M. Tech. Business Administration / The advent of information technology has significantly influenced and changed how businesses are being managed and monitored today. Information technology functions have strived tirelessly to understand demand, set priorities, deliver effectively, and capture value, yet the results still disappoint. Company ABC is currently operating within a market that calls for better use of its assets in order to reduce costs and improve its operations. The information technology function is seen as a strategic asset for ABC and needs to be assessed to determine the level of capability so that it can make a meaningful contribution towards achieving various business objectives. This study sought to assess various information technology functions to determine their level of capability. An analysis was done of the company's information technology processes based on the control objectives for information and related technology (COBIT) framework. The study also highlights the status of ABC's information technology systems and determines what control should be established. Finally it sought to assist the organisation in satisfying its quality, fiduciary and security requirements for their information assets.

The recent proliferation of personal wireless devices has led to the emergence of disruption-tolerant networks (DTNs), which are characterized by intermittent connectivity among some or all participating nodes and a consequent lack of contemporaneous end-to-end paths between the source and consumer of information. However, the success of DTNs as a communication paradigm is critically dependent on the following challenges being addressed: (1) How to enable popular but demanding applications, such as video-on-demand, to operate in such constrained network settings, and (2) How to incentivize individual devices to cooperate when network operation is only possible under, or greatly benefits from cooperation. In this dissertation, we present a novel set of protocols and develop real systems that effectively meet the above challenges. We make the following contributions: First, we design and implement a novel system for enabling high bandwidth content distribution in vehicular DTNs by leveraging infrastructure access points (APs). We predict which APs will soon be visited by a vehicular node and then proactively push content-of-interest to those APs. Our replication schemes optimize content delivery by exploiting Internet connectivity, local wireless connectivity, node relay connectivity and mesh connectivity among APs. We demonstrate the effectiveness of our system through trace-driven simulation and Emulab emulation using real taxi and bus traces. We further deploy our system in two vehicular networks: a fourteen AP 802.11b network and a four AP 802.11n network with smartphones and laptops as clients. Second, we propose an incentive-aware routing protocol for DTNs. In DTNs, routing takes place in a store-and-forward fashion with the help of relay nodes. If the nodes in a DTN are controlled by rational entities, such as people or organizations, the nodes can be expected to behave selfishly by attempting to maximize their utilities and conserve their resources. Since routing is inherently a cooperative activity, system operation will be critically impaired unless cooperation is incentivized. We propose the use of pair-wise tit-for-tat (TFT) as a simple, robust and practical incentive mechanism for DTNs. We then develop an incentive-aware routing protocol that allows selfish nodes to maximize their own performance while conforming to TFT constraints. / text

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published_or_final_version / abstract / toc / Electrical and Electronic Engineering / Master / Master of Philosophy

published_or_final_version / abstract / toc / Electrical and Electronic Engineering / Master / Master of Philosophy

published_or_final_version / Computer Science / Master / Master of Philosophy

published_or_final_version / Computer Science / Master / Master of Philosophy

The increase in the interconnection of computers has led to a corresponding increase in the complexity of effective network design. This increase is partly to the size and diversity of computer networks, but also is due to the proliferation of available network hardware and software. As with any system, computer networks are made up of various interrelated components, all of which are essential to the network design process. Some of these components are physical in nature, that is, they specify a piece of hardware or software with certain perfomance properties. Other components are considered to be logical elements of network design. The problem of designing, implementing and controlling present and planned data communication networks is rapidly exceeding manual planning and design capabilities. Network managers and designers are looking more and more to computer resources to manage the volume of traffic information, to develop and evaluate network configurations, and to assist in allocating and placing control functions among network processors. The number of network alternatives is increasing so fast that the demand for network optimization--both in private network design and in the interface to, and use of, public network facilities--can be satisfied only through computer aids. These aids range from simple scratch-pad systems that store and compile network statistics to complete traffic emulators, design configurators, and software for data-distribution modelling. Network design generates a set of performance/cost tradeoffs for an existing or proposed network. The network design process generates and regenerates these performance curves in response to changes in critical design parameter such as protocols, line capacity, concentration points, host processor capability and message routing techniques. This dissertation considers the development of a generalized model of the network design process. This model proposes that the physical and logical network components can be described using a set of objects, properties and relationships. Objects are used to describe network physical and logical components. These components are given properties, thus associating with each object a set of network descriptions. Linkages between objects or classes of objects are provided by object-object relationships. The prototype system provides a generalized network design tool which allows a concise and explicit statement of network requirements providing a network planning and design model which is independent of any particular network or application.

This thesis presents an implementation of the model base concept in SIMSCRIPT II.5. It shows two principles in designing a flexible general simulation system. First of all, the input and output port intercommunication and synchronization should be done by an I/O coupling scheme, i.e. a coordinator. Second, every input port should be a separate file in the model base. Users can retrieve these files to couple them together and evaluate the simulation run. A well-designed computer network model base is shown through several examples. It will help the computer network system design to be done in a modular, hierarchical, coordinated fashion.