This thesis evaluates the influence of family life cycle stages as a factor of residential tenure choice. The importance of tenure choice is being more widely recognized through the greater use of housing market and demand models. The purpose of this thesis is to contribute to the knowledge of the tenure decision process so that planners, policy makers, and other market participants are more effective in achieving their goals. In this study an empirical analysis is performed using urban Canadian data for households with head's between the age of 25 and 44. Eight family life cycle stages are used to classify households. A joint tenure choice and mobility model is used to test for ownership probability differences among the life cycle stages. Within the study framework allowances are made for recent and non-recent movers. The results indicate that family life cycle stages impact on tenure choice, and that this occurs outside of their impact on expected mobility (or holding period). The life cycle stage impact is strong through the effect of household reactions to income and wealth, and weak through just group membership. This suggests that utility preferences for ownership tend to shift as households progress through various life cycle stages. When elasticities are estimated they are found to reflect the different housing consumption and mobility decisions of households at different family life cycle stages. This also supports the concept of a changing utility preference function. In general this study finds that tenure choice is affected by consumption and mobility influences that result from different family life cycle stage demands. Further research studies, government and business policies, dealing with residential tenure choice are encouraged to recognize family life cycle stages and the impact of household expected mobility. / Business, Sauder School of / Real Estate Division / Graduate

Advances in materials technology, information and management systems have led to improvements in the engineering design, procurement, construction, installation and commissioning of process columns. The development of the front-end engineering design (FEED) process has led to the incorporation of best practices in the specification of equipment on projects during the design phase. The aim of the research is to investigate whether technical specifications have an impact on the life cycle costs of process columns. Adding to the initial capital cost of equipment, in the form of technical specification requirements, in an attempt to reduce life cycle costs, is always challenged during the project phase of a product life cycle. The principle of designing for the full product life cycle of process columns requires that consideration for both the project and operating life cycle be made at the stage of basic engineering. What is important to note is that the potential for life cycle cost savings at the beginning of a product life cycle is higher than during the operating life cycle. Figure S.1 illustrates this concept, and what is observed is that the potential for life cycle cost savings diminishes as the product life progresses over time. Process columns were chosen as the type of equipment to be investigated based on the nature, size and complexity of the equipment when compared to other equipment on a processing unit. Process columns are amongst the highest capital cost pieces of equipment in petrochemical units and usually have many auxiliary pieces of equipment associated with it in a system i.e. reboilers, condensers, pumps etc. / Dissertation (MEng)--University of Pretoria, 2009. / Graduate School of Technology Management (GSTM) / unrestricted

Orientador: Flavio Alessandro Serrão Gonçalves / Resumo: A estimação do tempo de vida útil de um transformador de potência pode viabilizar a melhoria do uso do ativo, bem como do planejamento quanto a sua confiabilidade frente ao seu impacto no sistema elétrico de potência por falhas. Neste contexto este trabalho realiza uma análise das principais metodologias de avaliação para ciclos de vida útil de transformadores de potência. As análises utilizam dados de medição de grandezas elétricas, medições de temperatura, além das quantificações dos elementos químicos e físicos presentes nos isolantes líquidos dos transformadores. O desenvolvimento concentra-se no estudo e reprodução de 2 metodologias, a primeira embasada na avaliação de um indexador de saúde dos transformadores e uma segunda metodologia que utiliza uma análise combinatória de indexador de saúde com posterior tratamento estatístico, para as reproduções das metodologias foram utilizados dados de operação, manutenções preventivas e corretivas referentes ao parque instalado de 290 transformadores em operação, com potências nominais entre 12,5 MVA e 50 MVA e com tensões em seu enrolamento de alta tensão de 69 kV e 138 kV, de uma distribuidora de energia. Posteriormente à reprodução dos modelos de forma massiva, foram avaliadas as suas respostas quanto aos dados e realizadas análises críticas do desempenho das máquinas frente as metodologias utilizadas. / The estimation of the useful life of a power transformer can enable the improvement of the asset’s use, as well as the planning of its reliability in relation to its impact on the power system due to fails. In this context this work performs an analysis of the main evaluation methodologies for power transformer life cycles. The analysis uses electrical measurement data, temperature measurements, as well as quantification of chemical and physical elements present in the liquid insulation of the transformers. The development focuses on the study and reproduction of two methodologies, the first one based on the evaluation of a health index of the transformers a second methodology that uses a combinatorial analysis of health index subsequent reprocessing of the methodologies, operation data, preventive and corrective maintenance were used for 290 installed transformers, with rated power between 12.5 MVA and 50 MVA and with voltages in its high voltage winding of 69 kV and 138 kV from an energy distributor. After the application of the models in a massive way, their answers results were evaluated and critical analysis of the performance of the machines were carried out against the methodologies used. / Mestre

京都大学 / 0048 / 新制・論文博士 / 博士(農学) / 乙第13339号 / 論農博第2882号 / 新制||農||1079(附属図書館) / 学位論文||R2||N5246(農学部図書室) / 京都大学大学院農学研究科応用生物科学専攻 / (主査)教授 山下 洋, 教授 朝倉 彰, 准教授 益田 玲爾 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Successful service coordination for the homeless depends on the ability of diverse organizations to effectively collaborate. This study utilizes a life-cycle framework to expand on the collaborative governance theory by highlighting the different stages of collaboration that homeless service networks encounter. Activation, collectivity, and institutionalization are three stages used to uncover the unique nature of emergency discharge planning processes. Since collaboration is not a static process and government regulation for emergency discharge plans were recently enacted in 2012, collaborative networks encounter challenges and success factors at different stages. A qualitative case-study approach of organizational leaders in homeless service networks in Texas (Dallas, Ft. Worth and Houston) examines stages of collaboration. Results show common success and challenge factors identified among the three networks, but the factors take on different forms in relation to where the networks are at in the coordination stages. Practitioners can use the findings from this study as a guide to set up benchmarks and measurable objectives to identify strengths and weaknesses in their coordination processes.

Multiple drive belt conveyors are being increasingly incorporated in mining plans worldwide because of their high economic performance and the ease of moving these installations around, especially in underground mines. A typical modern multi-drive conveyor system consists of one or more intermediate drive stations positioned along the upper stretch of the conveyor and a single drive station situated in the lower stretch. Despite the acknowledged cost saving potential of the multiple drive technology, no previous work was reported on the methodology to realize a cost-effective design of multi-drive belt conveyors. This study investigates a design approach for multiple drive belt conveyors with the objective to achieve the lowest life cycle cost of multi-drive belt conveyors for a specified material transport task. For this purpose, an optimization model for the cost-effective design of multi-drive conveyor systems is formulated on the basis of the recommendations of the DIN 22101 and SANS 1313 standards. For a given number of intermediate drive stations, the proposed model optimizes a set of design parameters so that the minimum equivalent annual cost of a conveyor can be attained whilst handling the transport requirements and design conditions. The conveyor parameters optimized in this study are the rated powers of motors, the rated torques of gear reducers, the diameters and wrap angles of drive pulleys, the belt width, the belt speed, the lengths of the belt sections not nestled between drive pulleys, the spacings between idler rolls and the shell diameters and shaft diameters of idler rolls. For benchmark analysis purposes, a similar optimization model is also developed for the single drive technology. Described as mixed integer nonlinear programming (MINLP) problems, the two optimization models are solved using the MIDACO solver embedded in the MATLAB environment. The results of this study show the validity and effectiveness of the design model proposed for multi-drive belt conveyors. The results also indicate that the multiple drive technology is more beneficial for the conveying over long distances. The impact of the possible instability of inflation throughout the project lifetime is also investigated through three hypothetical scenarios, which involve a fixed inflation rate, a higher fluctuating inflation rate and a lower fluctuating inflation rate, respectively. The results of this sensitivity analysis show that the most cost-effective multi-drive belt conveyors obtained under a fixed inflation rate is robust enough against limited fluctuations of this parameter. / Dissertation (MEng)--University of Pretoria, 2017. / Electrical, Electronic and Computer Engineering / MEng / Unrestricted

The Federal Aviation Administration (FAA) is developing a new software information system -- the Surface Movement Advisor (SMA). This system development program has progressed through part of the system engineering process and is currently at a stage where additional funding will be required to complete the development. The budget for R&D at the FAA is tight and several new programs are vying for limited funds. To secure funding for further development the SMA system team must again demonstrate that it has a cost effective solution that is beneficial to the airlines and their passengers. The purpose of this project was to gather, structure, and analyze cost data and benefit information within the context of the systems engineering process as being practiced by the FAA and their SMA contractors. <p>The requirements for the SMA system are based on the fact that the developers have confirmed operational deficiencies concerning accurate and timely information about the status, position, and movement of commercial aircraft on the ground at the major airports in the country. This deficiency causes excessive and costly ground delays of aircraft. With proper information the ground controllers in the control towers will be able to direct ground traffic more efficiently and reduce the costly delays. The designers have confirmed the need for the system. They have developed feasible concepts, listed the requirements for the system, system specifications, and some preliminary designs. The systems engineers now must now decide among three design alternatives. <p>This project demonstrates a systems engineering approach to the evaluation of these design alternatives, selection of the preferred alternative and demonstration of possible benefits to justify further funding. This is the first cost and benefit analysis and many of the costs and benefits are best estimates. At later stages in the development cycle costs and benefits will be analyzed again using more current data, more accurate assumptions, and results from prototype testing and evaluation. The estimates will become more accurate in the detailed design phase in the future. / Master of Science

Master of Science

In today's society, the disposal of hazardous and non-hazardous waste is an ever growing problem. Legislation has become increasingly stringent with regard to protecting the environment from groundwater contamination. As documented by the EPA, the proportion of waste disposed of in landfills has steadily declined throughout the past thirty years due to source reduction, waste diversion to combustion facilities, and material recovery efforts. <p>This project examines the effects of material recovery levels on landfill life-cycle costs. A model has been developed to study the relationships between the operational costs, profit, and material recovery levels. The landfill in King George County, Virginia is used as the basis for studying the effects of increasing the current state required material recovery level from 25% to 50%. / Master of Science

Dectes texanus LeConte (Coleoptera: Cerambycidae) is a longhorn beetle species endemic to eastern United States. Originally described as a pest of weeds from the family Asteraceae, D. texanus has expanded its host range and is found infesting the stems of soybeans, Glycine max (L.) through the southwestern and middle United States. Female D. texanus chews a hole in the epidermis of a petiole and oviposits on it. Then, the D. texanus larva depletes all the pith of the stem making a tunnel down to the base of the plant and girdle the stem about 5 cm above the soil line. When a force is applied to the girdling point, generally weather related (i.e. strong winds), the plant lodges. While D. texanus phenology has been described for some states, this topic has yet to be explored in Kentucky. The objectives of this study were: 1) to describe the life cycle and behavior of D. texanus in soybeans in Western Kentucky, 2) to study the effect of the stem diameter on the incidence of D. texanus infestations, 3) to evaluate the susceptibility of full-season and double-crop soybeans to D.texanus infestations, 4) investigate the efficacy of seed treatment in reducing D. texanus infestations, 5) to determine effects of D. texanus larval feeding in the physiological yield of soybeans. The results of these studies showed that: 1) there was no distinct peak of D. texanus emergence detected in the 2018 and 2019 growing seasons and pupation period varied with year and location; the best sampling period for D. texanus population should occur between 1000 and 1600 hours during the peak season with either a 5-gallon white plastic bucket or sweep net; 2) the probability of finding D. texanus infesting soybeans was higher when the stem diameter is larger than 9 mm, and smaller than 11 mm; 3) double-crop soybeans had reduced infestations of D. texanus because these soybean plants are not a suitable host when D. texanus was active ovipositing and the pith was not fully developed; 4) seeds treated with imidacloprid did not influence D. texanus infestation on soybeans, larvae presence in main and lateral stems, and parasitism occurrences; and 5) D. texanus did not affect seeds and pods attributes (pod width, length, height and weight), and yield. The latter may occur because feeding of D. texanus larva does not interfere on photosynthesis or nutrient transportation during seed fill.