Thesis (MPH) --University of Limpopo, 2014 / Topic An investigation of the visual and systemic symptoms experienced by computer users at the National Home Builders’ Registration Council (NHBRC) and British Petroleum (BP) in Johannesburg, Gauteng Province, South Africa. Background The repetitive use of computers in the working places results in the visual and ergonomic disorders that affect the computer users adversely. The computer users experience fatigue which causes visual symptoms such as eyestrain, blurred vision, heaviness of the eyelids or forehead, dry eyes, sensitivity to light and irritatedeyes. The ergonomic disorders like neck pain, backache and wrist pain are also experienced by computer users. These conditions are collectively called Computer Vision Syndrome which is considered as an occupational hazard. Uncorrected refractive errors and binocular anomalies can contribute to these symptoms. The visual and systemic symptoms that affect the computer users in the workplace need to be investigated. Purpose The purpose of the study was to subjectively investigate the visual and systemic symptoms experienced by computer users in the two selected companies in Gauteng Province South Africa. Methodology Structured questions, (open and close ended) were used to obtain information needed for this study. The questions covered demographic as well as information relating to the use of the computer such as the duration of working on computer, the offices/working environment, the appearance and the distance of the screen to the eyes, the working station and visual devices et cetera. Results Participants included 47 (72.3%) females and 17 (26.2%) males and their ages ranged from 20 to 59 years with the mean of 39.5 and the standard deviation of ± 13.1years. Many (80%) of the participants between the ages of 20 to 29 years reported experiencing eye strain. The highest (75%) percentage of slow refocus was reported by the participants that were between the ages of 30 to 39 years. Most males (58.8%) reported experiencing eye strain, slow refocus and headaches associated with computer use. The majority of the females (63.8%) reported experiencing eye strain, while (59.6%) experienced slow refocus and (51.1%) suffered from headaches. A higher percentage of males (23.5%) experienced wrist pain while lower (14.9%) of females experienced wrist pain. No males (0.0%) reported back pain and only a small (8.5%) of females reported back pain. Conclusion Based on the above findings, it is concluded that visual and the systemic symptoms associated with the use of the computer affected most of the workers from the two companies. The factors that may lead to the various symptoms experienced may be ergonomic (environmental) or visual or a combination of these. The environmental factors can be the angle of gaze to the computer screen or the illumination of the working area, while visual factors could be uncorrected refractive error or binocular anomaly. Other factors may include age and working for prolonged time looking at the computer monitor. These factors may then leads to symptoms like eye strain, slow refocus, blurred vision, headaches, dry eyes and systemic symptoms such as neck pain.

Image super-resolution aims to produce a higher resolution representation of a scene from an ensemble of low-resolution images that may be warped, aliased, blurred and degraded by noise. There are a variety of methods for performing super-resolution described in the literature, and in general they consist of three major steps: image registration, fusion and deblurring. This thesis proposes a novel method of performing the first two of these steps. The ultimate aim of image super-resolution is to produce a higher-quality image that is visually clearer, sharper and contains more detail than the individual input images. Machine algorithms can not assess images qualitatively and typically use a quantitative error criterion, often least-squares. This thesis aims to optimise leastsquares directly using a fast method, in particular one that can be implemented using linear filters; hence, a closed-form solution is required. The concepts of optimal interpolation and resampling are derived and demonstrated in practice. Optimal filters optimised on one image are shown to perform nearoptimally on other images, suggesting that common image features, such as stepedges, can be used to optimise a near-optimal filter without requiring the knowledge of the ground-truth output. This leads to the construction of a pulse model, which is used to derive filters for resampling non-uniformly sampled images that result from the fusion of registered input images. An experimental comparison shows that a 10th order pulse model-based filter outperforms a number of methods common in the literature. The use of optimal interpolation for image registration linearises an otherwise nonlinear problem, resulting in a direct solution. Experimental analysis is used to show that optimal interpolation-based registration outperforms a number of existing methods, both iterative and direct, at a range of noise levels and for both heavily aliased images and images with a limited degree of aliasing. The proposed method offers flexibility in terms of the size of the region of support, offering a good trade-off in terms of computational complexity and accuracy of registration. Together, optimal interpolation-based registration and fusion are shown to perform fast, direct and effective super-resolution.

The focus of this study is the phenomenon of beginning teacher competence. In Queensland, the context for the research presented here, the competence of beginning teachers is appraised by their supervisor (usually the principal) at the end of their first year of full-time employment. This appraisal is conducted on behalf of the Queensland Board of Teacher Registration and a positive outcome enables beginning teachers to achieve full teacher registration. Although there exists research suggesting that principals bring to the appraisal process their conceptions of competence, there is a dearth of knowledge about beginning teachers' conceptions of their own teaching competence. The research presented here adds to the debate about competence by including the voice of the beginning teacher. This focus, located within the context of local issues, is used to explore important themes that are relevant to other systems of beginning teacher appraisal. The selection of phenomenography as the research approach adopted for this study is based on its appropriateness to the investigation of a phenomenon such as competence. Phenomenography aims to describe, analyse and understand the ways in which people experience aspects of the world around them. The point of departure that sets apart this approach from many others, is the principle that phenomenography seeks to investigate neither the phenomenon, nor the people who experience the phenomenon, but the relation between the two. The results of a phenomenographic study are presented as a description of all of the possible conceptions that a specific group can have about a particular phenomenon. For the research presented here, eighteen beginning teachers were interviewed individually in order to identify and describe the variation in their conceptions of competence. Research participants representing State, Catholic and Independent school systems were drawn from preschools, special, primary and secondary schools of one provincial city, in one regional area of South East Queensland. Two major outcomes emerged from the research presented here. Firstly, beginning teachers were identified as experiencing competence in a number of ways. Although these conceptions were varied, their number was quite limited. Six distinct conceptions of beginning teacher competence were identified, with a further finding that individual beginning teachers were not limited to one conception, but conceived of competence in multiple ways. Because the relational nature of competence demands that it be investigated within the context in which it is experienced, this study also identified five different approaches to competence appraisal, as understood by the beginning teachers who had undergone the appraisal process. Comparisons of both conceptions of competence and approaches to appraisal were then compared to existing research in this area. This thesis presents an alternative view of competence and appraisal that may be used to further develop the process of appraisal and indeed, the professional development of beginning teachers.

Image super-resolution aims to produce a higher resolution representation of a scene from an ensemble of low-resolution images that may be warped, aliased, blurred and degraded by noise. There are a variety of methods for performing super-resolution described in the literature, and in general they consist of three major steps: image registration, fusion and deblurring. This thesis proposes a novel method of performing the first two of these steps. The ultimate aim of image super-resolution is to produce a higher-quality image that is visually clearer, sharper and contains more detail than the individual input images. Machine algorithms can not assess images qualitatively and typically use a quantitative error criterion, often least-squares. This thesis aims to optimise leastsquares directly using a fast method, in particular one that can be implemented using linear filters; hence, a closed-form solution is required. The concepts of optimal interpolation and resampling are derived and demonstrated in practice. Optimal filters optimised on one image are shown to perform nearoptimally on other images, suggesting that common image features, such as stepedges, can be used to optimise a near-optimal filter without requiring the knowledge of the ground-truth output. This leads to the construction of a pulse model, which is used to derive filters for resampling non-uniformly sampled images that result from the fusion of registered input images. An experimental comparison shows that a 10th order pulse model-based filter outperforms a number of methods common in the literature. The use of optimal interpolation for image registration linearises an otherwise nonlinear problem, resulting in a direct solution. Experimental analysis is used to show that optimal interpolation-based registration outperforms a number of existing methods, both iterative and direct, at a range of noise levels and for both heavily aliased images and images with a limited degree of aliasing. The proposed method offers flexibility in terms of the size of the region of support, offering a good trade-off in terms of computational complexity and accuracy of registration. Together, optimal interpolation-based registration and fusion are shown to perform fast, direct and effective super-resolution.

Image super-resolution aims to produce a higher resolution representation of a scene from an ensemble of low-resolution images that may be warped, aliased, blurred and degraded by noise. There are a variety of methods for performing super-resolution described in the literature, and in general they consist of three major steps: image registration, fusion and deblurring. This thesis proposes a novel method of performing the first two of these steps. The ultimate aim of image super-resolution is to produce a higher-quality image that is visually clearer, sharper and contains more detail than the individual input images. Machine algorithms can not assess images qualitatively and typically use a quantitative error criterion, often least-squares. This thesis aims to optimise leastsquares directly using a fast method, in particular one that can be implemented using linear filters; hence, a closed-form solution is required. The concepts of optimal interpolation and resampling are derived and demonstrated in practice. Optimal filters optimised on one image are shown to perform nearoptimally on other images, suggesting that common image features, such as stepedges, can be used to optimise a near-optimal filter without requiring the knowledge of the ground-truth output. This leads to the construction of a pulse model, which is used to derive filters for resampling non-uniformly sampled images that result from the fusion of registered input images. An experimental comparison shows that a 10th order pulse model-based filter outperforms a number of methods common in the literature. The use of optimal interpolation for image registration linearises an otherwise nonlinear problem, resulting in a direct solution. Experimental analysis is used to show that optimal interpolation-based registration outperforms a number of existing methods, both iterative and direct, at a range of noise levels and for both heavily aliased images and images with a limited degree of aliasing. The proposed method offers flexibility in terms of the size of the region of support, offering a good trade-off in terms of computational complexity and accuracy of registration. Together, optimal interpolation-based registration and fusion are shown to perform fast, direct and effective super-resolution.

La microscopie confocale classique permet d'obtenir des images à haute réso- lution de cellules en culture ou dans un tissu biologique excisé. Cette technologie peut être adaptée aux applications in vivo grâce à l'utilisation de fibres optiques et d'optiques miniaturisées. A terme, la microscopie confocale fibrée devrait permettre aux médecins et biologistes de réaliser des biopsies optiques; c'est à dire un exa- men histologique, en temps réel, des tissus biologiques à l'intérieur d'un organisme vivant et directement au contact de la zone d'intérêt. Le but premier de cette thèse est de dépasser les limites matérielles de ces in- struments d'imagerie en développant des outils de recalage d'images spécifiques et innovants. En particulier, le propos de ce manuscrit est cadré par l'objectif de pro- poser, au travers d'outils de création de mosaïques d'images, des biopsies optiques à grand champ aux médecins. Cette application est considérée, dans cette thèse, comme un système, ou un circuit, qui prendrait en entrée un flot de données brutes et délivrerait en sortie des mosaïques d'images à grand champ. Nous détaillons les éléments critiques de ce système, en particulier la reconstruction d'images en temps réel, le recalage linéaire d'images et le recalage non linéaire, avant de présenter la structure du système complet. Les données brutes produites par la microscopie confocale fibrée sont difficiles à interpréter parce qu'elle sont modulées par la structure en nid d'abeille du réseau de fibres optiques et parce qu'elle sont entachées d'artefacts géométriques. Dans ce contexte, nous montrons qu'une reconstruction en temps réel des images peut être utilisée en pré-traitement afin de produire des séquences vidéos directement interprétables. Comme la microscopie confocale fibrée est une imagerie qui se fait au contact des tissus, le mouvement relatif du tissu par rapport à la sonde optique implique qu'il est parfois difficile d'obtenir de manière robuste certaines mesures quantitatives d'intérêt. Nous avons donc attaqué le problème du recalage linéaire, efficace et robuste de paires d'images. Nous montrons que des outils ré- cents provenant du domaine du contrôle robotique par la vision peuvent surpasser les solutions standards utilisées en analyse d'images biomédicales. L'adéquation de ces outils au problème du recalage linéaire d'images nous a amenés à revisiter le problème du recalage non-linéaire. En interprétant le recalage non-linéaire comme un problème d'optimisation sur un groupe de Lie, nous développons un algorithme rapide de recalage difféomorphe non-paramétrique d'images. En plus d'être dif- féomorphe, notre algorithme produit des résultats qui sont similaires à ceux de l'algorithme des démons de Thirion mais qui sont plus lisses et plus proche de la vérité. Finalement, nous obtenons une boîte à outils de reconstruction et de recalage d'images que nous utilisons pour proposer un algorithme robuste de création de mosaïques d'images qui permette de calculer un alignement globalement cohérent à partir de résultats locaux, de compenser les distorsions liées au mouvement et de retrouver les déformations non-rigides. Par ailleurs, notre algorithme de mosaïques d'images a récemment été incorporé dans un essai clinique multicentrique. Cet essai illustre l'intérêt clinique de nos outils dans le cadre spécifique de la surveillance de l'oesophage de Barrett.

<p>This thesis describes and evaluates a number of algorithms for reducing fixed pattern noise in image sequences. Fixed pattern noise is the dominantnoise component for many infrared detector systems, perceived as a superimposed pattern that is approximately constant for all image frames. </p><p>Primarily, methods based on estimation of the movement between individual image frames are studied. Using scene-matching techniques, global motion between frames can be successfully registered with sub-pixel accuracy. This allows each scene pixel to be traced along a path of individual detector elements. Assuming a static scene, differences in pixel intensities are caused by fixed pattern noise that can be estimated and removed. </p><p>The algorithms have been tested by using real image data from existing infrared imaging systems with good results. The tests include both a two-dimensional focal plane array detector and a linear scanning one-dimensional detector, in different scene conditions.</p>

<p>Att mäkla på Franska Rivieran som svensk till svenska kunder skiljer sig från att mäkla i Sverige. Exempel på det är att man använder sig av ett juridiskt ombud, en notarie vid kontraktsskrivning i Frankrike. Där förekommer heller inte budgivning då detta är olagligt. Istället förekommer ofta prutning mellan köpare och säljare. Mäklaren arbetar även ofta närmare köparen än i Sverige, då man hjälper denne med kringtjänster som t.ex. att förmedla bankkontakter, hantverkare osv. Förmedling förekommer med fransk mäklarregistrering, med svensk mäklarregistrering och utan någon registrering eller utbildning alls. Detta har skapat irritation hos mäklarna på marknaden, då var och en försvarar sitt sätt att mäkla och betraktar sig som seriös.</p> / <p>To operate as an estate agent on the French Riviera as a Swede to Swedish customers, is quite different from dealing in real estate in Sweden. An example of this is that an articled clerk is required to establish the final contracts in France. Biddings on estates do not exist, as this is not allowed. Instead of this bargaining to bring down the price is often used between the buyer and seller. The estate agent is also working in closer contact with the buyer than In Sweden, as you help with other services as creating bank contacts, recommending craftsmen etc. Estate agents operate with French registration, with Swedish registration and without any registration or education at all. This has created irritation between the real estate agents on this market, as each one of them defends his way to operate, and consider himself serious.</p>

Att mäkla på Franska Rivieran som svensk till svenska kunder skiljer sig från att mäkla i Sverige. Exempel på det är att man använder sig av ett juridiskt ombud, en notarie vid kontraktsskrivning i Frankrike. Där förekommer heller inte budgivning då detta är olagligt. Istället förekommer ofta prutning mellan köpare och säljare. Mäklaren arbetar även ofta närmare köparen än i Sverige, då man hjälper denne med kringtjänster som t.ex. att förmedla bankkontakter, hantverkare osv. Förmedling förekommer med fransk mäklarregistrering, med svensk mäklarregistrering och utan någon registrering eller utbildning alls. Detta har skapat irritation hos mäklarna på marknaden, då var och en försvarar sitt sätt att mäkla och betraktar sig som seriös. / To operate as an estate agent on the French Riviera as a Swede to Swedish customers, is quite different from dealing in real estate in Sweden. An example of this is that an articled clerk is required to establish the final contracts in France. Biddings on estates do not exist, as this is not allowed. Instead of this bargaining to bring down the price is often used between the buyer and seller. The estate agent is also working in closer contact with the buyer than In Sweden, as you help with other services as creating bank contacts, recommending craftsmen etc. Estate agents operate with French registration, with Swedish registration and without any registration or education at all. This has created irritation between the real estate agents on this market, as each one of them defends his way to operate, and consider himself serious.

The objective of the proposed research is to develop methods that couple an expert user's guidance with automatic image segmentation and registration algorithms. Often, complex processes such as fire, anatomical changes/variations in human bodies, or unpredictable human behavior produce the target images; in these cases, creating a model that precisely describes the process is not feasible. A common solution is to make simplifying assumptions when performing detection, segmentation, or registration tasks automatically. However, when these assumptions are not satisfied, the results are unsatisfactory. Hence, removing these, often times stringent, assumptions at the cost of minimal user input is considered an acceptable trade-off. Three milestones towards reaching this goal have been achieved. First, an interactive image segmentation approach was created in which the user is coupled in a closed-loop control system with a level set segmentation algorithm. The user's expert knowledge is combined with the speed of automatic segmentation. Second, a stochastic point set registration algorithm is presented. The point sets can be derived from simple user input (e.g. a thresholding operation), and time consuming correspondence labeling is not required. Furthermore, common smoothness assumptions on the non-rigid deformation field are removed. Third, a stochastic image registration algorithm is designed to capture large misalignments. For future research, several improvements of the registration are proposed, and an iterative, landmark based segmentation approach, which couples the segmentation and registration, is envisioned.