L'effet protecteur de la circoncision masculine (CM) contre l'acquisition hétérosexuelle du VIH chez les hommes a été démontré dans trois essais contrôlés randomisés menés en Afrique australe et de l'Est, et sa généralisation a été recommandée par l’OMS et l’ONUSIDA comme une composante complémentaire importante des stratégies de prévention du VIH dans les pays à forte incidence du virus et bas taux de CM. Cependant, la généralisation de la CM dans les communautés ou elle n’est pas une norme sociale pose de nombreux défis en ce qui concerne son acceptabilité, son implémentation, son acceptation et son impact sur les comportements sexuels ainsi que sur les connaissances, attitudes et pratiques concernant la CM. Le projet ANRS 12126 Bophelo Pele a été implémenté à la suite des recommandations internationales dans la communauté d’Orange Farm, en Afrique du Sud, site du premier essai randomisé contrôlé sur la CM, et communauté cible de cette stratégie. Les activités de recherche menées au sein du projet prouvent que la généralisation de la CM est acceptable et réalisable rapidement dans une communauté à ressources limitées, selon les directives des instances internationales, de manière sure et coût-efficace. Son acceptation parmi les hommes non-circoncis est satisfaisante. De plus, trois ans après l’implémentation du projet, et bien que les connaissances envers la CM et son effet sur le risque du VIH restent à être améliorées, aucune différence de comportement sexuel n’a été décelée entre les hommes circoncis et les hommes non-circoncis ainsi qu’entre les partenaires des hommes circoncis et celles des hommes non-circoncis. La CM comme méthode de prévention du VIH dans les communautés hyperendémiques est donc une stratégie qui promet d’avoir un impact considérable sur l’épidémie en Afrique australe et de l’Est. / The protective effect of male circumcision (MC) on HIV heterosexual acquisition among men was demonstrated in three randomized controlled trials conducted in Southern and Eastern Africa, and its roll-out has been recommended by the WHO and UNAIDS as an important complementary component of HIV prevention strategies in high incidence communities with low rates of MC. However, the scale-up of MC in communities where it is not a social norm raises several challenges in regards to its acceptability, its implementation, its uptake, and its impact on sexual behavior as well as knowledge, attitudes and practices about MC. The ANRS 12126 Bophelo Pele project was implemented following the international recommendations in the community of Orange Farm (South Africa), site of the first MC randomized controlled trial, and target community of this strategy. Research activities conducted to evaluate the project show that the roll-out of MC is acceptable and can be implemented quickly in limited resources settings according to international recommendations in a safe and cost-effective manner. MC uptake among uncircumcised men is satisfactory. In addition, three years after project implementation, no difference in sexual behavior between circumcised men and uncircumcised men and between female partners of circumcised and uncircumcised men was detected, although knowledge and attitudes about MC and its association with HIV could be improved. MC as an HIV prevention method in hyperendemic communities is a promising strategy which can have a considerable impact on the epidemic in Eastern and Southern Africa.

Production planning problems are of paramount importance within supply chain planning, supporting decisions on the transformation of raw materials into finished products. Lot sizing in production planning refers to the tactical/operational decisions related to the size and timing of production orders to satisfy a demand. The objectives of lot-sizing problems are generally economical-related, such as saving costs or increasing profits, though other aspects may be taken into account such as quality of the customer service and reduction of inventory levels. Lot-sizing problems are very common in production activities and an efficient planning of such activities gives the company a clear advantage over concurrent organizations. To that end it is required the consideration of realistic features of the industrial environment and product characteristics. By means of mathematical modelling, such considerations are crucial, though their inclusion results in more complex formulations. Although lot-sizing problems are well-known and largely studied, there is a lack of research in some real-world aspects. This thesis addresses two main characteristics at the lot-sizing context: (a) setup crossover; and (b) perishable products. The former allows the setup state of production line to be carried over between consecutive periods, even if the line is not yet ready for processing production orders. The latter characteristic considers that some products have fixed shelf-life and may spoil within the planning horizon, which clearly affects the production planning. Furthermore, two types of perishable products are considered, according to the duration of their lifetime: medium-term and short-term shelf-lives. The latter case is tighter than the former, implying more constrained production plans, even requiring an integration with other supply chain processes such as distribution planning. Research on stronger mathematical formulations and solution approaches for lot-sizing problems provides valuable tools for production planners. This thesis focuses on the development of mixed-integer linear programming (MILP) formulations for the lot-sizing problems considering the aforementioned features. Novel modelling techniques are introduced, such as the proposal of a disaggregated setup variable and the consideration of lot-sizing instead of batching decisions in the joint production and distribution planning problem. These formulations are subjected to computational experiments in state-of-the-art MILP-solvers. However, the inherent complexity of these problems may require problemdriven solution approaches. In this thesis, heuristic, metaheuristic and matheuristic (hybrid exact and heuristic) procedures are proposed. A lagrangean heuristic addresses the capacitated lot-sizing problem with setup carryover and perishable products. A novel dynamic programming procedure is used to achieve the optimal solution of the uncapacitated single-item lot-sizing problem with setup carryover and perishable item. A heuristic, a fix-and-optimize procedure and an adaptive large neighbourhood search approach are proposed for the operational integrated production and distribution planning. Computational results on generated set of instances based on the literature show that the proposed methods yields competitive performances against other literature approaches. / Problemas de planejamento da produção são de suma importância no planejamento da cadeia de suprimentos, dando suporte às decisões da transformação de matérias-primas em produtos acabados. O dimensionamento de lotes em planejamento de produção é definido pelas decisões tático-operacionais relacionadas com o tamanho das ordens de produção e quando fabricá-las para satisfazer a demanda. Os objetivos destes problemas são geralmente de cunho econômico, tais como a redução de custos ou o aumento de lucros, embora outros aspectos possam ser considerados, tais como a qualidade do serviço ao cliente e a redução dos níveis de estoque. Problemas de dimensionamento de lotes são muito comuns em atividades de produção e um planejamento eficaz de tais atividades, estabelece uma clara vantagem à empresa em relação à concorrência. Para este objetivo, é necessária a consideração de características realistas do ambiente industrial e do produto. Para a modelagem matemática do problema, estas considerações são cruciais, embora sua inclusão resulte em formulações mais complexas. Embora os problemas de dimensionamento de lotes sejam bem conhecidos e amplamente estudados, várias características reais importantes não foram estudadas. Esta tese aborda, no contexto de dimensionamento de lotes, duas características muito relevantes: (a) preservação da preparação total e parcial; e (b) produtos perecíveis. A primeira permite que o estado de preparação de uma linha de produção seja mantido entre dois períodos consecutivos, mesmo que a linha de produção ainda não esteja totalmente pronta para o processamento de ordens de produção. A ultima característica determina que alguns produtos tem prazo de validade fixo, menor ou igual do que o horizonte de planejamento, o que afeta o planejamento da produção. Além disso, de acordo com a duração de sua vida útil, foram considerados dois tipos de produtos perecíveis: produtos com tempo de vida de médio e curto prazo. O ultimo caso resulta em um problema mais apertado do que o anterior, o que implica em planos de produção mais restritos. Isto pode exigir uma integração com outros processos da cadeia de suprimentos, tais como o planejamento de distribuição dos produtos acabados. Pesquisas sobre formulações matemáticas mais fortes e abordagens de solução para problemas de dimensionamento de lotes fornecem ferramentas valiosas para os planejadores de produção. O foco da tese reside no desenvolvimento de formulações de programação linear inteiro-mistas (MILP) para os problemas de dimensionamento de lotes, considerando as características mencionadas anteriormente. Novas técnicas de modelagem foram introduzidas, como a proposta de variáveis de preparação desagregadas e a consideração de decisões de dimensionamento de lotes ao invés de decisões de agrupamento de ordens de produção no problema integrado de planejamento de produção e distribuição. Estas formulações foram submetidas a experimentos computacionais em MILP-solvers de ponta. No entanto, a complexidade inerente destes problemas pode exigir abordagens de solução orientadas ao problema. Nesta tese, abordagens heurísticas, metaheurísticas e matheurísticas (híbrido de métodos exatos e heurísticos) foram propostas para os problemas discutidos. Uma heurística lagrangeana aborda o problema de dimensionamento de lotes com restrições de capacidade, preservação da preparação total e produtos perecíveis. Um novo procedimento de programação dinâmica e utilizado para encontrar a solução ótima do problema de dimensionamento de lotes de um único produto perecível, sem restrições de capacidade e preservação da preparação total. Uma heurística, um procedimento x-and-optimize e uma abordagem por buscas adaptativas em grande vizinhanças são propostas para o problema integrado de planejamento de produção e distribuição. Resultados computacionais em conjuntos de instâncias geradas com base na literatura mostram que os métodos propostos obtiveram performances competitivas com relação a outras abordagens da literatura.

Sinkholes are hazardous to buildings and their occupants, so a sensing device that can monitor underground changes is vital. Void Technology, developed in the Research and Development Center at Western Kentucky University, is creating a device that can improve monitoring for any movement underground. This device, created by Void Technology, is equipped with ESP8266, which is a Wi-Fi module that can send its information to the router in a wireless network. The focus of this thesis is on designing and developing an IOS framework application to show the signal strength capabilities in different buildings to find the optimum placement of the Void Technology devices. Each building, based on various construction materials, had different attenuations that could cause signal loss from the application to the ESP82266. The optimum place was found with this designed application. From this test experiment, it can be concluded that the application can show the signal strength based dBm. Thus, this new application is cost-effective as well as user friendly and which can help both the installer and homeowner to find the best position for installing The Void Technology with optimum signal strength.

The study improved the overall equipment effectiveness (OEE) of machines and processes through the implementation of a total productive maintenance (TPM) approach at Company S over a three-month period. By comparing the OEE of equipment before and after the implementation of autonomous maintenance, this study concluded that autonomous maintenance improves OEE. The target of this study was one general product line at a polytetrafluoroethylene (PTFE) plant. Due to time limitations, the study only applied autonomous maintenance to operational activities. This research involved machine and processes selection, condition assessment, baseline OEE assessment, operator training, execution of autonomous maintenance, and OEE measurement. The approach was based on the steps of autonomous maintenance but was simplified for the conditions of the plant.

Simple Temporal Networks (STNs) were introduced by Tsamardinos (2002) as a means of describing graphically the temporal constraints for scheduling problems. Since then, many variations on the concept have been used to develop and analyze algorithms for multi-agent robotic scheduling problems. Many of these algorithms for STNs utilize a flexibility metric, which measures the slack remaining in an STN under execution. Various metrics have been proposed by Hunsberger (2002); Wilson et al. (2014); Lloyd et al. (2018). This thesis explores how adequately these metrics convey the desired information by using them to build a reward function in a reinforcement learning problem.

Organizations around the world have attempted to implement the concepts of the Toyota Production System (TPS), commonly referred to as Lean, with limited sustainable success. The central principles of TPS, continuous improvement and respect for people, are grounded in the Japanese values of Monozukuri and Hitozukuri. Monozukuri deals with creating or making a product, while Hitozukuri conveys the idea of developing people through learning. In order for organizations to adopt these values they must have a system that engages employees at all levels in applying problem solving to improve their work. This research uses organizational assessments obtained from a variety of organizations implementing the lean approach using the Monozukuri and Hitozukuri values, referred to as the True Lean System (TLS). This research uses an inductive research approach to identify and analyze factors that impact the use of problem solving within organizations implementing a TLS. First, the qualitative assessment data is studied using textual analysis to identify themes impacting TLS. This analysis identified three topics as the highest weighted themes: number of problem solving methods, standardization, and employee roles. This qualitative data is then transformed using an integrated design model to systematically code the information into quantitative numerical data. Finally, this data was analyzed statistically by logistic regression to identify the factors impacting the use of problem solving within these organizations. The results from the logistic regression suggest that the most successful problem solving organizations have established standards for work and training employees; as well as, a single problem solving method that all employees use when identifying and implementing continuous improvement ideas. Which leads to the conclusion, in order for an organization to sustain the concepts of TPS, there must be a focus on defining clear standardized work, training, and the implementation of a single problem solving method.

The operating room (OR) is accountable for most hospital admissions and is one of the most cost and work intensive areas in the hospital. From recent trends, we discover an unexpected parallel increase in expenditure and waiting time. Therefore, improving OR planning has become obligatory, particularly regarding utilization, and service level. Significant challenges in OR planning are the high variations in demand, processing times of surgical specialties, the trade-off between the objectives, and control of OR performance in long-term. Our model provides OR configurations at a strategical level of OR planning to minimize the tradeoff between the utilization and service level accounting for variation in both demand and processing times of surgical specialties. An adaptive control scheme is proposed to aid OR managers to maintain the OR performance within the prescribed controllable limits. Our model is validated using a simulation of demand and processing time data of surgical services at University of Kentucky Health Care.

Businesses with global supply chains typically have a minimum of 1 interruption to their supply chain annually, which can decrease profitability and affect overall company performance. The purpose of this multiple case study was to explore strategies personal care business supply chain managers used to mitigate supply chain disruption risk. The targeted population was 9 supply chain managers working in 5 different Fortune 500 consumer packaged goods personal care companies in the northeastern United States who have successfully used strategies to mitigate supply chain disruptions. Corporate risk management was used as the conceptual framework of the study to determine how company leaders plan for supply chain disruptions and how leaders prioritize and resource implementation and assessment of these plans. Data collection included semistructured interviews, with review of each company's documents as the secondary source of data. Data were analyzed using thematic analysis. Two main themes emerged: identification of a qualified alternative supplier is a common strategy in supply chain disruption mitigation plans, and business top management support is essential in the execution of supply chain disruption plans and strategies. Results of this study might contribute to social change by empowering supply managers to make alternative choices relative to suppliers that will make products more affordable to consumers. An empowered supply management team leads to high return of investments for companies, which can support employment and additional tax revenue to support social programs.

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Bike Sharing is a sustainable mode of urban mobility, not only for regular commuters but also for casual users and tourists. Free-floating bike sharing (FFBS) is an innovative bike sharing model, which saves on start-up cost, prevents bike theft, and offers significant opportunities for smart management by tracking bikes in real-time with built-in GPS. Efficient management of a FFBS requires: 1) analyzing its mobility patterns and spatio-temporal imbalance of supply and demand of bikes, 2) developing strategies to mitigate such imbalances, and 3) understanding the causes of a bike getting damaged and developing strategies to minimize them. All of these operational management problems are successfully addressed in this dissertation, using tools from Operations Research, Statistical and Machine Learning and using Share-A-Bull Bike FFBS and Divvy station-based bike sharing system as case studies.