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A mathematical framework for designing and evaluating control strategies for water- & food-borne pathogens : a norovirus case studyMcMenemy, Paul January 2017 (has links)
Norovirus (NoV) is a significant cause of gastroenteritis globally, and the consumption of oysters is frequently linked to outbreaks. Depuration is the principle means employed to reduce levels of potentially harmful agents or toxins in shellfish. The aim of this thesis is to construct mathematical models which can describe the depuration dynamics of water-borne pathogens, and specifically examine the dynamics of NoV during depuration for a population shellfish. Legislation is currently under consideration within the EU by the Directorate-General for Health and Consumers (DG SANCO) to limit the maximum level of NoV that consumers are exposed to via this route. Therefore it is important to the utility of the thesis that any models constructed should incorporate control measures which could be used to implement minimum NoV levels. Doing so allowed calculation of minimum depuration times that would be required to adhere to the control measures incorporated into the models. In addition to modelling the impact on pathogens during the depuration, we wished to gain some insight into how the variability, and not just the mean levels, of water-borne pathogens can be as important with respect to the length of depuration required to minimise any food safety risks to the consumer. This proved difficult in the absence of any data sets that can be used to calculate variability measures, as little data is currently available to inform these values for NoV. However, our modelling techniques were able to calculate an upper limit on the variability of water-borne pathogens that can be well approximated by lognormal distributions. Finally we construct a model which provided linkage between the depuration process and the accretion of pathogens by shellfish while still within farming waters. This model proposed that the pulses of untreated waste waters released by sewage treatment works due to high levels of rainfall would be transmitted into shellfish whilst filter-feeding.
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Contribuição dos fatores internos e externos para o desempenho das empresas brasileiras e sua evolução na última décadaGonçalves, André Ribeiro January 2005 (has links)
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Previous issue date: 2005 / Este trabalho analisa a contribuição dos efeitos da estratégia da empresa, do setor
em que ela opera, do grupo econômico a que pertence e da conjuntura econômica
como um todo para a lucratividade das empresas brasileiras no período de 1996 a
2003. Também é verificada a evolução da contribuição destes fatores ao longo do
período. Finalmente o modelo é testado com outra variável dependente,
correspondendo às características da estrutura do capital das empresas. Os
resultados demonstram que o principal elemento da lucratividade é a estratégia da
empresa. A participação da estratégia vem aumentando nos últimos oito anos.
Contrariamente ao esperado, o efeito da conjuntura é muito pequeno e semelhante
ao encontrado no mercado americano. Também surpreende os resultados para a
estrutura de capital. Ao contrário do esperado, o modelo revela uma importância
ainda maior da estratégia, com uma pequena participação do mercado de atuação. / Salvador
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Optimisation de la gestion du service de maintenance biomédicale / Optimization of the biomedical maintenance service managementBen Houria, Zeineb 21 November 2016 (has links)
Le milieu hospitalier est un monde à la fois sensible et complexe, sensible parce que la vie humaine est en jeu et complexe parce que les équipements médicaux augmentent en nombre et en complexité technique. Ainsi, afin de préserver le bon état de fonctionnement de ces équipements et à un niveau élevé de disponibilité, leur entretien est devenu l'une des préoccupations majeures des responsables de l’hôpital. L’objectif de cette thèse est de proposer, aux responsables de maintenance biomédicale dans les établissements de soins, des outils d’aide à la décision qui permettent une meilleure maitrise des coûts. Ceci en assurant la sécurité des patients et des utilisateurs et en maintenant des performances optimales de l’ensemble des équipements médicaux. Tout d’abord, une heuristique a été proposée pour le choix de l’internalisation ou de l’externalisation de la maintenance et pour la sélection du contrat adéquat. La sélection du contrat est basée sur un ensemble de critères tout en considérant la contrainte du budget disponible. Ensuite, afin d’améliorer la procédure proposée, nous avons proposé des outils d’aide à la décision multicritère pour le choix adéquat d’une stratégie de maintenance. Pour l’étude de la criticité des équipements médicaux et le choix de la maintenance, sept critères ont été étudiés en proposant un couplage de l’approche AHP « Analytical Hierarchy Process » à la technique TOPSIS « Technique for Order Performance by Similarity to Ideal Solution ». Comme les experts du service de maintenance présentaient une certaine incertitude dans leurs jugements, nous avons intégré l’évaluation linguistique floue dans l’étude de la criticité des équipements et dans la sélection de la stratégie de maintenance (Fuzzy AHP couplée avec Fuzzy TOPSIS). Un modèle mathématique MILP a été développé pour la définition des limites de la criticité afin de caractériser les trois stratégies de maintenance. Le bon choix de ces limites permet d’optimiser le coût de la maintenance en respectant le budget disponible. Enfin, un deuxième modèle mathématique MILP a été développé en se basant sur l’heuristique proposée. Ce modèle permet de sélectionner pour chaque équipement, la stratégie de maintenance, internaliser ou externaliser la maintenance et le type du contrat tout en considérant le budget disponible et la charge/capacité du service maintenance / The hospital is a world that is both sensitive and complex, sensitive because the human life is involved and complex because medical facilities are growing in number and in technical complexity. Then, the problem of the medical equipment maintenance in order to keep them in safe, reliable and with high level of availability has become a major preoccupation of the hospital. The objective of this thesis is to provide tools to help the biomedical maintenance service of the hospital to make decisions that allow a better control of costs, while ensuring patient and user safety and maintaining optimal performance of medical equipment. First, a heuristic has been proposed for the choice of internalization or outsourcing maintenance and for the selection of the appropriate contract. The selection of the contract is based on a set of criteria while considering the available budget constraint. Then, to improve the proposed procedure, we proposed multi-criteria decision-making tools to select the appropriate maintenance strategies. Seven criteria have been designed to study the criticality of medical equipment and the choice of maintenance by providing a coupling of the AHP approach "Analytical Hierarchy Process" with TOPSIS technique "Technique for Order Performance by Similarity to Ideal Solution." As the expert judgments of the maintenance department presented some uncertainty, we integrated the fuzzy language assessment of the criticality of the equipment and the selection of the maintenance strategy (Fuzzy AHP coupled with Fuzzy TOPSIS). A mixed integer linear programming model (MILP) was developed to define thresholds of criticality to characterize the three maintenance strategies. According to these thresholds, maintenance cost can be optimized within the available budget. Finally, a second mixed integer linear programming model (MILP) was developed based on the proposed heuristic. This model allows selecting for each equipment, the maintenance strategy, the internalization or the outsourcing of the maintenance and the type of contract while considering the available budget and the workload / capacity of the maintenance department
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Produção de tomateiro cultivado com acrescent solus® / Yeld of tomato cultivated with acrescent solus®Schwertner, Diogo Vanderlei 15 February 2012 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objectives of this study were: verify the adequation to the presuppositions of the
mathematical model and, identify data transformation for productive and morphological
variables of tomato in experiments in plastic tunnel and in field, considering each harvest date
and grouped harvests during spring-summer and autumn-winter seasons; and, to evaluate the
effect of the application of Acrescent Solus® in complementation and/or substitution to the
mineral fertilization in coverage over productive and morphological variables, quality of fruit
and color of leaves of tomato cultivated in plastic tunnel and in field during springsummer
and autumn-winter seasons. Two experiments were conducted in plastic tunnel
(spring-summer and autumn-winter) and one in field (spring-summer), both in a randomized
block design with three replications in a bifactorial (2x4), with four additional controls. The
tests of: non-additivity of Tukey, Lilliefors, Bartlett and Run Test, were used, respectively, for
verify the adequation to the presuppositions of: additivity of the model, normality,
homogeneity and randomness of errors. In cases of violation, the data were transformed and,
submitted again to the analysis of the presuppositions of the mathematical model. The
productive and morphological variables of tomato present adequation to the presupposition of
additivity of the model. Violations of the productive and morphological variables occur to the
presupposition of: normality, homogeneity and randomness of errors. The grouping of all
harvests for analysis provides adequation of productive and morphological variables to the
presuppositions of normality and homogeneity of errors. The data transformation that
provides more proportion of adequation of productive and morphological variables to the
presuppositions of normality, homogeneity and randomness of errors is the square root. In the
spring-summer, the Acrescent Solus® does not alter the productive and morphological
variables and, the quality of fruits of tomato, while, in the autumn-winter, it reduces the
length, the width and the mass of fruits and, also, it does not alters the quality of fruits. The
increase of the dose of Acrescent Solus®, combined with the mineral fertilization in coverage
results in intensification of the green color of leaves, from the second and fourth harvest fruit
in the spring-summer and autumn-winter, respectively, nevertheless, without showing
favorable correlation with the expression of productive and morphological variables of
tomato. / Os objetivos deste estudo foram: verificar o atendimento às pressuposições do modelo
matemático e, identificar transformações de dados para variáveis produtivas e morfológicas
de tomateiro em experimentos em túnel plástico e em campo, considerando cada data de
colheita e colheitas agrupadas na primavera-verão e outono-inverno; e, avaliar o efeito da
aplicação de Acrescent Solus® em complementação e/ou substituição à adubação mineral em
cobertura sobre variáveis produtivas, morfológicas, de qualidade de frutos e de coloração de
folhas de tomateiro cultivado em túnel plástico e em campo na primavera-verão e outonoinverno.
Dois experimentos foram conduzidos em túnel plástico (primavera-verão e outonoinverno)
e um em campo (primavera-verão), ambos no delineamento de blocos ao acaso com
três repetições em um bifatorial (2x4), com quatro testemunhas adicionais. Para verificar o
atendimento às pressuposições de: aditividade do modelo, normalidade, homogeneidade e
aleatoriedade dos erros foram utilizados, respectivamente, os testes de: não aditividade de
Tukey, Lilliefors, Bartlett e de Sequência. Nos casos de violação, os dados foram
transformados e, novamente submetidos à análise das pressuposições do modelo matemático.
As variáveis produtivas e morfológicas de tomateiro apresentam atendimento ao pressuposto
de aditividade do modelo. Ocorrem violações das variáveis produtivas e morfológicas às
pressuposições de: normalidade, homogeneidade e aleatoriedade dos erros. O agrupamento de
todas as colheitas para análise proporciona atendimento das variáveis produtivas e
morfológicas aos pressupostos de normalidade e homogeneidade dos erros. A transformação
que possibilita maior proporção de atendimento das variáveis produtivas e morfológicas aos
pressupostos de normalidade, homogeneidade e aleatoriedade dos erros é a raiz quadrada. Na
primavera-verão o Acrescent Solus® não influencia as variáveis produtivas, morfológicas e
de qualidade dos frutos de tomateiro, enquanto no outono-inverno reduz o comprimento, a
largura e a massa de frutos e, também não influencia a qualidade de frutos. O aumento da
dose de Acrescent Solus®, combinada com a adubação mineral em cobertura resulta em
intensificação da coloração verde das folhas, a partir da segunda e quarta colheita de frutos na
primavera-verão e outono-inverno, respectivamente, porém, sem apresentar correlação
favorável com a expressão das variáveis produtivas e morfológicas de tomateiro.
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Analysis and Modelling of Activity-Travel Behaviour of Non-Workers from an Indian CityManoj, M January 2015 (has links) (PDF)
Indian cities have been witnessing rapid transformation due to the synergistic effect of industrialisation, flourishing-economy, motorisation, population explosion, and
migration. The alarming increase in travel demand as an after effect of the
transformation, and the scarcity in transport infrastructures have exacerbated urban
transport issues such as congestion, pollution, and inequity. Due to the escalating cost of transport infrastructure and the scarcity of resources such as space, there has been an increasing interest in promoting sustainable transportation policy measures for the optimum use of existing resources. Such policy measures mostly target the activitytravel behaviour of individuals to bring about desired changes in the transport sector. However, the responses of individuals to most of the measures are complex or unknown. The current ‘commute trip-based’ aggregate travel demand analysis
strategy followed in most of the Indian cities is inadequate for providing basic inputs to understand the activity-travel behaviour of individuals under such policy
interventions. Furthermore, the current analysis strategy also ignores the activitytravel behaviour of non-workers – who include homemakers, unemployed, and retired
individuals – whose inclusion to transportation planning is relevant when the
proposed policies are mostly ‘citizen-centric’.
Analysis of activity-travel behaviour of non-workers provide important
inputs to transportation planning as their activity-travel behaviour, and responses to
transportation policies are different from that of workers. However, case studies
exploring the activity-travel behaviour of non-workers from Indian cities are very
limited. Appraising the practical importance of this subject, the current research
undertakes a comprehensive analysis of the activity-travel behaviour of non-workers
from a developing country’s context. To fulfil the goal, a series of empirical analysis are conducted on a primary activity-travel weekday survey data collected from
Bangalore city. The analysis provides insightful findings and interpretations
consistent with a developing country’s perspective.
The day-planner format of time use diary, which was observed to have satisfactory performances in developed countries, is apparently have inferior performances in a developing country’s context. Further, the face-to-face method of survey administration is observed to have higher operating and economic efficiencies compared to the drop-off and pick-up method.
The comprehensive analysis of activity-travel behaviour of non-workers indicate that comparing with their counterparts in the developed world (e.g. the U.S.),
non-workers in Bangalore city are observed to have lower activity participation level
(in terms of time allocation and number of stops), higher dependency on walking,
lower trip chaining tendency, and a distinct time-of-day preference for departing to
activity locations. On the other hand, the analysis shows similarities (mode use and
trip chaining) and differences (time allocation and departure time choice) with the findings of the case studies from the developing world (e.g. China). Activity-travel behaviour of non-workers belonging to low-income households is characterised by
lower activity participation level, higher dependency on sustainable transport modes,
and lower trip chaining propensity, compared to other two income groups (middle and
high-income groups). The research also suggests that built environment measures
have their highest impacts on non-workers’ travel decisions related to shopping.
Finally, the joint analysis of activity participation and travel behaviour of non-workers indicate that in-home maintenance activity duration drives the time allocation and travel behaviour of non-workers, and non-workers trade in-home discretionary
activity duration with travel time. The joint analysis also shows that the time spent on
children’s and elders’ activity is an important time allocation of its own.
Keywords: Activity-travel behaviour, Non-worker, Time Use, Income Groups, India
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O Problema de Riemann para um modelo matemático de escoamento trifásico com dados de injeção do tipo água-gás e dados de produção do tipo gás-óleo. / The Riemann's problem for a mathematical three-phase flow model with water-gas type injection data and gas-oil type production dataBARROS, Luciano Martins. 24 July 2018 (has links)
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Previous issue date: 2010-03 / Neste trabalho obtivemos uma solução do problema de Riemann associado a
um sistema de duas leis de conservação proveniente da modelagem matemática de
um escoamento trifásico num meio poroso. Consideramos o caso de um reservatório
petrolífero contendo inicialmente uma mistura arbitrária do tipo gás/óleo à ser deslocada
pela injeção de uma mistura do tipo água/gás, também arbitrária. Usando uma
combinação de métodos analíticos e computacionais determinamos a geometria das
chamadas curvas de onda sob a condição de entropia de viscosidade, com matriz de
viscosidade sendo a identidade. Determinamos todas as possíveis sequências de ondas
que descrevem o escoamento para cada par de misturas de injeção e de produção representandoosdadosdeRiemann.
Mostramosqueparadadosdeproduçãorepresentando
uma mistura próxima de óleo puro, ou de gás puro, apenas duas ondas estão presentes
no escoamento, independentemente da mistura de injeção. No entanto, para dados
de produção representando uma melhor proporção gás/óleo mostramos a existência de
uma faixa de dados de injeção para a qual três ondas estão presentes no escoamento,
uma delas sendo uma onda de choque transicional. / In this work we describe a Riemann solution for a system of two conservation
laws modeling a three-phase flow in a porous media. We consider the case where a
petroleum reservoir is initially filled with an arbitrary gas/oil mixture to be displaced
by the injection of a gas/water mixture, also arbitrary. By using a combination of
analytical and computational methods we obtain the geometry of the so called wave
curves under the viscous profile entropy condition, with the viscosity matrix as the
identity. We determine all wave sequences describing the flow for each pair of injection
andproductionmixtures,representingtheRiemanndata. Weshowthatforproduction
mixture data close to pure oil, or pure gas, only two waves are present in the flow
independentlyontheinjectionmixture. Nevertheless, forproductiondatarepresenting
a more proportional gas/oil mixture we show the existence of a injection data range
for which three waves are present in the flow, one of them being a transitional shock
wave.
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Modelagem e simulação dinâmica de reatores de leito fixoRodrigues, Caroline 25 February 2011 (has links)
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Previous issue date: 2011-02-25 / Universidade Federal de Sao Carlos / This work investigated numerical methods in the solution of mathematical models of fixed-bed reactors. For the reactors modeling and simulation, two numerical methods were used: sequencing method (SM) and finite volume method (FVM). There were also proposed two mathematical models: the pseudo-homogeneous model and the dimensionless one, which is based on the Peclet (Pe) and Biot (Bi) numbers. A horizontal-flow anaerobic immobilized sludge (HAIS) reactor developed in bench scale and after a scale-up, reducing the COD in the wastewater treatment was simulated by sequencing method, varying the numbers of mesh; a tubular fixed-bed reactor with biomass immobilized for the startup period of lactic acid fermentation, also simulated by sequencing method and compared with experimental data; and was also evaluated the precision of sequencing and finite volume methods over the reactor s profile, varying the Peclet e Biot numbers. The models development was based on studies about hydrodynamics and biochemistry kinetics. Both methods described satisfactorily the behavior of the reactors in the performed simulations, but in high values of Peclet, the finite volume method generated inadequacies such as oscillatory responses and over the limit. This paper is an elucidation to sequencing method, which besides its huge range and simplicity, still is not so studied neither known, because it s a recent method. / Este trabalho investigou metodos numericos na solucao de modelos matematicos para reatores de leito fixo. Para a modelagem e simulacao dos reatores, foram utilizados dois metodos numericos: metodo da sequencia (SM) e metodo dos volumes finitos (FVM). Foram propostos dois modelos matematicos: o pseudo-homogeneo e o adimensional, sendo este ultimo baseado nos numeros de Peclet (Pe) e Biot (Bi). Um reator anaerobio horizontal de leito fixo (RAHLF) desenvolvido inicialmente em escala de bancada e posterior aumento de escala na reducao da DQO de aguas residuarias foi simulado pelo metodo da sequencia, variando-se o numero de malhas; um reator tubular de leito fixo com biomassa anaerobia imobilizada no periodo da partida da fermentacao de acido latico, tambem simulado pelo metodo da sequencia e comparado com dados experimentais; e avaliou-se a precisao dos metodos da sequencia e dos volumes finitos sobre o perfil da concentracao de um reator, variando-se os valores de Peclet e Biot. O desenvolvimento dos modelos foi baseado em estudos sobre caracteristicas hidrodinamicas do sistema e de cinetica bioquimica. Ambos os metodos descreveram satisfatoriamente o comportamento dos reatores nas simulacoes realizadas, porem em valores elevados de Peclet, o metodo dos volumes finitos gerou inadequacoes como respostas oscilatorias e superiores ao limite. Este trabalho foi uma elucidacao ao metodo da sequencia, que apesar da sua grande abrangencia e simplicidade, por ser um metodo recente, ainda e pouco estudado e conhecido.
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Uma modelagem da máquina síncrona considerando o efeito da curvatura da sapata polarAlves, Aylton José 15 April 2011 (has links)
This work develops a new mathematical model to the salient pole synchronous machines
(SPSM), based on the abc reference system. The model considers the distribution
and coil pitch factors of windings and develops a new function for the variable
air gap, generated by the curvature of the polar mass. As a result, the development
of the modeling takes into account the spatial harmonic components of: magneto
motive force MMF(θ)h, electromagnetic
ux density B(θ)h and variation function
of the air gap g(θ)h.
It is also proposed a new and simplied methodology using the locked rotor tests,
volt-ampere method, to obtain the constants of the synchronous machine design,
which allow the calculation of the modeling parameters and the terminals magnitudes
determination. It presents also contributions to traditional methods of obtaining
experimental inductances, using the locked rotor test. Yet it develops procedures
and makes the simulation of the main temporal magnitudes at the generator terminals
connected to the utility grid, electrical torque, speed, voltage and current.
The model is validated through the theoretical and experimental confrontation
of inductances, and also of the voltages and currents at the generator terminals
connected to the utility grid. / Este trabalho desenvolve uma nova modelagem matemática para as máquinas síncronas
de polos salientes (MSPS), baseada no sistema abc de referência. A modelagem
considera os fatores de distribuição e de passo de bobina dos enrolamentos
e desenvolve uma nova função para o entreferro variável, gerado pela curvatura da
sapata polar. Como conseqüência o desenvolvimento da modelagem leva em consideração os componentes harmônicos espaciais de: força magneto motriz FMM(θ)h,
densidade de uxo eletromagnético B(θ)h e da função de variação do entreferro
g(θ)h.
É também proposto uma nova e simplificada metodologia a partir dos testes de
rotor bloqueado, método volt-ampere, para a obtenção das constantes de projeto da
máquina síncrona que possibilitam os cálculos dos parâmetros da modelagem, bem
como a determinação das grandezas terminais. Também apresenta contribuições aos
métodos tradicionais de obtenção de indutâncias experimentais, a partir dos testes de
rotor bloqueado. Ainda desenvolve os procedimentos e faz a simulação das principais
grandezas temporais nos terminais do gerador conectado à rede da concessionária:
torque elétrico, velocidade, corrente e tensão.
A modelagem é convalidada através das confrontações teórico-experimental das
indutâncias, e também dos resultados de correntes e tensões nos terminais do
gerador conetado à rede da concessionária. / Doutor em Ciências
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ANA-PSp: um sistema computacional para análise aeroelástica de pontes suspensas por modelos matemáticos reduzidos. / Ana-PSp: a computational system for aeroelastic analysis of suspended bridges for reduced mathematical models.Eri Sato Kreis 22 November 2007 (has links)
As características arquitetônicas e o desempenho estrutural de pontes suspensas, estaiadas ou pênseis, têm determinado a sua crescente utilização em obras de arte destinadas a vencer grandes vãos. Essa utilização crescente que ocorreu no mundo nas últimas décadas se repete agora nos últimos anos no país. Várias dessas obras estão em execução e em projeto. Um dos aspectos relevantes na análise estrutural das pontes suspensas é o de seu comportamento quando submetidas à ação do vento. Apresenta-se o sistema computacional ANA-PSp desenvolvido especialmente para o estudo do movimento de tabuleiros de pontes suspensas sujeitas a esforços aeroelásticos e aerodinâmicos. Esse sistema computacional formado por um conjunto de subsistemas, é elaborado para a análise aeroelástica de pontes suspensas sob a ação de vento e permite análises paramétricas extensas dos fenômenos de drapejamento (flutter) e de martelamento (buffeting). A discretização da estrutura é efetuada pelo método dos elementos finitos e a redução dos graus de liberdade é realizada por superposição modal com modos selecionados que melhor descrevem os movimentos do tabuleiro. Utiliza-se modelo matemático reduzido para a análise multimodal no domínio do tempo e da freqüência. A velocidade crítica ou velocidade de drapejamento é determinada por procedimento de autovalores complexos com a obtenção de freqüências e taxas de amortecimentos modais para várias velocidades do vento. Adicionalmente, o fenômeno do drapejamento é estudado por séries temporais de respostas de coordenadas generalizadas e de deslocamentos selecionados e por análise espectral dessas séries temporais, que permitem a verificação das características de vibração do tabuleiro da ponte no domínio da freqüência. O estudo do fenômeno de martelamento considera esforços aeroelásticos determinísticos e esforços aerodinâmicos estocásticos e apresentam-se resultados em espectros de potência de deslocamentos e em desvios padrão de deslocamentos ao longo do tabuleiro. Para validar o sistema ANA-PSp, apresentam-se estudos de caso para a ponte estaiada da Normandia, para a ponte pênsil colapsada de Tacoma Narrows e para a ponte estaiada projetada, mas não executada, sobre o Rio Tietê e localizada na extremidade do complexo viário Jacu-Pêssego. / The architectonic characteristics and the structural performance of suspension bridges and cable-stayed bridges have determined their growing use on large span bridges. This growing usage, which has occurred world-wide during the last decades, is now being repeated in Brazil during the last few years. Several such bridges are presently either undergoing construction or being designed. One of the outstanding aspects in the structural analysis of suspension bridges is their behavior under wind action. This paper presents the computer system ANA-PSp, specially developed for studying the movement of suspended bridge decks under aeroelastic and aerodynamic forces. This computer system is formed by a group of subsystems and is created for aeroelastic analysis of suspended bridges under wind action. It allows extended parametric analyses of the flutter and the buffeting phenomena. Structural discretization is done by the finite element method and the reduction of degrees of freedom is obtained by modal superposition of the selected modes which best describe the deck movements. A reduced mathematical model is used for the multimodal analysis in the time and frequency domains. Critical velocity or flutter velocity is determined by a procedure of complex eigenvalues which obtains frequencies and damping ratios for different wind speeds. Additionally, the flutter phenomenon is studied by temporal series of answers to generalized coordinate responses and of selected displacements by spectral analysis of such temporal series, which allow us to verify the characteristics of the vibrations of the bridge deck in the frequency domain. The study of the buffeting phenomenon considers deterministic aeroelastic and stochastic aerodynamic forces. The paper presents results in displacement power spectra and in the standard deviation of displacements along the deck. In order to validate system ANA-PSp, case studies are presented for the cable-stayed Ponte de Normandie in Le Havre (France), for the collapsed suspension bridge on Tacoma Narrows and for the cable-stayed bridge, already designed but not built, on Tietê River, located at one end of the highway complex Jacu-Pêssego (São Paulo, SP, Brazil).
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O problema integrado de dimensionamento e sequenciamento de lotes no processo de fabricação da cerveja: modelos e métodos de solução / The integrated lot sizing and scheduling problem in the brewing process: models and solution methodsTamara Angélica Baldo 19 August 2014 (has links)
Este trabalho aborda o problema multiestágio de planejamento e programação da produção em indústrias cervejeiras. O processo de fabricação de cerveja pode ser dividido em duas etapas principais: preparação do líquido e envase. A primeira etapa ocorre, na maior parte do tempo, dentro de tanques de fermentação e maturação. A segunda ocorre nas linhas de envase, podendo ter início assim que o líquido estiver pronto nos tanques. O tempo de preparação do líquido demora vários dias, enquanto que na maioria das indústrias de bebidas carbonatadas este tempo é de no máximo algumas horas. O objetivo deste estudo é obter planos de produção viáveis que visam otimizar as decisões de programação envolvidas nestes processos. Visitas a cervejarias no Brasil e em Portugal foram realizadas para uma maior familiaridade do processo de produção e dados foram coletados. Modelos de programação inteira mista para representar o problema foram desenvolvidos, baseados em abordagens CSLP (The Continuous Setup Lot-Sizing Problem), GLSP (General Lot Sizing and Scheduling Problem), SPL (Simple Plant Location Problem) e ATSP (Asymmetric Travelling Salesman Problem). Os resultados mostram que os modelos são coerentes e representam adequadamente o problema, entretanto, mostram-se difíceis de serem resolvidos na otimalidade. Esta dificuldade de resolução dos modelos motivou o desenvolvimento de procedimentos MIP-heurísticos, como também de uma metaheurística GRASP (Greedy Randomized Adaptive Search Procedure). As soluções obtidas pelos procedimentos heurísticos são de boa qualidade, quando comparadas ao melhor limitante inferior encontrado por meio da resolução dos modelos matemáticos. Os testes computacionais foram realizados utilizando instâncias geradas com base em dados reais. / This study deals with the multistage lot-sizing and scheduling problem in breweries. The brewing process can be divided into two main stages: preparation and filling of the liquid. The first stage occurs most of the time in fermentation and maturation tanks. The second stage occurs in the filling lines and it can start as soon as the liquid gets ready. The preparation time of the liquid takes several days, while in the carbonated beverage industries this time is at most a few hours. The purpose of this study is to obtain feasible production plans aimed at optimizing the decisions involved in these processes. Visits to brewery industries in Brazil and Portugal were held to a greater familiarity of the production process and data were collected. Mixed integer programming models have been developed to represent the problem, based on approaches for the CSLP (The Continuous Setup Lot-Sizing Problem), GLSP (General Lot Sizing and Scheduling Problem), SPL (Simple Plant Location Problem) and ATSP (Asymmetric Travelling Salesman Problem). The results show that the models are consistent and adequately represent the problem; however, they are difficult to be solved at optimality. This motivated the development of MIP-heuristic procedures, as well as a meta-heuristic GRASP (Greedy Randomized Adaptive Search Procedure). The obtained solutions by the heuristics are of good quality, when compared to the best lower bound found by solving the mathematical models. The tests were conducted using generated instances based on real data.
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