In network design, a communication network is optimized for a given set of parameters like cost, reliability and delay. This study analyzes network design problem using Genetic Algorithms in detail and makes comparison of different approaches and representations. Encoding of a problem is one of the most crucial design choices in Genetic Algorithms. For network design problem, this study compares adjacency matrix representation with list of edges representation. Also, another problem is defining a fair fitness function that will not favor one optimization parameter to the other. Multi-objective optimization is a recommended solution for such problems. This study describes and compares some of those approaches for different combinations in network design problem.

Many-core architectures provide an efficient way of harnessing the growing numbers of transistors available in modern fabrication processes; however, the parallel programs run on these platforms are increasingly limited by the energy and latency costs of communication. Existing designs provide a functional communication layer but do not necessarily implement the most efficient solution for chip-multiprocessors, placing limits on the performance of these complex systems. In an era of increasingly power limited silicon design, efficiency is now a primary concern that motivates designers to look again at the challenge of cache coherence. The first step in the design process is to analyse the communication behaviour of parallel benchmark suites such as Parsec and SPLASH-2. This thesis presents work detailing the sharing patterns observed when running the full benchmarks on a simulated 32-core x86 machine. The results reveal considerable locality of shared data accesses between threads with consecutive operating system assigned thread IDs. This pattern, although of little consequence in a multi-node system, corresponds to strong physical locality of shared data between adjacent cores on a chip-multiprocessor platform. Traditional cache coherence protocols, although often used in chip-multiprocessor designs, have been developed in the context of older multi-node systems. By redesign- ing coherence protocols to exploit new patterns such as the physical locality of shared data, improving the efficiency of communication, specifically in chip-multiprocessors, is possible. This thesis explores such a design - Proximity Coherence - a novel scheme in which L1 load misses are optimistically forwarded to nearby caches via new dedicated links rather than always being indirected via a directory structure.

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This thesis presents the computer implementation of a multi resolutional concurrent, design inference network, whose nodes are refined by PNDN (Petri Net Based Design Inference Network) modules. The extended design network is named as N-PNDN and consists of several embedded PNDN modules which models the information flow on a functional basis to facilitate the design automation at the conceptual design phase of an engineering design. Information flow in N-PNDN occurs between parent and child PNDN modules in a hierarchical structure and is provided by the token flow between the modules. In this study, computer implementation of the design network construction and token flow algorithms for the N-PNDN structure is restored and therefore the previous DNS (Design Network Simulator) is adapted for the multi layer design and decomposition of mechatronic products. The related algorithms are developed by using an object oriented, visual programming environment. The graphical user interface is also modified. The further developed DNS has been used for the application of the N-PNDN structure in the conceptual design of 5 mechatronic systems. In the guidance of this study, it has been understood that the further developed DNS is a powerful tool for designers coming from different engineering disciplines in order to interchange their ideas.

For ensuring network survivability in case of single component failures many routing protocols provide a primary and a back up routing path for each origin destination pair. We address the problem of selecting these paths such that in the event of multiple failures, occuring with given probabilities, the total loss in routable demand due to both paths being intersected is small with high probability. We present a chance constraint model and solution approaches based on an explicit integer programming formulation, a robust formulation and a cutting plane approach that yield reasonably good solutions assuming that the failures are caused by at most two elementary events, which may each affect several network components.

The growth in the interdependence and complexity of socio-technical systems requires the development of tools and techniques to aid in the formulation of better policies. The efforts of this research focus towards developing methodologies and support tools for better policy design and formulation. In this thesis, a new framework and a systematic approach for the formulation of policies are proposed. Focus has been directed to the interactions between policy measures, inspired by concepts in process design and network analysis. Furthermore, we have developed an agent-based approach to create a virtual environment for the exploration and analysis of different configurations of policy measures in order to build policy packages and test the effects of changes and uncertainties while formulating policies. By developing systematic approaches for the formulation and analysis of policies it is possible to analyse different configuration alternatives in greater depth, examine more alternatives and decrease the time required for the overall analysis. Moreover, it is possible to provide real-time assessment and feedback to the domain experts on the effect of changes in the configurations. These efforts ultimately help in forming more effective policies with synergistic and reinforcing attributes while avoiding internal contradictions. This research constitutes the first step towards the development of a general family of computer-based systems that support the design of policies. The results from this research also demonstrate the usefulness of computational approaches in addressing the complexity inherent in the formulation of policies. As a proof of concept, the proposed framework and methodologies have been applied to the formulation of policies that deal with transportation issues and emission reduction, but can be extended to other domains.

The aim of this master's thesis is to design a language through which it would be possible to monitor a stream of network flows in order to detect network policy violations in the local network. An analysis of the languages used in the data stream management systems and an analysis of tasks submitted by the potential administrator were both carried out. The analysis specified resulted in the language design which represents pipelining consisting of filtering and aggregation. These operations can be clearly defined and managed within security rules. The result of this thesis also results in the Policer modul being integrated in the NEMEA system, which is able to apply the main commands of the proposed language. Finally, the module meets the requirements of the specified tasks and may be used for further development in the area of monitoring network policies.