Tradeoff studies are a common part of engineering practice. Designers conduct tradeoff studies in order to improve their understanding of how various design considerations relate to one another. Generally a tradeoff study involves a systematic multi-criteria evaluation of various alternatives for a particular system or subsystem. After evaluating these alternatives, designers eliminate those that perform poorly under the given criteria and explore more carefully those that remain. The capability to compose preexisting tradeoff studies is advantageous to the designers of engineered systems, such as aircraft, military equipment, and automobiles. Such systems are comprised of many subsystems for which prior tradeoff studies may exist. System designers conceivably could explore system-level tradeoffs more quickly by leveraging this knowledge. For example, automotive systems engineers could combine tradeoff studies from the engine and transmission subsystems quickly to produce a comprehensive tradeoff study for the power train. This level of knowledge reuse is in keeping with good systems engineering practice. However, existing procedures for generating tradeoff studies under uncertainty involve assumptions that preclude engineers from composing them in a mathematically rigorous way. In uncertain problems, designers can eliminate inferior alternatives using stochastic dominance, which compares the probability distributions defined in the design criteria space. Although this is well-founded mathematically, the procedure can be computationally expensive because it typically entails a sampling-based uncertainty propagation method for each alternative being considered. This thesis describes two novel extensions that permit engineers to compose preexisting subsystem-level tradeoff studies under uncertainty into mathematically valid system-level tradeoff studies and efficiently eliminate inferior alternatives through intelligent sampling. The approaches are based on three key ideas: the use of stochastic dominance methods to enable the tradeoff evaluation when the design criteria are uncertain, the use of parameterized efficient sets to enable reuse and composition of subsystem-level tradeoff studies, and the use of statistical tests in dominance testing to reduce the number of behavioral model evaluations. The approaches are demonstrated in the context of a tradeoff study for a motor vehicle.

ix, 88 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / This dissertation addresses the high disease burden in developing countries today by examining the role of disease in economic development through its impact on productivity, fertility and human capital investment. In the second chapter of this dissertation, I model the impact on labor productivity of a change in disease susceptibility that results from intellectual property rights (IPR) reform. I develop a North-South model in which the disease environments differ between the rich and poor countries, and individuals consume innovated health goods to avoid the cost (labor time lost) of getting a disease. Southern welfare is shown to increase with the imposition of IPR protection when health needs in the South differ sufficiently from those in the North, and when health goods are accessible (in terms of adequate health care infrastructure) and effective (in counteracting disease). In the third chapter of this dissertation, I model the impact of child disease burden on fertility and human capital investment. The fertility response to a decline in child mortality depends on the morbidity effect of the disease, the level of disease burden, and whether prevalence rates or case fatalities decline. Fertility rates follow mortality and morbidity, but since mortality and morbidity do not always move in the same direction, the fertility response may be dampened or non-monotonic. Using a 20-year panel data set on malaria prevalence for 44 countries in sub-Saharan Africa, I find empirical support for the cases defined by the model; changes in malaria prevalence affect fertility more in non-endemic areas, where cases are more severe and more fatal relative to endemic areas. Historical and biological evidence suggest a link between (infectious) diseases early in life and (non-infectious) diseases later in life. In Chapter IV I model this link using a three-period overlapping generations model in which childhood disease outcomes affect longevity. Simulations in a general equilibrium framework duplicate the defining characteristics of the epidemiological-demographic transition as it occurred in many industrialized countries: as disease declines parents engage in a quantity-quality tradeoff for children, longevity rises and population declines after an initial jump. This dissertation includes unpublished co-authored material. / Committee in charge: Shankha Chakraborty, Chairperson, Economics; Bruce Blonigen, Member, Economics; Peter Lambert, Member, Economics; Laura Leete, Member, Planriing Public Policy & Mgmt; Jean Stockard, Outside Member, Planning Public Policy & Mgmt

O objetivo principal do trabalho é analisar a resposta da estrutura de capital agregada das firmas brasileiras às oscilações de variáveis macroeconômicas. A partir da teoria do “Tradeoff”, o escudo de tributos provenientes da despesa financeira e os custos de falência surgiram como fatores importantes para a determinação da estrutura de capital, que busca maximizar o valor da firma, a partir da incorporação do benefício líquido entre esses fatores ao seu valor. Baseado nesse entendimento e aliado a conclusões de trabalhos recentes sobre a influência de fatores macroeconômicos nessa decisão de estrutura ótima, o trabalho busca entender os efeitos, de oscilações na taxa real de juros, no crescimento do PIB, na taxa real de inflação, na taxa de câmbio, no volume de recursos de bancos de fomento e no mercado de ações, nas decisões sobre financiamento das atividades de empresas no Brasil. Foram encontrados resultados significativos para as todas as variáveis macroeconômicas e, para esses resultados, foram apresentadas interpretações a luz das teorias de estrutura de capital existentes na literatura contemporânea em finanças. / This paper intent to analyze the response of firm’s capital structure to fluctuations at macroeconomic variables, in the Brazilian market. The Tradeoff theory introduced the concept that the balance between the tax shield from financial expenses and bankruptcy costs are relevant factors in the determination of Firm’s capital structure. This theory predicts that firms to maximize its value should incorporate the net benefit between these factors to their value. The paper seeks to understand and measure the impacts of oscillations in interest rate, GDP growth, inflation rate, exchange rate, participation of development banks and stock market fluctuations in the decisions about capital structure. The paper presents significant results for all macroeconomic variables and provide interpretations for these findings, based on the current development of capital structure theories.

O objetivo principal do trabalho é analisar a resposta da estrutura de capital agregada das firmas brasileiras às oscilações de variáveis macroeconômicas. A partir da teoria do “Tradeoff”, o escudo de tributos provenientes da despesa financeira e os custos de falência surgiram como fatores importantes para a determinação da estrutura de capital, que busca maximizar o valor da firma, a partir da incorporação do benefício líquido entre esses fatores ao seu valor. Baseado nesse entendimento e aliado a conclusões de trabalhos recentes sobre a influência de fatores macroeconômicos nessa decisão de estrutura ótima, o trabalho busca entender os efeitos, de oscilações na taxa real de juros, no crescimento do PIB, na taxa real de inflação, na taxa de câmbio, no volume de recursos de bancos de fomento e no mercado de ações, nas decisões sobre financiamento das atividades de empresas no Brasil. Foram encontrados resultados significativos para as todas as variáveis macroeconômicas e, para esses resultados, foram apresentadas interpretações a luz das teorias de estrutura de capital existentes na literatura contemporânea em finanças. / This paper intent to analyze the response of firm’s capital structure to fluctuations at macroeconomic variables, in the Brazilian market. The Tradeoff theory introduced the concept that the balance between the tax shield from financial expenses and bankruptcy costs are relevant factors in the determination of Firm’s capital structure. This theory predicts that firms to maximize its value should incorporate the net benefit between these factors to their value. The paper seeks to understand and measure the impacts of oscillations in interest rate, GDP growth, inflation rate, exchange rate, participation of development banks and stock market fluctuations in the decisions about capital structure. The paper presents significant results for all macroeconomic variables and provide interpretations for these findings, based on the current development of capital structure theories.

Made available in DSpace on 2014-06-12T17:41:43Z (GMT). No. of bitstreams: 2 arquivo7335_1.pdf: 977856 bytes, checksum: 83769c5348fede0c81ce7d8cd086c93c (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2006 / Neste trabalho são estudados 3 modelos. Aborda-se a questão da transposição do rio São Francisco por meio de dois modelos de crescimento econômico. Nestes, deseja-se maximizar a utilidade de um trabalhador médio. As principais variáveis em estudo são a água não energética, as energias hidrelétrica e termelétrica, e o déficit energético. É por meio das relações entre estas variáveis que se estuda o tradeoff água £ energia, que engloba o problema da transposição. No segundo modelo, a energia térmica é agregada à hidráulica, tornando-se uma fração desta última. Isto permite que se perceba com maior clareza as implicações das decisões de expansão do sistema elétrico, decorrentes da escolha entre termeletricidade e hidreletricidade. O modelo seguinte trata da operação do sistema elétrico, onde se deseja minimizar os custos pela decisão da energia gerada em cada usina do sistema, considerando que o custo de um déficit energético representa para a economia. Este modelo é baseados no NEWAVE, modelo utilizado pelo Operador Nacional do Sistema, com este mesmo objetivo de minimização do custo operacional. Por meio da Teoria de Controle Ótimo obtém-se relações entre as variáveis em estudo. Entre os principais resultados deste trabalho destaca-se o fato de a água, enquanto insumo produtivo não energético, dar uma maior contribuição à economia do que a água utilizada na geração hidrelétrica. A água não energética torna-se ainda mais importante em um cenário de déficit energético, ou, no caso de expansão da matriz energética pelo aumento da geração termelétrica

The major components of the tracheal system of insects are an extension of the exoskeleton, and the size of the exoskeleton is fixed in the adult stage, so any increase in metabolic demand that may accompany reproduction must be met by a relatively unaltered tracheal system that the female set in place at ecdysis, when entering adulthood. Acute hypoxia tends to elicit an increase in ventilation in insects, and here, I observe increased interburst VCO2 release, and a tendency towards a more continuous gas exchange pattern being preferred over discontinuous gas exchange when Blaptica dubia and Eublaberus posticus are exposed to a descending regime of hypoxia. Additionally, higher temperatures appear to increase sensitivity to hypoxia in these species, an expected result because both species, like most ectothermic animals, display a Q10 effect, increasing metabolic rates as temperature increases. The reproductive mode of B. dubia is considered to be lecithotrophic pseudoviviparity (or type A ovoviviparity), and by the time the embryos are born, they have more than doubles in volume from the time of oviposition. This gain is apparent in the wet mass of the embryo, with no change occurring in dry mass. The egg mass that can be attributed to water begins at 39% at oviposition and increased to nearly 82% at hatching. The metabolic rates of females and embryos increase as embryonic development progresses, but bomb calorimetry reveals that energy content of the embryos does not change. It is possible that these embryos gain some nutrition from the mother during embryonic development, but direct evidence remains to be demonstrated. Blaptica dubia and Eublaberus posticusare both blaberid species that display the same reproductive mode, pseudoviviparity, with incubation occurring in a brood sac. Comparisons between the reproductive traits of B. dubia and E. posticus reveal that the two species have similar reproductive periods, interbirth periods, and clutch sizes to one another, and that both have reproductive cycles and incubation times intermediate to oviparous species and the one species of cockroach that some consider to be truly viviparous (Diploptera punctata). However, whereas adult female E. posticus are larger than female B. dubia (E. posticus non-gravid female mass: 2.91 +/- 0.42 g, 20; B. dubia non-gravid female mass: 2.60 +/- 0.40 g, 20), the offspring of B. dubia are larger than those of E. posticus at the time of birth (B. dubia neonate mass: 24.70 +/- 4.01 mg, 19; E. posticus neonate mass: 22.40 +/- 1.36 mg, 19). Both gravid and non-gravid female B. dubia respond similarly to acute hypoxia exposure, increasing mean total VCO2. However, the reproductive state does not appear to exacerbate, nor dull, the acute response to hypoxia. Gravid and non-gravid female B. dubia were exposed to chronic hypoxia for 30 days and 45 days. Relatively high mortality was observed in nearly all chronic hypoxic treatment groups as compared to controls at 21 kPa O2. Comparing treatment groups to controls maintained at 21 kPa O2, embryo mass was not decreased, nor was embryo VCO2 at day 30. Adult female B. dubia metabolic rates did not show a consistent change in response to chronic hypoxia, but decreased metabolic rate was observed in the non-gravid B. dubia exposed to chronic 4 kPa O2, an observation that is consistent with past studies in insects. Survival rates were lower for both gravid and non-gravid females in 4, 8, and 12 kPa O2, as well as in 15 kPa O2 in gravid females, as compared to 21 kPa O2. Gravid females experiences a decreased survival rate compared with non-gravid females at 12 and 15 kPa O2, but gravid and non-gravid females had similarly low survival rates at 4 and 8 kPa O2. This difference in survival rates suggests there is a cost associated with carrying an ootheca in a brood sac, resulting in an increased sensitivity to hypoxia, at least over a long period of time.

The geographic mosaic theory of coevolution predicts that spatial differences in species interactions result in a patchwork of evolutionary hot and cold spots across a landscape. We used horsenettle (Solanum carolinense L.), a perennial weed with a diverse insect community found in old fields and meadows, to examine local adaptation and resource-mediated selection. The goals of this study were to (1) determine the potential for a selection mosaic by identifying local adaptation through trait-interaction matching with herbivores, pollinations and plant competitors, and (2) determine the potential for indirect selection through resource allocation tradeoffs. The potential for local adaptation was determined by measuring interactions in four populations and relating those findings to plant traits measured on offspring grown from those populations in a ‘common garden.’ Allocation tradeoffs between growth, herbivore resistance, and floral traits were also assessed in the common garden. We found high herbivore damage in the field associated with decreased root:shoot ratios in greenhouse-grown plants, which may indicate an herbivore-mediated effect on life-history through selection for a more annual strategy. By examining allocation tradeoffs we found evidence of two distinct reproductive strategies in this perennial plant. Negative correlations between reproductive traits and both growth and defense suggest that individuals either favor current growth and reproduction over defense, or invest in current survival and defense while delaying reproduction. Overall, this study sheds light on how selection changes over space and time, which are of many of the fascinating traits we find in plants and animals today.

No description available.

This article examines the often studied guns vs. butter tradeoff within the context of federal military spending and means-tested social welfare spending in an effort to focus academic attention on the impact of military expenditure on America’s poorest populations. Using OLS regression on federal budgetary data ranging from 1962 to 2020, I test for a tradeoff between military spending as a proportion of the discretionary budget and means-tested welfare spending as a proportion of the mandatory budget. I also include several covariates that previous literature has shown to be relevant to a potential tradeoff — including war status, poverty rate, unemployment rate, economic growth, inequality, and legislator ideology — to determine whether they play a mediating role between military and means-tested welfare spending. I also conduct a qualitative analysis of platforms published by the Democratic and Republican parties during select election years between 1940 and 2020 in order to find a causal mechanism for a budgetary tradeoff. These analyses conclude that there is significant statistical evidence of a tradeoff between these two spending categories, and that party attitudes about who/what is more deserving of federal funding — which are consistently expressed by each party throughout the 80-year period — provide a causal mechanism for such a tradeoff. These attitudes, which are constructed through the priorities expressed in platforms over time, cause legislators to provide funding to groups (either the military or the American poor) that they find deserving, and subtract funding from those they find undeserving. In finding that military expenditure directly undermines life-saving assistance, this article encourages greater study of how seemingly unrelated budgetary decisions (especially those relating to national defense) may play an active role in America’s worsening inequality crisis.

<p dir="ltr">This work provides a new framework for investigating instances where multitasking and focusing do not need to trade off, but can rather coexist.</p>