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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.
21

Interpreting random forest models using a feature contribution method

Palczewska, Anna Maria, Palczewski, J., Marchese-Robinson, R.M., Neagu, Daniel January 2013 (has links)
No
22

Crowd formal modelling and simulation: The Sa'yee ritual

Sakellariou, I., Kurdi, O., Gheorghe, Marian, Romano, D.M., Kefalas, P., Ipate, F., Niculescu, I.M. January 2014 (has links)
No / There is an increasing interest in modelling of agents interacting as crowd and a simulation of such scenarios that map to real-life situations. This paper presents a generic state-based abstract model for crowd behaviour that can be mapped onto different agent-based systems. In particular, the abstract model is mapped into the simulation framework NetLogo. We have used the model to simulate a real-life case study of high density diverse crowd such as the Hajj ritual at the mosque in Mecca (Makkah). The computational model is based on real data extracted from videos of the ritual. We also present a methodology for extracting significant data, parameters, and patterns of behaviour from real-world videos that has been used as an early stage validation to demonstrate that the obtained simulations are realistic.
23

Layered ensemble model for short-term traffic flow forecasting with outlier detection

Abdullatif, Amr R.A., Rovetta, S., Masulli, F. 27 January 2020 (has links)
Yes / Real time traffic flow forecasting is a necessary requirement for traffic management in order to be able to evaluate the effects of different available strategies or policies. This paper focuses on short-term traffic flow forecasting by taking into consideration both spatial (road links) and temporal (lag or past traffic flow values) information. We propose a Layered Ensemble Model (LEM) which combines Artificial Neural Networks and Graded Possibilistic Clustering obtaining an accurate forecast of the traffic flow rates with outlier detection. Experimentation has been carried out on two different data sets. The former was obtained from real UK motorway and the later was obtained from simulated traffic flow on a street network in Genoa (Italy). The proposed LEM model for short-term traffic forecasting provides promising results and given the ability for outlier detection, accuracy, robustness of the proposed approach, it can be fruitful integrated in traffic flow management systems.
24

Defining GeoDesign and the emergent role of the sustainable sites initiative (SITES) for integrative project management

Risinger, Emily Diane 16 March 2015 (has links)
This report is a discussion of the multifarious applications of the modern day geographic information system and how the universal merit of the technology across disciplines has led to the emergence of GeoDesign. The purpose of this Master’s Professional Report was to retrace the core conceptual framework and landmark events occurring in the evolution GIS technology, and how these factors have led to recent creation of new performance based rating systems and evidence-based design techniques. The Sustainable Sites Initiative (SITES), a new performance based rating system that has emerged in response to the call for increased knowledge and best practices lacking in LEED, is discussed; along with integrated project management. This professional report was intended to be an exploratory discussion of the larger theoretical implications fueling the shift towards mandating greater standards for sustainable design. It offers some ideas for how we should continue evolving GeoDesign moving into the next century; and outlines the importance of all new rating systems needing to acknowledge the growing importance of GeoDesign and ever advancing imagery technologies in understanding complex system processes in the future. / text
25

Bootstrap for panel data models with an application to the evaluation of public policies

Hounkannounon, Bertrand G. B. 08 1900 (has links)
Le but de cette thèse est d étendre la théorie du bootstrap aux modèles de données de panel. Les données de panel s obtiennent en observant plusieurs unités statistiques sur plusieurs périodes de temps. Leur double dimension individuelle et temporelle permet de contrôler l 'hétérogénéité non observable entre individus et entre les périodes de temps et donc de faire des études plus riches que les séries chronologiques ou les données en coupe instantanée. L 'avantage du bootstrap est de permettre d obtenir une inférence plus précise que celle avec la théorie asymptotique classique ou une inférence impossible en cas de paramètre de nuisance. La méthode consiste à tirer des échantillons aléatoires qui ressemblent le plus possible à l échantillon d analyse. L 'objet statitstique d intérêt est estimé sur chacun de ses échantillons aléatoires et on utilise l ensemble des valeurs estimées pour faire de l inférence. Il existe dans la littérature certaines application du bootstrap aux données de panels sans justi cation théorique rigoureuse ou sous de fortes hypothèses. Cette thèse propose une méthode de bootstrap plus appropriée aux données de panels. Les trois chapitres analysent sa validité et son application. Le premier chapitre postule un modèle simple avec un seul paramètre et s 'attaque aux propriétés théoriques de l estimateur de la moyenne. Nous montrons que le double rééchantillonnage que nous proposons et qui tient compte à la fois de la dimension individuelle et la dimension temporelle est valide avec ces modèles. Le rééchantillonnage seulement dans la dimension individuelle n est pas valide en présence d hétérogénéité temporelle. Le ré-échantillonnage dans la dimension temporelle n est pas valide en présence d'hétérogénéité individuelle. Le deuxième chapitre étend le précédent au modèle panel de régression. linéaire. Trois types de régresseurs sont considérés : les caractéristiques individuelles, les caractéristiques temporelles et les régresseurs qui évoluent dans le temps et par individu. En utilisant un modèle à erreurs composées doubles, l'estimateur des moindres carrés ordinaires et la méthode de bootstrap des résidus, on montre que le rééchantillonnage dans la seule dimension individuelle est valide pour l'inférence sur les coe¢ cients associés aux régresseurs qui changent uniquement par individu. Le rééchantillonnage dans la dimen- sion temporelle est valide seulement pour le sous vecteur des paramètres associés aux régresseurs qui évoluent uniquement dans le temps. Le double rééchantillonnage est quand à lui est valide pour faire de l inférence pour tout le vecteur des paramètres. Le troisième chapitre re-examine l exercice de l estimateur de différence en di¤érence de Bertrand, Duflo et Mullainathan (2004). Cet estimateur est couramment utilisé dans la littérature pour évaluer l impact de certaines poli- tiques publiques. L exercice empirique utilise des données de panel provenant du Current Population Survey sur le salaire des femmes dans les 50 états des Etats-Unis d Amérique de 1979 à 1999. Des variables de pseudo-interventions publiques au niveau des états sont générées et on s attend à ce que les tests arrivent à la conclusion qu il n y a pas d e¤et de ces politiques placebos sur le salaire des femmes. Bertrand, Du o et Mullainathan (2004) montre que la non-prise en compte de l hétérogénéité et de la dépendance temporelle entraîne d importantes distorsions de niveau de test lorsqu'on évalue l'impact de politiques publiques en utilisant des données de panel. Une des solutions préconisées est d utiliser la méthode de bootstrap. La méthode de double ré-échantillonnage développée dans cette thèse permet de corriger le problème de niveau de test et donc d'évaluer correctement l'impact des politiques publiques. / The purpose of this thesis is to develop bootstrap methods for panel data models and to prove their validity. Panel data refers to data sets where observations on individual units (such as households, firms or countries) are available over several time periods. The availability of two dimensions (cross-section and time series) allows for the identi cation of effects that could not be accounted for otherwise. In this thesis, we explore the use of the bootstrap to obtain estimates of the distribution of statistics that are more accurate than the usual asymptotic theory. The method consists in drawing many ran- dom samples that resembles the sample as much as possible and estimating the distribution of the object of interest over these random samples. It has been shown, both theoretically and in simulations, that in many instances,this approach improves on asymptotic approximations. In other words, the resulting tests have a rejection rate close to the nominal size under the null hypothesis and the resulting con dence intervals have a probability of inclu- ding the true value of the parameter that is close to the desired level. In the literature, there are many applications of the bootstrap with panel data, but these methods are carried out without rigorous theoretical justi fication. This thesis suggests a bootstrap method that is suited to panel data (which we call double resampling), analyzes its validity, and implements it in the analysis of treatment e¤ects. The aim is to provide a method that will provide reliable inference without having to make strong assumptions on the underlying data-generating process. The rst chapter considers a model with a single parameter (the overall expectation) with the sample mean as estimator. We show that our double resampling is valid for panel data models with some cross section and/or temporal heterogeneity. The assumptions made include one-way and two- way error component models as well as factor models that have become popular with large panels. On the other hand, alternative methods such as bootstrapping cross-sections or blocks in the time dimensions are only valid under some of these models. The second chapter extends the previous one to the panel linear regression model. Three kinds of regressors are considered : individual characteristics, temporal characteristics and regressors varying across periods and cross-sectional units. We show that our double resampling is valid for inference about all the coe¢ cients in the model estimated by ordinary least squares under general types of time-series and cross-sectional dependence. Again, we show that other bootstrap methods are only valid under more restrictive conditions. Finally, the third chapter re-examines the analysis of di¤erences-in-differences estimators by Bertrand, Du o and Mullainathan (2004). Their empirical application uses panel data from the Current Population Survey on wages of women in the 50 states. Placebo laws are generated at the state level, and the authors measure their impact on wages. By construction, no impact should be found. Bertrand, Dufl o and Mullainathan (2004) show that neglected heterogeneity and temporal correlation lead to spurious ndings of an effect of the Placebo laws. The double resampling method developed in this thesis corrects these size distortions very well and gives more reliable evaluation of public policies.
26

Hodnotící tabulka jako nástroj pro měření makroekonomických nerovnováh / Scoreboard Indicators as a Measure of Macroeconomic Imbalances

Toušková, Daniela January 2013 (has links)
This thesis examined an ability of the scoreboard indicators created by the European Commission to capture macroeconomic imbalances expressed as the changes of GDP. We conducted an empirical analysis for panel data of 27 EU countries in the 1997-2011 period. We adopted three different dynamic panel data models based on the three estimators: the Arrelano- Bond, the Arrelano-Bover and the corrected LSDV estimator. Our results suggest that despite some bad characteristics of our dataset we can conclude that some of the indicators such as 3- year average of current account balance or percentage change in export market shares seem to be inadequate for measuring the imbalances. Moreover, the indicators were proved not to be able to predict an occurrence of imbalances.
27

Modelo navegacional dinâmico, para implementação da integração inter-estrutural de dados. / Dynamic navigational model for implementation of the data inter-structural integration.

Gomes Neto, José 04 November 2016 (has links)
Na última década, observaram-se substanciais mudanças nos tipos de dados processados, quando comparados à definição convencional de dados estruturados. Neste contexto, sistemas computacionais que em sua maioria acessam bases de dados convencionais, centralizadas, que armazenam dados estruturados, necessitam cada vez mais acessarem e processarem também dados não estruturados, distribuídos e em grandes quantidades. Fatores tais como versatilidade em abrigar dados não estruturados, coexistência, integração e difusão de dados complexos a velocidades superiores as velocidades até então observadas, restringem, em determinadas situações, o uso dos modelos de dados convencionais. Dessa forma, nesta Tese é proposto e formalizado um modelo de dados pós relacional, baseado nos conceitos de grafos complexos, também denominados, Redes Complexas. Por intermédio da utilização do modelo de grafos, define-se uma forma de se implementar uma integração inter-estrutural de dados, ou seja, os tradicionais dados estruturados, com os mais recentemente utilizados dados não estruturados, tais como os dados multimídia. Tal integração envolve todas as transações presentes em um banco de dados, ou seja, consulta, inserção, atualização e exclusão de dados. A denominação dada a tal forma de trabalho e implementação foi Modelo Navegacional Dinâmico - MND. Esse modelo representa diferentes estruturas de dados e sobretudo, permite que essas diferentes estruturas coexistam de forma integrada, agregando à informação resultante maior completeza e abrangência. Portanto, o MND associa os benefícios da junção da estrutura das Redes Complexas ao contexto de dados não estruturados, sobretudo no que tange à integração resultante de dados com estruturas distintas, conferindo assim às aplicações que necessitam desta integração, melhoria no aproveitamento dos recursos. / Over the last decade several changes in data processing have been observed when compared to the conventional structured data definition. In such context, computational systems accessing centralized databases need to process large, distributed, non-structured data as well. Factors like versatility in hosting data, coexistence, integration and diffusion of such complex data at high speeds can be, in some cases, troublesome when using conventional data models. In this work a post-relational, graph-based (also known as Complex Network) model, is presented. Such model enables the integration of both structured data and non-structured data, such as multimedia, allowing such structures to coexist. This integration involves all transactions found in a database, such as select, insert, delete and update data. The name given to this form of work and implementation was Navigational Model Dynamic - MND. This model represents different data structures and above all, allows these different structures to coexist in an integrated way, adding to the resulting information greater completeness and comprehensiveness. Hence, MND harnesses the benefits of Complex Network and non-structured data providing all relational data handling already available in other databases but also integration and better use of resources.
28

A modelagem de documentos estruturados multitmídia integrando sistemas de hipertextos e ODA/ODIF / The modeling of multimedia structured documents integrating hypertexts systems and ODA/ODIF

Perez, Celso Roberto January 1994 (has links)
Há um grande numero de aplicações que necessitam manipular documentos. Tal manipulação exige uma gerência dos mesmos nas tarefas de criação, armazenamento, recuperação e transmissão. Estas tarefas devem levar em conta características e aspectos inerentes aos documentos tais como estrutura lógica, estrutura de apresentação e hiperestrutura formada pelas referências internas e externas existentes nos documentos envolvidos. A multimídia estabelece novos requisitos para os sistemas de gerência de documentos estruturados. Gráficos, sons, e imagens contêm informações que enriquecem o conteúdo textual tradicional dos documentos, podendo ser potencialmente explorados pelos usuários em um processo de formulação de consultas e busca de documentos. A complexidade das aplicações que manipulam documentos estruturados e do tipo multimídia exige o apoio de modelos capazes de expressar características semanticamente mais ricas. Desta forma, tais modelos devem permitir modelar as seguintes estruturas: lógica, de apresentação e hiperestrutura. A adoção de um modelo conceitual de documentos é fator determinante nas possibilidades oferecidas para consultas e recuperação dos referidos documentos. Para a especificação e definição de tal modelo, foram consideradas duas possibilidades: i) utilização dos sistemas de hipertextos, nos quais a ênfase é fornecer um corpo estruturado de objetos com ligações conectando objetos relacionados. Aqui, a estrutura está projetada especificamente para auxiliar aos leitores a navegar através da informação, ii) uso do padrão de documentos eletrônicos ODA/ODIF, o qual dá ênfase à composição e controle da forma dos documentos, preocupando-se, também, com a divisão layout-estrutura-conteúdo dos mesmos, mas faltando nele um tratamento específico em relação às características hipertextuais. Neste trabalho se considera que a integração destas duas filosofias permitirá, de uma maneira natural, a modelagem de Documentos Estruturados Multimídia. As pesquisas e propostas para combinar estas duas opções foram escassas no passado e se desconhecem trabalhos deste tipo visando a Gerência de Documentos Estruturados Multimídia. Como resultado desta integração, no presente trabalho é definido e especificado o meta-modelo OHypA (Office HyperDocument Architecture), que pode ser considerado como uma extensão do padrão ODA/ODIF. Tal meta-modelo terá uma aplicação real e prática pela combinação da tecnologia de hipermídia e a representação de documentos do tipo ODA. Assim sendo, uma vez que o presente trabalho trata a modelagem de Documentos Estruturados Multimídia , envolvendo as áreas definidas, ele permitirá o estudo e delineamento de possíveis soluções para problemas comuns resultantes da integração das referidas áreas. Finalmente, serão integrados dois enfoques em pleno desenvolvimento, resultando num meta-modelo orientado a objetos, que será facilmente integrado a um Sistema de Banco de Dados Orientado a Objetos. / There it a great number of applications that need a document manipulation. Such manipulation demands a management of these documents on tasks like creation, storage, recovery and transmission. Such tasks should consider marks and aspects inherent on documents such as logical structure, presentation structure and hyperstructure, shaped by internal and external references existent in the documents involved. Multimedia establishes new requirements for management systems of structured documents. Graphics, sounds and images contain informations which increase the traditional textual content from the documents that might be potentially explored by user in a process of formulation- queries and search for documents. The complexity of the applications that manipulate structured documents and the kind of multimedia, demands support from models which are able to express characteristics semanually ricer. This way, such models must allow the modeling of the following structures: luzical, presentation and hyperstructure. The adoption of a respected model of documents is a main factor on the offered possibilities for queries and recovering of the reported documents. For spt-Afication and definition of such model, two possibilities were considered: i) utilization of hypertexts systems, in which the emphasis is to provide a structured body of objets connecting other objects related. Here, the structure is designed specificity to help re.ers to navigate through the information, ii) application of the electronic documents model ODA/ODIF, which emphasizes the composition and control of the documents shape, worries also about its sharing of layout-structure-content, but lacks an specific treatment in relation to hypertextual characteristics. This work considers that the integration of these two philosophies will allow, in a natural way, the modeling of multimedia structured documents. The researches and proposals to connect these two options used to be rare in the past. Besides, works that emphasizes the Management of Multimedia Structured Documents are unknown. As a result of such integration, this work describes precisely the OHypA metamodel (Office HyperDocument Architecture) which might be consider as an extension of the ODA/ODIF model. This metamodel will have a real and practical application with the connection of hypermedia technology and the representation of ODA documents. This way, since this work is about the modeling of Mul timedia Structured Documents, covering the described areas, it'll allows the study and outline of possible solutions to common problems that come from the integration of such areas. Finally, two topics in development will be integrated, resulting in a objectoriented metamodel, that should be easily integrated in a Object-Oriented Data Base System.
29

Modelo navegacional dinâmico, para implementação da integração inter-estrutural de dados. / Dynamic navigational model for implementation of the data inter-structural integration.

José Gomes Neto 04 November 2016 (has links)
Na última década, observaram-se substanciais mudanças nos tipos de dados processados, quando comparados à definição convencional de dados estruturados. Neste contexto, sistemas computacionais que em sua maioria acessam bases de dados convencionais, centralizadas, que armazenam dados estruturados, necessitam cada vez mais acessarem e processarem também dados não estruturados, distribuídos e em grandes quantidades. Fatores tais como versatilidade em abrigar dados não estruturados, coexistência, integração e difusão de dados complexos a velocidades superiores as velocidades até então observadas, restringem, em determinadas situações, o uso dos modelos de dados convencionais. Dessa forma, nesta Tese é proposto e formalizado um modelo de dados pós relacional, baseado nos conceitos de grafos complexos, também denominados, Redes Complexas. Por intermédio da utilização do modelo de grafos, define-se uma forma de se implementar uma integração inter-estrutural de dados, ou seja, os tradicionais dados estruturados, com os mais recentemente utilizados dados não estruturados, tais como os dados multimídia. Tal integração envolve todas as transações presentes em um banco de dados, ou seja, consulta, inserção, atualização e exclusão de dados. A denominação dada a tal forma de trabalho e implementação foi Modelo Navegacional Dinâmico - MND. Esse modelo representa diferentes estruturas de dados e sobretudo, permite que essas diferentes estruturas coexistam de forma integrada, agregando à informação resultante maior completeza e abrangência. Portanto, o MND associa os benefícios da junção da estrutura das Redes Complexas ao contexto de dados não estruturados, sobretudo no que tange à integração resultante de dados com estruturas distintas, conferindo assim às aplicações que necessitam desta integração, melhoria no aproveitamento dos recursos. / Over the last decade several changes in data processing have been observed when compared to the conventional structured data definition. In such context, computational systems accessing centralized databases need to process large, distributed, non-structured data as well. Factors like versatility in hosting data, coexistence, integration and diffusion of such complex data at high speeds can be, in some cases, troublesome when using conventional data models. In this work a post-relational, graph-based (also known as Complex Network) model, is presented. Such model enables the integration of both structured data and non-structured data, such as multimedia, allowing such structures to coexist. This integration involves all transactions found in a database, such as select, insert, delete and update data. The name given to this form of work and implementation was Navigational Model Dynamic - MND. This model represents different data structures and above all, allows these different structures to coexist in an integrated way, adding to the resulting information greater completeness and comprehensiveness. Hence, MND harnesses the benefits of Complex Network and non-structured data providing all relational data handling already available in other databases but also integration and better use of resources.
30

A influência dos bancos de dados na cultura digital / The influence of the databases in digital culture

Bezerra, William 05 October 2010 (has links)
Made available in DSpace on 2016-04-29T14:22:49Z (GMT). No. of bitstreams: 1 William Bezerra.pdf: 1607820 bytes, checksum: 4afe5e46e8660114b8394ab613a32637 (MD5) Previous issue date: 2010-10-05 / This work is intended to analyze databases and its influence among digital culture. We will show that database usage and database logic are becoming more common than ever in this culture and it is implicit to users. Once we realize this predominance, we ask if database usage can affect the way we understand the world, making this interaction more binary, dichotomous, ordered and more objective, like database logics would do with its formal structures of cataloging and data availability. To answer this question we will analyze database designs, from data modeling to creation and use (Date). Thus, we show how the ideas of a project, initially informal, become formal though the project designer's choices and binary data structure rules, ending up in a product released for use (Setzer). After that, we will see how all of this formal mode including main database features - and digital technology features - come from the military environment of power and control (Gere), also based on quantifier (Crosby) and visual models (Crary) transferred to digital model. Finally, we wrote a case study based on what we have discussed, mainly focused on database logic (Manovich), confirming its presence on all ways, even storing untouchable things, like feelings / Neste trabalho, analisaremos os bancos de dados e suas influências dentro da cultura digital. Evidenciaremos que a utilização de bases de dados e de aplicativos que seguem a sua lógica é cada vez mais predominante na cultura digital, mesmo que isso geralmente não seja percebido, por não haver um contato direto entre os usuários e os dados armazenados. Dada esta predominância, questionaremos se, ao utilizarmos os bancos de dados, pode ocorrer alguma interferência na nossa apreensão e percepção de mundo, de forma que elas sejam mais binárias, dicotômicas, ordenadas e objetivas, ou seja, em conformidade com a lógica dos bancos de dados e suas estruturas formais de catalogação e disponibilização de dados. Para averiguar esses questionamentos, elaboraremos uma análise crítica sobre a concepção dos bancos de dados, desde os modelos de dados até sua implementação e utilização (Date). Com isso, demonstraremos como as idéias para o projeto, a princípio informais, formalizam-se mediante as escolhas dos seus criadores e as imposições e regras das estruturas de dados binárias, finalmente culminando em um produto acabado que é, enfim, liberado para utilização (Setzer). Em seguida, veremos como toda esta formalização e as principais funcionalidades dos bancos de dados e das tecnologias digitais como um todo , advêm de pressupostos definidos em sua fase de desenvolvimento inicial, dentro de um contexto militar de poder e controle (Gere), também baseados em alicerces quantificadores (Crosby) e visuais (Crary), herdados e repassados ao digital. Por último, realizaremos um estudo de um caso prático fundamentado nos pressupostos discutidos no transcorrer de todo o trabalho e focado principalmente na lógica dos bancos de dados (Manovich), confirmando sua presença em todas as circunstâncias, sendo utilizada inclusive para catalogar coisas, a princípio fluídas, como por exemplo, os sentimentos

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