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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
251

An analysis of the bilateral commodity flows between Taiwan & Japan in the light of the product cycle model.

January 1978 (has links)
Li Kam-chuen. / Thesis (M.Phil.)--Chinese University of Hong Kong. / Bibliography: leaves 174-180.
252

Cost-benefit analysis of microgenerators : an integrated appraisal perspective

Harajli, Hassan A. January 2009 (has links)
The UK domestic building sector accounts for a substantial amount of the final energy demand and greenhouse gas (GHG) emissions. To this extent, the sector can play an important role in GHG abatement and energy demand reduction, essential objectives of a more ‘sustainable energy system’. Microgeneration, or production of electricity or heat from small-scale sources, have been advocated by some, including the Supergen ‘Highly Distributed Power Systems Consortium’ to which this thesis contributes, as important means towards achieving these objectives. In this thesis, three assessed microgenerators; specifically a 600W microwind system, 2.1 kWp photovoltaic (PV) and building-integrated photovoltaic (BIPV) systems, and a 2.8m2 solar hot water (SHW) system have been analysed through an ‘integrated appraisal toolkit’ in order to assess their respective economic and financial performance in current UK context. A cost-benefit analysis (CBA) is applied, based on outputs and results from energy analysis and life-cycle assessment (LCA), and other tools such as financial appraisal, cost-effective analysis (CEA), and simple multi-attribute ranking technique (SMART) are also performed in order to asses how these systems perform on an individual household level or when compared to other energy technologies. The CBA, which included environmental impacts quantified through the LCA, obtained negative net present values (NPVs) for all the assessed microgenerators with the exception of microwind in a high-wind resourced ‘open’ area with lower end capital costs. The NPVs in the financial appraisal, which excluded environmental impacts, yielded relatively poorer results still. Only with the proposed feed-in tariffs would the systems all achieve positive NPVs. Given that the CBA included a substantial qualitative part, alternative tools, such as CEA and multi-criteria evaluation were applied (in brief) in order to place the assessed systems in the context of other energy generating sources in the UK, and to enable a more confident decision with respect to whether these systems should be advocated or rejected.
253

O desenvolvimento da contabilidade gerencial nas empresas: uma perspectiva de ciclo de vida / Management accounting development in organizations: a life cycle perspective

Necyk, George Anthony 19 March 2008 (has links)
Este trabalho teve como objetivo ampliar o entendimento de como a Contabilidade Gerencial se desenvolve ao longo do tempo em uma organização, tomando como base um modelo de estágios de ciclo de vida. Pressupõe-se que, em cada estágio de ciclo de vida, a organização assume características particulares e tem necessidades de informações específicas, o que impacta em suas práticas contábeis gerenciais. O modelo de ciclo de vida de Miller e Friesen (1984), para organizações em geral, e o trabalho de Moores e Yuen (2001), que o aplicou ao estudo da Contabilidade Gerencial, ambos baseados na Teoria da Configuração, formam o principal referencial teórico deste trabalho. A estratégia de pesquisa utilizada foi a de um estudo de caso único, que se justifica pela complexidade do tema e pela abordagem longitudinal retrospectiva. A empresa objeto deste estudo foi uma indústria de transformação com mais de 40 anos de idade. O horizonte de análise compreendeu o intervalo da história da empresa que iniciava de 1994 e findava em 2006, o momento presente, conforme os relatos dos profissionais da empresa selecionados como participantes da pesquisa. De um modo geral, as características observadas nos períodos identificados foram compatíveis com a descrição dos estágios correspondentes no referencial teórico. Foi possível constatar como a evolução dos estágios de ciclo de vida afeta o desenvolvimento da Contabilidade Gerencial dentro do mesmo estágio e na transição entre estágios distintos. Observou-se que o processo de transição não é necessariamente linear, em que o novo estágio se estabelece e daí os atributos de Contabilidade Gerencial são alterados. As evidências coletadas permitiram suportar as proposições nos estudos de Miller e Friesen (1984), mas apenas parcialmente aquelas derivadas do trabalho de Moores e Yuen (2001), já que nem todos os estágios de ciclo de vida puderam ser observados, neste caso. O trabalho conclui com sugestões para estudos futuros, na expectativa de que se continue ampliando o entendimento do tema do desenvolvimento da Contabilidade Gerencial. / The objective of this work was to expand the understanding of how Management Accounting develops through time in an organization, taking a life cycle stage model as reference. It is assumed that, in each life-cycle stage, the organization takes in particular characteristics and has specific information needs, which impacts its management accounting practices. Miller and Friesen (1984) life cycle model, for organizations in general, and Moores and Yuen (2001) work, that applied it to the study of Management Accounting, both based on Configuration Theory, are the main theoretical references of this work. A single case study research strategy was utilized, justified by the complexity of the theme and by a retrospective longitudinal approach. The subject of this study was a manufacturing company of over 40 years of age. The analyzed time horizon comprised a span of company history that started in 1994 and ended in 2006, the current period, in accordance to the interviews with the company professionals that were selected as participants of this research. In general terms, the observed characteristics in the identified periods were compatible with the corresponding life cycle stages descriptions as found in the referenced theory. It was possible to verify how life cycle stage evolution affects Management Accounting development within the same stage and in the transition between distinct stages. It was observed that the transition process is not necessarily linear, where a new stage establishes itself and then Management Accounting attributes are changed. The gathered evidences allowed the support of the propositions based on the Miller and Friesen (1984) studies, but only partially of those derived from the Moores and Yuen (2001) work, since not every life cycle stage was observed in this case. This work concludes with suggestions for future studies, hoping that the understanding of the Management Accounting development subject continues to grow.
254

Life cycle analysis of biomass derived hydrogen and methane as fuel vectors, and a critical analysis of their future development in the UK

Patterson, Tim January 2013 (has links)
Concerns over environmental impacts and long term availability of liquid fossil fuels means that sourcing alternative, renewable transport fuels has increased in importance. To date, implemented approaches have concentrated on the production of liquid biofuels biodiesel and bioethanol from crops. Even though technology for implementation is readily available in the form of biogas production and upgrading, gaseous fuels have been largely overlooked in the UK. Research completed showed that if produced from indigenous crops using currently viable technology, it is energetically more favourable to produce gaseous fuels rather than biodiesel or bioethanol with gaseous fuels also delivering some emission benefits at end use. To date, the subsidy system supporting biofuel production has not functioned well. Research showed that if the subsidies approached the maximum allowable value, and when produced from waste materials, the production of gaseous fuels can be economic compared to liquid biofuels. Life cycle assessment has showed that utilising biomethane as a vehicle fuel could be an environmentally appropriate approach if the conventional use for biogas of combusting in a combined heat and power plant cannot utilise the majority of the excess heat produced. A two stage process to produce a hydrogen / methane blend was shown to be energetically favourable when utilising wheat feed, although hydrogen production was low. The process was not energetically favourable when food waste was utilised, indicating the importance of optimising process according to feedstock characteristics. Life cycle assessment of electrolytic hydrogen production using a range of energy sources found that electrolysis driven by renewable energy was a valid option for future deployment. However, given current feedstock availability, indigenous biofuel production, regardless of the fuel produced, could only make minor contributions to overall fuel requirements. As such, a range of fuel vectors, or a significantly greater commitment of land resources to fuel production, will be required in the future.
255

Predicting the life cycle of technologies from patent data

Gebremariam, Merhawi Tewolde January 2019 (has links)
Analysis of patent documents is one way to learn about trends in the evolutionof technologies. In this thesis, we propose a mixture of life cycle Poisson modelfor predicting the life cycle of technologies from patent count data. The aim is topredict the life cycle of technologies and determine the stage of the technology inthe development S-curve. The model is constructed from historical data on patentpublications of technologies and also from experts’ belief of life cycle of technologies. The methods used to estimate the model are based on Bayesian methods, inparticular we use a combination of Gibbs sampling and slice sampling to simulatefrom the posterior distribution of the model parameters. We apply the model on adataset of 123 technologies from the electricity sector. As a preliminary exploratorystep clustering analysis is also applied on the dataset. Finally we evaluate the modelhow it performs to predict the trend of life cycle of technologies based on differentbase years. Results reveal that the model is capable of predicting the life cycleof technologies based on its different stages. However, the predictions of expectedbehavior become more accurate when more data is used to construct the prediction.
256

Biological and environmental efficiency of high producing dairy systems through application of life cycle analysis

Ross, Stephen Alexander January 2014 (has links)
Dairy production systems are an important global contributor to anthropogenic greenhouse gas (GHG) emissions including methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2). Due to the role GHG play in climate change, it is important to investigate ways to minimise their global warming potential (GWP) and to maximise the efficiency of dairy production systems. Finding a balance between improving productivity and suppressing the range and quantity of GHG produced in dairy production is crucial in order to maintain sustainability in the future. The Langhill herd is part of a long term genetic x feeding systems study, representative of a range of dairy production systems which may be found in the UK. Two feeding regimes (low forage (LF) and high forage (HF)) were applied to each of two genetic lines (control (C) and select (S) genetic merit for milk fat plus protein) giving four contrasting dairy production systems (LFC, LFS, HFC, HFS). Biological efficiency (production and energetic) and environmental efficiency (GWP) were assessed by way of life cycle analysis (LCA), accounting for dairy system inputs and outputs from off-farm production of imported feeds and fertilisers to raw milk leaving the farm gate over a period of seven years. Calculations were conducted using the Intergovernmental Panel on Climate Change (IPCC) methods, with system specific data implemented where possible. Select genetic line under low forage regime (LFS) had the highest gross production and energetic efficiencies (p<0.001). In LFS, milk yields were 56% higher per cow than the lowest ranked HFC system, representing a difference of around 3500kg per cow. Milk solids yield per kg dry matter intake was 18% higher in LFS compared to HFC. High forage with control genetic line required 17% more net energy intake than LFS to produce each kg of milk solids. LFS allocated the highest proportion of net energy to lactating after accounting for body maintenance (p<0.001). Rate of change in efficiency throughout lactation varied significantly (p<0.001) amongst systems, with loss of efficiency minimised in LFS and greatest in HFC. However, LFS involuntary culling rate was significantly higher than other systems (p<0.001). LFS was the most environmentally efficient system and HFC the least (p<0.001), both per unit productivity and per unit total land use. Implementing low forage regime with select genetic line lowered GWP per kg energy corrected milk (ECM) by 24% compared to HFC (p<0.001). GWP of LFC was around 8% lower per kg ECM than HFS (p<0.001). Methane from enteric fermentation contributed the greatest proportion of overall GWP (46-49%) in all systems. However, key factors in the differences amongst systems were higher off-farm CO2 equivalent emissions under low forage, and higher on-farm N2O emissions under high forage regime. HFC produced 91% more nitrous oxide per kg ECM from animal manures compared to LFS, and 65% more N2O from applied manufactured fertilisers (p<0.001). Conversely GWP associated with off-farm production of imported feeds in LFS was 11% higher than in HFC (p<0.001). In low forage systems high gross emissions were offset by high productivity but this was not the case for the high forage systems. Cows of high genetic merit managed under a Low Forage feeding regime had improved production, energetic and environmental efficiencies. However, issues with animal health and fertility raise questions about long term sustainability of the LFS dairy production system, emphasising the importance of examining trade offs between systems.
257

The normal distribution in life testing

Crosier, Ronald Blaine January 2010 (has links)
Typescript, etc. / Digitized by Kansas Correctional Industries
258

Avaliação da efetividade de arranjos tecnológicos e processuais na melhoria do desempenho ambiental da produção de fosfato bicálcico. / Evaluation of the effectiveness of technological and procedural arrangements in improving the environmental performance of production of dicalcium phosphate.

Martinho, Henrique Miguel 30 June 2014 (has links)
Ativo essencial na composição de produtos de nutrição, o fosfato bicálcico é aplicado como fonte de fósforo e cálcio em rações animais, sais minerais, e outros bens regularmente consumidos no segmento pecuário. Mesmo com uma contribuição importante para o sector agrícola nacional, a obtenção de fosfato bicálcico proporciona impactos significativos ao meio ambiente. Isso ocorre não apenas pelo consumo inexorável de rocha fosfática recursos naturais considerados como reserva estratégica de uma nação , mas também, por causa das demandas de água , de aditivos e de outros agentes de processo. Além disso, destacam-se nesse mesmo recorte a geração de resíduos sólidos e emissões para a água e para o ar, geradas em virtude da abordagem tecnológica praticado neste processamento. Este estudo faz uma avaliação do desempenho ambiental da produção de fosfato bicálcico como esta é praticada no Complexo Mineroquímico de Cajati -SP, sob a perspectiva de propor ações de melhoria ao mesmo processamento. A fim de levar a cabo a conte o presente desenvolvimento a técnica de Avaliação do Ciclo de Vida (LCA) a técnica foi utilizada para determina em termos quantitativos, a magnitude das interações entre os sistemas antrópicos e o ambiente. Os resultados da primeira etapa do projeto mostraram que a importação de enxofre, a produção de ácido fosfórico e o consumo de energia elétrica foram os estágios com o maior potencial de impactos ambientais. O diagnóstico fornecido por esta iniciativa permitiu que arranjos tecnológicos concebidas sob o enfoque ambiental fossem então modelados. Nesses termos, foram propostas melhorias quanto a logística do transporte de enxofre, o consumo de água no complexo industrial, e a aquisição de energia elétrica junto à concessionária. O estudo conclui que, se a importação de enxofre fosse realizada a partir de diferentes fornecedores, mas desconsiderando a Rússia o mais importante destes na condição atual o desempenho ambiental do processo seria afetado positivamente. Quanto ao consumo de água, a implementação de ações de reciclagem trouxe ganhos em termos de esgotamento do recurso, de eutrofização e de toxicidades em água doce e terrestre. Ainda que estes resultados fossem previsíveis, as magnitudes das reduções foram expressivas. No entanto, o uso de cal virgem para neutralização do efluente na nova estação de tratamento (ETEL) aumentou significativamente os impactos como mudanças climáticas. Por fim, a alternativa de fornecimento de energia eletricidade por cogeração de biomassa será ambientalmente eficaz se acaso esta puder proporcionar de maneira simultânea uma redução da demanda de energia térmica decorrente de combustíveis fósseis. / Essential asset in the composition of nutrition products, the dicalcium phosphate is applied as a source of phosphorus and calcium in animal rations, minerals salts and other regularity consumed goods in the livestock sector. Even with an important contribution to the national agricultural sector, the obtaining of dicalcium phosphate provides significant impacts to the environment. This occurs not only by the inexorable consumption of phosphate rock natural resources considered as strategic reserve of a nation but also, because of the demand for water, additives and other agents used in the process. Moreover, still regarding environmental effects, must be highlighted the solid waste generation and the emissions for water and to the air released by virtue of the technological approach usually practiced in this processing. This study makes an evaluation of the environmental performance of dicalcium phosphate production as it is practiced in the Complexo Mineroquímico of Cajati-SP, under the perspective to propose improvement actions. In order to carry out the development Life Cycle Analysis (LCA) technique was employed in order to determine, in a quantitative way, the magnitude of the interactions between the anthropic systems and its surroundings. The results of the first step of the project showed that sulfur import, phosphoric acid production and consumption of electric energy were the stages with the most significant environmental impacts. The diagnosis allowed that technological arrangements conceived under the environmental perspective were modeled. Therefore there were proposed improvements concerning the logistic of Sulphur transportation, water consumption in the industrial complex, and to the electricity acquired from the concessionaire. The study concludes that if the sulphur importation were shared among different suppliers, without considering Russia the most important of them nowadays , the environmental performance of the process would be positively affected. Regarding water consumption, the implementation of recycling actions brought gains in terms of water depletion, Eutrophication and both Freshwater and Terrestrial Ecotoxicity. Event that these results could be previously predicted the magnitudes of the decreases were expressive. However, the use of quicklime to neutralize the effluent in the wastewater treatment increased significantly the impacts as Climate Changes. The alternative of energy supplying electricity by cogeneration of biomass will be environmentally effective if it can provide, simultaneously reduction of thermal energy demand from fossil fuels.
259

Life-Cycle Benefit-Cost Analysis of Safety Related Improvements on Roadways

Frustaci, Jordan Browne 01 December 2016 (has links)
The Highway Safety Manual (HSM) lists four different methods for determining the change in crash frequency in order of reliability. Currently, the Utah Department of Transportation (UDOT) uses the fourth reliable method. The goal of this research was to develop a tool that the most reliable method mentioned in the HSM could be used to perform life-cycle benefit-cost analyses. A spreadsheet program was built that performs the HSM's Part C Predictive Method for 11 different roadway segment types mentioned in HSM using Excel macros and Visual Basic for Applications (VBA) programming. Intersections were not included in this spreadsheet program as they were not included in the Utah Crash Prediction Model (UCPM) or the Utah Crash Severity Model (UCSM) at the time of this research. The methodology for analysis was set up to become part of the use of the models in selecting countermeasures. The concept and spreadsheet layout are discussed using the rural two-lane two-way (TLTW) highway spreadsheet as an example. Three examples are presented in this thesis, which are a case of rural TLTW highway, a case of five-lane urban arterial with a two-way left-turn lane (TWLTL), and a case of a freeway segment, each with two selected countermeasures to compare their benefit-cost ratios (BCRs). One important aspect associated with life-cycle benefit-cost analysis of safety related improvements is the cost of countermeasures. The spreadsheets developed in this research can predict the benefits associated with a countermeasure following the methods found in the HSM; however, it does not include a module to estimate costs associated with a countermeasure to be selected because costs of countermeasures are dependent on the way such improvements are included in construction contracts. The engineer should seek guidance from the cost estimate expert within the agency or outside consultants when determining the project costs.
260

Meeting the ageing aircraft challenge

Crowley, Christopher Keith, Aerospace, Civil & Mechanical Engineering, Australian Defence Force Academy, UNSW January 2004 (has links)
&quotMeeting the ageing aircraft challenge&quot is not just about safety, not just about effectiveness, and not just about economy of support. It is about proactive and reactive optimization of all three service goals throughout long life cycles that span 20 or 30 years, or more, and typically, beyond the originally intended design life. It is therefore about organizational attitudes towards ongoing trend analysis and condition monitoring, and pervading cost benefit assessments of all forms of human innovation across what the author describes as 'the eight sustaining disciplines for long aerospace life cycles', including scientific and technological developments, and opportunities for reliability growth or 'refresh'. Complacency is the root cause of all problems with the design, maintenance and support of all modern infrastructure, and therefore life cycle planners and minders are required to be an enthusiastic but nervous lot - always hoping for the best, but planning for the worst impact of 'Mr Murphy'. Murphy thrives on complacency, is in bed with uncertainty, and never forgets (as we do often) that imperfection (no matter how small) breeds unreliability traps that patiently wait to surprise at some stage along the life cycle journey. He has the upper hand. ...Our best weapons against Murphy are continual, total picture and longer-term situational awareness; caution, vigilance, innovation and collaboration. This research study and thesis is intended as a broad and comprehensive management philosophy, a guide and checklist - a broad scrape of everything 'so deep', rather than coverage of any one-niche aspect of the ageing aircraft challenge in great depth. It includes a brief and simple strategic setting for Australian Military Aerospace requirements, and spans a three axes management philosophy: 1. a toolbox of eight sustaining disciplines, 2. trend analysis and 3. time-cost-benefit assessment. Along with complacency, the prime ageing aircraft 'killers' are identified, as are the key ageing aircraft 'age multipliers'. The eight sustaining disciplines are explained in varying depth, according to their broad significance to the ageing aircraft condition and life cycle. The ever-ubiquitous bathtub reliability curve - the key to understanding, predicting and controlling life cycle behaviour (including costs) - is emphasized. Engineering life cycle minding and capability management are broad focus areas. The eight areas of attention identified for this broad study are: 1. Aerospace design requirements and trends, 2. Science and technology opportunities, 3. Airworthiness, engineering and maintenance philosophy, 4. Reliability behaviour, 5. Operational use and abuse patterns, 6. Logistics support and managing obsolescence, 7. Technical workforce and organizational attitudes (requirements and outlook), and 8. Life cycle costing and budgeting. This thesis primarily draws attention to the fundamental driver of life cycle behaviour - reliability. The critical dependency that life cycle control and prediction has on consistent and high quality trend data collection and analysis is emphasized throughout, and the now pressing need for better identification of ageing aircraft cost growth drivers, and their containment, is linked to reliability trend awareness, manipulation and intervention. The human dimension is included - including coverage of organizational attitudes and what it takes to be a 'high reliability organization'. There are no magic or easy answers to the ageing aircraft condition and challenge. Trend analysis has to be done from the bottom up, system by system, for each fleet type. But over time, with consistent trend data collection, patterns emerge within the sophisticated and stochastic systems behaviour that that ageing aircraft play out. These patterns enable ongoing management of the long life cycle to be more confidently predicted, more assured and with best possible cost growth containment. The best, perhaps only, path to least surprises and best cost containment is now being re-identified in some military aviation organizations as a mature and evolving RAM engineering and RCM framework. RAM-RCM may well be the only recovery from what some admit is a death spiral of ageing aircraft cost growth.

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