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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Thinking in water : Brain size evolution in Cichlidae and Syngnathidae

Tsuboi, Masahito January 2015 (has links)
Brain size varies greatly among vertebrates. It has been proposed that the diversity of brain size is produced and maintained through a balance of adaptations to different types and levels of cognitive ability and constraints for adaptive evolution. Phylogenetic comparative studies have made major contributions to our understanding of brain size evolution. However, previous studies have nearly exclusively focused on mammalian and avian taxa and almost no attempts have been made to investigate brain size evolution in ectothermic vertebrates. In my thesis, I studied brain size evolution in two groups of fish with extreme diversity in ecology, morphology and life history, Cichlidae and Syngnathidae. Using phylogenetic comparative methods, I investigated four key questions in vertebrate brain size evolution; cognitive adaptation, sexual selection, phenotypic integration and energetic constraints. I have demonstrated i) that phenotypic integration can link functionally unrelated traits, and this may constrain independent evolution of each part involved or promote concerted evolution of an integrated whole, ii) that brain-body static allometry constrains the direction of brain size evolution, even though the static-allometry showed ability to evolve, allowing evolution of relative brain size under allometric constraints, iii) that the energetic constraints of development and maintenance of brain tissue is an important factor in forming the diversity in brain size in cichlids and syngnathids, both at macroevolutionary and microevolutionary time scales, and iv) that adaptation for feeding and female mating competition may have played key roles in the adaptive evolution of brain size in pipefishes and seahorses. To conclude, my thesis shows the strong benefit of using fish as a model system to study brain size evolution with a phylogenetic comparative framework.
2

Efeitos dos gastos pÃblicos sobre o desenvolvimento econÃmico dos municÃpios do Nordeste no perÃodo de 1991 - 2000 / Effect of the public expenses on the economic development of the cities northeast in the period of 1991 - 2000

Gustavo PicanÃo Dias 15 May 2007 (has links)
nÃo hà / Este trabalho tem por finalidade avaliar o comportamento das despesas sociais em relaÃÃo ao crescimento dos indicadores sociais nos municÃpios nordestinos no perÃodo de 1991- 2000. Para tanto, as variÃveis foram agrupadas em trÃs modelos. No primeiro modelo, como variÃvel dependente o IDH-M dos municÃpios foi comparado com os determinantes de despesas sociais, Produto Interno Bruto e orientaÃÃo partidÃria dos municÃpios analisados. No segundo, as variÃveis determinantes foram comparadas ao Ãndice de pobreza. Por Ãltimo, foi verificado o impacto destas variÃveis ao Ãndice GINI de desigualdade. De posse dos dados, foram realizadas estimaÃÃes economÃtrica para os 9 estados do nordeste. Os resultados obtidos mostram que: i) as despesas sociais, em geral, melhoram as condiÃÃes de vida da populaÃÃo; ii) hà uma forte influÃncia das despesas na reduÃÃo da pobreza; iii) os dispÃndios municipais elevam as desigualdades da populaÃÃo. / This work has the objective of evaluating the behavior of social expenses related to the rising of social indicators in northeastern cities in the period between 1991-2000.For that,the variables were put together in 3 different models .In the first model the dependent variable called IDH-M of those cities was compared to social expenses, the intern gross product and the political orientation of the researched cities. In the second one these variables were compared to the poverty index. And for last, it was verified the analysis of those variables to the GINI index of social unevenness. With all the data It was possible to make econometric estimative for the other 9 states of the northeast of Brazil. The obtained results showed that: i: The social expenses improve the life conditions of the population; ii: There is a strong influence of the expenses in the decrease of poverty; iii: The city expenses elevate the social gap.
3

The relationship between high-tech medical equipment and health service volume

Chang, Chia-Yi 17 January 2007 (has links)
The development and the utility of high-tech medical equipments are increasing relative to the health expenditure growth. These high-tech equipments do not necessary benefit the quality of patient care but increase the service utilization for hospitals. This study aims to describe the difference of equipments distribution between academic medical centers and metropolitan hospitals and to examine the association between the change of the kinds, number, and utility of high-tech medical equipments and the health service utilization. Two databases were used in this study. First, a secondary data from the annual hospital survey published in 2003 and 2004 by Taiwan Hospital Association was used. The data contained information on 8 health service volumes, kinds, number and utility of 17 kinds of high-tech medical equipments, 4 hospital characteristics, and 3 kinds of staff ratio. Second, Statistical Yearbook of Department of Social Affairs, Ministry of Interior provided data on Tthe percentage of 65+ years old population in every location. The 8 kinds of health service volumes varience were designed as dependent variables and the 3 independent variables were separately change of kinds, number and utility of high-tech medical equipments. There were 59 samples, 8 academic medical centers and 51 metropolitan hospitals, included. The t-test showed differences between academic medical centers and metropolitan hospitals in change of kinds, number, utility of high-tech medical equipments and health service volumes varience. Person correlation presented how these variables correlated to each other. Regression analyses predicted the health service utilization from those variables. Generally speaking, the academic medical centers only had significant higher varience of average daily emergency roomvisits¡]t = 3.59, p = 0.01¡^than metropolitan hospitals did but there was no significant difference in 3 independent variables. Besides, correlation among medical equipments, health service utilization and themselves shows that the change of total high-tech medical equipment kinds was significant positive correlated with the change of total number of high-tech medical equipments¡]r = 0.44¡^; the change of total number of high-tech medical equipment was significant positive correlated with average daily emergency roomvisits varience¡]r = 0.28¡^and average daily physical examination of outpatient department visits variance¡]r = 0.30¡^; the average utility of high-tech medical equipment was significant positive correlated with average daily outpatient department visits varience¡]r = 0.27¡^. However, the 3 independent variables have no overall significant effect on change of health service utilization. Based on the above findings, although literature indicated that the kinds and number of high-tech medical equipments somehow might stimulate the demand for health service, we did not find the same results. It could be concluded that hospitals¡¦ purchasing of equipment do not impose a significant impact on raising the medical service utilization. Thus, acquisition of high-tech medical equipment might make a hospital a technological leader or give the public a more professional image whether it can help a hospital raise the service quantity is still left to its management.
4

[en] EXPERIMENTAL STUDY OF CONJUNCTIVE QUERIES OPTIMIZATION WITH EXPENSIVE PREDICATES / [pt] ESTUDO EXPERIMENTAL DE ALGORITMOS PARA OTIMIZAÇÃO DE CONSULTAS CONJUNTIVAS COM PREDICADOS CAROS

RODRIGO SILVA GUARINO 12 July 2004 (has links)
[pt] As técnicas tradicionais de otimização de consultas em banco de dados possuem como heurística fundamental a organização dos predicados de uma consulta em dois tipos principais: predicados simples e predicados envolvendo junção(join) de tabelas. Como príncipio geral considera-se a priori os predicados envolvendo junção bem mais caros do que os predicados simples, e também que não existam diferenças significativas entre os tempos de processamento dos predicados simples, o que leva o otimizador a executar primeiro os predicados simples(em uma ordem qualquer), a fim de se diminuir a quantidade de tuplas que seriam necessárias à execução da junção. Essa consideração que se aplica bem à maioria das aplicações convencionais de banco de dados, passou a não se aplicar mais à novas aplicações que envolviam o preprocessamento de dados e/ou funções complexas nos predicados que não envolviam junções. Dessa forma esses novos predicados simples passaram a ter um tempo de processamento não mais desprezível em relação aos predicados que envolviam junções e também em relação a outros predicados simples. Dessa forma a heurística principal de otimização não se aplicava mais e tornou-se necessário o desenvolvimento de novas técnicas para resolver consultas que envolvessem esse novo tipo de predicado, que passou a ser chamado de predicado caro. O presente trabalho tem dois objetivos principais: apresentar um framework que possibilite o desenvolvimento, teste e análise integrada de algoritmos para o processamento de predicados caros, e analisar o desempenho de quatro implementações de algoritmos baseados na abordagem Cherry Picking, cujo o objetivo é explorar a dependência entre os dados que compõem as consultas. Os experimentos são conduzidos em consultas envolvendo predicados conjuntivos (AND) e a idéia geral é tentar avaliar os atributos em uma ordem que minimize o custo de avaliação geral das tuplas. / [en] Traditional database query optimization technique have as its main heuristic the organization of predicates in two main types: selection predicates and join predicates. Join predicates are considered much more expensive than selection predicates. In additional, it's also considered that there's no big difference among the costs of different selection predicates, what makes the optimizer executes them first in any order, reducing the number of tuples necessary to execute join predicates.This assumption, that is well applied in traditional database applications, becomes invalid in respect of recent database applications, that executes complex functions over complex data in selection predicates. In this cases, selection predicates are considered more expensive than join predicates and their costs cannot be considered equivalent anymore. This makes the main heuristic of push down selections invalid for these kind of new selection predicates which calls for new optimization techniques. These type of cue named expensive predicates. This work has two main objectives: Present a software that makes possible the development, test and integrat analisys of different algorithms for evaluating expensive predicates and analyse the performance of four algorithm's implementations that are based on Cherry Picking strategy, which aims at exploring the data dependency between input values to expensive predicates. The experiments considered conjunctive(AND) queries, and the general idea is to try evaluate the attributes in a order that minimizes the general cost of the tuples.
5

Standardisering eller lokalisering? : En jämförande studie av två modeföretag i olika prisklassers anpassning i Kina / Standardization or localization? : A comparative study of two fashion companies in different price brackets adaptation in China

Odell, Mattias January 2022 (has links)
Cultural differences lead companies to either standardize or localize their marketing when internationalizing into other countries. The purpose of the study is to gain a deeper and broader understanding of how western brands market themselves in China. This is done by examining how two brands in different price brackets choose to standardize or localize their marketing in China. The two brands are: Louis Vuitton and H&M. After determining to which degree these two brands adapt to China there will be a comparison. Two theories from Hofstede (1983) are presented and used to illustrate cultural differences. The study also uses cultural factors such as: language, colors, clothes, and model’s ethnicity to determine to which degree the two brands adapt to China. The country of origin effect is also presented and used to see if it is visible in the marketing directed to China. To answer the research question a qualitative study of the two fashion brands website, Weibo and Twitter was conducted. The results and conclusion show that marketing of western brands in both high and low-price brackets in China uses a combination of standardization and localization but to different degrees. The lower priced brand localizes more than the brand with higher prices. The adaptation that occurs is dependent on the national culture and the price bracket the brand exists in. How western brands relate to national cultures for advertising purposes continue to be of interest for future studies.
6

The Impact of moisture and clay content on the unconfined compressive strength of lime treated highly reactive clays

Muhmed, A., Mohamed, Mostafa H.A., Khan, A. 06 September 2022 (has links)
Yes / This study aims to provide a thorough evaluation for the changes in the microstructure and evolution of strength of highly reactive clays that were treated with 7 % lime over a period of curing time as a function of the mixing moisture content. Three series of testing were carried out on specimens with 100 %, 85 % and 75 % of bentonite content and prepared with different moisture content of 10, 20, 30 and 40 % above the corresponding optimum moisture content. Specimens of 100 % bentonite were treated with 7 % of lime, compacted to achieve a predetermined dry unit weight and cured at temperatures of 20 OC and 40 OC for up to 28 days whereas the specimens with 85 % and 75 % of bentonite content were prepared by the addition of sand and were cured at 20 oC for up to 7 days. Unconfined Compressive Strength tests and Scanning Electron Microscopy were conducted to observe the strength and the microstructural changes resulting from increasing mixing moisture content. California Bearing Ratio and Resilient Modulus were correspondingly determined based on correlations with the Unconfined Compressive Strength. The failure pattern was also studied to better understand the ultimate behaviour of lime stabilised clays. The results revealed that the strength of treated bentonite increased with the increase in the moisture content up to 30 % above the corresponding optimum moisture content and with increasing the curing time and temperature. Nevertheless, substituting bentonite with sand on the specimen resulted in a significant reduction on the attained strength. Furthermore, the results of California Bearing Ratio and Resilient Modulus showed that values for both parameters are significantly enhanced with lime treatment. The microstructural analysis provided visual evidence to the improved strength in which the pozzolanic reaction was found to be significantly affected by the amount of moisture in the mixture. The results suggested that compacting lime treated expansive clays with moisture content moderately higher than the optimum moisture content would result in a significant enhancement to the attained strength over the period of curing.
7

Surrogate-Assisted Evolutionary Algorithms

Loshchilov, Ilya 08 January 2013 (has links) (PDF)
Les Algorithmes Évolutionnaires (AEs) ont été très étudiés en raison de leur capacité à résoudre des problèmes d'optimisation complexes en utilisant des opérateurs de variation adaptés à des problèmes spécifiques. Une recherche dirigée par une population de solutions offre une bonne robustesse par rapport à un bruit modéré et la multi-modalité de la fonction optimisée, contrairement à d'autres méthodes d'optimisation classiques telles que les méthodes de quasi-Newton. La principale limitation de AEs, le grand nombre d'évaluations de la fonction objectif, pénalise toutefois l'usage des AEs pour l'optimisation de fonctions chères en temps calcul. La présente thèse se concentre sur un algorithme évolutionnaire, Covariance Matrix Adaptation Evolution Strategy (CMA-ES), connu comme un algorithme puissant pour l'optimisation continue boîte noire. Nous présentons l'état de l'art des algorithmes, dérivés de CMA-ES, pour résoudre les problèmes d'optimisation mono- et multi-objectifs dans le scénario boîte noire. Une première contribution, visant l'optimisation de fonctions coûteuses, concerne l'approximation scalaire de la fonction objectif. Le meta-modèle appris respecte l'ordre des solutions (induit par la valeur de la fonction objectif pour ces solutions) ; il est ainsi invariant par transformation monotone de la fonction objectif. L'algorithme ainsi défini, saACM-ES, intègre étroitement l'optimisation réalisée par CMA-ES et l'apprentissage statistique de meta-modèles adaptatifs ; en particulier les meta-modèles reposent sur la matrice de covariance adaptée par CMA-ES. saACM-ES préserve ainsi les deux propriété clé d'invariance de CMA-ES~: invariance i) par rapport aux transformations monotones de la fonction objectif; et ii) par rapport aux transformations orthogonales de l'espace de recherche. L'approche est étendue au cadre de l'optimisation multi-objectifs, en proposant deux types de meta-modèles (scalaires). La première repose sur la caractérisation du front de Pareto courant (utilisant une variante mixte de One Class Support Vector Machone (SVM) pour les points dominés et de Regression SVM pour les points non-dominés). La seconde repose sur l'apprentissage d'ordre des solutions (rang de Pareto) des solutions. Ces deux approches sont intégrées à CMA-ES pour l'optimisation multi-objectif (MO-CMA-ES) et nous discutons quelques aspects de l'exploitation de meta-modèles dans le contexte de l'optimisation multi-objectif. Une seconde contribution concerne la conception d'algorithmes nouveaux pour l'optimi\-sation mono-objectif, multi-objectifs et multi-modale, développés pour comprendre, explorer et élargir les frontières du domaine des algorithmes évolutionnaires et CMA-ES en particulier. Spécifiquement, l'adaptation du système de coordonnées proposée par CMA-ES est couplée à une méthode adaptative de descente coordonnée par coordonnée. Une stratégie adaptative de redémarrage de CMA-ES est proposée pour l'optimisation multi-modale. Enfin, des stratégies de sélection adaptées aux cas de l'optimisation multi-objectifs et remédiant aux difficultés rencontrées par MO-CMA-ES sont proposées.
8

Incidence of Income Tax in the Mandate without Representation to Buy Goods / Incidencia del Impuesto a la Renta en el Mandato sin Representación para Comprar Bienes

Hidalgo Vargas Machuca, Raúl Antonio 10 April 2018 (has links)
This article aims to determine the nature of the mandate without representation in the purchase of goods and their tax effects, so the author starts analyzing the corresponding figure of sending with and without representation, in order to understand its inner workings and confront within the tax Income. In that sense, the author believes that the president transfer of ownership is not onerous, each having different implications course within the income tax. / El presente artículo tiene como objetivo determinar la naturaleza del mandato sin representación en la compra de bienes y sus efectos tributarios. Así, se parte del análisis del mandato con y sin representación, entendiendo su mecánica interna y confrontándola en relación al Impuesto a la Renta.En ese sentido, el autor considera que para el mandatario la transferencia de propiedad no resulta onerosa, teniendo cada supuesto implicancias distintas dentro del Impuesto a la Renta.
9

A Software Product Line for Parameter Tuning

Pukhkaiev, Dmytro 09 August 2023 (has links)
Optimization is omnipresent in our world. Its numerous applications spread from industrial cases, such as logistics, construction management or production planning; to the private sphere, filled with problems of selecting daycare or vacation planning. In this thesis, we concentrate on expensive black-box optimization (EBBO) problems, a subset of optimization problems (OPs), which are characterized by an expensive cost of evaluating an objective function. Such OPs are reoccurring in various domains, being known as: hyperpameter optimization in machine learning, performance configuration optimization or parameter tuning in search-based software engineering, simulation optimization in operations research, meta-optimization or parameter tuning in the optimization domain itself. High diversity of domains introduces a plethora of solving approaches, which adhere to a similar structure and workflow, but differ in details. The software frameworks stemming from different areas possess only partially intersecting manageability points, i.e., lack manageability. In this thesis, we argue that the lack of manageability in EBBO is a major problem, which leads to underachieving optimization quality. The goal of this thesis is to study the role of manageability in EBBO and to investigate whether improving the manageability of EBBO frameworks increases optimization quality. To reach this goal, we appeal to software product line engineering (SPLE), a methodology for developing highly-manageable software systems. Based on the foundations of SPLE, we introduce a novel framework for EBBO called BRISE. It offers: 1) a loosely-coupled software architecture, separating concerns of the experiment designer and the developer of EBBO strategies; 2) a full coverage of all EBBO problem types; and 3) a context-aware variability model, which captures the experiment-designer-defined OP with the content model; and manageability points including their variants and constraints with the cardinality-based feature model. High manageability of the introduced BRISE framework enables us: 1) to extend the framework with novel efficient strategies, such as adaptive repetition management; and 2) to introduce novel EBBO mechanisms, such as multi-objective compositional surrogate modeling, dynamic sampling and hierarchical surrogate modeling. The evaluation of the novel approaches with a set of case studies, including: the WFG benchmark for multi-objective optimization, combined selection and parameter control of meta-heuristics, and energy optimization; demonstrated their superiority over the state-of-the-art competitors. Thus, it supports the research hypothesis of this thesis: Improving manageability of an EBBO framework enables to increase optimization quality.
10

Kriging-assisted evolution strategy for optimization and application in material parameters identification / Contribution à l’optimisation évolutionnaire assistée par modèle de Krigeage : application à l’identification des paramètres en mécanique

Huang, Changwu 06 April 2017 (has links)
Afin de réduire le coût de calcul pour des problèmes d'optimisation coûteuse, cette thèse a été consacrée à la Stratégie d'Evolution avec Adaptation de Matrice de Covariance assistée par modèle de Krigeage (KA-CMA-ES). Plusieurs algorithmes de KA-CMA-ES ont été développés et étudiés. Une application de ces algorithmes KA-CMA-ES développés est réalisée par l'identification des paramètres matériels avec un modèle constitutif d'endommagement élastoplastique. Les résultats expérimentaux démontrent que les algorithmes KA-CMA-ES développés sont plus efficaces que le CMA-ES standard. Ils justifient autant que le KA-CMA-ES couplé avec ARP-EI est le plus performant par rapport aux autres algorithmes étudiés dans ce travail. Les résultats obtenus par l'algorithme ARP-EI dans l'identification des paramètres matériels montrent que le modèle d'endommagement élastoplastique utilisé est suffisant pour décrire le comportement d'endommage plastique et ductile. Ils prouvent également que la KA-CMA-ES proposée améliore l'efficace de la CMA-ES. Par conséquent, le KA-CMA-ES est plus puissant et efficace que CMA-ES pour des problèmes d'optimisation coûteuse. / In order to reduce the cost of solving expensive optimization problems, this thesis devoted to Kriging-Assisted Covariance Matrix Adaptation Evolution Strategy (KA-CMA-ES). Several algorithms of KA-CMA-ES were developed and a comprehensive investigation on KA-CMA-ES was performed. Then applications of the developed KA-CMA-ES algorithm were carried out in material parameter identification of an elastic-plastic damage constitutive model. The results of experimental studies demonstrated that the developed KA-CMA-ES algorithms generally are more efficient than the standard CMA-ES and that the KA-CMA-ES using ARP-EI has the best performance among all the investigated KA-CMA-ES algorithms in this work. The results of engineering applications of the algorithm ARP-EI in material parameter identification show that the presented elastic-plastic damage model is adequate to describe the plastic and ductile damage behavior and also prove that the proposed KA-CMA-ES algorithm apparently improve the efficiency of the standard CMA-ES. Therefore, the KA-CMA-ES is more powerful and efficient than CMA-ES for expensive optimization problems.

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