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101.
就具有最简单结构的抽象垄断服务系统的基本特性及其公共损耗的费用分摊问题建立了较为完整的公平性与合理性公理体系.同时,利用边际损耗原则导出了一类满足公理组的费用分摊方法,并将所得结论应用于电力系统有功网损费用分摊问题,从理论上统一了现有的几类主要的分摊方法.分析结论表明:损耗结构分析和费用分摊原则的确定在本质上从属于不同层次的问题.特别地,对不分明损耗而言:它们还是不可分割的统一体.对这一类问题进行描述必须考虑综合运用数学、社会学、经济学和方法论原则. 相似文献
102.
一个具有随机丢弃分组机制且分组成批到达的GI~X/M/1/N排队系统 总被引:3,自引:0,他引:3
汪浩 《数学的实践与认识》2005,35(9):113-120
利用排队论中输入流稀疏化的方法,在标准的GIX/M/1/N排队系统中嵌入网络交换设备随机丢弃分组的机制,建立了一个具有随机丢弃分组机制的扩充的GIX/M/1/N排队系统,并讨论了该排队系统的分组丢失率、系统利用率、队列长度的均值/方差、平均等待时间等性能评价指标. 相似文献
103.
A symmetric queue is known to have a nice property, the so-called insensitivity. In this paper, we generalize this for a single node queue with Poisson arrivals and background state, which changes at completion instants of lifetimes as well as at the arrival and departure instants. We study this problem by using the decomposability property of the joint stationary distribution of the queue length and supplementary variables, which implies the insensitivity. We formulate a Markov process representing the state of the queue as an RGSMP (reallocatable generalized semi-Markov process), and give necessary and sufficient conditions for the decomposability. We then establish general criteria to be sufficient for the queue to possess the property. Various symmetric-like queues with background states, including continuous time versions of moving server queues, are shown to have the decomposability.This author is partially supported by NEC C&C Laboratories. 相似文献
104.
SPA联系数是把研究对象各种测度联系起来加以系统性地描述、计算、分析的一种结构函数,其一般形式为a+bi+cj,用于城市第一产业、第二产业、第三产业相互联系和演化规律的研究有其合理和创新之处,其特点是把城市第一产业、第二产业、第三产业看成一个系统.用于大连产业结构演化规律研究后发现,大连市在1978~1999年20年间经历了稳定——剧烈调整——稳定这样三个阶段.在今后的10~20年间,对于第三产业的投资仍将处在首位. 相似文献
105.
Masakiyo Miyazawa 《Queueing Systems》1997,25(1-4):45-75
We consider characterizations of departure functions in Markovian queueing networks with batch movements and state-dependent
routing in discrete-time and in continuous-time. For this purpose, the notion of structure-reversibility is introduced, which
means that the time-reversed dynamics of a queueing network corresponds with the same type of queueing network. The notion
is useful to derive a traffic equation. We also introduce a multi-source model, which means that there are different types
of outside sources, to capture a wider range of applications. Characterizations of the departure functions are obtained for
any routing mechanism of customers satisfying a recurrent condition. These results give a unified view to queueing network
models with linear traffic equations. Furthermore, they enable us to consider new examples as well as show limited usages
of this kind of queueing networks.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
106.
本文运用2000年至2003安徽省17个城市的统计资料,运用比较分析法和回归分析法,从城市规模、产业聚集、要素聚集以及综合经济实力等方面,对安徽省17个地级城市的发展进行了分析。主要结论认为,近几年来安徽省城市化发展步伐加快,城市规模、产业聚集与城市综合经济实力三者关系密不可分。但安徽省在城市化过程中存在着城市空间规模外延式扩张多,注重城市内涵效益的发展不够的问题,而城市发展的首要任务是产业的发展,带动要素的聚集,进而促进城市化水平的提高。安徽省城市发展的关键是建立有利于城市化发展的聚集机制和政策环境。 相似文献
107.
各国信息产业综合水平的比较 总被引:2,自引:0,他引:2
使用因子分析法对世界 4 1个国家的信息产业发展作横向关联和时间纵向的综合水平比较 ,在定量分析的基础上 ,提出了自己的观点和看法。 相似文献
108.
We consider a polling model in which a number of queues are served, in cyclic order, by a single server. Each queue has its own distinct Poisson arrival stream, service time, and switchover time (the server's travel time from that queue to the next) distribution. A setup time is incurred if the polled queue has one or more customers present. This is the polling model with State-Dependent service (the SD model). The SD model is inherently complex; hence, it has often been approximated by the much simpler model with State-Independent service (the SI model) in which the server always sets up for a service at the polled queue, regardless of whether it has customers or not. We provide an exact analysis of the SD model and obtain the probability generating function of the joint queue length distribution at a polling epoch, from which the moments of the waiting times at the various queues are obtained. A number of numerical examples are presented, to reveal conditions under which the SD model could perform worse than the corresponding SI model or, alternately, conditions under which the SD model performs better than a corresponding model in which all setup times are zero. We also present expressions for a variant of the SD model, namely, the SD model with a patient server. 相似文献
109.
This article examines how performance-contingent pricing schemes with long-term statistical performance guarantees can be applied to many IT services. We study two forms of performance-contingent pricing, with rebate proportional to failure rate and fixed rebate for below-threshold performance. We show that threshold-performance contingency pricing can increase both profits and fairness (customers who receive higher benefits pay higher effective price) relative to standard pricing. But an even better solution is to offer a menu of performance guarantees: this can increase the firm’s profit and segment the market. Only service providers whose performance level is sufficiently better than the industry standard can benefit from this pricing mechanism. 相似文献
110.
J. Sztrik 《European Journal of Operational Research》1985,20(2):261-268
The aim of the present paper is to give the main characteristics of the finite-source queue in equilibrium. Here unit i stays in the source for a random time having general distribution function Fi(x) with density fi(x). The service times of all units are assumed to be identically and exponentially distributed random variables with means 1/μ. It is shown that the solution to this model is similar in most important respects to that for the M/M/r model. 相似文献