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Archived Theses
Mobil internet protokolü versiyon 4'de yönlendirme optimizasyonlu ve optimizasyonsuz performans analizi
ABSTRACT Performance Analysis of Mobile IPv4 With and Without Route Optimization Altay, Serap Ms, Department of Computer Engineering Supervisor: Asst. Prof. Gülsün Töreci May 2003, 92 pages The support of mobility in the modern communications network is becoming essential and important with the development of mobile devices. Mobile Internet Protocol is built on IPv4. Mobile IP has been proposed by IETF (Internet Engineering Task Force) to support portable IP addresses on Internet. In the basic Mobile IP protocol, datagrams destined for the mobile node are sent from wired or wireless hosts. These datagrams have to travel through the home agent when mobile node is away from home. On the other hand, the datagrams sent from mobile hosts to wired host can be sent directly. This asymmetric routing, called "Triangle Routing". On the other hand, when the destination node is very close to mobile host, this creates a problem. Solving of the problem "Triangle Routing" is one appealing topic in mobile IP. IETF proposed extension part of the basic mobile IP, called "Route Optimization" to address this problem. IPv4 has already been widely deployed. Moreover, it will most probably dominate the Internet for a long time. Therefore, in this thesis implemented mobile IPv4 with and without route optimization in OMNeT++. Simulations have already been done to justify the modification. Keywords: Mobile IP, mobile communication, route optimization, triangle routing. iii
Adi diferensiyel denklemlerin nümerik çözümleri
Since ordinary differential equations are useful in modelling the behavior of many physical processes, methods of solution for these equations are of great importance to engineers and scientists. Even though well-known ana lytical techniques can solve many important differential equations, a greater number of physically significant differential equations can not be solved using these techniques. Fortunately, the solutions of these equations can usually be generated numerically. There are many methods for finding approximate solutions to differential equations. Throughout the thesis, numerical techniques for ordinary differen tial equations are considered. In the first chapter, basic concepts which are going to be used are given. Second chapter contains numerical methods, all of which do not generate exact solutions, only approximate ones. Finally, in the last chapter a new numerical integration technique inspired by the Runge- Kutta method to solve the initial value problem is given. The method pre sented adds higher order derivative terms to the Runge-Kutta stage equations resulting in a higher order method without increasing the number of stages. Keywords: Ordinary Differential Equations, Numerical Analysis, Runge-Kutta Method. IV
Matematiksel yöntemleriyle süperintegrallenebilir sistemler
Polynomial invariants and the geometric aspects of superintegrable systems in two- dimensional space were analyzed. Killing tensors and Killing- Yano tensors corre sponding to a set of four two dimensional superintegrable systems were found. The geometries obtained by adding a suitable term involving the components of the angu lar momentum to the corresponding free Lagrangians. Killing vectors, Killing- Yano and Killing tensors of the obtained manifolds were investigated. Keywords: Superintegrable systems, polynomial invariants, Killing tensors, Killing- Yano tensors. m
Semiosis of resort interiors
This study attempts to construct a methodology, originating from semiotic knowledge that enables to analyse the communication between the developers of tourism places and their users. It questions the legibility of intended meanings in the design of contemporary rising trends of touristic spaces by their receiver; the tourist. The choice of the subject is influenced from the rapid proliferation of themed resort hotel, which is taken as a complex of architectural objects -considering it as 'interior space' from the limits of its outer boundary and presupposed as a 'precoded system'. This statement expresses existence of two distinctive parts: the 'encoder' as designer and the 'decoder' as the tourist. This study probes to define variable characteristics of the precoded system to manifest the representations of meaning in architectural object. A particular emphasis is given to reproduction in the context of tourism. An interactive analysis of a case, the 'Topkapi Palace Resort Hotel', by conduct interviews with encoders, and informal interviews with decoders is to identify the intentions of the designer and meaning of the designed space -medium of these intentions- for the tourist. Indeed, the object of the study is to investigate how the precoded system is encoded. Moreover, the concentration is on the analysis of the 'decoder', the tourist, the authenticity of her/his experiences with the touristic space, to find out how the encoded system is decoded.Keywords: themed resort hotel, meaning, tourist experience, authenticity, Topkapi Palace.
Fractional differential equations and their applications
The Laplace transform method for solving fractional differential equations is pre sented. The fractional diffusion and fractional Schrödinger equations together with their properties are investigated. The Lagrangians linear in velocities are analyzed using the fractional calculus, and the fractional Euler-Lagrange equations are derived. Keywords: Fractional derivative, fractional integral, fractional diffusion equation, frac tional Schrödinger equation, fractional Euler-Lagrange equations. Ill
Architecture of new generation networks
Architecture of New Generation Networks Arpali, Çağlar Ms, Department of Computer Engineering Supervisor: Asst. Prof. Dr. Halil T. Eyyuboğlu June 2004, 64 pages In this thesis, two macro cell propagation models for network architecture of Universal Mobile Communication System (UMTS), namely, UMTS vehicular ITU-R model [1] and extended Okumura Hata model [2] are compared using digital map and field measured data collected from a particular site in Ankara, Turkey. Comparison is made on the basis of different environment of vegetations, terrains, buildings types and morphology structures. To overcome the inadequacy of the second propagation model, we have proposed different topography and morphology corrections. For this purpose, sample calculations are performed for path lengths of 2700 m while the general results are plotted for a range of 6000 m. We have also investigated radio network planning with related link budgets for comparing the cell ranges of both models according to the difference service type of 12.2 kbps voice and 384 kbps real-time data. Our findings indicate that in the determination of signal path loss, average buildings height {Amr) is more decisive than others in UMTS vehicular ITU-R model, whereas for extended Okumura Hata model, topographic structure of the terrain (Q) and effective antenna height (heff) are most dominant factors and UMTS vehicular ITU-R model predicts shorter cell ranges with respect to extended Okumura model. Key Words: UMTS, Propagation, Signal Path Loss, Radio Network Planning İ
A computational analysis of a language structure in natural language text processing
A COMPUTATIONAL ANALYSIS OFA LANGUAGE STRUCTURE INNATURAL LANGUAGE TEXT PROCESSINGS NAN EŞText categorization or classification is a general task of classifying un-organizednatural language texts according to specific subject matter or category. Electronic mail(e-mail) filtering is a binary text classification problem which the user emails can beclassified as legitimate (non-spam) or un-wanted mail (spam).In this study, we tried to find a filtering solution that is able to automaticallyclassify emails into spam and legitimate categories. In order to automatically andefficiently classify emails as spam or legitimate we took advantage of some MachineLearning methods and some novel ideas from Information Retrieval.
Evaluation of terrain rendering algorithms
ABSTRACTEVALUATION OF TERRAIN RENDERING ALGORITHMSİnam, EminTerrain rendering plays an important role in outdoor virtual reality applications,games, Geographic Information System (GIS), military mission planning?s and flightsimulations, etc. Many of these applications require real-time dynamic interactionfrom end users and thus are required to rapidly process terrain data to adapt to userinput. Typical height fields consist of a large number of polygons, so that even mosthigh performance graphics computers have great difficulties to display evenmoderately sized height fields at interactive frame rates. The common solution is toreduce the complexity of the scene while maintaining a high image quality. Thisthesis is an evaluation of three real-time continuous terrain levels of detail algorithmsdescribed in the papers ROAMing Terrain: Real-time Optimally Adapting Meshes byDuchaineau, Real-Time Generation of Continuous Levels of Detail for Height Fieldsby Röttger and Fast Terrain Rendering Using Geometrical MipMapping by WillemH. de Boer. The evaluation and comparison of the algorithms is based on the trade-off of polygon count to terrain accuracy over separate test data sets. The main aim ofthis thesis is research on terrain rendering algorithms that is generate high qualityimage in real-time with using height data.
The snakeboard as a mechanical control and constrained system
ABSTRACTTHE SNAKEBOARD AS A MECHANICAL CONTROL AND CONSTRAINEDSYSTEMBilgen, AdnanThe snakeboard problem is investigated as a constrained, control system usingthe Hamilton-Jacobi formulation. Equations of motion are solved numerically in La-grangian and Hamiltonian approaches.
An application of the vehicle routing problem to a glass manufacturing firm
ABSTRACTAN APPLICATION OF THE VEHICLE ROUTING PROBLEM TO A GLASSMANUFACTURING FIRMSeyran, İpekThis thesis presents an exact algorithm and a heuristic method for the delivery and transportation of glassplates for a glass manufacturing firm. A variant of the Capacitated Vehicle Routing Problem (CVRP) isproposed as a first attempt to solve the problem which minimizes total traveling of all the vehicles. Sincethe CVRP is known to be NP-hard, the solution method cannot obtain a solution to the model. Therefore anexact algorithm which is a kind of set-covering-based algorithm is proposed next. The CVRP is modeled asa set covering (SC) problem. Then column generation (CG) method is applied to the linear relaxation of theSC problem. The branch-and-price algorithm is utilized in finding an integer solution on the solution of theCG procedure. Numerical experimentations reveals that exact algorithm is slower, and fails finding asolution to larger size problems. Consequently a heuristic is developed as a generalization of petalalgorithm. Initialization of this algorithm requires using some Traveling Salesman Problem (TSP)construction heuristics for finding a TSP tour, and a TSP improvement heuristic further improves the TSPtour. Then Petal Algorithm is applied to find all of the feasible petal routes to the TSP tour obtained. SPmodel helps the petal routes to find the best VRP routes. When the best VRP route is found, a VRPimprovement heuristic attempts improving the VRP route. Finally, the number of delivery vehicles requiredand the vehicle routes are determined for the glass manufacturing firm.