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  • 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.
31

Atlantic : a framework for anomaly traffic detection, classification, and mitigation in SDN / Atlantic : um framework para detecção, classificação e mitigação de tráfego anômalo em SDN

Silva, Anderson Santos da January 2015 (has links)
Software-Defined Networking (SDN) objetiva aliviar as limitações impostas por redes IP tradicionais dissociando tarefas de rede executadas em cada dispositivo em planos específicos. Esta abordagem oferece vários benefícios, tais como a possibilidade de uso de protocolos de comunicação padrão, funções de rede centralizadas, e elementos de rede mais específicos e modulares, tais como controladores de rede. Apesar destes benefícios, ainda há uma falta de apoio adequado para a realização de tarefas relacionadas à classificação de tráfego, pois (i) as características de fluxo nativas disponíveis no protocolo OpenFlow, tais como contadores de bytes e pacotes, não oferecem informação suficiente para distinguir de forma precisa fluxos específicos; (ii) existe uma falta de suporte para determinar qual é o conjunto ótimo de características de fluxo para caracterizar um dado perfil de tráfego; (iii) existe uma necessidade de estratégias flexíveis para compor diferentes mecanismos relacionados à detecção, classificação e mitigação de anomalias de rede usando abstrações de software; (iv) existe uma necessidade de monitoramento de tráfego em tempo real usando técnicas leves e de baixo custo; (v) não existe um framework capaz de gerenciar detecção, classificação e mitigação de anomalias de uma forma coordenada considerando todas as demandas acima. Adicionalmente, é sabido que mecanismos de detecção e classificação de anomalias de tráfego precisam ser flexíveis e fáceis de administrar, a fim de detectar o crescente espectro de anomalias. Detecção e classificação são tarefas difíceis por causa de várias razões, incluindo a necessidade de obter uma visão precisa e abrangente da rede, a capacidade de detectar a ocorrência de novos tipos de ataque, e a necessidade de lidar com erros de classificação. Nesta dissertação, argumentamos que SDN oferece ambientes propícios para a concepção e implementação de esquemas mais robustos e extensíveis para detecção e classificação de anomalias. Diferentemente de outras abordagens na literatura relacionada, que abordam individualmente detecção ou classificação ou mitigação de anomalias, apresentamos um framework para o gerenciamento e orquestração dessas tarefas em conjunto. O framework proposto é denominado ATLANTIC e combina o uso de técnicas com baixo custo computacional para monitorar tráfego e técnicas mais computacionalmente intensivas, porém precisas, para classificar os fluxos de tráfego. Como resultado, ATLANTIC é um framework flexível capaz de categorizar anomalias de tráfego utilizando informações coletadas da rede para lidar com cada perfil de tráfego de um modo específico, como por exemplo, bloqueando fluxos maliciosos. / Software-Defined Networking (SDN) aims to alleviate the limitations imposed by traditional IP networks by decoupling network tasks performed on each device in particular planes. This approach offers several benefits, such as standard communication protocols, centralized network functions, and specific network elements, such as controller devices. Despite these benefits, there is still a lack of adequate support for performing tasks related to traffic classification, because (i) the native flow features available in OpenFlow, such as packet and byte counts, do not convey sufficient information to accurately distinguish between some types of flows; (ii) there is a lack of support to determine what is the optimal set of flow features to characterize different types of traffic profiles; (iii) there is a need for a flexible way of composing different mechanisms to detect, classify and mitigate network anomalies using software abstractions; (iv) there is a need of online traffic monitoring using lightweight/low-cost techniques; (v) there is no framework capable of managing anomaly detection, classification and mitigation in a coordinated manner and considering all these demands. Additionally, it is well-known that anomaly traffic detection and classification mechanisms need to be flexible and easy to manage in order to detect the ever growing spectrum of anomalies. Detection and classification are difficult tasks because of several reasons, including the need to obtain an accurate and comprehensive view of the network, the ability to detect the occurrence of new attack types, and the need to deal with misclassification. In this dissertation, we argue that Software-Defined Networking (SDN) form propitious environments for the design and implementation of more robust and extensible anomaly classification schemes. Different from other approaches from the literature, which individually tackle either anomaly detection or classification or mitigation, we present a management framework to perform these tasks jointly. Our proposed framework is called ATLANTIC and it combines the use of lightweight techniques for traffic monitoring and heavyweight, but accurate, techniques to classify traffic flows. As a result, ATLANTIC is a flexible framework capable of categorizing traffic anomalies and using the information collected to handle each traffic profile in a specific manner, e.g., blocking malicious flows.
32

Policy-driven Security Management for Gateway-Oriented Reconfigurable Ecosystems

January 2015 (has links)
abstract: With the increasing user demand for low latency, elastic provisioning of computing resources coupled with ubiquitous and on-demand access to real-time data, cloud computing has emerged as a popular computing paradigm to meet growing user demands. However, with the introduction and rising use of wear- able technology and evolving uses of smart-phones, the concept of Internet of Things (IoT) has become a prevailing notion in the currently growing technology industry. Cisco Inc. has projected a data creation of approximately 403 Zetabytes (ZB) by 2018. The combination of bringing benign devices and connecting them to the web has resulted in exploding service and data aggregation requirements, thus requiring a new and innovative computing platform. This platform should have the capability to provide robust real-time data analytics and resource provisioning to clients, such as IoT users, on-demand. Such a computation model would need to function at the edge-of-the-network, forming a bridge between the large cloud data centers and the distributed connected devices. This research expands on the notion of bringing computational power to the edge- of-the-network, and then integrating it with the cloud computing paradigm whilst providing services to diverse IoT-based applications. This expansion is achieved through the establishment of a new computing model that serves as a platform for IoT-based devices to communicate with services in real-time. We name this paradigm as Gateway-Oriented Reconfigurable Ecosystem (GORE) computing. Finally, this thesis proposes and discusses the development of a policy management framework for accommodating our proposed computational paradigm. The policy framework is designed to serve both the hosted applications and the GORE paradigm by enabling them to function more efficiently. The goal of the framework is to ensure uninterrupted communication and service delivery between users and their applications. / Dissertation/Thesis / Masters Thesis Computer Science 2015
33

Analýza a návrh distribuční B2B, B2C aplikace / Analysis and Design of Distributional B2B and B2C Application

Novák, Jiří January 2010 (has links)
The diploma thesis is concerned with an analysis and design of distributional B2B and B2C application. The fundamental part is especially focused on design of features and functions of the application, selection of suitable technologies and the project of the data storage. The diploma paper also contains a scheme of administration of particular versions and binding regulations for development and resulting maintainance and expanding of the application.
34

A managerial framework for the enablement of the performance of virtual knowledge workers

Luyt, Karen 29 April 2013 (has links)
With the increasing use of mobile technologies in modern organisations, managers are facing the dilemma of having to manage the performance of individuals who are removed from their direct sphere of control, while using performance management principles that have not necessarily been adapted to accommodate this. The study investigated, analysed and described the management and measurement of the performance of these virtual knowledge workers from the perspective of the manager, with the aim of proposing a new conceptual framework to assist managers in this task. In addition, the study identified the organisational context and individual contribution required to support such a framework. The study used a constructivist grounded theory framework, with the aim of building theory through an inductive approach rather than testing existing theory. An embedded, multiple-case study research design was used to execute the study, comprising five companies in the Information and Communications Technology and related sectors in South Africa. Quantitative and qualitative data were collected at the organisational, team and individual levels. In total, 39 interviews were qualitatively analysed using content analysis aided by ATLAS.ti. The 163 questionnaires were quantitatively analysed using descriptive statistical methods. Thereafter, within-case and cross-case analyses were performed to extract themes and to propose a conceptual framework for the enablement of the performance of virtual knowledge workers. The research uncovered four key findings. The first finding was that the concept of "virtual" in the term virtual worker is often misunderstood, and that the definition should be applied on a continuum of virtuality, leading to the concept of perceived and true virtuality. The second finding was that true virtuality influences how performance is perceived, and how deliverables and metrics contribute to perceived, actual and true performance. The third finding was that parameters affecting virtual performance include organisational, contextual, and customer factors, as well as the managerial approach itself. The manager needs to become the mediator for these parameters, thereby fulfilling the role of enabler of virtual performance. The fourth finding was that the visual or face-to-face element still remains important when managing the performance of virtual knowledge workers. The study makes a significant contribution on a theoretical level by extending existing theoretical models regarding virtual distance and the management of dispersed teams into a much more comprehensive model. This concentric performance enablement model for virtual knowledge workers shows how the manager acts as enabler for the true performance of the virtual knowledge workers. On a methodological level, the research demonstrates how an embedded, multiple-case study, executed on three levels of analysis, and based on a grounded theory approach, can be executed to develop theoretical insights into the complex phenomenon of enabling the performance of virtual knowledge workers; and lastly the study has also made a contribution on the level of practice, by giving managers a conceptual framework and practical recommendations on how to manage and enable the performance of virtual knowledge workers. / Thesis (PhD)--University of Pretoria, 2012. / Human Resource Management / unrestricted
35

Actors affecting financial sustainability of water and sewerage provision in Ccape Town, South Africa

Beda, Mthandazo January 2019 (has links)
Thesis (MTech (Business Administration))--Cape Peninsula University of Technology, 2019 / Financial sustainability of water and sewerage provision is undermined by consumers’ inability and reluctance to pay service fees. Consequently, the escalation of operational and maintenance costs of water and sewerage provision is a major challenge facing South African municipalities. This study examines the provision of water and sewerage services and presents a strategic framework to manage revenue collection to achieve water and sewerage provision financial sustainability. The study applied interpretive epistemology research method. Content analysis was used to collect and analyse data for an improved understanding of service provision and revenue collection mantra. Unlike the other method such as the exploratory research method that provides a description of the observed phenomenon, an interpretive epistemology methodology provides deeper insights into management strategies that are required in order to achieve sustainable water and sewerage provision. The main objective of this study was to investigate factors affecting financial sustainability of water and sewerage provision in Cape Town. The qualitative data were analysed using content method of analysis to gain better meaning of the phenomenon being studied. The results show that although the water and sanitation department of the participating organisation is making efforts to generate revenue through implementing water and sanitation services payments, there are some residents who refuse to pay for services, resulting in revenue loss. The other reason for loss of revenue is unaccounted water which is the focus of the water and sewerage, demand management and strategy section; this is as a result of leaks, illegal connections, unregistered car wash bays, unmetered connections and informal settlement areas which do not get enough subsidies. The reasons advanced for unwillingness to pay for water and sanitation services by consumers were unemployment, poverty, unequal distribution of services and general ignorance. This study has found evidence of a reluctance toward service payment by participating consumers – requiring strategies to encourage rates payments.
36

A Leadership Approach to Successful Digital Transformation Using Enterprise Architecture

Weisman, Robert 20 December 2019 (has links)
Digital transformation has been a focus of public and private sectors to both improve and sustain business value by leveraging rapidly evolving technology. Digital technology is ubiquitous and inter-connected, changing the face of business, government and society through the creation of new industries, with automation replacing two thirds of existing jobs. The challenge is that most digital transformation efforts fail, mainly due to inadequate leadership and management as well as failure to accept that it is a multi-disciplinary problem. Another challenge is to distinguish between digital transformation (DT) and digitization where the former is based on a customer-centric value proposition and the latter focuses on cost-cutting and operational excellence. This difference also highlights the business/technology divide where the former is mainly DT and the latter is mainly digitization. The challenge addressed in this thesis is how to obtain management acceptance that digital transformation is multi-disciplinary and to make recommendations with respect to how best to achieve DT goals. The research methods followed is a blend of participatory action research (PAR), case study analysis and literature analysis. The principal research findings are that there is no single, management methodology that can increase the chances of DT success but that a modified form of enterprise architecture (EA) that collaboratively interacts with the other management frameworks can likely provide a solid foundation to effectively achieve DT. The thesis consists of an assessment of the current methodologies, four articles that each discuss an area to support effective DT, followed by a request for change (RFC) to up-date the TOGAF 9 EA framework standard. TOGAF was selected due to its pervasive usage globally (80% of Fortune 50 and 60% of Fortune 500). The RFC accommodated both the concepts raised in the articles and other innovations highlighted in the literature review and assessment. The thesis concludes that enterprise architecture is a key business technique that al-lows the sharing of core decision support information across the enterprise, enabling all management frameworks, especially those on the technology-management divide, to collaboratively realize digital transformation.
37

Development of a health safety and environment (HSE) performance review. Methodology for the oil and gas industry in Libya

Ahmed, Giuma A.A. January 2016 (has links)
The oil and gas industry in Libya has suffered a number of health and safety accidents including environmental disasters due to the nature of the work involved and the hazardous materials it handles in all facets of exploration and production. Such issues have hitherto not received due attention by the Libyan Authorities. The fact that strict HSE assessment standards are neither well-defined nor established in Libya is not helpful. Furthermore, oil and gas industry in new free Libya has suffered immensely during the 2011 Arab Spring and its rebuilding poses a number of critical HSE challenges. The purpose of the research is to develop and validate a HSE Performance Review Methodology for Libyan oil and gas industry based on clearly defined and measurable aspects for assessment. The thesis starts by performing a comprehensive literature review on all aspects of HSE including universal standards. The review indicates that there is a gap in respect of semi-qualitative methods for assessing HSE performance commensurate with other disciplines. The thesis then identifies four key research problems in the context of Libyan oil and gas industries. Based on these problems, an empirical research was conducted and included three distinct Stages. Stage 1 consisted of a pilot study based on an interview questionnaire with 15 experienced HSE professionals working in oil and gas companies in Libya to help identify key issues pertaining to HSE assessment. Data analysis results for Stage 2 have been used to derive a list of 12 main groups of HSE questions which have then been tested on 84 HSE professionals working in Libya stemming from 35 medium and large oil and gas companies. Modal distribution analyses have been performed to scope down the number of HSE performance factors, which would then be used in Stage 3 of the empirical research. This consisted of issuing the same 84 interviewees with a questionnaire requesting their assessment of how Critical, Important and Less Important were the 60 factors identified. Central Tendency, Variation Ratios and Indices of Diversity were used to successfully analyse the data. With the QAA Subject Review in mind as a potential model for the sought methodology, and a mapping of the four research problems with data analysis results from Stages 1, 2 and 3; six HSE Performance Review Aspects emerged: Prevention, Surveillance, Response, Achievements, Resource and HSE Management and Enhancement – judged and graded using a 1 to 4 scale. The HSE Performance Review methodology has been validated by direct application to five comprehensive studies starting from the self-assessment document written by the companies, an extensive review visit by peer-assessors and a final report showing grades, benchmarks and shortcomings. Lessons learned from the validation exercise have been used to revise the definition of the six Aspects and used to propose an appropriate implementation plan in Libya. The results of the validation exercise are very encouraging and readily confirm that the methodology can be applied to other industry sectors.
38

Development of a quality management system framework for dental assisting education in South Africa

Muslim, Tufayl Ahmed 28 May 2014 (has links)
Submitted in fulfilment of the requirements of the Degree of Master of Technology: Quality, Durban University of Technology, 2014. / There has been a call from society for both the provision of a quality education and for a quality “student” who can contribute to the economy and citizenry of South Africa. It therefore makes sense for any educational structure to develop and adopt, strategies and systems in order to meet these new calls, and to provide technologically relevant education that will meet the demands of modern society. This has led to a renewed need for consistency, conformity and quality within higher education. Concerns about students’ capabilities have been raised, and have led to questions about the accountability of higher education institutions. A quality management system framework may ensure that these higher education structures are able to deliver a quality education to their external and internal customers. This research investigated the current quality management systems used in dental assisting both locally and world-wide, and then developed a quality management system framework to suit South African conditions. An action research study, using data gathered from a purposive census sample, and data obtained by means of a mixed-method approach, was conducted in two phases. A preliminary study (Part A) was conducted amongst the four South African dental assisting education programme providers and deficiencies in the quality management systems of these programmes were identified. The preliminary work (Part B) in this study consisted of a comparative analysis of the quality management systems of a convenience sample of dental assisting education providers in twenty countries. Both good practices and deficiencies in practices were identified. A further review of the literature identified possible solutions to improve the quality of the dental assisting education programmes, and was used as the foundation for the development of the Dental Assisting Higher Education – Quality Management Framework (DAHE-QMF). The results of the preliminary study - the comparative analysis and the literature review - revealed that the development and implementation of a quality management system framework for dental assisting in South Africa could lead to an improvement of the standards of training, and thus the competence of the student. The framework will be presented to the four programme leaders at the four Universities of Technology that offer dental assisting education for their consideration of partial/total adaptation of the framework.
39

A modelling process of short-term interest rate risk management for the South African commercial banking sector

Sun, Jiaqi 03 1900 (has links)
Thesis (MComm (Business Management))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: This study focuses on banking book interest rate risk management, more specifically shortterm interest rate risk management problems. This type of risk is induced by the inflation targeting policy of the South African Reserve Bank. As a result, inflation leads to an uncertain interest rate cycle and a period of uncertain interest rate levels as it relates to lending and borrowing products in the South African commercial banking sector. The lending rates of most South African commercial banks are tied to the prime overdraft rate. The borrowing rates are linked to the money market rates such as the Johannesburg Interbank Agreed Rate (JIBAR) which is indirectly affected by the prime overdraft rate. Hence, lending and borrowing rates are related to the repo-rate. Furthermore, a fixed relationship exists between the prime overdraft rate and the repo-rate. The monetary policy committee meets every two months during the year to make inflation and repo-rate adjustments, as stipulated in the inflation targeting policy. A subject portfolio containing fixed-rate loans, advances and floating-rate deposits is exposed to the change of the repo-rate. This short-term banking book interest rate risk is defined based on the fact that the repo-rate adjustment occurs every two months, the banking book risk management is short term focused, and hedging instruments against interest rate risk are short term dated contracts. Such a short term risk may have a negative impact on the bank’s profitability. The study starts with a review of the bank risk management processes, and then discusses the enterprise risk management framework that guides the formation of the risk management processes and systems. In order to benchmark against international risk management practices, a comparative analysis is carried out to evaluate the risk management tendencies of bank risk management in South Africa and globally. The empirical findings reveal that most banks (i.e. eighty per cent of all local banks) manage the short-term interest rate risk by following the same process as the interest rate risk in general. The key elements (risk identification, measurement, mitigation and monitoring and reporting) of the banking book interest rate risk management are not linked together as a systematic process. This is not in line with the Basel II Accord to manage market risks through a process approach. The study also proposes a generic short-term interest rate risk management framework and in doing so, addresses some of the weaknesses of current risk management practices. Based on this framework, the South African banks may develop their own processes to manage such short-term banking book interest rate risk exposure. Some of the problems of bank risk management that come to light from the empirical findings, are summarised in the last chapter and may be considered for future research. / AFRIKAANSE OPSOMMING: Hierdie studie fokus op die probleme van die bankboek rentekoersrisikobestuur, meer spesifiek die korttermyn rentekoers risikobbestuursprobleme. Hierdie tipe risiko word deur die inflasieteikenraamwerk beleid van die Suid-Afrikaanse Reserwebank veroorsaak. Dit veroorsaak ‘n tydperk van onsekere rentekoersvlakke veral sover dit uitleen- en leenprodukte in die Suid-Afrikaanse kommersiële banksektor aangaan. Die uitleenkoerse van die meeste Suid-Afrikaanse kommersiële banke is aan die prima bankoortrekkingskoers gekoppel. Die leningstariewe is aan die geldmarkkoerse soos die Johannesburgse Interbank Ooreengekome Koers (JIBOK) gekoppel wat indirek geraak word deur die prima bankoortrekkingskoers. Uitleen- en leenkoerse is redelik afhanklik van die repo-koers waar laasgenoemde ‘n redelike vaste verwantskap met die prima bankoortrekkingskoers het. Die monetêre beleidkomitee vergader elke twee maande van die jaar om inflasie en repokoers aanpassings te maak, ooreenkomstig die inflasieteiken beleid. 'n Bepaalde portefeulje met vasterente lenings, voorskotte en vlottende koers deposito’s is blootgestel aan die verandering in die repokoers. Hierdie korttermyn rentekoersrisiko van die bankboek word gedefinieer op grond van die feit dat die repo-koers aanpassing elke twee maande gebeur. Die bankboek risikobestuur het ‘n korttermyn fokus, en verskansingsinstrumente teen rentekoersrisiko is korttermyn kontrakte. So 'n korttermyn risiko kan 'n negatiewe impak op die bank se winsgewendheid hê. In hierdie studie word bankrisikobestuur prosesse beskou. Die risikobestuursraamwerk wat die basis vorm van die risikobestuursprosesse en stelsels word aangespreek. Om 'n idee te vorm van die huidige internasionale risikobestuurspraktyke of tendense by banke, word die state van internasionale en oorsese banke kortliks beskou. Die empiriese bevindinge uit die opname dui daarop dat die meeste banke (d.w.s tagtig persent van alle plaaslike banke) die korttermyn rentekoersrisiko nie afsonderlik van rentekoersrisikobestuur in die algemeen bestuur nie. Die sleutelelemente van die risikobestuursproses (risiko identifisering, mitigasie, implementering, monitering en verslagdoening) kom wel voor maar die bankboek rentekoersrisikobestuur is nie gekoppel as 'n sistemastiese proses nie. Dit blyk dat hierdie situasie na alle waarskynlikheid nie in lyn is met die Basel II akkoord om markrisiko's deur 'n prosesbenadering, te bestuur nie. Die studie stel ook ‘n generiese raamwerk voor vir die bestuur van korttermyn rentekoersrisiko wat dan ook van die swakhede van die huidige risikobestuurspraktyke aanspreek. Op grond van hierdie raamwerk, kan die Suid-Afrikaanse banke dit oorweeg om hul eie prosesse te ontwikkel vir die bestuur van bankboek rentekoersrisiko blootstelling. Sommige navorsingsprobleme van bank risikobestuur wat uit die empiriese bevindinge aan die lig gekom het, word in die laaste hoofstuk opgesom en kan vir verdere navorsing in die toekoms oorweeg word.
40

Energy efficient wired networking

Chen, Xin January 2015 (has links)
This research proposes a new dynamic energy management framework for a backbone Internet Protocol over Dense Wavelength Division Multiplexing (IP over DWDM) network. Maintaining the logical IP-layer topology is a key constraint of our architecture whilst saving energy by infrastructure sleeping and virtual router migration. The traffic demand in a Tier 2/3 network typically has a regular diurnal pattern based on people‟s activities, which is high in working hours and much lighter during hours associated with sleep. When the traffic demand is light, virtual router instances can be consolidated to a smaller set of physical platforms and the unneeded physical platforms can be put to sleep to save energy. As the traffic demand increases the sleeping physical platforms can be re-awoken in order to host virtual router instances and so maintain quality of service. Since the IP-layer topology remains unchanged throughout virtual router migration in our framework, there is no network disruption or discontinuities when the physical platforms enter or leave hibernation. However, this migration places extra demands on the optical layer as additional connections are needed to preserve the logical IP-layer topology whilst forwarding traffic to the new virtual router location. Consequently, dynamic optical connection management is needed for the new framework. Two important issues are considered in the framework, i.e. when to trigger the virtual router migration and where to move virtual router instances to? For the first issue, a reactive mechanism is used to trigger the virtual router migration by monitoring the network state. Then, a new evolutionary-based algorithm called VRM_MOEA is proposed for solving the destination physical platform selection problem, which chooses the appropriate location of virtual router instances as traffic demand varies. A novel hybrid simulation platform is developed to measure the performance of new framework, which is able to capture the functionality of the optical layer, the IP layer data-path and the IP/optical control plane. Simulation results show that the performance of network energy saving depends on many factors, such as network topology, quiet and busy thresholds, and traffic load; however, savings of around 30% are possible with typical medium-sized network topologies.

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