This paper deals with a discrete-time Geo/Geo/1 queueing system with working breakdowns in which customers arrive at the system in variable input rates according to the states of the server. The server may be subject ...This paper deals with a discrete-time Geo/Geo/1 queueing system with working breakdowns in which customers arrive at the system in variable input rates according to the states of the server. The server may be subject to breakdowns at random when it is in operation. As soon as the server fails, a repair process immediately begins. During the repair period, the defective server still provides service for the waiting customers at a lower service rate rather than completely stopping service.We analyze the stability condition for the considered system. Using the probability generating function technique, we obtain the probability generating function of the steady-state queue size distribution.Also, various important performance measures are derived explicitly. Furthermore, some numerical results are provided to carry out the sensitivity analysis so as to illustrate the effect of different parameters on the system performance measures. Finally, an operating cost function is formulated to model a computer system and the parabolic method is employed to numerically find the optimum service rate in working breakdown period.展开更多
To collect and share information of projects or products and make it consistent and correct so that the quality and costs of projects can be effectively controlled,an integrative project architecture integrating diffe...To collect and share information of projects or products and make it consistent and correct so that the quality and costs of projects can be effectively controlled,an integrative project architecture integrating different types of breakdown structures is necessary.In this paper,the international research status on work breakdown structure(WBS)was analyzed,and an integrative project architecture for commercial aero-engines was designed,where product breakdown structure(PBS),WBS,organization breakdown structure(OBS)and cost breakdown structure(CBS)were integrated and built.And the architecture was applied in information systems.A transfer from technological views of complex products through their lifecycles to management views has been realized with this standardized architecture,thus development tasks and costs can be controlled.展开更多
基金Supported by the National Natural Science Foundation of China(71571127)the Training Fund Program of Excellent Paper of Sichuan Normal University([2016]4-1)
文摘This paper deals with a discrete-time Geo/Geo/1 queueing system with working breakdowns in which customers arrive at the system in variable input rates according to the states of the server. The server may be subject to breakdowns at random when it is in operation. As soon as the server fails, a repair process immediately begins. During the repair period, the defective server still provides service for the waiting customers at a lower service rate rather than completely stopping service.We analyze the stability condition for the considered system. Using the probability generating function technique, we obtain the probability generating function of the steady-state queue size distribution.Also, various important performance measures are derived explicitly. Furthermore, some numerical results are provided to carry out the sensitivity analysis so as to illustrate the effect of different parameters on the system performance measures. Finally, an operating cost function is formulated to model a computer system and the parabolic method is employed to numerically find the optimum service rate in working breakdown period.
文摘To collect and share information of projects or products and make it consistent and correct so that the quality and costs of projects can be effectively controlled,an integrative project architecture integrating different types of breakdown structures is necessary.In this paper,the international research status on work breakdown structure(WBS)was analyzed,and an integrative project architecture for commercial aero-engines was designed,where product breakdown structure(PBS),WBS,organization breakdown structure(OBS)and cost breakdown structure(CBS)were integrated and built.And the architecture was applied in information systems.A transfer from technological views of complex products through their lifecycles to management views has been realized with this standardized architecture,thus development tasks and costs can be controlled.
