Decision support continuum paradigm for cardiovascular disease: Towards personalized predictive models

Clinical decision making is a ubiquitous and frequent task physicians make in their daily clinical practice. Conventionally, physicians adopt a cognitive predictive modelling process (i.e. knowledge and experience learnt from past lecture, research, literature, patients, etc.) for anticipating or ascertaining clinical problems based on clinical risk factors that they deemed to be most salient. However, with the inundation of health data and the confounding characteristics of diseases, more effective clinical prediction approaches are required to address these challenges. Approximately a few century ago, the first major transformation of medical practice took place as science-based approaches emerged with compelling results. Now, in the 21st century, new advances in science will once again transform healthcare. Data science has been postulated as an important component in this healthcare reform and has received escalating interests for its potential for ‘personalizing’ medicine. The key advantages of having personalized medicine include, but not limited to, (1) more effective methods for disease prevention, management and treatment, (2) improved accuracy for clinical diagnosis and prognosis, (3) provide patient-oriented personal health plan, and (4) cost containment. In view of the paramount importance of personalized predictive models, this thesis proposes 2 novel learning algorithms (i.e. an immune-inspired algorithm called the Evolutionary Data-Conscious Artificial Immune Recognition System, and a neural-inspired algorithm called the Artificial Neural Cell System for classification) and 3 continuum-based paradigms (i.e. biological, time and age continuum) for enhancing clinical prediction. Cardiovascular disease has been selected as the disease under investigation as it is an epidemic and major health concern in today’s world. We believe that our work has a meaningful and significant impact to the development of future healthcare system and we look forward to the wide adoption of advanced medical technologies by all care centres in the near future.Open Acces

On Fault Tolerance Methods for Networks-on-Chip

Technology scaling has proceeded into dimensions in which the reliability of manufactured devices is becoming endangered. The reliability decrease is a consequence of physical limitations, relative increase of variations, and decreasing noise margins, among others. A promising solution for bringing the reliability of circuits back to a desired level is the use of design methods which introduce tolerance against possible faults in an integrated circuit. This thesis studies and presents fault tolerance methods for network-onchip (NoC) which is a design paradigm targeted for very large systems-onchip. In a NoC resources, such as processors and memories, are connected to a communication network; comparable to the Internet. Fault tolerance in such a system can be achieved at many abstraction levels. The thesis studies the origin of faults in modern technologies and explains the classification to transient, intermittent and permanent faults. A survey of fault tolerance methods is presented to demonstrate the diversity of available methods. Networks-on-chip are approached by exploring their main design choices: the selection of a topology, routing protocol, and flow control method. Fault tolerance methods for NoCs are studied at different layers of the OSI reference model. The data link layer provides a reliable communication link over a physical channel. Error control coding is an efficient fault tolerance method especially against transient faults at this abstraction level. Error control coding methods suitable for on-chip communication are studied and their implementations presented. Error control coding loses its effectiveness in the presence of intermittent and permanent faults. Therefore, other solutions against them are presented. The introduction of spare wires and split transmissions are shown to provide good tolerance against intermittent and permanent errors and their combination to error control coding is illustrated. At the network layer positioned above the data link layer, fault tolerance can be achieved with the design of fault tolerant network topologies and routing algorithms. Both of these approaches are presented in the thesis together with realizations in the both categories. The thesis concludes that an optimal fault tolerance solution contains carefully co-designed elements from different abstraction levelsSiirretty Doriast

Generalization of Computer-Assisted Attention Training for Children with Attention Deficit Disorder

Psycholog

Competition in the tridimensional urban fresh produce retail market : the case of the Tshwane metropolitan area, South Africa

A few vertically integrated retail chains increasingly dominate South Africa’s agro-food supply chain. M+M Planet Retail (2004) placed the market concentration among retailers to be as high as 96% for the top four chains leaving only 4% to the small competitors. The onset of this trend has led to the demise of a large number of “mom and pop” general dealers in favour of the sleek new stores as they were either priced or bought out of business. Players in the fresh produce market have proved to be resilient to this onslaught. The green grocers and hawkers have survived the “category killers” and appear to be able to face this competition head on. It is this resilience that is of interest to this study. The review of literature revealed a dearth of studies and hence methodology into the nature of the interaction between the three forms of retail. A preliminary survey also revealed the lack of coherent and detailed information, particularly among the greengrocers and hawkers. Thus the established methods of modelling competition analysis, namely the Structure Conduct Performance and the New Empirical Industrial Organisation frameworks, were deemed inappropriate. The study therefore took an exploratory form that relied on measures of central tendency and the perceptions of leading industry practitioners to reveal the nature and magnitude of competition between supermarkets, green grocers and hawkers. The study primarily drew on ‘Porter’s forces’ competition model to structure the investigation. It also employed a chain analysis approach including supply and value chain analysis (VCA) tools to analyse this competition. The study therefore sought to unpack the retail sections of the three chains in terms of identifying role-players; their relationships and interaction; as well as to account for the relative values that different types of fresh produce retailers generated for the final consumer. Besides the contribution to the general body of knowledge about the nature of the system that feeds us, this study provides means for the competing channels to upgrade and improve efficiency. A developmental and empowerment point of view was emphasised in the research, as such, identifying possible measures to upgrade and improve the informal sector was given precedence. The objective was to describe and analyse the competitive environment in which FFV was retailed in the Tshwane through a determination of the competitive and strategic behaviour of retailers and a mapping the flow of value. It was hypothesised that fresh produce retailers competed by varying elements of their marketing mix to suit their niche markets. The investigation was conducted in two phases; a pilot study followed by a survey involving a six-step sampling frame targeting a total of 120 respondents including 15 supermarkets, 30 greengrocers and 75 hawkers. This analysis was limited to the bounds of the Tshwane metropolitan area, South Africa, and focused on six fresh fruits and vegetable lines concurrently traded by supermarkets, greengrocers and hawkers. The main findings of the investigation include that tri-dimensional FFV retail competition was most intense in the middle-income areas of the city. The low income areas were dominated by informal traders while the large supermarkets chains and the large format greengrocers dominated the high income areas. The non-syndicated greengrocers were confined to the middle-income areas where competition was most intense. When the marketing strategies and chain maps were compared it was concluded that the tridimensional competitive environment was facilitated by the existence of multiple niches; the equalising effect of produce market based pricing; the general upgrade in product quality offered by all retailers; characteristics of fresh produce itself as compared to other foodstuffs and the existence of multiple market niches in the sector. Concluding the study were recommendations to improve (upgrade) the marketing performance of each of the three channels.Dissertation (MSc(Agric) (Agricultural Economics))--University of Pretoria, 2007.Agricultural Economics, Extension and Rural DevelopmentMSc(Agric)unrestricte

An investigation of excessive reassurance seeking in OCD

Excessive reassurance-seeking (ERS) is a common problem among individuals dealing with emotional and/or psychological difficulties. Prior research on ERS has focused almost exclusively on the potential consequences of this behaviour in the contexts of Depression and Hypochondriasis, and this research has shown that ERS contributes to interpersonal difficulties and emotional distress. Despite anecdotal evidence that ERS is a hallmark feature of Obsessive-Compulsive Disorder (OCD), comparatively few studies have examined OCD-related ERS. The goal of the present research was to examine various cognitive, behavioural and affective processes that may be involved in the perpetuation of ERS, specifically within the contexts of OCD and Depression. Given the purported functional equivalence between OCD-related reassurance seeking and compulsive checking (Rachman, 2002), the current investigations also aimed to compare ERS and repeated checking activity across a number of important domains (i.e., content, precipitating factors, function and termination criteria). Toward these goals, Study I employed a semi-structured interview with clinical (OCD and Depression) and non-clinical individuals to examine factors involved in the onset, maintenance and termination of ERS and repeated checking. Results revealed that individuals with OCD tend to seek reassurance about perceived general threats (e.g., fire, theft), whereas ERS tends to be focused on perceived social threats (e.g., abandonment, loss of support) among depressed individuals. Clinical participants reported greater anxiety, sadness and perceived threat in association with ERS and repeated checking than healthy control participants. Study 2 examined how manipulations of threat, responsibility, and ambiguity of feedback impacted upon non-clinical participants' anxiety and compulsive urges (to seek reassurance and to check) in a series of experimental vignettes. Consistent with hypotheses, higher levels of perceived threat, responsibility and ambiguity of feedback were associated with greater anxiety and compulsive urges. Results also suggested that perceived threat and responsibility partially mediated the effects of ambiguity of feedback on anxiety, urges to check, and (for threat) urges to seek reassurance. The collective results of these studies are discussed in terms of cognitive and behavioural models of OCD, and directions for future research are suggested

The Habitus of Mackenzie King: Canadian Artists, Cultural Capital and the Struggle for Power

This dissertation analyzes the struggle between William Lyon Mackenzie King, Canada’s longest-serving Prime Minister (1922-1930, 1935-1948), and Canadian artists to define and determine the nature and distribution of arts and culture in Canada prior to the 1949 Royal Commission on National Development in the Arts, Letters and Sciences. Using Pierre Bourdieu’s theories of habitus, “fields” of knowledge and power, and religious, social and cultural capital, the dissertation analyzes the central paradox of why—despite his decades-long involvement in half-a-dozen artistic disciplines—King failed to implement cultural policies as Prime Minister that would have benefited Canadian artists and the arts and culture in Canada. The dissertation applies Pierre Bourdieu’s model of social change in which “priests” with conservation strategies and charismatic “prophets” with subversion strategies compete among the “laity” for consumers of their respective symbolic goods to document how artists organized locally and nationally to accumulate social, cultural and political capital in their attempt to compel the federal government to implement their cultural objectives—state support for the arts. The dissertation posits that Mackenzie King’s inability to control his sexual impulses led him to espouse a conception of art whose primary function was to project Christian character and ideals. By establishing King’s religious and sexual habiti, I am able to show why he felt compelled to project such an idealized characterization in works of art depicting himself, members of his family, and public figures whose service to the nation he felt should be emulated by Canadians. As Leader of the Liberal Party, Leader of the Opposition in Parliament and as Prime Minister, King was able to use his political and economic power in the political field over three decades (1919-1948) to define who was a real artist and who was not, what constituted artistic legitimacy and what was the artistic and economic value of Canadian cultural production. The dissertation suggests that the analysis of King’s relationship with the arts and artists provides the key to unlocking the enigma of Mackenzie King and that in the struggle between artists and the Prime Minister over the nature and distribution of arts and culture in Canada, the artists won

The development of design strategies that promote the engagement of users in the authorship process

Underlying all the ideas articulated in this thesis is a political challenge to the designer's innate right to occupy a hierarchical position in the designer/user relationship. Equally, where these relationships have been superseded (in for example Desktop Publishing and web page design) the designer still has an important, but quite different, role to play. In contrast to some community design-led initiatives, the aim here is not necessarily to welcome users into an aspect of the conventional design process on terms determined by the designer by helping users conform to practices established by the designer. The aim is the development of strategies in which the designer and user can influence each other without dominating, going beyond conventional strategies of consultancy or feedback. My determination is not to turn everyday users into mouthpieces of surrogate design sensibility, in the way that 'makeover' TV programs, and their DIY predecessors, promote a particular aesthetic as good design, leading to a rejection of direct communication between designer and user. This places the designer in a position of power; users will skew their responses towards what they think the designer is looking for. Also designers could never work so inexpensively as to engage in bespoke design activity for more than a fraction of the population. This view has been achieved through the interplay of my own design practice and a spectrum of theoretical (broadly post-structural) influences, although most individuals referenced here would reject this (or any category), including Derrida, Deleuze and Guattari, and the Situationists. My responses to these ideas influence and are influenced by the production of a range of design proposals, and the promotion of the colonisation, modification and even hijacking by others, including designers, users and educators. These have developed in a number of phases: 1 Modular/Adaptive proposals for office furniture, and product design; 2 CAD/CAM proposals in which users select and modify 'design methods' to help them exploit the more technical expert systems available to help them create their own artefacts; 3 Flexible communication systems, which are designs populated and modified by users in ways beyond the control or knowledge of the designer. These stages show an evolution in my creative responses from producing designed artefacts that promote interaction with users, to systems in which the designer and user have to contribute jointly for the systems to function. It is organic, uncontrolled development by the user that determines the development and configuration of these systems guided by the initial conditions and processes determined by the designer. This allows the interreIationship of designers and truly user-led creative activities

FEATURE EXTRACTION AND CLASSIFICATION THROUGH ENTROPY MEASURES

Entropy is a universal concept that represents the uncertainty of a series of random events. The notion \u201centropy" is differently understood in different disciplines. In physics, it represents the thermodynamical state variable; in statistics it measures the degree of disorder. On the other hand, in computer science, it is used as a powerful tool for measuring the regularity (or complexity) in signals or time series. In this work, we have studied entropy based features in the context of signal processing. The purpose of feature extraction is to select the relevant features from an entity. The type of features depends on the signal characteristics and classification purpose. Many real world signals are nonlinear and nonstationary and they contain information that cannot be described by time and frequency domain parameters, instead they might be described well by entropy. However, in practice, estimation of entropy suffers from some limitations and is highly dependent on series length. To reduce this dependence, we have proposed parametric estimation of various entropy indices and have derived analytical expressions (when possible) as well. Then we have studied the feasibility of parametric estimations of entropy measures on both synthetic and real signals. The entropy based features have been finally employed for classification problems related to clinical applications, activity recognition, and handwritten character recognition. Thus, from a methodological point of view our study deals with feature extraction, machine learning, and classification methods. The different versions of entropy measures are found in the literature for signals analysis. Among them, approximate entropy (ApEn), sample entropy (SampEn) followed by corrected conditional entropy (CcEn) are mostly used for physiological signals analysis. Recently, entropy features are used also for image segmentation. A related measure of entropy is Lempel-Ziv complexity (LZC), which measures the complexity of a time-series, signal, or sequences. The estimation of LZC also relies on the series length. In particular, in this study, analytical expressions have been derived for ApEn, SampEn, and CcEn of an auto-regressive (AR) models. It should be mentioned that AR models have been employed for maximum entropy spectral estimation since many years. The feasibility of parametric estimates of these entropy measures have been studied on both synthetic series and real data. In feasibility study, the agreement between numeral estimates of entropy and estimates obtained through a certain number of realizations of the AR model using Montecarlo simulations has been observed. This agreement or disagreement provides information about nonlinearity, nonstationarity, or nonGaussinaity presents in the series. In some classification problems, the probability of agreement or disagreement have been proved as one of the most relevant features. VII After feasibility study of the parametric entropy estimates, the entropy and related measures have been applied in heart rate and arterial blood pressure variability analysis. The use of entropy and related features have been proved more relevant in developing sleep classification, handwritten character recognition, and physical activity recognition systems. The novel methods for feature extraction researched in this thesis give a good classification or recognition accuracy, in many cases superior to the features reported in the literature of concerned application domains, even with less computational costs