内电信运营商的投资更加趋于理性。通过总结2005年田内电信运营市场态势、各运管商发展策略、行业热点及未来展望四个方面阐述国内电信运营市场的发展状况。