Alan Stulman

Optimizing robot's service movements: a one dimensional case

Abstract In this paper we present a simulation based analysis of a service robot operating in a textile mill. The robots function is to locate and service the operating units which require the servicing. The main purpose of the analysis is to determine the “best” movement decision for the robot in each instance. We present a simple simulation experiment which clearly illustrates that an increase in production output can be realized with the help of modestly sophisticated decision rules for the robots movement.

Age replacement in the presence of inventory constraints

Abstract Many authors in the literature have treated the age replacement problem and its various modifications. One generally is asked to assume the ability of a system to provide instantaneous replacements whenever needed. This is often not a very realistic assumption. In this paper we will examine one recent age replacement model when replacements are constrained by two simple inventory models.

Priority centralization of the one period multi-location inventory system

In this paper, we will examine a multi-center one-period inventory system. The usual penalty cost for being out of stock will be replaced by an assurance of service constraint at each location. That is, we will constrain our inventory size to meet a specific maximum probability of being out of stock at each location. The centralized system we shall propose will define a priority rule which will cause us to satisfy the entire demand of high priority locations before we begin satisfying the demands of lower priority locations. This will allow us to find a minimum initial inventory level for the centralized system that will meet all of the assurance of service constraints. We will look at the special case where the variance of the total demand of several locations is non-decreasing in locations included in the total. In this case, we will show the computations required for finding the optimal centralized priority system are minimal. Finally, we will show that such a system is superior to a decentralized system.

The facility location problem when the underlying distribution is either dominated or dominating

The theory of choices involving Risk is used to solve some classes of the “Today” maximin and minimax one facility location problems. Solutions are shown when the underlying demand distribution is symmetric and unimodal.

Optimal mining of a stratiform phosphate field

Abstract An optimal control model is developed to determine optimal surface mining operations of a phosphate field. This field1806 1040 contains both a bottom layer and a top layer of phosphates. The deeper the digging, the more phosphates will be exploited but the higher will be the cost per ton. If the bottom layer is not exploited, it will be lost to future production. The methods of Optimal Control Theory are applied and produce expressions which can be evaluated for the optimal scheduling around the phosphate field.

Sample Size Limit When Sampling From a Nonhomogeneous Mixture

The variance associated with a random sample taken from a nonhomogeneous mixture is highly dependent on the degree of nonhomogeneity. In this paper we explore the upper limit on the variance with the aid of optimal control techniques. A specific numeric..