Orientador: Roberto Testezlaf / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-06T12:49:54Z (GMT). No. of bitstreams: 1 Gomes_EderPereira_D.pdf: 2568175 bytes, checksum: 5e0ee1aa19ad6060b3562bc9ef0c7b3e (MD5) Previous issue date: 2005 / Resumo: A irrigação, na forma que vem sendo realizada na tomaticultura da região de Campinas, SP, tem proporcionado sérias restrições ambientais. O presente trabalho avaliou alternativas de mudanças tecnológicas na irrigação da tomaticultura da região de Campinas, buscando uma solução sustentável, viável economicamente e com eficiente uso da água, instalando em uma área experimental, diferentes sistemas de irrigação empregados na tomaticultura da região (sulcos, sulcos abastecidos por mangueira e gotejamento). As parcelas experimentais foram dispostas em delineamento de blocos ao acaso com quatro repetições. Comparou-se no experimento, a eficiência de uso da água, os parâmetros de eficiência e de uniformidade de irrigação, a produtividade e a qualidade dos frutos de tomate e o efeito de cada sistema de irrigação no valor da cobrança da água e no custo de produção. A irrigação por sulcos, por ser o sistema predominante na região, foi utilizada como testemunha (sem interferência no manejo de irrigação), enquanto os outros sistemas, foram avaliados como alternativas tecnológicas. Mediante os resultados obtidos pode-se afirmar que não houve diferenças significativas de produtividade entre os tratamentos, pois todos ofereceram condições ideais de umidade no solo. Entretanto, as eficiências de uso da água foram distintas, sendo iguais a 24,1 kg.m-3, 71,5 kg.m-3 e 112,8 kg.m-3, respectivamente para sulcos, sulcos abastecidos por mangueira e gotejamento. A irrigação por sulcos obteve baixa eficiência de aplicação, em torno de 28%, com perda por percolação profunda superior a 70%. Na irrigação por sulcos abastecidos por mangueira e gotejamento, os valores de eficiência de aplicação foram superiores, sendo iguais a 85% e 87,8%, respectivamente, com perdas por percolação menores, 15% e 12,2%, respectivamente. Em todos os sistemas de irrigação, a cobrança da água exerceu pouca influência no custo de produção, com valores iguais a 0,14% (R$40,80), 0,04% (R$13,32) e 0,03% (R$8,25), respectivamente para sulcos, sulcos abastecidos por mangueira e gotejamento. A irrigação por gotejamento elevou o custo de produção em 3,5% (+R$1041,89), enquanto a irrigação por sulcos abastecidos por mangueira reduziu o custo de produção em 1,1%(-R$330,08). Diante dos resultados, chegou-se à conclusão que a irrigação por sulcos abastecidos por mangueira é opção mais sustentável de mudança tecnológica, pois demandou menor investimento, diminuiu o custo de produção e o consumo de água, enquanto a irrigação por gotejamento contemplou somente o último aspecto, a redução do consumo de água / Abstract: Searching for a sustainable yield, economically viable and water efficient use, the objective of this study was to evaluate changes in irrigation technologies used in fresh-market-tomatoes crop. Three different irrigation systems (furrow, furrow supplied by hose and drip) were installed in the same farm to compare water application uniformity and efficiency, to estimate crop yield and fruits quality and to analyze its effects on water and production costs. The irrigation systems were select based upon the facts that furrow is a most utilized system in the region, the furrow supplied by hose and drip irrigation are recent alternatives market technologies for the farmers. The results showed no significant differences in yields and fruits qualities among the evaluated irrigation systems. The drip irrigation system showed higher water use efficiency. The furrow irrigation system showed application efficiency of around 28%, with deep percolation losses of 70%. The furrow supplied for hose and drip irrigations systems had applications efficiencies of 85% and 87.8%, respectively with deep percolation losses of 15% and 12.2%, respectively. In all the irrigation systems, the water cost had no significant effect the total production cost, representing only 0.14%, 0.05% and 0.03%, for furrow, furrow supplied by hose and drip irrigations systems, respectively. The change to drip irrigation system increased the production cost yield in 3.5%, while furrow supplied by hose reduced it in 1.1%. The furrow irrigation system supplied by hose showed the most sustainable technical option to change from the traditional furrow irrigation for the farmers, being able to reduce the production cost and the amount of water with less investment / Doutorado / Agua e Solo / Doutor em Engenharia Agrícola

A recém-adquirida competitividade pela energia eólica frente a outras fontes alternativas e, até mesmo, convencionais tem sido comemorada pelo setor de energia elétrica. No entanto, a base para essa comparação leva em conta apenas os parâmetros dos investimentos do parque viabilizado, não sendo considerados outros fatores inerentes à inserção da fonte na matriz, como, por exemplo, o aumento do risco ao sistema, investimento necessário à ampliação da Rede Básica para escoamento da energia para o centro de carga e os custos com redespacho de geração, reserva girante e controles do sistema. O maior potencial está concentrado no Nordeste e o maior centro de carga no Sudeste, assim, em caso de exploração intensiva do potencial da fonte, será necessário passar por grandes investimentos em reforços e ampliações da rede básica. A partir desse panorama, busca-se realizar as primeiras análises de sensibilidade sobre a eficiência econômica dos parques eólicos instalados no Nordeste e, ao mesmo tempo, analisar as condições de atendimento da ponta. / The newfound competitiveness in wind power compared to other alternative and even conventional energy sources has been celebrated by the electric power sector. However, the basis for this comparison takes into account only the parameters of the Capex, not considering other factors inherent in the insertion of the source in the array, for example, increase the risk to the system, expansion of the investment necessary for Basic network for transport of energy to the load center and the cost of redispatch generation, spinning reserve, and system controls. The greatest potential is concentrated in the Northeast and the largest load hub in the Southeast, so, in case of intensive exploitation of the potential of the source, large investments in reinforcements and expansions of the grid will be necessary. From this overview, we attempt the firsts sensitivity analysis on the economic efficiency of wind farms in the Northeast and the load peak supply conditions.

The study involves, describing the nature of the airline industry, especially in the African situation with some of its problems being high airfares and inaccessibility within the continent. In order to address these problems an analysis of the minimal operating costs and challenging factors affecting route costs needs to be carried out. The aim of the study was to develop from first principles, a cost model to calculate operating costs along any route in the African continent. The costing of an airline service is reviewed through existing literature and a compilation of the structure, components and their equations and default values was done. A model structure to calculate these operating costs on a route is set up, while data is analysed to provide inputs to the model. The model is then applied to carry out an analysis of the type of service provided in terms of costs and service quality. Africa specific data is then included in the model in terms of passenger trips and sector distances and these are embedded into the model. The main conclusion drawn from the study was that this model could be used to design optimally an airline service based on operating costs using existing passenger demand and sector distance. The model was applied to a route within Africa and results showing how smaller capacity aircraft even though limited by maximum range are the most economical to run along routes when the frequency of flights is high. / Dissertation (M Eng (Transportation Engineering))--University of Pretoria, 2006. / Civil Engineering / unrestricted

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 1979 / Bibliography: leaves 344-347. / by William M. Swan. / Ph. D. / Ph. D. Massachusetts Institute of Technology, Department of Aeronautics and Astronautics

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A robust algorithm has been developed to do data processing accurately, removing the need for a radio signal to be imbedded for locational accuracy. This, consequently eliminates the signposts installation and maintenance costs and worries. A sensitivity analysis of the algorithm using a real life data file revealed that the matching process change with changes in system parameters, adding credibility to the technique used for matching in the algorithm. Next, several new programs have been added to bring together a software package yielding management reports and plots. These reports and plots are tremendous decision aiding tools and since the programs are interactive, the package is easy to use. A user's manual has also been developed. Finally, an implementation of the Automated Data Acquisition System at TRT, Norfolk, is discussed. A systematic approach to the software development to meet the needs of the transit property has been conceptualized and specific software developed. A discussion of the details of this software development has been addressed, too. In essence, Automatic Data Acquisition systems research at Virginia Tech has now evolved to such a stage that with a little "tuning" of hardware & the associated software, a very powerful and versatile automated data collection and management aiding tool will be available for economical widespread implementation. / Master of Science

Thesis (MBA)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: The emergence of low cost airlines (LCAs) has attracted attention from passengers, competitors, the public, and researchers alike. It seems prodigious that LCAs prosper in today's time of economic downturn and are therefore able to counter the industry's trend. lATA's member airlines have accumulated losses of $31 billion since the beginning of the new millennium. Furthermore, industry icons such as American Airlines and British Airways are fighting for survival while some, namely Air Canada, are on the edge of bankruptcy: a fate which others, like Sabena, have not been able to escape. However, the low cost business model has triumphantly entered the aviation market since the deregulation of the markets in the U.S. in 1978. Low cost airlines like Southwest Airlines and Ryanair not only achieve double-digit profit margins, but also have the highest market capitalisation of the industry. This thesis examines the reason for the success of LCAs in the U.S. and EU. LCAs operate with a much lower cost base than most carriers, especially the major hut-and-spoke (H&S) airlines. The low cost business model aims at increasing both aircraft and staff productivity. It also simplifies the sequence of operations workflow and pricing structure. The thesis gives special consideration to the cost structure of LCAs. The advantages of LCAs lie within the areas such as labour, seat density, and distribution. The second objective of this thesis is to evaluate the development of LCAs and consider the implications for the European transport industry. Whereas American LCAs have operated for more than twenty-five years, the boom of their European counterparts did not commence until the end of the 1990s. Ryanair and easyJet have growth rates of more than thirty percent. The author agrees with the expectations of aviation experts that LCAs will grow until they serve approximately a quarter of the market; hence, the business model of low cost is sustainable. However, only three to four low cost airlines will survive the fierce competition in Europe. / AFRIKAANSE OPSOMMING: Die dringendheid van lae koste lugrederye (LKL'e) het die aandag getrek van passasiers, mededingers, die publiek en navorsers. Dit is vreemd dat LKL'e floreer in die huidige ekonomiese afswaai en gevolglik die tendens van die industrie teenwerk. Lugrederye, wat lid is van "lATA" , het sedert die begin van die eeu verliese gelei van 31 biljoen dollar. Daar teenoor is industriele ikone soos die Amerikaanse en Britse lugdienste (American Airlines and British Airways) besig om te veg vir oorlewing, terwyl ander soos die Kanadese lugdiens (Air Canada) op die grens van bankrotskap is: 'n ramp wat sommige soos Sabena nie kon vryspring nie. Sedert die deregulering van die lugvaart in die VSA in 1978 het die lae koste besigheidsmodel egter die mark triomfanlik betree. Lae koste lugrederye soos SuidWes lugdiens en Ryanair ervaar nie alleen dubbel-syfer wins-marges nie, maar het ook die hoogste mark-kapitalisasie in die industrie. Hierdie verhandeling ondersoek die redes vir die sukses van LKL'e in die V.SA en E.U. LKL'e werk teen 'n baie laer koste basis as die meeste vervoerders, veral die belangrikste "hub-and-spoke" lugrederye. Die doel van die lae koste besigheidsmodel is om beide die vliegtuie en die personeel se produktiwiteit te verhoog. Dit vereenvoudig ook die volgorde van prosedures, werkvloei en prysstruktuur. Hierdie verhandeling gee spesiale aandag aan die kostestruktuur van LKL'e. Die voordele van LKL'e lê op die gebied van arbeid, sitplekplasing en verspreiding. Die tweede doel van hierdie verhandeling is om die ontwikkeling van LKL'e te evalueer en te kyk na die invloed op die Europese vervoer-industrie. Die Amerikaanse LKL'e word reeds vir meer as vyf-en-twintig jaar bedryf terwyl hulle Europese eweknie nie 'n opswaai voor die einde van die 1990's ervaar het nie. Ryanair en easy Jet het 'n groei getoon van meer as 30%. Die argument is dat volgens lugvaartkundiges die LKL'e sal groei totdat dit ongeveer 'n kwart van die mark bedien; daarom sal die lae koste model die beste oorleef. Nogtans sal slegs drie of vier van die lae koste lugrederye egter die hewige kompetisie in Europa oorleef.

The deregulation of the airline industry created a myriad of changes in the U.S. air transport system that has both defended and sparked debate on the wisdom of such policy change for over three decades. One of the promises of deregulation from its proponents in the 1970s was increased competition that would lead to a reduction in fares for consumers. Historic data and literature has indeed shown this to be to the case as average airfares have trended downward especially over the last twenty years. Nonetheless, the industry has become much more complex since deregulation in terms of pricing to the point that very sophisticated yield management computer models are used to achieve an optimum balance between load factors and price. Consequently, this has in turn translated into a haphazard experience for most air travelers in the United States; for instance, the cost of a ticket is sometimes lower traveling from coast to coast than within a particular region of the U.S. and paid fares for the exact same trip can deviate dramatically, often based on variation in the date of purchase. Additionally, this has also resulted in a spatial pattern where certain regions throughout the country have enjoyed lower airfares more so than others. This research seeks to identify this regional disparity using a geographically weighted regression and spatial autoregressive models in a sample of 6,200 routes between 80 primary U.S. airports. The results from the global model showed that variables which measure competition (airlines), operating cost (flights, distance) and elasticity (layover time) proved to be statistically significant and had a positive relationship with airfare The GWR results indicated that while some factors like distance, and hub size, were statistically significant almost nationwide, other factors such as frequency, presence of low cost carriers, and numbers of airlines were only statistically significant at certain airports. Finally, the spatial regressions models indicate that the spatial autocorrelation found in U.S. airfares resemble the first order properties of spatial autocorrelation (i.e. spatial heterogeneity) and not the second order properties (i.e. spatial dependence). / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

This thesis addresses questions of how to incorporate quality of care, represented by disutility-bearing effects such as mortality, morbidity and re-admission, in measuring relative performance of public hospitals. Currently, case-mix funding and performance, measured with costs per case-mix adjusted separation, hold hospitals accountable for costs, but not effects, of care, creating economic incentives for quality of care minimising cost per admission. To allow an appropriate trade-off between the value and cost of quality of care a correspondence is demonstrated between maximising net benefit and minimising costs plus decision makers??? value of disutility events, where effects of care can be represented by disutility events and hospitals face a common comparator. Applying this correspondence to performance measurement, frontier methods specifying disutility events as inputs are illustrated to have distinct advantages over output specifications, allowing estimation of: 1. economic efficiency conditional on the value of avoiding disutility events. 2. technical, scale and congestion sources of net benefit efficiency; 3. best practice peers over potential decision makers??? value of quality; and 4. industry shadow price of avoiding disutility events. The accountability this performance measurement framework provides for effects and cost of quality of care are also illustrated as the basis for moving from case-mix funding towards a funding mechanism based on maximising net benefit. Links to evidence-based medicine in health technology assessment are emphasised in illustrating application of the correspondence to comparison of multiple strategies in the cost-disutility plane, where radial properties as shown to provide distinct advantages over comparison in the cost-effectiveness plane. The identified performance measurement and funding framework allows policy makers to create economic incentives consistent with evidence-based medicine in practice, while avoiding incentives for cream-skimming and cost-shifting. The linear nature of the net benefit correspondence theorem allows simple inclusion of multiple effects of quality, whether expressed as not meeting a standard, functional limitation or disutility directly. In applying the net benefit correspondence theorem to hospitals a clinical activity level is suggested, to allow correspondence conditions to be robustly satisfied in identification of effects with decision analytic methods, adjustment for within DRG risk factors and data linkage to effects beyond separation.