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WiMAX具有容量大、可靠性高、传输距离长等特点,在电力系统通信中有一定的应用潜力。文章从物理层、链路层、大覆盖范围、QoS性能等4个方面,对WiMAX的技术展开分析,并结合电力行业的特点,阐述了WiMAX在无线城域网、变电站接入备用通信方式、应急通信、配网自动化等方面的应用,表明了WiMAX可以作为下一代宽带无限接入技术应用于未来的电力系统通信。 相似文献
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In this paper, we propose a global model for WiMAX networks planning. This model represents the network planning problem and helps to solve it entirely without dividing it into several subproblems. The objective of the model is to minimize the cost of the network while maximizing its survivability. The model has been compared to a sequential model with the same constraints, which consists in solving the subproblems sequentially, and to a global model without reliability constraints. The results show that the proposed model performs on an average 25% better than the other models. 相似文献
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ICT Innovation is one of the major forces for socioeconomic development. It is the key element to spur growth of the economy of a nation. Several studies have shown that culture is a crucial determinant of innovations. This study examines the effect of socio-cultural factors on ICT innovation with specific focus on the mobile banking services. Research was conducted on 220 respondents from sampled population in South Africa. The questionnaire used in this study was developed based on previous studies that have proven validity. The findings indicate that culture is an appropriate concept to describe how innovation in information and communication technology can be influenced by human behavior. 相似文献
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2004年世界空调器的发展(上) 总被引:2,自引:0,他引:2
本文综述2004年世界空调器的生产、销售规模和产品的发展趋势. 相似文献
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While artificial vision prostheses are quickly becoming a reality, actual testing time with visual prosthesis carriers is at a premium. Moreover, it is helpful to have a more realistic functional approximation of a blind subject. Instead of a normal subject with a healthy retina looking at a low-resolution (pixelated) image on a computer monitor or head-mounted display, a more realistic approximation is achieved by employing a subject-independent mobile robotic platform that uses a pixelated view as its sole visual input for navigation purposes. We introduce CYCLOPS: an AWD, remote controllable, mobile robotic platform that serves as a testbed for real-time image processing and autonomous navigation systems for the purpose of enhancing the visual experience afforded by visual prosthesis carriers. Complete with wireless Internet connectivity and a fully articulated digital camera with wireless video link, CYCLOPS supports both interactive tele-commanding via joystick, and autonomous self-commanding. Due to its onboard computing capabilities and extended battery life, CYCLOPS can perform complex and numerically intensive calculations, such as image processing and autonomous navigation algorithms, in addition to interfacing to additional sensors. Its Internet connectivity renders CYCLOPS a worldwide accessible testbed for researchers in the field of artificial vision systems. CYCLOPS enables subject-independent evaluation and validation of image processing and autonomous navigation systems with respect to the utility and efficiency of supporting and enhancing visual prostheses, while potentially reducing to a necessary minimum the need for valuable testing time with actual visual prosthesis carriers. 相似文献
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Crude oil, coal and gas, known as fossil fuels, play a crucial role in the global economy. This paper proposes new econometrics modelling to demonstrate the trend of fossil fuels consumption. The main variables affecting consumption trends are: world reserves, the price of fossil fuels, US production and US net imports. All variables have been analysed individually for more than half a century. The research found that while the consumption of fossil fuels worldwide has increased trends in the US production and net imports have been dependent on the type of fossil fuels. Most of the US coal and gas production has been for domestic use, which is why it does not have a strong influence on worldwide fossil fuel prices. Moreover, the reserves of fossil fuels have not shown any diminution during the last couple of decades and predictions that they were about to run out are not substantiated. The nominal and real price of fossil fuels was found to change depending on the type. Finally, estimates of three econometric models for the consumption of fossil fuels from 1949 to 2006 are presented which identify the effects of significant variables. 相似文献
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由于WiFi高的数据传输能力和WiMAX更大的覆盖范围,集成的WiFi/WiMAX网络在将来有很大的发展潜力。针对无线网络中实时业务低时延的需求,提出了一种WiFi/WiMAX混合网络中的快速安全认证模型。该模型基于EAP-TLS协议,将认证过程分为两个阶段:预认证和重认证。通过采用预认证,当MS在WiFi和WiMAX之间切换时,大大减少了认证延时,能在一定程度上支持混合网络中的实时服务。 相似文献