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91.
Evsey Morozov 《Queueing Systems》2007,56(3-4):157-168
We consider a multiserver retrial GI/G/m queue with renewal input of primary customers, interarrival time τ with rate
, service time S, and exponential retrial times of customers blocked in the orbit. In the model, an arriving primary customer enters the system
and gets a service immediately if there is an empty server, otherwise (if all m servers are busy) he joins the orbit and attempts to enter the system after an exponentially distributed time. Exploiting
the regenerative structure of the (non-Markovian) stochastic process representing the total number of customers in the system
(in service and in orbit), we determine stability conditions of the system and some of its variations. More precisely, we
consider a discrete-time process embedded at the input instants and prove that if
and
, then the regeneration period is aperiodic with a finite mean. Consequently, this queue has a stationary distribution under
the same conditions as a standard multiserver queue GI/G/m with infinite buffer. To establish this result, we apply a renewal technique and a characterization of the limiting behavior
of the forward renewal time in the (renewal) process of regenerations. The key step in the proof is to show that the service
discipline is asymptotically work-conserving as the orbit size increases. Included are extensions of this stability analysis
to continuous-time processes, a retrial system with impatient customers, a system with a general retrial rate, and a system
with finite buffer for waiting primary customers. We also consider the regenerative structure of a multi-dimensional Markov
process describing the system.
This work is supported by Russian Foundation for Basic Research under grants 04-07-90115 and 07-07-00088. 相似文献
92.
结构的全过程设计优化 总被引:5,自引:0,他引:5
建立了结构生命期内的设计优化模型。根据该模型,不仅可以得到结构的最优设计-维修策略,而且可以得以结构的寿命期。对在役结构,给出当前结构的剩余承载力,模型将给出结构以后的最优维修决策。该模型的优点在于理论简单易懂,计算方便,便于实际应用。 相似文献
93.
检验检测服务模式发展滞后于检验检测行业发展的重要原因之一就是缺乏针对于服务模式的理论定义。采用概念分析法,以服务模式的定义和检验检测行业的服务特点为逻辑,研究了相关的代表性理论,认为服务模式主要由服务的基本要素和服务的商业模式两方面的内容组成,并深入探讨了检验检测的服务模式,提出了构建检验检测服务模式这一概念的重要意义。 相似文献
94.
The life analysis of engine components needs to take into account the residual stress relaxation induced by cyclic service loads. The paper recalls a new class of constitutive equations for cyclic viscoplasticity, using a series of kinematic hardening models with thresholds. The equations are introduced within a recently enlarged thermodynamic framework. Some attention is focused to the relations with multisurface approaches and to a specific determination procedure of the model parameters. The new model is applied to the calculation of the near surface residual stress relaxation after shot peening, when the structure is submitted to cyclic service loads. The simulated stabilized residual stresses are in good accordance with experimental results obtained on an N18 disk alloy at 650°C. In comparison, the classical model without threshold predicts the complete vanishing of the residual stresses, which is not satisfactory. 相似文献
95.
In a service operation where worker requirements have to be determined for short scheduling time periods with nonstationary customer demand, the assumptions necessary for applying steady-state solutions to elementary queueing models are usually violated. This paper describes a simulation study of the behavior of such a service operation. The results are compared with the steady-state solutions to a queueing model where individual scheduling time periods are assumed to be independent. It is found that if the system utilization is below a derived maximum value (based on a service level criterion), then the steady-state solutions are robust enough to explain the behavior of the system and can be used to schedule worker requirements. 相似文献
96.
Yufei Yuan 《European Journal of Operational Research》1996,90(3):536
This paper introduces a special matching problem, the stable residence exchange problem, originated from the need for residence exchange in China. The problem involves families wishing to exchange their residences based on their preferences. The stability of exchange is defined and the problem can be formed as a special case of trading indivisible goods with preferences. The solution method and the properties of the solution are discussed and the factors that may affect the performance of the residence exchange are investigated through computer simulation. Finally, the application considerations are addressed. 相似文献
97.
98.
99.
在一定假设条件下,建立了投资者对信息服务的价值分析和最佳投资的理论模型,并对文[1]中的结论进行修正,得到了与实际更加符合的结论. 相似文献
100.
This paper considers polling systems with an autonomous server that remains at a queue for an exponential amount of time before
moving to a next queue incurring a generally distributed switch-over time. The server remains at a queue until the exponential
visit time expires, also when the queue becomes empty. If the queue is not empty when the visit time expires, service is preempted
upon server departure, and repeated when the server returns to the queue. The paper first presents a necessary and sufficient
condition for stability, and subsequently analyzes the joint queue-length distribution via an embedded Markov chain approach.
As the autonomous exponential visit times may seem to result in a system that closely resembles a system of independent queues,
we explicitly investigate the approximation of our system via a system of independent vacation queues. This approximation
is accurate for short visit times only.
相似文献