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971.
Srinivas Bollapragada Aparna Gupta Chaipat Lawsirirat 《European Journal of Operational Research》2007
Long-term service agreements (LTSAs) for the maintenance of capital-intensive equipments such as gas turbines and aircraft engines are gaining wide acceptance. A typical LTSA contract spans over a period of around 10 years making a manufacturer fully responsible for maintaining the customer equipment. In this paper, we address the management of a portfolio of such contracts from the manufacturer’s perspective. The goal is to meet all the service requirements imposed by the contracts while minimizing total cost incurred. We develop a deterministic integer programming model to generate the optimal maintenance schedules that minimize the total portfolio cost. We then propose two heuristic algorithms for the problem. 相似文献
972.
提出了综合业务数据库系统的设计方案,数据库系统的设计采用软件总线思想,模块化的设计,通过实现SCP,SDP,SMP,SCEP的功能,为用户提供标准的智能网业务,定制各种增值业务,并能满足下一代网络NGN的智能业务应用. 相似文献
973.
系统模拟做为一种定量分析的手段,在管理中发挥着重要的作用,对离散系统模拟方法进行了讨论,建立了一个随机服务系统的模型,并通过Excel对其进行模拟,最后对该系统的性能进行了分析. 相似文献
974.
本文讨论了由N个同型部件和一个服务设备组成的机器服务模型,在服务设备绝对可靠,或服务设备具有指数寿命,修理工对其修理的时间为PH分布,这两种情况下求得了系统的平稳概率分布,从而求得机器系统和服务设备的稳态可靠性指标,并证明了它们的首次失效时间均服从PH分布,服务设备和修理工的忙期亦服从PH分布. 相似文献
975.
本文在分析我国农村过剩劳动力状况的基础上,着重探讨了农村过剩劳动力转移到社会服务、个人服务业以及商业部门的前景,指出我国政府逐步取消户籍制度将有利于农村过剩劳动力向这些行业的转移。 相似文献
976.
To provide preferential protection for users while keeping good service utility, a preferential private recommendation framework ( named as PrefER) is proposed. In this framework, a preferential budget allocation scheme is designed and implemented at the system side to provide multilevel protection. And users' preference is utilized at the user side to improve recommendation performance without increasing users' burden. This framework is generic enough to be employed with other schemes. Recommendation accuracy based on the MovieLens dataset by the collaborative filtering schemes and PrefER are compared and analyzed. The experimental results show that PrefER can provide preferential privacy protection with the improvement of recommendation accuracy. 相似文献
977.
Mostafa Haghi Kashani Amir Masoud Rahmani Nima Jafari Navimipour 《International Journal of Communication Systems》2020,33(8)
In recent years, fog computing, a novel paradigm, has emerged for location and latency‐sensitive applications. It is a powerful complement for cloud computing that enables provisioning services and resources outside the cloud near the end devices. In a fog system, the existence of several nonhomogenous devices, which are potentially mobile, led to quality of service (QoS) worries. QoS‐aware approaches are presented in various parts of the fog system, and several different QoS factors are taken into account. In spite of the importance of QoS in fog computing, no comprehensive study on QoS‐aware approaches exists in fog computing. Hence, this paper reviews the current research used to guarantee QoS in fog computing. This paper investigates the QoS‐ensuring techniques that fall into three categories: service/resource management, communication management, and application management (published between 2013 and October 2018). Regarding the selected approaches, this paper represents merits, demerits, tools, evaluation types, and QoS factors. Finally, on the basis of the reviewed studies, we suggest some open issues and challenges which are worth further studying and researching in QoS‐aware approaches in fog computing. 相似文献
978.
Joy Lal Sarkar Chhabi Rani Panigrahi Bibudhendu Pati Apu Kumar Saha Abhishek Majumder 《International Journal of Communication Systems》2020,33(13)
Recent advancements in the area of Mobile Cloud Computing (MCC) have significantly contributed towards assisting mankind to handle varied types of emergency situations that may arise as a result of different natural calamities like earthquakes, floods, fire, etc, which may cause huge damage to public property and result in loss of wealth of the nation. In this work, we have proposed a mobile cloud assisted architecture that supports the multicloud and hybrid‐cloud environments, together with Cloud Probing Service (CPS) and Cloud Ranking Service (CRS). The proposed algorithm consumes data from the sensor nodes and offloads the data to the most suitable cloud. A three‐layered architecture has been proposed, and the anchor points facilitate in the creation of the interface between the different layers. The simulation results indicate that the proposed mobile cloud assisted architecture for handling emergency situations (MAAS) approach performs better than the baseline algorithms. 相似文献
979.
980.
自然灾害风险下区域应急储备设施选址可靠性研究 总被引:4,自引:0,他引:4
自然灾害发生时,为了保证区域应急储备系统的服务不被中断,考虑设施被破坏数目的发生概率并提供备份库存,以加强应急储备系统的可靠性。模型采用非支配排序遗传算法(NSGA-II)进行求解,产生一组选址决策方案。以四川省八大城市的人口及运输距离为输入数据的仿真结果表明,与一般模型比较,本文考虑可靠性的选址模型能更好抵御自然灾害造成的中断影响,并且能获得更优的应急响应满意度、多重覆盖或总成本的单目标值。因此,在地震等灾害的破坏风险下,该模型可成为应急储备设施可靠选址的有效工具。 相似文献