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Tautenhahn, Ulrich, Uno Hämarik, Bernd Hofmann, and Yuanyuan Shao. "Conditional stability estimates for ill-posed PDE problems by using interpolation." Universitätsbibliothek Chemnitz, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-72654.
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The focus of this paper is on conditional stability estimates for ill-posed inverse problems in partial differential equations. Conditional stability estimates have been obtained in the literature by a couple different methods. In this paper we propose a method called interpolation method, which is based on interpolation in variable Hilbert scales. We are going to work out the theoretical background of this method and show that optimal conditional stability estimates are obtained. The capability of our method is illustrated by a comprehensive collection of different inverse and ill-posed PDE problems containing elliptic and parabolic problems, one source problem and the problem of analytic continuation.
2
Jones, Troy. "Working Through Problems: An Investigation of the Problems and Problem-Solving Approaches of Beginning Teachers." Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/28736.
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The purpose of the present investigation was to determine what professional and personal problems elementary-school teachers face during their initial years of teaching and how they cope with or solve these problems. Beginning teachers abandon the teaching profession at alarming rates causing grave financial burdens to school divisions, schools, and tax payers. The phenomenon has also contributed to the current teacher shortages in particular subject areas and certain geographic locations. Many teachers who left the profession before their fifth year of professional teaching reported the problems associated with teaching as primary reasons for their exodus. Qualitative in-depth interviews were conducted with six in-service elementary teachers. The interviews were conducted in three parts. All of the six participants were between their fifth and tenth year of teaching, and they all taught at the elementary level. The results indicated that they had problems with (a) personal issues and life experiences, (b) school curricula, (c) children with special needs, (d) differentiation of instruction, (e) discipline, (f) workload and time management, (g) parents, (h), student poverty and studentsâ home issues, (j) relationships with students, (k) teacher training, and (l) administration. The participants coped with these problems by using pattern matching indicating that their own life experiences and backgrounds had significant roles in their problem-solving processes. Recommendations are made for preservice and beginning in-service teachers to focus on their educational experiences and biographical information to recall relevant information that will help them to cope with and solve professional problems.<br>Ph. D.
3
Sneddon, Penny L. "Sleep Problems in Young Children With and Without Behavior Problems." DigitalCommons@USU, 2007. https://digitalcommons.usu.edu/etd/6127.
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There are numernus social, emotional, and behavioral problems toddlers and preschool children can exhibit. Some of the more common problems reported by parents of young children are daytime behavior problems and sleep disturbances. This study investigated sleep difficulties in toddler and preschool-age children with (n = 31) and without (n = 59) significant behavior problems. Furthermore, the current study investigated the relationship between sleep difficulties and other psychological constructs (i.e., maternal general stress, maternal depression, and parenting stress), which might be related to sleep and behavior problems. Mothers of clinically referred children with behavior problems and nonclinically referred children without behavior problems completed measures regarding their children's sleep and behavior as well as their own general stress, parenting stress, and depressive symptomology.
Overall, children with behavior problems showed significantly more sleep difficulties than children without behavior problems. Specifically, when compared to children without behavior problems, children with behavior problems took more time to initiate sleep, showed increased bedtime resistance, had more night wakings, and had shorter sleep durations. Additionally, the results showed that other factors (i.e., maternal depression, family stress, parent-child relationship stress) likely contribute to and/or maintain sleep disturbances in children. The findings from this study suggest a complex relationship between childhood sleep, daytime externalizing behaviors, and maternal health. Potential clinical implications of these findings and future directions for research are discussed.
4
Ali, Ismail 1961. "Uniqueness of Positive Solutions for Elliptic Dirichlet Problems." Thesis, University of North Texas, 1990. https://digital.library.unt.edu/ark:/67531/metadc330654/.
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In this paper we consider the question of uniqueness of positive solutions for Dirichlet problems of the form - Δ u(x)= g(λ,u(x)) in B, u(x) = 0 on ϑB,
where A is the Laplace operator, B is the unit ball in RˆN, and A>0. We show that if g(λ,u)=uˆ(N+2)/(N-2) + λ, that is g has "critical growth", then large positive solutions are unique. We also prove uniqueness of large solutions when g(λ,u)=A f(u) with f(0) < 0, f "superlinear" and monotone. We use a number of methods from nonlinear functional analysis such as variational identities, Sturm comparison theorems and methods of order.
We also present a regularity result on linear elliptic equation where a coefficient has critical growth.
5
Queiroz, Thiago Alves de. "Algoritmos para problemas de corte e empacotamento." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/275759.
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Orientador: Flávio Keidi Miyazawa<br>Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Computação<br>Made available in DSpace on 2018-08-18T01:07:44Z (GMT). No. of bitstreams: 1
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Previous issue date: 2010<br>Resumo: Problemas de Corte e Empacotamento são, em sua maioria, NP-difíceis e não existem algoritmos exatos de tempo polinomial para tais se for considerado P ¿ NP. Aplicações práticas envolvendo estes problemas incluem a alocação de recursos para computadores; o corte de chapas de ferro, de madeira, de vidro, de alumínio, peças em couro, etc.; a estocagem de objetos; e, o carregamento de objetos dentro de contêineres ou caminhões-baú. Nesta tese investigamos problemas de Corte e Empacotamento NP-difíceis, nas suas versões bi- e tridimensionais, considerando diversas restrições práticas impostas a tais, a saber: que permitem a rotação ortogonal dos itens; cujos cortes sejam feitos por uma guilhotina; cujos cortes sejam feitos por uma guilhotina respeitando um número máximo de estágios de corte; cujos cortes sejam não-guilhotinados; cujos itens tenham demanda (não) unitária; cujos recipientes tenham tamanhos diferentes; cujos itens sejam representados por polígonos convexos e não-convexos (formas irregulares); cujo empacotamento respeite critérios de estabilidade para corpos rígidos; cujo empacotamento satisfaça uma dada ordem de descarregamento; e, cujos empacotamentos intermediários e final tenham seu centro de gravidade dentro de uma região considerada "segura". Para estes problemas foram propostos algoritmos baseados em programação dinâmica; modelos de programação inteira; técnicas do tipo branch-and-cut; heurísticas, incluindo as baseadas na técnica de geração de colunas; e, meta-heurísticas como o GRASP. Resultados teóricos também foram obtidos. Provamos uma questão em aberto levantada na literatura sobre cortes não-guilhotinados restritos a um conjunto de pontos. Uma extensiva série de testes computacionais considerando instâncias reais e várias outras geradas de forma aleatória foram realizados com os algoritmos desenvolvidos. Os resultados computacionais, sendo alguns deles comparados com a literatura, comprovam a validade dos algoritmos propostos e a sua aplicabilidade prática para resolver os problemas investigados<br>Abstract: Several versions of Cutting and Packing problems are considered NP-hard and, if we consider that P ¿ NP, we do not have any exact polynomial algorithm for solve them. Practical applications arises for such problems and include: resources allocation for computers; cut of steel, wood, glass, aluminum, etc.; packing of objects; and, loading objects into containers and trucks. In this thesis we investigate Cutting and Packing problems that are NP-hard considering theirs two- and three-dimensional versions, and subject to several practical constraints, that are: that allows the items to be orthogonally rotated; whose cuts are guillotine type; whose cuts are guillotine type and performed in at most k stages; whose cuts are non-guillotine type; whose items have varying and unit demand; whose bins are of variable sizes; whose items are represented by convex and non-convex polygons (irregular shapes); whose packing must satisfy the conditions for static equilibrium of rigid bodies; whose packing must satisfy an order to unloading; and, whose intermediaries and resultant packing have theirs center of gravity inside a safety region; Such cutting and packing problems were solved by dynamic programming algorithms; integer linear programming models; branch-and-cut algorithms; several heuristics, including those ones based on column generation approaches, and metaheuristics like GRASP. Theoretical results were also provided, so a recent open question arised by literature about non-guillotine patterns restricted to a set of points was demonstrated. We performed an extensive series of computational experiments for algorithms developed considering several instances presented in literature and others generated at random. These results, some of them compared with the literature, validate the approaches proposed and suggest their applicability to deal with practical situations involving the problems here investigated<br>Doutorado<br>Doutor em Ciência da Computação
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Santos, Tânia Cerqueira. "Percepção de pais e educadoras sobre os problemas de externalização e internalização das crianças em idade pré-escolar." Master's thesis, [s.n.], 2011. http://hdl.handle.net/10284/1986.
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Dissertação de Mestrado apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Psicologia, especialização em Psicologia Clínica e da Saúde.<br>A presente investigação tem como objectivo descrever os problemas de
externalização e internalização aliandos à temática da parentalidade.
A fundamentação teórica é composta numa primeira fase pela perspectiva da
psicologia do desenvolvimento em idade pré-escolar, o contexto, organização e gestão
do jardim de infância. Os problemas de conduta e problemas emocionais integram o
segundo capítulo e por fim o tema da parentalidade.
Na elaboração do estudo empírico e recorrendo à literatura procedeu-se à criação
dos seguintes objectivos: (a) perceber se há diferenças na percepção acerca dos
comportamentos de internalização e externalização das crianças entre os pais e
educadoras (Lopes, 2002; Stivanin, Scheur & Assumpção Jr, 2008); (b) averiguar se
existem diferenças entre a escala total de problemas emocionais e a idade das crianças
(Oliveira, 2007); (c) entender se há diferenças entre os problemas de internalizção e
externalização dependendo do género da criança (Papalia, Olds & Feldman, 2001;
Stivanin, Scheuer & Assumpção Jr, 2008); (d) perceber se existem diferenças entre a
escala total dos problemas de externalização e a idade das crianças (Oliveira, 2007;
Papalia, Olds & Feldman, 2001; Silva, 2008).
Foi administrado o questionário SDQ – Questionário de capacidades e
dificuldades aos pais e educadoras de oitenta crianças em idade pré-escolar como forma
de conhecer as dificuldades e capacidades das crianças de acordo com os dois agentes
educativos.
Após a análise dos objectivos do estudo pode-se verificar os seguintes
resultados: (a) existem diferenças entre a percepção dos pais e educadoras relativamente
aos comportamentos das crianças; (b) os problemas de comportamento não variam de forma significativa em função da idade; (c) os problemas de internalização e
externalização não variam em função do género; (d) a idade das crianças não influencia
os problemas de externalização.
Mostra-se importante investir no estudo da problemática dos problemas de
conduta e problemas emocionais aliados à parentalidade como forma de melhorar a
“tarefa” de educar.---
This research was aimed to describe the problems of internalizing and
externalizing combined to the parenting thematic.
The theoretical basis is composed initially from the perspective of
developmental psychology at preschool age, context, organization and management of
the kindergarten. Conduct problems and emotional problems are part of the second
chapter and finally, the topic of parenting.
In developing the empirical study and using the literature, the following
objectives were established: (a) see if there are differences in children’s perception of
internalizing and externalizing behaviors between parents and educators (Lopes, 2002;
Stivanin, Scheur & Assumpção Jr, 2008); (b) see if there are differences between the
full range of emotional problems and the age of children (Oliveira, 2007); (c)
understand whether there are differences between the problems of internalizing and
externalizing depending on the gender of the child (Papalia, Olds & Feldman, 2001;
Stivanin, Scheuer & Assumpção Jr, 2008); (d) understand if there are differences
between the overall scale of externalizing problems and the age of children (Oliveira,
2007; Papalia, Olds & Feldman, 2001; Silva, 2008).
The SDQ – Strengths and Difficulties was administered to parents and educators
of eighty children in preschool as a way to understand the difficulties and abilities
according to both school staff.
After analyzing the objectives of the study, it is possible to verify the following
results: (a) there are differences between the perception of parents and educators in
relation to children’s behaviors; (b) behavior problems don’t vary significantly according to age; (c) internalizing and externalizing problems don’t vary according to
gender; (d) the child’s age doesn’t influence the problems of externalizing.
It reveals important to invest in the studying conduct and emotion problems
coupled with parenting as a way to improve the “task” of educating.
7
Yuen, Gary. "Problem solving strategies students use when solving combinatorial problems." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/5535.
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This research is a case study that examines the strategies that three grade 11 students use
to manoeuvre through a series of three combinatorial problems. Grade 11 students were chosen
as participants because they have had no formal training in solving this class of math problems.
Data includes video recordings of each participant’s problem solving sessions along with each
participant’s written work. Through analysis of this data, several themes related to problem
solving strategies were identified. First, students tend to rely on algebraic representation and
methods as they approach a problem. Second, students use the term “guess and check” to
describe any strategy where the steps to a solution are not clearly defined. Thirdly, as students
negotiate problems, they tend to search for patterns that will streamline their methods. Fourthly,
students approach complicated problems by breaking up the problem into smaller parts. Finally,
students who verify their work throughout the problems solving process tend to experience more
success than those who do not. From these findings, I suggest that mathematics teachers need to
ensure that they are not over-emphasizing algebraic strategies in the classroom. In addition,
students need to be given the opportunity to explore various solution strategies to a given
problem. Finally, students should be taught how to verify their work, and be encouraged to
perform this step throughout the problem solving process.
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8
Li, Zhi. "Progressing problems from requirements to specifications in problem frames." Thesis, Open University, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494245.
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Qiang, Feng. "Parallel problem generation for structured problems in mathematical programming." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/11688.
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The aim of this research is to investigate parallel problem generation for structured optimization problems. The result of this research has produced a novel parallel model generator tool, namely the Parallel Structured Model Generator (PSMG). PSMG adopts the model syntax from SML to attain backward compatibility for the models already written in SML [1]. Unlike the proof-of-concept implementation for SML in [2], PSMG does not depend on AMPL [3]. In this thesis, we firstly explain what a structured problem is using concrete real-world problems modelled in SML. Presenting those example models allows us to exhibit PSMG’s modelling syntax and techniques in detail. PSMG provides an easy to use framework for modelling large scale nested structured problems including multi-stage stochastic problems. PSMG can be used for modelling linear programming (LP), quadratic programming (QP), and nonlinear programming (NLP) problems. The second part of this thesis describes considerable thoughts on logical calling sequence and dependencies in parallel operation and algorithms in PSMG. We explain the design concept for PSMG’s solver interface. The interface follows a solver driven work assignment approach that allows the solver to decide how to distribute problem parts to processors in order to obtain better data locality and load balancing for solving problems in parallel. PSMG adopts a delayed constraint expansion design. This allows the memory allocation for computed entities to only happen on a process when it is necessary. The computed entities can be the set expansions of the indexing expressions associated with the variable, parameter and constraint declarations, or temporary values used for set and parameter constructions. We also illustrate algorithms that are important for delivering efficient implementation of PSMG, such as routines for partitioning constraints according to blocks and automatic differentiation algorithms for evaluating Jacobian and Hessian matrices and their corresponding sparsity partterns. Furthermore, PSMG implements a generic solver interface which can be linked with different structure exploiting optimization solvers such as decomposition or interior point based solvers. The work required for linking with PSMG’s solver interface is also discussed. Finally, we evaluate PSMG’s run-time performance and memory usage by generating structured problems with various sizes. The results from both serial and parallel executions are discussed. The benchmark results show that PSMG achieve good parallel efficiency on up to 96 processes. PSMG distributes memory usage among parallel processors which enables the generation of problems that are too large to be processed on a single node due to memory restriction.
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Del, Valle Aline Marques. "Problema da mochila com itens irregulares." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/275763.
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Orientador: Eduardo Candido Xavier<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Insituto de Computação<br>Made available in DSpace on 2018-08-17T16:49:45Z (GMT). No. of bitstreams: 1
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Previous issue date: 2010<br>Resumo: Nesta dissertação, estudamos problemas de empacotamento com itens irregulares. Estamos particularmente interessados no Problema da Mochila Bidimensional: dados um recipiente de tamanho W x H e uma lista de itens bidimensionais, o objetivo é empacotar um subconjunto dos itens de forma a maximizar a área dos itens empacotados. Existem diversos trabalhos que lidam com problemas para itens e recipientes bidimensionais com forma regular (retangular). No entanto, são poucos os estudos que tratam de itens com formas irregulares. Nós propomos algoritmos de empacotamento para itens irregulares em recipientes limitados baseados no uso de No-Fit-Polygon (NFP). Este trabalho apresenta uma heurística GRASP para a versão restrita do Problema da Mochila: uma solução inicial gulosa é gerada e, em seguida, utiliza-se um algoritmo de busca local para melhorar solução atual. Uma estratégia híbrida também foi proposta para versão irrestrita do Problema da Mochila. Ela divide-se em passos de empacotamento de itens irregulares e empacotamento de itens regulares. Testamos os algoritmos com instâncias adaptadas do problema de Strip Packing. O GRASP obteve empacotamentos ótimos para várias instancias testadas e, mesmo para as instâncias em que o algoritmo não obteve resultados ótimos, os empacotamentos obtidos tiveram boa taxa de ocupação, com valores relativamente próximos do ótimo. O tempo de execução do algoritmo foi razoável. Na estratégia híbrida, obtiveram-se empacotamentos bons para a maioria das instâncias, com taxa de ocupação acima de 90% e tempos de execução relativamente baixos<br>Abstract: In this work, we study packing problems dealing with two dimensional irregular items. We are particularly interested in the knapsack version of the problem: given a container with size W x H and a list of two dimensional items, the goal is to pack a subset of items such that the total area of packed items is maximized. There are several works that deal with problems for the case where items and containers have regular shapes (rectangular). However, only a few studies deal with items with irregular shapes. We propose algorithms for packing irregular items in limited containers based on the use of No-Fit-Polygon (NFP). This work presents a GRASP algorithm for the restricted version of the Knapsack Problem: first, a greedy initial solution is generated, then, the local search algorithm is used to improve the current solution. A hybrid strategy has also been proposed for the unrestricted version of the Knapsack Problem. It is divided into steps of packing irregular items and packing regular items. We tested the algorithms using adapted instances for the Strip Packing problem. The GRASP algorithm achieved optimal packings for several of the tested instances, and, even for those that the algorithm did not, the obtained packings had a good occupancy rate, with values relatively close to the optimum. The runtime of the algorithm was reasonable. In the hybrid strategy, we obtained good packings for most of the instances, with occupancy rates above 90% and relatively low execution times<br>Mestrado<br>Teoria da Computação<br>Mestre em Ciência da Computação
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Dirsė, Laura. "13 - 16 m. paauglių, turinčių mišrių elgesio ir emocinių sutrikimų, internalių ir eksternalių problemų lygis ir įvairovė." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2007. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2007~D_20070816_165327-21109.
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Darbo tikslas - nustatyti 13 – 16 metų paauglių, turinčių mišrių elgesio ir emocinių sutrikimų, internalių ir eksternalių problemų lygį ir įvairovę. Tyrimo pradžioje keliama hipotezė, jog paaugliai, turintys mišrių elgesio ir emocinių sutrikimų, turi aukštesnį internalių bei aukštesnį eksternalių problemų lygį, nei tokių sutrikimų neturintys bendraamžiai. Tikslui pasiekti kėlėme šiuos uždavinius: įvertinti 13 - 16 metų paauglių, pasižyminčių mišriais elgesio ir emociniais sutrikimais, internalių bei eksternalių problemų lygį ir įvairovę. Palyginti 13 - 16 metų paauglių, turinčių mišrių elgesio ir emocinių sutrikimų, su tokio pat amžiaus paauglių, neturinčių emocinių sutrikimų, internalių ir eksternalių problemų lygį ir įvairovę. Palyginti 13 – 16 metų paauglių, turinčių mišrių elgesio ir emocinių sutrikimų, su tokio pat amžiaus paauglių, neturinčių emocinių sutrikimų, nerimo lygį ir įvairovę.
Tyrimas atliktas, taikant šias metodikas: Žmogaus piešinys: emocinių sutrikimų atrankos procedūra DAP : SPED ( Screening Procedure for Emotional Disturbance); T. M. Achenbacho (1991) klausimynus 11 -18 metų jaunuolio savęs vertinimo lapą (Youth Self – Report (YSR 11/18), 6 -18 metų vaiko elgesio tyrimo lapą (Child Behavior Checklist (CBCL 4/18), bei Daugiamatę vaikų nerimo skalę MASC ( Multidimensional Anxiety Scale for Children). Tyrime dalyvavo 92 13 -16 metų paaugliai, 52 – klinikinės grupės paaugliai, pasižymintys mišriomis elgesio ir emocinėmis problemomis, bei 40 –... [toliau žr. visą tekstą]<br>The aim of the work is to ascertain the level and variety of internal and external problems of 13 – 16 years teenagers having medley behavior and emotional problems. In the beginning of the research was raised hypothesis, that the level of behavior and emotional problems is elevated for teenagers having medley behavior and emotional problems, than for teenagers do not having these problems. In order to achieve the aim we have raised these main objectives: to evaluate the level and variety of internal and external problems of 13 – 16 years teenagers having medley behavior and emotional problems. To evaluate the level and variety of anxiety of 13 – 16 years teenagers having medley behavior and emotional problems.
The research was carried out applying these research methods: standardized questionnaire by Achenbach (1991) – Your Self –Report (YSR 11 / 18), Child Behavior Checklist (CBCL 4 / 18); standardized MASC - Multidimensional Anxiety Scale for Children and DAP : SPED Draw A Person : Screening Procedure for Emotional Disturbance. 92 13 -16 years teenagers participated in the research. 52 teenagers, having medley behavior and emotional problems and 40 teenagers do not having these problems. Participated in the research and 52 parents of teenagers, having medley behavior and emotional problems and 40 parents of teenagers, do not having these problems.
After the research we carried out, that teenagers, having medley behavior and emotional problems experience more... [to full text]
12
Nguyen, Thi Phong. "Direct and inverse solvers for scattering problems from locally perturbed infinite periodic layers." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLX004/document.
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Nous sommes intéressés dans cette thèse par l'analyse de la diffraction directe et inverse des ondes par des couches infinies périodiques localement perturbées à une fréquence fixe. Ce problème a des connexions avec le contrôle non destructif des structures périodiques telles que des structures photoniques, des fibres optiques, des réseaux, etc. Nous analysons d'abord le problème direct et établissons certaines conditions sur l'indice de réfraction pour lesquelles il n'existe pas de modes guidés. Ce type de résultat est important car il montre les cas pour lesquels les mesures peuvent être effectuées par exemple sur une couche au dessus de la structure périodique sans perdre des informations importantes dans la partie propagative de l'onde. Nous proposons ensuite une méthode numérique pour résoudre le problème de diffraction basée sur l'utilisation de la transformée de Floquet-Bloch dans les directions de périodicité. Nous discrétisons le problème de manière uniforme dans la variable de Floquet-Bloch et utilisons une méthode spectrale dans la discrétisation spatiale. La discrétisation en espace exploite une reformulation volumétrique du problème dans une cellule (équation intégrale de Lippmann-Schwinger) et une périodisation du noyau dans la direction perpendiculaire à la périodicité. Cette dernière transformation permet d'utiliser des techniques de type FFT pour accélérer le produit matrice-vecteur dans une méthode itérative pour résoudre le système linéaire. On aboutit à un système d'équations intégrales couplées (à cause de la perturbation locale) qui peuvent être résolues en utilisant une décomposition de Jacobi. L'analyse de la convergence est faite seulement dans le cas avec absorption et la validation numérique est réalisées sur des exemples 2D. Pour le problème inverse, nous étendons l'utilisation de trois méthodes d'échantillonnage pour résoudre le problème de la reconstruction de la géométrie du défaut à partir de la connaissance de données mutistatiques associées à des ondes incidentes planes en champ proche (c.à.d incluant certains modes évanescents). Nous analysons ces méthodes pour le problème semi-discrétisée dans la variable Floquet-Bloch. Nous proposons ensuite une nouvelle méthode d'imagerie capable de visualiser directement la géométrie du défaut sans savoir ni les propriétés physiques du milieux périodique, ni les propriétés physiques du défaut. Cette méthode que l'on appelle imagerie-différentielle est basée sur l'analyse des méthodes d'échantillonnage pour un seul mode de Floquet-Bloch et la relation avec les solutions de problèmes de transmission intérieurs d'un type nouveau. Les études théoriques sont corroborées par des expérimentations numériques sur des données synthétiques. Notre analyse est faite d'abord pour l'équation d'onde scalaire où le contraste est sur le terme d'ordre inférieur de l'opérateur de Helmholtz. Nous esquissons ensuite l'extension aux cas où la le contraste est également présent dans l'opérateur principal. Nous complémentons notre travail par deux résultats sur l'analyse du problème de diffraction pour des matériaux périodiques ayant des indices négatifs. Nous établissons en premier le caractère bien posé du problème en 2D dans le cas d'un contraste est égal à -1. Nous montrons également le caractère Fredholm de la formulation Lipmann-Schwinger du problème en utilisant l'approche de T-coercivité dans le cas d'un contraste différent de -1<br>We are interested in this thesis by the analysis of scattering and inverse scattering problems for locally perturbed periodic infinite layers at a fixed frequency. This problem has connexions with non destructive testings of periodic media like photonics structures, optical fibers, gratings, etc. We first analyze the forward scattering problem and establish some conditions under which there exist no guided modes. This type of conditions is important as it shows that measurements can be done on a layer above the structure without loosing substantial informations in the propagative part of the wave. We then propose a numerical method that solves the direct scattering problem based on Floquet-Bloch transform in the periodicity directions of the background media. We discretize the problem uniformly in the Floquet-Bloch variable and use a spectral method in the space variable. The discretization in space exploits a volumetric reformulation of the problem in a cell (Lippmann-Schwinger integral equation) and a periodization of the kernel in the direction orthogonal to the periodicity. The latter allows the use of FFT techniques to speed up Matrix-Vector product in an iterative to solve the linear system. One ends up with a system of coupled integral equations that can be solved using a Jacobi decomposition. The convergence analysis is done for the case with absorption and numerical validating results are conducted in 2D. For the inverse problem we extend the use of three sampling methods to solve the problem of retrieving the defect from the knowledge of mutistatic data associated with incident near field plane waves. We analyze these methods for the semi-discretized problem in the Floquet-Bloch variable. We then propose a new method capable of retrieving directly the defect without knowing either the background material properties nor the defect properties. This so-called differential-imaging functional that we propose is based on the analysis of sampling methods for a single Floquet-Bloch mode and the relation with solutions toso-called interior transmission problems. The theoretical investigations are corroborated with numerical experiments on synthetic data. Our analysis is done first for the scalar wave equation where the contrast is the lower order term of the Helmholtz operator. We then sketch the extension to the cases where the contrast is also present in the main operator. We complement our thesis with two results on the analysis of the scattering problem for periodic materials with negative indices. Weestablish the well posedness of the problem in 2D in the case of a contrast equals -1. We also show the Fredholm properties of the volume potential formulation of the problem using the T-coercivity approach in the case of a contrast different from -1
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Trammell, Eugene. "The effects of instruction in problem-solving strategies including reading word problems on student achievement in solving word problems." DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 1986. http://digitalcommons.auctr.edu/dissertations/1376.
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The purpose of the study was to determine if there was a significant difference between the traditional method and the experimental or structured method of instruction in word problem solving and translating them into almost word less sentences. Two groups of ninth graders in a general mathematics course on reading and solving word problems were selected for the study. At the beginning of the study a pre test for achievement differences was administered. The test results indicated there were no significant achievement differences between the groups when the test was initiated.
Word problem solving instruction was given to the experimental group, but the control group was allowed to ask. questions only for clarification of the problems which possibly enabled them to pick up ideas on how to analyze word problems during the questioning session. The treatment consisted of problems on how to find discounts, commission, interest and sales tax. The t statistic and a .05 level of significance were used. A posttest was administered to both groups after the treatment, and the findings of the test results indicated that there was no significant difference in achievement. Therefore, teaching the reading of word problems did not affect the experimental method more than the use of the conventional method. of data indicated that there was no significant differ ence in achievement between the two groups. It was suggested that because the control group was permitted to ask questions, students in that group may have learned how to analyze word problems during the questioning sessions.
It was recommended that there should be more inter action between students and teachers through questions and answers during word problem-solving instruction. Teaching word problem solving should begin early in the elementary school and sequentialized in the middle and high school. In-service teaching on word problem solv ing should be provided. Calculators should be used by students only after they have mastered the basics of arithmetic.
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Kojima, Kazuaki, and Kazuhisa Miwa. "A System that Generates Word Problems Using Problem Generation Episodes." INTELLIGENT MEDIA INTEGRATION NAGOYA UNIVERSITY / COE, 2005. http://hdl.handle.net/2237/10369.
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Neufeld, Janis Sebastian. "Problem specific heuristics for group scheduling problems in cellular manufacturing." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-207063.
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The group scheduling problem commonly arises in cellular manufacturing systems, where parts are grouped into part families. It is characterized by a sequencing task on two levels: on the one hand, a sequence of jobs within each part family has to be identified while, on the other hand, a family sequence has to be determined. In order to solve this NP-hard problem usually heuristic solution approaches are used. In this thesis different aspects of group scheduling are discussed and problem specific heuristics are developed to solve group scheduling problems efficiently. Thereby, particularly characteristic properties of flowshop group scheduling problems, such as the structure of a group schedule or missing operations, are identified and exploited. In a simulation study for job shop manufacturing cells several novel dispatching rules are analyzed. Furthermore, a comprehensive review of the existing group scheduling literature is presented, identifying fruitful directions for future research.
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Stadler, Sophia. "Child disruptive behaviour problems, problem perception and help-seeking behaviour." Master's thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/26942.
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Disruptive behaviour problems in early childhood are found to be associated with many negative long-term outcomes, such as antisocial behaviour, adolescent delinquency, and substance abuse (Kellam, Werthamer-Larsson & Dolan (1991), as cited in Butler, 2005:1). Even after adolescence this arises, for, as Vogel (2008:16) states the 'frequency of behavioural problems or challenging behaviour among the youth of today often predicts the size of our future prison population'. These findings clearly highlight the importance of early identification of behavioural problems, adequate preventative intervention (Butler, 2005:1) and the necessity for early intervention to prevent their continuity, since behaviour problems are found to worsen without treatment (Loeber, 1982, cited in Butler, 2005:1). The goal of this study is to gain an understanding of disruptive behaviour in primary school learners. To achieve this goal, the objectives of this are to explore the nature of child disruptive behaviour problems; to explore parents and teachers' problem perception of child disruptive behaviour; to explore the problem threshold of parents and teachers toward child disruptive behaviour; and to explore their help-seeking behaviour. The study's aim, therefore, is to better understand and gain more insight in child disruptive behaviour problems before a threshold is reached by parents and teachers and help is sought from social service professionals. The study uses an exploratory qualitative research design to gain insight into child disruptive behaviour problems, problem perceptions and help-seeking behaviour in the Southern Cape Karoo District in the Western Cape. Child disruptive behaviour patterns were analysed along a three-point continuum (from less severe - 'preventative'; to moderate - 'early intervention'; and most severe - 'statutory') based, on problem perceptions of parents, teachers and social service professionals. In addition, the present study examines parents and teachers' problem thresholds to identify help-seeking behaviour and sources. A purposive sampling technique was used to select the participants according to appropriation and availability. Parents and teachers were contacted to participate voluntarily in the research from schools in the area - Acacia Primary School, Baartmansfontein Primary School, Buffelsriver Private Primary School and Matjiesfontein Primary School. The social service professionals who participated consisted of social workers, social auxiliary workers and police officials from the Department of Social Development, Child Welfare SA and the South African Police Service. The study consisted of a broad range of child ages and parental ages. Parent participants also included biological and foster parents. Data was gathered by means of a semi-structured interview schedule administered during 24 individual interviews. The schedule is based on information obtained from the literature review relevant to the models and theories selected. Previous research done by Jessica Hankinson in 2009 in America on child psychopathology, parental problem perception, and help-seeking behaviours was used as a reference for creating the data collection tool, since she also focused on child behavioural problems and used similar models in the theories. This tool was created in such a way as to be relevant to the South African context. The findings confirmed the serious nature of child disruptive behaviour amongst primary school learners, including abusive behaviour, assault, bullying, fighting, swearing, theft, criminal involvement, substance abuse, truancy and school dropouts. The participants were found to be able to perceive their child's problem behaviour and to perceive themselves to be competent parents in dealing with disruptive behaviour. Child disruptive behaviour was found to have a significant effect on classroom learning. Despite legislation banning this, the participants still resort to punitive corrective measures. Stigma related to professional services and the privacy of the family are found to be very relevant in help-seeking efforts. This lead to the conclusion that child disruptive behaviour may become a normal and acceptable phenomenon, and thus leads to late reporting - and social services being contacted only as a last resort. The most important recommendation resulting from the study indicates that there is a need for prevention and early intervention services for child disruptive behaviour. This should address the escalation of the behaviour that later results in the need for statutory services. The study further indicates that various sectors (social workers, teachers, community structures and the departments) need to collaborate and form partnerships in order to enhance the early reporting of children in need and the accessibility and availability of services rendered in rural areas. This could enhance the early identification, reporting and service delivery in order to find problem resolutions.
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Preciso, Luca. "Perturbation Analysis of the Conformal Sewing Problem and Related Problems." Doctoral thesis, Università degli studi di Padova, 1998. http://hdl.handle.net/11577/3425905.
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In this dissertation, we develop two related problems in the nonlinear functional analysis. The first is the analyticity of the Cauchy singular integral in Schauder spaces which is motivated by the second problem, namely the perturbation analysis of the conformal sewing problem in Schauder and Roumieu spaces. In Chapter II, we consider the Cauchy singular integral
f (t)φ0 (t) f ◦ φ(−1) (ξ)
1 1
C[φ, f ]( · ) ≡ p. v. dt = p. v. dξ
2πi ∂D φ(t) − φ(·) 2πi φ ξ − φ(·)
where the oriented simple closed curve φ and the density function f are both defined on the counterclockwise oriented boundary ∂D of the plane unit disk D. Although the linear operator C[φ, ·], for a fixed φ, and the numerical computation of C[φ, f ] have been extensively studied for the last century, in view to several applications to integral equations and boundary value problems (cf. e.g. Muskhelishvili (1953) and Gakhov (1966)), the analysis of the nonlinear functional dependence of C[φ, f ] upon both its arguments seems to be a subject analyzed only more recently (see Introduction Ch. II). This new subject of research finds application in the nonlinear problems of perturbation nature which involve the Cauchy singular integral. In Chapter II we extend the analyticity result for the operator C[·, ·] of Coifman & Meyer (1983b) to a Schauder spaces setting. We assume that both φ and f belong to a Schauder space, say C∗m,α (∂D, C), of complex-valued function of class C m,α on ∂D, with m a positive natural number and α ∈ ]0, 1[. As it is well-known, under such conditions on φ and f , the function C[φ, f ](·) is also of class C m,α . By proving the unique solvability of a boundary value problem of elliptic nature in D and by applying Implicit Function Theorem to a suitable functional equation, we show the real analyticity of C[·, ·]. Then we show the complex analyticity of C[·, ·] and we compute all its differentials. This result of Lanza & Preciso (1998) will be applied in the second part of this dissertation and in another perturbation problem associated to a nonlinear integral equation (cf. Lanza & Rogosin (1997)). In Chapter III, we introduce the conformal sewing problem associated to a shift φ of ∂D, i.e. a homeomorphism of ∂D to itself. It consists in finding a pair of conformal functions (F, G) defined in D and C \ cl D, respectively, such that their continuous extensions to cl D e C \ D, Fe and G e respectively, satisfy Fe(φ(t)) = G(t) for all t ∈ ∂D. A simple normalization condition and well-known results ensure that the sewing problem associated to φ has a unique solution (F, G) and we denote by (F [·], G[·]) the pair of operators which maps φ to the trace on ∂D of such solution. The regularity properties of the operators F [φ] and G[φ] in spaces of regular functions can be used in the study of Teichmüller spaces, which constitute an important subject in geometric function theory (see Nag (1996)). Our aim is to find natural Banach spaces of regular functions where to obtain the analyticity of F [·] and G[·]. First we study the regularity of such operators in Schauder spaces C∗m,α (∂D, C), with m ≥ 1, α ∈ ]0, 1[. By using the classical integral equation approach to the sewing problem, we show that G[φ] and F [φ] = G[φ] ◦ φ(−1) belong to C∗m,α (∂D, C) when φ belongs to C∗m,α (∂D, C). In this setting, by using the analyticity of the Cauchy singular integral (cf. Ch. II) and by applying Implicit Function Theorem to a suitable integral equation, we show that G[·] extends to a complex analytic operator. Then we prove that this Schauder spaces setting is not sufficient in order to obtain an analytic extension of the operator F [·]. Indeed a natural assumption in order to have F [·] analytic, is that φ belongs to a space of real analytic functions of ∂D to C. In Chapter IV we introduce Banach spaces of real analytic functions, namely the Roumieu spaces associated to the differentiation operator. In this setting we show that G[·] and F [·] can be extended to complex analytic operators by employing the regularity results on the composition and on the inversion operator of Lanza (1994 and 1996b).
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Samaitienė, Rūta. "Rolando epilepsija sergančių vaikų EEG pakitimų, miego bei elgesio sutrikimų ir klinikinių charakteristikų sąsajos." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2013. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2013~D_20130919_161212-43923.
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Nors Rolando epilepsijai (RE) būdinga gerybinė eiga, dalis sergančiųjų turi miego bei elgesio problemų. Nuosekliai ištyrėme 75 RE sergančius bei 32 lyginamosios grupės nesergančius epilepsija pacientus. Grupės nesiskyrė pagal amžių ir lytį. Suskirstėme sergančiuosius RE į dvi grupes pagal priepuolių pasikartojimą per paskutinius 6 mėnesius. Elgesio sutrikimai buvo vertinami pasitelkiant CBCL (angl. Child Behavior Checklist) klausimyną, miego sutrikimai-pagal vaikų miego sutrikimų skalę (SDSC) (angl. Sleep Disturbance Scale for Children). Vertinome miego ir elgesio problemas bei jų sąsajas su klinikiniais, EEG duomenimis bei vizualinės-motorinės reakcijos laiko duomenimis. Bendradarbiaudami su Vilniaus universiteto Matematikos ir informatikos fakultetu rankiniu ir automatiniu būdu tyrėme pacientų EEG.
Tik tiems RE pacientams, kuriems buvo priepuolių per paskutinius 6 mėn., nustatėme patikimai aukštesnius SDSC klausimyno įverčius (padidintą mieguistumą, kvėpavimo sutrikimus miego metu, miego- budrumo ritmo sutrikimus, ilgesnę miego latenciją) bei patikimai aukštesnius CBCL klausimyno rodiklius (socialinių sunkumų, mąstymo sunkumų, dėmesio sunkumų, agresyvaus elgesio bei bendrų sunkumų skalių įverčius). Elgesio problemos buvo susiję su ilgesne epilepsijos trukme, sunkesniais ir dažnesniais priepuoliais, miego problemomis bei miego EEG pakitimais (>35/min pikų kiekiu bei pikų lokalizacija ir kitose nei centrotemporalinės srityse). Budrumo EEG nustatytas >17/min pikų kiekis buvo... [toliau žr. visą tekstą]<br>Although patients with benign Rolandic epilepsy (RE) exhibit a benign course of the disease, some of them display sleep and behavioural problems.
Seventy five patients with RE, aged 6–11 years, were included in this study. The patients were divided into two subgroups according to the presence of seizures over the preceding 6 months. The comparison group comprised 32 patients without epilepsy and with similar characteristics in terms of age and sex. All patients underwent evaluation of sleep (Sleep Disturbance Scale for Children) and behaviour (Lithuanian version of Child Behaviour Checklist). We examined the sleep and behavioural problems in correlation with the clinical data, EEG data, and simple visual-motor reaction time data. We automatically and manually analysed EEG in the collaboration with Vilnius University Faculty of Mathematics and Informatics.
Only patients who had had seizures over the preceding 6 months displayed significantly higher scores for sleep problems (disorders of excessive daytime sleepiness, disorders of sleep breathing, and disorders of sleep-wake transition, longer sleep onset latency), and behavioural problems (social problems, thought problems, attention problems, and aggressive behavior) than the patients of the comparison group. Behavioural problems were associated with the longer epilepsy duration, more frequent and more severe seizures, sleep problems and sleep EEG data (spike frequency >35/min and spike focus, spreading to the other than... [to full text]
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Lear, Jonathan. "Intersex : Problems of theory become problems in practice." Thesis, Linköping University, Centre for Applied Ethics, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-9061.
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<p>This paper discusses the medical treatment of intersex infants: children born with ambiguous genitalia, chromosomes, or hormones. The central thesis is that unnecessary surgery, defined as surgery that is not necessary to preserve the life or physical health of the infant, is unethical when performed on infants and should be postponed until the patient is able to participate in, and contribute to, the decision. Three lines of argument are presented: One based on the lack of clinical evidence supporting unnecessary surgery; one based on how unnecessary surgery limits the child’s future choices; and one based on how problematic notions of gender have resulted in problems in practice. Together and separately, the three arguments lead to the conclusion that performing unnecessary surgery on intersex infants is unethical, and wherever possible surgery should be delayed until the patient can participate in the decision.</p>
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Huang, Minyao. "Vagueness in language use : problems and pseudo-problems." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608010.
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Grohs, Jacob R. "Developing a Measure of Systems Thinking Competency." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/51996.
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Institutions of higher education often promise to graduate individuals capable not only of excelling in their area of expertise but also qualified as exceptional leaders and citizens. Yet, what are the competencies needed from leaders in order to address the most challenging issues facing society? How would higher education cultivate the next generation of leaders for a world of problems we currently cannot solve, and how would it be determined if some graduates were 'more prepared' than others to face these challenges?
This dissertation seeks to answer these questions through the work of two distinct manuscripts. The first argues that human processes for meaning-making play critical formative roles in the setting and solving of our most complex problems. In essence, that problem-solving can be considered as embodied acts of meaning-making. This link is made through analysis of Bruner's concept of narrative and highlights the importance played by naming and framing through one's unique perspective while attempting to interpret an ill-structured problem.
The second manuscript develops a tool to measure 'systems thinking,' a competency that describes the sort of cognitive flexibility that might be beneficial for graduates to be emerging leaders capable of addressing critical societal issues. A framework for considering systems thinking competency is presented and used as the foundation of a scenario-based assessment tool. Results from a qualitative pilot study are shown as part of introducing the tool with primary findings: (a) the tool elicited meaningful data on each of the constructs for which it was designed; (b) emergent within each construct were possible means of characterizing the data that will allow for future study of variation across respondents.<br>Ph. D.
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Goulden, Emma. "A comparison of children's performance on problem analogies and analogy problems." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0024/MQ51347.pdf.
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Coleman, Elaine B. "Problem-solving differences between high and average performers on physics problems." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63961.
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Ruiz, Muñoz Juan Felipe. "The Problem of Formulating Design Problems : A Typology of Design Briefs." Licentiate thesis, Linköpings universitet, Företagsekonomi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-171558.
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It is common for a design team to be handed a problem to solve for others. The handing over is normally referred to as a ‘briefing’ process, and the documentation of the starting point and what is to be done is known as a ‘brief’. It is known that the way we frame and understand a problem influences what paths we see to potential solutions. The aim of this thesis is to understand what makes a good design brief and to do so in order to create an empirically informed, and theoretically underpinned, typology of design briefs and the kind of search processes they are disposed to induce. Different bodies of literature have tried to grasp how design solves problems in order to understand designer’s behavior and ultimately facilitate or improve it. Distinctions can, and have been made, between different kinds of problem formulations, as well as different problem-solving approaches. This thesis aims to integrate two previously distinct literatures, search process from the organizational perspective developed by James G. March, Herbert A. Simon, Richard Cyert and others and Design and the Design Process from the perspectives of authors such as Donald Schön, Kees Dorst and Nigel Cross among others, to propose a typology of design briefs in order to ultimately facilitate problem formulation and subsequently facilitate the design process. The simple and immediate answer to the question of what makes a good design brief is: ‘that depends’. It depends on the design process to be followed (if there is one), it depends on the kind of goals that should be achieved, the time available, and it also depends on how much and what is known about the problem and potential solutions. Based on this, four ideal types of design briefs are articulated, including the expected associated search behavior and challenges of design teams.<br>Det är vanligt att ett designteam får ett problem att lösa åt andra. Överlämnandet kallas normalt en ”briefing” -process och dokumentationen av utgångspunkten och vad som ska göras kallas ett ”design brief ”. Det är känt att det sätt vi ramar in och förstår ett problem påverkar vilka vägar vi ser till potentiella lösningar. Syftet med denna avhandling är att förstå vad som gör ett bra ”design brief ” och att göra det för att skapa en empiriskt informerad och teoretiskt underbyggd typologi av design brief och vilken typ av sökprocesser de uppmuntrar. Olika litteratur har försökt förstå hur design löser problem för att förstå designerns beteende och i slutändan underlätta eller förbättra det. Skillnader kan och har gjorts mellan olika typer av problemformuleringar och olika problemlösningsmetoder. Denna avhandling syftar till att integrera två tidigare distinkta litteraturområden, sökprocess ur det organisatoriska perspektivet som utvecklats av James G. March, Herbert A. Simon, Richard Cyert och andra samt Design och designprocessen ur perspektiv av författare som Donald Schön, Kees Dorst och Nigel Cross bland andra för att föreslå en typologi av design brief för att underlätta problemformulering och därmed också underlätta designprocessen. Det enkla och omedelbara svaret på frågan om vad som gör ett bra design brief är: ”det beror på”. Det beror på designprocessen som ska följas (om det finns en), det beror på vilken typ av mål som ska uppnås, den tillgängliga tiden, och det beror också på hur mycket och vad som är känt om problemet och potentiella lösningar. Baserat på detta artikuleras fyra idealtyper av design brief, inklusive det förväntade associerade sökbeteendet och utmaningar för designteam.<br><p>ISBN saknas i avhandlingen.</p>
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Li, Yaxian. "Lower bounds for integer programming problems." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/48959.
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Solving real world problems with mixed integer programming (MIP) involves efforts in modeling and efficient algorithms. To solve a minimization MIP problem, a lower bound is needed in a branch-and-bound algorithm to evaluate the quality of a feasible solution and to improve the efficiency of the algorithm. This thesis develops a new MIP model and studies algorithms for obtaining lower bounds for MIP.
The first part of the thesis is dedicated to a new production planning model with pricing decisions. To increase profit, a company can use pricing to influence its demand to increase revenue, decrease cost, or both. We present a model that uses pricing discounts to increase production and delivery flexibility, which helps to decrease costs. Although the revenue can be hurt by introducing pricing discounts, the total profit can be increased by properly choosing the discounts and production and delivery decisions. We further explore the idea with variations of the model and present the advantages of using flexibility to increase profit.
The second part of the thesis focuses on solving integer programming(IP) problems by improving lower bounds. Specifically, we consider obtaining lower bounds for the multi- dimensional knapsack problem (MKP). Because MKP lacks special structures, it allows us to consider general methods for obtaining lower bounds for IP, which includes various relaxation algorithms. A problem relaxation is achieved by either enlarging the feasible region, or decreasing the value of the objective function on the feasible region. In addition, dual algorithms can also be used to obtain lower bounds, which work directly on solving the dual problems.
We first present some characteristics of the value function of MKP and extend some properties from the knapsack problem to MKP. The properties of MKP allow some large scale problems to be reduced to smaller ones. In addition, the quality of corner relaxation bounds of MKP is considered. We explore conditions under which the corner relaxation is
tight for MKP, such that relaxing some of the constraints does not affect the quality of the lower bounds. To evaluate the overall tightness of the corner relaxation, we also show the worst-case gap of the corner relaxation for MKP.
To identify parameters that contribute the most to the hardness of MKP and further evaluate the quality of lower bounds obtained from various algorithms, we analyze the characteristics that impact the hardness of MKP with a series of computational tests and establish a testbed of instances for computational experiments in the thesis.
Next, we examine the lower bounds obtained from various relaxation algorithms com- putationally. We study methods of choosing constraints for relaxations that produce high- quality lower bounds. We use information obtained from linear relaxations to choose con- straints to relax. However, for many hard instances, choosing the right constraints can be challenging, due to the inaccuracy of the LP information. We thus develop a dual heuristic algorithm that explores various constraints to be used in relaxations in the Branch-and- Bound algorithm. The algorithm uses lower bounds obtained from surrogate relaxations to improve the LP bounds, where the relaxed constraints may vary for different nodes. We also examine adaptively controlling the parameters of the algorithm to improve the performance.
Finally, the thesis presents two problem-specific algorithms to obtain lower bounds for MKP: A subadditive lifting method is developed to construct subadditive dual solutions, which always provide valid lower bounds. In addition, since MKP can be reformulated as a shortest path problem, we present a shortest path algorithm that uses estimated distances by solving relaxations problems. The recursive structure of the graph is used to accelerate the algorithm. Computational results of the shortest path algorithm are given on the testbed instances.
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Silveira, Jefferson Luiz Moisés da 1986. "Algoritmos para problemas de empacotamento e roteamento." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/275605.
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Orientador: Eduardo Candido Xavier<br>Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Computação<br>Made available in DSpace on 2018-08-24T00:15:42Z (GMT). No. of bitstreams: 1
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Previous issue date: 2013<br>Resumo: Neste trabalho estamos interessados em problemas de empacotamento e roteamento. Assumindo a hipótese de que P ? NP, sabemos que não existem algoritmos eficientes para resolver tais problemas. Além de algoritmos exatos, duas das abordagens para resolver tais problemas são Algoritmos Aproximados e Heurísticas. Nesta tese mostramos algoritmos baseados nestas três abordagens para ambos os problemas, de empacotamento e roteamento. Os dois primeiros problemas atacados foram generalizações de problemas clássicos de empacotamento: O problema da mochila bidimensional e o problema de empacotamento em faixas. Estes foram generalizados adicionando restrições na forma de carregamento e descarregamento dos itens no recipiente (restrições estas, que aparecem no contexto de problemas de roteamento). O terceiro problema é uma combinação de problemas de empacotamento e roteamento. Neste caso, atacamos uma generalização do clássico Pickup and Delivery Problem. Propomos os primeiros resultados de aproximação para algumas versões dos problemas de empacotamento supracitados. Além disto, apresentamos algumas abordagens práticas para o terceiro problema. As heurísticas foram avaliadas através de experimentos computacionais comparando os seus resultados com algoritmos exatos<br>Abstract: In this work we are interested in packing and routing problems. Assuming P ? NP, we have that there are no efficient algorithms to deal with such problems. Besides exact algorithms, two approaches to solve such problems are Approximation Algorithms and Heuristics. In this thesis we show algorithms using these three approaches for both packing and routing problems. The first two addressed problems are generalizations of classical packing problems: The Two Dimensional Knapsack problem and the Strip Packing problem. These problems were generalized by adding constraints on the way the items can be inserted/removed into/from the bin (These constraints appear in the context of routing problems). The third problem is combination of packing and routing problems. It is a generalization of the classical Pickup and Delivery problem. We propose the first approximation results for some packing problems. Besides that, we present some practical algorithms for the third problem. The heuristics were assessed through computational experiments by comparing their results with exact algorithms<br>Doutorado<br>Ciência da Computação<br>Doutor em Ciência da Computação
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Cherri, Luiz Henrique. "Nesting problems." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/55/55134/tde-16112016-150256/.
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The two-dimensional irregular cutting and packing problems (aka nesting problems) have been studied over the past six decades and consist in cutting (packing) convex and non-convex small pieces from (in) large boards without overlapping. There are several variants of this problem that are defined according to the board shapes and the objective of each problem. There are a number of heuristics proposed in the literature to solve irregular cutting and packing problems, but only few mixed-integer programming models. Specifically, these models were developed for the irregular strip packing problem, that consists in packing pieces into a single board with fixed width and length to be minimized. For the other problem variants, there is no exact methods presented in the literature. The main difficulty in solving irregular cutting and packing problems is how to handle with the geometric constraints. These constraints depend on the type of placement of the pieces on the board that can be continuous or discrete. In this thesis, we present two mixed-integer programming models for the irregular strip packing problem in which the pieces can be continuously placed on the board. These models do not demand complex structures to be built. We also present a new dot data structure to store the information on the placement of the pieces and overlapping positions bringing flexibility and efficiency to discrete approaches. Using this structure, a matheuristic is proposed, combining the advantages of the models with discrete and continuous placement positions for the pieces on the board. Furthermore, constraint programming models for several variants of irregular cutting and packing problems are exploited. For some variants, these models are the first modelling representation. A new global constraint is developed to eliminate the overlap among pieces. Computational experiments were conducted to evaluate the developed approaches.<br>Os problemas de corte e empacotamento de peças irregulares bidimensionais vêm sendo estudados há décadas e consistem em cortar (empacotar) peças menores, convexas e não convexas, a partir de (em) placas maiores de forma a não se sobreporem. Existem diversas variantes deste problema, definidas de acordo com o formato da placa e objetivo de cada problema. Na literatura, muitas heurísticas foram propostas para a resolução dos problemas de corte e empacotamento de peças irregulares, porém, poucos modelos de programação inteira mista podem ser encontrados. Especificamente, estes modelos foram desenvolvidos para o problema de empacotamento em faixa, que consiste em empacotar as peças em uma placa de largura fixa e comprimento a ser minimizado. Para as demais variantes do problema, não existem métodos exatos propostos na literatura. A principal dificuldade na resolução dos problemas de corte e empacotamento de peças irregulares está na manipulação das restrições geométricas. Estas restrições dependem do tipo de posicionamento das peças na placa, que pode ser discreto ou contínuo. Nesta tese, apresentamos dois modelos de programação inteira mista para o problema de empacotamento de peças em faixa, no qual cada peça pode ser alocada de forma contínua na placa. Estes modelos não demandam estruturas complexas para serem construídos. Também apresentamos uma nova estrutura de dados para armazenar informações sobre o posicionamento das peças e as posições de sobreposição, trazendo flexibilidade e eficiência para abordagens discretas. Utilizando esta estrutura, uma matheuristica foi proposta, combinando as vantagens dos modelos com alocação discreta e contínua das peças na placa. Além disso, modelos de programação por restrições para diversas variantes dos problemas de corte e empacotamento de peças irregulares foram explorados. Para algumas variantes, estes modelos são a primeira representação via modelagem. Uma nova restrição global foi desenvolvida para eliminar a sobreposição entre as peças. Experimentos computacionais foram realizados para avaliar as abordagens propostas.
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Cherri, Luiz Henrique. "Nesting Problems." Doctoral thesis, Universidade de São Paulo, 2016. https://repositorio-aberto.up.pt/handle/10216/84291.
Pełny tekst źródłaStreszczenie:
The two-dimensional irregular cutting and packing problems (aka nesting problems) have been studied over the past six decades and consist in cutting (packing) convex and non-convex small pieces from (in) large boards without overlapping. There are several variants of this problem that are defined according to the board shapes and the objective of each problem. There are a number of heuristics proposed in the literature to solve irregular cutting and packing problems, but only few mixed-integer programming models. Specifically, these models were developed for the irregular strip packing problem, that consists in packing pieces into a single board with fixed width and length to be minimized. For the other problem variants, there is no exact methods presented in the literature. The main difficulty in solving irregular cutting and packing problems is how to handle with the geometric constraints. These constraints depend on the type of placement of the pieces on the board that can be continuous or discrete. In this thesis, we present two mixed-integer programming models for the irregular strip packing problem in which the pieces can be continuously placed on the board. These models do not demand complex structures to be built. We also present a new dot data structure to store the information on the placement of the pieces and overlapping positions bringing flexibility and efficiency to discrete approaches. Using this structure, a matheuristic is proposed, combining the advantages of the models with discrete and continuous placement positions for the pieces on the board. Furthermore, constraint programming models for several variants of irregular cutting and packing problems are exploited. For some variants, these models are the first modelling representation. A new global constraint is developed to eliminate the overlap among pieces. Computational experiments were conducted to evaluate the developed approaches.<br>Os problemas de corte e empacotamento de peças irregulares bidimensionais vêm sendo estudados há décadas e consistem em cortar (empacotar) peças menores, convexas e não convexas, a partir de (em) placas maiores de forma a não se sobreporem. Existem diversas variantes deste problema, definidas de acordo com o formato da placa e objetivo de cada problema. Na literatura, muitas heurísticas foram propostas para a resolução dos problemas de corte e empacotamento de peças irregulares, porém, poucos modelos de programação inteira mista podem ser encontrados. Especificamente, estes modelos foram desenvolvidos para o problema de empacotamento em faixa, que consiste em empacotar as peças em uma placa de largura fixa e comprimento a ser minimizado. Para as demais variantes do problema, não existem métodos exatos propostos na literatura. A principal dificuldade na resolução dos problemas de corte e empacotamento de peças irregulares está na manipulação das restrições geométricas. Estas restrições dependem do tipo de posicionamento das peças na placa, que pode ser discreto ou contínuo. Nesta tese, apresentamos dois modelos de programação inteira mista para o problema de empacotamento de peças em faixa, no qual cada peça pode ser alocada de forma contínua na placa. Estes modelos não demandam estruturas complexas para serem construídos. Também apresentamos uma nova estrutura de dados para armazenar informações sobre o posicionamento das peças e as posições de sobreposição, trazendo flexibilidade e eficiência para abordagens discretas. Utilizando esta estrutura, uma matheuristica foi proposta, combinando as vantagens dos modelos com alocação discreta e contínua das peças na placa. Além disso, modelos de programação por restrições para diversas variantes dos problemas de corte e empacotamento de peças irregulares foram explorados. Para algumas variantes, estes modelos são a primeira representação via modelagem. Uma nova restrição global foi desenvolvida para eliminar a sobreposição entre as peças. Experimentos computacionais foram realizados para avaliar as abordagens propostas.
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Ivakhnenko, O. "Environmental problems." Thesis, Sumy State University, 2017. http://essuir.sumdu.edu.ua/handle/123456789/65689.
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The planet Earth is only a tiny part of the universe, but it's the only place where human beings can live. Today, our planet is in serious danger. The poisoning of the world's land, air and water is the fastestspreading disease of civilization. If present trends continue for the next several decades, our planet will become uninhabitable.
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Золотова, Світлана Григорівна, Светлана Григорьевна Золотова, Svitlana Hryhorivna Zolotova, and M. S. Dodotchenko. "Ecological problems." Thesis, Видавництво СумДУ, 2010. http://essuir.sumdu.edu.ua/handle/123456789/17927.
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Seroshtan, J. V., and L. M. Chuchilina. "Ecological problems." Thesis, Видавництво СумДУ, 2008. http://essuir.sumdu.edu.ua/handle/123456789/16039.
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Samsonenko, L. U., and M. O. Sasyuk. "Environmental problems." Thesis, Sumy State University, 2014. http://essuir.sumdu.edu.ua/handle/123456789/45211.
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Environmental problems can be found in all areas of the world, and they affect land, water and air. Some of them result from what humans take from the environment, in the form of land for agriculture, and accommodation for a rapidly increasing population; mineral and fossil fuel resources; and timber. These problems include deforestation, erosion, damage to ecosystems and reductions in biodiversity. Other problems stem from what humans put into the environment, in the form of various pollutions. These issues include climate change, damage to the ozone layer, urban pollution, and acid rain.
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Obimpeh, M. O. "Environmental problems." Thesis, Видавництво СумДУ, 2004. http://essuir.sumdu.edu.ua/handle/123456789/23125.
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Solís, Baltodano Maria José. "Claims problems: An implementation approach." Doctoral thesis, Universitat Rovira i Virgili, 2018. http://hdl.handle.net/10803/663663.
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L'objectiu principal d'aquesta tesi es centra en els problemes de demanada. Un problema de conflicte d'interessos que surgeix en el moment en que un recurs s'ha de distribuir entre un cert nombre d'agents i no n'hi ha suficient per satisfer totes les seves demandes. El nostre objectiu principal és buscar solucions adequades i alternatives a aquest tipus de problemes. Partint d'aquesta base, estudiem dos problemes reals que representen aquest tipus de conflictes, el problema de pressupost públic de la sanitat a Catalunya i els fons estructurals de cohesió de la Unió Europea (UE). En el primer cas proposem una alternativa per distribuir el pressupost de salut de manera que es mantingui l'estabilitat de la comunitat. En el segon cas suggerim una forma de repartir el pressupost mitjançant les regles de repartiment i la imposició de garanties a cada una de les regions amb la finalitat de reduir la desigualtat i promoure de manera mes adequada la convergència.
Un altre dels nostres objectius és contribuir a aquesta teoria proporcionant, per una part (i) noves caracteritzacions per les dues regles més utilitzades en aquesta literatura, com són la regla igualitària en guanys (CEA, per les seves sigles en anglès) i la proposta d'Ibn Ezra, i per altre part (ii) proposant un nou model de problema de conflicte d'interessos, anomenat problema de reclamacions sequencials. A més redefinim la regles proporcional, la regla igualitaria en guanys (CEA), la regla igualitaria en pèrdues (CEL, per les seves sigles en anglès) i la regla del Talmud, amb la finalitat d'aconseguir caracteritzar-les a traves de l'ús dels exiomes estudiats en aquest camp.<br>El principal objetivo de esta tesis se centra en el enfoque teórico de los problemas de reclamaciones. Un problema de conflicto de intereses surge cuando hay un recurso insuficiente, que debe distribuirse entre un número agentes. Nuestro objetivo principal es buscar soluciones convenientes y alternativas a este tipo de problemas. Partiendo de este punto, estudiamos dos problemas reales que representan este tipo de conflicto, el problema de presupuesto público en sanidad en Cataluña y los fondos estructurales y de cohesión de la Unión Europea (UE). En el primer caso proponemos una alternativa para distribuir el presupuesto en salud con el fin de mantener la estabilidad de la comunidad. En el segundo caso sugerimos una manera alternativa de repartir el presupuesto a través de reglas de reparto y de la imposición de garantías a cada una de las regiones, con el fin de reducir la desigualdad y promover la convergencia de una manera más adecuada.
Además, otro propósito es poder contribuir esta teoría proporcionando (i) nuevas caracterizaciones para dos reglas comúnmente usadas en esta literatura, las cuales son regla de igual ganancias (CEA, por sus siglas en inglés), y la propuesta por Ibn Ezra (the Ibn Ezra proposal). (ii) Proponiendo un nuevo modelo de problema de conflicto de intereses, llamado problemas de reclamos secuenciales, además redefinimos las reglas, proporcional, de igual ganancias (CEA, por sus siglas en inglés), de igual perdidas (CEL, por sus siglas en inglés), y Talmud, con el fin de lograr caracterizarlas a través del uso de axiomas estudiados en este campo.<br>The main objective of this thesis is on claims problems. We look for suitable and alternative solutions to this kind of problems. From this point of view, we study two real problems that represent these conflicts, the first one is the problem of the public health budget in Catalonia and the second one is the structural and cohesion funds of the European Union (EU). In the first case, we propose an alternative way to distribute the health budget to maintain the stability of the community. In this case we look for a suitable solution using rules and some stability criteria’s. In the second case we suggest an alternative way to distribute the budget through claims rules and the imposition of guarantees to each one of the regions, with the aim to reduce inequality and promote convergence in a more appropriate way.
Additionally, another purpose is to be able to contribute to this theory by providing (i) new characterizations for two commonly used rules in this literature, which are the constrained equal awards rule (CEA), and the Ibn Ezra proposal, and (ii) propose a new model of claims problem, called sequential claims problems, in this sense we redefine the proportional, the constrained equal awards, the constrained equal losses and the Talmud rules, and characterize them through the use of axioms studied in this field.
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Dou, Lixin. "Procedures for basic inverse problems: Black body radiation problem and phonon density of states problem." Thesis, University of Ottawa (Canada), 1992. http://hdl.handle.net/10393/7544.
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Two numerical procedures, the regularization method and the maximum entropy method, have been investigated and developed to solve some basic inverse problems in theoretical physics. Both of them are applied to the inverse black body radiation problem and the inverse phonon density of states problem. The inverse black body radiation problem is concerned with the determination of the area temperature distribution of a black body source from spectral measurements of its radiation. The phonon density of states problem is defined to be the determination of the phonon density of states function from the measured lattice specific heat function at constant volume. Those problems are ill-posed and can be expressed as a Fredholm integral equation of the first kind. It appears that both the regularization method and the maximum entropy method are successful in solving the two ill-posed problems. Generally the two procedures can be applied to any inverse problem which belongs to the class of the Fredholm integral equation of the first kind.
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Martinsson, Linnea. "The Emergence Problems after The Combination Problem : Toward a solution of the problem of experience." Thesis, Umeå universitet, Institutionen för idé- och samhällsstudier, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-172776.
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Panpsychist and panprotopsychist views have become more prominent during the past years, greatlydue to Philip Goff, Galen Strawson, David Chalmers, William Seager and others. Panpsychism isthe view that fundamental entitites have phenomenal properties while panprotopsychism is the viewthat fundamental entities have the potential to realise consciousness under certain conditions, invirtue of their protophenomenal properties. My focus will be, particularly, on constitutive versionsof panpsychism, which entail the commitment to the constitutive grounding of ordinary subjects ofexperience in more fundamental phenomenal entities. More specifically, I will evaluate whethersolutions to its ”combination problems”, which theorise the combination or decombination offundamental entities, can be solutions of the problem of experience. Constitutive panpsychismattempts to avoid the emergence of consciousness altogether by postulating fundamental subjects,so that ordinary subjects should be explained exhaustively in terms of them. Emergentistpanpsychism, by contrast, is a form of intelligible, or non-brute, emergentism which considersordinary subjects to be something more than mere structure. However, I will argue that evenconstitutivism involves a type of emergence, compositional or individualizing emergence, whichmakes it collapse into emergentism. That also takes away its ability to solve the problem ofexperience through a combination problem. Furthermore, the problem of other minds puts epistemiclimitations on our abilities to solve combination problems, which makes it improbable, even ifconstitutivism could avoid subject emergence, that it would be possible to reach an objectivesolution to the problem of ordinary subjects of experience through combination. Also physicalism isa form of emergentism but involves the commitment of the brute emergence of phenomenalproperties from non-mental fundamental entitites. I will show that it too gains an emergenceproblem as a consequence of a small conceptual shift that causes its collapse intopanprotopsychism. By recognising that there are common emergence problems, if not aboutphenomenal properties in general then about ordinary subjects, physicalists and pan(proto)psychistscan continue consciousness research as a collected force. I will also be presenting versions ofemergentist panpsychism to exemplify views that already expect emergence problems andformulate questions for future research.
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Auxter, Abbey Auxter. "The Problem with Word Problems: An Exploratory Study of Factors Related to Word Problem Success." Diss., Temple University Libraries, 2016. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/392790.
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Math & Science Education<br>Ph.D.<br>College Algebra is a gatekeeper course that serves as an obstacle for many students pursuing STEM careers. Lack of success in this course could be a key reason why the United States lags behind other industrialized countries in the number of students graduating with STEM majors and joining the STEM workforce. Of the many topics presented in College Algebra that pose problems, students often have particular difficulty with the application of systems of equations in the form of word problems. The present study aims to identify the factors associated with success and failure on systems of equations word problems. The goal was to identify the factors that remained significant predictors of success in order to build a theory to explain why some students are successful and other have difficulty. Using the Opportunity-Propensity Model of Byrnes and colleagues as the theoretical guide (e.g., Byrnes & Miller-Cotto, 2016), the following questions set the groundwork for the current study: (1) To what extent do antecedent (gender, race/ethnicity, socioeconomic status, and university) and propensity factors (mathematical calculation ability, mathematics anxiety, self-regulation, motivation, and ESL) individually and collectively predict success with systems of equations word problems in College Algebra students, and (2) How do these factors relate to each other? Bivariate correlations and hierarchical multiple regression were used to examine the relationships between the factors and word problem set-up as well as correct completion of the word problems presented. Results indicated after all variables were entered, calculation ability, self-regulation as determined by homework score, and anxiety were the only factors to remain significant predictors of student performance on both levels. All other factors either failed to enter as significant predictors or dropped out when the complete set had been entered. Reasons for this pattern of results are discussed, as are suggestions for future research to confirm and extend these findings.<br>Temple University--Theses
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Rada, Miroslav. "Dvourozměrné řezné problémy." Master's thesis, Vysoká škola ekonomická v Praze, 2008. http://www.nusl.cz/ntk/nusl-4859.
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The thesis first addresses the typology of cutting problems and their relationship to the packing problems. These are categorized (Wascher et al (2005)) according to 5 basic kriteria into the so-called "refined problem types", which is the sufficiently detailed and practical segmentation of cutting problems. The thesis deals with a selected sample of some of the most interesting algorithms from the wide range of those used to solve the cutting problems. The Viswanathan-Bagchi algorithm for the exact solution of constrainted two-dimensional orthogonal Cutting stock probléme with gillotine cuts is briefly described. It enables to process a wide range of additional problem constraints. The body of the thesis concentrates on heuristic algorithms used to solve orthogonal Open dimension problems. The Best-fit algorithm according to Burke et al. (2004) is described in detail. The work introduces two modifications of this algorithm that helped improve the solution in 42 out of the 89 benchmark problems, while a worse solution was achieved only in 10 of them. Moreover, new and more effective data structures and procedures that enable to solve the testing exercise with approx 50 000 rectangles in just about 2,5 seconds have been introduced.
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Harutjunjan, G., and Bert-Wolfgang Schulze. "Conormal symbols of mixed elliptic problems with singular interfaces." Universität Potsdam, 2005. http://opus.kobv.de/ubp/volltexte/2009/2988/.
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Mixed elliptic problems are characterised by conditions that have a discontinuity on an interface of the boundary of codimension 1. The case of a smooth interface is treated in [3]; the investigation there refers to additional interface conditions and parametrices in standard Sobolev spaces. The present paper studies a necessary structure for the case of interfaces with conical singularities, namely, corner conormal symbols of such operators. These may be interpreted as families of mixed elliptic problems on a manifold with smooth interface. We mainly focus on second order operators and additional interface conditions that are holomorphic in an extra parameter. In particular, for the case of the Zaremba problem we explicitly obtain the number of potential conditions in this context. The inverses of conormal symbols are meromorphic families of pseudo-differential mixed problems referring to a smooth
interface. Pointwise they can be computed along the lines [3].
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Bain, Stuart, and n/a. "Evolving Algorithms for Over-Constrained and Satisfaction Problems." Griffith University. School of Information and Communication Technology, 2007. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20071126.080227.
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The notion that a universally effective problem solver may still exist, and is simply waiting to be found, is slowly being abandoned in the light of a growing body of work reporting on the narrow applicability of individual heuristics. As the formalism of the constraint satisfaction problem remains a popular choice for the representation of problems to be solved algorithmically, there exists an ongoing need for new algorithms to effciently handle the disparate range of problems that have been posed in this representation. Given the costs associated with manually applying human algorithm development and problem solving expertise, methods that can automatically adapt to the particular features of a specific class of problem have begun to attract more attention. Whilst a number of authors have developed adaptive systems, the field, and particularly with respect to their application to constraint satisfaction problems, has seen only limited discussion as to what features are desirable for an adaptive constraint system. This may well have been a limiting factor with previous implementations, which have exhibited only subsets of the five features identified in this work as important to the utility of an adaptive constraint satisfaction system. Whether an adaptive system exhibits these features depends on both the chosen represen-tation and the method of adaptation. In this thesis, a three-part representation for constraint algorithms is introduced, which defines an algorithm in terms of contention, preference and selection functions. An adaptive system based on genetic programming is presented that adapts constraint algorithms described using the mentioned three-part representation. This is believed to be the first use of standard genetic programming for learning constraint algo-rithms. Finally, to further demonstrate the efficacy of this adaptive system, its performance in learning specialised algorithms for hard, real-world problem instances is thoroughly evaluated. These instances include random as well as structured instances from known-hard benchmark distributions, industrial problems (specifically, SAT-translated planning and cryptographic problems) as well as over-constrained problem instances. The outcome of this evaluation is a set of new algorithms - valuable in their own right - specifically tailored to these problem classes. Partial results of this work have appeared in the following publications: [1] Stuart Bain, John Thornton, and Abdul Sattar (2004) Evolving algorithms for constraint satisfaction. In Proc. of the 2004 Congress on Evolutionary Computation, pages 265-272. [2] Stuart Bain, John Thornton, and Abdul Sattar (2004) Methods of automatic algorithm generation. In Proc. of the 9th Pacific Rim Conference on AI, pages 144-153. [3] Stuart Bain, John Thornton, and Abdul Sattar. (2005) A comparison of evolutionary methods for the discovery of local search heuristics. In Australian Conference on Artificial Intelligence: AI'05, pages 1068-1074. [4] Stuart Bain, John Thornton, and Abdul Sattar (2005) Evolving variable-ordering heuristics for constrained optimisation. In Principles and Practice of Constraint Programming: CP'05, pages 732-736.
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Cossio, Jorge Ivan. "Multiple solutions for semilinear elliptic boundary value problems." Thesis, University of North Texas, 1991. https://digital.library.unt.edu/ark:/67531/metadc332487/.
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In this paper results concerning a semilinear elliptic boundary value problem are proven. This problem has five solutions when the range of the derivative of the nonlinearity ƒ includes the first two eigenvalues. The existence and multiplicity or radially symmetric solutions under suitable conditions on the nonlinearity when Ω is a ball in R^N.
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Bain, Stuart. "Evolving Algorithms for Over-Constrained and Satisfaction Problems." Thesis, Griffith University, 2007. http://hdl.handle.net/10072/365848.
Pełny tekst źródłaStreszczenie:
The notion that a universally effective problem solver may still exist, and is simply waiting to be found, is slowly being abandoned in the light of a growing body of work reporting on the narrow applicability of individual heuristics. As the formalism of the constraint satisfaction problem remains a popular choice for the representation of problems to be solved algorithmically, there exists an ongoing need for new algorithms to effciently handle the disparate range of problems that have been posed in this representation. Given the costs associated with manually applying human algorithm development and problem solving expertise, methods that can automatically adapt to the particular features of a specific class of problem have begun to attract more attention. Whilst a number of authors have developed adaptive systems, the field, and particularly with respect to their application to constraint satisfaction problems, has seen only limited discussion as to what features are desirable for an adaptive constraint system. This may well have been a limiting factor with previous implementations, which have exhibited only subsets of the five features identified in this work as important to the utility of an adaptive constraint satisfaction system. Whether an adaptive system exhibits these features depends on both the chosen represen-tation and the method of adaptation. In this thesis, a three-part representation for constraint algorithms is introduced, which defines an algorithm in terms of contention, preference and selection functions. An adaptive system based on genetic programming is presented that adapts constraint algorithms described using the mentioned three-part representation. This is believed to be the first use of standard genetic programming for learning constraint algo-rithms. Finally, to further demonstrate the efficacy of this adaptive system, its performance in learning specialised algorithms for hard, real-world problem instances is thoroughly evaluated. These instances include random as well as structured instances from known-hard benchmark distributions, industrial problems (specifically, SAT-translated planning and cryptographic problems) as well as over-constrained problem instances. The outcome of this evaluation is a set of new algorithms - valuable in their own right - specifically tailored to these problem classes. Partial results of this work have appeared in the following publications: [1] Stuart Bain, John Thornton, and Abdul Sattar (2004) Evolving algorithms for constraint satisfaction. In Proc. of the 2004 Congress on Evolutionary Computation, pages 265-272. [2] Stuart Bain, John Thornton, and Abdul Sattar (2004) Methods of automatic algorithm generation. In Proc. of the 9th Pacific Rim Conference on AI, pages 144-153. [3] Stuart Bain, John Thornton, and Abdul Sattar. (2005) A comparison of evolutionary methods for the discovery of local search heuristics. In Australian Conference on Artificial Intelligence: AI'05, pages 1068-1074. [4] Stuart Bain, John Thornton, and Abdul Sattar (2005) Evolving variable-ordering heuristics for constrained optimisation. In Principles and Practice of Constraint Programming: CP'05, pages 732-736.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>School of Information and Communication Technology<br>Faculty of Engineering and Information Technology<br>Full Text
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Lafifi, Sohaib. "Vehicle routing problems with resources synchronization." Thesis, Compiègne, 2014. http://www.theses.fr/2014COMP1992.
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Cette thèse porte sur la résolution de problèmes de transport qui intègrent des contraintes temporelles considérant les fenêtres de temps, la synchronisation des visites et l’équilibrage des services. Ces problèmes trouvent plusieurs applications dans le monde réel.L’objectif de nos recherches est l’élaboration de nouvelles méthodes de résolution pour les problèmes considérés en examinant leur performance avec une étude comparative par rapport aux différentes approches de la littérature. Deux variantes sont traitées. Le premier cas étudie le Problème de Tournées de Véhicules avec Fenêtres de Temps (VRPTW). Nous proposons de nouveaux prétraitements et bornes inférieures pour déterminer le nombre de véhicules nécessaires en s’inspirant de travaux menés en ordonnancement (raisonnement énergétique) et d’autres problèmes combinatoires comme la clique maximum et les problèmes de bin-packing. Nous présentons également un algorithme d’optimisation par essaim particulaire qui traite de la minimisation du nombre de véhicules puis de celle du temps de trajet total. Le deuxième cas étudie le Problème de Tournées de Véhicules avec des Fenêtres de Temps et des Visites Synchronisées (VRPTWSyn). Nous proposons plusieurs méthodes basées sur des approches heuristiques et des formulations linéaires avec l’incorporation d’inégalités valides pour tenir compte de la contrainte de synchronisation<br>This dissertation focuses on vehicle routing problems, one of the major academic problems in logistics. We address NP-Hard problems that model some realworld situations particularly those with different temporal constraints including time windows, visit synchronization and service balance.The aim of this research is to develop new algorithms for the considered problems,investigate their performance and compare them with the literature approaches.Two cases are carried out. The first case studies the Vehicle Routing Problem with Time Windows (VRPTW). We propose new lower bound methods for the number of vehicles. Then we present a Particle Swarm Optimization algorithm dealing with the Solomon objective. The second case studies the VehicleRouting Problem with Time Windows and Synchronized Visits (VRPTWsyn).Both exact methods and heuristics are proposed and compared to the literature approaches
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Jaudženis, Rolandas. "Įstatymų ir kitų teisės aktų, reglamentuojančių asmenų, grįžusių iš įkalinimo įstaigų, socialinę integraciją, įgyvendinimas: Akmenės rajono pataisos inspekcijos atvejis." Bachelor's thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20100903_161250-75227.
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Bakalauro baigiamajame darbe nagrinėjamas įstatymų ir kitų teisės aktų, reglamentuojančių asmenų, grįžusių iš įkalinimo įstaigų, socialinę integraciją, įgyvendinimas Akmenės rajono pataisos inspekcijos atveju. Darbo teorinėje dalyje pateikiamos asmenų, grįžusių iš įkalinimo įstaigų, socialinės atskirties ir jų socialinės integracijos, bei įstatymų ir kitų teisės aktų, reglamentuojančių asmenų, grįžusių iš įkalinimo įstaigų, socialinę integraciją, sampratos, atskleidžiamas visuomenės ir valstybės vaidmuo sprendžiant asmenų, grįžusių iš įkalinimo įstaigų, socialinės integracijos problemas. Darbo tiriamojoje dalyje, naudojant dokumentų analizės, interviu ir veiklos savianalizės metodus, analizuojama Akmenės rajono pataisos inspekcijos veikla įgyvendinant įstatymus ir kitus teisės aktus, reglamentuojančius asmenų, grįžusių iš įkalinimo įstaigų, socialinę integraciją, išskiriamos problemos, bei pateikiami problemų sprendimo būdai.<br>Implementation of laws and other deeds regulating social integration of individuals released from imprisonment institutions taking the case of Correctional Inspectorate of Akmenė district is analyzed in Bachelor thesis. In theoretical part of the thesis the conceptions of social separation and social integration of individuals released from imprisonment institutions are presented together with conceptions of laws and other deeds, regulating social integration of individuals released from imprisonment institutions. The role of society and state in solving social integration issues of individuals released from imprisonment institutions is revealed. In the research part of the thesis the activities of Correctional Inspectorate of Akmenė district regarding implementation of laws and other deeds regulating social integration of individuals released from imprisonment institutions are analyzed by methods of document analysis, interviews and self-analysis of activities, identifying problems and suggesting solutions to the problems.
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Conley, Michele E. "UTILIZING TECHNOLOGY TO ENHANCE READING COMPREHENSION WITHIN MATHEMATICAL WORD PROBLEMS." CSUSB ScholarWorks, 2014. https://scholarworks.lib.csusb.edu/etd/121.
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Many students who are proficient with basic math facts struggle for understanding when it comes to word problems. Teachers time and time again teach and re-teach problem solving strategies in hope that their students will one day acquire all the skills necessary to become proficient in this area. Unfortunately understanding problem solving skills is not the only answer to solving word problems. There has been a significant amount of evidence linking reading comprehension to mathematical reasoning. The development of a website to assist teachers and students who are having difficulties with mathematical word problems is extremely beneficial. The website is designed with links, power points, and examples that enhance reading comprehension within mathematical word problems. Through this project, it has been determined that students who are exposed to an additional mathematical program related to breaking apart word problems show evidence of a greater understanding and mastery of solving mathematical word problems.
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Dias, Fábio Carlos Sousa. "Algoritmos para o problema de localização simples baseados nas formulações clássica e canônica." reponame:Repositório Institucional da UFC, 2008. http://www.repositorio.ufc.br/handle/riufc/17871.
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DIAS, Fábio Carlos Sousa. Algoritmos para o problema de localização simples baseados nas formulações clássica e canônica. 2008. 81 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências, Departamento de Computação, Fortaleza-CE, 2008.<br>Submitted by guaracy araujo (guaraa3355@gmail.com) on 2016-06-22T17:13:52Z
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Previous issue date: 2008<br>In this work, we study the Simple Plant Location Problem (SPLP). Using its classical mathematical programming formulation and another recently proposed formulation, we develop several algorithms to …nd lower and upper bounds for the problem as well as branch-and-bound algorithms. With the classical formulation, such bounds are obtained via the data correction method and dominance criteria between …xed and transportation costs. We propose a projection of this formulation that has shown to be computationally atractive. Using the new formulation, we propose and prove the correctness of several iterative procedures that attempt to …nd an optimal solution to the problem by solving a sequence of parametric sub-problems, each one obtained by removing some variables and constraints of the original formulation. At each iteration of this process, we can obtain lower and upper bounds. We also apply Lagrangean relaxation to this new formulation in order to get other bounds. We consider several possibilities of relaxing the constraints. In addition, we develop branch-and-bound algorithms based on both formulations and the obtained bounds. We evaluate the computational e¢ ciency of all proposed algorithms with hard test instances from the literature. Computational results are reported and comparisons with other algorithms from the literature are carried out.<br>Neste trabalho, estudamos o problema de localização simples (SPLP - Simple Plant Location Problem). Usando a formulação matemática clássica e uma outra formulação proposta recentemente, desenvolvemos vários algoritmos para encontrar limites inferiores e superiores, bem como algoritmos tipo branch-and-bound. Com a formulação clássica, tais limites são obtidos utilizando o método de correção de dados e critérios de dominância entre os custos …xos e de transporte. Propomos uma projeção dessa formulação, que se mostrou computacionalmente atrativa. Usando a nova formulação propomos e mostramos a corretude de vários procedimentos iterativos que procuram encontrar uma solução para o problema, resolvendo uma seqüência de subproblemas paramétricos obtidos com a remoção de variáveis e restrições da formulação original. Em cada iteração desse processo, podemos gerar limites inferiores e superiores. Aplicamos ainda relaxação lagrangeana a essa nova formulação para obter outros limites. Analisamos várias possibilidades de relaxação das restrições. Desenvolmento também algoritmos branch-and-bound baseados em ambas as formulações e nos limites obtidos. Avaliamos a e…ciência computacional de todos os algoritmos com instâncias de teste difíceis, disponíveis na literatura. Resultados computacionais e comparações com outros algoritmos da literatura são reportados.
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Dias, FÃbio Carlos Sousa. "Algoritmos para o problema de localizaÃÃo simples baseados nas formulaÃÃes clÃssica e canÃnica." Universidade Federal do CearÃ, 2008. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=2827.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico<br>Neste trabalho, estudamos o problema de localizaÃÃo simples (SPLP - Simple Plant Location Problem). Usando a formulaÃÃo matemÃtica clÃssica e uma outra formulaÃÃo proposta recentemente, desenvolvemos vÃrios algoritmos para encontrar limites inferiores e superiores, bem como algoritmos tipo branch-and-bound. Com a formulaÃÃo clÃssica, tais limites sÃo obtidos utilizando o mÃtodo de correÃÃo de dados e critÃrios de dominÃncia entre os custos …xos e de transporte. Propomos uma projeÃÃo dessa formulaÃÃo, que se mostrou computacionalmente atrativa. Usando a nova formulaÃÃo propomos e mostramos a corretude de vÃrios procedimentos iterativos que procuram encontrar uma soluÃÃo para o problema, resolvendo uma seqÃÃncia de subproblemas paramÃtricos obtidos com a remoÃÃo de variÃveis e restriÃÃes da formulaÃÃo original. Em cada iteraÃÃo desse processo, podemos gerar limites inferiores e superiores. Aplicamos ainda relaxaÃÃo lagrangeana a essa nova formulaÃÃo para obter outros limites. Analisamos vÃrias possibilidades de relaxaÃÃo das restriÃÃes. Desenvolmento tambÃm algoritmos branch-and-bound baseados em ambas as formulaÃÃes e nos limites obtidos. Avaliamos a e…ciÃncia computacional de todos os algoritmos com instÃncias de teste difÃceis, disponÃveis na literatura. Resultados computacionais e comparaÃÃes com outros algoritmos da literatura sÃo reportados.<br>In this work, we study the Simple Plant Location Problem (SPLP). Using its classical mathematical programming formulation and another recently proposed formulation, we develop several algorithms to …nd lower and upper bounds for the problem as well as branch-and-bound algorithms. With the classical formulation, such bounds are obtained via the data correction method and dominance criteria between …xed and transportation costs. We propose a projection of this formulation that has shown to be computationally atractive. Using the new formulation, we propose and prove the correctness of several iterative procedures that attempt to …nd an optimal solution to the problem by solving a sequence of parametric sub-problems, each one obtained by removing some variables and constraints of the original formulation. At each iteration of this process, we can obtain lower and upper bounds. We also apply Lagrangean relaxation to this new formulation in order to get other bounds. We consider several possibilities of relaxing the constraints. In addition, we develop branch-and-bound algorithms based on both formulations and the obtained bounds. We evaluate the computational e ciency of all proposed algorithms with hard test instances from the literature. Computational results are reported and comparisons with other algorithms from the literature are carried out.
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Zhao, Kun. "Initial-boundary value problems in fluid dynamics modeling." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31778.
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Thesis (Ph.D)--Mathematics, Georgia Institute of Technology, 2010.<br>Committee Chair: Pan, Ronghua; Committee Member: Chow, Shui-Nee; Committee Member: Dieci, Luca; Committee Member: Gangbo, Wilfrid; Committee Member: Yeung, Pui-Kuen. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Lafargue, Thomas. "Comportement de matériaux illuminés par des sources laser multi-kW." Electronic Thesis or Diss., Paris, HESAM, 2023. http://www.theses.fr/2023HESAE021.
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Résumé : Ce sujet de thèse se place dans le cadre d’un projet à moyen/long terme derecherche et développement d’armes laser de fortes puissances. En effet, suite à la diversificationdes menaces (cibles/modes opératoires) et aux risques futurs d’illuminationslaser, MBDA France, en coopération avec ALPhANOV, développe des essais autour d’unlaser continu haute puissance. L’objectif final de MBDA France est de pouvoir quantifierla vulnérabilité de cibles. Compte tenu de la variété des familles de matériaux d’intérêt,les mécanismes de dégradation intervenants dans ce type d’applications sont nombreux(fort couplage thermique, mécanique et chimique). De plus, ils sont peu documentés dufait de la rareté de moyens d’essais équipés de laser continu multi-kW. Le travail doctoralpermettront d’acquérir de la connaissance et de la compréhension de ces phénomènesd’interaction laser-matière grâce à des approches expérimentales et analyses numériques<br>This thesis subject is part of a medium/long-term project for the researchand development of high-power laser weapons. Indeed, following the diversification ofthreats (targets/operating modes) and the future risks of laser illuminations, MBDA France,in cooperation with ALPhANOV, is developing trials around a high-power continuouslaser. The final objective of MBDA France is to be able to quantify the vulnerability oftargets. Given the variety of families of materials of interest, the degradation mechanismsinvolved in this type of application are numerous (strong thermal, mechanical and chemicalcoupling). In addition, they are poorly documented due to the scarcity of test facilitiesequipped with multi-kW continuous lasers. The doctoral work will make it possible toacquire knowledge and understanding of these laser-matter interaction phenomena thanksto experimental approaches and numerical analyzes
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Leão, Aline Aparecida de Souza. "Geração de colunas para problemas de corte em duas fases." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/55/55134/tde-20052009-160448/.
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O Problema da Mochila Compartimentada é uma extensão do Problema da Mochila, em que os itens solicitados são divididos em classes, de modo que a mochila deve ser subdividida em compartimentos, os quais têm capacidades limitadas e são carregados com itens da mesma classe. Além disso, a construção de um compartimento tem um custo fixo e ocasiona uma perda no espaço da mochila. O objetivo consiste em maximizar a soma dos valores dos itens, descontado o custo fixo de inclusão de compartimentos. Neste trabalho, são abordados dois métodos de solução. A primeira abordagem é uma heurística, que consiste na combinação de duas heurísticas da literatura. A segunda abordagem é o método Geração de Colunas, que além de fornecer um novo limitante superior para o Problema da Mochila Compartimentada, ao final do método o problema mestre foi resolvido com as variáveis definidas como inteiras, obtendo uma solução factível. Em ambos os métodos, o modelo não-linear é decomposto em dois modelos lineares, no qual, um gera compartimentos e o outro os seleciona. Os resultados obtidos com as duas abordagens foram comparados com um limitante superior e se mostraram bastante satisfatórios<br>The Compartmentalized Knapsack Problem is an extension of the classical Knapsack Problem, where the ordered items are partitioned into classes, in such way that the knapsack must be divided into compartments, each one having limited capacity. In addition, the building of a compartment has a fixed cost and involves a loss of the overall capacity. The objective is to maximize the sum of the items utility value, minus the fixed costs of the compartments. This dissertation presents two solving methods. The first approach is a heuristic method, which is a combination of two heuristics from the literature. The second approach is a Column Generation method, that apart from it gives a new upper bound to the Compartmentalized Knapsack Problem, in the end of the method the master problem was solved with the variables defined as integer, that supplies a feasible solution. In both methods, the mathematical non linear model is decomposed into two linear models, one generates the compartments, and the other selects them to compose the knapsack. The results obtained with these two approaches were compared with an upper bound and they showed very efficient