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排序方式: 共有182条查询结果,搜索用时 15 毫秒
1.
在设计一个新的灌溉配水系统时,渠道容量是一个不易确定的参数,因为农场用户提出供水的时间和水量通常是不确定的,取决于季节、气候、农作物种类等因素。渠道容量对灌溉投资和服务质量有重要的影响。提出运用排队理论确定渠道容量的大小。依据该理论,服务系统需提供的容量取决于将要达到的服务水平,以及顾客到达时间和服务时间的平均密度和分布规律。将灌溉渠道容量比作排队系统的服务能力。研究了指数分配和非指数分配模型及10个连续的灌溉周期。计算实例显示,同传统的Clement方程相比,该方法的结果相当可信。 相似文献
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不同于传统的网络,无线传感器网络能够协同地进行实时监测、感知和采集网络覆盖区域中监测对象的信息,并对其进行处理,处理后的信息通过无线方式传送,并以自组多跳的方式传送给观察者。路由协议的研究是无线传感器网络研究重点之一。蚁群算法是一种模仿自然界蚂蚁觅食的仿生算法,生物学家经过长期观察发现,蚂蚁总能够在巢穴和食物源之间找到一条最短路径。文中采用蚁群优化策略,给出了一种SMR多路径路由协议的改进算法ACO-SMR。该算法在保留SMR算法优点的基础上,进一步提高了资源利用率和路径稳定性,以及延长了网络生存时间。 相似文献
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David B. Ahn Won-Yeong Kim Kwon-Hyung Lee Seong-Sun Lee Seung-Hyeok Kim Sodam Park Young-Kuk Hong Sang-Young Lee 《Advanced functional materials》2023,33(18):2211597
Conventional power sources encounter difficulties in achieving structural unitization with complex-shaped electronic devices because of their fixed form factors. Here, it is realized that an on-demand conformal Zn-ion battery (ZIB) on non-developable surfaces uses direct ink writing (DIW)-based nonplanar 3D printing. First, ZIB component (manganese oxide-based cathode, Zn powder-based anode, and UV-curable gel composite electrolyte) inks are designed to regulate their colloidal interactions to fulfill the rheological requirements of nonplanar 3D printing, and establish bi-percolating ion/electron conduction pathways, thereby enabling geometrical synchronization with non-developable surfaces, and ensuring reliable electrochemical performance. The ZIB component inks are conformally printed on arbitrary curvilinear substrates to produce embodied ZIBs that can be seamlessly integrated with complicated 3D objects (including human ears). The conformal ZIB exhibits a high fill factor (i.e., areal coverage of cells on underlying substrates, ≈100%) that ensures high volumetric energy density (50.5 mWh cmcell−3), which exceeds those of previously-reported shape-adaptable power sources. 相似文献
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The use of rechargeable sensors is a promising solution for wireless sensor networks. On this type of network, mobile charging vehicles (MC) are used for charging sensors using wireless energy transfer (WET) technology. In on-demand charging, a sensor transmits a charging request to the service station, and the MC visits the sensor to transfer energy. The key disadvantages of utilizing MC-based WET are its high energy expenditure rate due to mobility, long service time, and slow charging rate. Because of these reasons, sensors deplete their energy and become dead before the MC reaches the requesting nodes to recharge. We have adapted a genetic algorithm-based partial charging scheme to serve the charging requests. Our objective is to improve the survival ratio of the network. Using comprehensive simulations, we analyze the performance of our proposed method and compare it to two other existing approaches. The simulation results demonstrate that our proposed algorithm improves the survival ratio by up to 20 % by developing a dynamic energy threshold function for transmitting charging requests from the sensors and a partial charging schedule using a genetic algorithm. 相似文献
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Lin-huang Chang Author Vitae Chun-hui Sung Author Vitae Author Vitae Yen-wen Lin Author Vitae 《Journal of Systems and Software》2010,83(12):2536-2555
In this paper we design and implement the pseudo session initiation protocol (p-SIP) server embedded in each mobile node to provide the ad-hoc voice over Internet protocol (VoIP) services. The implemented p-SIP server, being compatible with common VoIP user agents, integrates the standard SIP protocol with SIP presence to handle SIP signaling and discovery mechanism in the ad-hoc VoIP networks. The ad-hoc VoIP signaling and voice traffic performances are analyzed using E-model R rating value for up to six hops in the implemented test-bed. We also conduct the interference experiments to imitate the practical ad-hoc VoIP environment. The analyzed results demonstrate the realization of ad-hoc VoIP services by using p-SIP server. 相似文献
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基于社区云的按需个性化流程构建方法研究 总被引:1,自引:0,他引:1
针对传统流程模式在互联网应用的局限性,为提高Web服务发现组合能力,提出了社区云的概念,用社区云组织管理Web服务,可以屏蔽服务多样性和多变性带来的复杂性。研究了服务的抽取和社区云服务池的构建方法以及相应的组织和管理机制。在此基础上,构建了一种适用于个性化按需流程生成的云计算支撑平台框架,给出了各个部分的作用及相互间的关系。通过该平台自动生成个性化按需流程,并验证了流程的正确性。 相似文献
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