• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 53
  • 15
  • Tagged with
  • 72
  • 72
  • 72
  • 67
  • 32
  • 30
  • 16
  • 15
  • 14
  • 14
  • 12
  • 12
  • 10
  • 10
  • 9
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A software restructuring tool for oberon

Eloff, Johannes J. 12 1900 (has links)
Thesis (MComm) -- University of Stellenbosch, 2001. / ENGLISH ABSTRACT: Software restructuring is a form of perfective maintenance that modifies the structure of a program's source code. lts goal is increased maintainability to better facilitate other maintenance activities, such as adding new functionality or correcting previously undetected errors. The modification of structure is achieved by applying transformations to the source code of a software system. Software engineers often attempt to restructure software by manually transforming the source code. This approach may lead to undesirable and undetectable changes in its behaviour. Ensuring that manual transformations preserve functionality during restructuring is difficult; guaranteeing it is almost impossible. One solution to the problem of manual restructuring is automation through use of a restructuring tool. The tool becomes responsible to examine each transformation and determine its impact on the software's behaviour. If a transformation preserves functionality, it may be applied to produce new source code. The tool only automates the application of transformations. The decision regarding which transformation to apply in a specific situation still resides with the maintainer. This thesis describes the design and implementation of a restructuring tool for the Oberon language, a successor of Pascal and Modula-2, under the PC Native Oberon operating system. The process of creating an adequate abstraction of a program's structure and its use to apply transformations and generate new source code are investigated. Transformations can be divided into different classes: Scoping, Syntactic, Control flow and Abstraction transformations. The restructuring tool described in this thesis contains implementations from all four classes. Informal arguments regarding the correctness of each transformation are also presented. / AFRIKAANSE OPSOMMING: Die herstrukturering van programmatuur is daarop gemik om die struktuur van 'n program se bronkode te wysig. Hierdie strukturele veranderings dien in die algemeen as voorbereiding vir meer omvangryke onderhoudsaktiwiteite, soos byvoorbeeld die toevoeging van nuwe funksionaliteit of die korrigering van foute wat voorheen verskuil was. Die verandering in struktuur word teweeggebring deur die toepassing van transformasies op die bronkode. Programmatuur-ontwikkelaars voer dikwels sulke transformasies met die hand uit. Sulke optrede kan problematies wees indien 'n transformasie die funksionaliteit, in terme van programgedrag, van die programmatuur beïnvloed. Dit is moeilik om te verseker dat bogenoemde metode funksionaliteit sal behou; om dit te waarborg is so te sê onmoontlik. 'n Oplossing vir bogenoemde probleem is die outomatisering van die herstruktureringsproses deur die gebruik van gespesialiseerde programmatuur. Hierdie programmatuur is in staat om die nodige transformasies toe te pas en terselfdertyd funksionaliteit te waarborg. Die keuse vir die toepassing van 'n spesifieke transformasie lê egter steeds by die programmeerder. Hierdie tesis bespreek die ontwerp en implementering van programmatuur om bronkode, geskryf in Oberon (die opvolger van Pascal en Modula-2), te herstruktureer. Die skep van 'n voldoende abstrakte voorstelling van bronkode, die gebruik van sodanige voorstelling in die toepassing van transformasies en die reprodusering van nuwe bronkode, word bespreek. Transformasies kan in vier breë klasse verdeel word: Bestek, Sintaks, Kontrolevloei en Abstraksie. Die programmatuur wat ontwikkel is vir hierdie tesis bevat voorbeelde uit elkeen van die voorafgenoemde klasse. Informele argumente word aangebied om die korrektheid van die onderskeie transformasies te staaf.
2

Random generation of finite automata over the domain of the regular languages

Raitt, Lesley Anne 12 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: The random generation of finite automata over the domain of their graph structures is a wellknown problem. However, random generation of finite automata over the domain of the regular languages has not been studied in such detail. Random generation algorithms designed for this domain would be useful for the investigation of the properties of the regular languages associated with the finite automata. We studied the existing enumerations and algorithms to randomly generate UDFAs and binary DFAs as they pertained to the domain of the regular languages. We evaluated the algorithms experimentally across the domain of the regular languages for small values of n and found the distributions non-uniform. Therefore, for UDFAs, we derived an algorithm for the random generation of UDFAs over the domain of the regular languages from Domaratzki et. al.’s [9] enumeration of the domain of the regular languages. Furthermore, for binary DFAs, we concluded that for large values of n, the bijection method is a viable means of randomly generating binary DFAs over the domain of the regular langagues. We looked at all the random generation of union-UNFAs and -UNFAs across the domain of the regular languages. Our study of these UNFAs took all possible variables for the generation of UNFAs into account. The random generation of UNFAs over the domain of the regular languages is an open problem / AFRIKAANSE OPSOMMING: Die ewekansige generasie van eindige toestand outomate (eto’s) oor die domein van hul grafiekstrukture is ’n bekende probleem. Nieteenstaande het die ewekansige generasie van eindige toestand outomate oor die domein van die regulˆere tale nie soveel aandag gekry nie. Algoritmes wat eindige toestand outomate ewekansig genereer oor die domein van die regulˆere tale sal nuttig wees om die ondersoek van die eienskappe van regulˆere tale, wat met eto’s verbind is, te bewerkstellig. Ons het die bestaande aftellings en algoritmes bestudeer vir die ewekansige generasie van deterministiese eindige toestand outomate (deto’s) met een en twee alfabetiese simbole soos dit betrekking het op die domein van die regulˆere tale bestudeer. Ons het die algoritmes eksperimenteel beoordeel oor die domein van die regulˆere tale vir outomate met min toestande en bevind dat die verspreiding nie eenvomig is nie. Daarom het ons ’n algoritme afgelei vir die ewekansige generasie van deto’s met een alfabetsimbool oor die domein van die regulˆere tale van Domaratzki et. al. [9] se aftelling. Bowendien, in die geval van deto’s met twee alfabetsimbole met ’n groot hoeveelheid toestande is die ‘bijeksie metode ’n goeie algoritme om te gebruik vir die ewekansige generasie van hierdie deto’s oor die domein van die regulˆere tale. Ons het ook die ewekansige generasie van [-nie-deterministiese eindige toestand outomate en -nie-deterministiese eindige toestand outomate oor die domein van die regulˆere tale bestudeer. Ons studie van hierdie neto’s het alle moontlike veranderlikes in ageneem. Die ewekansige generering van deto’s oor die domein van die regulˆere tale is ’n ope probleem.
3

Automated program generation : bridging the gap between model and implementation

Bezuidenhout, Johannes Abraham 02 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: The general goal of this thesis is the investigation of a technique that allows model checking to be directly integrated into the software development process, preserving the benefits of model checking while addressing some of its limitations. A technique was developed that allows a complete executable implementation to be generated from an enhanced model specification. This included the development of a program, the Generator, that completely automates the generation process. In addition, it is illustrated how structuring the specification as a transitions system formally separates the control flow from the details of manipulating data. This simplifies the verification process which is focused on checking control flow in detail. By combining this structuring approach with automated implementation generation we ensure that the verified system behaviour is preserved in the actual implementation. An additional benefit is that data manipulation, which is generally not suited to model checking, is restricted to separate, independent code fragments that can be verified using verification techniques for sequential programs. These data manipulation code segments can also be optimised for the implementation without affecting the verification of the control structure. This technique was used to develop a reactive system, an FTP server, and this experiment illustrated that efficient code can be automatically generated while preserving the benefits of model checking. / AFRIKAANSE OPSOMMING: Hierdie tesis ondersoek ’n tegniek wat modeltoetsing laat deel uitmaak van die sagtewareontwikkelingsproses, en sodoende betroubaarheid verbeter terwyl sekere tekorkominge van die tradisionele modeltoetsing proses aangespreek word. Die tegniek wat ontwikkel is maak dit moontlik om ’n volledige uitvoerbare implementasie vanaf ’n gespesialiseerde model spesifikasie te genereer. Om die implementasie-generasie stap ten volle te outomatiseer is ’n program, die Generator, ontwikkel. Daarby word dit ook gewys hoe die kontrolevloei op ’n formele manier geskei kan word van data-manipulasie deur gebruik te maak van ’n staatoorgangsstelsel struktureringsbenadering. Dit vereenvoudig die verifikasie proses, wat fokus op kontrolevloei. Deur di´e struktureringsbenadering te kombineer met outomatiese implementasie-generasie, word verseker dat die geverifieerde stelsel se gedrag behou word in die finale implementasie. ’n Bykomende voordeel is dat data-manipulasie, wat gewoonlik nie geskik is vir modeltoetsing nie, beperk word tot aparte, onafhanklike kode segmente wat geverifieer kan word deur gebruik te maak van verifikasie tegnieke vir sekwensi¨eele programme. Hierdie data-manipulasie kode segmente kan ook geoptimeer word vir die implementasie sonder om die verifikasie van die kontrole struktuur te be¨ınvloed. Hierdie tegniek word gebruik om ’n reaktiewe stelsel, ’n FTP bediener, te ontwikkel, en di´e eksperiment wys dat doeltreffende kode outomaties gegenereer kan word terwyl die voordele van modeltoetsing behou word.
4

Minimization of symmetric difference finite automata

Muller, Graham 03 1900 (has links)
Thesis (MSc (Computer Science))--University of Stellenbosch, 2006. / The minimization of a Finite Automaton (FA) deals with the construction of an equivalent FA with the least number of states. Traditional FAs and the minimization thereof is a well defined and researched topic within academic literature. Recently a generalized form of the FA, namely the generalized FA(*-FA), has been derived from these traditional FAs. This thesis investigates the minimization and reduction of one case of ...
5

Inductive machine learning bias in knowledge-based neurocomputing

Snyders, Sean 04 1900 (has links)
Thesis (MSc) -- Stellenbosch University , 2003. / ENGLISH ABSTRACT: The integration of symbolic knowledge with artificial neural networks is becoming an increasingly popular paradigm for solving real-world problems. This paradigm named knowledge-based neurocomputing, provides means for using prior knowledge to determine the network architecture, to program a subset of weights to induce a learning bias which guides network training, and to extract refined knowledge from trained neural networks. The role of neural networks then becomes that of knowledge refinement. It thus provides a methodology for dealing with uncertainty in the initial domain theory. In this thesis, we address several advantages of this paradigm and propose a solution for the open question of determining the strength of this learning, or inductive, bias. We develop a heuristic for determining the strength of the inductive bias that takes the network architecture, the prior knowledge, the learning method, and the training data into consideration. We apply this heuristic to well-known synthetic problems as well as published difficult real-world problems in the domain of molecular biology and medical diagnoses. We found that, not only do the networks trained with this adaptive inductive bias show superior performance over networks trained with the standard method of determining the strength of the inductive bias, but that the extracted refined knowledge from these trained networks deliver more concise and accurate domain theories. / AFRIKAANSE OPSOMMING: Die integrasie van simboliese kennis met kunsmatige neurale netwerke word 'n toenemende gewilde paradigma om reelewereldse probleme op te los. Hierdie paradigma genoem, kennis-gebaseerde neurokomputasie, verskaf die vermoe om vooraf kennis te gebruik om die netwerkargitektuur te bepaal, om a subversameling van gewigte te programeer om 'n leersydigheid te induseer wat netwerkopleiding lei, en om verfynde kennis van geleerde netwerke te kan ontsluit. Die rol van neurale netwerke word dan die van kennisverfyning. Dit verskaf dus 'n metodologie vir die behandeling van onsekerheid in die aanvangsdomeinteorie. In hierdie tesis adresseer ons verskeie voordele wat bevat is in hierdie paradigma en stel ons 'n oplossing voor vir die oop vraag om die gewig van hierdie leer-, of induktiewe sydigheid te bepaal. Ons ontwikkel 'n heuristiek vir die bepaling van die induktiewe sydigheid wat die netwerkargitektuur, die aanvangskennis, die leermetode, en die data vir die leer proses in ag neem. Ons pas hierdie heuristiek toe op bekende sintetiese probleme so weI as op gepubliseerde moeilike reelewereldse probleme in die gebied van molekulere biologie en mediese diagnostiek. Ons bevind dat, nie alleenlik vertoon die netwerke wat geleer is met die adaptiewe induktiewe sydigheid superieure verrigting bo die netwerke wat geleer is met die standaardmetode om die gewig van die induktiewe sydigheid te bepaal nie, maar ook dat die verfynde kennis wat ontsluit is uit hierdie geleerde netwerke meer bondige en akkurate domeinteorie lewer.
6

A language to support verification of embedded software

Swart, Riaan 04 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Embedded computer systems form part of larger systems such as aircraft or chemical processing facilities. Although testing and debugging of such systems are difficult, reliability is often essential. Development of embedded software can be simplified by an environment that limits opportunities for making errors and provides facilities for detection of errors. We implemented a language and compiler that can serve as basis for such an experimental environment. Both are designed to make verification of implementations feasible. Correctness and safety were given highest priority, but without sacrificing efficiency wherever possible. The language is concurrent and includes measures for protecting the address spaces of concurrently running processes. This eliminates the need for expensive run-time memory protection and will benefit resource-strapped embedded systems. The target hardware is assumed to provide no special support for concurrency. The language is designed to be small, simple and intuitive, and to promote compile-time detection of errors. Facilities for abstraction, such as modules and abstract data types support implementation and testing of bigger systems. We have opted for model checking as verification technique, so our implementation language is similar in design to a modelling language for a widely used model checker. Because of this, the implementation code can be used as input for a model checker. However, since the compiler can still contain errors, there might be discrepancies between the implementation code written in our language and the executable code produced by the compiler. Therefore we are attempting to make verification of executable code feasible. To achieve this, our compiler generates code in a special format, comprising a transition system of uninterruptible actions. The actions limit the scheduling points present in processes and reduce the different interleavings of process code possible in a concurrent system. Requirements that conventional hardware places on this form of code are discussed, as well as how the format influences efficiency and responsiveness. / AFRIKAANSE OPSOMMING: Ingebedde rekenaarstelsels maak deel uit van groter stelsels soos vliegtuie of chemiese prosesseerfasiliteite. Hoewel toetsing en ontfouting van sulke stelsels moeilik is, is betroubaarheid dikwels onontbeerlik. Ontwikkeling van ingebedde sagteware kan makliker gemaak word met 'n ontwikkelingsomgewing wat geleenthede vir foutmaak beperk en fasiliteite vir foutbespeuring verskaf. Ons het 'n programmeertaal en vertaler geïmplementeer wat as basis kan dien vir so 'n eksperimentele omgewing. Beide is ontwerp om verifikasie van implementasies haalbaar te maak. Korrektheid en veiligheid het die hoogste prioriteit geniet, maar sonder om effektiwiteit prys te gee, waar moontlik. Die taal is gelyklopend en bevat maatreëls om die adresruimtes van gelyklopende prosesse te beskerm. Dit maak duur looptyd-geheuebeskerming onnodig, tot voordeel van ingebedde stelsels met 'n tekort aan hulpbronne. Daar word aangeneem dat die teikenhardeware geen spesiale ondersteuning vir gelyklopendheid bevat nie. Die programmeertaal is ontwerp om klein, eenvoudig en intuïtief te wees, en om vertaaltyd-opsporing van foute te bevorder. Fasiliteite vir abstraksie, byvoorbeeld modules en abstrakte datatipes, ondersteun implementering en toetsing van groter stelsels. Ons het modeltoetsing as verifikasietegniek gekies, dus is die ontwerp van ons programmeertaal soortgelyk aan dié van 'n modelleertaal vir 'n modeltoetser wat algemeen gebruik word. As gevolg hiervan kan die implementasiekode as toevoer vir 'n modeltoetser gebruik word. Omdat die vertaler egter steeds foute kan bevat, mag daar teenstrydighede bestaan tussen die implementasie geskryf in ons implementasietaal, en die uitvoerbare masjienkode wat deur die vertaler gelewer word. Daarom poog ons om verifikasie van die uitvoerbare masjienkode haalbaar te maak. Om hierdie doelwit te bereik, is ons vertaler ontwerp om 'n spesiale formaat masjienkode te genereer bestaande uit 'n oorgangstelsel wat ononderbreekbare (atomiese) aksies bevat. Die aksies beperk die skeduleerpunte in prosesse en verminder sodoende die aantal interpaginasies van proseskode wat moontlik is in 'n gelyklopende stelsel. Die vereistes wat konvensionele hardeware aan dié spesifieke formaat kode stel, word bespreek, asook hoe die formaat effektiwiteit en reageerbaarheid van die stelsel beïnvloed.
7

Ontology comprehension

Bergh, Johann Rath 03 1900 (has links)
Thesis (MSc (Mathematical Sciences. Computer Science))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Ontologies are conceptual models of a domain of discourse and are used in a number of applications to model a field of knowledge. For example, SNOMED, an ontology of medical terminology, is widely used among medical professionals. Commercial ontologies, such as SNOMED, can have hundreds of thousands of concepts. People who want to use these ontologies need an understanding thereof, but the sheer magnitude of these ontologies hampers comprehension. It was within this context that the need arose for software tools that facilitate the understanding of ontologies. Given this background, our aim is to investigate a new area within the field of ontologies, namely, ontology comprehension. We make a contribution to it by developing an ontology comprehension framework and writing a software tool of our own. This software tool, PathViz, helps users to understand how different concepts in an ontology are related to each other and what effect entailments have on the way concepts in an ontology relate to each other. The ontology comprehension framework, PathViz and the reasoning measurement instruments were found useful for ontology comprehension by participants at an ontology workshop. / AFRIKAANSE OPSOMMING: Ontologieë is konseptuele modelle van ’n domein en word in verskeie toepassings gebruik om ’n kennisveld te modelleer. SNOMED is ’n voorbeeld van ’n ontologie van mediese terme wat baie gebruik word deur die mediese beroepslui. Kommersiële ontologieë, soos SNOMED, kan bestaan uit duisende konsepte. Dit is belangrik om hierdie ontologieë wat gebruik word te verstaan, maar die enorme omvang van hierdie ontologieë belemmer die verstaanproses. In hierdie konteks het die behoefte ontstaan vir programmatuur wat die verstaanproses van ontologieë vergemaklik. Met hierdie agtergrond inaggenome, is dit ons doel om ’n nuwe area in die veld van ontologieë te ondersoek, naamlik, Ontologie-begrip. Ons maak ’n bydra tot hierdie veld deur ’n raamwerk vir ontologie-begrip te ontwikkel en programmatuur van ons eie te skryf. Hierdie programmatuur, PathViz, help gebruikers om te verstaan hoe verskillende konsepte in ’n ontologie aan mekaar verwant is. Verder help dit gebruikers om te verstaan watter invloed afleidings uit die ontologieë het op konsepverwantskappe. Deelnemers aan ’n ontologie-werkswinkel het gevind dat die raamwerk vir ontologie-begrip, PathViz en die instrumente wat die invloed van die ontologie-redeneerder meet, ontologie-begrip bevorder.
8

Implementation of cell clustering in cellular automata

Adams, Roxane 03 1900 (has links)
Thesis (MSc (Mathematical Sciences)) University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Cellular Automata (CA) have become a popular vehicle to study complex dynamical behaviour of systems. CA can be used to model a wide variety of physical, biological, chemical and other systems. Such systems typically consist of subparts that change their state independently, based on the state of their immediate surroundings and some generally shared laws of change. When the CA approach was used to solve the LEGO construction problem, the best solution was found when using a variant of CA allowing for the clustering of cells. The LEGO construction problem concerns the optimal layout of a set of LEGO bricks. The advantages found for using the CA method with clustering in this case are the ease of implementation, the significantly smaller memory usage to previously implemented methods, and its trivial extension to construct multicoloured LEGO sculptures which were previously too complex to construct. In our research we propose to explore the definitions of clustering in CA and investigate the implementation and application of this method. We look at the ant sorting method described by Lumer and Faieta, and compare the implementation of this algorithm using regular CA as well as the clustering variation. The ant sorting model is a simple model, in which ants move randomly in space and pick up and deposit objects on the basis of local information. / AFRIKAANSE OPSOMMING: Sellulêre Outomate (SO) het ’n populêre metode geword om die komplekse dinamiese gedrag van sisteme bestudeer. SO kan gebruik word om ’n groot verskeidenheid fisiese, biologiese, chemiese en ander tipe sisteme te modelleer. Sulke sisteme bestaan tipies uit subafdelings wat, gebaseer op die status van hulle omgewing en ’n paar algemene gedeelde reëls van verandering, hulle status onafhanklik verander. Met die gebruik van die SO benadering om the LEGO konstruksieprobleem op te los, is die beste oplossing bereik deur gebruik te maak van ’n variant van SO, waar selle saamgroepeer kan word. Die LEGO konstruksieprobleem behels die optimale uitleg van ’n stel LEGO blokkies. In hierdie geval is die voordele van die SO met sel groepering die maklike implementasie, ’n beduidende kleiner geheuegebruik teenoor voorheen geïmplementeerde metodes, en die triviale uitbreiding daarvan om gekleurde LEGO beelde wat voorheen te kompleks was, te kan bou. In ons ondersoek verken ons die definisies van selgroepering in SO en ondersoek die implementasie en toepassing van die metode. Ons kyk na die miersorteringsmetode beskryf deur Lumer en Faieta, en vergelyk die implementasie van hierdie algoritme deur gewone SO asook die groeperingsvariasie te gebruik. Die miersorteringsmodel is ’n eenvoudige model waarin miere lukraak in ’n omgewing beweeg en voorwerpe optel of neersit volgens plaaslike inligting.
9

Computer-controlled human body coordination

Hakl, Henry 12 1900 (has links)
Thesis (MSc) -- University of Stellenbosch, 2003. / ENGLISH ABSTRACT: A need for intelligent robotic machines is identified. Research and experiments have focussed on stable, or relatively stable, dynamic simulated systems to demonstrate the feasibility of embedding advanced AI into dynamic physical systems. This thesis presents an attempt to scale the techniques to a dynamically highly unstable system - the coordination of movements in a humanoid model. Environmental simulation, articulated systems and artificial intelligence methods are identified as three essential layers for a complete and unified approach to embedding AI into robotic machinery. The history of the physics subsystem for this project is discussed, leading to the adoption of the Open Dynamics Engine as the physics simulator of choice. An approach to articulated systems is presented along with the EBNF of a hierarchical articulated system that was used to describe the model. A revised form of evolution is presented and justified. An AI model that makes use of this new evolutionary paradigm is introduced. A variety of AI variants are defined and simulated. The results of these simulations are presented and analysed. Based on these results recommendations for future work are made. / AFRIKAANSE OPSOMMING: Die beheer van dinamiese masjiene, soos intelligente robotte, is tans beperk tot fisies stabilie - of relatief stabiele - sisteme. In hierdie tesis word die tegnieke van kunsmatige intelligensie (KI) toegepas op die kontrole en beheer van 'n dinamies hoogs onstabiele sisteem: 'n Humanoïede model. Fisiese simulasie, geartikuleerde sisteme en kunmatige intelligensie metodes word geïdentifiseer as drie noodsaaklike vereistes vir 'n volledige en eenvormige benadering tot KI beheer in robotte. Die implementasie van 'n fisiese simulator word beskryf, en 'n motivering vir die gebruik van die sogenaamde "Open Dynamics Engine" as fisiese simulator word gegee. 'n Benadering tot geartikuleerde sisteme word beskryf, tesame met die EBNF van 'n hierargiese geartikuleerde sisteem wat gebruik is om die model te beskryf. 'n Nuwe interpretasie vir evolusie word voorgestel, wat die basis vorm van 'n KI model wat in die tesis gebruik word. 'n Verskeidenheid van KI variasies word gedefineer en gesimuleer, en die resultate word beskryf en ontleed. Voorstelle vir verdere navorsing word gemaak.
10

A bandwidth market for traffic engineering in telecommunication networks

Combrink, J. J. (Jacobus Johannes) 04 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Traffic engineering determines the bandwidth allocation required to meet the traffic loads in a network. Similarly an economic market determines the resource allocation required to meet the demand for resources. The term bandwidth market denotes traffic engineering methods that use economic market methodology to determine the bandwidth allocation required to meet the traffic loads. A bandwidth market is an attractive traffic engineering method because of its distributed nature and ability to respond quickly to changes in network architecture or traffic loads. Network terminology is frequently used to define bandwidth markets. Our approach is to use the concepts of microeconomics to define a bandwidth market. The result is that our bandwidth markets are similar to economic markets, which is advantageous for applying economic principles correctly. This thesis presents the theoretical basis for two bandwidth markets. The first bandwidth market is a framework for building bandwidth markets. The second bandwidth market represents a society of cooperating individuals. The society distributes resources via a mechanism based on economic principles. An implementation of the bandwidth market is presented in the form of an optimisation algorithm, followed by its application to several test networks. We show that, in the test networks examined, the optimisation algorithm reduces the network loss. For all test networks, the network loss achieved by the optimisation algorithm compares well with the network loss achieved by a centralised optimisation algorithm. / AFRIKAANSE OPSOMMING: Verkeersingenieurswese bepaal die nodige bandwydtetoekenning om die verkeersvolume in 'n netwerk te dra. Op 'n soortgelyke wyse bepaal 'n ekonomiese mark die nodige hulpbrontoekenning om die aanvraag vir hulpbronne te bevredig. Die terme bandwydtemark stel verkeersingenieurswesetegnieke voor wat ekonomiese-mark metodes gebruik om die bandwydtetoekenning vir die verkeersvolume in 'n netwerk te bepaal. 'n Bandwydtemark is 'n aantreklike verkeersingenieurswesetegniek omdat dit verspreid van aard is en vinnig kan reageer op veranderinge in netwerk argitektuur en verkeersvolume. Netwerkterminologie word gereeld gebruik om bandwydtemarkte te definieer. Ons benadering is om mikro-ekonomiese begrippe te gebruik om 'n bandwydtemark te definieer. Die resultaat is dat ons bandwydtemarkte soortgelyk aan ekonomiese markte is, wat voordelig is vir die korrekte toepassing van ekonomiese beginsels. Hierdie tesis lê die teoretiese grondwerk vir twee bandwydtemarkte. Die eerste bandwydtemark is 'n raamwerk vir die ontwikkeling van bandwydtemarkte. Die tweede bandwydtemark stel 'n vereniging van samewerkende individue voor. Die vereniging versprei bandwydte deur middel van 'n meganisme wat gebasseer is op ekonomiese beginsels. 'n Implementasie van hierdie bandwydtemark word voorgestel in die vorm van 'n optimeringsalgoritme, gevolg deur die toepassing van die optimeringsalgoritme op 'n aantal toetsnetwerke. Ons wys dat die bandwydtemark die netwerkverlies verminder in die toetsnetwerke. In terme van netwerkverlies vaar die bandwydtemark goed vergeleke met 'n gesentraliseerde optimeringsalgoritme.

Page generated in 0.1696 seconds