<p dir="ltr">Path-tracking control is an integral part of motion planning in autonomous vehicles, in which the vehicle's lateral and longitudinal positions are controlled by a control system that will provide acceleration and steering angle commands to ensure accurate tracking of longitudinal and lateral movements in reference to a pre-defined trajectory. Extensive research has been conducted to address the growing need for efficient algorithms in this area. In this dissertation, a scenario and machine learning-based data-driven control approach is proposed for a path-tracking controller. Firstly, a Deep Reinforcement Learning model is developed to facilitate the control of longitudinal speed. A Deep Deterministic Policy Gradient algorithm is employed as the primary algorithm in training the reinforcement learning model. The main objective of this model is to maintain a safe distance from a lead vehicle (if present) or track a velocity set by the driver. Secondly, a lateral steering controller is developed using Neural Networks to control the steering angle of the vehicle with the main goal of following a reference trajectory. Then, a path-planning algorithm is developed using a hybrid A* planner. Finally, the longitudinal and lateral control models are coupled together to obtain a complete path-tracking controller that follows a path generated by the hybrid A* algorithm at a wide range of vehicle speeds. The state-of-the-art path-tracking controller is also built using Model Predictive Control and Stanley control to evaluate the performance of the proposed model. The results showed the effectiveness of both proposed models in the same scenario, in terms of velocity error, lateral yaw angle error, and lateral distance error. The results from the simulation show that the developed hybrid A* algorithm has good performance in comparison to the state-of-the-art path planning algorithms.</p>

Variations can have substantially negative effects on performance and it is therefore important to investigate how the variations can be reduced or absorbed in an appropriate way for competitiveness. Manufacturing companies are daily exposed to variations and operations managers need to take capacity management decisions with this in mind to secure the delivery capability. The current body of knowledge mainly focus on techniques for root cause analysis for reducing variations, especially in the manufacturing processes, neglecting the fact that both internally and externally generated variations are more or less possible to affect. Buffers are traditionally associated with waste and unfavourable performance, while the right buffers can be of strategic importance. The purpose of this research is therefore to increase the understanding of causes for variations, actions to reduce variations and how buffers can be used to mitigate negative effects of variations related to capacity management in a manufacturing context. Three research studies have been conducted, including four appended papers, to fulfil the purpose. These studies encompassed different combinations of traditional literature reviews, conceptual research with logical reasoning and case study research. The findings demonstrate that working on mitigating negative effects of variations is a complex challenge and not just about choosing to reduce or absorb the variations. In general, it is concluded that the variation management and buffer management include several aspects to consider with implications for the capacity management. In addition, the results indicate that the decisions in manufacturing companies tend to be based on intuition and previous experience due to a lack of decision support. Furthermore, the participating companies perceive that several of their internal routines contribute to their prevailing variations. This research contributes to an awareness of causes for variations that are possible to affect, possible actions to reduce the variations and the purposes of different buffers to absorb variations. This is sought to facilitate a systematic way of working with reducing and absorbing variations, creating support in the variation management and the buffer management from a capacity management perspective. / Variationer kan medföra negativa effekter för en verksamhets prestation och det är därmed viktigt att utforska hur variationerna kan reduceras eller absorberas på lämpligt sätt för att verksamheten ska vara konkurrenskraftig. Tillverkande företag är dagligen exponerade för variationer och produktionschefer behöver beakta detta i kapacitetsadministrationen för att säkerställa leveransförmågan. Befintlig litteratur fokuserar främst på tekniker för att analysera grundorsaker inom tillverkningsprocesserna och ignorerar det faktum att både internt och externt genererade variationer är mer eller mindre påverkbara. Buffertar associeras traditionellt med oönskat slöseri fastän rätt buffertar kan vara av strategisk betydelse. Syftet med denna forskning är därmed att öka förståelsen för orsaker till variationer, åtgärder för att reducera variationer och hur buffertar kan tillämpas för att överkomma negativa effekter av variationer i relation till kapacitetsadministration inom en tillverkningskontext. Tre forskningsstudier, innefattande fyra publikationer, har genomförts för att uppfylla syftet. Dessa studier består av en kombination av traditionella litteraturstudier, konceptuell forskning med logiska resonemang och fallstudier i tillverkande företag. Resultaten visar att arbetet med att hantera negativa effekter av variationer är en komplex utmaning som stäcker sig bortom valet av att reducera eller absorbera variationerna. Generellt dras slutsatsen att det är flertalet aspekter att beakta för variationsadministration och buffertadministration med implikationer för kapacitetsadministrationen. Det visade sig att besluten tenderar att vara baserat på intuition och erfarenheter i tillverkande företag, mycket till följd av en avsaknad av beslutsstöd. Vidare framgår det att de medverkande företagen upplever att flera av deras interna rutiner bidrar till upphovet av variationer. Denna forskning bidrar till en ökad medvetenhet om orsaker till variationer som är påverkbara inom företag, möjliga åtgärder för att reducera variationerna och syftet med olika buffertar för att absorbera variationer. Detta är avsett att underlätta ett systematiskt arbetssätt för att reducera och absorbera variationer, samt utgöra ett stöd för variationsadministration och buffertadministration från ett kapacitetsadministrationsperspektiv. / KOPability

Submitted by Patrícia Valim Labres de Freitas (patricial) on 2016-04-01T17:52:53Z No. of bitstreams: 1 Thiago Antonio Souza.pdf: 1549573 bytes, checksum: 50bb2fe3750913e23e67747ffad33743 (MD5) / Made available in DSpace on 2016-04-01T17:52:53Z (GMT). No. of bitstreams: 1 Thiago Antonio Souza.pdf: 1549573 bytes, checksum: 50bb2fe3750913e23e67747ffad33743 (MD5) Previous issue date: 2015-12-23 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / CNPQ – Conselho Nacional de Desenvolvimento Científico e Tecnológico / Hospitais brasileiros tipicamente convivem com um desnivelamento entre capacidade e demanda. Os subsistemas público e privado são incapazes de coordenar situações de falta e excesso de capacidade identificados, de forma concomitante, em suas respectivas estruturas. Custos tornam-se um elemento focal em ambos os casos, quer visando qualidade e segurança quer visando incremento de capacidade, enfocando áreas chave do serviço hospitalar: serviços cirúrgicos, de internação, de emergência e de diagnóstico. O Lean Healthcare, neste contexto, se torna uma filosofia possível para a mudança organizacional dos processos hospitalares visando o incremento de sua eficiência. Este estudo discute a aplicação de conceitos do Lean Healthcare em serviços cirúrgicos, com base em evidências coletadas de três estudos realizados integradamente em um hospital universitário de grande porte, pertencente ao subsistema de saúde público brasileiro. O primeiro estudo enfoca a análise de eficiência do centro cirúrgico, propondo e aplicando o indicador Operating Room Effectiveness (ORE). O segundo, analisa e propõe formas de nivelar a produção (Heijunka) de cirurgias de diferentes demandas competindo pelo mesmo centro cirúrgico, em um contexto de capacidade inferior à demanda. O terceiro estudo desenvolve o conceito de Planejamento, Programação e Controle do Fluxo de Pacientes (PPCFP), com vistas ao planejamento integrado de consultas, cirurgias, pré-operatórios e aquisição de materiais. A aplicação dos modelos conceituais propostos revela potenciais vantagens, ainda a serem estudadas em amplitude e longitude como alternativa para outras organizações do setor. Como resultados locais, além do aporte de conceitos de Engenharia de Produção aplicada ao contexto de saúde, foram identificados: ganho operacional médio de 12% de eficiência nas salas de cirurgia; redução em 40% do tempo médio de espera para cirurgias eletivas; redução média de filas para consultas em 50%; melhor planejamento e controle de eficiência e produção; e economia de cerca de R$ 5.000.000,00 resultante dos três casos. / Brazilian hospitals typically work with a depression between capacity and demand. The public and private subsystems are unable to coordinate situations of shortage and excess capacity identified in their respective structures, concomitantly. Costs become a focal element in both cases, aiming to quality and safety or to increase capacity, focusing on key areas of hospital service: surgical services, admission, emergency and diagnostic. In this context, Lean Healthcare becomes an attractive philosophy for organizational change of hospital processes aiming at increasing its efficiency. This study discusses the application of Lean Healthcare concepts in surgical services, based on evidence collected from three studies integrally in a large University Hospital, part of the Brazilian public health subsystem. The first study focuses on the operating room efficiency analysis, proposing and applying the indicator Operating Room Effectiveness (ORE). The second study analyzes and proposes alternatives to level the production of surgeries (Heijunka) of different brands, competing for the same operating room, at a low capacity context. The third study develops the concept of Planning, Programming and Control of Patient Flow (PPCPF), to establish integrated planning consultations, surgeries, preoperative and acquisition of materials. The application of the proposed conceptual models reveals potential advantages, yet to be studied in amplitude and longitude as an alternative to other industry organizations. As local gains, in addition to the approximation of Industrial Engineering concepts to the health context, it have been identified: 12% increase in the surgical center’s average efficiency; 40% reduction in the average waiting time for elective surgery; 50% reduction in the number of queued consultations; better planning and control efficiency and production; and savings of about R$ 5,000,000.00 resulting from the three cases.

O setor industrial produtor de papel e celulose tem aumentado sua relevância comercial nas últimas décadas devido à demanda constantemente crescente. O aumento na competitividade do setor gerado pela economia globalizada e a dificuldade de desenvolvimento de bons planos de produção em ambientes produtivos cada vez mais complexos têm motivado a pesquisa por novas e efetivas ferramentas de auxílio à tomada de decisão. Considerando estas dificuldades, abordamos neste trabalho o problema de dimensionamento e sequenciamento de lotes com foco em empresas com processo integrado de produção de celulose e de papel. Trata-se de um problema de planejamento de médio a curto prazo, geralmente com maior enfoque no curto prazo por considerar o planejamento detalhado da produção em horizontes de planejamento que não superam 30 dias. No processo integrado de celulose e papel, foram consideradas as decisões de produção do digestor, evaporador, caldeira de recuperação e de múltiplas máquinas produtoras de papel, além do controle de estoque de produtos intermediários e finais. Modelos matemáticos da literatura foram modificados e estendidos para incorporar características adicionais do problema como, por exemplo, processos com múltiplas máquinas de papel. Além disso, foram desenvolvidas heurísticas construtivas, heurísticas de melhoria, abordagens de solução híbridas baseadas em algoritmos genéticos combinadas com ferramentas comerciais de solução exata, além de combinações entre os métodos. As abordagens desenvolvidas foram testadas computacionalmente e as melhores combinações de métodos foram definidas. De forma geral, os resultados dessas abordagens foram superiores aos obtidos por ferramentas de solução comerciais puras. Ademais, a variação proposta da heurística de melhoria fixe-e-otimize com mudanças na função objetivo se destacou com relação aos demais métodos, obtendo os melhores resultados, independentemente da qualidade da solução inicial utilizada. As principais contribuições desta tese são a apresentação de modelos matemáticos para representar apropriadamente o problema estudado, e o desenvolvimento de métodos de solução efetivos para resolver o problema. / The pulp and paper industry has been increasing the commercial importance in recent decades due to the constant growing demand. The increasing competitiveness of this sector generated by the globalized economy and the difficulty to develop good production plans in complex production environments have motivated the search for new and effective decision support systems. Given these difficulties, in this thesis we address the lot sizing and scheduling problem focused on integrated pulp and paper mills. This is a problem of medium to short term planning, generally more focused on the short term as it covers detailed production schedules in planning horizons which do not exceed 30 days. In these integrated pulp and paper process the production decisions of digester, evaporator, recovery boiler and multiple paper machines are considered, apart from the inventory control of intermediate and final products. Mathematical models known in the literature were modified and extended to incorporate additional features of the problem, such as processes with multiple paper machines. In addition, constructive and improvement heuristics, and hybrid methods based on genetic algorithms combined with a commercial solver were developed, as well as combinations of these solution approaches. The methods developed were computationally tested and the best combinations of methods were defined. Overall, the results of these methods were superior to the solutions obtained by pure commercial solvers. Moreover, the alternative variation proposed of the improvement heuristic fix-and-optimize with exchanges in the objective function surpassed the other methods, obtaining the best results, regardless of the quality of the initial solution used. The main contribution of this thesis are the presentation of mathematical models that appropriately represents the problem under study, and the development of effective solution methods to deal with the problem.

Thesis (Master of Military Studies)-Marine Corps Command and Staff College, 2008. / Title from title page of PDF document (viewed on: Feb 11, 2010). Includes bibliographical references.

Submitted by Victor Mario Noble Ramos (vicmanr90@gmail.com) on 2017-12-01T18:27:41Z No. of bitstreams: 2 TextoFinalDissertationVicman-PosDefesa.pdf: 37720288 bytes, checksum: e8e3336733bc8151bd42eab9118f2b2a (MD5) CartaTextoFinal.pdf: 241030 bytes, checksum: 8c46be374e02fb08ecd2b0f6ac30a27b (MD5) / Approved for entry into archive by Milena Rubi ( ri.bso@ufscar.br) on 2017-12-04T12:40:00Z (GMT) No. of bitstreams: 2 TextoFinalDissertationVicman-PosDefesa.pdf: 37720288 bytes, checksum: e8e3336733bc8151bd42eab9118f2b2a (MD5) CartaTextoFinal.pdf: 241030 bytes, checksum: 8c46be374e02fb08ecd2b0f6ac30a27b (MD5) / Approved for entry into archive by Milena Rubi ( ri.bso@ufscar.br) on 2017-12-04T12:40:12Z (GMT) No. of bitstreams: 2 TextoFinalDissertationVicman-PosDefesa.pdf: 37720288 bytes, checksum: e8e3336733bc8151bd42eab9118f2b2a (MD5) CartaTextoFinal.pdf: 241030 bytes, checksum: 8c46be374e02fb08ecd2b0f6ac30a27b (MD5) / Made available in DSpace on 2017-12-04T12:40:54Z (GMT). No. of bitstreams: 2 TextoFinalDissertationVicman-PosDefesa.pdf: 37720288 bytes, checksum: e8e3336733bc8151bd42eab9118f2b2a (MD5) CartaTextoFinal.pdf: 241030 bytes, checksum: 8c46be374e02fb08ecd2b0f6ac30a27b (MD5) Previous issue date: 2017-11-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / This dissertation adresses the general integrated lot sizing and scheduling problem for non-alcoholic beverage production with synchronization between stages and operating time windows for scheduling preventive maintenances. The problem is characterized by having two interdependent synchronized stages. In the first stage, machines (tanks) can supply several filling lines at the same time in the second stage, where the final items are packed. Production sequence-dependent times and costs exist. The review of the related literature indicates that existing models refer, generally, to particular cases of the general problem adressed here, the most common cases are the dedication of tanks to the lines, and disregarding the perishability of syrups and the possibility of scheduling preventive maintenances. A mathematical model for the general problem, called SMMRPM, has been proposed and applied in several instances to show the adherence and flexibility of the model to represent practical cases that can be found in reality. For the case of the dedication of tanks to lines, the model was compared with the dedicated model F1 (FERREIRA et al, 2012). The results indicate that the SMMRPM model is flexible and adherent to represent practical scenarios in which other models are not applicable, for example the possibility of scheduling preventive maintenance and consideration of perishability are differential of the proposal. In the plans obtained, it was shown that it is important to include these considerations that significantly affect the productive plans. In the case of dedication, compared to the dedicated model, the formulation SMMRPM achieves production plans, on average, 52.63 \% less costly than F1. / Nesta dissertação de mestrado é pesquisado o problema geral integrado de dimensionamento e sequenciamento de lotes da produção de bebidas não alcoólicas com sincronia ente os estágios e janelas de tempo de operação para programação de manutenções preventivas. O problema é caracterizado por ter dois estágios sincronizados e dependentes entre si. As máquinas do primeiro estágio (tanques) podem suprir ao mesmo tempo várias linhas de envase no segundo estágio, onde são envasados os itens finais. Existem tempos e custos de setup dependentes da sequência de produção. A revisão da literatura relacionada indica que modelos existentes referem-se, em geral, a casos particulares do problema geral aqui tratado, sendo que os casos mais comuns são a dedicação de tanques à linhas, e desconsideração da perecibilidade dos xaropes e da possibilidade de programar manutenções preventivas. Foi proposto um modelo matemático para o problema geral, denominado SMMRPM, e aplicado em diversas instâncias a fim de mostrar a aderência e a flexibilidade do modelo para representar casos práticos que podem ser achados na realidade. Para o caso da dedicação de tanques a linhas, o modelo foi comparado com o modelo dedicado F1 (FERREIRA et al, 2012). Os resultados indicam que o modelo SMMRPM é flexível e aderente para representar cenários práticos em que outros modelos não são aplicáveis, por exemplo a possibilidade de programar manutenções preventivas e consideração da perecibilidade são diferenciais da proposta. Nos planos obtidos foi mostrada a importância da inclusão destas considerações que afetam significativamente os planos produtivos. No caso da dedicação, comparado com o modelo dedicado, a formulação SMMRPM consegue planos de produção, em média, 52.63 % menos custosos que o F1. / Demanda Social

O setor industrial produtor de papel e celulose tem aumentado sua relevância comercial nas últimas décadas devido à demanda constantemente crescente. O aumento na competitividade do setor gerado pela economia globalizada e a dificuldade de desenvolvimento de bons planos de produção em ambientes produtivos cada vez mais complexos têm motivado a pesquisa por novas e efetivas ferramentas de auxílio à tomada de decisão. Considerando estas dificuldades, abordamos neste trabalho o problema de dimensionamento e sequenciamento de lotes com foco em empresas com processo integrado de produção de celulose e de papel. Trata-se de um problema de planejamento de médio a curto prazo, geralmente com maior enfoque no curto prazo por considerar o planejamento detalhado da produção em horizontes de planejamento que não superam 30 dias. No processo integrado de celulose e papel, foram consideradas as decisões de produção do digestor, evaporador, caldeira de recuperação e de múltiplas máquinas produtoras de papel, além do controle de estoque de produtos intermediários e finais. Modelos matemáticos da literatura foram modificados e estendidos para incorporar características adicionais do problema como, por exemplo, processos com múltiplas máquinas de papel. Além disso, foram desenvolvidas heurísticas construtivas, heurísticas de melhoria, abordagens de solução híbridas baseadas em algoritmos genéticos combinadas com ferramentas comerciais de solução exata, além de combinações entre os métodos. As abordagens desenvolvidas foram testadas computacionalmente e as melhores combinações de métodos foram definidas. De forma geral, os resultados dessas abordagens foram superiores aos obtidos por ferramentas de solução comerciais puras. Ademais, a variação proposta da heurística de melhoria fixe-e-otimize com mudanças na função objetivo se destacou com relação aos demais métodos, obtendo os melhores resultados, independentemente da qualidade da solução inicial utilizada. As principais contribuições desta tese são a apresentação de modelos matemáticos para representar apropriadamente o problema estudado, e o desenvolvimento de métodos de solução efetivos para resolver o problema. / The pulp and paper industry has been increasing the commercial importance in recent decades due to the constant growing demand. The increasing competitiveness of this sector generated by the globalized economy and the difficulty to develop good production plans in complex production environments have motivated the search for new and effective decision support systems. Given these difficulties, in this thesis we address the lot sizing and scheduling problem focused on integrated pulp and paper mills. This is a problem of medium to short term planning, generally more focused on the short term as it covers detailed production schedules in planning horizons which do not exceed 30 days. In these integrated pulp and paper process the production decisions of digester, evaporator, recovery boiler and multiple paper machines are considered, apart from the inventory control of intermediate and final products. Mathematical models known in the literature were modified and extended to incorporate additional features of the problem, such as processes with multiple paper machines. In addition, constructive and improvement heuristics, and hybrid methods based on genetic algorithms combined with a commercial solver were developed, as well as combinations of these solution approaches. The methods developed were computationally tested and the best combinations of methods were defined. Overall, the results of these methods were superior to the solutions obtained by pure commercial solvers. Moreover, the alternative variation proposed of the improvement heuristic fix-and-optimize with exchanges in the objective function surpassed the other methods, obtaining the best results, regardless of the quality of the initial solution used. The main contribution of this thesis are the presentation of mathematical models that appropriately represents the problem under study, and the development of effective solution methods to deal with the problem.

Master's thesis is aimed to analysis, change proposition and benefit assessment in real company called by fictional name Stavební výroba a.s. In my thesis I'll focus on functionality of current information system so it can satisfy needs of management and also has finacial benefits over old system.

The diploma thesis Order optimization and validation of resource capacities in company Formex s.r.o. is composed from three parts. The first one is an introduction to the types and specifications of production systems. It also follows production planning and control. The second part is dedicated to analysis of the information system WorkPlan and to the analysis of the company Formex s.r.o. (the company structure, the production and the planning process). The possible ways of production planning and order optimization with respect to the use of IS WorkPlan were designed in the third part of the diploma thesis. Consequently the most suitable planning way was selected and the templates with the normalized technological processes were designed. The diploma thesis also contains validation of the proposals and it is enclosed with the recommendation for the future steps in the production planning in the company Formex s.r.o.

El presente proyecto de investigación se enfoca en la mejora del proceso del planeamiento y control de operaciones basada en la aplicación de los conceptos de la gestión por procesos para la mejora de los resultados en las mypes arandaneras ubicadas en la provincia de Cañete, Perú. Generalmente, las pequeñas empresas no cuentan con un sistema estándar en sus procesos, generando deficiencias en sus operaciones a lo largo de su campaña productiva. Según el análisis realizado, estas deficiencias se ven reflejadas en la rentabilidad del negocio, con una pérdida del margen de 7.47% o $323 565; por ello, se propone un modelo estándar de planeamiento y control de operaciones para ayudar a las pequeñas empresas a estructurar, alinear e integrar cada entregable de los subprocesos como los planes, programas y controles necesarios en las operaciones del cultivo de arándanos. / This research project focuses on the improvement of Operations planning and control process based on the application of the concepts of process management concepts to improve the results in the blueberry companies located in Cañete, Peru. Generally, small companies do not have a standard model in their processes, generating deficiencies in their operations throughout their production campaign. According to the analysis carried out, these deficiencies are reflected in the business profitability, with a margin loss of 7.47% or $ 323,565; therefore, a standard model of planning and control of operations is proposed to help small companies to structure, align and integrate each deliverable of the sub-processes such as the plans, programs and controls necessary in the operations of the blueberry cultivation. / Tesis