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The Global ETD Search service is a free service for researchers
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Showing 41 to 47 of 47 (0.021 seconds)Spelling suggestions: "subject:"closedcircuit"" "subject:"based：circuit""
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Closed circuit television as a surveillance technique: a case study of filling stations in Middelburg, Mpumalanga, South AfricaNgwenya, Mboiko Obed 08 November 2012 (has links)
The researcher attempts to establish how CCTV footage can be used as a surveillance technique, for evidence gained in that way to be admissible in court. To conduct effective investigation, it is important for investigators to be familiar with the application of CCTV footage, its purpose, its benefits and shortfalls.
To achieve the goals and objectives of the practice of CCTV footage, investigators must know how to utilise the value of its evidence, and how to use it to identify suspects.
The clarification and application to the crime situation, the identification of the perpetrator or suspect of a criminal act is mostly impossible, if CCTV footage is not available to assist in identification and tracing of suspects. / Police Practice / M. Tech. (Forensic Investigation)
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Criticality and Risk Assessment for Pipe Rehabilitation in the City of Santa Barbara Sewer SystemRossi, Rossi Carmelo, II 01 June 2015 (has links) (PDF)
Aging sewer infrastructure is posing greater and greater risk to the health and well-being of City residents. Issues can range from pipe blockages in sewer laterals to Sanitary Sewer Overflows. This thesis develops a risk analysis method that can be used by municipalities to maintain and rehabilitate sewer assets. Risk combines the effect of Likelihood of Failure (LOF) and Consequence of Failure (COF) to perform a complete two-dimensional analysis that allows for relative comparison between different pipes in the system. The LOF rating has been equated to pipe integrity while the COF rating was related to the environmental, economic, and social consequences to pipe failure.
In order to estimate pipe integrity Closed Circuit Television (CCTV) scores from the City of Santa Barbara were used in combination with spatial and physical properties associated with each pipe. The CCTV scores were simply integer values between 0 and 5 based on the National Association of Sewer Services Company’s (NASSCO) Pipeline Assessment Certification Program (PACP) results. The quantitative parameters included pipe material and age, distance from restaurants, distance from any above ground water source, pipe depth below the ground surface, pipe length, and vehicular traffic volumes. The sensitivity analysis compared the given structural integrity scores with the predicted scores based on the weighted scoring method. It isolated four out of six of the parameters tested that affected the structural integrity of sewer pipes: material and age (45%), pipe depth (20%), Vehicular Traffic (10%), and distance from an above-ground water source (25%). A program was created in the C programming language that iteratively determined the percentage for each factor. These percentage factors are used to obtain the predicted structural integrity score for all the pipes.
Like the LOF rating, the COF rating consisted of scores between 0 and 5. The COF rating used pipe diameter, distance from commercial zones, distance from critical infrastructure, and vehicular traffic volume as parameters for quantifying the environmental, economic, and social consequences. These factors were determined from review of past literature and given approximately equal weighting when determining the COF rating values. The environmental factor, pipe diameter, was given a percentage factor of 30%; the economic factor, distance to commercial zones, was given a percentage factor of 30%; and the social concerns, distance to critical infrastructure and vehicular traffic volume, were given percentage factors of 20% each.
Finally, the risk for each pipe was determined in Geographic Information Systems (GIS) by combining the predicted structural integrity score or LOF rating and COF rating value for each pipe. This generated color-coded maps that showed distinct pipes that had the most critical predicted structural integrity scores, highest consequence, and the pipes with the most risk. This process could be used by any City to create a maintenance and rehabilitation schedule and plan for future CCTV inspections.
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La question de l'espace dans l'installation vidéo / The question of space in the video installationVatsella, Christina 10 December 2012 (has links)
Ayant comme point de départ les premières expérimentations de Nam June Paik avec les téléviseurs au début des années 1960, cette étude suit l’évolution historique de l’installation vidéo en parcourant cinq décennies de création. La problématique de l’espace, fil conducteur de cette recherche, nous amène d’abord à la constitution d’une typologie. Fruit de l’étude de l’évolution des formes principales de l’installation vidéo, cette classification a pour objet l’œuvre sous sa forme aboutie, c’est-à-dire installée. Néanmoins, cet état n’est que le résultat final d’un long processus. Divisée en quatre étapes, l’étude de la mise en espace de l’œuvre soulève des questions cruciales liées à l’acquisition, l’exposition et la conservation de l’installation vidéo. Une fois que l’œuvre est installée, elle s’articule autour d’un espace-temps virtuel, celui de l’image vidéographique, et d’un espace-temps réel, celui du dispositif plastique, analysés dans la troisième et dernière partie. Cette étude met l’accent sur la dimension historique de l’installation vidéo tout en la contextualisant au sein de l’histoire de l’art du vingtième siècle. / Having as a starting point Nam June Paik’s experimentations with televisions in the early 1960s, this essay traces the history of the video installation spanning five decades. The question of space is the basic thread of the analysis. It has led to the constitution of a typology that examines the evolution of the main forms of the video installation. This classification focuses on the artwork that is already installed. However, this state is the outcome of a complicated procedure. Divided into four steps and thoroughly examined, this process raises some crucial questions concerning the acquisition, the exposition and the conservation of the video installation. When installed, the artwork acquires two spatiotemporal dimensions, namely the virtual space and time of the video image and the real space and time of the installation, both analysed in the third chapter. This essay stresses the historical aspect of the video installation by situating it within the broader context of the 20th century history of art.
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A closed circuit electro-hydraulic actuator with energy recuperation capabilityQu, Shaoyang, Fassbender, David, Vacca, Andrea, Busquets, Enrique, Neumann, Uwe 23 June 2020 (has links)
The recent electrification trend in the off-road market has incentivized research towards the proposal of compact, cost-effective and energy-efficient solutions for hydraulic actuators. As a result, increased attention has been given to electro-hydraulic actuator (EHA) architectures. The paper offers a study performed on a novel closed-circuit EHA architecture with the goal to maximize the overall system efficiency while meeting or exceeding traditional off-road applications performance, thereby enabling further electrification of off-road applications. Both numerical and experimental approaches are utilized to validate the functionality of the proposed EHA circuital configuration in four quadrants. Moreover, the actuator functionality at both high and low velocities are considered, which has never been explored in the past due to the limitations on the hydraulic machine driving speed. The good match between the experimental data and the simulation results confirms the potential of the simulation model for sizing such EHA architecture for different actuator sizes, duty cycles, and performance levels.
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A Comparison of the Effectiveness of Videotape (Closed Circuit Television) versus Live Group Infant Care Classes, as a Teaching Tool for Post-Partum Mothers / CCTV vs. Classes as a Teaching Tool for Post-Partum MothersTorr, Elizabeth 04 1900 (has links)
This study is designed to assess the effectiveness of closed-circuit television (CCTV) as a post-partum teaching tool using an interactive problem-solving approach, compared with conventional group classes, in fostering the acquisition of skills and knowledge around baby care. A second primary objective is to determine the level of satisfaction of respondents with both approaches to post-partum education. An extensive discussion of the theoretical basis for the proposal is presented, drawing upon and synthesising concepts from the literature of Sociology, Education and Health Sciences. The conceptual model (Sword 1990) represents a synthesis of Mezirow’s (1978) theory of the transformation of meaning perspective with D’Zurilla’s (1986) cognitive-appraisal approach to the acquisition of new knowledge. In addition, adult learning principles are applied to the selected teaching strategies to identify optimal conditions of learning (Zemke and Zemke 1988). A two-group cohort design was used for randomisation, and the data collected was subjected to both quantitative and qualitative analysis. Two measures of learning were not significantly different for the videotape and live class groups. Statistically significant differences were identified between the groups in the attitude measures of convenience and ease of understanding. There was also a measurable difference in levels of satisfaction with the different approaches used. However, the results of this study suggest that combining an interactive, problem-solving approach to post-partum education with CCTV, is no more effective than live group classes in achieving knowledge acquisition for new mothers. CCTV can be used to address the basic and repetitive aspects of patient education and it appears to be effective for short-term knowledge gain. Several issues for further study are proposed in relation to the planning and implementation of alternative approaches to conventional post-partum teaching, as well as the design of future televised patient education programmes. / Thesis / Master of Science (MSc)
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Modelling, simulation and optimisation of a crushing plantNdhlala, Blessing 07 1900 (has links)
African copper PLC’s flagship is the copper producing Mowana mine located 129 km from Francistown in the North-Eastern part of the Republic of Botswana. The processing operation at Mowana is a standard flotation plant designed to produce copper concentrates from oxide, supergene, and sulphide ores. The expected average output of 16.2 tons per hour of copper concentrates has never been attained since plant commissioning. The major bottleneck has been established to be located around the crushing circuit of the Mowana production chain.
The major hypotheses of this research are that performance in a crushing plant is adversely influenced by moderate and discrete changes in the process. The ultimate objective is to develop a dynamic process simulator, administered in Simulink/MATLAB® background, for application in the design of a control model utilising two crusher variables and a self-tuning control algorithm.
In this research work, a process model describing the dynamic operation of an Osborn 57S gyrasphere cone crusher is investigated. Modelling of the Mowana crushing circuit is carried out by combining the steady-state and dynamic components of the crushing equipment in the Simulink/Matlab® environment. Eccentric speed (ES) and closed-side setting (CSS) are amongst the important inputs to the models. The rest of the inputs (crusher power, crusher cavity level, federate, pulley diameters, liner wear measurement, number of teeth of the pinion and bevel gear) are extracted from the data collected across the Mowana mine crushing circuit. While it has been demonstrated that the crusher CSS is the most influential controllable parameter, it has also been demonstrated that crusher capacity and power can be used effectively to optimise the circuit. The use of crushing power and cavity level control is suitable for the crushing circuit since the crushers are running on a constant ES and the CSS is set and reset manually.
The outcome of the study presents an insight into the optimization of the Mowana mine crushing circuit through the design of a self-tuning controller for the cone crusher and for prototyping, parameters of a PID controller were determined in the Simulink/MATLAB® environment. The simulation involved the optimisation of the control model as a function of the cavity level of and the power drawn by the cone crusher. A self-tuning control algorithm at PLC and SCADA level of control was then tested. This formed the simulations and training platform.
The outcome of the simulations carried out in this research needs to be validated against the real Mowana crushing process control upgrade. This will then inform the modifications and recommended crusher motor resizing exercise to be implemented. / Electrical and Mining Engineering / M. Tech. (Engineering: Electrical)
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Mathematical modelling of primary alkaline batteriesJohansen, Jonathan Frederick January 2007 (has links)
Three mathematical models, two of primary alkaline battery cathode discharge, and one of primary alkaline battery discharge, are developed, presented, solved and investigated in this thesis. The primary aim of this work is to improve our understanding of the complex, interrelated and nonlinear processes that occur within primary alkaline batteries during discharge. We use perturbation techniques and Laplace transforms to analyse and simplify an existing model of primary alkaline battery cathode under galvanostatic discharge. The process highlights key phenomena, and removes those phenomena that have very little effect on discharge from the model. We find that electrolyte variation within Electrolytic Manganese Dioxide (EMD) particles is negligible, but proton diffusion within EMD crystals is important. The simplification process results in a significant reduction in the number of model equations, and greatly decreases the computational overhead of the numerical simulation software. In addition, the model results based on this simplified framework compare well with available experimental data. The second model of the primary alkaline battery cathode discharge simulates step potential electrochemical spectroscopy discharges, and is used to improve our understanding of the multi-reaction nature of the reduction of EMD. We find that a single-reaction framework is able to simulate multi-reaction behaviour through the use of a nonlinear ion-ion interaction term. The third model simulates the full primary alkaline battery system, and accounts for the precipitation of zinc oxide within the separator (and other regions), and subsequent internal short circuit through this phase. It was found that an internal short circuit is created at the beginning of discharge, and this self-discharge may be exacerbated by discharging the cell intermittently. We find that using a thicker separator paper is a very effective way of minimising self-discharge behaviour. The equations describing the three models are solved numerically in MATLABR, using three pieces of numerical simulation software. They provide a flexible and powerful set of primary alkaline battery discharge prediction tools, that leverage the simplified model framework, allowing them to be easily run on a desktop PC.
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