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991.
首先介绍了TH—PPM UWB信号,然后从理论上对加性高斯白噪声(AWGN)信道下系统的性能进行了分析,包括误码率分析和系统容量分析,最后对系统的误码率和接入用户数进行了仿真比较。结果表明,重复码长度、脉冲重复时间和用户数目的选取对系统的误码率都有较大的影响,同时,系统容量与输出信噪比和数据传输速率有关并趋于定值。  相似文献   
992.
Ding  Ji-Feng 《Quality and Quantity》2009,43(4):553-570
The main purpose of this paper is to apply fuzzy quality function deployment (QFD) model to identify solutions of service delivery system (SDS) for port of Kaohsiung from the viewpoints of customers. At first, to facilitate the main issue of the QFD problem, however, the ‘what’ question of customer needs and ‘how’ problem of the services have to be made, which are two major components and be emphasized on the house of quality (HOQ) matrices. In conjunction with fuzzy sets theory, hence, the systematic procedures using fuzzy QFD were proposed in this paper. Subsequently, a case study for port of Kaohsiung demonstrated the systematic appraisal process for identifying solutions of SDS. The results of empirical study show that (1) 10 key factors are deemed as to have priority to improve the quality of SDS for Kaohsiung port; and (2) eight feasible solutions for improving service quality performance are identified. Moreover, it is suggested that port Authority of Kaohsiung should listen attentively the voice of customers and emphasize on exploiting these customer requirements effectively. And then develop the ‘how’ issues of profiles of solutions, which should continuously strengthen the perspectives of customer, internal business process, and learning and growth, respectively.  相似文献   
993.
994.
PLM education in production design and engineering by e-Learning   总被引:1,自引:1,他引:0  
These days more attention is being paid to Product Lifecycle Management (PLM) using a technique for managing total product planning, design, manufacturing, sales, and disposal. We researched business processes and education curriculum of the PLM system in manufacturing businesses. We designed the curriculum of PLM education and developed part of a lesson. Most importantly, e-Learning is shown to be an effective tool for achieving educational objectives. We found that not only knowledge and theory but also practical education methods using case studies in an e-Learning environment are necessary for human resources to develop effective PLM.  相似文献   
995.
Optimal safety stock levels of subassemblies and manufacturing components   总被引:4,自引:2,他引:2  
In order to control the time to market and manufacturing costs, companies produce and purchase many parts and components before receiving customer orders. Consequently, demand forecasting is a critical decision process. Using modular product design and super bills of materials are two effective strategies for developing a reliable demand forecasting process. They reduce the probability of stockouts in diversified production contexts. Furthermore, managing and controlling safety stocks for pre-assembled modules provide an effective solution to the problem of minimizing the effects of forecast errors. This paper develops, evaluates, and applies innovative cost-based analytical models so that the optimal safety stock of modular subassemblies and components in assembly to order and manufacturing to order systems, respectively, can be rapidly quantified. The implementation of the proposed models in two industrial case applications demonstrates that they significantly reduce the safety stock inventory levels and the global logistical cost.  相似文献   
996.
根据美军标MIL-STD-188-141A的规定,8FSK信号的解调是短波自动链路建立(ALE)系统的一项关键技术。通过把图像分割和聚类分析方法应用于8FSK信号的频谱分析,提出了基于模式识别的解调算法。测试结果表明,该算法对白噪声不敏感。  相似文献   
997.
刍议企业并购后的整合   总被引:1,自引:0,他引:1  
企业并购后的整合是企业并购成功的关键 ,而且是比完成并购交易要复杂和困难的工作。根据并购后整合的策略 ,提出了一个并购后整合的程序模型 ,并且分析了导致整合失败的可能原因 ,以期对并购后的整合有新的认识。  相似文献   
998.
蒋遐 《嘉兴学院学报》2006,18(2):110-112,142
“A就A在B(上)”句式是活跃在口语中的常用句式。该文从句法、语义平面上对该句式进行分析,首先从句法上分析能进入这个框架的“A”和“B”的性质。然后分析其语义,该句式既可以表示范围,也可以表示原因,还可以表示条件。  相似文献   
999.
The goal of sustainoble development is to preserve sustainabitity trod simultaneously prevent catastrophe in a man-land .system. However, almost all the existing approaches to assessing sustainable development are to measure the sustainability. namely appraise from the obverse side of the sustainable development. So it seems necessary to attack the same task on the reverse, namely to measure the passibility of eatostrophe. In this paper, with a case study of Tianjin, China. we employ catastrophe theory and models to integrate Tianjin's sustainable development indicators, and then deduce the catastrophe risk index ( CRI) to present the level of catastrophic possibility in the city. Applying catastrophe theory, is a new strategy to assess sustainable development and shows great practical significance, especially for those developing regions or countries, who always give more priority to their economy and therefore have more obligation to make sure whether their social economic activities might bring forth any ecological environment catastrophe. Besides, being both qualitative and quantitative, the approach could be employed to explore not only static characteristics bat also dynamic mechanism of man-land system. Although our work is only a maiden attempt and still calls for further effort to improve it, the case study of Tianjin in this paper would assure as the great promising future to apply, catastrophe theory to sustoinable devetopment modeling,  相似文献   
1000.
第三代移动通信系统 (3G)的第二阶段是采用IP传送网 ,服务质量 (QoS)是极其重要的问题。在讨论基于IP的 3G中QoS体系结构、业务QoS要求基础上 ,重点研究QoS控制原理和区分服务的实现 ,并得出一些有参考价值的结论。  相似文献   
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