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PINHEIRO, SAULO BORGES. "CONTAINERS ROAD TRANSPORTATION OPTIMIZATION: EXACT AND HEURISTICS METHODS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2013. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=34991@1.
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Apesar da dimensão continental brasileira, da grandeza de sua costa e da proximidade entre o litoral e os grandes centros urbanos, o transporte de cargas em contêineres utilizando a cabotagem ainda é muito restrito no Brasil. Neste cenário, para ganhar espaço, os armadores brasileiros de cabotagem buscam oferecer serviços porta-a-porta, conseguindo economias de escala na contratação dos fornecedores que realizam as pontas rodoviárias, aumentando assim a competitividade da cabotagem com seu principal concorrente, o modal rodoviário. Neste trabalho são apresentados dois modelos que visam minimizar o custo total de contratação de fornecedores rodoviários para uma lista de demandas que devem ser atendidas. O primeiro é um modelo matemático de programação linear inteira, o segundo é um algoritmo que utiliza uma heurística gulosa. Os modelos foram desenvolvidos e testados em cenários reais, vividos por armador de cabotagem brasileiro durante um período de tempo determinado. Os resultados dos dois modelos, que são comparados entre si e com as soluções realizadas manualmente por funcionários do armador de cabotagem, mostram que as soluções dos modelos de otimização são muito melhores do que as soluções manuais. Os resultados mostram ainda que o algoritmo guloso alcança resultados muito próximos aos do método exato, mostrando ser de grande utilidade dada a facilidade de sua implantação.Despite the Brazilian continental scale, the magnitude of its coastline and the proximity between the coast and the large urban centers, the transport of cargo in containers using cabotage is still very limited in Brazil. In this scenario, the Brazilian cabotage ship-owners seek to provide door-to-door services, achieving economies of scale in procurement for suppliers that perform road ends, thus increasing the competitiveness of cabotage with its main competitor, the transportation by trucks. This work presents two models that aim to minimize the total cost of hiring road suppliers to a list of demands that must be performed. The first is a mathematical model based on integer linear programming, the second is an algorithm that uses a greedy heuristic. The models were developed and tested in real scenarios, experienced by a Brazilian cabotage ship-owner for a period of time. The results of the two models, which are compared among each other and with the manually solutions performed by the company’s employees, show that the solutions of optimization models are much better than the manual solutions. The results also show that the greedy algorithm achieves very close results to the exact method, proving to be very useful given the ease of its implementation.
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Panthulu, Pradeep. "Intelligent Memory Management Heuristics." Thesis, University of North Texas, 2003. https://digital.library.unt.edu/ark:/67531/metadc4399/.
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Automatic memory management is crucial in implementation of runtime systems even though it induces a significant computational overhead. In this thesis I explore the use of statistical properties of the directed graph describing the set of live data to decide between garbage collection and heap expansion in a memory management algorithm combining the dynamic array represented heaps with a mark and sweep garbage collector to enhance its performance. The sampling method predicting the density and the distribution of useful data is implemented as a partial marking algorithm. The algorithm randomly marks the nodes of the directed graph representing the live data at different depths with a variable probability factor p. Using the information gathered by the partial marking algorithm in the current step and the knowledge gathered in the previous iterations, the proposed empirical formula predicts with reasonable accuracy the density of live nodes on the heap, to decide between garbage collection and heap expansion. The resulting heuristics are tested empirically and shown to improve overall execution performance significantly in the context of the Jinni Prolog compiler's runtime system.
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Floriani, Lauro. "Multivariate statistical methods for studying the mechanics of heuristics." Nice, 2002. http://www.theses.fr/2002NICE5705.
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Les algorithmes constituent la plus efficace base de connaissances conçue par l'homme jusqu'à présent. La NP-completude indique que parmi l'ensemble des problèmes décidables il y en a que nous ne savons pas traiter de manière efficace, c. -à-d. Nous ne savons pas concevoir des algorithmes efficaces pour eux. Cependant, la pratique montre que beaucoup d'algorithmes sont quand même efficaces pour résoudre ces problèmes. C'est à dire que l'analyse expérimentale de leur relation entrée/sortie révèle une bien meilleure situation que ce qui peut être déduit d'une analyse mathématique des propriétés de ces algorithmes. Cela signifie également que le processus dynamique induit par l'algorithme (i. E. Le processus informatique) dépasse notre capacité d'expression et de communication du savoir que nous incluons dans un tel algorithme. Sans la mise en oeuvre effective de l'algorithme, nous ne serions pas capables de prédire son comportement de manière juste. Le travail de cette thèse concerne de tels processus dynamiques. Plutôt que d'analyser la connaissance que nous introduisons dans un algorithme, nous voulons étudier les mécanismes de ce processus informatique afin de déduire la connaissance qu'il contient. C'est ce que nous appelons "études exploratoires" car nous voulons acquérir de nouvelles connaissances sur le traitement du problème fourni par notre algorithme. Nous abordons ce sujet dans une perspective d'analyse de données. Notre méthode consiste à analyser le processus informatique dans sa recherche de tendances statistiques tangibles quant a sa mécanique. Afin de garantir l'aspect tangible de ces tendances, il est essentiel qu'elles rendent compte d'un processus informatique pertinent, c'est à dire reposant sur un grand nombre de données. L'analyse des données est donc un point crucial dans ce type d'études. Dans ce travail, nous présentons une application systématique des techniques statistiques d'analyse descriptive afin de mettre en évidence statistiquement les mécanismes des processus informatiques induits par les algorithmes heuristiques pour les problèmes d'optimisation difficiles. Nous présentons une étude de cas sur une heuristique à l'état de l'art sur le problème du voyageur de commerce dans laquelle nous interprétons et discutons les tendances mises en évidence par notre étude. La motivation pratique sous jacente à ce travail est l'optimisation dans le cadre du design des réseaux radio mobiles. Un contexte si particulier pose de lourdes contraintes quant a l'analyse des algorithmes, même par des expérimentations traditionnellesAlgorithms are the most effective knowledge repositories yet conceived by mankind for they automate computations on a given formal medium, the computer system. NP-Completeness tell us that among the computable treatable problems there are some which we do not know an efficient way of dealing with, i. E. We do not know how to conceive efficient algorithms for them. Nevertheless, practical experience tells us that many algorithms for these problems are indeed quite effective. That is to say that the experimental analysis of their input/output relationship reveal a far better situation than what can be derived by the mathematical analysis of these algorithms' properties. It also means that the dynamic process induced by the algorithm (i. E. The computational process) exceeds our capacity of express and communicate the knowledge we embed in such algorithm. Without the actual implementation of the algorithm we would not be able to tell their behavior. The work in this thesis concerns such dynamic process. Rather than analyze the properties of the knowledge we represent on an algorithm, we want to investigate the mechanics of the computational process in order to infer the knowledge behind it. That is what we call exploratory studies, for we want to acquire new knowledge about the treatment given by our algorithm to the problem. We approach this matter by a data analysis perspective. Our method consists on probing the computational process in search for insightful statistical evidences about its mechanics. In order to guarantee the insightful aspect of these evidences it is essential that they report on a pertinent computational process, i. E. For large input problems. Data analysis is therefore a crucial issue in such kind of study. In this work we present a systematic application of Multivariate Descriptive Statistical Analysis techniques to raise statistical evidences on the mechanics of the computational process induced by heuristic algorithms for hard optimization problems. We present a case study of a state of the art heuristic for the Traveling Salesman Problem where we interpret and discuss the evidences raised by our studies, showing their ability to provide us new knowledge about the heuristic. The practical motivation behind this work is the optimization context defined by the design of wireless telecommunications networks. Such a peculiar context poses severe constraints to the analysis of algorithms even by traditional experimentation
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Amir-Hussin, Amir A. B. "Heuristic methods for coalition structure generation." Thesis, Loughborough University, 2017. https://dspace.lboro.ac.uk/2134/26275.
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The Coalition Structure Generation (CSG) problem requires finding an optimal partition of a set of n agents. An optimal partition means one that maximizes global welfare. Computing an optimal coalition structure is computationally hard especially when there are externalities, i.e., when the worth of a coalition is dependent on the organisation of agents outside the coalition. A number of algorithms were previously proposed to solve the CSG problem but most of these methods were designed for systems without externalities. Very little attention has been paid to finding optimal coalition structures in the presence of externalities, although externalities are a key feature of many real world multiagent systems. Moreover, the existing methods, being non-heuristic, have exponential time complexity which means that they are infeasible for any but systems comprised of a small number of agents. The aim of this research is to develop effective heuristic methods for finding optimal coalition structures in systems with externalities, where time taken to find a solution is more important than the quality of the solution. To this end, four different heuristics methods namely tabu search, simulated annealing, ant colony search and particle swarm optimisation are explored. In particular, neighbourhood operators were devised for the effective exploration of the search space and a compact representation method was formulated for storing details about the multiagent system. Using these, the heuristic methods were devised and their performance was evaluated extensively for a wide range of input data.
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Remde, Stephen Mark. "Enhancing the performance of search heuristics : variable fitness functions and other methods to enhance heuristics for dynamic workforce scheduling." Thesis, University of Bradford, 2009. http://hdl.handle.net/10454/4310.
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Scheduling large real world problems is a complex process and finding high quality solutions is not a trivial task. In cooperation with Trimble MRM Ltd., who provide scheduling solutions for many large companies, a problem is identified and modelled. It is a general model which encapsulates several important scheduling, routing and resource allocation problems in literature. Many of the state-of-the-art heuristics for solve scheduling problems and indeed other problems require specialised heuristics tailored for the problem they are to solve. While these provide good solutions a lot of expert time is needed to study the problem, and implement solutions. This research investigates methods to enhance existing search based methods. We study hyperheuristic techniques as a general search based heuristic. Hyperheuristics raise the generality of the solution method by using a set of tools (low level heuristics) to work on the solution. These tools are problem specific and usually make small changes to the problem. It is the task of the hyperheuristic to determine which tool to use and when. Low level heuristics using exact/heuristic hybrid method are used in this thesis along with a new Tabu based hyperheuristic which decreases the amount of CPU time required to produce good quality solutions. We also develop and investigate the Variable Fitness Function approach, which provides a new way of enhancing most search-based heuristics in terms of solution quality. If a fitness function is pushing hard in a certain direction, a heuristic may ultimately fail because it cannot escape local minima. The Variable Fitness Function allows the fitness function to change over the search and use objective measures not used in the fitness calculation. The Variable Fitness Function and its ability to generalise are extensively tested in this thesis. The two aims of the thesis are achieved and the methods are analysed in depth. General conclusions and areas of future work are also identified.
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Remde, Stephen M. "Enhancing the Performance of Search Heuristics. Variable Fitness Functions and other Methods to Enhance Heuristics for Dynamic Workforce Scheduling." Thesis, University of Bradford, 2009. http://hdl.handle.net/10454/4310.
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Scheduling large real world problems is a complex process and finding high quality
solutions is not a trivial task. In cooperation with Trimble MRM Ltd., who provide
scheduling solutions for many large companies, a problem is identified and modelled. It
is a general model which encapsulates several important scheduling, routing and
resource allocation problems in literature. Many of the state-of-the-art heuristics for
solve scheduling problems and indeed other problems require specialised heuristics
tailored for the problem they are to solve. While these provide good solutions a lot of
expert time is needed to study the problem, and implement solutions.
This research investigates methods to enhance existing search based methods.
We study hyperheuristic techniques as a general search based heuristic. Hyperheuristics
raise the generality of the solution method by using a set of tools (low level heuristics)
to work on the solution. These tools are problem specific and usually make small
changes to the problem. It is the task of the hyperheuristic to determine which tool to
use and when. Low level heuristics using exact/heuristic hybrid method are used in this
thesis along with a new Tabu based hyperheuristic which decreases the amount of CPU
time required to produce good quality solutions. We also develop and investigate the
Variable Fitness Function approach, which provides a new way of enhancing most
search-based heuristics in terms of solution quality. If a fitness function is pushing hard
in a certain direction, a heuristic may ultimately fail because it cannot escape local
minima. The Variable Fitness Function allows the fitness function to change over the
search and use objective measures not used in the fitness calculation. The Variable
Fitness Function and its ability to generalise are extensively tested in this thesis.
The two aims of the thesis are achieved and the methods are analysed in depth.
General conclusions and areas of future work are also identified.
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Kim, Dong-Gook. "An Analysis of Ecological and Social Rationality: When are Lexicographic Heuristics Preferred?" unrestricted, 2008. http://etd.gsu.edu/theses/available/etd-08182008-212550/.
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Thesis (Ph. D.)--Georgia State University, 2008.Title from file title page. Thomas Whalen, committee chair; Julian Diaz III, C. S. Thachenkary, Rodney Schultz, committee members. Electronic text (168 p. : ill. (some col.)) : digital, PDF file. Description based on contents viewed November 3, 2008. Includes bibliographical references (p. 164-168).
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Machac, Mary Kristin. "A Model of Expert Instructional Design Heuristics Incorporating Design Thinking Methods." Diss., Virginia Tech, 2021. http://hdl.handle.net/10919/102926.
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Novice instructional designers have limited experience working with ill-structured problems, and often do not possess the mental models to effectively analyze, manage, and communicate the overall design process of new instructional design projects (Wedman and Tessmer, 1993; Rowland, 1992; Perez and Emery, 1995; Liu, Gibby, Quiros, and Demps, 2002). In their 2016 article of expert instructional design principles applied by experienced designers in practice, York and Ertmer proposed the following questions for future research, "(a) Can we teach principles to novice instructional designers? (b) What methods should we use to provide this information?" (York and Ertmer, 2016, p. 189). This research further explored these questions and offers a new model of expert instructional design heuristics incorporating design thinking methods. The purpose of this study was to identify design thinking methods that aligned with heuristics of expert instructional design practitioners, and to design and develop a new model of heuristics and design thinking methods, which could assist novice instructional designers as they enter the instructional design field. The literature outlines challenges reported among novice instructional designers throughout the instructional design process, which includes their ability to solve ill-structured problems; conduct thorough analyses; collaborate in teams; negotiate priorities; generate a variety of ideas for solutions; overcome resource, budget and time constraints; communicate and manage projects with stakeholders; and prototype, iterate and pilot new design solutions (Rowland, 1992; Hoard, Stefaniak, Baaki, and Draper, 2019; Roytek, 2010; Liu, Gibby, Quiros, and Demps, 2002; Chang and Kuwata, 2020; Tracey and Boling, 2014; Perez and Emery, 1995; Williams van Rooij, 1993). The model offers novice instructional designers specific methods and combinations of methods to use for every stage of the instructional design process. As instructional designers implement design thinking methods within the context of their daily situations, they should become more comfortable and begin to adapt the methods to meet their individual needs for each stage of their process.Doctor of Philosophy
Instructional design is a system of procedures for developing education and training curricula in a consistent and reliable fashion (Branch and Merrill, 2011; Branch and Kopcha, 2014). It embodies an iterative process for outlining outcomes, selecting teaching and learning strategies, choosing support technologies, identifying media, and measuring performance (Branch and Kopcha, 2014). Instructional designers use models of instructional design and instructional development to communicate tasks and procedures of the instructional design process (Andrews and Goodson, 1980). Over the years, numerous models of instructional design have been developed and adapted to meet the varying needs of instructional designers and developers. There is a consensus that most instructional processes consist of five core elements or stages: analysis, design, development, implementation, and evaluation, which are commonly referred to as ADDIE (Seels and Glasgow, 1990; Branch and Kopcha, 2014). While often considered generic, the ADDIE framework contains a useful set of common criteria, which most designers state as important or necessary as a part of any instructional design process (Pittenger, Janke, and Bumgardner, 2009; York and Ertmer, 2011; 2016). Novice instructional designers have limited experience working with ill-structured problems, and often do not possess the mental models (prior experience) to effectively analyze, manage, and communicate the overall design process of new instructional design projects (Wedman and Tessmer, 1993; Rowland, 1992; Perez and Emery, 1995; Liu, Gibby, Quiros, and Demps, 2002). In their 2016 article of expert instructional design principles applied by experienced designers in practice, York and Ertmer proposed the following questions for future research, "(a) Can we teach principles to novice instructional designers? (b) What methods should we use to provide this information?" (York and Ertmer, 2016, p. 189). This research further explored these questions and offers a new model of expert instructional design heuristics incorporating design thinking methods. For this study, heuristics were defined as generalized stages of an instructional designer's process and design thinking was defined as a human-centered design process for solving complex problems. The purpose of this study was to identify design thinking methods that aligned with heuristics of expert instructional design practitioners, and to design and develop a new model of heuristics and design thinking methods, which could assist novice instructional designers as they enter the instructional design field. The literature outlines challenges reported among novice instructional designers throughout the instructional design process, which includes their ability to solve ill-structured problems; conduct thorough analyses; collaborate in teams; negotiate priorities; generate a variety of ideas for solutions; overcome resource, budget and time constraints; communicate and manage projects with stakeholders; and prototype, iterate and pilot new design solutions (Rowland, 1992; Hoard, Stefaniak, Baaki, and Draper, 2019; Roytek, 2010; Liu, Gibby, Quiros, and Demps, 2002; Chang and Kuwata, 2020; Tracey and Boling, 2014; Perez and Emery, 1995; Williams van Rooij, 1993). The model offers novice instructional designers specific methods and combinations of methods to use for every stage of the instructional design process. As instructional designers implement design thinking methods within the context of their daily situations, they should become more comfortable and begin to adapt the methods to meet their individual needs for each stage of their process.
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Ozdemir, Ersin. "Evolutionary methods for the design of digital electronic circuits and systems." Thesis, Cardiff University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326874.
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Sucu, Seda. "Solving crew scheduling problem in offshore supply vessels : heuristics and decomposition methods." Thesis, University of Strathclyde, 2017. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=29270.
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For the efficient utilisation of resources in various transportation settings, scheduling is a significant area of research. Having crew as the main resource for operation maintenance, scheduling crew have been a powerful decision making tool for optimisation studies. This research provides a detailed real case study analysis regarding the difficulties in planning crew in maritime industry. As a special case study, this thesis researches crew scheduling in offshore supply vessels which are used for specific operations of a global scaled company in oil and gas industry deeply with modified formulations, heuristics and decomposition methods. An extended version of computational study for a simple formulation approach (Task Based Model) is applied as deeper analysis to Leggate (2016). Afterwards, more realistic approach to the same problem is revised. Following the revision, a customized and thorough computational study on the heuristic method with various settings is designed and implemented in C++. After elaborated analysis completed on the suggested models firstly, a modification on Time Windows model is presented to increase the efficacy. This modification provides a sharp decrease in upper bounds within a short time compared to the previously suggested models. Through this suggestion, more economic schedules within a short period of time are generated. Achieving high performances from the modified model, an application of a decomposition algorithm is provided. We implemented a hybrid solution of Benders Decomposition with a customized heuristic for the modified model. Although this hybrid solution does not provide high quality solutions, it evaluates the performance of possible decomposed models with potential improvements for future research. An introduction to robust crew scheduling in maritime context is also given with a description of resources of uncertainty in this concept and initial robust formulations are suggested.
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Kwan, Alvin Chi Ming. "A framework for mapping constraint satisfaction problems to solution methods." Thesis, University of Essex, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339436.
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LITTON, JENNIFER GROMMON. "HEURISTIC DESIGN ALGORITHMS AND EVALUATION METHODS FOR PROPERTY MAPS." University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin981488752.
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Torrens, George. "An evaluation of the potential order and priority of research methods, design methods and design heuristics within an Assistive Technology new product development process." Thesis, Loughborough University, 2015. https://dspace.lboro.ac.uk/2134/18588.
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This commentary reflects on a series of published research articles, 1996-2013, that form a PhD thesis by publication. The articles offer evidence of research into best practice relating to Assistive Technology (AT) product design as a specialist section of Industrial Design (ID). The aim of the research has been to provide AT product developers with a methodology that ordered and prioritised the application of proven research methods, design methods and design heuristics; as well as, to highlight the fundamental concepts that underpin the methodology. This commentary provides a review of the methods applied and discussion of their efficacy within each case study. The series of articles, evaluated at a meta-analysis level in the second part of the commentary, address the following research questions: 1) What is the optimum order and priority of conventional design methods, heuristics and research methods when applied within a new product development process for assistive technology products?, 2) Through a meta-analysis of case studies, are there key aspects that underpin an optimum AT-ID process? From the review, 61 research methods, design methods and heuristics were defined. An order of methods and heuristics identified some methods that were used throughout all phases of a NPD process that included literature review, benchmarking, mixed methods and participatory research. The methods and heuristics used in all phases highlighted a user-centred approach and the close collaboration with end users and stakeholders. There was also a focus of methods and heuristics around phase 2 of the 5 design process phases defined by Martin and Hannington. The critical review also highlighted key underpinning aspects that helped optimise an Industrial Design approach to ID-AT NPD. These were 1) creating a format for dialogue within the constraints of perception and 2) previous experience and the application of ethically sound protocols for the whole process. Lastly the change of terminology and attitudes of those working the Assistive Technology industry highlighted the need for more research into social acceptance of all aspects of Assistive Technology and the perception of disability from those living with impairment and by UK society as a whole.
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Mohamed, Nurum Huda binti. "Hybridisation of heuristics and exact methods for the split delivery vehicle routing problem." Thesis, University of Kent, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.591103.
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Due to the worldwide of petrol prices crises that have been rising inevitably over the past years, any reduction in the transportation cost will benefit most companies. The purpose of this research is to contribute in solving this problem by alleviating some afthis burden. This thesis is about the Split Delivery Vehicle Routing Problem (SDVRP) and some of its variants. The SDVRP is a relaxed version of the classical VRP where customers can be visited more than once. It is also applicab le to problems with customers' demands larger than the vehicle capacity. These types of split routing problems can be found app licable in many real-world logistical problems. The total cost and the number of vehicles required could be reduced by allowing split deliveries. The savings are found to be the most in those problems with customers' demands nearly as large as the vehicle capacity limit. Some constructive heuristics adapted from the savings, the sweep and the insertion methods are first put forward to solve the SDVRP. These sets of solutions are then used in several set covering-based models which are proposed to so lve the problem. Both the heuristics and the set covering-based approaches are tested on two large sets of published data set from the literature with encouraging results. Similarly on the second data set, 12 best solutions are found from the 42 instances with an average deviation of 1.37%. As split deliveries may increase customers' administration cost and inconvenience, some models to cater for this drawback are proposed and their implementations are tested and evaluated against the classical SDVRP for guidance. This thesis is organised as follows: In the first chapter, a brief overview of logistics and distribution management, in particular with respect to vehicle routing, is provided. A brief explanation about the TSP, the VRP and its variants is also presented. Methodologies for solving these kinds of problems are also given. This is then followed by an example to illustrate the benefit of sp lit deliveries in Chapter 2 together with the SDVRP mathematical formulations and a review of the methods used to tackle the SDVRP and its variants. A brief introduction to the two benchmark SDVRP data sets used is given at the end of this chapter. Several constructive heuristics are first implemented in the third chapter. These are adapted from the Savings, the Sweep and the Insertion methods to include split deliveries. These methods are coded in C++ Language and tested on the two SDVRP data sets taken from the literature and their performance is evaluated against the best published resu lts showing encouraging results. In Chapter 4, an existing mathematical programming approach based on the set covering is implemented using ILOO CPLEX Callable Library. This approach uses several sets of routes from the obtained solutions by the constructive heuristics in Chapter 3. New mathematical ILP based models are adapted and a pi lot test is conducted within a limited time to select the most appropriate model and corresponding CPLEX parameters. New best results are discovered by the selected model on the two large data sets. In Chapter 5, the dual information relating to both customers and routes, is obtained by relaxing the selected set covering-based problem as a Linear Programming. The customers' dual information is incorporated in both the classical insertion cost formula and the well-known savings formulae and is proved to be beneficial. Route reduction schemes are then designed to inc lude those promising routes only. At the end of this chapter, a new set of routes is then constructed by combining the new generated routes and those subsets of routes found previously. This set is then used in the selected model where some new best results are obtained. A new variant of the SDVRP is introduced in Chapter 6 where an incentive scheme is incorporated to overcome the inconvenience of those affected customers that have split deliveries. Two new models are then explored and adapted from the previous set covering-based models. Given that no published results exist for these variants, as a guide, those results originated from the classical SDVRP are used for comparison purpose. Our find ings and suggestions for potential future research are highlighted in the final chapter.
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Somervell, Jacob Paul. "Developing Heuristic Evaluation Methods for Large Screen Information Exhibits Based on Critical Parameters." Diss., Virginia Tech, 2004. http://hdl.handle.net/10919/11206.
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Evaluation is the key to effective interface design. It becomes even more important when the interfaces are for cutting edge technology, in application areas that are new and with little prior design knowledge. Knowing how to evaluate new interfaces can decrease development effort and increase the returns on resources spent on formative evaluation. The problem is that there are few, if any, readily available evaluation tools for these new interfaces.
This work focuses on the creation and testing of a new set of heuristics that are tailored to the large screen information exhibit (LSIE) system class. This new set is created through a structured process that relies upon critical parameters associated with the notification systems design space. By inspecting example systems, performing claims analysis, categorizing claims, extracting design knowledge, and finally synthesizing heuristics; we have created a usable set of heuristics that is better equipped for supporting formative evaluation.
Contributions of this work include: a structured heuristic creation process based on critical parameters, a new set of heuristics tailored to the LSIE system class, reusable design knowledge in the form of claims and high level design issues, and a new usability evaluation method comparison test. These contributions result from the creation of the heuristics and two studies that illustrate the usability and utility of the new heuristics.Ph. D.
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Mundim, Leandro Resende. "Mathematical models and heuristic methods for nesting problems." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/55/55134/tde-08122017-143216/.
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Irregular cutting and packing problems, with convex and non-convex polygons, are found in many industries such as metal mechanics, textiles, of shoe making, the furniture making and others. In this thesis we study the two-dimensional version of these problems, where we want to allocate a set of items, without overlap, inside one or more containers, limited or unlimited, so as to optimize an objective function. In this document we study the knapsack problem, placement problem, strip packing problem, cutting stock problem and bin packing problem. For these problems, the heuristic methods and mathematical programming models are proposed and presented very promising results, surpassing in many cases the best results in the specialized literature. This thesis is organized as follows. In Chapter 1, we present a review of the studied problems, the value proposition for this thesis with the main contributions and ideas. In Chapter 2, we propose a metaheursitic for the strip packing problem with irregular items and circles. Then, in Chapter 3, we present a generic heuristic for the allocation of irregular items that may be weakly or strongly heterogeneous and will be allocated in a container (output maximization problems) or multiple containers (input minimization problems). In Chapter 4, we propose a solution method for the cutting stock problem with deterministic demand and stochastic demand. In Chapters 5 and 6, we present mathematical programming models for the strip packing problem. Finally, in Chapter 7, we present a conclusion and a concise direction for future works.Os problemas de corte e empacotamento de itens irregulares, polígonos convexos e não convexos, são encontrado em diversas indústrias, tais como a metal-mecânica, a têxtil, a de calçados, a moveleira e outras. Nesta tese estudamos a versão bidimensional destes problemas, na qual desejamos alocar um conjunto de itens, sem sobreposição, no interior de um ou mais recipientes, limitados ou ilimitados, de modo a otimizar uma função objetivo. Neste trabalho estudamos o problema da mochila, o problema do assentamento, o problema empacotamento em faixa, o problema de corte de estoque e o problema de empacotamento de contêineres. Para estes problemas, os métodos heurísticos e modelos de programação matemática propostos e apresentam resultados muito promissores, ultrapassando em muitos casos os melhores resultados da literatura especializada. Esta tese esta organizada da seguinte maneira. No Capítulo 1, apresentamos uma revisão dos problemas estudados, a proposta de valor deste doutorado com as principais contribuições e ideias. No Capítulo 2, propomos uma meta-heurística para o problema de empacotamento em faixa para itens irregulares e círculos. Em seguida, no Capítulo 3 apresentamos uma heurística genérica para a alocação de itens irregulares que podem ser fracamente ou fortemente heterogêneos e serão alocados em um recipiente (problema de maximização de saída) ou de múltiplos recipientes (problemas de minimização de entrada). O Capítulo 4 propõem um método de solução para o problema de corte de estoque com demanda conhecida e demanda estocástica. Nos Capítulos 5 e 6 apresentamos modelos de programação matemática para o problema de corte de itens irregulares em faixa. Finalmente, no Capítulo 7, apresentamos a conclusão e uma sucinta direção para os trabalhos futuros.
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McMeen, John Norman Jr. "Ranking Methods for Global Optimization of Molecular Structures." Digital Commons @ East Tennessee State University, 2014. https://dc.etsu.edu/etd/2447.
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This work presents heuristics for searching large sets of molecular structures for low-energy, stable systems. The goal is to find the globally optimal structures in less time or by consuming less computational resources. The strategies intermittently evaluate and rank structures during molecular dynamics optimizations, culling possible weaker solutions from evaluations earlier, leaving better solutions to receive more simulation time. Although some imprecision was introduced from not allowing all structures to fully optimize before ranking, the strategies identify metrics that can be used to make these searches more efficient when computational resources are limited.
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Boke, Cem. "Combining and analyzing the tanker and aircrew scheduling heuristics." View thesis, 2003. http://handle.dtic.mil/100.2/ADA412689.
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Thesis (M.S.)--Air Force Institute of Technology, 2003.Title from title screen (viewed Oct. 28, 2003). "March 2003." Vita. "AFIT/GOR/ENS/03-04." Includes bibliographical references (leaves 69-70). Also issued in paper format.
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Demircan, Ahmet Emrah. "Routing Optimization Methods For Communication Networks." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605908/index.pdf.
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This study discusses the routing optimization techniques and algorithms for communication networks. Preventing data loss on overloaded communication links and utilizing link bandwidths efficiently are the main problems of traffic engineering. Load balancing and routing problems are solved using both by heuristics such as genetic algorithms, and simulation techniques. These algorithms work on destination-based or flow-based routing techniques and mainly change the link weight system or try to select the best routes set upon K-routes routing table respectively to optimize network utilization. In this study, first a definition of the network routing optimization problem will be made. Then the heuristics to solve the problem will be discussed and finally an analysis of these heuristics will be made on sample network models. This thesis includes a discussion about the performance of different optimization heuristics working as a part of the centralized network load balancing systems.
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Hassan, Abdeljabbar Hassan Mohammed Albarra. "Parallel Scheduling in the Cloud Systems : Approximate and Exact Methods." Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0223/document.
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Cette thèse porte sur la résolution exacte et heuristique de plusieurs problèmes ayant des applications dans le domaine de l'Informatique dématérialisé (cloud computing). L'Informatique dématérialisée est un domaine en plein extension qui consiste à mutualiser les machines/serveurs en définissant des machines virtuelles représentant des fractions des machines/serveurs. Il est nécessaire d'apporter des solutions algorithmiques performantes en termes de temps de calcul et de qualité des solutions. Dans cette thèse, nous nous sommes intéressés dans un premier temps au problème d'ordonnancement sur plusieurs machines (les machines virtuelles) avec contraintes de précédence, c.-à-d., que certaines tâches ne peuvent s'exécuter que si d'autres sont déjà finies. Ces contraintes représentent une subdivision des tâches en sous tâches pouvant s'exécuter sur plusieurs machines virtuelles. Nous avons proposé plusieurs algorithmes génétiques permettant de trouver rapidement une bonne solution réalisable. Nous les avons comparés avec les meilleurs algorithmes génétiques de la littérature et avons défini les types d'instances où les solutions trouvées sont meilleures avec notre algorithme. Dans un deuxième temps, nous avons modélisé ce problème à l'aide de la programmation linéaire en nombres entiers permettant de résoudre à l'optimum les plus petites instances. Nous avons proposé de nouvelles inégalités valides permettant d'améliorer les performances de notre modèle. Nous avons aussi comparé cette modélisation avec plusieurs formulations trouvées dans la littérature. Dans un troisième temps, nous avons analysé de manière approfondie la sous-structure du sous-graphe d'intervalle ne possédant pas de clique de taille donnée. Nous avons étudié le polytope associé à cette sous-structure et nous avons montré que les facettes que nous avons trouvées sont valides pour le problème d'ordonnancement sur plusieurs machines avec contraintes de précédence mais elles le sont aussi pour tout problème d'ordonnancement sur plusieurs machines. Nous avons étendu la modélisation permettant de résoudre le précédent problème afin de résoudre le problème d'ordonnancement sur plusieurs machines avec des contraintes disjonctives entre les tâches, c.-à-d., que certaines tâches ne peuvent s'exécuter en même temps que d'autres. Ces contraintes représentent le partage de ressources critiques ne pouvant pas être utilisées par plusieurs tâches. Nous avons proposé des algorithmes de séparation afin d'insérer de manière dynamique nos facettes dans la résolution du problème puis avons développé un algorithme de type Branch-and-Cut. Nous avons analysé les résultats obtenus afin de déterminer les inégalités les plus intéressantes afin de résoudre ce problème. Enfin dans le dernier chapitre, nous nous sommes intéressés au problème d'ordonnancement d'atelier généralisé ainsi que la version plus classique d'ordonnancement d'atelier (open shop). En effet, le problème d'ordonnancement d'atelier généralisé est aussi un cas particulier du problème d'ordonnancement sur plusieurs machines avec des contraintes disjonctives entre les tâches. Nous avons proposé une formulation à l'aide de la programmation mathématique pour résoudre ces deux problèmes et nous avons proposé plusieurs familles d'inégalités valides permettant d'améliorer les performances de notre algorithme. Nous avons aussi pu utiliser les contraintes définies précédemment afin d'améliorer les performances pour le problème d'ordonnancement d'atelier généralisé. Nous avons fini par tester notre modèle amélioré sur les instances classiques de la littérature pour le problème d'ordonnancement d'atelier. Nous obtenons de bons résultats permettant d'être plus rapide sur certaines instancesThe Cloud Computing appears as a strong concept to share costs and resources related to the use of end-users. As a consequence, several related models exist and are widely used (IaaS, PaaS, SaaS. . .). In this context, our research focused on the design of new methodologies and algorithms to optimize performances using the scheduling and combinatorial theories. We were interested in the performance optimization of a Cloud Computing environment where the resources are heterogeneous (operators, machines, processors...) but limited. Several scheduling problems have been addressed in this thesis. Our objective was to build advanced algorithms by taking into account all these additional specificities of such an environment and by ensuring the performance of solutions. Generally, the scheduling function consists in organizing activities in a specific system imposing some rules to respect. The scheduling problems are essential in the management of projects, but also for a wide set of real systems (telecommunication, computer science, transportation, production...). More generally, solving a scheduling problem can be reduced to the organization and the synchronization of a set of activities (jobs or tasks) by exploiting the available capacities (resources). This execution has to respect different technical rules (constraints) and to provide the maximum of effectiveness (according to a set of criteria). Most of these problems belong to the NP-Hard problems class for which the majority of computer scientists do not expect the existence of a polynomial exact algorithm unless P=NP. Thus, the study of these problems is particularly interesting at the scientific level in addition to their high practical relevance. In particular, we aimed to build new efficient combinatorial methods for solving parallel-machine scheduling problems where resources have different speeds and tasks are linked by precedence constraints. In our work we studied two methodological approaches to solve the problem under the consideration : exact and meta-heuristic methods. We studied three scheduling problems, where the problem of task scheduling in cloud environment can be generalized as unrelated parallel machines, and open shop scheduling problem with different constraints. For solving the problem of unrelated parallel machines with precedence constraints, we proposed a novel genetic-based task scheduling algorithms in order to minimize maximum completion time (makespan). These algorithms combined the genetic algorithm approach with different techniques and batching rules such as list scheduling (LS) and earliest completion time (ECT). We reviewed, evaluated and compared the proposed algorithms against one of the well-known genetic algorithms available in the literature, which has been proposed for the task scheduling problem on heterogeneous computing systems. Moreover, this comparison has been extended to an existing greedy search method, and to an exact formulation based on basic integer linear programming. The proposed genetic algorithms show a good performance dominating the evaluated methods in terms of problems' sizes and time complexity for large benchmark sets of instances. We also extended three existing mathematical formulations to derive an exact solution for this problem. These mathematical formulations were validated and compared to each other by extensive computational experiments. Moreover, we proposed an integer linear programming formulations for solving unrelated parallel machine scheduling with precedence/disjunctive constraints, this model based on the intervaland m-clique free graphs with an exponential number of constraints. We developed a Branch-and-Cut algorithm, where the separation problems are based on graph algorithms. [...]
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Lindell, Hugo. "Methods for optimizing large scale thermal imaging camera placement problems." Thesis, Linköpings universitet, Optimeringslära, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-161946.
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The objective of this thesis is to model and solve the problem of placing thermal imaging camera for monitoring piles of combustible bio-fuels. The cameras, of different models, can be mounted at discrete heights on poles at fixed positions and at discrete angles, and one seeks camera model and mounting combinations that monitor as much of the piles as possible to as low cost as possible. Since monitoring all piles may not be possible or desired, due to budget or customer constrains, the solution to the problem is a set of compromises between coverage and cost. We denote such a set of compromises a frontier. In the first part of the thesis a way of modelling the problem is presented. The model uses a discrete formulation where the area to monitor is partitioned into a grid of cells. Further, a pool of candidate camera placements is formed, containing all combinations of camera models and mounting positions. For each camera in this pool, all cells monitored are deduced using ray-casting. Finally, an optimization model is formulated, based on the pool of candidate cameras and their monitoring of the grid. The optimization model has the two objectives of minimizing the cost while maximizing the number of covered cells. In the second part, a number of heuristic optimization algorithms to solve the problem is presented: Greedy Search, Random Greedy Search, Fear Search, Unique Search, Meta-RaPS and Weighted Linear Neighbourhood Search. The performance of these heuristics is evaluated on a couple of test cases from existing real world depots and a few artificial test instances. Evaluation is made by comparing the solution frontiers using various result metrics and graphs. Whenever practically possible, frontiers containing all optimal cost and coverage combinations are calculated using a state-of-the-art solver. Our findings indicate that for the artificial test instances, the state-of-the-art solver is unmatched in solution quality and uses similar execution time as the heuristics. Among the heuristics, Fear Search and Greedy Search were the strongest performing. For the smaller real world instances, the state-of-the-art solver was still unmatched in terms of solution quality, but generating the frontiers in this way was fairly time consuming. By generating the frontiers using Greedy Search or Random Greedy Search we obtained solutions of similar quality as the state-of-the-art solver up to 70-80% coverage using one hundredth and one tenth of the time, respectively. For the larger real world problem instances, generating the frontier using the state-of-the-art solver was extremely time consuming and thus sometimes impracticable. Hence the use of heuristics is often necessary. As for the smaller instances, Greedy Search and Random Greedy Search generated the frontiers with the best quality. Often even better full coverage solutions could be found by the more time consuming Fear Search or Unique Search.Syftet med detta examensarbete är att modellera och lösa kameraplaceringsproblemet då IR-kameror ska användas för brandövervakning av fastbränslehögar. Problemet består i att givet ett antal kamera modeller och monteringsstolpar bestämma de kombinationer av placeringar och modeller sådana att övervakningen av högarna är maximal, för alla möjliga kostnadsnivåer. I den första delen av examensarbetet presenteras en modell för detta kameraplaceringsproblem. Modellen använder sig av en diskret formulering, där området om ska övervaras är representerad av ett rutnät. De möjliga kameravalen beskrivas med en diskret mängd av möjliga kameraplaceringar. För att utröna vilka celler inom rutnätet som en kameraplacering övervakar används metoden ray-casting. Utifrån mängden av möjliga kameraplaceringar kan en optimeringsmodell med två målfunktioner formuleras. Målet i den första målfunktionen är att minimera kostnaden för övervakningen och i den andra att maximera storleken på det övervakade området. Utgående från denna modell presenteras därefter ett antal algoritmer för att lösa modellen. Dessa är: Greedy Search, Random Greedy Search, Fear Search, Unique Search, Meta-RaPS och Weighted Linear Neighbourhood Search. Algoritmerna utvärderas på två konstgjorda testproblem och ett antal problem från verkliga fastbränslelager. Utvärderingen baseras på lösningsfronter (grafer över de icke-dominerade lösningarna med de bästa kombinationerna av kostnad och täckning) samt ett antal resultatmått som tid, lägsta kostnad för lösning med full täckning, etc... Vid utvärderingen av resultaten framkom att för de konstgjorda testinstanserna presterade ingen av heuristikerna jämförbart med en standardlösare, varken i termer av kvalitén på lösningarna eller med hänsyn tagen till tidsåtgången. De heuristiker som presterade bäst på dessa problem var framförallt Fear Search och Greedy Search. Även på de mindre probleminstanserna från existerande fastbränslelager hittade standardlösaren optimala lösningsfronter och en lösning med full täckning, men tidsåtgången var här flera gånger större jämfört med vissa av heuristikerna. På en hundra- respektive en tiondel av tiden kan Greedy Search eller Random Greedy Search heuristikerna finna en lösningsfront som är jämförbar med standardlösare, upp till 70-80% täckning. För de största probleminstanserna är tidsåtgången vid användning av standardlösare så pass stor att det i många fall är praktiskt svårt att lösa problemen, både för att generera fronten och att hitta en lösning med full täckning. I dessa fall är heuristiker oftast de enda möjliga alternativen. Vi fann att Greedy Search och Random Greedy Search var de heuristiker som, liksom för de mindre probleminstanserna, genererade de bästa lösningsfronterna. Ofta kunde dock en bättre lösning för full täckning hittas med hjälp av Fear Search eller Unique Search.
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Enoch, John. "Application of Decision Analytic Methods to Cloud Adoption Decisions." Thesis, Högskolan i Gävle, Avdelningen för Industriell utveckling, IT och Samhällsbyggnad, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-25560.
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This thesis gives an example of how decision analytic methods can be applied to choices in the adoption of cloud computing. The lifecycle of IT systems from planning to retirement is rapidly changing. Making a technology decision that can be justified and explained in terms of outcomes and benefits can be increasingly challenging without a systematic approach underlying the decision making process. It is proposed that better, more informed cloud adoption decisions would be taken if organisations used a structured approach to frame the problem to be solved and then applied trade-offs using an additive utility model. The trade-offs that can be made in the context of cloud adoption decisions are typically complex and rarely intuitively obvious. A structured approach is beneficial in that it enables decision makers to define and seek outcomes that deliver optimum benefits, aligned with their risk profile. The case study demonstrated that proven decision tools are helpful to decision makers faced with a complex cloud adoption decision but are likely to be more suited to the more intractable decision situations.
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Farias, de Araújo Katyanne. "Inventory routing problems on two-echelon systems : exact and heuristic methods for the tactical and operational problems." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAI064.
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Les activités de transport et de gestion des stocks ont un impact important les unes sur les autres. Assurer un niveau de stock idéal peut demander des livraisons fréquentes, ce qui entraîne des coûts logistiques élevés. Pour optimiser les compromis entre les coûts de stock et de transport, des systèmes VMI (Vendor Managed Inventory) ont été développés pour gérer ensemble les opérations de stock et de transport. Pour un ensemble de clients ayant des demandes sur un horizon de temps, le problème de détermination des tournées et des quantités à livrer avec un coût minimum de gestion de stock et de transport est connu sous le nom de Inventory Routing Problem (IRP). Les systèmes à deux échelons ont également été étudiés pour améliorer le flux de véhicules dans les zones urbaines. étant donné que des nouvelles politiques de gestion sont apparues, dans le but de limiter le trafic des gros véhicules et leur vitesse dans les centres urbains, des Centres de Distribution (DC) sont mis en place pour coordonner les flux de marchandises à l'intérieur et à l'extérieur des zones urbaines. Les produits sont donc livrés aux clients par les fournisseurs via les DC.Nous proposons de combiner un système à deux échelons avec le IRP. Nous introduisons un Operational Two-Echelon Inventory Routing Problem (O-2E-IRP), ce qui est une nouvelle extension du IRP à notre connaissance. Dans le O-2E-IRP proposé, les clients doivent être servis par un fournisseur strictement via des DC et les tournées doivent être définis dans les deux échelons sur un horizon de temps donné. Trois politiques de réapprovisionnement et de configurations de routage différentes sont modélisées pour ce problème. Nous développons deux formulations mathématiques, ainsi qu'un algorithme Branch-and-Cut (B&C) combiné à une matheuristique pour résoudre le problème. De plus, nous analysons plusieurs inégalités valides disponibles pour le IRP et nous introduisons de nouvelles inégalités valides inhérentes au IRP à deux échelons. Des expériences de calcul approfondies ont été effectuées sur un ensemble d'instances générées de manière aléatoire. Les résultats obtenus montrent que les performances des méthodes sont liées à la politique de stock et à la configuration de routage.Dans le contexte d'un IRP à deux échelons, deux décisions tactiques importantes doivent être prises en plus des décisions de livraison de routage et de quantité de livraison: à partir de quel DC sera fourni chaque client et en utilisant quels véhicules ? Répondre à ces questions est extrêmement difficile car cela implique de pouvoir minimiser les coûts opérationnels d'un système de livraison VMI à deux échelons à long-terme et avec des demandes incertaines. Pour faire face à cela, nous présentons le Tactical Two-Echelon Inventory Routing Problem (T-2E-IRP) qui optimise les décisions en fonction d'un horizon à long-terme et en tenant compte des demandes stochastiques. Trois politiques de gestion des stocks sont modélisées et appliquées à un ou aux deux échelons. Nous développons une approche de simulation pour résoudre le T-2E-IRP sur un horizon de temps à long-terme. Nous proposons quatre formulations et deux algorithmes B&C pour définir l'affectation des clients et des véhicules aux DC en fonction d'un horizon de temps court. Ensuite, nous évaluons ces décisions d'affectation via un outil de simulation qui résout un sous-problème du T-2E-IRP, qui consiste en les décisions de livraisons du fournisseur aux DC et des DC aux clients, sur un horizon glissant. De nombreuses expériences sont effectuées pour un ensemble d'instances générées aléatoirement. L'impact de plusieurs paramètres utilisés pour déterminer l'affectation des clients et des véhicules aux DC sur le coût total est analysé. Basé sur des expériences, nous définissons la combinaison de paramètres qui fournit généralement les meilleurs résultats sur les instances généréesTransport and inventory management activities have a great impact on each other. Ensuring an ideal inventory level can require frequent deliveries, leading to high logistics costs. To optimize the trade-offs between inventory and transportation costs, VMI (Vendor Managed Inventory) systems have been developed to manage inventory and transportation operations together. Given a set of customers with demands over a time horizon, the problem of determining routes and delivery quantities at a minimum inventory holding and transportation costs is known as Inventory Routing Problem (IRP). Two-echelon systems have also been studied to improve the freight vehicle flow inside urban areas. As new management policies have emerged, with the goal of limiting the traffic of large vehicles and their speed in urban centers, Distribution Centers (DC) are introduced to coordinate freight flows inside and outside the urban areas. Products are then delivered from the suppliers to the customers through the DC.We propose to combine a two-echelon system with the IRP. We introduce an Operational Two-Echelon Inventory Routing Problem (O-2E-IRP), which is a new extension of the IRP to the best of our knowledge. On the proposed O-2E-IRP, the customers must be served by a supplier strictly through DC and routes must be defined in both echelons over a given time horizon. Three different replenishment policies and routing configurations are modeled for this problem. We develop two mathematical formulations, and a Branch-and-Cut (B&C) algorithm combined with a matheuristic to solve the problem. In addition, we analyze several valid inequalities available for IRP, and we introduce new ones inherent to the IRP within two echelons. Extensive computational experiments have been carried out on a set of randomly generated instances. The obtained results show that the performance of the methods is related to the inventory policy and routing configuration.In the context of a two-echelon IRP, two important tactical decisions have to be taken in addition to route and quantity delivery decisions: from which DC will be supplied each customer and using which vehicles? Answering these questions is extremely difficult as it implies being able to minimize operational costs for a two-echelon VMI delivery system on long-term and with uncertain demands. In order to deal with this, we introduce the Tactical Two-Echelon Inventory Routing Problem (T-2E-IRP) that optimizes the decisions based on a long-term horizon and considering stochastic demands. Three inventory management policies are modeled and applied at one or both echelons. We develop a simulation approach to solve the T-2E-IRP on a long-term time horizon. We propose four formulations and two B&C algorithms to define the assignment of customers and vehicles to the DC based on a short time horizon. Then, we evaluate these assignment decisions through a simulation tool that solves a subproblem of the T-2E-IRP, which consists of the decisions of deliveries from the supplier to the DC and from the DC to the customers, on a rolling-horizon framework. Extensive computational experiments are performed for a set of randomly generated instances. The impact of several parameters used to determine the assignment of customers and vehicles to DC on the total cost is analyzed. Based on the experiments, we define the combination of parameters that generally provides the best results on the generated instances
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Hewitt, Michael R. "Integer programming based search." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31641.
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Thesis (Ph.D)--Industrial and Systems Engineering, Georgia Institute of Technology, 2010.Committee Chair: Erera, Martin; Committee Chair: Nemhauser, George; Committee Chair: Savelsbergh, Martin; Committee Member: Ergun, Ozlem; Committee Member: Ferguson, Mark. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Furlan, Marcos Mansano. "Métodos heurísticos para o problema de dimensionamento de lotes multiestágio com limitação de capacidade." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/55/55134/tde-16052011-162401/.
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O problema de dimensionamento de lotes determina um plano de produção que apoia às tomadas de decisões, a médio prazo, em meios industriais. Este plano de produção indica as quantidades de cada item que devem ser produzidas em cada período do horizonte de planejamento, de acordo com um objetivo dado e satisfazendo a demanda dos clientes. Diversos métodos de solução foram propostas na literatura, considerando a dificuldade de solução de algumas classes de problemas e a necessidade de métodos que gerem soluções de alta qualidade em um tempo computacional adequado. Neste trabalho, abordamos heurísticas baseadas na formulação matemática (LP-and-fix, relax-and-fix e fix-and-optimize), uma metaheurística (algoritmo de abelhas) e dois métodos híbridos, utilizados na solução de dois problemas distintos de dimensionamento de lotes multiestá- gio com limitação de capacidade. Consideramos também, a utilização de três formulações da literatura, para verificar a influência de cada uma sobre as abordagens de solução verificadas. Os resultados computacionais demonstraram que os métodos baseados na formulação matemática do problema se mostraram eficientes, mas limitados normalmente a ótimos locais, enquanto os métodos híbridos puderam superar estes ótimos locais, utilizando conceitos da metaheurística algoritmo de abelhas para isto. Além disso, pudemos verificar a influência de uma formulação \"forte\" sobre as soluções geradas pelas abordagens de solução, demonstrando que métodos baseados em relaxação linear conseguem obter maiores vantagens deste tipo de formulação, mas outras abordagens podem ou não obter estas vantagens, dependendo do problema abordadoThe lot-sizing problem determines a production plan, which supports the decision making, in the medium term, at the industrial environment. This production plan indicates the amounts of each item to be produced in each period of the planning horizon, according to a given objective and satisfying customer\'s demand. Diverse solution methods have been proposed in the literature, considering the difficulty of solving some problem classes and the need of methods to generate solutions quickly. In this work, we develop matheuristics (LP-and-fix, relax-and-fix and fix-and-optimize), one metaheuristic (bees algorithm) and two hybrid methods, used to solve two different multilevel capacitated lot-sizing problems. We also consider the use of three different formulations of the literature to verify the influence of each one on the solutions approaches. The computational results show that the matheuristics proved to be efficient, but usually limited to local optima, while the hybrid methods could escape from these local optima, using concepts of bees algorithm to do this. Additionally, we test the effect of a tight formulation on the solutions approaches, demonstrating that LP-based heuristics can obtain further advantages from this type of formulation, but other approaches can take these advantages, depending on the problem addressed
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Munisamy, Kolandai Ammu Prabha. "A Method for Evaluating the Persuasive Potential of Software Programs." Thesis, Linköpings universitet, Interaktiva och kognitiva system, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-98002.
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Today, web, Internet, mobile and other ambient technologies engage in persuasive interaction with people. The technology designed to reinforce and change user’s attitude or behaviors or both through persuasion and social influence are persuasive technologies. Recently, persuasive systems and services are becoming increasingly abundant and ubiquitous. Evaluation of these systems is a challenging endeavor and typically requires a simple and efficient method. Nielsen suggests heuristic evaluation as a method for intuitive, inexpensive and easy evaluation of a user interface design. The purpose of this thesis is to examine heuristic evaluation as a method to evaluate the persuasive potential of software programs. The Heuristics used were operationalized version of Fogg’s persuasive design principles. Software programs MS Word, MS PowerPoint, Counter-Strike, The Sims, Stone and Plan Eat Smile were chosen with the goal of measuring their ability to change behavior or attitude of users. The Evaluation was performed on the software programs using three evaluators and the test results indicated that they possess significant persuasive potential. It was concluded that the set of heuristics which were developed can be used to perform summative heuristic evaluation and the method used was helpful in evaluating the persuasive potential of software programs.
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Söderberg, Christian. "Heuristisk utvärdering av typografi i responsiva gränssnitt." Thesis, Linköpings universitet, Interaktiva och kognitiva system, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-119737.
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Denna studie syftar till att utveckla tumregler för heuristisk utvärdering av typografi i responsiva gränssnitt. Genom att kombinera traditionella typografiska designprinciper med principer för responsiv webbdesign har tolv tumregler tagits fram. Dessa tumregler har i två heuristiska utvärderingar använts av grafiska designers och gränssnittsutvecklare. De båda grupperna har dessutom fått ge sin syn på upplevelsen av att använda tumreglerna. Tumreglernas förmåga att vägleda till hittade typografiska problem i två responsiva gränssnitt har analyserats och framförallt gränssnittsutvecklarnas resultat har varit i fokus, då målet varit att tumreglerna ska kunna fungera som ett verktyg för att skapa bättre design för gränssnittsutvecklare utan utbildning i ämnet. Resultatet har visat att trots att gränssnittsutvecklare inte hittade lika många problem som grafiska designers så hjälper tumreglerna ändå till att hitta problem. Detta indikerar att fler deltagare utan typografisk utbildning kan behövas för att komma upp i samma mängd hittade problem som en grupp med typografiskt utbildade deltagare. Resultatet visar också att utvärderingar av responsiva gränssnitt görs bäst genom att granska gränssnittet på flera enheter med varierande skärmstorlek.This study aims to develop a set of heuristics for evaluating typography in responsive user interfaces. By combining traditional design principles for typography with principles for responsive web design, twelve heuristics has been created. This list of heuristics has been used by graphic designers and user interface developers in two heuristic evaluations. The heuristics ability to lead to finding typographic problems in two different responsive interfaces has been analyzed, and the results from the user interface developers has been in main focus, since the goal was to create a tool for developers with a lack of knowledge in typography to create interfaces with better design. The results has shown that even though developers struggle to find the samt amount of typography problems as graphic designers, the heuristics does help to find problem. Even so, this indicate that a heuristic evaluation with non-typographic experts may need a few more participants than an evaluation with only typographic experts. The results also shows that an evaluation of a responsive user interface is best made through evaluation of the same interface on different devices with different screen sizes.
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Jochumsson, Thorvaldur. "Heuristic multi-sequence search methods." Thesis, University of Skövde, Department of Computer Science, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-530.
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With increasing size of sequence databases heuristic search approaches have become necessary. Hidden Markov models are the best performing search methods known today with respect to discriminative power, but are too time complex to be practical when searching in large sequence databases. In this report, heuristic algorithms that reduce the search space before searching with traditional search algorithms of hidden Markov models are presented and experimentally validated. The results of the validation show that the heuristic search algorithms will speed up the searches without decreasing their discriminative power.
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Rodrigues, Infância da Assunção. "Determinação de rotas de distribuição e recolha de produtos." Master's thesis, Instituto Superior de Economia e Gestão, 2014. http://hdl.handle.net/10400.5/8494.
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Mestrado em Decisão Económica e EmpresarialEste trabalho final de mestrado trata o Problema de Identificação de Rotas de Veículos com Recolha e Entrega em Simultâneo (Vehicle Routing Problem with Simultaneous Pickup and Delivery ? VRPSPD). O ponto crítico do problema assenta no facto de ambas as atividades, recolha e entrega, serem realizadas em simultâneo. Desta forma, a carga do veículo deve ser controlada após cada passagem por um cliente de modo a garantir que a capacidade do veículo não é excedida. O Problema de Identificação de Rotas com Recolha e Entrega em Simultâneo lida com um único depósito de distribuição, servindo um conjunto de clientes. Cada cliente requer dois tipos de serviço: a recolha e a entrega. Os produtos a entregar são carregados no depósito e os produtos a recolher são transportados para o depósito. Cada cliente é servido por um único veículo. Neste trabalho foram usados os modelos matemáticos de (Dethloff, 2001) e de (Montané & Galvão, 2006), para resolver o problema em questão, utilizando o software Frontline Solver. Os dois modelos são comparados quanto ao número de variáveis, e de restrições e sendo ilustrados os resultados obtidos num exemplo.
This work deals with the Vehicle Routing Problem with Simultaneous Pickup and Delivery (VRPSPD). The critical aspect of the problem lies in the fact that both activities, delivery and pickup, are performed simultaneously. Thus, the load of the vehicle should be controlled after each costumer service to ensure that capacity of the vehicle is not exceeded. The VRSPD deals with a single distribution warehouse serving a set of customers. Each customer requires two types of service: the pickup and the delivery. The products to delivery are loaded at the warehouse and the products to pickup are transported to the warehouse. Each client is served by a single vehicle. In this work two mathematical models (Dethloff, 2001) and (Montané & Galvão, 2006) are used, to solve the problem at hand, through the software Solver Frontline. The two models are compared regarding the number of variables, and constraints, and the results on an example.
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Lewis, John N. "Expert systems development utilizing heuristic methods." Thesis, Monterey, California. Naval Postgraduate School, 1996. http://hdl.handle.net/10945/8376.
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Approved for public release; distribution is unlimited.This thesis analyzes the diagnostic domain and isolates the heuristics employed by experts to arrive at diagnostic solutions. These heuristic methods are then generalized in order to arrive at a series of heuristic rules that can be applied to a wide range of diagnostic processes independent of there respective domain. To test the validity of the generalized heuristics, a prototype expert system was created targeting the heuristics employed by avionics repair technicians in repair of the APS- 1 15 radar system on the P-3C Orion.
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Gőtz, Ondřej. "Využití metody výhodnostních čísel v úlohách kurýrní služby." Master's thesis, Vysoká škola ekonomická v Praze, 2014. http://www.nusl.cz/ntk/nusl-193489.
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The diploma thesis deals with the use of heuristic methods for solving messenger problems. The first part focuses on the proposed vehicle routing problems, especially on travelling salesman problems and the messenger problems. For individual problems are theoretically discussed mathematical models for variants with one or more vehicles and the expansion of the use of time windows and capacity constraints. The second part introduces heuristic algorithms for the method of nearest neighbour, savings method, insertion method and the exchange method on the travelling salesman problems. Then all of the mentioned algorithms are modified for use in three variants of messenger problem. First, the disposition of one vehicle, the second allows more messengers in the same starting point and the last option is more messengers at different starting points. The last part describes computational experiments and comparison of results provided by different methods. The diploma thesis includes application for solving messenger problems using savings methods programmed in Visual Basic for Application in MS Excel.
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Bartásková, Petra. "Metoda tvorby tras přepravní úlohy." Master's thesis, Vysoká škola ekonomická v Praze, 2010. http://www.nusl.cz/ntk/nusl-75633.
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This thesis is focused on optimizing the routes which are implemented in our country at night. Goods are transporting between designated central cities. It deals with creating cyclic routs, along which the goods should be effectively transported, with the respect of the cost. The instruction how to create these paths represents a heuristic method for generating cyclic paths. The algorithm uses the results provided by model that is based on a search for multiple product chart. The chart contains the minimum number of vehicles that provide transport and individual amount of transported goods. The principle of this heuristic method is to create cyclic paths in such a way to be able to serve all transportation requirements with the lowest number of reloads. This approach leads to the fact that the direct paths are preferred.
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Altmanová, Lenka. "Procesorová výroba v rámci logistickeho řetězce firmy." Master's thesis, Vysoká škola ekonomická v Praze, 2008. http://www.nusl.cz/ntk/nusl-10532.
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The paper describes how logistic influence process in the firm, also there is a comparation with other firms in automobile section. And second part describes a case study of job scheduling in a mechanical-engineering production, the goal is to minimise the overall processing time. The production jobs are processed by machines. This problem is treated as a hybrid five-stage flow-shop. In other words, the job-processing job consists of maximum five tasks, it depends on product, because there is 12 products, each has own production flow. It is a new type of flow-shop in which the first-stage scheduling depends upon the time scheduling of the second stage, and so on. A mathematical model and a heuristic method is formulated, The problem is the NP hardness. The case study is solved with the heuristic method and the solution achieved represents a 10% reduction of the processing time for the given set of jobs.
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Kronfeld, Marcel [Verfasser]. "Niching Methods in Heuristic Optimization / Marcel Kronfeld." München : Verlag Dr. Hut, 2011. http://d-nb.info/1017353530/34.
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Rolland, Erik. "Abstract heuristic search methods for graph partitioning." Connect to resource, 1991. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=osu1262633923.
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Hardy, Bradley. "Heuristic methods for colouring dynamic random graphs." Thesis, Cardiff University, 2018. http://orca.cf.ac.uk/109385/.
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Many real-world operational research problems can be reformulated into static graph colouring problems. However, such problems might be better represented as dynamic graphs if their size and/or constraints change over time. In this thesis, we explore heuristics approaches for colouring dynamic random graphs. We consider two di�erent types of dynamic graph: edge dynamic and vertex dynamic. We also consider two di�erent change scenarios for each of these dynamic graph types: without future change information (i. e. random change) and with probabilistic future change information. By considering a dynamic graph as a series of static graphs, we propose a �modi �cation approach� which modi�es a feasible colouring (or solution) for the static representation of a dynamic graph at one time-step into a colouring for the subsequent time-step. In almost all cases, this approach is bene�cial with regards to either improving quality or reducing computational e�ort when compared against using a static graph colouring approach for each time-step independently. In fact, for test instances with small amounts of change between time-steps, this approach can be bene�cial with regards to both quality and computational e�ort When probabilistic future change information is available, we propose a �twostage approach� which �rst attempts to identify a feasible colouring for the current time-step using our �modi�cation approach�, and then attempts to increase the robustness of the colouring with regards to potential future changes. For both the edge and vertex dynamic cases, this approach was shown to decrease the �problematic� change introduced between time-steps. A clear trade-o� can be observed between the quality of a colouring and its potential robustness, such that a colouring with more colours (i. e. reduced quality) can be made more robust.
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Rolland, Eric. "Abstract heuristic search methods for graph partitioning." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1262633923.
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Chraibi, Abdelahad. "A decision making system for operating theater design : application of facility layout problem." Thesis, Saint-Etienne, 2015. http://www.theses.fr/2015STET4017/document.
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Dans les dernières décennies, l'augmentation de la consommation des services de soins et la croissance de la population ont fait de l'élimination du gaspillage et l'amélioration continue de la productivité de plus en plus cruciale pour les hôpitaux. La productivité et l'efficacité d'un hôpital dépendent des conditions de travail des soignants qui sont influencés fortement par l'organisation des lieux de travail et des installations [Dares (2013)]. L’agencement des installations consiste à "déterminer l'organisation physique d'un système de production et de trouver l’arrangement le plus efficace de ‘n’ installations dans ‘n’ positions" [Singh et Sharma (2006)]. L’agencement des installations a un grand impact sur la productivité et l'efficacité du fonctionnement d'un hôpital. Etant conscient de ce besoin, le travail que nous présentons vise à trouver une solution à l’agencement des salles du Bloc Opératoire "le coeur de l'hôpital", ainsi que les salles annexes en proposant un outil intelligent que nous mettons à la disposition des maitres d’ouvrages pour optimiser leur conception du bloc opératoire. Les méthodes que nous avons explorées pour la réalisation de ce travail sont les méthodes exactes, les heuristiques, les métaheuristiques et les méthodes intelligentes, ce qui nous a permis de comparer les différentes approches afin de fournir la meilleure solution pour différents scénarios de problèmes. Nous présentons les contributions majeures de notre travail, à commencer par l'application de la programmation mathématique en nombres entiers mixtes (Mixed Integer Programming (MIP)) pour résoudre le problème d’agencement du bloc opératoire (Operating Theater Layout Problem (OTLP)) comme la première contribution scientifique. Ce travail considère trois structures différentes (multi-section, multi-étage et multi-rangé) dans deux types d'environnement différents, tout en optimisant deux fonctions objectifs différents. La combinaison de ces différentes composantes donne lieu à neuf modèles MIP pour résoudre l’OTLP pour lesquels une solution optimale a été atteinte pour des problèmes avec jusqu'à quarante salles. L'utilisation de Systèmes Multi-Agents (MAS) pour résoudre le problème d’agencement des installations est la deuxième contribution scientifique que nous présentons dans le cinquième chapitre. Dans la littérature, on retrouve un seul travail [Tarkesh et al., (2009)] ayant appliqué le MAS pour résoudre des problèmes de petites tailles, ce qui rend notre travail, le premier adoptant MAS pour répondre à la fois le FLP sous environnement statique et dynamique pour des problèmes de grande taille en utilisant un algorithme en trois étapes pour résoudre OTLP. La plate-forme multi-agents développée exploite les trois différents protocoles de communication d’agents, à savoir la coordination, la coopération et la négociation pour concevoir différentes architectures d’agents afin de faire face à l’OTLP statique et dynamique. La dernière contribution consistant en l'utilisation de l’optimisation par essaim de particules (Particle Swarm Optimization (PSO)) sous une représentation continue de l’espace de recherche pour résoudre le problème d’agencement multi-rangée est présentée dans le sixième chapitre. Puisque la PSO est généralement utilisé pour résoudre les problèmes d’affectation ou les FLP avec une représentation discrète, la formulation actuelle est parmi les rares travaux traitant la représentation continue du FLP. Nous avons conçu une nouvelle technique de codage des particules et des heuristiques appropriées pour générer des solutions initiales et pour effectuer la procédure de recherche locale. Une autre nouveauté est liée à l'application de la PSO à un problème de structure multi-rangé, qui n'a pas été abordé auparavant car à notre connaissance, les travaux avec la PSO ont formulé le FLP comme une structure d’une seule rangée ou dans le meilleur des scénarios, comme une structure à deux rangéesIn the last decades, the important increasing consumption of health care and the growing of population make elimination of waste and continuous productivity improvement more and more critical for hospitals to provide their care services effectively and efficiently. The productivity and efficiency of a hospital depends on the caregivers working conditions, which are impacted greatly by the work place and the facilities organization [Dares (2013)]. Facilities planning “determines the physical organization of a production system and finding the most efficient arrangement of ‘n’ indivisible facilities in ‘n’ locations” [Singh & Sharma (2006)]. Thus, facilities planning has a great impact on the productivity and efficiency of running a hospital. Being aware of this need, the work we present aims to find a solution to facilities planning for the Operating Theater “the heart of hospital” by proposing an intelligent tool we make available to decision makers for optimizing their operating theater design. Our research work focuses on the use of operational research methods in order to find a solution for this optimization problem. Methods we explored for the realization of this work were variant, namely exact algorithm, heuristics, metaheuristics and intelligent methods, which allow us to compare different issues in order to provide the best solution to different scenarios of problems. Thus, in this dissertation we present the major contribution of our work, starting with the application of Mixed Integer Programming (MIP) to solve Operating Theater Layout Problem (OTLP) as the first scientific contribution. This work considers three different formulations (i.e. the multi-sections, the multi-floors and the multi-rows) in two different environment types (i.e. static and dynamic) while optimizing two different objective functions (i.e. to minimize the total traveling cost and to maximize the total adjacency rate). The combination of these different components gives rise to nine MIP models to solve the OTLP for which optimal solution was provided to problems with until forty facilities. These contributions are presented in the third and fourth chapters. The use of Multi-Agent System (MAS) to solve Facility Layout Problem (FLP) is the second scientific contribution we present in chapter five. In literature, only one work [Tarkesh et al., (2009)] applied the MAS to solve small sized problems, which makes our work the first one adopting MAS to address both the static and dynamic FLP for large sized problems using a novel algorithm running in three steps to solve OTLP. The developed multi-agent platform exploit the three different agents’ protocols of communication, namely coordination, cooperation and negotiation to conceive different agents’ architectures to deal with the static and dynamic OTLP. The last contribution consisting on the use of Particle Swarm Optimization (PSO) under continuous layout representation to solve multi-rows FLP is presented in chapter six. Since the PSO is generally used to solve assignment problems or discrete FLP, the actual formulation is among the few works dealing with the continuous one. This leads us to conceive a novel encoding technique and the appropriate heuristics to generate initial solutions and to perform the local search procedure. Another novelty is related to the application of PSO to a multi-rows layout problem, which was not addressed before. To the best of our knowledge, PSO works usually formulate the FLP as a single row or in the best of scenarios, as a double-rows problem
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Cabezas, García José Xavier. "Heuristic methods for solving two discrete optimization problems." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31093.
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In this thesis we study two discrete optimization problems: Traffic Light Synchronization and Location with Customers Orderings. A widely used approach to solve the synchronization of traffic lights on transport networks is the maximization of the time during which cars start at one end of a street and can go to the other without stopping for a red light (bandwidth maximization). The mixed integer linear model found in the literature, named MAXBAND, can be solved by optimization solvers only for small instances. In this manuscript we review in detail all the constraints of the original linear model, including those that describe all the cyclic routes in the graph, and we generalize some bounds for integer variables which so far had been presented only for problems that do not consider cycles. Furthermore, we summarized the first systematic algorithm to solve a simpler version of the problem on a single street. We also propose a solution algorithm that uses Tabu Search and Variable Neighbourhood Search and we carry out a computational study. In addition we propose a linear formulation for the shortest path problem with traffic lights constraints (SPTL). On the other hand, the simple plant location problem with order (SPLPO) is a variant of the simple plant location problem (SPLP) where the customers have preferences on the facilities which will serve them. In particular, customers define their preferences by ranking each of the potential facilities. Even though the SPLP has been widely studied in the literature, the SPLPO has been studied much less and the size of the instances that can be solved is very limited. In this manuscript, we propose a heuristic that uses a Lagrangean relaxation output as a starting point of a semi-Lagrangean relaxation algorithm to find good feasible solutions (often the optimal solution). We also carry out a computational study to illustrate the good performance of our method. Last, we introduce the partial and stochastic versions of SPLPO and apply the Lagrangean algorithm proposed for the deterministic case to then show examples and results.
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Сопілков, Максим Романович. "Система прогнозування виникнення збройних конфліктів за допомогою ймовірнісно-статистичних методів." Master's thesis, Київ, 2018. https://ela.kpi.ua/handle/123456789/23902.
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Магістерська дисертація: 111 с., 19 рис., 30 табл., 2 додатки, 27 джерел.
Об’єкт дослідження – прогнозування сучасних військових конфліктів за допомогою імовірнісно-статистичних методів.
Мета роботи – розробка та дослідження інтелектуальної системи прогнозування потенціального виникнення військового конфлікту у країнах світу , що дає можливість підготуватися до такої ситуації і, в деяких випадках, попередити її.
В роботі розглянуто і проаналізовано прогнозування виникнення сучасних військових (збройних) конфліктів, проаналізовані методи та алгоритми побудови байєсівських та нейронних мереж, їх використання у різноманітних галузях військового моделювання. Розроблено систему побудови прогнозу виникнення військового конфлікту у країні на основі використання методів побудови байєсівських та нейронних мереж.
Система побудови пронозу реалізована за допомогою мови програмування Java (Spring), JavaScript (Angular 2). Точність та правильність роботи системи показують результати наявної політичної ситуації у світі, які ми можемо з вами спостерігати за допомогою засобів масової інформації (ЗМІ).
Результати даної роботи рекомендується використовувати для передбачення виникнення військових збройних конфліктів, що допоможе попередити виникнення даного, або ж по можливості зменшити ризик його виникнення.Theme: “System of forecasting the emergence of armed conflicts via probability statistical methods”. Master’s thesis: 111 p., 19 fig., 30 tab., 2 appendices, 27 sources. The object of study - the prediction of modern military conflicts through bayesian and neural networks. The purpose of the work - research and development of intelligent system of forecasting the potential occurrence of military conflict in the world, which makes it possible to prepare for such situation and, in some cases, prevent it. In this work was reviewed and analyzed next problems: predicting the emergence of modern military (armed) conflict, was analyzed the methods and algorithms of bayesian and neural networks, their use in various fields of military simulation. Also was developed the system of forecasting the emergence of armed conflict in the country using constructing bayesian and neural networks methods. The forecasting system was implemented by using programming languages Java (Spring) and JavaScript (Angular 2). Precision and accuracy of the system shows the results of the political situation in the world which we can observe through the mass media (MSM) The results of this study are recommended for predicting the emergence of armed military conflict that will help prevent them, or as much as possible to reduce the risk of their occurrence.
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Burdová, Jana. "Heuristické a metaheuristické metody řešení úlohy obchodního cestujícího." Master's thesis, Vysoká škola ekonomická v Praze, 2010. http://www.nusl.cz/ntk/nusl-75095.
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Minimal length of a travelling salesman's problem had been studied in this diploma these. Travelling salesman must come trough each place just once and then go back to the starting place. This problem can be illustrated as a problem of graph theory, such that places are the vertices, roads are the edges, distances of roads are the lengths of edges. The optimal travelling salesman's problem tour is the shortest Hamiltionian cycle in the graph. It is a classical NP-complete problem. There is no algorithm that solves this problem in polynomial time. This problem can be solved by using various approximation algorithms, they offer less time consumption and lowest quality than optimization. This diploma these had been dedicated to approximation algorithms, for example: nearest neighbor method, minimal spanning tree method, Christofide's method, 2-opt., genetic algorithm, etc.
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Gondeková, Tatiana. "Optimalizácia investičných rozhodnutí v medzinárodnom prostredí." Master's thesis, Vysoká škola ekonomická v Praze, 2009. http://www.nusl.cz/ntk/nusl-76701.
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In this thesis, a portfolio optimization with integer variables which influence optimal assets allocation in domestic as well as in international environment, is studied. At the beginning with basic terms, assets and portfolio background, incentives of portfolio creation, fields of portfolio application and portfolio management is dealt. Following the characteristics of assets and portfolios (expected return, risk, liquidity), which are used by investors to value their properties, are introduced. Next the mean-risk models are derived for the measures of risk - variance, Value at Risk, Conditional Value at Risk and prepared for a practical application. Heuristics implemented in Matlab and standard algorithms of software GAMS are used for solving problems of the portfolio optimization. At the end optimization methods are applied on real financial data and an outputs are compared.
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Baena, Mirabete Daniel. "Exact and heuristic methods for statistical tabular data protection." Doctoral thesis, Universitat Politècnica de Catalunya, 2017. http://hdl.handle.net/10803/456809.
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One of the main purposes of National Statistical Agencies (NSAs) is to provide citizens or researchers with a large amount of trustful and high quality statistical information. NSAs must guarantee that no confidential individual information can be obtained from the released statistical outputs. The discipline of Statistical disclosure control (SDC) aims to avoid that confidential information is derived from data released while, at the same time, maintaining as much as possible the data utility. NSAs work with two types of data: microdata and tabular data. Microdata files contain records of individuals or respondents (persons or enterprises) with attributes. For instance, a national census might collect attributes such as age, address, salary, etc. Tabular data contains aggregated information obtained by crossing one or more categorical variables from those microdata files. Several SDC methods are available to avoid that no confidential individual information can be obtained from the released microdata or tabular data. This thesis focus on tabular data protection, although the research carried out can be applied to other classes of problems. Controlled Tabular Adjustment(CTA) and Cell Suppression Problem (CSP) have concentrated most of the recent research in the tabular data protection field. Both methods formulate Mixed Integer Linear Programming problems (MILPs) which are challenging for tables of moderate size. Even finding a feasible initial solution may be a challenging task for large instances. Due to the fact that many end users give priority to fast executions and are thus satisfied, in practice, with suboptimal solutions, as a first result of this thesis we present an improvement of a known and successful heuristic for finding feasible solutions of MILPs, called feasibility pump. The new approach, based on the computation of analytic centers, is named the Analytic Center Feasbility Pump.The second contribution consists in the application of the fix-and-relax heuristic (FR) to the CTA method. FR (alone or in combination with other heuristics) is shown to be competitive compared to CPLEX branch-and-cut in terms of quickly finding either a feasible solution or a good upper bound. The last contribution of this thesis deals with general Benders decomposition, which is improved with the application of stabilization techniques. A stabilized Benders decomposition is presented,which focus on finding new solutions in the neighborhood of "good'' points. This approach is efficiently applied to the solution of realistic and real-world CSP instances, outperforming alternative approaches.The first two contributions are already published in indexed journals (Operations Research Letters and Computers and Operations Research). The third contribution is a working paper to be submitted soon.Un dels principals objectius dels Instituts Nacionals d'Estadística (INEs) és proporcionar, als ciutadans o als investigadors, una gran quantitat de dades estadístiques fiables i precises. Al mateix temps els INEs deuen garantir la confidencialitat estadística i que cap dada personal pot ser obtinguda gràcies a les dades estadístiques disseminades. La disciplina Control de revelació estadística (en anglès Statistical Disclosure Control, SDC) s'ocupa de garantir que cap dada individual pot derivar-se dels outputs de estadístics publicats però intentant al mateix temps mantenir el màxim possible de riquesa de les dades. Els INEs treballen amb dos tipus de dades: microdades i dades tabulars. Les microdades son arxius amb registres individuals de persones o empreses amb un conjunt d'atributs. Per exemple, el censos nacional recull atributs tals com l'edat, sexe, adreça o salari entre d'altres. Les dades tabulars són dades agregades obtingudes a partir del creuament d’un o més atributs o variables categòriques dels fitxers de microdades. Varis mètodes CRE són disponibles per evitar la revelació estadística en fitxers de microdades o dades tabulars. Aquesta tesi es centra en la protecció de dades tabulars tot i que la recerca duta a terme pot ser aplicada també a altres tipus de problemes. Els mètodes CTA (en anglès Controlled Tabular Adjustment) i CSP (en anglès Cell Suppression Problem) ha centrat la major part de la recerca feta en el camp de protecció de dades tabulars. Tots dos mètodes formulen problemes MILP (Mixed Integer Linear Programming problems) difícils de solucionar en taules de mida moderada. Fins i tot trobar solucions inicials factibles pot resultar molt difícil. Donat el fet que molts usuaris finals donen prioritat a tenir solucions ràpides i bones tot i que aquestes no siguin les òptimes, la primera contribució de la tesis presenta una millora en una coneguda i exitosa heurística per trobar solucions factibles de MILPs, anomenada feasibility pump. La nova aproximació, basada en el càlcul de centres analítics, s'anomena Analytic Center Feasibility Pump. La segona contribució consisteix en l'aplicació de la heurística fix-and-relax (FR) al mètode CTA. FR (sol o en combinació amb d'altres heurístiques) es mostra com a competitiu davant CPLEX branch-and-cut en termes de trobar ràpidament solucions factibles o bons upper bounds. La darrera contribució d’aquesta tesi tracta sobre el problema general de descomposició de Benders, aportant una millora amb l'aplicació de tècniques d’estabilització. Presentem un mètode anomenat stabilized Benders decomposition que es centra en trobar noves solucions properes a punts considerats prèviament com a bons. Aquesta aproximació ha estat eficientment aplicada al problema CSP, obtenint molt bons resultats en dades tabulars reals, millorant altres alternatives conegudes del mètode CSP. Les dues primeres contribucions ja han estat publicades en revistes indexades (Operations Research Letters and Computers and Operations Research). Actualment estem treballant en la publicació de la tercera contribució i serà en breu enviada a revisar.
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Mahtani, Pravesh. "Heuristic methods for backup lightpath routing in WDM networks." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ63021.pdf.
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Eusuff, Muzaffar M. "Water resources decision making using meta-heuristic optimization methods." Diss., The University of Arizona, 2004. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_2004_051_sip1_w.pdf&type=application/pdf.
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Sariklis, Dimitrios. "Open Vehicle Routing Problem : description, formulations and heuristic methods." Thesis, London School of Economics and Political Science (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265252.
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Tan, Jin C. "Leg-based heuristic methods to network seat inventory control." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/12116.
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Jung, Wolfgang. "Instrumente räumlicher Planung : Systematisierung und Wirkung auf die Regimes und Budgets der Adressaten /." Hamburg : Kovač, 2008. http://www.verlagdrkovac.de/978-3-8300-3743-9.htm.
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Künzelová, Barbora. "Rozvozní problém s heterogenními vozidly." Master's thesis, Vysoká škola ekonomická v Praze, 2014. http://www.nusl.cz/ntk/nusl-193549.
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The master's thesis deals with the new modification of vehicle routing problem -- 3PL vehicle routing problem with heterogeneous fleet and split delivery. In addition to classical vehicle routing problem, we consider a heterogeneous suppliers fleet and also external carrier, which charges a fixed value per unit of transported goods. The reader is first introduces to vehicle routing problem, its history and possible solutions. Furthermore, the reader is acquainted with logistics and logistics providers. In the main part of this thesis is described 3PL vehicle routing problem and its mathematical model. At first we try to get optimal solution via CPLEX solver. But since this is an NP-hard task, heuristic method is proposed (in two variants) for solving this problem. The heuristic is then tested on the selected test tasks. Results obtained using the proposed heuristics are compared with the optimal solution. Even larger problems are then solved using this heuristics. In the end other modifications and possible improvements of this heuristic method are proposed.
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Slavíková, Monika. "Aplikace heuristických metod v reálném rozvozním problému." Master's thesis, Vysoká škola ekonomická v Praze, 2014. http://www.nusl.cz/ntk/nusl-194501.
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This thesis is continuation of the bachelor thesis "Model of delivery routes and placement logistics centers with opportunities of their optimization". It is about distribution problems and specifically a vehicle routing problem. The aim of this thesis is finding a solution of the vehicle routing problem which will be used repeatedly in the firm. The main task is achieving the lowest costs (total kilometers) with maximum utilization of vehicle capacity; in such conditions that all requirements of logistics centers will be satisfied and maximal capacity of vehicle will be tolerated. For calculation was used a solver Gurobi 6.0.3 in system MPL for Windows 4.2, which won't, however, provide the optimal solution and problem solving takes too long time. Next for calculation was used heuristics insert method and is written by VBA (Visual Basic for Applications) in MS Excel. Finally, there is a comparison of these methods with the original solution of the vehicle routing plan and solution of the bachelor thesis. Then the computational experiment was done, which tested effect to result, if other distribution center (starting point) will be bulit. The computational experiment was consist from heuristic insert method, solver Gurobi and heuristic saving algorithm from bachelor thesis.