A Rogowskl coil has been used to measure current in a pulsed discharge circuit. The frequency response of the coil has been determined experimentally, It has been established that the noise signal associated with the measurement of a pulsed discharge current is due principally to the electromagnetic radiation from the spark gap switches required in such a circuit. The radiation can be reduced by pressurizing the spark gap with argon, but at the same time the breakdown potential of the switch becomes erratic. A simple measuring system has been devised which completely eliminates the noise signal from the current waveform. The system consists of a balanced differential preamplifier which is fed by a completely balanced measuring circuit into which a 0.5µ sec delay line has been incorporated. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Currently, standard enhancement of three-channel colour digital imagery is not performed in a general fashion; it is dependent on the particular colour device used to display the imagery. By introducing a colour transformation, the enhancement can be standardized and therefore be defined in terms of other devices. In addition, the colour transformation can be defined such that the perceptual attributes of colour associated with an image are more easily manipulated. The purpose of this work is to examine a variety of such colour transformations and implement a subset of these on a colour CRT. / Science, Faculty of / Computer Science, Department of / Graduate

M. Ing. (Mechanical Engineering) / This research aims at identifying techniques which can be used to remove rain from a digitized rain distorted image. The research commenced with computer implemented rain removal techniques but also lead to camera obscuration techniques. Camera rain obscuration technique: Before a rainy scene is digitized, rain can be removed from the projected image by the correct selection of camera aperture and shutter speed settings. These settings will determine the way the real image is transformed through the lens and onto the recording plane. Computer image restoration technique: Rain removal after digitization is performed in both the frequency and the spatial domain by means of two dimensional image processing and filtering techniques. Time consuming frequency domain techniques were replaced by equivalent convolutional techniques. Experiments on simulated and real scenes corrupted with rain indicated that it is possible to improve the image appearance with only a marginal decrease in signal to noise ratio.

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This dissertation is a response to the call for theoretically coherent practical methods which encourage and facilitate systemic thinking in psychology (Boden, 1972; Jordaan & Jordaan, 1984; Lazarus, 1990; Norcross & Grencavage, 1990; Von Bertalanffy, 1968; Winburn, 1991). Teleonics is a developing ecology of process-based systems ideas, where process is foregrounded relative to structure. From a teleonics perspective, structure and process are viewed as inextricably linked, while the foregrounding of process is viewed as having significant implications for how meaning is constructed from observations. Given the dominance of the structure-based orientation to psychology during the modern period, a process-based systems approach is a contribution to the development of postmodern thinking in psychology. Through a process of reviewing the systems thinking literature, and illuminating those premises that point to a distinction between process- and structure-based thinking, the following process-based systems premises are punctuated: * life is essentially of a process nature, * nature is approximate rather than definite, * organization in nature is dynamic, * systems function according to principles of autonomy and integration, * creation is a process of emergence and * teleos is a character of living systems. By relating these premises to the field of psychology, further premises of governance and the union of opposites are punctuated. A review of selected psychological literature is provided to draw distinctions about how the abovementioned process-based systems premises relate to psychological theory and practice. In line with the postmodern trend to coherence between theory and practice, teleonics is proposed as a contribution not only to creative theory building but, also to application. In support of coherence between theory and practice in psychology, epistemological tools and tasks for systemic intervention are discussed. The methodological approach of this dissertation is consistent with the conceptual theorist style (Reason & Rowan, 1981 a). A systems methodology, namely that of double description (Bateson, 1979; Keeney, 1983) is used to connect the theoretical and the applied aspects of this study. The theoretical aspect of the double description was formulated by a review, synthesis and integration of the literature. The applied aspect was formulated by means of a report on fieldwork undertaken in the form of a series of case studies. A particular contribution of this dissertation is the specification and illustration of three teleonics maps namely, spiral mapping, teleos mapping and telentropy tracing. The application of these maps is presented via an elaborated format case study of an individual adult therapy case, and four further cases presented in a circumscribed format (Carlson-SabeIli & Sabelli, 1984). The circumscribed case studies include a single session intervention and a health enhancement workshop. The methodology of this dissertation can be located in new paradigm (postmodern) research. The soundness of endeavour (Reason, 1988c) of this dissertation can be appreciated in relation to validity in terms of the philosophical ideas supporting new paradigm research. Other contributions are that it promotes convergence and informed divergence in psychological theory, is an example of the development of systems theory at the level of micropractice, explores the concept of levels in psychology, and contributes to the further development of teleonics as a process-based systems ecology of ideas. The introduction of visual maps, as practical non-verbal tools for the communication of concepts and observations in psychological practice, is a particularly useful contribution. In this dissertation, teleonics is demonstrated as a process-based systems model which facilitates the practical operationalizing of process-based systems thinking.

A Dissertation submitted to the Faculty of Medicine, University of the Witwatersrand, Johannesburg, for the Degree of Master of Science (MED). JOHANNESBURG, 1986 / The Literature Review covers the immunosuppressive and immunopotentiating properties of antibiotics on the immune system and the effects these could have on the resolution of an infection. The possible pathogenic mechanisms of C. albicans are also reviewed in this section. The experimental section shows that pre-treatment of mice with erythromycin increases the mean survival time following intraperitoneal inoculation of C. albicans. It was shown that erythromycin enhanced lymphocyte transformation and PMNL migration in both in-vivo and in-vitro situations. These enhanced immunological components probably caused improved survival times in the aforementioned animal experiments. To investigate the effects of oral administration of erythromycin on in-vivo PMNL migration in adult volunteers a new quantitative test which could only be applied to humans was developed and is described in detail. Using this method preliminary data were obtained which show that erythromycin increases PMNL migration in-vivo. / IT2018

A dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Arts (Clinical Psychology) in the Department of Psychology, University of Zululand, South Africa, 2013. / The study investigated the effect of breathing techniques on test anxiety among students at the University of Zululand. Data was collected on a sample of one hundred (N=100) full time students aged between eighteen (18) and thirty two (32). The study consisted of the intervention group (N=60) and the control group (40). Results of the study indicated that participants in the intervention group obtained different results after the intervention of breathing techniques. There was a small discrepancy between the control and the intervention group in the post-test phase. This verified the hypothesis that breathing techniques had a positive effect on students with test anxiety. The results were however not statistically significant probably because of a shorter period of breathing intervention. On the whole, the intervention suggests that breathing does have a positive effect on test taking anxiety.

Les conducteurs des véhicules à deux-roues motorisés (V2RM) sont parmi les usagers les plus vulnérables sur les routes. En France, les V2RMs ne constituent que 1.9% du trafic routier, mais ils sont impliqués dans 24% des accidents mortels. Le manque des systèmes d’aide à la conduite (Intelligent Transportation System, ITS) est pointé du doigt parmi les principales causes de ces chiffres alarmants. En effet, la complexité de la dynamique des V2RMs ainsi que l’inaccessibilité à certains états (comme l’angle du roulis, le couple de direction et les forces pneumatiques) rendent le déploiement des systèmes ITS très difficile et constituent un frein quant à leur développement. Dans ce contexte, mon travail de thèse vise l’estimation des dynamiques pertinentes des V2RMs. Premièrement, un observateur de type Takagi-Sugeno (TS) est proposé pour l’estimation de la dynamique latérale avec un découplage du couple de direction qui est considéré comme une entrée inconnue (UI). Ensuite, afin d’estimer le couple de direction, un autre observateur TS est proposé. L’observateur en question possède une loi d’adaptation proportionnelle-dérivée (PD) afin de reconstruire l’UI. Cependant, dans les deux observateurs précédents, les non-linéarités associées aux forces pneumatiques latérales sont négligées. Pour contourner cette difficulté, les forces latérales sont considérées comme des entrées inconnues et sont estimées de manière algébrique en utilisant les observateurs par mode-glissant d’ordre supérieur. Enfin, nous nous sommes attelés à la dynamique longitudinale et proposé un observateur à entrées inconnues avec une loi d’adaptation PD afin d’estimer les forces longitudinales et les couples d’accélération et de freinage. Une fois les dynamiques latérales et longitudinales des V2RMs estimées, nous nous sommes attaqués à la commande du système de freinage. Dans ce contexte, un contrôleur robuste est proposé afin d’optimiser le freinage des V2RMs. Le contrôleur est basé sur les techniques par mode-glissant et permet d’asservir le glissement longitudinal vers un glissement de référence. Ce dernier est calculé grâce à un programme inspiré des algorithmes MPPT. Enfin, afin de valider les différents observateurs proposés, une commande basée observateur utilisant les techniques TS a été proposée dans afin d’automatiser un scooter instrumenté et assurer le suivi d’un roulis de référence. / Riders of Powered two-wheeled vehicles (P2WV) are among the most vulnerable drivers on roads. In France, riders of P2WVs are just 1.9% of road traffic, but account for 24% of road user deaths. This high rate of mortality may be explained by several factors. One of them is the lack of specific Intelligent Transportation System (ITS). In fact, because of the complexity of the P2WVs dynamics and the unavailability of some states (such as the steering torque, the roll angle and the lateral forces), it is more difficult to design specific ITS systems for P2WVs. In this context, my thesis aims the estimation of relevant dynamics of P2WVs. Firstly, a Takagi-Sugeno (TS) observer is proposed to estimate the lateral dynamics. The observer completely decouples the steering torque - which is considered as an unknown input (UI) - from the estimation error dynamics. Then, to estimate the lateral dynamics and the steering torque, another TS observer is proposed. The observer in question has a proportional derivative (PD) adaptation law to reconstruct the UI. However, in both observers, nonlinearities with respect to tire forces are neglected. To circumvent this difficulty, lateral forces are considered as UIs and they are algebraically estimated thanks to high order sliding mode observers. Finally, we focus on the longitudinal dynamics and propose an UI observer with a PD adaptation law to estimate the longitudinal forces and the thrust and braking torques. Once the lateral and longitudinal dynamics estimated, we were interested by the control of the braking system. In this context, a robust controller is proposed in order to optimize the braking for P2WVs. The controller is based on sliding mode techniques and allows the tracking of the longitudinal slip to a reference one. The latter is computed through a program inspired by MPPT algorithms. Finally, to validate the several observers developed in my thesis, an observer based controller using TS techniques is proposed in order to stabilize and automate an instrumented scooter and to track a reference roll angle.

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