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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.
81

SELECTING THE MOST PROBABLE CATEGORY: THE R PACKAGE RS

Jin, Hong 10 1900 (has links)
<p>Selecting the most probable multinomial or multivariate hypergeometric category isa multiple-decision selection problem. In this package, xed sampling and inversesampling are used for selecting the most probable category. This package aims atproviding functionality to calculate, display and plot the probabilities of correctlyselecting the most probable category under the least favorable configuration for thesetwo sampling types. A function for finding the specified smallest acceptable samplesize (or cell quota and expected sample size) is included as well.</p> / Master of Science (MSc)
82

Ranking strategies to support toxicity prediction: a case study on potential lxr binders

Palczewska, Anna Maria, Kovarich, S., Ciacci, A., Fioravanzo, E., Bassan, A., Neagu, Daniel 19 January 2019 (has links)
Yes / The current paradigm of toxicity testing is set within a framework of Mode-of-Action (MoA)/Adverse Outcome Pathway (AOP) investigations, where novel methodologies alternative to animal testing play a crucial role, and allow to consider causal links between molecular initiating events (MIEs), further key events and an adverse outcome. In silico (computational) models are developed to support toxicity assessment within the MoA/AOP framework. This paper focuses on the evaluation of potential binding to the Liver X Receptor (LXR), as this has been identified among the MIEs leading to liver steatosis within an AOP framework addressing repeated dose and target-organ toxicity. The objective of this study was the development of a priority setting strategy, by means of in silico approaches and chemometric tools, to allow for the screening and ranking of chemicals according to their toxicity potential. As a case study, the present paper outlines the methodologies and procedures that have been developed in the context of the COSMOS/cosmetics safety assessment project [4], which developed computational methods in view of supporting cosmetics safety assessment, to rank chemicals based on their potential binding to LXR. Chemicals are ranked based on molecular and QSAR modelling outcomes. The contribution in this paper is threefold: the QSAR model for LXR dataset, an application of molecular modeling approaches, which have been developed and optimized for drug discovery, in the context of toxicology, and finally ranking chemicals based on diverse modelling outcomes. The novelty in this paper consists of the employment of linear (logistic regression) and non-linear (Random Forest) models in the context of ranking chemicals. The results show that these methods can be successfully applied for prioritization of compounds of major concern for potential liver toxicity, and that they perform better than the ranking methods reported in the literature to date (such as total ordering or data fusion). / European Community’s Seventh Framework Program (FP7/2007-2013) COSMOS Project under grant agreement n° 266835 and from Cosmetics Europe.
83

Sampling Laws for Stochastically Constrained Simulation Optimization on Finite Sets

Hunter, Susan R. 24 October 2011 (has links)
Consider the context of selecting an optimal system from among a finite set of competing systems, based on a "stochastic" objective function and subject to multiple "stochastic" constraints. In this context, we characterize the asymptotically optimal sample allocation that maximizes the rate at which the probability of false selection tends to zero in two scenarios: first in the context of general light-tailed distributions, and second in the specific context in which the objective function and constraints may be observed together as multivariate normal random variates. In the context of general light-tailed distributions, we present the optimal allocation as the result of a concave maximization problem for which the optimal solution is the result of solving one of two nonlinear systems of equations. The first result of its kind, the optimal allocation is particularly easy to obtain in contexts where the underlying distributions are known or can be assumed, e.g., normal, Bernoulli. A consistent estimator for the optimal allocation and a corresponding sequential algorithm for implementation are provided. Various numerical examples demonstrate where and to what extent the proposed allocation differs from competing algorithms. In the context of multivariate normal distributions, we present an exact, asymptotically optimal allocation. This allocation is the result of a concave maximization problem in which there are at least as many constraints as there are suboptimal systems. Each constraint corresponding to a suboptimal system is a convex optimization problem. Thus the optimal allocation may easily be obtained in the context of a "small" number of systems, where the quantifier "small" depends on the available computing resources. A consistent estimator for the optimal allocation and a fully sequential algorithm, fit for implementation, are provided. The sequential algorithm performs significantly better than equal allocation in finite time across a variety of randomly generated problems. The results presented in the general and multivariate normal context provide the first foundation of exact asymptotically optimal sampling methods in the context of "stochastically" constrained simulation optimization on finite sets. Particularly, the general optimal allocation model is likely to be most useful when correlation between the objective and constraint estimators is low, but the data are non-normal. The multivariate normal optimal allocation model is likely to be useful when the multivariate normal assumption is reasonable or the correlation is high. / Ph. D.
84

Cidades inteligentes: proposta de um modelo brasileiro multi-ranking de classificação / Smart cities: proposal of a brazilian multi-ranking classification model.

Guimarães, José Geraldo de Araujo 04 May 2018 (has links)
A urbanização acentuada, fenômeno crescente das últimas décadas, tem atingido níveis elevadíssimos e criado enormes desafios para a gestão das cidades, além de trazer uma vasta gama de efeitos nefastos para a qualidade de vida de seus cidadãos. Dados da ONU de 2016, indicam tratar-se de um caminho sem volta, com uma tendência de agravamento nos próximos anos. Para tentar mitigar esta situação, muito se tem discutido em como aumentar o nível de inteligência das cidades e o interesse pelo tema Cidades Inteligentes tem crescido. Apesar disso, ainda não existe consenso sobre um conceito de cidade inteligente. Se há tempos este conceito se baseava exclusivamente no pilar da tecnologia, hoje uma visão mais evoluída e holística incorpora várias outras dimensões. Já a maioria dos modelos de classificação existentes são estrangeiros e não são aderentes à realidade de um país tão diverso e tão desigual quanto o Brasil. No âmbito nacional, existem algumas iniciativas de criação de conceitos e de modelos de classificação, mas, ou são baseados unicamente no componente tecnológico, ou buscam apenas a criação de rankings tradicionais baseados em ponderações arbitrárias de seus formuladores. A dificuldade de adequação do conceito e dos modelos de classificação à realidade brasileira foram os dois motores principais desta tese. O primeiro objetivo foi desenvolver um conceito de cidade inteligente para o contexto brasileiro. O segundo foi propor um modelo multidimensional de classificação, que fugisse aos padrões tradicionais de um ranking e fosse um instrumento efetivo de aprendizagem, benchmarking e de apoio ao planejamento de políticas públicas das cidades. Por meio de um estudo exploratório e descritivo, junto a 3 cidades de portes diferentes do estado de São Paulo, foram desenvolvidas pesquisas de abordagem quantitativa e qualitativa. A primeira utilizou questionários fechados e levantamento de dados em bases de indicadores específicos para o cálculo dos componentes do Índice Brasileiro Multidimensional de Classificação de Cidades Inteligentes - IBMCCI. Este produto final da tese emprega a mesma abordagem orientada ao usuário do U-MULTIRANK, o ranking multidimensional global de universidades da Comunidade Europeia. A versão final do modelo proposto foi disponibilizada para uso dos gestores municipais com a liberdade de seleção das dimensões, dos indicadores e dos municípios equivalentes para análise. A abordagem qualitativa da pesquisa foi conduzida por meio de entrevistas semiestruturadas, junto a 2 especialistas em gestão municipal. Para validar a ferramenta construída utilizou-se a técnica de validação de conteúdo. Chegou-se à conclusão que é necessário ajustar alguns fatores do modelo e adequar a periodicidade de edição do índice para coincidir com o calendário das eleições municipais. Com estas adequações, o IBMCCI demonstrou grande potencial de se tornar uma ferramenta efetiva de apoio para os formuladores de políticas públicas municipais. / The strong urbanization, a phenomenon that has increased in recent decades, has reached a very high level and has created enormous challenges for the management of cities, as well as bringing a wide range of harmful effects to the quality of life of its citizens. UN data of 2016 indicates that this is one-way road, and it\'s forecast to be worse in the coming years. Trying to mitigate this situation, much has been discussed about how to increase the smartness level of the cities and the interest in subject of Smart Cities has grown. Despite this, there is still no consensus on a smart city concept. If for some time this concept was based exclusively on the pillar of technology, today a more evolved and holistic vision would incorporate several other dimensions. Most of the existing classification models are foreign and are not adherent to the reality of a country as diverse and as unequal as Brazil. At the national level, there are some initiatives to create concepts and classification models, but they are based solely on the technological component or they only seek to create traditional rankings based on arbitrary weights of their formulators. The difficulty of adapting the concepts and the classification models to the Brazilian reality were the two main engines of this thesis. The first aim was to develop a concept of Smart cities for the Brazilian context. The second one was to propose a multidimensional classification model, which would escape the traditional standards of a ranking and be an effective tool for learning, benchmarking and supporting the planning of public policies in cities. By means of an exploratory and descriptive study, along with 3 cities of different sizes of the state of São Paulo, research into quantitative and qualitative approaches were developed. The first one used close ended questionnaires and data collection based on specific indicators for the calculation of the components of the Brazilian Multidimensional Smart Cities Classification Index (IBMCCI). This final thesis product employs the same user-oriented approach as U-MULTIRANK, the multidimensional global ranking of European Community universities. The final version of the proposed model was made available for use by municipal managers with the freedom to select dimensions, indicators and equivalent municipalities for analysis. The qualitative approach of the research was conducted through semi-structured interviews, with 2 specialists in municipal management. In order to validate the built tool, the content validity technique was used. It has come to the conclusion that it is necessary to adjust some factors of the model and to adapt the periodicity of edition of the index to coincide with the calendar of the municipal elections. With these adaptations, the IBMCCI has demonstrated great potential to become an effective support tool for municipal public policy makers.
85

Saneamento básico: proposta de ranking dos municípios paulistas / Basic sanitation of the municipalities of São Paulo State: classification proposal based on Law

Nirazawa, Alyni Nomoto 02 December 2016 (has links)
A Lei n°11.445/2007, conhecida como Lei do Saneamento, constitui o marco regulatório do setor de saneamento, define o conceito e estabelece diretrizes nacionais para o saneamento básico. Apesar de terem se passado nove anos da sanção desta lei, ainda verifica-se a necessidade de integrar os componentes do conceito de saneamento básico que são: abastecimento de água, esgotamento sanitário, resíduos sólidos e drenagem urbana; e também de buscar meios para monitorar o saneamento básico nos municípios. Por isso, o objetivo do trabalho é propor uma classificação dos municípios do Estado de São Paulo em forma de ranking com base nas condições de saneamento básico, considerando o conceito proposto pela Lei n° 11.445/2007. A classificação na forma de ranking se justifica devido às crescentes iniciativas internacionais em utilizar indicadores compostos para mensurar o desempenho das cidades e compará-las. O ranking de cidades é importante para influenciar discussões políticas nacionais e internacionais, para monitorar e realizar benchmarking, assim como para estabelecer prioridades de ação. A pesquisa possui uma abordagem qualitativa em um primeiro momento para compreender o tema por meio de entrevistas com especialistas e, em um segundo momento possui uma abordagem quantitativa para classificar os municípios paulistas quanto ao saneamento utilizando análise fatorial exploratória. Como resultado obtido, tem-se a proposta de elaboração do ranking de saneamento básico dos municípios paulistas e a respectiva classificação com base em dados de 2013 do SNIS e Munic. / Law n°11.445 / 2007, known as Sanitation Law, is the regulatory framework of the sanitation sector, which defines what is meant by basic sanitation and establishes national guidelines for basic sanitation and for federal policy. After eight years of this law approval we still need to integrate the dimensions proposed by the concept of sanitation which are: water, sewage, solid waste and urban drainage; and also to seek tools that enable achieving the goals set by the government. Therefore, the objective is to create a ranking tool to classify cities according to sanitation conditions, considering the concept of sanitation proposed by Law 11.445/2007. The ranking classification is justified due to the growing international initiatives in using composite indicators to measure the performance of cities and compare them. The cities\' ranking is important in influencing national and international policy discussions, to monitor and carry out benchmarking, as well as to establish priorities for action. The research has a qualitative approach at first to thoroughly understand the subject through interviews with experts, and a second stage has a quantitative approach to the measurement of the counties sanitation by using factor analysis. The results analysis will be done through the description and comparison of the proposed sanitation ranking with the other proposals identified. As a result, we have the proposal for sanitation ranking of counties and their classification based on 2013 data of SNIS e Munic.
86

Argumentation techniques for existential rules / Techniques d'argumentation pour les règles existentielles

Yun, Bruno 11 July 2019 (has links)
Dans cette thèse, nous étudions les techniques de raisonnement utilisant des graphes d'argumentation générés à partir de bases de connaissances inconsistantes exprimées dans le langage des règles existentielles.Les trois principaux résultats sont les suivants. Tout d'abord, nous étudions les propriétés structurelles des graphes obtenus à partir de bases de connaissances exprimées avec des règles existentielles et nous donnons plusieurs indications sur la manière dont leur génération peut être améliorée. Deuxièmement, nous proposons une technique pour générer un graphe d'argumentation où plusieurs arguments peuvent attaquer collectivement, remplaçant ainsi la relation d'attaque binaire classique et montrons expérimentalement les avantages de cette technique. Troisièmement, nous nous intéressons aux approches fondées sur les classements pour le raisonnement en logique et en argumentation. / In this thesis, we investigate reasoning techniques with argumentation graphs generated from inconsistent knowledge bases expressed in the existential rules language. The existential rules language is a subset of first-order logic in which a knowledge base is composed of two layers: a fact layer and an ontology layer.The fact layer consists of factual knowledge (usually stored in relational databases) whereas the ontology layer consists of reasoning rules of deduction and negative constraints.Since the classical query answering approaches fail in the presence of inconsistencies, we chose to work with an conflict-tolerant reasoning approach that is based on building graphs with structured arguments and attacks from the deductions of the underlying logical knowledge base.The three main results are the following. First, we study how argumentation graphs are obtained from knowledge bases expressed in existential rules, the structural properties of such graphs and show several insights as to how their generation can be improved. Second, we propose a framework that generates an argumentation graph with a special feature called sets of attacking arguments instead of the regular binary attack relation and show how it improves upon the current state-of-the-art using an empirical analysis. Third, we interest ourselves to ranking-based approaches in both the context of query answering and argumentation reasoning. In the former, we introduce a framework that is based on ranking maximal consistent subsets of facts (repairs) in order to have a more productive query answering. In the latter, we set up the foundation theory for semantics that rank arguments in argumentation graphs with sets of attacking arguments.
87

A Query Dependent Ranking Approach for Information Retrieval

Lee, Lian-Wang 28 August 2009 (has links)
Ranking model construction is an important topic in information retrieval. Recently, many approaches based on the idea of ¡§learning to rank¡¨ have been proposed for this task and most of them attempt to score all documents of different queries by resorting to a single function. In this thesis, we propose a novel framework of query-dependent ranking. A simple similarity measure is used to calculate similarities between queries. An individual ranking model is constructed for each training query with corresponding documents. When a new query is asked, documents retrieved for the new query are ranked according to the scores determined by a ranking model which is combined from the models of similar training queries. A mechanism for determining combining weights is also provided. Experimental results show that this query dependent ranking approach is more effective than other approaches.
88

Bradfordizing als alternativer Sacheinstieg: Evaluation thematischer Kernzonenbildung

Mayr, Philipp 24 August 2009 (has links) (PDF)
Insbesondere die Reihenfolge und Struktur der gelisteten Ergebnisse (Ranking) spielt, neben dem direkten Volltextzugriff auf die Dokumente, inzwischen eine entscheidende Rolle beim Design von Suchsystemen. Ziel der Forschung/Doktorarbeit von Philip Mayr ist es, zu untersuchen, ob das vorgestellte alternative Re-Rankingverfahren „Bradfordizing“ im Anwendungsbereich bibliographischer Datenbanken operabel ist und voraussichtlich gewinnbringend in Informationssystemen eingesetzt und dem Nutzer angeboten werden kann. Die Evaluation von Bradfordizing zeigt, dass die Dokumente der Kernzone (Kernzeitschriften) für die meisten Testreihen eine signifikant höhere Precision als Dokumente der Zone 2 und Zone 3 (Peripheriezeitschriften) ergeben. Sowohl für Zeitschriften als auch für Monographien kann ein Relevanzvorteil nach Bradfordizing auf einer sehr breiten Basis von Themen und Fragestellungen an zwei unabhängigen Dokumentkorpora empirisch nachgewiesen werden.
89

Scientific Publishing in Information Systems

Bukvova, Helena, Kruse, Paul, Kummer, Christian 12 January 2015 (has links) (PDF)
Many academic decision makers rely on quantified ranking measures to estimate the quality of journal publications. The aim of this study was to map journals in Information Systems (IS) with regard to their topic and their rank and determine whether there is a relationship between the scope of a journal and its rank. The study used content analysis, applying both qualitative and quantitative methods. The results of the analysis show the existence of relationships between the journal rank, the research area, and the type as well as significant differences in ranking on the three lists. The findings illustrate that ranking measures, as indicators for the quality of research published in a journal ought to be considered only in the context of a particular research area and scientific community.
90

Trust and Profit Sensitive Ranking for the Deep Web and On-line Advertisements

January 2012 (has links)
abstract: Ranking is of definitive importance to both usability and profitability of web information systems. While ranking of results is crucial for the accessibility of information to the user, the ranking of online ads increases the profitability of the search provider. The scope of my thesis includes both search and ad ranking. I consider the emerging problem of ranking the deep web data considering trustworthiness and relevance. I address the end-to-end deep web ranking by focusing on: (i) ranking and selection of the deep web databases (ii) topic sensitive ranking of the sources (iii) ranking the result tuples from the selected databases. Especially, assessing the trustworthiness and relevances of results for ranking is hard since the currently used link analysis is inapplicable (since deep web records do not have links). I formulated a method---namely SourceRank---to assess the trustworthiness and relevance of the sources based on the inter-source agreement. Secondly, I extend the SourceRank to consider the topic of the agreeing sources in multi-topic environments. Further, I formulate a ranking sensitive to trustworthiness and relevance for the individual results returned by the selected sources. For ad ranking, I formulate a generalized ranking function---namely Click Efficiency (CE)---based on a realistic user click model of ads and documents. The CE ranking considers hitherto ignored parameters of perceived relevance and user dissatisfaction. CE ranking guaranteeing optimal utilities for the click model. Interestingly, I show that the existing ad and document ranking functions are reduced forms of the CE ranking under restrictive assumptions. Subsequently, I extend the CE ranking to include a pricing mechanism, designing a complete auction mechanism. My analysis proves several desirable properties including revenue dominance over popular Vickery-Clarke-Groves (VCG) auctions for the same bid vector and existence of a Nash equilibrium in pure strategies. The equilibrium is socially optimal, and revenue equivalent to the truthful VCG equilibrium. Further, I relax the independence assumption in CE ranking and analyze the diversity ranking problem. I show that optimal diversity ranking is NP-Hard in general, and that a constant time approximation algorithm is not likely. / Dissertation/Thesis / Ph.D. Computer Science 2012

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