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Dissertations / Theses on the topic 'Constraints handling'

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Published: 5 June 2025

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Betz, Hariolf, Frank Raiser, and Thom Frühwirth. "Persistent constraints in constraint handling rules." Universität Potsdam, 2010. http://opus.kobv.de/ubp/volltexte/2010/4154/.

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In the most abstract definition of its operational semantics, the declarative and concurrent programming language CHR is trivially non-terminating for a significant class of programs. Common refinements of this definition, in closing the gap to real-world implementations, compromise on declarativity and/or concurrency. Building on recent work and the notion of persistent constraints, we introduce an operational semantics avoiding trivial non-termination without compromising on its essential features.

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Luo, Yongping. "Handling motion processing constraints for articulated figure animation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq24190.pdf.

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Mendler, M. "A modal logic for handling behavioural constraints in formal hardware verification." Thesis, University of Edinburgh, 1992. http://hdl.handle.net/1842/15374.

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The application of formal methods to the design of correct computer hardware depends crucially on the use of abstraction mechanisms to partition the synthesis and verification task into tractable pieces. Unfortunately however, behavioural abstractions are genuine mathematical abstractions only up to behavioural constraints, i.e. under certain restrictions imposed on the device's environment. Timing constraints on input signals form an important class of such restrictions. Hardware components that behave properly only under such constraints satisfy their abstract specifications only approximately. This is an impediment to the naive approach to formal verification since the question of how to apply a theorem prover when one only knows approximately what formula to prove has not as yet been dealt with. In this thesis we propose, as a solution, to interpret the notion of 'correctness up to constraint' as a modality of intuitionistic predicate logic so as to remove constraints from the specification and to make them part of its proof. This provides for an 'approximate' verification of abstract specifications and yet does not compromise the rigour of the argument since a realizability semantics can be used to extract the constraints. Also, the abstract verification is separated from constraint analysis which in turn may be delayed arbitrarily. In the proposed framework constraint analysis comes down to proof analysis and a computational semantics on proofs may be used to manipulate and simplify constraints.

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Kåhlman, Johan, and Josef Spånberger. "Dynamic constraint handling in mass customization systems : A database solution." Thesis, Tekniska Högskolan, Jönköping University, JTH, Datateknik och informatik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-50445.

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Purpose: The purpose of this study is to develop an architecture for a Mass Customization information system that allows for product customization restrictions being dynamically expressed through the database. Method: A study evaluating an artifact made using Design Science Research. The evaluation was made using both a quantitative and a qualitative method. Findings: Building upon a literature review to establish a knowledge base, an artifact was created using React and Node.js to build a web application combined with a Neo4j graph database. The artifact allows for products and their inherent restrictions to be dynamically added and modified through constraints defined in their data. This data can be used in the web application to assemble and customize components, where the constraints can be enforced by the web application in real time without any modification to the application. The artifact can enforce all constraints that were intended and it was considered as a better overall solution for handling constraints compared to the currently used solution by Divid, a market leading company in the usage of Mass Customization systems with constraint handling in the context of ventilation systems. Implications: The results implicate that the usage of graph database systems in Mass Customization systems holds great promise, specifically as a new way to handle constraints between components dynamically. Limitations: The results from the expert panel only reflects the opinions of Divid and might not be true for other companies interested in this area. The artifact solution was successful in its purpose to illustrate the concept of dynamic constraint handling. However, it is still unclear if the system holds up in a professional context with more complex rules and heavy demands on performance.

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Beaumont, Matthew, and n/a. "Handling Over-Constrained Temporal Constraint Networks." Griffith University. School of Information Technology, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20041213.084512.

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Temporal reasoning has been an active research area for over twenty years, with most work focussing on either enhancing the efficiency of current temporal reasoning algorithms or enriching the existing algebras. However, there has been little research into handling over-constrained temporal problems except to recognise that a problem is over-constrained and then to terminate. As many real-world temporal reasoning problems are inherently over-constrained, particularly in the scheduling domain, there is a significant need for approaches that can handle over-constrained situations. In this thesis, we propose two backtracking algorithms to gain partial solutions to over-constrained temporal problems. We also propose a new representation, the end-point ordering model, to allow the use of local search algorithms for temporal reasoning. Using this model we propose a constraint weighting local search algorithm as well as tabu and random-restart algorithms to gain partial solutions to over-constrained temporal problems. Specifically, the contributions of this thesis are: The introduction and empirical evaluation of two backtracking algorithms to solve over-constrained temporal problems. We provide two backtracking algorithms to close the gap in current temporal research to solve over-constrained problems; The representation of temporal constraint networks using the end-point ordering model. As current representation models are not suited for local search algorithms, we develop a new model such that local search can be applied efficiently to temporal reasoning; The development of a constraint weighting local search algorithm for under-constrained problems. As constraint weighting has proven to be efficient for solving many CSP problems, we implement a constraint weighting algorithm to solve under-constrained temporal problems; An empirical evaluation of constraint weighting local search against traditional backtracking algorithms. We compare the results of a constraint weighting algorithm with traditional backtracking approaches and find that in many cases constraint weighting has superior performance; The development of a constraint weighting local search, tabu search and random-restart local search algorithm for over-constrained temporal problems. We extend our constraint weighting algorithm to solve under-constrained temporal problems as well as implement two other popular local search algorithms: tabu search and random-restart; An empirical evaluation of all three local search algorithms against the two backtracking algorithms. We compare the results of all three local search algorithms with our twobacktracking algorithms for solving over-constrained temporal reasoning problems and find that local search proves to be considerably superior.

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Beaumont, Matthew. "Handling Over-Constrained Temporal Constraint Networks." Thesis, Griffith University, 2004. http://hdl.handle.net/10072/366603.

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Triossi, Andrea <1979&gt. "Hardware execution of constraint handling rules." Doctoral thesis, Università Ca' Foscari Venezia, 2012. http://hdl.handle.net/10579/1232.

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In this thesis we want to investigate the compiling of the well-established language Constraint Handling Rule (CHR) to a low level hardware description language (HDL). The benefit introduced by a CHR-based hardware synthesis is twofold: it increases the abstraction level of the common synthesis work-flow and it can give significant speed up to the execution of a CHR program in terms of computational time. We want to propose a method that sets CHR as a starting point for a hardware description. The developed hardware will be able to turn all the intrinsic concurrency of the language into parallelism. The rules application is mainly achieved by a custom executor that handles constraints according to the best degree of parallelism the implemented CHR specification can offer. Afterwards we want to integrate the generated hardware code, deployed in a Field Programmable Gate Array (FPGA), within the traditional software execution model of CHR. The result will be a prototype system consisting of a CHR execution engine composed of a general purpose processor coupled with a specialized hardware accelerator. The former will execute a CHR specification while the latter will unburden the processor by executing in parallel the most computational intensive rules. Finally the performance of the proposed system architecture will be validated by time efficiency measures. In questa tesi si vuole investigare la compilazione dell'ormai consolidato linguaggio Constraint Handling Rules (CHR) in un hardware description language (HDL) a basso livello. Il vantaggio introdotto da una sintesi di hardware basata su CHR è duplice: permette di aumentare il livello di astrazione del tradizionale processo di sintesi di hardware e può dare accelerazioni significative all'esecuzione di un programma CHR in termini di tempo di computazione. Viene proposto un metodo che parte da CHR per effettuare una descrizione dell'hardware. L'hardware sviluppato sarà in grado di convertire tutta la concorrenza intrinseca al linguaggio in parallelismo. L'applicazione delle regole viene realizzata tramite uno speciale esecutore che tratta i vincoli in modo da effettuare il più alto grado di parallelismo che il programma CHR implementato possa offrire. Successivamente si vuole integrare il codice hardware così sviluppato, e caricato in una Field Programmable Gate Array (FPGA), con il tipico modello di esecuzione di CHR. Ne risulterà un prototipo di un motore di esecuzione basato su CHR e composto da un generico processore accoppiato con uno specifico acceleratore hardware. Il primo eseguirà un programma CHR, mentre il secondo libererà il processore dall'esecuzione delle regole più computazionalmente pesanti tramite la loro parallelizzazione. In conclusione le prestazioni delle architetture proposte saranno avvalorate da misure di efficienza temporale.

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Abdennadher, Slim, Haythem Ismail, and Frederick Khoury. "Transforming imperative algorithms to constraint handling rules." Universität Potsdam, 2010. http://opus.kobv.de/ubp/volltexte/2010/4153/.

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Different properties of programs, implemented in Constraint Handling Rules (CHR), have already been investigated. Proving these properties in CHR is fairly simpler than proving them in any type of imperative programming language, which triggered the proposal of a methodology to map imperative programs into equivalent CHR. The equivalence of both programs implies that if a property is satisfied for one, then it is satisfied for the other. The mapping methodology could be put to other beneficial uses. One such use is the automatic generation of global constraints, at an attempt to demonstrate the benefits of having a rule-based implementation for constraint solvers.

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Ramde, Sara, and Lana Qadir. "Effektivisering av materialflödet i inlagringsprocessen i ett distributionslager : Genom exkludering av begränsningar." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Industriell organisation och produktion, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-41781.

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Syfte – Syftet med studien är att identifiera kritiska begränsningar i inlagringsprocessen i ett distributionslager för att därmed kunna effektivisera materialflödet. Studiens syfte uppnås genom att följande forskningsfrågor har formulerats: Vilka kritiska begränsningar kan förekomma i materialflödet i en inlagringsprocess i ett distributionslager? Hur kan de identifierade begränsningarna exkluderas i en inlagringsprocess? Metod – Studien hade en induktiv ansats och datainsamling skedde genom intervjuer, observationer, dokumentstudier och litteraturstudier. En fallstudie genomfördes på ett distributionslager och empiri och teori har jämförts för att kunna uppfylla studiens syfte. Resultat – Studiens resultat påvisar att de förekommande kritiska begränsningarna i ett distributionslager är brist på yta, materialhantering, automatiska system samt lagerlayout. Studiens slutsats är att begränsningarna är sammankopplade och påverkar varandra eftersom de ingår i samma process. För att exkludera begränsningarna bör distributionslager implementera diverse standarder i sin inlagringsprocess och arbeta med ständiga förbättringar. Implikationer – Studien bidrar inte med nya teorier men bidrar med praktisk nytta för distributionslager med liknande kriterier som studiens fallföretag. Begränsningar – Studien riktar enbart in sig på distributionslager och var en fallstudie av enfallsdesign. Genom att utföra flera liknande undersökningar på företag med liknande kriterier hade generaliserbarheten kunnat stärkas. Purpose – The purpose of the study is to identify critical constraints in the inbound process at a distribution warehouse. To accomplish the purpose two research questions were formulated: Which critical constraints can occur in the material flow in the inbound process at a distribution warehouse? How can the identified constraints be excluded in the inbound process? Method – The study was performed inductively, and the data collection techniques were interviews, observations, document studies and literature studies. A single case study was performed at a distribution warehouse and the empirical data and theories were compared to accomplish the purpose of the study. Findings – The result of the study demonstrates that the critical constraints in the inbound process at a distribution warehouse are space, material handling, automatic systems and warehouse layout. The conclusion of the study is that the constraints are connected and affect each other since they are all included in the same process. To exclude the constraints different types of standards should be implemented in the inbound process, and distribution warehouses should work with continuous improvements. Implications – The study does not contribute to new theories but can be practically beneficial for distribution warehouses similar to the studies case study. Limitations – The study only focuses on one distribution warehouse and is therefore a single case study. The generalizability could have been higher if the study had been conducted at multiple distribution warehouses.

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Kim, Dae Gyu. "Mapping based constraint handling methods for evolutionary algorithms." Thesis, University of Sussex, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311406.

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Parr, James. "Improvement criteria for constraint handling and multiobjective optimization." Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/349978/.

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In engineering design, it is common to predict performance based on complex computer codes with long run times. These expensive evaluations can make automated and wide ranging design optimization a difficult task. This becomes even more challenging in the presence of constraints or conflicting objectives. When the design process involves expensive analysis, surrogate (response surface or meta) models can be adapted in different ways to efficiently converge towards global solutions. A popular approach involves constructing a surrogate based on some initial sample evaluated using the expensive analysis. Next, some statistical improvement criterion is searched inexpensively to find model update points that offer some design improvement or model refinement. These update points are evaluated, added to the set of initial designs and the process is repeated with the aim of converging towards the global optimum. In constrained problems, the improvement criterion is required to update the surrogate models in regions that offer both objective and constraint improvement whilst converging toward the best feasible optimum. In multiobjective problems, the aim is to update the surrogates in such a way that the evaluated points converge towards a spaced out set of Pareto solutions. This thesis investigates efficient improvement criteria to address both of these situations. This leads to the development of an improvement criterion that better balances improvement of the objective and all the constraint approximations. A goal-based approach is also developed suitable for expensive multiobjective problems. In all cases, improvement criteria are encouraged to select multiple updates, enabling designs to be evaluated in parallel, further accelerating the optimization process.

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SILVA, Marcos Aurélio Almeida da. "CHORD: constraint handling object-oriented rules with disjunctions." Universidade Federal de Pernambuco, 2009. https://repositorio.ufpe.br/handle/123456789/1955.

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Made available in DSpace on 2014-06-12T15:53:28Z (GMT). No. of bitstreams: 2 arquivo1916_1.pdf: 1434494 bytes, checksum: 1b590044040a8dcd13c8953148aade5a (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Constraint Handling Object-oriented Rules with Disjunctions (CHORD), é uma extensão orientada a objetos (OO) de CHRv, uma linguagem relacional baseada em regras que foi inicialmente desenhada para a especificação em caixa branca de resolvedores de restrições mas veio a mostrar-se uma linguagem bastante flexível. Flexibilidade esta que vêm sendo demonstrada nos últimos anos pelo grande número de serviços de raciocínio e algoritmos que foram descritos concisamente por meio desta linguagem. Para definir a sintaxe de nossa extensão, nós nos baseamos na abordagem seguida na extensão de Prolog realizada por Frame Logic que é similar à nossa, na qual, a sintaxe de frames foi introduzida para representar construtores OO em cima dos relacionais originais. Além disso, em vez de forçar o usuário (programador) a se adequar à uma semântica pré-definida para esses novos construtores, nós escolhemos uma estratégia inovadora: desacoplar a sintaxe da semântica da linguagem permitindo que o conjunto de hipóteses semânticas seja totalmente configurável. Estes avanços claramente contribuem para o domínio do Raciocínio Automático e da Representação do Conhecimento (AR/KR), dentro do qual CHRv é a linguagem de representa ção do conhecimento mais versátil. Este trabalho também permite a integração dos serviços de raciocínio já providos por CHRv ao estado da arte em linguagens orientadas a objetos reduzindo a quebra de paradigma entre elas. Há também contribuições a outros domínios: em programação declarativa, ao disponibilizar a primeira linguagem a integrar as formas mais poderosas de programação orientada a objetos, baseada em regras e baseada em restrições. No domínio da Web Semântica, nós mostramos que nossa linguagem generaliza a semântica de três dos mais importantes padrões de linguagem de representação do conhecimento, provendo uma solução para o problema recorrente de integração nesta área. No domínio da engenharia guiado por modelos (MDE), este trabalho provê o primeiro mapeamento semântico para modelos UML/OCL, MOF/OCL e transformações de modelo explícitamente configurável e com fundamentação axiomática declarativa e operacional em CFOL. Neste trabalho nós apresentamos as sintaxes abstrata e contreta de CHORD, suas semânticas operacional e declarativa em CFOL, e uma ontologia de hipóteses semânticas para herança. Para validá-lo, nós apresentamos três estudos de caso mostrando que CHORD generaliza UML/OCL, Frame Logic e OWL

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Tacchella, Paolo <1976&gt. "Constraint handling rules. Compositional semantics and program transformation." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/912/1/Tesi_Tacchella_Paolo.pdf.

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This thesis intends to investigate two aspects of Constraint Handling Rules (CHR). It proposes a compositional semantics and a technique for program transformation. CHR is a concurrent committed-choice constraint logic programming language consisting of guarded rules, which transform multi-sets of atomic formulas (constraints) into simpler ones until exhaustion [Frü06] and it belongs to the declarative languages family. It was initially designed for writing constraint solvers but it has recently also proven to be a general purpose language, being as it is Turing equivalent [SSD05a]. Compositionality is the first CHR aspect to be considered. A trace based compositional semantics for CHR was previously defined in [DGM05]. The reference operational semantics for such a compositional model was the original operational semantics for CHR which, due to the propagation rule, admits trivial non-termination. In this thesis we extend the work of [DGM05] by introducing a more refined trace based compositional semantics which also includes the history. The use of history is a well-known technique in CHR which permits us to trace the application of propagation rules and consequently it permits trivial non-termination avoidance [Abd97, DSGdlBH04]. Naturally, the reference operational semantics, of our new compositional one, uses history to avoid trivial non-termination too. Program transformation is the second CHR aspect to be considered, with particular regard to the unfolding technique. Said technique is an appealing approach which allows us to optimize a given program and in more detail to improve run-time efficiency or spaceconsumption. Essentially it consists of a sequence of syntactic program manipulations which preserve a kind of semantic equivalence called qualified answer [Frü98], between the original program and the transformed ones. The unfolding technique is one of the basic operations which is used by most program transformation systems. It consists in the replacement of a procedure-call by its definition. In CHR every conjunction of constraints can be considered as a procedure-call, every CHR rule can be considered as a procedure and the body of said rule represents the definition of the call. While there is a large body of literature on transformation and unfolding of sequential programs, very few papers have addressed this issue for concurrent languages. We define an unfolding rule, show its correctness and discuss some conditions in which it can be used to delete an unfolded rule while preserving the meaning of the original program. Finally, confluence and termination maintenance between the original and transformed programs are shown. This thesis is organized in the following manner. Chapter 1 gives some general notion about CHR. Section 1.1 outlines the history of programming languages with particular attention to CHR and related languages. Then, Section 1.2 introduces CHR using examples. Section 1.3 gives some preliminaries which will be used during the thesis. Subsequentely, Section 1.4 introduces the syntax and the operational and declarative semantics for the first CHR language proposed. Finally, the methodologies to solve the problem of trivial non-termination related to propagation rules are discussed in Section 1.5. Chapter 2 introduces a compositional semantics for CHR where the propagation rules are considered. In particular, Section 2.1 contains the definition of the semantics. Hence, Section 2.2 presents the compositionality results. Afterwards Section 2.3 expounds upon the correctness results. Chapter 3 presents a particular program transformation known as unfolding. This transformation needs a particular syntax called annotated which is introduced in Section 3.1 and its related modified operational semantics !0t is presented in Section 3.2. Subsequently, Section 3.3 defines the unfolding rule and prove its correctness. Then, in Section 3.4 the problems related to the replacement of a rule by its unfolded version are discussed and this in turn gives a correctness condition which holds for a specific class of rules. Section 3.5 proves that confluence and termination are preserved by the program modifications introduced. Finally, Chapter 4 concludes by discussing related works and directions for future work.

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Zini, Érico de Oliveira Costa. "Algoritmo genético especializado na resolução de problemas com variáveis contínuas e altamente restritos /." Ilha Solteira : [s.n.], 2009. http://hdl.handle.net/11449/87116.

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Resumo: Este trabalho apresenta uma metodologia composta de duas fases para resolver problemas de otimização com restrições usando uma estratégia multiobjetivo. Na primeira fase, o esforço concentra-se em encontrar, pelo menos, uma solução factível, descartando completamente a função objetivo. Na segunda fase, aborda-se o problema como biobjetivo, onde se busca a otimização da função objetivo original e maximizar o cumprimento das restrições. Na fase um propõe-se uma estratégia baseada na diminuição progressiva da tolerância de aceitação das restrições complexas para encontrar soluções factíveis. O desempenho do algoritmo é validado através de 11 casos testes bastantes conhecidos na literatura especializada. Abstract: This work presents a two-phase framework for solving constrained optimization problems using a multi-objective strategy. In the first phase, the objective function is completely disregarded and entire search effort is directed toward finding a single feasible solution. In the second phase, the problem is treated as a bi-objective optimization problem, where the technique converts constrained optimization to a two-objective optimization: one is the original objective function; the other is the degree function violating the constraints. In the first phase a methodology based on progressive decrease of the tolerance of acceptance of complex constrains is proposed in order to find feasible solutions. The approach is tested on 11 well-know benchmark functions. Orientador: Rubén Augusto Romero Lázaro Coorientador: José Roberto Sanches Mantovani Banca: Antonio Padilha Feltrin Banca: Marcos Julio Rider Flores Mestre

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Puerta, Marcus Vinicius [UNESP]. "A utilização dos conceitos de manufatura enxuta e da teoria das restrições no abastecimento de uma linha de montagem." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/143417.

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Submitted by MARCUS VINICIUS PUERTA null (mvpuerta@gmail.com) on 2016-08-22T19:55:29Z No. of bitstreams: 1 Dissertação MVP Final.pdf: 3273798 bytes, checksum: b791361123375f0b442593d8b7acae86 (MD5) Rejected by Ana Paula Grisoto (grisotoana@reitoria.unesp.br), reason: Solicitamos que realize uma nova submissão com o arquivo correto. Agradecemos a compreensão. on 2016-08-23T12:44:16Z (GMT) Submitted by MARCUS VINICIUS PUERTA (mvpuerta@gmail.com) on 2016-08-23T15:19:31Z No. of bitstreams: 1 Dissertação MVP Final.pdf: 3359235 bytes, checksum: 885367a13dfa3a719a6d5d176985a236 (MD5) Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-08-24T17:00:02Z (GMT) No. of bitstreams: 1 puerta_mv_me_guara.pdf: 3359235 bytes, checksum: 885367a13dfa3a719a6d5d176985a236 (MD5) Made available in DSpace on 2016-08-24T17:00:02Z (GMT). No. of bitstreams: 1 puerta_mv_me_guara.pdf: 3359235 bytes, checksum: 885367a13dfa3a719a6d5d176985a236 (MD5) Previous issue date: 2016-06-24 O grande número de competidores globais existentes no mercado tem levado as indústrias da cadeia automotiva a buscarem incessantemente melhorias na gestão operacional, e nesse sentido esse trabalho apresenta uma proposta de integração das técnicas e abordagens da Manufatura Enxuta e da Teoria das Restrições, através de uma aplicação prática, visando a melhoria da sistemática de abastecimento de componentes para utilização em células de solda pertencentes a uma linha de montagem de chassis. Em uma primeira etapa foram apresentados os conceitos e as possibilidades de integração de ambas as teorias e, a partir de um diagnóstico inicial do sistema de abastecimento, foram propostas alterações, de maneira evolutiva, em que melhorias baseadas na Manufatura Enxuta eram implementadas a cada rodada de experimento, culminando com a implementação de melhorias baseadas na Teoria das Restrições, integrando ambos os conceitos. O resultado final obtido corrobora a eficiência da integração das duas abordagens para a melhoria de processos, as quais contribuíram para uma diminuição dos tempos de ciclo de abastecimento na ordem de 89% para a célula alvo estudada, sendo superior ao resultado obtido utilizando-se apenas uma das técnicas, sem que houvesse necessidade de investimentos e/ou despesas significativas. The large number of global players in the market has led the automotive industry chain to incessantly seek improvements in operations management to increase their results and, based on this fact, this paper presents a proposal for integrating the techniques and approaches of Lean Manufacturing and Theory of Constraints through an action research application, aiming at improving the material supply system of welding cells from a chassis frame assembly line. In the first stage were presented the concepts and possibilities of integration of both theories and, from an initial diagnosis of the supply system, changes were proposed in an evolutionary way, in which improvements based on Lean Manufacturing were implemented on each experiment round, culminating in the implementation of improvements based on the Theory of Constraints, integrating both concepts. The final result confirms the efficiency of the integration of these two approaches as a way to improve processes, which contributed to an 89% decrease of the supply cycle times of the studied target cell. This result is better than the result obtained using only one of the techniques, without the need for investments and / or significant expenses.

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Mário, Oliveira Rodrigues Cleyton. "Component assembly and theorem proving in constraint handling rules." Universidade Federal de Pernambuco, 2009. https://repositorio.ufpe.br/handle/123456789/1821.

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Made available in DSpace on 2014-06-12T15:52:36Z (GMT). No. of bitstreams: 1 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 Devido á grande demanda por softwares cada vez mais robustos, complexos e flexíveis, e, sobretudo, pelo curtíssimo tempo de entrega exigido, a engenharia de software tem procurado novos meios de desenvolvimento que supram satisfatoriamente essas demandas. Uma forma de galgar esses novos patamares de produtividade provém do uso de uma metodologia baseada em agentes que se comunicam e com isso, ao invés dos programas serem estritamente programados, o comportamento destes sistemas de software emerge da interação de agentes, robôs, ou subsistemas aut onomos, independentes, além de declarativamente especificados. Isto provê a habilidade para automaticamente configurá -los, otimizá-los, monitorá-los, adaptá-los, diagnosticá-los, repará-los e protegê-los dentro do ambiente. Contudo, um grande problema das linguagens declarativas é a falta de mecanismos que permitem a melhor estruturação de dados, facilitando portanto, o reuso. Portanto, esta dissertação explica o desenvolvimento de nova linguagem lógica declarativa para programar sistemas de raciocínio automático de uma forma modularizada: C2HR∨. A linguagem base escolhida para a extensão com componentes lógicos foi CHR. Os motivos para essa escolha são definidos ao longo da dissertação. Duas abordagens, portanto, são apresentadas: a primeira, conhecida como CHRat, foi desenvolvida numa parceria juntamente com o grupo de pesquisas CONTRAINTES do INRIA/Rocquencourt-Paris, onde o programador ´e o responsável direto por definir os componentes CHR, permitindo o seu reuso por outros componentes; a segunda aplicação, CHRtp, visa atender prioritariamente requisitos de completude e, por isso, se baseia em procedimentos lógicos de inferência como: o raciocínio para frente, o raciocínio para trás, e a resolução/factoring. A dissertação mostra também alguns exemplos práticos, onde uso de componentes facilita radicalmente sua implementação. As contribuições almejadas com essa dissertação são: a definição de uma família bem formalizada de provadores de teoremas automáticos, que podem trabalhar com sentenças especificadas em lógica horn ou em lógica de primeira ordem, a extensão de CHR como uma linguagem modular de propósito geral, a melhor estruturação de bases conhecimentos e até o uso em conjunto de bases heterogêneas, a definição de uma linguagem para a fácil e direta estruturação de dados por meio de componentes, dentre outras

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Gall, Daniel [Verfasser]. "Analysis of cognitive models in constraint handling rules / Daniel Gall." Ulm : Universität Ulm, 2021. http://d-nb.info/1239737181/34.

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Sharaf, Nada [Verfasser]. "CHRvis: an animation extension for animating constraint handling rules / Nada Sharaf." Ulm : Universität Ulm, 2019. http://d-nb.info/1190727315/34.

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Betz, Hariolf Karl Michael [Verfasser]. "A unified analytical foundation for constraint handling rules / Hariolf Karl Michael Betz." Ulm : Universität Ulm. Fakultät für Ingenieurwissenschaften und Informatik, 2014. http://d-nb.info/1053381409/34.

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Campher, Andre Herman. "A systematic approach to model predictive controller constraint handling : rigorous geometric methods." Diss., University of Pretoria, 2011. http://hdl.handle.net/2263/28378.

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The models used by model predictive controllers (MPCs) to predict future outcomes are usually unconstrained forms like impulse or step responses and discrete state space models. Certain MPC algorithms allow constraints to be imposed on the inputs or outputs of a system; but they may be infeasible as they are not checked for consistency via the process model. Consistent constraint handling methods - which account for their interdependence and disambiguate the language used to specify constraints – would therefore be an attractive aid when using any MPC package. A rigorous and systematic approach to constraint management has been developed, building on the work of Vinson (2000), Lima (2007) and Georgakis et al. (2003) in interpreting constraint interactions. The method supports linear steady-state system models, and provides routines to obtain the following information: <ul> <li> effects of constraint changes on the corresponding input and output constraints, </li><li> feasibility checks for constraints, </li><li> specification of constraint-set size and</li><li> optimal fitting of constraints within the desirable input and output space.</li></ul> Mathematical rigour and unambiguous language for identifying constraint types were key design criteria. The outputs of the program provide guidance when handling constraints, as opposed to rules of thumb and experience, and promote understanding of the system and its constraints. The metrics presented are not specific to any commercial MPC and can be implemented in the user interfaces of such MPCs. The method was applied to laboratory-scale test rigs to illustrate the information obtained. Dissertation (MEng)--University of Pretoria, 2011. Chemical Engineering unrestricted

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Betz, Hariolf [Verfasser]. "A unified analytical foundation for constraint handling rules / Hariolf Karl Michael Betz." Ulm : Universität Ulm. Fakultät für Ingenieurwissenschaften und Informatik, 2014. http://d-nb.info/1053381409/34.

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Zini, Érico de Oliveira Costa [UNESP]. "Algoritmo genético especializado na resolução de problemas com variáveis contínuas e altamente restritos." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/87116.

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Made available in DSpace on 2014-06-11T19:22:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-20Bitstream added on 2014-06-13T19:28:05Z : No. of bitstreams: 1 zini_eoc_me_ilha.pdf: 1142984 bytes, checksum: 4ff93a7fe459a5a56e15da26b7a6dd45 (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Este trabalho apresenta uma metodologia composta de duas fases para resolver problemas de otimização com restrições usando uma estratégia multiobjetivo. Na primeira fase, o esforço concentra-se em encontrar, pelo menos, uma solução factível, descartando completamente a função objetivo. Na segunda fase, aborda-se o problema como biobjetivo, onde se busca a otimização da função objetivo original e maximizar o cumprimento das restrições. Na fase um propõe-se uma estratégia baseada na diminuição progressiva da tolerância de aceitação das restrições complexas para encontrar soluções factíveis. O desempenho do algoritmo é validado através de 11 casos testes bastantes conhecidos na literatura especializada. This work presents a two-phase framework for solving constrained optimization problems using a multi-objective strategy. In the first phase, the objective function is completely disregarded and entire search effort is directed toward finding a single feasible solution. In the second phase, the problem is treated as a bi-objective optimization problem, where the technique converts constrained optimization to a two-objective optimization: one is the original objective function; the other is the degree function violating the constraints. In the first phase a methodology based on progressive decrease of the tolerance of acceptance of complex constrains is proposed in order to find feasible solutions. The approach is tested on 11 well-know benchmark functions.

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Sarjoughian, Hessam Seyed 1959. "Intelligent agents and hierarchical constraint-driven diagnostic units for a teleoperated fluid handling laboratory." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277219.

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The purpose of this thesis is to study and develop intelligent agents for the forthcoming Space Station Freedom. Relevant intelligent capabilities, which are necessary in a semi-autonomous laboratory environment, are assumed to be built into a robot. An intelligent controller based on the DEVS formalism and the event-based approach is considered for an experiment. We shall discuss multiple model representations, where each model is tailored toward a specific purpose. Considering the necessity of diagnostic capabilities, we shall discuss the possibility of hierarchical diagnostic units for the Space Station. A high-level diagnostic unit is implemented on the basis of an artificial intelligence scheme and a hierarchy of diagnosers. This thesis also discusses the need for real-time diagnostic units and real-time data acquisition. We shall consider a constraint driven diagnostic unit which utilizes the time/cost (i.e., the actual associated cost or time in inquiring information necessary for a diagnosis process) criterion in an attempt to locate the cause(s) of failures.

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Barkat, Ullah Abu Saleh Shah Muhammad Engineering &amp Information Technology Australian Defence Force Academy UNSW. "An integrated evolutionary system for solving optimization problems." Awarded by:University of New South Wales - Australian Defence Force Academy. Engineering & Information Technology, 2009. http://handle.unsw.edu.au/1959.4/43764.

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Many real-world decision processes require solving optimization problems which may involve different types of constraints such as inequality and equality constraints. The hurdles in solving these Constrained Optimization Problems (COPs) arise from the challenge of searching a huge variable space in order to locate feasible points with acceptable solution quality. Over the last decades Evolutionary Algorithms (EAs) have brought a tremendous advancement in the area of computer science and optimization with their ability to solve various problems. However, EAs have inherent difficulty in dealing with constraints when solving COPs. This thesis presents a new Agent-based Memetic Algorithm (AMA) for solving COPs, where the agents have the ability to independently select a suitable Life Span Learning Process (LSLP) from a set of LSLPs. Each agent represents a candidate solution of the optimization problem and tries to improve its solution through cooperation with other agents. Evolutionary operators consist of only crossover and one of the self-adaptively selected LSLPs. The performance of the proposed algorithm is tested on benchmark problems, and the experimental results show convincing performance. The quality of individuals in the initial population influences the performance of evolutionary algorithms, especially when the feasible region of the constrained optimization problems is very tiny in comparison to the entire search space. This thesis proposes a method that improves the quality of randomly generated initial solutions by sacrificing very little in diversity of the population. The proposed Search Space Reduction Technique (SSRT) is tested using five different existing EAs, including AMA, by solving a number of state-of-the-art test problems and a real world case problem. The experimental results show SSRT improves the solution quality, and speeds up the performance of the algorithms. The handling of equality constraints has long been a difficult issue for evolutionary optimization methods, although several methods are available in the literature for handling functional constraints. In any optimization problems with equality constraints, to satisfy the condition of feasibility and optimality the solution points must lie on each and every equality constraint. This reduces the size of the feasible space and makes it difficult for EAs to locate feasible and optimal solutions. A new Equality Constraint Handling Technique (ECHT) is presented in this thesis, to enhance the performance of AMA in solving constrained optimization problems with equality constraints. The basic concept is to reach a point on the equality constraint from its current position by the selected individual solution and then explore on the constraint landscape. The technique is used as an agent learning process in AMA. The experimental results confirm the improved performance of the proposed algorithm. This thesis also proposes a Modified Genetic Algorithm (MGA) for solving COPs with equality constraints. After achieving inspiring performance in AMA when dealing with equality constraints, the new technique is used in the design of MGA. The experimental results show that the proposed algorithm overcomes the limitations of GA in solving COPs with equality constraints, and provides good quality solutions.

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Padrón, Astorga Silvia. "A multi-objective optimization approach to the ground handling scheduling problem." Doctoral thesis, Universitat Autònoma de Barcelona, 2014. http://hdl.handle.net/10803/284947.

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El tiempo de escala o turnaround es uno de los procesos aeroportuarios más críticos y se define como el período de tiempo en que la aeronave está en rampa, entre un vuelo de llegada y uno de salida. Durante el turnaround se realizan un conjunto de operaciones necesarias para preparar un avión para el próximo vuelo. Estas tareas son interdependientes y cada operación es una potencial fuente de demoras para el resto de las actividades, así como para otros procesos dentro del aeropuerto. Además, las decisiones de planificación que se toman para cada operación afectan la programación de otras tareas y el rendimiento de sus recursos. La falta de integración entre las diferentes operaciones y un uso ineficiente de los recursos durante el turnaround son causas importantes de retrasos en los vuelos. Esta tesis tiene como objetivo contribuir a la eficiencia de las operaciones de asistencia en tierra durante el turnaround, abordando el problema desde una perspectiva global. Con este fin se han considerado diferentes operaciones, así como las relaciones de precedencia entre estas, en lugar de programar cada actividad por separado. Se propone una aproximación multiobjetivo para realizar la planificación de los vehículos que dan servicio a las aeronaves en un aeropuerto durante un día. La solución al problema consiste en obtener un plan para estos vehículos que cumpla con las restricciones de tiempo, de precedencia y con las limitaciones de capacidad. Además de obtener una programación optimizada para cada actividad, es importante tener en cuenta el impacto que estas tienen en otras tareas. De esta manera, podemos integrar las decisiones realizadas para cada operación y contribuir a optimizar el proceso global. Dos objetivos han sido definidos con este fin: (I) minimizar el tiempo de espera para iniciar una operación y la reducción de las ventanas de tiempo disponibles, usando los vehículos eficientemente; y (II) minimizar el tiempo total de finalización del turnaround. Para resolver el problema multiobjetivo se ha desarrollado un nuevo método llamado Sequence Iterative Method (SIM) y se obtiene un rango de soluciones, las cuales representan el mejor compromiso entre los dos objetivos. Mediante un esquema de descomposición basado en Job Shop Scheduling Problem, el problema de optimización es desglosado. Este esquema proporciona un método consistente para resolverlo completo, simplificando el modelo y el proceso de resolución. En primer lugar, se calcula una ventana de tiempo para cada operación de acuerdo con las restricciones temporales y de precedencia. Un Vehicle Routing Problem with Time Windows (VRPTW) es identificado para cada tipo de vehículo involucrado, lo que da lugar a múltiples VRPTWs. Estos se resuelven de forma individual y las decisiones tomadas para cada problema de enrutamiento se propagan a los demás VRPTWs a través de reducciones en las ventanas de tiempo disponibles. Las principales funciones de la aproximación son modeladas e implementadas en Constraint Programming (CP). Además, CP se emplea en combinación con Variable Neighborhood Descent (VND) y Large Neighborhood Search (LNS) como metodología para resolver los VRPTWs. El conocido método Insertion Heuristic se utilizó para encontrar una primera solución de forma rápida, la cual se mejora posteriormente utilizando la metodología. Por último, una versión de la aproximación es propuesta con el objetivo de aplicar una exploración más exhaustiva para encontrar las soluciones de Pareto. En este caso, estas se obtienen mediante el método de Insertion Heuristic y solo las más prometedoras son mejoradas con la metodología. Se sugieren dos estrategias para determinar qué soluciones son las más prometedoras y estas reglas pueden ser también empleadas para finalmente seleccionar la mejor a implementar. Turnaround is one of the most critical airport processes. It is defined as the period of time the aircraft is on the ramp between an inbound and outbound flight, and different ground handling operations are performed. Ground handling comprises a set of interrelated services necessary to prepare an aircraft for the next flight. Since ground handling tasks are very interdependent, each operation is a potential source of delays which could be easily propagated to other operations and other airport processes. Moreover, planning decisions about each vehicle required to perform an operation affect the scheduling of other activities and the performance of other resources. The lack of integration of the different activities and an inefficient use of the resources during turnaround are important causes of flight delays. This thesis aims to contribute to the operational efficiency of ground handling facing the problem from a global perspective. Different operations and their interconnections have been considered instead of scheduling each activity in isolation. We introduce a multi-objective approach for scheduling the ground handling vehicles that perform this set of related activities. Solving this problem consists of obtaining a schedule for the vehicles that service aircraft at an airport during one working day. The schedule has to satisfy temporal, precedence, and capacity constraints. Besides obtaining optimized schedules for each activity, it is important to take into account the impact on other tasks. This way, we can integrate the scheduling decisions made for each service and contribute to optimize the overall ground handling process. Two objectives are defined in order to integrate the scheduling decisions : (i) minimizing the waiting time before an operation starts and the total reduction of the corresponding time windows, using the vehicles efficiently; and (ii) minimizing the total completion time of the turnarounds. A new method called Sequence Iterative Method (SIM) has been developed to address the multi-objective problem. With the aim to achieve a more flexible and accurate decision process, a range of solutions representing the best compromise between the two objectives is obtained. The ground handling problem is separated using a workcenter-based decomposition schema. This schema provides a consistent method to solve the complete problem and simplifies the model and the solution process. First, a planning problem is solved and a time window for each operation is calculated according to the temporal and precedence restrictions. One Vehicle Routing Problem with Time Windows (VRPTW) is identified for each type of vehicle involved, which leads to multiple VRPTWs. These are solved individually and decisions made on each routing problem are propagated to the other VRPTWs through reductions on the available time windows. The main features are modeled and implemented in Constraint Programming (CP). Furthermore, CP is used in combination with Variable Neighborhood Descent (VND) and Large Neighborhood Search (LNS) as a part of a hybrid methodology to solve each of the routing problems. The well-known Insertion Heuristics method has been applied to produce a quick first solution which is later improved using the methodology. Finally, a version of the approach is proposed with the goal to allow a more exhaustive exploration to find Pareto solutions. In this case, solutions are obtained using the Insertion Heuristic and just the most promising are improved by the methodology. Two strategies are suggested to determine which solutions are the most promising and these rules can be also employed to guide the decision maker towards the selection of the best schedule to implement.

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Bremer, Jörg [Verfasser], Michael [Akademischer Betreuer] Sonnenschein, Oliver [Akademischer Betreuer] Kramer, and Wolfgang [Akademischer Betreuer] Renz. "Constraint-Handling mit Supportvektor-Dekodern in der verteilten Optimierung / Jörg Bremer. Betreuer: Michael Sonnenschein ; Oliver Kramer ; Wolfgang Renz." Oldenburg : BIS der Universität Oldenburg, 2015. http://d-nb.info/106831222X/34.

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Bremer, Jörg [Verfasser], Michael Akademischer Betreuer] Sonnenschein, Oliver [Akademischer Betreuer] Kramer, and Wolfgang [Akademischer Betreuer] [Renz. "Constraint-Handling mit Supportvektor-Dekodern in der verteilten Optimierung / Jörg Bremer. Betreuer: Michael Sonnenschein ; Oliver Kramer ; Wolfgang Renz." Oldenburg : BIS der Universität Oldenburg, 2015. http://d-nb.info/106831222X/34.

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Bremer, Jörg [Verfasser], Michael [Akademischer Betreuer] Sonnenschein, Oliver Akademischer Betreuer] Kramer, and Wolfgang [Akademischer Betreuer] [Renz. "Constraint-Handling mit Supportvektor-Dekodern in der verteilten Optimierung / Jörg Bremer. Betreuer: Michael Sonnenschein ; Oliver Kramer ; Wolfgang Renz." Oldenburg : BIS der Universität Oldenburg, 2015. http://d-nb.info/106831222X/34.

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Vitorino, dos Santos Filho Jairson. "CHROME: a model-driven component-based rule engine." Universidade Federal de Pernambuco, 2009. https://repositorio.ufpe.br/handle/123456789/1638.

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Made available in DSpace on 2014-06-12T15:51:39Z (GMT). No. of bitstreams: 2 arquivo2757_1.pdf: 5759741 bytes, checksum: 8075c58c36a6d409b242f2a7873fb02f (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Vitorino dos Santos Filho, Jairson; Pierre Louis Robin, Jacques. CHROME: a model-driven component-based rule engine. 2009. Tese (Doutorado). Programa de Pós-Graduação em Ciência da Computação, Universidade Federal de Pernambuco, Recife, 2009.

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de, Siqueira Teles Fabrício. "Towards Model-Driven Engineering Constraint-Based Scheduling Applications." Universidade Federal de Pernambuco, 2008. https://repositorio.ufpe.br/handle/123456789/2348.

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Made available in DSpace on 2014-06-12T15:57:08Z (GMT). No. of bitstreams: 2 arquivo3142_1.pdf: 2136149 bytes, checksum: 9584d05181d7f6e862c757ce418c8701 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2008 de Siqueira Teles, Fabrício; Pierre Louis Robin, Jacques. Towards Model-Driven Engineering Constraint-Based Scheduling Applications. 2008. Dissertação (Mestrado). Programa de Pós-Graduação em Ciência da Computação, Universidade Federal de Pernambuco, Recife, 2008.

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Isaacs, Amitay Engineering &amp Information Technology Australian Defence Force Academy UNSW. "Development of optimization methods to solve computationally expensive problems." Awarded by:University of New South Wales - Australian Defence Force Academy. Engineering & Information Technology, 2009. http://handle.unsw.edu.au/1959.4/43758.

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Evolutionary algorithms (EAs) are population based heuristic optimization methods used to solve single and multi-objective optimization problems. They can simultaneously search multiple regions to find global optimum solutions. As EAs do not require gradient information for the search, they can be applied to optimization problems involving functions of real, integer, or discrete variables. One of the drawbacks of EAs is that they require evaluations of numerous candidate solutions for convergence. Most real life engineering design optimization problems involve highly nonlinear objective and constraint functions arising out of computationally expensive simulations. For such problems, the computation cost of optimization using EAs can become quite prohibitive. This has stimulated the research into improving the efficiency of EAs reported herein. In this thesis, two major improvements are suggested for EAs. The first improvement is the use of spatial surrogate models to replace the expensive simulations for the evaluation of candidate solutions, and other is a novel constraint handling technique. These modifications to EAs are tested on a number of numerical benchmarks and engineering examples using a fixed number of evaluations and the results are compared with basic EA. addition, the spatial surrogates are used in the truss design application. A generic framework for using spatial surrogate modeling, is proposed. Multiple types of surrogate models are used for better approximation performance and a prediction accuracy based validation is used to ensure that the approximations do not misguide the evolutionary search. Two EAs are proposed using spatial surrogate models for evaluation and evolution. For numerical benchmarks, the spatial surrogate assisted EAs obtain significantly better (even orders of magnitude better) results than EA and on an average 5-20% improvements in the objective value are observed for engineering examples. Most EAs use constraint handling schemes that prefer feasible solutions over infeasible solutions. In the proposed infeasibility driven evolutionary algorithm (IDEA), a few infeasible solutions are maintained in the population to augment the evolutionary search through the infeasible regions along with the feasible regions to accelerate convergence. The studies on single and multi-objective test problems demonstrate the faster convergence of IDEA over EA. In addition, the infeasible solutions in the population can be used for trade-off studies. Finally, discrete structures optimization (DSO) algorithm is proposed for sizing and topology optimization of trusses. In DSO, topology optimization and sizing optimization are separated to speed up the search for the optimum design. The optimum topology is identified using strain energy based material removal procedure. The topology optimization process correctly identifies the optimum topology for 2-D and 3-D trusses using less than 200 function evaluations. The sizing optimization is performed later to find the optimum cross-sectional areas of structural elements. In surrogate assisted DSO (SDSO), spatial surrogates are used to accelerate the sizing optimization. The truss designs obtained using SDSO are very close (within 7% of the weight) to the best reported in the literature using only a fraction of the function evaluations (less than 7%).

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Eggers, Andreas [Verfasser], Martin [Akademischer Betreuer] Fränzle, and Nacim [Akademischer Betreuer] Ramdani. "Direct handling of ordinary differential equations in constraint-solving-based analysis of hybrid systems / Andreas Eggers. Betreuer: Martin Fränzle ; Nacim Ramdani." Oldenburg : BIS der Universität Oldenburg, 2014. http://d-nb.info/1056999748/34.

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Le, Riche Rodolphe. "Optimisation globale de systèmes mécaniques." Habilitation à diriger des recherches, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2008. http://tel.archives-ouvertes.fr/tel-00476005.

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This manuscrit is a compact presentation of my research done between 1993 and 2008 and which concerns the global optimization of mechanical systems. General and specialized global optimization algorithms are presented. With respect to previously published work, an updated presentation of my work on composite optimization is given.

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Amouzgar, Kaveh. "Multi-objective optimization using Genetic Algorithms." Thesis, Högskolan i Jönköping, Tekniska Högskolan, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-19851.

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In this thesis, the basic principles and concepts of single and multi-objective Genetic Algorithms (GA) are reviewed. Two algorithms, one for single objective and the other for multi-objective problems, which are believed to be more efficient are described in details. The algorithms are coded with MATLAB and applied on several test functions. The results are compared with the existing solutions in literatures and shows promising results. Obtained pareto-fronts are exactly similar to the true pareto-fronts with a good spread of solution throughout the optimal region. Constraint handling techniques are studied and applied in the two algorithms. Constrained benchmarks are optimized and the outcomes show the ability of algorithm in maintaining solutions in the entire pareto-optimal region. In the end, a hybrid method based on the combination of the two algorithms is introduced and the performance is discussed. It is concluded that no significant strength is observed within the approach and more research is required on this topic. For further investigation on the performance of the proposed techniques, implementation on real-world engineering applications are recommended.

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Atamna, Asma. "Analysis of Randomized Adaptive Algorithms for Black-Box Continuous Constrained Optimization." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS010/document.

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On s'intéresse à l'étude d'algorithmes stochastiques pour l'optimisation numérique boîte-noire. Dans la première partie de cette thèse, on présente une méthodologie pour évaluer efficacement des stratégies d'adaptation du step-size dans le cas de l'optimisation boîte-noire sans contraintes. Le step-size est un paramètre important dans les algorithmes évolutionnaires tels que les stratégies d'évolution; il contrôle la diversité de la population et, de ce fait, joue un rôle déterminant dans la convergence de l'algorithme. On présente aussi les résultats empiriques de la comparaison de trois méthodes d'adaptation du step-size. Ces algorithmes sont testés sur le testbed BBOB (black-box optimization benchmarking) de la plateforme COCO (comparing continuous optimisers). Dans la deuxième partie de cette thèse, sont présentées nos contributions dans le domaine de l'optimisation boîte-noire avec contraintes. On analyse la convergence linéaire d'algorithmes stochastiques adaptatifs pour l'optimisation sous contraintes dans le cas de contraintes linéaires, gérées avec une approche Lagrangien augmenté adaptative. Pour ce faire, on étend l'analyse par chaines de Markov faite dans le cas d'optimisation sans contraintes au cas avec contraintes: pour chaque algorithme étudié, on exhibe une classe de fonctions pour laquelle il existe une chaine de Markov homogène telle que la stabilité de cette dernière implique la convergence linéaire de l'algorithme. La convergence linéaire est déduite en appliquant une loi des grands nombres pour les chaines de Markov, sous l'hypothèse de la stabilité. Dans notre cas, la stabilité est validée empiriquement We investigate various aspects of adaptive randomized (or stochastic) algorithms for both constrained and unconstrained black-box continuous optimization. The first part of this thesis focuses on step-size adaptation in unconstrained optimization. We first present a methodology for assessing efficiently a step-size adaptation mechanism that consists in testing a given algorithm on a minimal set of functions, each reflecting a particular difficulty that an efficient step-size adaptation algorithm should overcome. We then benchmark two step-size adaptation mechanisms on the well-known BBOB noiseless testbed and compare their performance to the one of the state-of-the-art evolution strategy (ES), CMA-ES, with cumulative step-size adaptation. In the second part of this thesis, we investigate linear convergence of a (1 + 1)-ES and a general step-size adaptive randomized algorithm on a linearly constrained optimization problem, where an adaptive augmented Lagrangian approach is used to handle the constraints. To that end, we extend the Markov chain approach used to analyze randomized algorithms for unconstrained optimization to the constrained case. We prove that when the augmented Lagrangian associated to the problem, centered at the optimum and the corresponding Lagrange multipliers, is positive homogeneous of degree 2, then for algorithms enjoying some invariance properties, there exists an underlying homogeneous Markov chain whose stability (typically positivity and Harris-recurrence) leads to linear convergence to both the optimum and the corresponding Lagrange multipliers. We deduce linear convergence under the aforementioned stability assumptions by applying a law of large numbers for Markov chains. We also present a general framework to design an augmented-Lagrangian-based adaptive randomized algorithm for constrained optimization, from an adaptive randomized algorithm for unconstrained optimization

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Wang, Fei [Verfasser], Wolfgang [Akademischer Betreuer] Reinhardt, and Anders [Akademischer Betreuer] Östman. "Handling Data Consistency through Spatial Data Integrity Rules in Constraint Decision Tables / Fei Wang. Universität der Bundeswehr München, Fakultät für Bauingenieur- und Vermessungswesen. Gutachter: Wolfgang Reinhardt ; Anders Östman. Betreuer: Wolfgang Reinhardt." Neubiberg : Universitätsbibliothek der Universität der Bundeswehr München, 2008. http://d-nb.info/1062723678/34.

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Vargas, Dênis Emanuel da Costa. "Um algoritmo de evolução diferencial com penalização adaptativa para otimização estrutural multiobjetivo." Universidade Federal de Juiz de Fora, 2015. https://repositorio.ufjf.br/jspui/handle/ufjf/418.

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Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-01-15T14:16:25Z No. of bitstreams: 1 denisemanueldacostavargas.pdf: 16589539 bytes, checksum: 44a0869db27ffd5f8254f85fb69ab78c (MD5) Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-01-25T17:40:31Z (GMT) No. of bitstreams: 1 denisemanueldacostavargas.pdf: 16589539 bytes, checksum: 44a0869db27ffd5f8254f85fb69ab78c (MD5) Made available in DSpace on 2016-01-25T17:40:31Z (GMT). No. of bitstreams: 1 denisemanueldacostavargas.pdf: 16589539 bytes, checksum: 44a0869db27ffd5f8254f85fb69ab78c (MD5) Previous issue date: 2015-11-05 CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Problemas de Otimização Multiobjetivo (POMs) com restrições são frequentes em diversas áreas das ciências e engenharia, entre elas a Otimização Estrutural (OE). Apesar da Evolução Diferencial (ED) ser uma metaheurística muito atraente na resolução de problemas do mundo real, há uma carência na literatura de discussões sobre o desempenho em POMs de OE. Na sua grande maioria os problemas de OE apresentam restrições. Nesta tese utiliza-se uma técnica para o tratamento de restrições chamada de APM (Adaptive Penalty Method) que tem histórico de bons resultados quando aplicada em problemas monobjetivo de OE. Pelo potencial da ED na resolução de problemas do mundo real e da técnica APM em OE, juntamente com a escassez de trabalhos envolvendo esses elementos em POMs de OE, essa tese apresenta um estudo de um algoritmo bem conhecido de ED acoplado à técnica APM nesses problemas. Experimentos computacionais considerando cenários sem e com inserção de informações de preferência do usuário foram realizados em problemas com variáveis continuas e discretas. Os resultados foram comparados aos encontrados na literatura, além dos obtidos pelo algoritmo que representa o estado da arte. Comparou-se também os resultados obtidos pelo mesmo algoritmo de ED adotado, porém sem ser acoplado à técnica APM, objetivando investigar sua influência no desempenho da combinação proposta. As vantagens e desvantagens do algoritmo proposto em cada cenário são apresentadas nessa tese, além de sugestões para trabalhos futuros. Multiobjective Optimization Problems (MOPs) with constraints are common in many areas of science and engineering, such as Structural Optimization (SO). In spite of Differential Evolution (DE) being a very attractive metaheuristic in real-world problems, no work was found assessing its performance in SO MOPs. Most OE problems have constraints. This thesis uses the constraint handling technique called Adaptive Penalty Method (APM) that has a history of good results when applied in monobjective problems of SO. Due to the potential of DE in solving real world problems and APM in SO problems, and also with the lack of studies involving these elements in SO MOPs, this work presents a study of a well-known DE algorithm coupled to the APM technique in these problems. Computational experiments considering scenarios with and without inclusion of user preference information were performed in problems with continuous and discrete variables. The results were compared with those in the literature, in addition to those obtained by the algorithm that represents the state of the art. They were also compared to the results obtained by the same DE algorithm adopted, but without the APM technique, aiming at investigating the influence of the APM technique in their performance. The advantages and disadvantages of the proposed algorithm in each scenario are presented in this research, as well as suggestions for future works.

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Espinouse, Marie-Laure. "Flowshop et extensions : chevauchement des tâches, indisponibilité des machines et système de transport." Université Joseph Fourier (Grenoble), 1998. http://www.theses.fr/1998GRE10247.

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L'objet de cette thèse est d'étudier des extensions du flowshop. Dans le modèle classique, la règle de précédence entre les opérations d'une même tâche est la suivante : une opération pour commencer doit attendre que l'opération précédente soit achevée. Dans les deux premières extensions, la règle de précédence autorise un chevauchement entre les opérations. Nous considérons deux modèles différents : un avec des durées opératoires constantes et un avec des durées opératoires variables. Nous étudions pour ces deux modèles l'optimalité des ordonnancements de permutation et pour le cas variable, nous caractérisons un placement optimal des tâches pour une permutation donnée. Dans la troisième extension, la capacité de stockage entre les machines dépend des pièces à stocker. Nous montrons qu'il n'existe pas de compromis entre l'ordonnancement optimal pour le mode sans attente et l'ordonnancement obtenu par l'algorithme de Johnson. Dans la quatrième extension, nous considérons que toutes les tâches doivent être placées selon les règles du flowshop sans-attente et des périodes d'indisponibilité des machines doivent être prises en compte. Nous démontrons, dans ce cadre, plusieurs résultats de complexité (en fonction des caractéristiques des tâches et des périodes d'indisponibilité). Dans la dernière extension, nous prenons en compte un délai de transport des pièces. Nous considérons la minimisation du nombre de chariots à utiliser pour le transport des pièces afin de respecter un plan de production donné. Pour résoudre ce problème, nous développons deux approches (une stratégie globale de routage et une procédure fondée sur des règles de priorité). Nous menons ensuite une étude numérique comparative de ces deux approches

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Lai, Po-wu, and 賴伯武. "Multi-Objective Evolutionary Algorithms with Constraints Handling Mechanism." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/10092241845851670716.

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碩士 世新大學 資訊管理學研究所(含碩專班) 95 Multi-Objective Optimization (MOO) have been recently used in different kinds of fields. In methods of solving optimal solutions, there are different from classical method and Evolutionary Algorithms (EAs). EAs mimics nature’s evolutionary principles to drive its search towards an optimal solution. The mostly past research of MOO problems often focus on a algorithm of non-constrained problems. However, there are so many constrained MOO problems in the real world, and the constrains mechanism usually adopt a penalty function. But the design of penalty function must introduce penalty parameter to fit different kinds of problems, that’s the most difficult and uncertain factor to handle it. Therefore, this research introduces two famous algorithms- MOPSO and MOEMO with a mechanism without additional parameter to handle constrained problems. We use performance indices for measuring results of different complex problems.

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Xie, Junyi. "Handling Resource Constraints and Scalability in Continuous Query Processing." Diss., 2007. http://hdl.handle.net/10161/455.

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Lin, Po-Jan, and 林博然. "Handling Constraints in Particle Swarm Optimization Using Digital Information Substitution." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/70873563524717519763.

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碩士 淡江大學 機械與機電工程學系碩士班 101 Partical Swarm Algorithm (PSA) naturally is a unconstrained biocomputational optimization. In recent publications, several indirect constraints treatments were proposed named constrained partical swarm optimization (CPSO).The present thesis simulates birds flock communication to develop the information substitution strategy in treating constraints. This approach can gradually convert the infeasible individual becomes the feasible individual by refering the information of globally effective individual. The presenting strategy can be categorized to a direct method of constraints handling. Another approach presented here in is a modification of non-dominating strategy. The idea is that all constraints are transformed to an additional single objective, then non-dominating sorting technique can be applied. At the end, pareto front will converge to zero value of additional objective. Illustrative numerical examples shows that the proposed two approaches of constraint handling are effective and reliable for engineering optimization. Microthermal actuator is broadly used in MEMS, it has large power output and is easy to manufacture. It can be adapted for grasping human cell, however the 35°C is the high temperature limit on the grasping point. This thesis provides the optimum structural design by using CPSO proposed in the thesis with the aid finite of element analysis ANSYS.

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Su, Yu-De, and 蘇育德. "Multiobjective Technique in Constraints Handling GA for Electro-Thermal Microactuator Optimization." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/97146683371583018574.

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碩士 淡江大學 機械與機電工程學系碩士班 99 The quantity of violation in constraints is simulated to the concept of gene pathological change in biological system. The violation of all constraints is transformed to an artificially second design objective required to be minimized simultaneously. Consequently, the original objective integrated with such artificial objective to construct a two-objective in design optimization problem. A unique Pareto point can be sequentially obtained in which the value of second objective will converge to zero. This thesis presents the complete numerical algorithm and process in dealing with such a genetic revolution based optimization method. Some illustrative problems are solved and compared with that in published papers. Another topic in this thesis is the development for the optimization of electro-thermal microactuator and the application using constrained GA presented in this thesis. The design objective is the maximization of the deflection on a working point that corporate with a upper temperature limitation. Four models of electro-thermal microactuator are explored. The first category contains three models of single hot arm: constant length model, constant width model, and variable length/width model. The fourth model is double hot-arm model. The structural material volume, design deflection, and temperature influence are primary study items. Each model has its own feature that can be applied on particular situation. The optimum operating voltage can be obtained during the proposed solution process. In general, double hot-arm model results in the largest expected displacement; however, it requires a larger amount material than other model.

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Wang, Hsiao Peng, and 王效鵬. "The Handling of Input, Output, and Constraints in the CY1 Drawing Toolkit." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/70209242707850780666.

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碩士 中原大學 資訊工程研究所 83 This thesis introduces Dt, a drawing toolkit in the CY1 programming environment. Dt is a class library written in C++ programming language, and runs on top of X Window System. Besides its powerful capability of graphical output, Dt supports a novel method, called behavior, to handle user inputs that occur "on" graphical objects. Using the notion of behavior, we can separate the look of an graphical object from its feel. Because of the build-in object-oriented approach, a graphical object is also an input handler, and servers as the fundamental unit of user input handling. A graphical object may have a close relation with other graphical objects. There may also be some relationships among graphical objects and application data structure that must be maintained. Maintaining that relations keeps the consistency between the application and presentation. It is a burden for a programmer to write a program to maintain these relations. Constraints are one of several techniques devised to handle it. Dt supports constraints. In this thesis, I will describe how to use constraint to maintain consistency among objects and how the constraint mechanism works in detail.

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Chen, Jiun-Yi, and 陳均宜. "On the Joint Replenishment Problem Considering Transportation Costs and Material Handling Capacity Constraints." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/98710353707176093505.

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碩士 國立交通大學 運輸與物流管理學系 101 The conventional Joint Replenishment Problem (JRP) considers the following cost terms: (1) major setup cost, (2) minor setup cost and (3) holding cost. This study focuses on the extension of the JRP by taking into account the container transportation cost and the capacity constraints of the material handling facilities. We formulate a mathematical model for the concerned problem. Also, we conduct theoretical analysis for the transportation cost with respect to the number of required containers and the value of the basic period. Our theoretical results facilitate in proposing a search procedure for seeking an optimal and feasible basic period for a given set of multipliers. By encoding the set of multipliers, we propose a genetic algorithm (GA) that incorporates with the proposed search procedure. Following our numerical experiments, we conclude that the proposed GA is an effective solution approach that obtains excellent solutions for the concerned JRP.

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Jhang, Bo-Kai, and 張博凱. "On the Optimal Zone Design and Joint Replenishment Prob-lem Considering Material Handling Capacity Constraints." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/n9av64.

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碩士 國立交通大學 運輸與物流管理學系 103 The joint replenishment problem (JRP) determines the replenishment cy-cle time and lot size of each item so as to minimize the total costs per unit time. In this study, we investigate a problem that combines the delivery zone-design problem for all demand sites/customers and the joint replenishment problem under the general-integer policy. Different from the conventional JRP, we consider that the material handling facility has a capacity limit. Therefore, for each delivery-zone, the mathematical model for the JRP problem is augmented with a set of capacity constraints. We formulate a mathematical model for the concerned problem, and conduct full theoretical analysis for the mathematical model. Our results facilitate in proposing a hybrid genetic algorithm (GA) that not only seeks for an optimal zone design, but also incorporates with a search procedure for solving the JRP with material-handling capacity constraints. Following our numerical experiments, we demonstrate that the proposed hybrid GA is an effective solution approach for solving the concerned problem.

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Bhatnagar, Shalabh. "Integration of V2V-AEB system with wearable cardiac monitoring system and reduction of V2V-AEB system time constraints." Thesis, 2017. https://doi.org/10.7912/C2VH3H.

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Indiana University-Purdue University Indianapolis (IUPUI) Autonomous Emergency Braking (AEB) system uses vehicle’s on-board sensors such as radar, LIDAR, camera, infrared, etc. to detect the potential collisions, alert the driver and make safety braking decision to avoid a potential collision. Its limitation is that it requires clear line-of-sight to detect what is in front of the vehicle. Whereas, in current V2V (vehicle-to-vehicle communication) systems, vehicles communicate with each other over a wireless network and share information about their states. Thus the safety of a V2V system is limited to the vehicles with communication capabilities. Our idea is to integrate the complementary capabilities of V2V and AEB systems together to overcome the limitations of V2V and AEB systems. In a V2V-AEB system, vehicles exchange data about the objects information detected by their onboard sensors along with their locations, speeds, and movements. The object information detected by a vehicle and the information received through the V2V network is processed by the AEB system of the subject vehicle. If there is an imminent crash, the AEB system alerts the driver or applies the brake automatically in critical conditions to prevent the collision. To make V2V-AEB system advance, we have developed an intelligent heart Monitoring system and integrated it with the V2V-AEB system of the vehicle. The advancement of wearable and implantable sensors enables them to communicate driver’s health conditions with PC’s and handheld devices. Part of this thesis work concentrates on monitoring the driver’s heart status in real time by using fitness tracker. In the case of a critical health condition such as the cardiac arrest of a driver, the system informs the vehicle to take an appropriate operation decision and broadcast emergency messages over the V2V network. Thus making other vehicles and emergency services aware of the emergency condition, which can help a driver to get immediate medical attention and prevent accident casualties. To ensure that the effectiveness of the V2V-AEB system is not reduced by a time delay, it is necessary to study the effect of delay thoroughly and to handle them properly. One common practice to control the delayed vehicle trajectory information is to extrapolate trajectory to the current time. We have put forward a dynamic system that can help to reduce the effect of delay in different environments without extrapolating trajectory of the pedestrian. This method dynamically controls the AEB start braking time according to the estimated delay time in the scenario. This thesis also addresses the problem of communication overload caused by V2V-AEB system. If there are n vehicles in a V2V network and each vehicle detects m objects, the message density in the V2V network will be n*m. Processing these many messages by the receiving vehicle will take considerable computation power and cause a delay in making the braking decision. To prevent flooding of messages in V2V-AEB system, some approaches are suggested to reduce the number of messages in the V2V network that include not sending information of objects that do not cause a potential collision and grouping the object information in messages.

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Woldesenbet, Yonas Gebre. "Uncertainty and constraint handling in evolutionary algorithms." 2007. http://digital.library.okstate.edu/etd/umi-okstate-1018.pdf.

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Lin, Yi-Jun, and 林怡君. "Constraint Handling and Kriging for Multi-objective simulation optimization." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/49463747565809078376.

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碩士 國立高雄第一科技大學 運籌管理所 97 Evolutionary algorithms have been extensively used and quite effective to solve multi-objective optimization problems. However, integrating the multi-objective evolutionary algorithm with simulation optimization problems will expensive very much computation time for evaluating the objective functions and searching promising solutions. They not only require running many generations to approximate true Pareto-optimal front but also require long simulation time to reduce sampling errors. Our goal is to save computation time while maintaining the performance of the algorithm. First, this research proposes using a filtering mechanism Kriging in the multi-objective evolutionary c in order to save the computation time. After generating offspring solutions, we will forecast the objective functions of each offspring and filter out unpromising offspring solutions. Second, we focusing on constraint handling method to select and utilize solutions that slightly violate performance constraints, then we allow that to generate offspring solutions and find out closer to the efficiency frontier solutions. Finally, we also employ a two-stage procedure in algorithms. We apply pair t-test and confidence interval to save computation time and think about the simulation errors. This research also applies the algorithms in mathematics and simulation multi-objective optimization problems. Experimental results show that the algorithm with Kriging and constraint handling has very good convergence performance. And using the filtering mechanism can save simulation time without degrading the quality of non-dominated solutions. Two-stage procedure can save simulation time and screens out noncompetitive solutions.

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Der, Horng Lih, and 洪立德. "Research on Constraint Handling for Structural Optimization with Genetic Algorithms." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/14116804159020558835.

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碩士 國立臺灣大學 機械工程學研究所 87 This thesis studies the effect of constraint handling for structural optimization with genetic algorithms. First, a new form of the traditional exterior penalty function method with different penalty levels are introduced. The convergent characteristics of this new penalty function are investigated and compared with characteristics of the adaptive penalty function method and non-stationary penalty function method. Then, an evaluation process that can dynamically adjust the level of the penalty term is provided. This evaluation process determines the penalty level according to the violated constraint numbers and the level of constraint violation in the population. Finally, an integrated program combining genetic search algorithms and the ANSYS finite element software is developed. With this developed program, design processes of some test examples and practical structural design problems are given. From these results, it shows that the dynamic penalty level determined by the proposed evaluation process will give quite satisfactory convergent result for most cases.

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