A NEW FIXED POINT THEOREM FOR CONE MAPS AND ITS APPLICATIONS

1IntroductionLetEbearealBanachspace.AnonemptyconvexclosedsetPCEiscalledaconeinEifitsatisfiesthefollowingtwoconditionsf(i)xEP,A20impliesAxEP,(n)xEP,--xEPimpliesx=0.AconePiscalledsolidifitcontainsinteriorpoints,i.e.,P/gi.TheconePinEdefinesapartialorderingx5…     

一类2阶边值问题的分歧点

本文考虑以下２阶边值问题：其中．在关于Ａ，Ｂ；Ｐ，Ｑ，ｆ的一定条件下，证明了以上问题存在分歧点．所用的主要工具是Ｋｒａｓｎｏｓｅｌｓｋｉｉ的局部分歧定理与ＫｒｅｉｎＲｕｔｍａｎ定理．     

Periodic maintenance and repair rate control in stochastic manufacturing systems

In this paper, we consider a periodic preventive maintenance, repair, and production model of a flexible manufacturing system with failure-prone machines, where the control variables are the repair rate and production rate. We use periodic preventive maintenance to reduce the machine failure rates and improve the productivity of the system. One of the distinct features of the model is that the repair rate is adjustable. Our objective is to choose a control process that minimizes the total cost of inventory/shortage, production, repair, and maintenance. Under suitable conditions, we show that the value function is locally Lipschitz and satisfies an Hamilton-Jacobi-Bellman equation. A sufficient condition for optimal control is obtained. Since analytic solutions are rarely available, we design an algorithm to approximate the optimal control problem. To demonstrate the performance of the numerical method, an example is presented.Research of this author was supported by the Natural Sciences and Engineering Research Council of Canada, Grant OGP0036444.Research of this author was supported in part by the University of Georgia.Research of this author was supported in part by the National Science Foundation, Grant DMS-92-24372.     

环的自映射的最少周期点数

设Ｘ是一个紧致连通的ＡＮＲ＇ｓ，ｆ：Ｘ→Ｘ是连续映射。于是ｆ有Ｎｉｅｌｓｅｎ型数，ＮＦｎ（ｆ），它是数集｛＃Ｆｉｘ（ｇ＾ｎ）ｇ－ｆ｝的下界。本文在Ｘ是环时，给出ＮＦｎ（ｆ）是该数集的下确界，即存在连续映射ｇ＝ｆ，使得＃Ｆｉｘ（ｇ＾ｎ）＝ＮＦｎ（ｆ）的一个充分条件。     

The inspection paradox in renewal-reward processes

To explore the inspection paradox in the context of a renewal-reward process, we obtain asymptotic expressions for the mean and distribution function of the reward associated with the spread (total life) of the process. These results also yield a simplified demonstration of the elementary renewal-reward theorem.     

Inventory control using a service constraint on the expected customer order waiting time

In this paper an analytical model is presented which permits the determination of the minimal inventory reorder point subject to (a) a maximum specified expected customer order waiting time or (b) a maximum specified probability of a customer order waiting more than a predetermined time span. The probability distribution of the customer order waiting time is determined for an arbitrary demand distribution (e.g. normal, gamma or exponential) and under stochastic replenishment lead time conditions by use of arguments from renewal theory. The results established can be used for the customer-oriented control of inventory policy as well as for the analysis of multi-echelon inventory systems.     

Some results for secondary processes generated by a poisson process

We obtain the moment structure of a general class of random variables generated by a Poisson process. We then apply these relationships to several applied probability models. Among these are queues, counter models and low density traffic flow.     

Point processes and multivariate extreme values

A new model for point processes is developed which assumes that the interarrival times are exponentially distributed and follow joint multivariate extreme value distributions. It is shown that such processes may arise via natural generating procedures, and that, under very weak assumptions, that they can be approximated as closely as desired by appropriate finite models.     

Brownian diffusion in a nonuniform gas

An analysis is made of the effects on the diffusion of Brownian particles whose Knudsen number is large compared to unity, of nonuniformities in the host gas. As examples, in one type of nonuniformity of the host gas, the Chapman-Enskog velocity distribution function for the gas molecules is used; in the other, the host gas is a free-molecule Couette flow. In both cases, a new force on the Brownian particles appears. Two techniques are used (extending Kramers' method and utilizing the Chapman-Enskog method) to transform the new Fokker-Planck equation into generalized Smoluchowski and convective diffusion equations. In these equations, the diffusion coefficient appears as a second-order tensor. Thus, it is demonstrated that Brownian diffusion in a nonuniform gas is anisotropic.The work of Slinn was financially supported in part by Battelle Memorial Institute and in part by U.S. Atomic Energy Commission Contract AT(45-1)-1830. The work of Shen was supported in part by U.S. Air Force Office of Scientific Research Contract 49(638)-1346.