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This thesis describes the application of the stochastic-flow-modeling (SFM) approach to represent the quality behavior of a manufacturing system. Initially, a simple, one-product type SFM is discussed and then a more complex multiple-product manufacturing system is developed. This quality SFM-based model has aggregation by station, product, and operational shift. Subsequently, potential supervisory control architectures that could be used in conjunction with this quality-based SFM are discussed and developed. Distribution parameter fitting is explored using static and adaptive approaches and a comparison between these two approaches is given. Then, the accuracy of the SFM modeling technique is demonstrated using two simulation examples. Effective equipment maintenance is essential for a manufacturing plant seeking to produce high quality products. The impact of equipment reliability and quality on throughput have been well established, but the relationship between maintenance and quality is not always clear nor direct. Therefore, after developing a SFM to represent the quality of a manufacturing system, the focus of this work shifts towards identifying correlations between maintenance and quality. This thesis describes a statistical modeling method that makes use of a Kalman filter to identify correlations between independent sets of maintenance and quality data. With such a method, maintenance efforts can be better prioritized to satisfy both production and quality requirements. In addition, this method is used to compare results from the theoretical maintenance-quality model to data from an actual manufacturing system. Results of the analysis indicate the potential for this method to be applied to preventive, as well as reactive maintenance decisions, since ageing aspects of equipment are also considered in the model. / Thesis (Master, Chemical Engineering) -- Queen's University, 2008-06-25 11:18:16.925

Multiplayer games have to support activities which have differing usability requirements. The usability of the system is directly influenced by the choice of consistency maintenance algorithm. These algorithms must accommodate usability requirements while ensuring shared data is accurately replicated. We demonstrate that consistency maintenance in games can be organized around the AMP properties which state that separate nodes can maintain their instances of shared data using different algorithms (asymmetry), multiple consistency maintenance algorithms can be used within an application (multiplicity), and that consistency maintenance algorithms should be created as modular components (plug-replaceability). The motivation for AMP is outlined with a review of examples from commercial 3D games and related research. Consistency maintenance algorithms are shown to exist in a usability trade-off space. A set of usability metrics is introduced and used to experimentally explore this space. Our results imply that no single algorithm is suitable for every in-game situation. The thesis concludes with an informal evaluation of the AMP based on our experience using the Fiaa.NET as an AMP framework. We found that AMP had several weaknesses, but that these were outweighed by the benefits for the developer. / Thesis (Master, Computing) -- Queen's University, 2008-01-14 23:11:30.657

Software clones are considered harmful in software maintenance and evolution. However, despite a decade of active research, there is a marked lack of work in the detection and analysis of near-miss software clones, those where minor to extensive modifications have been made to the copied fragments. In this thesis, we advance the state-of-the-art in clone detection and analysis in several ways. First, we develop a hybrid clone detection method, called NICAD, that can detect both exact and near-miss clones with high precision and recall and with reasonable performance. Second, in order to address the decade of vagueness in clone definition, we propose an editing taxonomy for clone creation that models developers' editing activities in the copy/pasted code in a top-down fashion. NICAD is designed to address the different types of clones in the editing taxonomy. Third, we have conducted a scenario-based qualitative comparison and evaluation of all of the currently available clone detection techniques and tools in the context of a unified conceptual framework. Using the results of this study one can more easily choose the right tools to meet the requirements and constraints of any particular application, and can identify opportunities for hybridizing different techniques. The hybrid architecture of NICAD was derived from this study. Fourth, in order to evaluate and compare the available tools in a realistic setting and to avoid the challenges and huge manual effort in validating candidate clones, we have developed a mutation-based framework that automatically and efficiently measures (and compares) the recall and precision of clone detection tools for different fine-grained clone types of the proposed editing taxonomy. We have evaluated NICAD using this framework and found that it is capable of detecting different types of clones with high precision and recall. Finally, we have conducted a large scale empirical study of cloning in open source systems, both to evaluate NICAD and to study the cloning characteristics of these systems in several different dimensions. The study has demonstrated that NICAD is capable of accurately finding both exact and near-miss function clones even in large systems and different languages, and that there seem to be a large number of clones in those systems. / Thesis (Ph.D, Computing) -- Queen's University, 2009-08-31 14:05:30.233

Software clones are considered harmful in software maintenance and evolution. However, despite a decade of active research, there is a marked lack of work in the detection and analysis of near-miss software clones, those where minor to extensive modifications have been made to the copied fragments. In this thesis, we advance the state-of-the-art in clone detection and analysis in several ways. First, we develop a hybrid clone detection method, called NICAD, that can detect both exact and near-miss clones with high precision and recall and with reasonable performance. Second, in order to address the decade of vagueness in clone definition, we propose an editing taxonomy for clone creation that models developers' editing activities in the copy/pasted code in a top-down fashion. NICAD is designed to address the different types of clones in the editing taxonomy. Third, we have conducted a scenario-based qualitative comparison and evaluation of all of the currently available clone detection techniques and tools in the context of a unified conceptual framework. Using the results of this study one can more easily choose the right tools to meet the requirements and constraints of any particular application, and can identify opportunities for hybridizing different techniques. The hybrid architecture of NICAD was derived from this study. Fourth, in order to evaluate and compare the available tools in a realistic setting and to avoid the challenges and huge manual effort in validating candidate clones, we have developed a mutation-based framework that automatically and efficiently measures (and compares) the recall and precision of clone detection tools for different fine-grained clone types of the proposed editing taxonomy. We have evaluated NICAD using this framework and found that it is capable of detecting different types of clones with high precision and recall. Finally, we have conducted a large scale empirical study of cloning in open source systems, both to evaluate NICAD and to study the cloning characteristics of these systems in several different dimensions. The study has demonstrated that NICAD is capable of accurately finding both exact and near-miss function clones even in large systems and different languages, and that there seem to be a large number of clones in those systems. / Thesis (Ph.D, Computing) -- Queen's University, 2009-08-31 14:05:30.233

Software systems continue to play an increasingly important role in our daily lives, making the quality of software systems an extremely important issue. Therefore, a significant amount of recent research focused on the prioritization of software quality assurance efforts. One line of work that has been receiving an increasing amount of attention is Software Defect Prediction (SDP), where predictions are made to determine where future defects might appear. Our survey showed that in the past decade, more than 100 papers were published on SDP. Nevertheless, the adoption of SDP in practice to date is limited. In this thesis, we survey the state-of-the-art in SDP in order to identify the challenges that hinder the adoption of SDP in practice. These challenges include the fact that the majority of SDP research rarely considers the impact of defects when performing their predictions, seldom provides guidance on how to use the SDP results, and is too reactive and defect-centric in nature. We propose approaches that tackle these challenges. First, we present approaches that predict high-impact defects. Our approaches illustrate how SDP research can be tailored to consider the impact of defects when making their predictions. Second, we present approaches that simplify SDP models so they can be easily understood and illustrates how these simple models can be used to assist practitioners in prioritizing the creation of unit tests in large software systems. These approaches illustrate how SDP research can provide guidance to practitioners using SDP. Then, we argue that organizations are interested in proactive risk management, which covers more than just defects. For example, risky changes may not introduce defects but they could delay the release of projects. Therefore, we present an approach that predicts risky changes, illustrating how SDP can be more encompassing (i.e., by predicting risk, not only defects) and proactive (i.e., by predicting changes before they are incorporated into the code base). The presented approaches are empirically validated using data from several large open source and commercial software systems. The presented research highlights how challenges of pragmatic SDP can be tackled, making SDP research more beneficial and applicable in practice. / Thesis (Ph.D, Computing) -- Queen's University, 2012-08-02 13:12:39.707

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No abstract available. / Thesis (Ph.D.)-University of Natal, Durban, 1983.

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