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本文通过对系统中顾客数设置门限N,考虑研究了服务台的服务速度依门限发生变化且当服务台未服务顾客(休假或故障)时到达顾客仅以概牢p进入系统的多重休假可修M/G(M/G)/1排队系统。通过L-变换、母函数以及补充变量方法得到了队长分布的瞬态解、稳态解及一些可靠性结果,并指出当两个服务速度相等时该模型与前人研究的M/G/1(E,MV)排队一致。 相似文献
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在本文中,我们推广了带有休假的服务台不稳定的闸门服务M/G/1排队模型.当一个假期结束时,服务台发现系统为空,则服务台将启动一个随机长度的闲期.如果在闲期内有顾客到达,则服务台立即为该顾客服务;否则,当闲期结束后服务台不再等待而是接续另一个假期.在服务期的任何时间内服务台都有可能发生毁坏,毁坏到达是一个Possion过程,服务台的维修时间服从一般分布.在关于M/G/1排队系统现有结果的基础上,通过概率分析,应用母函数和LST得出了稳态下队长和等待时间的随机分解公式以及平均队长和平均等待时间. 相似文献
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在过去的二十年里,休假排队系统已经得到了广泛的研究.在各种休假排队模型中,在休假期内服务台是完全停止为顾客服务的.为了更客观地反映现实情况,本文在单重休假GI/M/1排队系统的基础上引入了在休假时服务台仍可低速服务而不是完全停止服务的工作休假策略和启动时间策略.对此模型的分析,我们重点关注顾客到达前夕时刻系统的状态,运用矩阵几何解方法得到了该系统的状态转移概率矩阵,并以概率矩阵为基础求出了系统的稳态平均队长和顾客的平均等待时间. 相似文献
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带关闭期的随机N-策略的M/G/1排队系统 总被引:1,自引:1,他引:0
本文通过向量Markov过程方法研究了带关闭期的随机N-策略M/G/1系统的排队指标.证得了系统达到稳态平衡的充要条件.并且在系统达到平衡时,讨论了稳态队长、等待时间、休假期、闲期,以及一个顾客被服务完之后系统中留下的队长和刚进入系统的顾客看到系统中的队长. 相似文献
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考虑服务台的启动由服务台闲期所有到达的服务时间累积之和(即顾客即将被服务的时间累积量)控制的离散时间批到达GeoX/G/1排队服务系统。顾客成批到达系统,当顾客的被服务时间累积量超过某个非负整数D时,服务台立刻为顾客提供服务直到忙期结束(此策略被称为D策略)。该模型可为无线传感网络的从业者提供一些理论基础。首先,在准备工作中,讨论了忙期开始时刻的顾客数、服务时间累积量以及服务台的忙期和闲期分布;然后,通过闲、忙期到达顾客的分类和概率分析方法,研究了系统的离去时刻稳态队长和任意时刻n+的稳态队长分布的概率母函数。作为特例,分析得到了离散时间GeoX/G/1排队和D策略离散时间Geo/G/1排队的队长分布结果。最后,模拟分析了一类无线传感节点,并在数值上获得了节点的最低能耗。 相似文献
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In this paper, a gate service Geom/G/1 queue system with single vacation is analyzed. Firstly, a gate service policy and single
vacation are introduced in detail, the expected number of customers in the system at the beginning instant of a service period
is obtained. Next, the Probability Generating Function (P.G.F.) of the stationary queue length is obtained by using regeneration
cycle approach. Then the P.G.F. of the waiting time is derived under the condition of the independence between the arrival
process and the waiting time. Moreover, the P.G.Fs. of the service period, the vacation period and the idle period are obtained,
and the mean length of three periods are also obtained. Cost model is formulated to determine the optimal expected vacation
length. Finally, based on numerical results, the relations of the performance measures and traffic intensity are discussed. 相似文献
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Chiahon Chien 《IIE Transactions》1998,30(3):267-272
Conventional wisdom suggests that a fast single-server queue is preferable to a number of slower single-server queues. The rationale is that if the service rate of the superposed queue is the sum of the service rates of the individual queues, then the average waiting time for the superposed queue is smaller than the weighted average waiting time of the individual queues. This argument, however, assumes that the service time of the customers is perfectly scalable. Unfortunately, this assumption rarely holds in reality. In this paper we analyze the superposition of M/G/1 queues. We assume that there are scalable and unscalable components in the service time. On the basis of the criteria of average waiting time and average response time, we derive necessary and sufficient conditions for whether the superposition of queues is preferable. Examples of magnetic rotational disks are given to illustrate our findings. 相似文献
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本文研究了带有止步和中途退出的多重休假排队系统模型,该排队模型的稳态概率已在我们的另一篇文章中给出.本文的目的是在稳态概率的基础上推导系统的稳态等待时间分布.通过对进入系统的顾客可能中途退出的不同情况的概率分析,我们分别在服务员忙和休假的情况下得到了进入系统并接受服务的顾客的稳态条件等待时间分布,进而得到了进入系统并接受服务的顾客的稳态条件等待时间的概率密度. 相似文献
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目的 针对作用于人的直接接触类服务设计,通过强化服务各步骤持续时长在服务蓝图中的可视化呈现效果,帮助设计师更有效地识别服务优化机会点,做出更有依据的设计决策,改进服务体验。方法 以服务蓝图工具为基础,首先通过文献研究法厘清服务蓝图的演进过程及研究现状,发现现有的服务蓝图工具没有考虑时间要素对服务质量的影响;其次通过引入甘特图的时间可视化表达形式,对服务蓝图进行改良;最后通过“某医院门诊患者就医服务”案例验证新工具的可靠性与合理性。结果 通过可用性定量工具评估了新工具的有效性、用户满意度和效率。在保留服务蓝图原有功能的基础上,针对直接作用于人的有形服务构建了时间轴服务蓝图工具。结论 时间轴服务蓝图有利于设计师明确服务中单个步骤持续时长对体验优化机会的影响,更准确地捕捉体验优化的机会点,从而提升服务质量,改善有形服务的用户体验。 相似文献
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售后现场服务排队近似M/G/m模型仿真 总被引:3,自引:0,他引:3
应用状态相关现场服务排队近似理论,分别建立基于客户服务代表最早空闲时间和客户服务代表最快响应时间的仿真模型.其M/M/m仿真结果接近经典M/M/m模型的准确值;M/G/m仿真结果显示后一模型比前一模型更加优越.依据最快响应时间调度客户服务代表可以有效地提升售后现场服务质量. 相似文献
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Gaigerov B. A. Elkin G. A. Zagirova E. G. Kostromin V. P. Koshelyaevskii N. B. Pushkin S. B. 《Measurement Techniques》2005,48(1):5-15
The structure of the standard time and frequency basis of the State Service for Time and Frequency (SSTF) of Russia is described. Information is given for the equipment make-up for the state primary standard of time and frequency (STFS) of the Russian Federation and secondary standards (SS) of the STFS. The most important metrological characteristics of the STFS and SS are provided.Translated from Izmeritelnaya Tekhnika, No. 1, pp. 12–18, January, 2005 相似文献
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Frantisek Lopot Bohdan Nejedlý Sylvie Sulková 《Hemodialysis international. International Symposium on Home Hemodialysis》2004,8(1):39-44
Quotidian or “daily" hemodialysis (DHD) is practiced in widely differing schedules. Yet all those schedules are reported to significantly ameliorate clinical outcome of patients. It is, however, not clear what is the actual cause of this amelioration. Rational possibilities include increased overall dialysis dose and increased weekly time. Conventional mathematical approaches (Kt/Vurea concept, equivalent renal clearance) cannot be used to study those issues because they do not consider number of dialysis per week and thus ignore the issue of treatment schedule “unphysiology.” The time average concentration/time average deviation (TAC/TAD) concept may well be used to visualize impact of treatment schedule on both plasma urea profile statics (TAC) and dynamics (TAD). The concept may further help to stratify studies for elucidation of the key factors of clinical outcome improvement seen on DHD. Actual physiologic mechanisms responsible for this improvement are to be sought among those with having derivative component (i.e., reacting to the rate of a change rather than to the magnitude of the change). It should, however, be kept in mind that the TAC/TAD concept is able to assess unphysiology of a treatment schedule, not unphysiology of a single treatment session. 相似文献
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An M/Ez/1 queue (i.e. a single-server queue having a Poisson arrival process and weighted-sum Erlangian service) can approximate a wide range of queueing systems quite closely. For this system a practical computational scheme is developed for determining (1) the expected amount of time the server is idle in the interval (0, t] and (2) the expected waiting time of a customer arriving at time t. The initial service load can be specified arbitrarily. Sample results and computer time requirements are also discussed. 相似文献