İçerik dağıtımı için ayrık yer seçimi modelleri

DISCRETE LOCATION MODELS FOR CONTENT DISTRIBUTIONTolga BektaşsThe advances in information and computer technology has tremendously eased theway to reach electronic information. This, however, also brought forth many problemsregarding the distribution of electronic content. This is especially true in the Internet,where there is a phenomenal growth of demand for any kind of electronic information,placing a high burden on the underlying infrastructure. In this dissertation, we studyproblems arising in distribution of electronic content.The first problem studied here is related to Content Distribution Networks (CDNs),which have emerged as a new technology to overcome the problems arising on theInternet due to the fast growth of the web-related traffic, such as slow response timesand heavy server loads. They aim at increasing the effectiveness of the network bylocating identical or partial copies of the origin server(s) throughout the network,which are referred to as proxy servers. In order for such structures to run efficiently,the CDN must be designed such that system resource are properly managed. To thispurpose, we develop integer programming models for the problem of designing CDNsand investigate exact and heuristic algorithms for their solution.The second problem considered in this dissertation is Video Placement and Rout-ing, which is related to the so-called Video-on-Demand (VoD) services. Such servicesare used to deliver programs to the users on request and find many applications ineducation, entertainment and business. Although bearing similarities with the CDNphenomena, VoD services have special characteristics with respect to the structureof the network and the type of content distributed. We study the problem of VideoPlacement and Routing for such networks and offer an optimization based solutionalgorithm for the associated integer programming model.The third problem studied here is the problem of allocating databases in dis-tributed computing systems. In this context, we specifically focus on the well-knownmultidimensional Knapsack Problem (mKP). The mKP arises as a subproblem insolving the database location problem. We concentrate on the well known coverinequalities that are known to be important for the solution of the mKP. We thenpropose a novel separation procedure to identify violated cover inequalities and utilizethis procedure in a branch-and-cut framework devised for the solution of the mKP.1