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Maritime Transportation Optimization Using Evolutionary Algorithms in the Era of Big Data and Internet of ThingsCheraghchi, Fatemeh 19 July 2019 (has links)
With maritime industry carrying out nearly 90% of the volume of global trade, the algorithms and solutions to provide quality of services in maritime transportation are of great importance to both academia and the industry. This research investigates an optimization problem using evolutionary algorithms and big data analytics to address an important challenge in maritime disruption management, and illustrates how it can be engaged with information technologies and Internet of Things. Accordingly, in this thesis, we design, develop and evaluate methods to improve decision support systems (DSSs) in maritime supply chain management.
We pursue three research goals in this thesis. First, the Vessel Schedule recovery Problem (VSRP) is reformulated and a bi-objective optimization approach is proposed. We employ bi-objective evolutionary algorithms (MOEAs) to solve optimization problems. An optimal Pareto front provides a valuable trade-off between two objectives (minimizing delay and minimizing financial loss) for a stakeholder in the freight ship company. We evaluate the problem in three
domains, namely scalability analysis, vessel steaming policies, and voyage distance
analysis, and statistically validate their performance significance. According to the experiments, the problem complexity varies in different scenarios, while NSGAII
performs better than other MOEAs in all scenarios.
In the second work, a new data-driven VSRP is proposed, which benefits from the available Automatic Identification System (AIS) data. In the new formulation, the trajectory between the port calls is divided and encoded into adjacent geohashed regions. In each geohash, the historical speed profiles are extracted from AIS data. This results in a large-scale optimization problem called G-S-VSRP with three objectives (i.e., minimizing loss, delay, and maximizing compliance) where the compliance objective maximizes the compliance of optimized speeds with the historical data. Assuming that the historical speed profiles are reliable to trust for actual operational speeds based on other ships' experience, maximizing the compliance of optimized speeds with these historical data offers some degree of avoiding risks. Three MOEAs tackled the problem and provided the stakeholder with a Pareto front which reflects the trade-off among the three objectives. Geohash granularity and dimensionality reduction techniques were evaluated and discussed for the model. G-S-VSRPis a large-scale optimization problem and suffers from the curse of dimensionality (i.e. problems are difficult to solve due to exponential growth in the size of the multi-dimensional solution space), however, due to a special characteristic of the problem instance, a large number of function evaluations in MOEAs can still find a good set of solutions.
Finally, when the compliance objective in G-S-VSRP is changed to minimization, the regular MOEAs perform poorly due to the curse of dimensionality. We focus on improving the performance of the large-scale G-S-VSRP through a novel distributed multiobjective cooperative coevolution algorithm (DMOCCA). The proposed DMOCCA improves the quality of performance metrics compared to the regular MOEAs (i.e. NSGAII, NSGAIII, and GDE3). Additionally, the DMOCCA results in speedup when running on a cluster.
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Sistemática para alocação, sequenciamento e balanceamento de lotes em múltiplas linhas de produçãoPulini, Igor Carlos January 2018 (has links)
Diante dos desafios impostos pelo sistema econômico, características dos mercados e exigências dos clientes, as empresas são forçadas a operar com lotes de produção cada vez menores, dificultando a gestão de operações e a otimização dos sistemas produtivos. Desse modo, intensifica-se nos meios corporativos e acadêmicos a busca por abordagens que possibilitem a criação de diferenciais competitivos de mercado, sendo esta a justificativa prática deste trabalho, que propõe uma sistemática integrada para alocação, sequenciamento e balanceamento de lotes em um horizonte de programação em múltiplas linhas de produção em um sistema multiproduto com operadores polivalentes. A sistemática proposta foi dividida em três fases. A primeira fase utiliza um algoritmo genético multiobjetivo com o intuito de determinar a linha de produção em que cada lote será produzido. A segunda fase é responsável pelo sequenciamento dos lotes produtivos e se apoia em uma alteração da regra Apparent Tardiness Cost (ATC). Na terceira fase utilizou-se o método Ranked Positional Weight (RPW) para balancear a distribuição das tarefas entre os operadores polivalentes de cada linha de produção, respeitando a precedência das tarefas. A sistemática foi aplicada em dados reais do segmento têxtil, aprimorando os indicadores produtivos e de entrega e conferindo maior flexibilidade ao processo frente à demanda sazonal. / Faced with the challenges imposed by the economic system, characteristic of the markets and requirements of the customers, the companies are forced to operate with smaller production batches, making it difficult to manage operations and optimization of the production systems. In this way, the search for improvements that allow the creation of competitive differentials of market is intensified in the corporate and academic circles. This is the practical justification for this work, which proposes an integrated systematics for the allocation, sequencing and balancing of batches in a horizon of programming in multiple production lines in a multiproduct system with multipurpose operators. The systematic proposal was divided into three phases. The first phase uses a multiobjective genetic algorithm with intention to determine the production line in which each batch will be produced. The second phase is responsible for the sequencing of productive batches and is based on a change in the rule Apparent Tardiness Cost (ATC). In the third phase the method Ranked Positional Weight (RPW) was used to balance the distribution of the tasks between the multipurpose operators of each line of production, respecting the precedence of the tasks. The systematics was applied in real data of the textile segment, improving the productive and delivery indicators and giving greater flexibility of the process against the seasonal demand.
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Extração de regras operacionais ótimas de sistemas de distrubuição de água através de algoritmos genéticos multiobjetivo e aprendizado de máquina / Extraction of optimal operation rules of the water distribution systems using multiobjective genetic algorithms and machine learningCarrijo, Ivaltemir Barros 10 December 2004 (has links)
A operação eficiente do sistema é uma ferramenta fundamental para que sua vida útil se prolongue o máximo possível, garantindo o perfeito atendimento aos consumidores, além de manter os custos com energia elétrica e manutenção dentro de padrões aceitáveis. Para uma eficiente operação, é fundamental o conhecimento do sistema, pois, através deste, com ferramentas como modelos de simulação hidráulica, otimização e definição de regras, é possível fornecer ao operador condições de operacionalidade das unidades do sistema de forma racional, não dependendo exclusivamente de sua experiência pessoal, mantendo a confiabilidade do mesmo. Neste trabalho é desenvolvido um modelo computacional direcionado ao controle operacional ótimo de sistemas de macro distribuição de água potável, utilizando um simulador hidráulico, um algoritmo de otimização, considerando dois objetivos (custos de energia elétrica e benefícios hidráulicos) e um algoritmo de aprendizado para extração de regras operacionais para o sistema. Os estudos foram aplicados no sistema de macro distribuição da cidade de Goiânia. Os resultados demonstraram que podem ser produzidas estratégias operacionais satisfatórias para o sistema em substituição ao julgamento pessoal do operador. / The efficient operation of a system is a fundamental tool to postpone the systems service life as much as possible, thus ensuring a good service to the consumer while keeping electrical energy and maintenance costs at acceptable levels. Efficient operation requires knowledge of the system, for this knowledge, supported by tools such as models for hydraulic simulation, optimization, and definition of rules, provides the operator with proper conditions for the rational operating of the systems units without depending exclusively on personal experience while maintaining the systems reliability. In this work is developed a computational model for the optimal operation control of macro water distribution systems using a hydraulic simulator, an optimization algorithm, and a learn algorithm to extract operational rules (strategies) for the system. These studies are to be based on the macro system of the city of Goiânia, in Brazil. The results show that solutions for satisfactory operation can be quickly produced as a substitute to the personal judgment of the operator.
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Algoritmos evolutivo multiobjetivo para seleção de variáveis em problemas de calibração multivariada / Multiobjective evolutionary algorithms for vari- ables selection in multivariate calibration problemsLucena, Daniel Vitor de 03 May 2013 (has links)
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Previous issue date: 2013-05-03 / This work proposes the use of multi-objective genetics algorithms NSGA-II and SPEA-II
on the variable selection in multivariate calibration problems. These algorithms are used
for selecting variables for a Multiple Linear Regression (MLR) by two conflicting objectives:
the prediction error and the used variables number in MLR. For the case study
are used wheat data obtained by NIR spectrometry with the objective for determining a
variable subgroup with information about protein concentration. The results of traditional
techniques of multivariate calibration as the Partial Least Square (PLS) and Successive
Projection Algorithm (SPA) for MLR are presents for comparisons. The obtained
results showed that the proposed approach obtained better results when compared with
a monoobjective evolutionary algorithm and with traditional techniques of multivariate
calibration. / Este trabalho propõe a utilização dos algoritmos genéticos multiobjetivo NSGA-II e
SPEA-II na seleção de variáveis em problemas de calibração multivariada. Esses algoritmos
são utilizados para selecionar variáveis para Regressão Linear Múltipla (MLR)
com dois objetivos conflitantes: o erro de predição e do número de variáveis utilizadas na
MLR. Para o estudo de caso são usado dados de trigo obtidos por espectrometria NIR com
o objetivo de determinar um subgrupo de variáveis com informações sobre a concentração
de proteína. Os resultados das técnicas tradicionais de calibração multivariada como dos
Mínimos Quadrados Parciais (PLS) e Algoritmo de Projeções Sucessivas (APS) para a
MLR estão presentes para comparações. Os resultados obtidos mostraram que a abordagem
proposta obteve melhores resultados quando comparado com um algoritmo evolutivo
monoobjetivo e com as técnicas tradicionais de calibração multivariada.
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Application of Multiobjective Optimization in Chemical Engineering Design and OperationFettaka, Salim 24 August 2012 (has links)
The purpose of this research project is the design and optimization of complex chemical engineering problems, by employing evolutionary algorithms (EAs). EAs are optimization techniques which mimic the principles of genetics and natural selection. Given their population-based approach, EAs are well suited for solving multiobjective optimization problems (MOOPs) to determine Pareto-optimal solutions. The Pareto front refers to the set of non-dominated solutions which highlight trade-offs among the different objectives. A broad range of applications have been studied, all of which are drawn from the chemical engineering field. The design of an industrial packed bed styrene reactor is initially studied with the goal of maximizing the productivity, yield and selectivity of styrene. The dual population evolutionary algorithm (DPEA) was used to circumscribe the Pareto domain of two and three objective optimization case studies for three different configurations of the reactor: adiabatic, steam-injected and isothermal. The Pareto domains were then ranked using the net flow method (NFM), a ranking algorithm that incorporates the knowledge and preferences of an expert into the optimization routine. Next, a multiobjective optimization of the heat transfer area and pumping power of a shell-and-tube heat exchanger is considered to provide the designer with multiple Pareto-optimal solutions which capture the trade-off between the two objectives. The optimization was performed using the fast and elitist non-dominated sorting genetic algorithm (NSGA-II) on two case studies from the open literature. The algorithm was also used to determine the impact of using discrete standard values of the tube length, diameter and thickness rather than using continuous values to obtain the optimal heat transfer area and pumping power. In addition, a new hybrid algorithm called the FP-NSGA-II, is developed in this thesis by combining a front prediction algorithm with the fast and elitist non-dominated sorting genetic algorithm-II (NSGA-II). Due to the significant computational time of evaluating objective functions in real life engineering problems, the aim of this hybrid approach is to better approximate the Pareto front of difficult constrained and unconstrained problems while keeping the computational cost similar to NSGA-II. The new algorithm is tested on benchmark problems from the literature and on a heat exchanger network problem.
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Global optimization applied to kinetic models of metabolic networksPozo Fernández, Carlos 27 November 2012 (has links)
Recientemente, el uso de técnicas de manipulación genética ha abierto la puerta a la obtención de microorganismos con fenotipos mejorados, lo que a su vez ha llevado a unas mejoras significativas en la síntesis de algunos productos bioquímicos. Sin embargo, la mutación y selección de estos nuevos organismos se ha llevado a cabo, en la mayoría de casos, por ensayo y error. Es de esperar que estos procesos puedan ser mejorados si se usan principios de diseño cuantitativos para guiar la búsqueda hacia el perfil enzimático ideal. Esta tesis está dedicada al desarrollo de un conjunto de herramientas de optimización avanzadas para asesorar en problemas de ingeniería metabólica y otras cuestiones emergentes en biología de sistemas. Concretamente, nos centramos en problemas en qué se modelan las redes metabólicas usando expresiones cinéticas. La utilidad de los algoritmos desarrollados para resolver tales problemas es demostrada por medio de varios casos de estudio. / In recent years, the use of genetic manipulation techniques has opened the door for obtaining microorganisms with enhanced phenotypes, which has in turn led to significant improvements in the synthesis of certain biochemical products. However, mutation and selection of these new organisms has been performed, in most cases, in a trial-and-error basis. It is expected that these processes could be further improved if quantitative design principles were used to guide the search towards the ideal enzymatic profiles. This thesis is devoted to developing a set of advanced global optimization tools to assess metabolic engineering problems and other questions arising in systems biology. In particular, we focus on problems where metabolic networks are modeled making use of kinetic expressions. The usefulness of the algorithms developed to solve such problems is demonstrated by means of several case studies.
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Exon Primers Design Using Multiobjective Genetic AlgorithmHuang, Erh-chien 29 August 2005 (has links)
Exons are expression DNA sequences. A DNA sequence which includes gene has exons and introns. During transcription and translation, introns will be removed, and exons will remain to become protein. Many researchers need exon primers for PCR experiments. However, it is a difficult to find that many exon primers satisfy all primer design constraints at the same time. Here, we proposed an efficient exon primer design algorithm. The algorithm applies multiobjective genetic algorithm (MGA) instead of the single objective algorithm which can easily lend to unsuitable solutions. And a hash-index algorithm is applied to make specificity checking in a reasonable time. The algorithm has tested by a variety of mRNA sequences. These dry dock experiments show that our proposed algorithm can find primers which satisfy all exon primer design constraints.
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Preference-based Flexible Multiobjective Evolutionary AlgorithmsKarahan, Ibrahim 01 June 2008 (has links) (PDF)
In this study,we develop an elitist multiobjective evolutionary algorithm for approximating the Pareto-optimal frontiers of multiobjective optimization problems. The algorithm converges the true Pareto-optimal frontier while keeping the solutions in the population well-spread over the frontier. Diversity of the solutions is maintained by the territory de& / #64257 / ning property of the algorithm rather than using an explicit diversity preservation mechanism. This leads to substantial computational e& / #64259 / ciency. We test the algorithm on commonly used test problems and compare its performance against well-known benchmark algorithms.
In addition to approximating the entire Pareto-optimal frontier,we develop a preference incorporation mechanism to guide the search towards the decision maker& / #8217 / s regions of interest. Based on this mechanism, we implement two variants of the algorithm. The & / #64257 / rst gathers all preference information before the optimization stage to & / #64257 / nd approximations of the desired regions. The second one is an interactive algorithm that focuses on the desired region by interacting with the decision maker during the solution process. Based on tests on 2- and 3-objective problems, we observe that both algorithms converge to the preferred regions.
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An Interactive Preference Based Multiobjective Evolutionary Algorithm For The Clustering ProblemDemirtas, Kerem 01 May 2011 (has links) (PDF)
We propose an interactive preference-based evolutionary algorithm for the clustering problem. The problem is highly combinatorial and referred to as NP-Hard in the literature. The goal of the problem is putting similar items in the same cluster and dissimilar items into different clusters according to a certain similarity measure, while maintaining some internal objectives such as compactness, connectivity or spatial separation. However, using one of these objectives is often not sufficient to detect different underlying structures in different data sets with clusters having arbitrary shapes and density variations. Thus, the current trend in the clustering literature is growing into the use of multiple objectives as the inadequacy of using a single objective is understood better. The problem is also difficult because the optimal solution is not well defined. To the best of our knowledge, all the multiobjective evolutionary algorithms for the clustering problem try to generate the whole Pareto optimal set. This may not be very useful since majority of the solutions in this set may be uninteresting when presented to the decision maker. In this study, we incorporate the preferences of the decision maker into a well known multiobjective evolutionary algorithm, namely SPEA-2, in the optimization process using reference points and achievement scalarizing functions to find the target clusters.
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Bi-objective Bin Packing ProblemsIlicak, Isil 01 December 2003 (has links) (PDF)
In this study, we consider two bi-objective bin packing problems that assign a number of weighted items to bins having identical capacities.
Firstly, we aim to minimize total deviation over bin capacity and minimize number of bins. We show that these two objectives are conflicting. Secondly, we study the problem of minimizing maximum overdeviation and minimizing the number of bins. We show the similarities of these two problems to parallel machine scheduling problems and benefit from the results while developing our solution approaches. For both problems, we propose exact procedures that generate efficient solutions relative to two objectives. To increase the efficiency of the solutions, we propose some lower and upper bounding procedures. The
results of our experiments show that total overdeviation problem is easier to solve compared to maximum overdeviation problem and the bin capacity, the weight of items and the number of items are important factors that effect the solution time and quality. Our procedures can solve the problems with up to 100 items in reasonable solution times.
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