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排序方式: 共有535条查询结果,搜索用时 31 毫秒
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LI Mei-ling YUAN Chao-wei LI Lin YANG Rui-zhe .School of Information Communication Engineering Beijing University of Posts Telecommunications Beijing China .School of Electronics Information Engineering Taiyuan University of Science Technology Taiyuan China .College of Electronic Information Control Engineering Beijing University of Technology Beijing China 《中国邮电高校学报(英文版)》2011,(4):39-44
In cooperative spectrum sensing,more secondary user makes more opportunity for detecting the vacant spectrums,which resulting the spectrum utilization improved,however much bandwidth would be occupied for sending the local observation results,inducing the reduced secondary throughput.In this paper,an adaptive algorithm for selecting detection threshold was proposed,where the maximized secondary throughput can always be achieved while assuring sufficient protection to primary user,regardless of the number of... 相似文献
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Fluid-based Slotting Optimization for Automated Order Picking System with Multiple Dispenser Types 总被引:1,自引:0,他引:1
LIU Peng WU Yaohua ZHOU Chen XU Na School of Control Science Engineering Sh ong University Jinan China School of Industrial Systems Engineering Georgia Institute of Technology Atlanta GA USA Business School Sh ong Jianzhu University Jinan China 《机械工程学报(英文版)》2011,(4):529-538
Slotting strategy heavily influences the throughput and operational cost of automated order picking system with multiple dispenser types, which is called the complex automated order picking system (CAOPS). Existing research either focuses on one aspect of the slotting optimization problem or only considers one part of CAOPS, such as the Low-volume Dispensers, to develop corresponding slotting strategies. In order to provide a comprehensive and systemic approach, a fluid-based slotting strategy is proposed in this paper. The configuration of CAOPS is presented with specific reference to its fast-picking and restocking subsystems. Based on extended fluid model, a nonlinear mathematical programming model is developed to determine the optimal volume allotted to each stock keeping unit (SKU) in a certain mode by minimize the restocking cost of that mode. Conclusion from the allocation model is specified for the storage modules of high-volume dispensers and low-volume dispensers. Optimal allocation of storage resources in the fast-picking area of CAOPS is then discussed with the aim of identifying the optimal space of each picking mode. The SKU assignment problem referring to the total restocking cost of CAOPS is analyzed and a greedy heuristic with low time complexity is developed according to the characteristics of CAOPS. Real life application from the tobacco industry is presented in order to exemplify the proposed slotting strategy and assess the effectiveness of the developed methodology. Entry-item-quantity (EIQ) based experiential solutions and proposed-model-based near-optimal solutions are compared. The comparison results show that the proposed strategy generates a savings of over 18% referring to the total restocking cost over one-year period. The strategy proposed in this paper, which can handle the multiple dispenser types, provides a practical quantitative slotting method for CAOPS and can help picking-system-designers make slotting decisions efficiently and effectively. 相似文献
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FANG Hua HAN Jianghong LIU Xiaoping School of Computer Information Hefei University of Technology Hefei China Engineering Research Center of Safety Critical Industrial Measurement Control Technology of Ministry of Education China School of Electrical Engineering Automation China Received February revised October accepted February published electronically February... 《机械工程学报(英文版)》2011,(6):999-1006
Recently automotive nets are adopted to solve increasing problems in automotive electronic systems.Technologies of automotive local area network from CAN and LIN can solve the problems of the increasing of wire bunch weight and lack in module installation space.However,the multilayer automotive nets software becomes more and more complex,and the development expense is difficult to predict and to keep in check.In this paper,the modeling method of hierarchical automotive nets and the substitution operation based on object-oriented colored Petri net(OOCPN) are proposed.The OOCPN model which analyzes the software structure and validates the collision mechanism of CAN/LIN bus can speed the automobile system development.First,the subsystems are divided and modeled by object-oriented Petri net(OOPN).According to the sets of message sharing relations,the message ports among them are set and the communication gate transitions are defined.Second,the OOPN model is substituted step by step until the inner objects in the automotive body control modules(BCM) are indivisible and colored by colored Petri net(CPN).And the color subsets mark the node messages for the collision mechanism.Third,the OOCPN model of the automotive body CAN/LIN nets is assembled,which keeps the message sets and the system can be expanded.The proposed model is used to analyze features of information sharing among the objects,and it is also used to describe each subsystem real-time behavior of processing messages and implemental device controllers operating,and puts forward a reasonable software framework for the automotive body control subsystem.The research can help to design the communication model in the automotive body system effectively and provide a convenient and rapid way for developing the logical hierarchy software. 相似文献
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基于容错度自适应支持向量机的液压泵故障诊断 总被引:2,自引:0,他引:2
针对已有在线故障诊断方法在数据量大、噪声强条件下分类速度较低、分类精度不够高等问题,结合液压泵故障类别数目大、工作环境恶劣的特点,提出了一种适用于混凝土泵车液压泵在线诊断的状态识别算法——容错度自适应支持向量机。该方法主要从四个方面对分类速度做了改进:①引入容错度因子进行模型训练;②优先选择能将某一类故障样本单独分离出来的二分类器;③在满足②的基础上选择平均支持向量机少的分类器;④引入增量学习算法对参数进行自适应调整,提高多故障诊断中对新故障类别和新故障数据的适应性,保证系统的分类精度。通过对混凝土泵车的液压泵故障诊断,证明了该方法在明显提高分类速度的同时保证了较高的分类精度。 相似文献
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本文运用VB6.0设计钻井地面监控系统,它实现的主要功能是实时的传送钻井信息,并用MSChart控件对钻井信息进行历史趋势曲线的设计与绘制。 相似文献
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对国产冻干麻疹活疫苗进行了加速热稳定性试验,结果在37℃、41℃及45℃的下降率分别为0.0245。0.0599及0.1 435 TCID_(50)/ml/天,三者差异十分显著;半衰期分别为12.3天。5.0天及2.1天,表明疫苗的稳定性有所提高,但与文献报道的差距尚大,比较不同基础滴度疫苗在37℃下的热稳定性,结果下降率及半衰期未见明显差异。 相似文献
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综述了单螺杆挤出机内聚合物熔体层流混合机理的研究进展,对提高混合的措施进行了分析总结,指出了进一步强化混合效果的方法。 相似文献