Thesis (M. App. Sc.)--Carleton University, 2004. / Includes bibliographical references (p. 80-83). Also available in electronic format on the Internet.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 138-145). Also available via the Internet.

Orientador: Fernando Jose Von Zuben / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-11T02:37:26Z (GMT). No. of bitstreams: 1 Pinto_JoseCarlosLima_M.pdf: 2121571 bytes, checksum: 9c655f127eb2b45c71b750509a43c3a1 (MD5) Previous issue date: 2006 / Resumo: Essa dissertação apresenta um algoritmo de detecção de falhas composto de múltiplos módulos interconectados e operando de acordo com o paradigma suportado pela Teoria do Perigo em imunologia. Esse algoritmo busca atingir características significativas que um sistema de detecção de falhas deve expressar ao monitorar um sistema telefônico. Essas características seriam basicamente a adaptabilidade, devido à forte variação que esse sistema pode ter em seus parâmetros ao longo do tempo, e a diminuição no número de falsos positivos que podem ser gerados ao se classificar como falha toda anormalidade encontrada. Cenários simulados foram concebidos para validar a proposta, sendo que os resultados obtidos foram analisados e comparados com propostas alternativas / Abstract: Abstract This thesis presents a fault detection algorithm composed of multiple interconnected modules, and operating according to the paradigm supported by the Danger Theory in immunology. This algorithm attempts to achieve significant features that a fault detection system is supposed to express when monitoring a telephone system. These features would basically be adaptability, due to the strong variation that operational conditions may exhibit over time, and the decrease in the number of false positives, which can be generated when any abnormal behavior is erroneously classified as being a fault. Simulated scenarios have been conceived to validate the proposal, and the obtained results are then analyzed and compared with alternative proposals / Mestrado / Engenharia de Computação / Mestre em Engenharia Elétrica

Orientador: Laymert Garcia dos Santos / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciencias Humanas / Made available in DSpace on 2018-08-11T11:06:01Z (GMT). No. of bitstreams: 1 Vicentin_DiegoJair_M.pdf: 1185617 bytes, checksum: cbf4ac102a02985e7940032f6dbbb1b7 (MD5) Previous issue date: 2008 / Resumo: A dissertação de mestrado que ora se apresenta pretende tratar do consumo de um objeto técnico que penetrou de maneira tão incisiva na vida dos homens contemporâneos que, em pouco tempo, tê-lo consigo tornou-se praticamente inescapável. Trata-se do aparelho de telefone celular. Para examinar o consumo deste gadget, seguimos em duas frentes de investigação. Na primeira, decidimos verificar a maneira como se constrói uma de suas qualidades mais festejadas: a mobilidade. Nessa investigação, partimos do enlace entre as tecnicidades do aparelho e as expectativas que nutre. Ou seja, tanto as prerrogativas técnicas do aparelho e da rede em que se insere, quanto as significações que carrega e as expectativas que gera a partir de seu funcionamento ideal (ou idealizado), servem de base para pautarmos os limites e possibilidades daquilo a que nomeamos como mobilidade celular. A segunda frente de pesquisa refere-se diretamente à concepção de consumo. Fizemos uma breve (e necessariamente incompleta) revisão sobre o tema que perpassa três diferentes perspectivas teóricas e sugere a existência de um trajeto que parte do ¿mundo da natureza¿ em direção à subjetividade humana, passando pelas lutas simbólicas por poder e distinção. Esse exercício nos levou a uma noção de consumo operatória na subseqüente abordagem do aparelho celular. Resulta, no capítulo final, uma discussão acerca do modo como se consome a mobilidade celular. Explorando algumas das transformações que a relação de consumo opera tanto em sujeito quanto em objeto, e as motivações que ensejam tal relação, inclusive, percorrendo zonas de sombra entre produção e consumo / Abstract: This present work intends to analyze the consumption of a technological object that got so deeply embedded in the contemporary way of life that, in little time, not having it became almost impossible; this object is the cellular phone. To examine the consumption of this gadget, we've followed two investigation fronts. In the first one, we decided to study the way its most praised quality is constructed: the mobility. In this investigation, we built upon the entwinement of the object's technological aspects and the expectations nourished by it. So, the technological prerogatives of the gadget and the network in which it works, along with the meanings carried by it and the expectations brought by its ideal (or idealized) functioning served as a base to set the limits and possibilities of what we called cellphone mobility. The second front of this research deals directly with the conception of consumption. We made a brief (and necessarily incomplete) review about the subject that intertwines three different theoretical perspectives, and suggests the existence of a path that goes from the "world of nature" to the human subjectivity, passing by the symbolical struggles for power and distinction. This exercise took us to a notion of consumption that was operational in the following approach of the cellular phone. And in the final chapter we arrive at a discussion about the way the cellphone mobility is consumed, exploring some of the changes that this consumption relationship works in the agent and also in the object, and the motivations that foster this relationship, passing also by gray zones between production and consumption / Mestrado / Mestre em Sociologia

Please read the abstract in the section 00front of this document / Dissertation (M Eng (Electronic Engineering))--University of Pretoria, 2005. / Electrical, Electronic and Computer Engineering / unrestricted

Please read the abstract in the section 00front of this document / Dissertation (M Eng (Electronic Engineering))--University of Pretoria, 2006. / Electrical, Electronic and Computer Engineering / unrestricted

Thesis (MSc)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: Cellular network operators globally loose between 3% and 5% of their annual revenue to telecommunications fraud. Hence it is of great importance that fraud management systems are implemented to detect, alarm, and shut down fraud within minutes, minimising revenue loss. Modern proprietary fraud management systems employ (i) classification methods, most often artificial neural networks learning from classified call data records to classify new call data records as fraudulent or legitimate, (ii) statistical methods building subscriber behaviour profiles based on the subscriber’s usage in the cellular network and detecting sudden changes in behaviour, and (iii) rules and threshold values defined by fraud analysts, utilising their knowledge of valid fraud cases and the false alarm rate as guidance. The purpose of this thesis is to establish a context for and evaluate the performance of well-known data mining techniques that may be incorporated in the fraud detection process. Firstly, a theoretical background of various well-known data mining techniques is provided and a number of seminal articles on fraud detection, which influenced this thesis, are summarised. The cellular telecommunications industry is introduced, including a brief discussion of the types of fraud experienced by South African cellular network operators. Secondly, the data collection process and the characteristics of the collected data are discussed. Different data mining techniques are applied to the collected data, demonstrating how user behaviour profiles may be built and how fraud may be predicted. An appraisal of the performances and appropriateness of the different data mining techniques is given in the context of the fraud detection process. Finally, an indication of further work is provided in the conclusion to this thesis, in the form of a number of recommendations for possible adaptations of the fraud detection methods, and improvements thereof. A combination of data mining techniques that may be used to build a comprehensive fraud detection model is also suggested. / AFRIKAANSE OPSOMMING: Sellulêre netwerk operateurs verloor wêreldwyd tussen 3% en 5% van hul jaarlikse inkomste as gevolg van telekommunikasie bedrog. Dit is dus van die uiterse belang dat bedrog bestuurstelsels geïmplimenteer word om bedrog op te spoor, alarms te genereer, en bedrog binne minute te staak om verlies aan inkomste tot ’n minimum te beperk. Moderne gepatenteerde bedrog bestuurstelsels maak gebruik van (i) klassifikasie metodes, mees dikwels kunsmatige neurale netwerke wat leer vanaf geklassifiseerde oproep rekords en gebruik word om nuwe oproep rekords as bedrog-draend of nie bedrog-draend te klassifiseer, (ii) statistiese metodes wat gedragsprofiele van ’n intekenaar bou, gebaseer op die intekenaar se gedrag in die sellulêre netwerk, en skielike verandering in gedrag opspoor, en (iii) reëls en drempelwaardes wat deur bedrog analiste daar gestel word, deur gebruik te maak van hulle ondervinding met geldige gevalle van bedrog en die koers waarteen vals alarms gegenereer word. Die doel van hierdie tesis is om ’n konteks te bepaal vir en die werksverrigting te evalueer van bekende data ontginningstegnieke wat in bedrog opsporingstelsels gebruik kan word. Eerstens word ’n teoretiese agtergrond vir ’n aantal bekende data ontginningstegnieke voorsien en ’n aantal gedagteryke artikels wat oor bedrog opsporing handel en wat hierdie tesis beïnvloed het, opgesom. Die sellulêre telekommunikasie industrie word bekend gestel, insluitend ’n kort bespreking oor die tipes bedrog wat deur Suid-Afrikaanse sellulˆere telekommunikasie netwerk operateurs ondervind word. Tweedens word die data versamelingsproses en die eienskappe van die versamelde data bespreek. Verskillende data ontginningstegnieke word vervolgens toegepas op die versamelde data om te demonstreer hoe gedragsprofiele van gebruikers gebou kan word en hoe bedrog voorspel kan word. Die werksverrigting en gepastheid van die verskillende data ontginningstegnieke word bespreek in die konteks van die bedrog opsporingsproses. Laastens word ’n aanduiding van verdere werk in die gevolgtrekking tot hierdie tesis verskaf, en wel in die vorm van ’n aantal aanbevelings oor moontlike aanpassings en verbeterings van die bedrog opsporingsmetodes wat beskou en toegepas is. ’n Omvattende bedrog opsporingsmodel wat gebruik maak van ’n kombinasie van data ontginningstegnieke word ook voorgestel.

Thesis (MBA (Business Management))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The mobile phone has not only changed the way the world works today, but also changed the direction the world is moving toward. The mobile phone changed the face of communication and enabled more people to reach more other people than ever before. The big four banks in South Africa represent 83.5 per cent of the total asset value of all banks in South Africa. Traditionally, banking customers (or potential customers) could be reached through the current 2 786 branches, 19 451 ATMs and potentially 4.59 million internet users. There are 47.9 million mobile phone subscribers in South Africa – increasing the number of potential contact points by order of magnitude. The possibilities for banks utilising the mobile phone are endless, however online banking and offering banking services through a mobile phone is increasingly more subject to fraud attacks. Online banking and credit card fraud is still on the increase. Today, SMS is used to alert customer of movements on their bank account. This keeps the customer informed and enables them to notify their banks and prevent subsequent fraudulent transactions. SMS can be sent from one mobile phone to another (P2P) or from a computer system to a mobile phone (A2P). In 2007, 2 trillion SMS's were sent worldwide and was responsible for 75 to 80 per cent of all mobile phone revenues. South Africa sent 34 billion A2P SMS in 2009 of which 29 per cent were sent as transactional SMS by the top three banks in South Africa. SMS-based transactional alerts are SMS sent each time a change occurs in a bank account, for example, when your credit card is used then you will get an SMS on your mobile phone. Each bank makes different functionalities available. Absa reported 2 million customers receiving SMS alerts in 2008. FNB reported 67 million transactional SMS per month in 2009. The core advantages for using transactional SMS are the cost, reliability and ubiquity. Research was conducted among five of the six largest banks. Data revealed that banks send between 16 million and 69.4 million SMS per month and have approximately between 4.5 and 5.1 million customers using this service. The impact was tested through personal interviews. The two common factors were fraud reduction and customer retention. The two key challenges the banks identified are: i) Capacity/throughput with the mobile network operators; and ii) Getting internal systems and processes defined and working together for the alerts. The advantages identified are competitive positioning, customer interaction, empowerment of people and revenue. Key findings of the research were: SMS-based transactional alerts offer strategic importance; Any system is as good as it is being utilised; Security controls are extremely complex; SMS capacity is a common challenge and big risk; Internal processes cause the most complexity; Return on investment is not adequately measured; Transactional alerts is a potential revenue stream; There is no interaction between the bank and the customer; SMS in South Africa create high dependencies; SMS-based transactional alerts are successful.

<p>This thesis investigates the use of mobile phones as service-delivery devices in a sign language machine translation system. Four sign language visualization methods were evaluated on mobile phones. Three of the methods were synthetic sign language visualization methods. Three factors were considered: the intelligibility of sign language, as rendered by the method / the power consumption / and the bandwidth usage associated with each method. The average intelligibility rate was 65%, with some methods achieving intelligibility rates of up to 92%. The average le size was 162 KB and, on average, the power consumption increased to 180% of the idle state, across all methods. This research forms part of the Integration of Signed and Verbal Communication: South African Sign Language Recognition and Animation (SASL) project at the University of the Western Cape and serves as an integration platform for the group's research. In order to perform this research a machine translation system that uses mobile phones as service-delivery devices was developed as well as a 3D Avatar for mobile phones. It was concluded that mobile phones are suitable service-delivery platforms for sign language machine translation systems.</p>

Several emerging wireless communication systems require direct transmission between mobile terminals to support efficient data transfer and user mobility. Such mobile-to-mobile communication systems differ from the conventional cellular systems where only the user unit is mobile. In addition, there might be a relay, also called a repeater, between the original transmitter and the final receiver to improve the network range and coverage. Potential applications for mobile-to-mobile systems include Intelligent Highways for coordinated traffic control and ad-hoc networks meant for military and disaster management. Relays may be deployed in cellular networks and IEEE 802.16 mesh networks for wireless broadband access. Extensive research in cellular radio channels has led to the successful deployment of cellular networks. However, our knowledge of the radio channels encountered in mobile-to-mobile and relay-based systems is still inadequate. This forms the primary motivation behind our research in addressing wireless channel modeling, simulation, and estimation issues for these systems. Specifically, we investigate frequency-flat mobile-to-mobile channels and develop simulation models by using the sum-of-sinusoids method, which is widely used for cellular channels. In addition, we present the properties of amplify and forward relay channels via theoretical analysis. This analysis, to the best of our knowledge, is the first of its kind. Further, we address the unique challenges, which arise because of the different underlying channel model, for channel estimation in amplify and forward relay systems. Our work would provide other researchers the necessary tools for the design and testing of these emerging communication systems.