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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Examining a comparative depiction of crime in Smith and Nesbo's selected novels : an afro-western perspective

Malatji, Permission Agosi January 2019 (has links)
Thesis (M. A.(English Studies)) --University of Limpopo, 2019 / This study explores a literary comparative examination of crime between Africa and Scandinavia, with special attention to Botswana and Norway. Smith’s and Nesbo’s selected novels are used as primary texts for analysis. The novels are, therefore, set in two different areas. These writers depict crime from the African and European perspectives. Chapter One deals with a brief introduction, and the aim and objectives of the study. It also expands on the theoretical background and provides definitions of terms that are used in this paper. Chapter Two presents views from various scholars on crime. This study is based on an Afro-Western approach of literary analysis. In other words, there are thoughts by both African and Western writers which assist in determining possible and noticeable similarities and differences, on the issue of crime. Chapter Three analyses crime from an African perspective while Chapter Four discusses crime from a Western point of view. Each of these chapters reflects on crime through character portrayal and depiction within its context. Chapter Five is a comparative analysis of both novels. The chapter identifies possible similarities and differences, mainly of the depiction of crime in different settings – Africa and Scandinavia, committed by blacks and whites. However, the structural and linguistic approaches of both the novels are also reviewed, assisting in discovering the life, in comparison, of the authors. The last chapter (Chapter Six), is a conclusion of the study and future suggestions. Basically, the study argues that blacks only should not be portrayed as perpetrators, but that whites too can be culprits. Again, there should be an equal of measurement on the weight and honour of the two races. Lastly, the moral is that without considering skin colour, financial and social backgrounds, justice must be served equally. Hence, whoever is caught in any form of wrongdoing, they must be given the appropriate punishment – regardless of race, colour, religious creed, gender, financial and social background. Key Words: Crime, Afro-Western, Marxism, suspense, detective, identity, puzzle, fix, accumulation, class, characterisation and setting
42

The Political Economy of Retailing Sustainable Food: Green Consumerism and Sustainability

Toofan, Megan H. 12 1900 (has links)
In recent decades, the global impacts of unsustainable consumption and production patterns have become a leading topic of sustainability, and more recently, climate action discourse. At the policy level, green consumerism – an element of green capitalism – has been positioned as the pathway to more sustainable consumption and production (SCP) practices. Within this model, eco-labeling schemes are used to communicate various sustainability attributes, or conditions of production, to the consumer. This study set out to investigate whether SCP is achievable through green consumerism using a two-part case study that centers around the egg industry and specific hen welfare standards. The case study examines the effectiveness of egg eco-labeling schemes and related statements and images placed on egg packaging in informing consumers' purchasing decisions. It also examines the impacts of green consumerism on organic egg production in the presence of strong consumer demand for enhanced hen welfare standards. The results of the case study demonstrate that in the egg industry, green consumerism is not highly effective because consumers' purchasing decisions are often informed by vague and misleading information about conditions of production. Moreover, the presence of strong consumer demand has not resulted in enhanced hen welfare standards in organic production. In interpreting these findings through the lens of David Harvey's theory of the spatial fix, I argue that the true role of green consumerism is to facilitate a spatial fix to resolve the chronic crisis of overaccumulation in the conventional egg industry. Furthermore, that the limitations and contradictions within green consumerism (e.g. vague or insignificant eco-label claims) aid in removing the barrier of capital fixity so that the spatial fix can occur.
43

Dimensionamento e sequenciamento de lotes de produção na indústria de bens de consumo de higiene pessoal. / Lot sizing and sequencing in the personal hygiene consumer goods industry.

Kawamura, Márcio Seiti 11 November 2011 (has links)
O presente trabalho trata do problema integrado de dimensionamento e sequenciamento de lotes de produção. O processo de dimensionar e sequenciar lotes de produção consiste em determinar quanto produzir de cada produto e a sequência de produção desses lotes em cada máquina a cada período a fim de atender a uma demanda prevista sob as condições e capacidades operacionais existentes. O caso estudado nesse trabalho aborda o cenário de uma empresa de grande porte da indústria de bens de consumo de higiene pessoal, um mercado bastante concorrido no qual o bom nível de serviço de atendimento e a gestão de custos mostram-se essenciais na competição pelos clientes. Nessa empresa, existe um ambiente operacional complexo, composto por máquinas distintas em paralelo com capacidade limitada de produção cujos tempos de preparação (setup) são dependentes da sequência de produção, além de uma restrição de capacidade de armazenagem dos produtos fabricados, característica não encontrada na literatura existente. Os clientes permitem que ocorram atrasos de atendimento da demanda, porém isso é extremamente indesejável. Esse tipo de problema é NP-difícil, sendo geralmente tratado na literatura por heurísticas. Nesse trabalho, elaboramos nove diferentes estratégias de resolução baseadas na heurística relax-and-fix. O objetivo é, não somente resolver um problema real complexo, como também avaliar se o modo de articionamento e a sequência de resolução dos subproblemas influencia no desempenho da heurística. Os testes computacionais foram conduzidos em instâncias geradas aleatoriamente e em casos reais. Os resultados mostraram um bom desempenho e robustez da abordagem proposta. Técnicas alternativas foram aplicadas na estratégia com os melhores resultados para potencializar seu desempenho. / This work adresses the integrated lot sizing and scheduling problem. The process of lot sizing and scheduling consists of determining how much to produce of each product and the scheduling of these lots in each machine in order to meet the demand under existing restrictions and operational capabilities. The case studied in this work describes the scenario of a big company in the industry of consumer goods for personal hygiene, a very competitive market in which the good service level for customers and the cost management show up in the competition for the clients. In this company, there is a complex operational environment, composed of distinct parallel machines with limited production capacity and sequence dependente setup times. There is also a limited finished goods storage capacity, a characteristic not found in the existing literature. Backordering is allowed but it is extremely undesirable. This problem is NP-hard and it has been treated by heuristics in the literature. In this work, we developed nine different solving strategies based on the relax-and-fix heuristics. The aim of this approach is not only to solve a complex real problem but also assess whether the form of partitioning and the sequence of solving the subproblems influences the performance of the relax-and-fix heuristics. The computational experiments were conducted on ramdomly generated instances and real problems. The results showed the good performance and the robustness of the proposed approach. Alternative techniques were applied in the strategy with the best results in the previous tests to enhance its performance.
44

Problema integrado de dimensionamento de lotes e corte de estoque: modelagem matemática e métodos de solução / A general integrated lot-sizing and cutting stock problem: mathematical modelling and solution methods

Melega, Gislaine Mara [UNESP] 21 February 2017 (has links)
Submitted by GISLAINE MARA MELEGA null (gis_laine_m@hotmail.com) on 2017-03-27T18:20:11Z No. of bitstreams: 1 TESE_Gislaine Melega_Matemática.pdf: 2710288 bytes, checksum: 9c3a4e388e7584cf0423182dcfdcced8 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-03-29T19:23:05Z (GMT) No. of bitstreams: 1 melega_gm_dr_sjrp.pdf: 2710288 bytes, checksum: 9c3a4e388e7584cf0423182dcfdcced8 (MD5) / Made available in DSpace on 2017-03-29T19:23:05Z (GMT). No. of bitstreams: 1 melega_gm_dr_sjrp.pdf: 2710288 bytes, checksum: 9c3a4e388e7584cf0423182dcfdcced8 (MD5) Previous issue date: 2017-02-21 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Nesta tese, estamos interessados em tratar de maneira integrada dois conhecidos problemas da literatura. Esta integração é referida na literatura como problema integrado de dimensionamento de lotes e corte de estoque. A ideia consiste em considerar simultaneamente, as decisões relacionadas com ambos os problemas, de modo a capturar a interdependência entre estas decisões e, assim, obter uma melhor solução global. Propõe-se um modelo matemático geral para o problema integrado de dimensionamento de lotes e corte de estoque (GILSCS), que considera vários níveis de integração e nos permite classificar a literatura, em termos de modelos matemáticos, dos problemas integrados. A classificação é organizada a partir de dois principais aspectos de integração que são: a integração através dos períodos de tempo e a integração entre os níveis de produção. Em um horizonte de planejamento que considera vários períodos, o estoque fornece uma ligação entre os períodos. Esta integração, por períodos de tempo, constitui o primeiro tipo de integração. O problema geral também considera a produção em diferentes níveis: objetos são fabricados ou comprados e então são cortados para produzir peças menores e estas, por sua vez, constituem componentes para a produção dos produtos finais. A integração entre os diferentes níveis de produção consiste no segundo tipo de integração. A revisão da literatura também possibilita direcionar interessantes áreas para pesquisas futuras. O comportamento da solução para este tipo de problema, com três níveis e vários períodos, é estudado a partir do desenvolvimento de métodos de solução considerando abordagens que superam as dificuldades do problema, que consistem no alto número de padrões de corte, estruturas em vários níveis (multiestágios) e variáveis binárias de preparo. Os métodos de solução propostos para o problema GILSCS são baseados em duas abordagens conhecidas da literatura, usadas com sucesso para resolver os problemas separadamente, que são o procedimento de geração de colunas e heurísticas de decomposição do tipo relax-and-fix. Estas estratégias e suas variações são combinadas à um pacote de otimização em um estudo computacional com dados gerados aleatoriamente. Uma revisão da literatura, em termos de métodos de solução, para o problema integrado também é apresentada. Outras contribuições desta tese consistem em propor diferentes modelos matemáticos para o problema integrado, combinando modelos alternativos para cada um dos problemas separadamente. Neste estudo, o objetivo é comparar e avaliar, com um extensivo estudo computacional, a qualidade e o impacto das diferentes formulações. O outro trabalho trata de uma aplicação do problema integrado em um indústria de móveis de pequeno porte, em que restrições específicas do ambiente industrial são abordadas, como estoque de segurança e ciclos da serra. A solução obtida pelo modelo proposto é comparada com uma simulação da prática da empresa. / In this thesis, the subject of interest is in treating, in an integrated way, two wellknown problems in the literature. This integration is referred in the literature as the integrated lot-sizing and cutting stock problem. The basic idea is to consider, simultaneously, the decisions related to both problems so as to capture the interdependency between these decisions in order to obtain a better global solution. We propose a mathematical model for a general integrated lot-sizing and cutting stock (GILSCS) problem. This model considers multiple dimensions of integration and enables us to classify the current literature, in terms of mathematical models, in this field. The main classification of the literature is organized around two types of integration. In a planning horizon which consists of multiple periods, the inventory provides a link between the periods. This integration across time periods constitutes the first type of integration. The general problem also considers the production in different levels: objects are fabricated or purchased and then, they are cut to produce the pieces which are then assembled as components in the production of final products. The integration between these production levels constitutes the second type of integration. The literature review also enables us to point out interesting areas for future research. The behavior of a solution to this type of problem, with three levels of production and several time periods, is studied considering the development of solution approaches that overcome the difficulties of the problem, which are the high number of cutting patterns, multi-level structures and the binary values of the setup variables. The solution methods proposed to the GILSCS problem are based on two known strategies from the literature which are used successfully to solve the problems separately, which are the column generation procedure and decomposition heuristics based on relax-and-fix procedure. These strategies and their variations are combined into an optimization package in a computational study with randomly generated data. A literature review, in terms of solution methods, to the integrated problem, is also presented. Other contributions of this thesis consist of proposing different mathematical models for the integrated problem combining alternative models for each one of the problems separately. In this study, the aim is to compare and evaluate, with an extensive computational study, the quality and the impact of these dfifferent formulations. Another study is an application of the integrated problem in a small furniture factory, in which specific constraints related to the industrial environment are addressed, such as, safety stock level constraints and saw cycles constraints. The solution obtained from the proposed model is compared to a simulation of the common practice in the company. / FAPESP: 2012/20631-2
45

Programação das frentes de colheita de cana-de-açúcar: uma modelagem visando o equilíbrio das capacidades de colheita e transporte

Junqueira, Rogério de Ávila Ribeiro 09 June 2014 (has links)
Made available in DSpace on 2016-06-02T19:50:25Z (GMT). No. of bitstreams: 1 6346.pdf: 5901404 bytes, checksum: 2d78b0f5f68ac25a089acd315f55b157 (MD5) Previous issue date: 2014-06-09 / The production of sugar, ethanol and electricity from sugar cane necessarily involves harvesting and transportation of raw materials, which are expensive and complex operations and have significant influence on the quality of the industrial raw material. The literature reports several optimization approaches related to the planning of planting, harvesting and transporting of sugarcane, however the scheduling of harvesting fronts is underexplored. This thesis intends to contribute to the state-of-art of this important issue in the context of the Brazilian agribusiness. Optimization approaches to support scheduling decisions of harvesting fronts considering the balance of harvesting and transportation capacities, as well as good agronomic management are proposed. The approaches are inspired by the representation of the problem as a lot sizing and scheduling model with parallel machines and sequence-dependent setup costs and times, a modelling technique well studied in the production planning and control literature. Three variants of this formulation, based on mathematical programming models, were developed and tested in two real case studies of medium size sugar mills. Heuristic methods based on aggregation procedures and mathematical programming have also been studied and developed to solve large scaled problems found in practice. Among the three variants studied, one presented the best solution quality within the expected execution time. Important scenario analysis were done indicating that the schedule s fulfilment provides reduction of harvesting and transporting complexity to the following season, which can generate significant saves in the cases studied. Besides that, comparing the proposed scheduling method with one of the sector s practice, it can be generated also significant cost reduction in the cases studied. The results were analyzed according to a validation methodology (descriptive facet of tetraedrum) well known in the literature. / A produção de açúcar, álcool e energia elétrica a partir de cana-de-açúcar passa necessariamente pela colheita e transporte da matéria-prima, que são operações custosas, complexas e que interferem significativamente na qualidade da matéria-prima industrial. A literatura reporta várias abordagens de otimização relacionadas ao planejamento do plantio, da colheita e do transporte de cana-de-açúcar, todavia a programação das frentes de colheita é pouco explorada. Nesta tese pretende-se contribuir para o estado da arte deste importante tema no contexto do agronegócio brasileiro. Propõe-se abordagens de otimização para apoiar decisões de programação das frentes de colheita, considerando-se o equilíbrio das capacidades de colheita e transporte, bem como um bom manejo agronômico. As abordagens são inspiradas na representação do problema por meio de um modelo de dimensionamento de lotes e sequenciamento da produção em máquinas paralelas com custos e tempos de setup dependentes da sequência, bem estudado na literatura em contextos de planejamento e controle da produção. Para isso foram desenvolvidas três variantes desta formulação baseadas em programação matemática, voltadas para a programação das frentes de colheita, que foram testadas em dois estudos de caso reais de usinas de cana-de-açúcar de médio porte do setor. Métodos heurísticos baseados em procedimentos de agregação e programação matemática também foram estudados e desenvolvidos para a resolução dos problemas de grande porte encontrados na prática. Das três variantes estudadas, uma delas apresentou melhor qualidade da solução dentro de tempos computacionais aceitáveis para o problema. Análises de cenário importantes foram feitas indicando que o cumprimento da programação proporciona redução de complexidade da colheita e transporte na safra seguinte, podendo gerar economias significativas nos casos estudados. Além disso, a comparação dos resultados das abordagens aqui exploradas com o que é praticado no setor indica um potencial de redução de custos também significativo para os casos estudados. Os resultados foram analisados de acordo com uma metodologia de validação (faceta descritiva do tetraedro) conhecida na literatura.
46

Dimensionamento e sequenciamento de lotes de produção na indústria de bens de consumo de higiene pessoal. / Lot sizing and sequencing in the personal hygiene consumer goods industry.

Márcio Seiti Kawamura 11 November 2011 (has links)
O presente trabalho trata do problema integrado de dimensionamento e sequenciamento de lotes de produção. O processo de dimensionar e sequenciar lotes de produção consiste em determinar quanto produzir de cada produto e a sequência de produção desses lotes em cada máquina a cada período a fim de atender a uma demanda prevista sob as condições e capacidades operacionais existentes. O caso estudado nesse trabalho aborda o cenário de uma empresa de grande porte da indústria de bens de consumo de higiene pessoal, um mercado bastante concorrido no qual o bom nível de serviço de atendimento e a gestão de custos mostram-se essenciais na competição pelos clientes. Nessa empresa, existe um ambiente operacional complexo, composto por máquinas distintas em paralelo com capacidade limitada de produção cujos tempos de preparação (setup) são dependentes da sequência de produção, além de uma restrição de capacidade de armazenagem dos produtos fabricados, característica não encontrada na literatura existente. Os clientes permitem que ocorram atrasos de atendimento da demanda, porém isso é extremamente indesejável. Esse tipo de problema é NP-difícil, sendo geralmente tratado na literatura por heurísticas. Nesse trabalho, elaboramos nove diferentes estratégias de resolução baseadas na heurística relax-and-fix. O objetivo é, não somente resolver um problema real complexo, como também avaliar se o modo de articionamento e a sequência de resolução dos subproblemas influencia no desempenho da heurística. Os testes computacionais foram conduzidos em instâncias geradas aleatoriamente e em casos reais. Os resultados mostraram um bom desempenho e robustez da abordagem proposta. Técnicas alternativas foram aplicadas na estratégia com os melhores resultados para potencializar seu desempenho. / This work adresses the integrated lot sizing and scheduling problem. The process of lot sizing and scheduling consists of determining how much to produce of each product and the scheduling of these lots in each machine in order to meet the demand under existing restrictions and operational capabilities. The case studied in this work describes the scenario of a big company in the industry of consumer goods for personal hygiene, a very competitive market in which the good service level for customers and the cost management show up in the competition for the clients. In this company, there is a complex operational environment, composed of distinct parallel machines with limited production capacity and sequence dependente setup times. There is also a limited finished goods storage capacity, a characteristic not found in the existing literature. Backordering is allowed but it is extremely undesirable. This problem is NP-hard and it has been treated by heuristics in the literature. In this work, we developed nine different solving strategies based on the relax-and-fix heuristics. The aim of this approach is not only to solve a complex real problem but also assess whether the form of partitioning and the sequence of solving the subproblems influences the performance of the relax-and-fix heuristics. The computational experiments were conducted on ramdomly generated instances and real problems. The results showed the good performance and the robustness of the proposed approach. Alternative techniques were applied in the strategy with the best results in the previous tests to enhance its performance.
47

Fixed-point implementace rozpoznávače řeči / Fixed-Point Implementation Speech Recognizer

Král, Tomáš January 2007 (has links)
Master thesis is related to the problematics of automatic speech recognition on systems with restricted hardware resources - embedded systems. The object of this work was to design and implement speech recognition system on embedded systems, that do not contain floating-point processing units. First objective was to choose proper hardware architecture. Based on the knowledge of available HW resources, the recognition system design was made. During the system development, optimalization was made on constituent elements so they could be mounted on chosen HW. The result of the the project is successful recognition of Czech numerals on embedded system.
48

The Political Ecology of Green Hydrogen from the global South : An analysis along the socioecological fix framework / Den gröna vätgasens politiska ekologi sett från det globala syd

Rischer, Maximilian January 2023 (has links)
Infrastructural projects to realize the energy transition are framed by governmentsfrom all around the world very positively. This is also the case for green hydrogen,which is considered as a silver bullet to solve multiple crises simultaneously. ThisMaster thesis explores the drivers behind the ramp-up of the hydrogen economy inthe global South and elaborates on socio-economic and ecological implications ofgreen hydrogen production projects to analyse the truthfulness of the positivenarratives of the benefits of green hydrogen. To accomplish this, an internationalgreen hydrogen project led by the German-British company Hyphen and planned tobe established in Namibia, was used as an emblematic case study. Following the framework of the socioecological fix, the findings strongly indicatethat green hydrogen does not significantly contribute in solving the climate crisis andsocial problems. Contrarily, strongly influenced by domestic and internationalpolitics, the project in Namibia seems to primarily fix the crisis of capitalism, which isthe overaccumulation of capital that requires new ways of circulation to makecapitalism renew itself. By commodifying and integrating natural resources in globalvalue chains, the Namibian society is disadvantaged, and few actors, primarily fromabroad, profit. Similarly, the finance approach of the project pushes Namibia intopotential financial dependencies. Besides that, the legacy from German colonialismand South African occupation before liberation is manifested in where and how theinfrastructure of hydrogen production is envisioned and planned. There is a risk thatthe hegemonies of elite social classes sustain their position and that social inequalitiesmight be reinforced through a project heralded as benefitting the whole nation. By assessing the political ecology of green hydrogen, I contribute to a critical researchagenda, that considers global inequalities, colonial histories, and ideologies. This willhopefully help to build a foundation for a truly decolonial and just energy transition,all around the world. / Infrastrukturprojekt som bidrar till realiseringen av energiomställningen har fått enöverlag mycket positiv inramning av regeringar i världen. Detta gäller i synnerhetgrön vätgas vilket betraktas som en lösning till flertalet olika kriser. I denna master-uppsats undersöks drivkrafterna bakom den massiva ökningen av vätgas-ekonomin iden globala södern, samt de socioekonomiska och ekologiska konsekvenserna avprojekt som behandlar produktionen av grön vätgas. Vidare utvärderas huruvidaden positiva inramningen beskriver sanningen av dessa vätgasprojekt korrekt. Föratt uppnå detta användes ett grönt vätgasprojekt som leds av det tysk-brittiskakonsortiet Hyphen, och som planeras att etableras i Namibia, som en emblematiskfallstudie. Enligt ramverket socioekologisk fix som kommer från politisk ekologi,tyder resultaten starkt på att vätgas inte bidrar väsentligt till att lösa klimat-krisen ejheller sociala problem i den globala södern. Tvärtom, starkt påverkad av inhemskoch internationell politik, så verkar bidra till att lösa kapitalismens kristendens, vilketär överackumulering av kapital som kräver nya sätt för att cirkuleras så att kapital-ismen kan förnya sig själv. Genom att göra naturresurser till handelsvaror och integr-era dem i globala värdekedjor så riskerar det det namibiska samhället attmissgynnas, medan ett fåtal internationella aktörer tjänar på det. På samma sätt lederprojektets finansierings-strategi till att Namibia hamnar i ett potentiellt finansielltberoende. Dessutom syns arvet från tysk kolonialism och den sydafrikanskaapartheidregimens ockupation i och hur infrastrukturen för produktion av vätgasplaneras. På så sätt kan hegemoniska strukturer som vidmakthåller sociala eliter ochdärmed sociala ojämlikheter förstärkas genom ett projekt som sägs gynna helanationen. Genom att utvärdera den gröna vätgasens politiska ekologi bidrar jag tillen kritisk forskningsagenda som tar hänsyn till globala ojämlikheter, kolonialahistorier och olika ideologier. Detta kommer förhoppningsvis också att bidra till attrealisar en avkolonisering och rättvis energiomställning över hela världen.
49

A matheuristic approach for solving the high school timetabling problem / Uma abordagem matheurística para resolver o problema de geração de quadros de horários escolares do ensino médio

Dornelles, Arton Pereira January 2015 (has links)
A geração de quadros de horários escolares é um problema clássico de otimização que tem sido largamente estudado devido a sua importâncias prática e teórica. O problema consiste em alocar um conjunto de aulas entre professor-turma em períodos de tempo pré-determinados, satisfazendo diferentes tipos de requisitos. Devido a natureza combinatória do problema, a resolução de instâncias médias e grandes torna-se uma tarefa desafiadora. Quando recursos são escassos, mesmo uma solução factível pode ser difícil de ser encontrada. Várias técnicas tem sido propostas na literatura científica para resolver o problema de geração de quadros de horários escolares, no entanto, métodos robustos ainda não existem. Visto que o uso de métodos exatos, como por exemplo, técnicas de programação matemática, não podem ser utilizados na prática, para resolver instâncias grandes da realidade, meta-heurísticas e meta-heurísticas híbridas são usadas com frequência como abordagens de resolução. Nesta pequisa, são desenvolvidas técnicas que combinam programação matemática e heurísticas, denominadas mateheurísticas, para resolver de maneira eficiente e robusta algumas variações de problemas de geração de quadros de horários escolares. Embora neste trabalho sejam abordados problemas encontrados no contexto de instituições brasileiras, os métodos propostos também podem ser aplicados em problemas similares oriundo de outros países. / The school timetabling is a classic optimization problem that has been extensively studied due to its practical and theoretical importance. It consists in scheduling a set of class-teacher meetings in a prefixed period of time, satisfying requirements of different types. Given the combinatorial nature of this problem, solving medium and large instances of timetabling to optimality is a challenging task. When resources are tight, it is often difficult to find even a feasible solution. Several techniques have been developed in the scientific literature to tackle the high school timetabling problem, however, robust solvers do not exist yet. Since the use of exact methods, such as mathematical programming techniques, is considered impracticable to solve large real world instances, metaheuristics and hybrid metaheuristics are the most used solution approaches. In this research we develop techniques that combine mathematical programming and heuristics, so-called matheuristics, to solve efficiently and in a robust way some variants of the high school timetabling problem. Although we pay special attention to problems arising in Brazilian institutions, the proposed methods can also be applied to problems from different countries.
50

Modeling the fixed bed drying characteristics of biomass particles

Yang, Hai 21 June 2012 (has links)
The fixed bed drying of western hemlock and Douglas-fir biomass particles at temperatures ranging from 50��C to 200��C and air velocities from 0.3 to 0.9 m/s was investigated. The objectives were to describe the drying characteristics of the particles, fit a model for thin-layer drying, and develop and test a deep bed drying model based on the thin-layer model. The effects of temperature and air velocity were determined in a bed approximately 1.3 cm in depth and a model for the drying curve was developed. The thin-layer model was then used to predict what would happen in a deeper bed. Model results were compared to drying curves measured in a 23-cm-deep bed. The deep bed model predicted both the experimental drying times and the moisture and temperature profiles in the bed. / Graduation date: 2013

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