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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.
111

Beyond the high road : a scenario analysis of the prospects for political stability or instability in South Africa over the period to 2024 / Frans Johannes Cornelius Cronje

Cronje, Frans Johannes Cornelius January 2013 (has links)
Despite the widely hailed success of South Africa’s transition from apartheid to democracy it was apparent by the mid-2000s that beneath the veneer of stability lay a country facing serious social and economic challenges. The employment and labour market participation rates were uniquely low among emerging markets. Protest action against the state had reached levels last encountered in the volatile 1980s and early 1990s. The budget and current account deficits had reached unsustainable levels. By its own admission the government realised that the country was not recording GDP growth rates necessary to make dramatic inroads into poverty, unemployment and inequality levels. A number of analysts and commentators therefore came to question the future stability of South Africa’s political system. Trade unions and some Cabinet ministers routinely described unemployment as a “ticking time bomb”. The Chairman of the Institute of International Affairs wrote in Business Day that he could predict when South Africa’s “Tunisia Day” would arrive. The respected Economist newspaper ran a front page feature on what it called South Africa’s “downhill slide”. Former President FW de Klerk warned that South Africa was approaching a precipice. Clem Sunter, South Africa’s most renowned scenario planner, upped his prospects that South Africa may become a failed state. Global ratings agencies downgraded South Africa citing the fear that government policy could not meet popular demands. Amidst such speculation it is vitally important that the prospects for instability be investigated and determined, not via opinion or speculation, but rather against a sound body of theory. This task is complicated by the fact that the feared instability may only occur at a point in the future. The theory must therefore be applied via a methodology capable of overcoming the weak track record of political science in accurately anticipating major shifts in political systems. This problem statement will be addressed by showing that complex systems theory holds the key to a series of units of analysis via which the stability or instability of any political system can be objectively determined, compared to any other political system, and tracked over time. Secondly that there are scenario planning methodologies that can overcome the uncertainty inherent in the futures of all complex systems and thereby the poor track record that political scientists have in anticipating dramatic future changes in the systems they study. When combined into a single complex systems/scenario model, these theoretical and methodological points of departure will allow the long term prospects for stability or instability of any political system to be accurately and objectively determined. / PhD (Development and Management) North-West University, Potchefstroom Campus, 2013
112

Beyond the high road : a scenario analysis of the prospects for political stability or instability in South Africa over the period to 2024 / Frans Johannes Cornelius Cronje

Cronje, Frans Johannes Cornelius January 2013 (has links)
Despite the widely hailed success of South Africa’s transition from apartheid to democracy it was apparent by the mid-2000s that beneath the veneer of stability lay a country facing serious social and economic challenges. The employment and labour market participation rates were uniquely low among emerging markets. Protest action against the state had reached levels last encountered in the volatile 1980s and early 1990s. The budget and current account deficits had reached unsustainable levels. By its own admission the government realised that the country was not recording GDP growth rates necessary to make dramatic inroads into poverty, unemployment and inequality levels. A number of analysts and commentators therefore came to question the future stability of South Africa’s political system. Trade unions and some Cabinet ministers routinely described unemployment as a “ticking time bomb”. The Chairman of the Institute of International Affairs wrote in Business Day that he could predict when South Africa’s “Tunisia Day” would arrive. The respected Economist newspaper ran a front page feature on what it called South Africa’s “downhill slide”. Former President FW de Klerk warned that South Africa was approaching a precipice. Clem Sunter, South Africa’s most renowned scenario planner, upped his prospects that South Africa may become a failed state. Global ratings agencies downgraded South Africa citing the fear that government policy could not meet popular demands. Amidst such speculation it is vitally important that the prospects for instability be investigated and determined, not via opinion or speculation, but rather against a sound body of theory. This task is complicated by the fact that the feared instability may only occur at a point in the future. The theory must therefore be applied via a methodology capable of overcoming the weak track record of political science in accurately anticipating major shifts in political systems. This problem statement will be addressed by showing that complex systems theory holds the key to a series of units of analysis via which the stability or instability of any political system can be objectively determined, compared to any other political system, and tracked over time. Secondly that there are scenario planning methodologies that can overcome the uncertainty inherent in the futures of all complex systems and thereby the poor track record that political scientists have in anticipating dramatic future changes in the systems they study. When combined into a single complex systems/scenario model, these theoretical and methodological points of departure will allow the long term prospects for stability or instability of any political system to be accurately and objectively determined. / PhD (Development and Management) North-West University, Potchefstroom Campus, 2013
113

Improving the Management of Controllers’ Interruptions through the Working Awareness Interruption Tool: WAIT

Alqahtani, Meshael January 2014 (has links)
Interruptions in time-critical, dynamic, and collaborative environments, such as air traffic control (ATC), can provide valuable, task-relevant information. However, they also negatively impact task performance by distracting the operator from on-going tasks and consuming attention resources. This thesis develops and assesses a tool to assist radar air traffic controllers in managing interruptions. Field observations and interviews with air traffic controllers were utilized to develop an understanding of how interruptions occur in real ATC environments, and to identify where opportunities exist to use technology to support the interruption management process. It was identified that operators in these environments could better manage the effects of interruptions if there were indications to one operator of the availability of a collaborator and the urgency of an interruption from a collaborator. Present communication systems do not facilitate the awareness of these functionalities. An initial prototype for providing these functionalities in operational ATC displays was designed. Feedback on the prototypes was solicited through Participatory Design (PD) sessions with air traffic controllers. Based on the refinement of these prototypes, the Working Awareness Interruption Tool (WAIT) was developed to support more efficient and appropriate interruption timing in the context of complex, real-time, distributed, human operator interactions. Variations of the tool demonstrated several ways of showing the availability of the controller to be interrupted (either through manual settings or automatic detection) as well as incorporating a means of conveying the urgency level of the interruption. In order to examine the utility of the tool and to assess the importance and validity of its features, an experiment was conducted in a laboratory-based setting. The results of the experiment show the potential of this tool in an environment representative of air traffic control tasks and communication. Although the sample size was limited, the WAIT facilitated improved performance on both objective measures and self-reported measures, and reduced the distraction effects of interruptions from other operators. These improvements occurred without affecting perceptions of the effectiveness of communications. Questionnaire and interview results showed that participants appear to prefer an automated setting of availability to be shown to other collaborators. Identifying two examples of key features supporting interruption management (communicating availability and urgency) in air traffic control is one of the key contributions of this work. The work also makes a contribution by demonstrating that providing a tool incorporating these features can improve performance in an environment representative of ATC, albeit with naïve participants. Finally, the research makes a contribution by presenting the challenges associated with evaluating interruption management tools that require collaboration between operators in a system.
114

Towards decision support for complex system architecture design with innovation integration in early design stages

Moullec, Marie-Lise 24 January 2014 (has links) (PDF)
The aim of this research work is to propose a method allowing innovation integration in early design stages and supporting architecture design of complex systems that have significant implications for the rest of overall system life-cycle. Focusing on system architectures generation support, this method proposes to use Bayesian networks combined with Constraint Satisfaction Problem (CSP) techniques in order to semi-automatically generate and evaluate complex systems architectures. Bayesian network model is used to represent the design problem in terms of decision variables, constraints and performances. Furthermore, an architecture generation algorithm is proposed to generate feasible solutions and to cluster them with regard to a given confidence level threshold. This confidence level is representing the estimation of the uncertainty on the overall system. Estimation of architecture performances are also calculated within the Bayesian network. Once the system architectures are generated, a CSP model optimises the component placement regarding placement constraints and optimisation objectives defined by designers. Software has been developed for the purpose of problem modelling and solutions visualisation. Two industrial implementations yielded in a generation of a high number of architecture solutions. In order to test the feasibility of architecture selection in an industrial environment, a study was conducted integrating four system designers. This study underlined the difficulties in defining architecture selection criteria and provides recommendations for the future system architecture selection support.
115

Variability Monitoring for Clinical Applications

Bravi, Andrea 15 May 2014 (has links)
Current monitoring tools in the intensive care units focus on displaying physiologically monitored parameters (e.g. vital signs such as heart rate, respiratory rate and blood pressure) at the present moment. Added clinical utility can be found by analyzing how the conditions of a patient evolve with time, and automatically relating that dynamics to population trends. Variability analysis consists of monitoring patterns of variation over intervals in time of physiological signals such as heart rate and respiratory rate. Given that illness has been associated in multiple studies with altered variability, most commonly lack of variation, variability monitoring represents a tool whose contribution at the bedside still needs to be explored. With the long term objective of improving care, this thesis promotes the use of variability analysis through three distinct types of analysis: facing the technical challenges involved with the dimensionality of variability analysis, enhancing the physiological understanding of variability, and showing its utility in real world clinical applications. In particular, the contributions of this thesis include: the review and classification into domains of a large array of measures of variability; the design of system and methods to integrate multiple measures of variability into a unique score, called composite measure, bringing relevant information to specific clinical problems; the comparison of patterns of heart rate variability during exercise and sepsis development, showing the inability of single measures of variability to discriminate between the two kinds of stressors; the analysis of variability produced from a physiologically-based model of the cardiovascular system, showing that each single measure of variability is an unspecific sensor of the body, thereby promoting multivariate analysis to the only means of understanding the physiology underlying variability; the study of heart rate variability in a population at high risk of sepsis development, showing the ability of variability to predict the occurrence of sepsis more than 48 hours in advance respect to the time of diagnosis of the clinical team; the study of heart and respiratory rate variability in intubated intensive care unit patients, showing how variability can provide a better way of assessing extubation readiness respect to commonly used clinical parameters. Overall, it is hoped that these novel contributions will help promoting bedside applications of variability monitoring to improve patient care.
116

Sustainability assessment of energy systems

Gaudreau, Kyrke 08 May 2013 (has links)
This research project set out to develop and apply a framework for assessing how energy systems may be structured to help society progress towards sustainability. The general intent was to outline a way to decide upon the things that matter in order to make better decisions that will lead to positive near- and long-term outcomes. There are various ways of reaching the goal described above, and the path chosen in this dissertation centred on Gibson’s (2006) sustainability assessment framework, an approach to integrated sustainability-based decision-making. In order to contribute to extending and specifying Gibson’s approach to sustainability assessment for energy undertakings, this project developed a theoretical framework grounded in various forms of complexity and energy. The journey described in the dissertation begins with an exploration of the complexity of science, the subject of Chapter 2. We live in a world characterized by inherent uncertainty, multiple worldviews, conflicting values, power dynamics and a whole host of other challenges to science and decision-making. Many of the environmental and human challenges we currently face have arisen in part because we do not sufficiently respect the limits to knowledge and the personal biases we all bring to the table. Chapter 2 develops a framework for knowledge generation and decision-making situated within its social context, and operationalizes this framework through the process of criteria specification. Drawing from multiple sources of data – particularly documentary analysis, semi-structured interviews and observation – the criteria specification cycle provided the means of and determining and deciding upon the things that matter in a given case and context. The complexity of science is only half the story emerging from the complex systems literature. From a different perspective, it is evident that we live in a world of complex dynamics and interconnections, and it is important to ensure that whatever energy paths we set out on recognize these dynamics. Fortunately, there is a wide range of literature relating to the characteristics of complex systems in general, as well as their energy and material flows in societies. These literatures are explored in Chapter 3 to develop an understanding of and guidelines for managing complex systems to the extent possible and appropriate. Building on the theory developed in Chapters 2 and 3, the discussion in Chapter 4 began to develop an understanding of energy systems and energy decision-making and was structured around three general questions: (1) what is the energy problem? (2) what are the characteristics of an appropriate and constructive relationship with energy? and (3) how can the necessary and desired sociotechnical systems changes be achieved. These questions were largely addressed through an exploration of the soft energy path and transition management and led to two sets of guidelines designed to address energy systems structure and change. The theoretical framework developed over Chapters 2-4 was consolidated into a proposed set of sustainability criteria for energy undertakings. The sustainability criteria set represents the principal theoretical contribution of the dissertation to the academy and the broader assessment community, and outlines a suite of generally desirable system attributes and actions for achieving progress towards sustainability, as opposed to an acceptability threshold. The proposed sustainability criteria are primarily intended for application regarding energy undertakings at a wide variety of scales, but are much more broadly relevant. In a manner that is more iterative than can be described in this abstract, the sustainability assessment framework described in this dissertation was applied in, and enriched through, four distinct case studies that assessed (1) the 2006 Ontario Integrated Power Systems Plan proposed by the Ontario Power Authority. The Integrated Power Systems Plan was originally framed as a coal versus nuclear problem, as opposed to a critical appraisal of power systems planning; and in doing so it underplayed potential for conservation, demand management, increased renewable energy, and social change; (2) a small-scale biodiesel operation in Barbados. The plant owner collected used cooking oil from restaurants, roadside stands, and individual homes, and converted it into biodiesel using a first-generation processing technology known as transesterification. (3) a sugarcane-ethanol plant in the Tietê-Jacaré Watershed of São Paulo, Brazil. The sugarcane ethanol mill harvests approximately 21,000 hectares of sugarcane crops from seven municipalities and produces hydrated ethanol for domestic markets, and sugar for domestic and international markets; and (4) the agricultural and energy systems in Senegal. Senegal suffers from significant deforestation and soil fertility decline coupled with demographic change. The many interconnections between the energy and agricultural systems require an integrated assessment of both. Each individual case study stands alone in providing novel insights emerging from application of the framework in the particular case and context. At the more general level, five important insights emerged from the case studies, including: (1) the benefits of, and need for, maintaining a flexible unit of analysis so as to improve problem structuring; (2) the importance of grounding an assessment within its context; (3) the benefits of seeking integration and positive indirect effects; (4), the need to plan for and develop energy bridges towards feasible and desirable energy futures; and (5), the need for caution in the face of thresholds and uncertainty. The individual and general insights from the case studies were incorporated into the most recent version of the sustainability assessment framework described in this dissertation. The framework is suitable for application, with specification for particular case and context, to all types of energy systems at all scales.
117

Conceptualizing complex meaning systems : the case of management fads

Corfield, Wendy Lea January 2006 (has links)
The thesis is an attempt to apply complex systems thinking to the problem of meaning. It is in two parts. Part 1, Chapter 1 introduces the research agenda and overviews the thesis. Chapter 2 establishes the value of adopting a systems approach to the problem of meaning. The next chapter introduces key concepts of complex systems theory as they apply to sociocultural phenomena, and the last chapter in Part 1 reviews three theories of complex meaning systems (Donald Campbell, Jay Lemke, and Paul Cilliers) from which a preliminary model and agenda for theorising complex meaning systems is proposed. Part 2 of the thesis investigates the phenomena of management fads, applying the models of complex meaning systems formulated in Part 1. No primary empirical work is attempted; rather an analytical engagement is conducted using secondary literature on what we know about such fads. The literature, both primary and secondary, is reviewed and critiqued. The final chapters exemplify the problem of meaning using the theory building and agenda setting from Part 1. The concluding chapter reflects on the adequacy of a complex systems approach to meaning, critiques the process of the thesis and comments upon its contribution.
118

Towards immunization of complex engineered systems: products, processes and organizations

Efatmaneshnik, Mahmoud, Mechanical & Manufacturing Engineering, Faculty of Engineering, UNSW January 2009 (has links)
Engineering complex systems and New Product Development (NPD) are major challenges for contemporary engineering design and must be studied at three levels of: Products, Processes and Organizations (PPO). The science of complexity indicates that complex systems share a common characteristic: they are robust yet fragile. Complex and large scale systems are robust in the face of many uncertainties and variations; however, they can collapse, when facing certain conditions. This is so since complex systems embody many subtle, intricate and nonlinear interactions. If formal modelling exercises with available computational approaches are not able to assist designers to arrive at accurate predictions, then how can we immunize our large scale and complex systems against sudden catastrophic collapse? This thesis is an investigation into complex product design. We tackle the issue first by introducing a template and/or design methodology for complex product design. This template is an integrated product design scheme which embodies and combines elements of both design theory and organization theory; in particular distributed (spatial and temporal) problem solving and adaptive team formation are brought together. This design methodology harnesses emergence and innovation through the incorporation of massive amount of numerical simulations which determines the problem structure as well as the solution space characteristics. Within the context of this design methodology three design methods based on measures of complexity are presented. Complexity measures generally reflect holistic structural characteristics of systems. At the levels of PPO, correspondingly, the Immunity Index (global modal robustness) as an objective function for solutions, the real complexity of decompositions, and the cognitive complexity of a design system are introduced These three measures are helpful in immunizing the complex PPO from chaos and catastrophic failure. In the end, a conceptual decision support system (DSS) for complex NPD based on the presented design template and the complexity measures is introduced. This support system (IMMUNE) is represented by a Multi Agent Blackboard System, and has the dual characteristic of the distributed problem solving environments and yet reflecting the centralized viewpoint to process monitoring. In other words IMMUNE advocates autonomous problem solving (design) agents that is the necessary attribute of innovative design organizations and/or innovation networks; and at the same time it promotes coherence in the design system that is usually seen in centralized systems.
119

Advanced Methodologies for Power System Security and Vulnerability Analysis

Guo Chen Unknown Date (has links)
Nowadays, with the rapid expansion of increasing utilization of renewable energy sources, power grid is evolving into a much complex man-made system in the technological age. Under the new circumstances, traditional methodologies for power system security analysis are facing a serious challenge. For the past decade, many countries have experienced large blackouts, which expose potential problems of current models and methodologies in power industry. On the other hand, since the 9.11 event and frequent suicide bombing attacks in some countries, terrorism has become a major threat for national security. With the extensive growth of terrorism activities, power system, the significant critical infrastructure, probably becomes the target of terrorists. If this happens, the impact is dramatically severe and may yield more frequent blackouts. This Ph.D. thesis aims at developing some advanced models and methodologies for exploring the vulnerability of power system and protecting it against potential terrorism threat. The dissertation mainly consists of the following four parts. (1)Complex network theory based power system security and vulnerability analysis methodologies are introduced. Mathematically, an interconnected complex power grid can be described as a complex network of nodes connected by edges. Generally speaking, topology parameters of network structure include important information of the structure. That is to say, some critical nodes and lines can have significant impact on large-scale blackouts. The thesis will present a new methodology to recognize those critical nodes and lines in power grids. (2)Complex system theory based power grid security and vulnerability analysis methodologies are presented. Power grid is a complex dynamic evolutionary system over years with continuous expansion so as to underpin the ongoing increase of power demand. Some properties of complex systems may have important relationship with large-scale blackouts. In other words, there may be some stages of evolutionary power systems that would be more likely to cause large blackouts. The thesis will investigate the relationship to identify those critical stages of power grids. (3)Game theory is applied to methodologies for power system security and vulnerability analysis. Terrorists are often considered as fully intelligent and strategic actors who can even hire scientists and power engineers to seek the vulnerability of power systems and then launch a vital attack. Game theory does treat actors as fully strategic players and has been successfully applied to many disciplines including economics, political science and military. The thesis will present new models and analysis methods for protecting power systems under terrorism attacks. (4)Cyber security technology is considered in power system security and vulnerability analysis. It is known that information technology plays an import role in today and next generation grid. In this situation, cyber security should be an important issue. If it is vulnerable to malicious threats such as hackers and cyber-terrorists, power grid will not reach its full capabilities. The thesis will present an initial framework to reduce the vulnerability of power grid against potential cyber attack.
120

Advanced Methodologies for Power System Security and Vulnerability Analysis

Guo Chen Unknown Date (has links)
Nowadays, with the rapid expansion of increasing utilization of renewable energy sources, power grid is evolving into a much complex man-made system in the technological age. Under the new circumstances, traditional methodologies for power system security analysis are facing a serious challenge. For the past decade, many countries have experienced large blackouts, which expose potential problems of current models and methodologies in power industry. On the other hand, since the 9.11 event and frequent suicide bombing attacks in some countries, terrorism has become a major threat for national security. With the extensive growth of terrorism activities, power system, the significant critical infrastructure, probably becomes the target of terrorists. If this happens, the impact is dramatically severe and may yield more frequent blackouts. This Ph.D. thesis aims at developing some advanced models and methodologies for exploring the vulnerability of power system and protecting it against potential terrorism threat. The dissertation mainly consists of the following four parts. (1)Complex network theory based power system security and vulnerability analysis methodologies are introduced. Mathematically, an interconnected complex power grid can be described as a complex network of nodes connected by edges. Generally speaking, topology parameters of network structure include important information of the structure. That is to say, some critical nodes and lines can have significant impact on large-scale blackouts. The thesis will present a new methodology to recognize those critical nodes and lines in power grids. (2)Complex system theory based power grid security and vulnerability analysis methodologies are presented. Power grid is a complex dynamic evolutionary system over years with continuous expansion so as to underpin the ongoing increase of power demand. Some properties of complex systems may have important relationship with large-scale blackouts. In other words, there may be some stages of evolutionary power systems that would be more likely to cause large blackouts. The thesis will investigate the relationship to identify those critical stages of power grids. (3)Game theory is applied to methodologies for power system security and vulnerability analysis. Terrorists are often considered as fully intelligent and strategic actors who can even hire scientists and power engineers to seek the vulnerability of power systems and then launch a vital attack. Game theory does treat actors as fully strategic players and has been successfully applied to many disciplines including economics, political science and military. The thesis will present new models and analysis methods for protecting power systems under terrorism attacks. (4)Cyber security technology is considered in power system security and vulnerability analysis. It is known that information technology plays an import role in today and next generation grid. In this situation, cyber security should be an important issue. If it is vulnerable to malicious threats such as hackers and cyber-terrorists, power grid will not reach its full capabilities. The thesis will present an initial framework to reduce the vulnerability of power grid against potential cyber attack.

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