الفهرس 
Search problemsOnly 14 pages are availabe for public view
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Abstract
The study of the problem of search for lost target that are located or moving according to any random process is important .This problem has many applications such as searching for a mine on a battlefront whose extension may approximated by a straight line, searching for lost person on land or lost submarine and ship on or under the sea,searching for petrol or gas supply under ground. The aim of this study is to calculate the probability of detecting the lost target or the expected value of the effort used to detect the target and then we obtain the search plan which made the probability of detection is maximum or the cost of finding the target is minimum. Some problems of search may impose using more than one searcher,such as when we search for a valuable target (e.g a person) also, in some cases of search problems the cost of search will be reduced by using more than one searcher .In our study we use more than one searcher, and one searcher only. The thesis consists of four chapters: Chapter I It is just an introductory chapter ,it sets the stage for the coming chapters by accommodating some basic definitions and notifications,which will be used throughout this study also, it considered a collection of previous studies and different types of search problems. Chapter 2 This chapter consists of two parts; in the first part we assume that a target is located randomly on the line and it has a discrete distribution we obtain the optimal search plan to find this lost target when the searcher starts looking for the target from some point a0 + 0 also, we study the case when the lost target is located randomly on one of two disjoint lines .In the second part we introduce the coordinated search problem when the searcher starts looking for the target from some point a” = 0 and the target has any unsymmetric distribution. Chapter 3 In this chapter we search for a randomly moving target among a finite set of different states. A search effort is at each fixed number of time intervals is available and bounded by a random variable with a given distribution. The probability of finding the target in a certain state j at a certain time i and the detection functions are supposed to be known to the searcher. We seek for the optimal distribution of the effort (which minimizes the probability of undetection the target and searching effort ) over the set of possible different states . Here we deduce an explicit formula for the optimal distribution of the effort. Chapter 4 It contains general conclusions and recommendations for future work. Remark The second part of chapter two has been accepted in the international journal of Applied Mathematics.