In this thesis, we study robust combinatorial problems with interval data. We introduce several new measures of robustness in response to the drawbacks of existing measures of robustness. The idea of these new measures is to ensure that the solutions are satisfactory for the decision maker in all scenarios, including the worst case scenario. Therefore, we have introduced a threshold over the worst case costs, in which above this threshold, solutions are no longer satisfactory for the decision maker. It is, however, important to consider other criteria than just the worst case. Therefore, in each of these new measures, a second criteria is used to evaluate the performance of the solution in other scenarios such as the best case one. We also study the robust deviation p-elements problem. In fact, we study when this solution is equal to the optimal solution in the scenario where the cost of each element is the midpoint of its corresponding interval. Then, we finally formulate the robust combinatorial problem with interval data as a bicriteria problem. We also integrate the decision maker's preferences over certain types of solutions into the model. We propose a method that uses these preferences to find the set of solutions that are never preferred by any other solution. We call this set the final set. We study the properties of the final sets from a coherence point of view and from a robust point of view. From a coherence point of view, we study necessary and sufficient conditions for the final set to be monotonic, for the corresponding preferences to be without cycles, and for the set to be stable. Those that do not satisfy these properties are eliminated since we believe these properties to be essential. We also study other properties such as the transitivity of the preference and indifference relations and more. We note that many of our final sets are included in one another and some are even intersections of other final sets. From a robust point of view, we compare our final sets with different measures of robustness and with the first- and second-degree stochastic dominance. We show which sets contain all of these solutions and which only contain these types of solutions. Therefore, when the decision maker chooses his preferences to find the final set, he knows what types of solutions may or may not be in the set. Lastly, we implement this method and apply it to the Robust Shortest Path Problem. We look at how this method performs using different types of randomly generated instances.

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It has been reported that minimum quantity lubrication (MQL) provides better tool life compared to flood cooling under some drilling conditions. In this study, I evaluate the performance of uncoated HSS twist drill when machining AISI 1018 steel using a newly developed lubricant designed for MQL (EQO-Kut 718 by QualiChem Inc.). A randomized factorial design was used in the experiment. The results show that a tool life of 1110 holes with a corresponding flank wear of 0.058 mm was realized.

Much debate surrounds the effect the minimum wage has on employment. Economic theory suggests that the minimum wage acts as a price floor in the labor market and thus leads to disemployment. However, empirical evidence from a variety of industries, states, and age groups suggests that the minimum wage has negative, negligible, and even positive effect on employment. This Economics/Public Policy Analysis thesis is the first study to analyze the effect the minimum wage has on employment in the informal sector. I apply four OLS regressions with various levels of specifications on five dependent variables: hourly wage, log hourly wages, hours worked, log daily income, and percentage working. My results suggest that economic theory holds true in the informal sector with regards to the California minimum wage mandate of 2016: the minimum wage had a positive and statistically significant effect on hourly wage, with average hourly wages increasing by $1.88; the minimum wage had a negative and statistically significant effect on percentage working, with average number of workers dispatched to jobs decreasing by 15%.

Este trabalho busca compreender como o governo do presidente Eurico Gaspar Dutra (vigorou de 31 de janeiro de 1946 a 31 de janeiro de 1951) fez uso dos instrumentos de política econômica acerca da renda e do salário mínimo, bem como seus reflexos nas questões do trabalho, do trabalhador e nos meios de representação deste. O governo do Presidente Eurico Gaspar Dutra é normalmente conhecido como o governo entre os governos de Getúlio Vargas e talvez, por isso, é pouco estudado pela academia, diferente de seu antecessor-sucessor. Busca-se neste trabalho contribuir para a pesquisa do governo Dutra que, apesar de considerado um interregno entre os governos de Getúlio Vargas, abandonou o varguismo e imprimiu uma política liberal e extremamente repressiva contra a classe trabalhadora, contribuindo para a perda de parte da renda do trabalhador brasileiro daquela época, com, talvez, reflexos em nossos dias. A política de arrocho salarial de Dutra foi um duro golpe contra os trabalhadores e em favor do capital. Os instrumentos de política econômica de Dutra são alvos de discussão no presente trabalho, com ênfase nas questões acerca do salário mínimo, situação do trabalhador e inflação. Questões estas praticamente atemporais na economia brasileira. / This paper seeks to understand how the government of President Eurico Gaspar Dutra (from January 31, 1946 to January 31, 1951) made use of the economic policy instruments on income and the minimum wage as well as its reflections on labor issues, of the worker and in the means of representing him. The government of President Eurico Gaspar Dutra is usually known as the government between the governments of Getúlio Vargas and, perhaps because of this, is little studied by the academy, different from its predecessor-successor The paper seeks to contribute to the research of the Dutra government which, although considered an interregnum between the governments of Getúlio Vargas, abandoned the \"varguismo\" and printed a liberal and extremely repressive policy against the working class, contributing to the loss of part of the income of the Brazilian worker of that time, with perhaps reflections in our day. Dutra\'s wage policy was a blow to the workers in favor of the capital. Dutra\'s economic policy instruments are the subject of discussion in this paper, with emphasis on issues such as the minimum wage, the worker\'s situation and inflation. These issues are practically timeless in the Brazilian economy.