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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.
131

Smart task logging : Prediction of tasks for timesheets with machine learning

Bengtsson, Emil, Mattsson, Emil January 2018 (has links)
Every day most people are using applications and services that are utilising machine learning, in some way, without even knowing it. Some of these applications and services could, for example, be Google’s search engine, Netflix’s recommendations, or Spotify’s music tips. For machine learning to work it needs data, and often a large amount of it. Roughly 2,5 quintillion bytes of data are created every day in the modern information society. This huge amount of data can be utilised to make applications and systems smarter and automated. Time logging systems today are usually not smart since users of these systems still must enter data manually. This bachelor thesis will explore the possibility of applying machine learning to task logging systems, to make it smarter and automated. The machine learning algorithm that is used to predict the user’s task, is called multiclass logistic regression, which is categorical. When a small amount of training data was used in the machine learning process the predictions of a task had a success rate of about 91%.
132

Practice location of physicians: a discrete choice model approach

Nunes, Letícia Faria de Carvalho 07 April 2015 (has links)
Submitted by Letícia Nunes (leticiafcnunes@gmail.com) on 2015-06-11T16:44:52Z No. of bitstreams: 1 Dissertação - Leticia Nunes - Practice Location of Physicians.pdf: 569206 bytes, checksum: bde07c17bc4ab59a76a947e9fa27f35e (MD5) / Approved for entry into archive by BRUNA BARROS (bruna.barros@fgv.br) on 2015-06-18T13:46:34Z (GMT) No. of bitstreams: 1 Dissertação - Leticia Nunes - Practice Location of Physicians.pdf: 569206 bytes, checksum: bde07c17bc4ab59a76a947e9fa27f35e (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2015-06-29T12:13:05Z (GMT) No. of bitstreams: 1 Dissertação - Leticia Nunes - Practice Location of Physicians.pdf: 569206 bytes, checksum: bde07c17bc4ab59a76a947e9fa27f35e (MD5) / Made available in DSpace on 2015-06-29T12:13:22Z (GMT). No. of bitstreams: 1 Dissertação - Leticia Nunes - Practice Location of Physicians.pdf: 569206 bytes, checksum: bde07c17bc4ab59a76a947e9fa27f35e (MD5) Previous issue date: 2015-04-07 / Economists and policymakers have long been concerned with increasing the supply of health professionals in rural and remote areas. This work seeks to understand which factors influence physicians’ choice of practice location right after completing residency. Differently from previous papers, we analyse the Brazilian missalocation and assess the particularities of developing countries. We use a discrete choice model approach with a multinomial logit specification. Two rich databases are employed containing the location and wage of formally employed physicians as well as details from their post-graduation. Our main findings are that amenities matter, physicians have a strong tendency to remain in the region they completed residency and salaries are significant in the choice of urban, but not rural, communities. We conjecture this is due to attachments built during training and infrastructure concerns.
133

Prevalência de fatores associados à ocorrência de acidentes viários no entorno de pontos de parada em corredores de ônibus

Machado, Rafaela César January 2017 (has links)
Com o crescimento da população em áreas urbanas, o transporte coletivo assume um importante papel nos deslocamentos diários nas cidades brasileiras. No entanto, o grande volume de pessoas no entorno desses sistemas podem resultar em pontos críticos de segurança viária. Recentemente, as pesquisas sobre melhorias na segurança viária estão se direcionando para a investigação da relação entre o ambiente construído - isto é, padrões de uso do solo; desenho urbano; e sistemas de transporte - e acidentalidade. Porém, a relação entre os sistemas de transporte coletivo por ônibus e o ambiente construído ainda é pouco explorada. O ponto mais crítico em segurança identificado na literatura em sistemas de transporte coletivo são as estações de embarque e desembarque. Assim, esta dissertação tem como objetivo verificar a existência de relação entre elementos do ambiente construído com a ocorrência e severidade de acidentes viários no entorno de pontos de parada em sistemas prioritários para ônibus. Para isso, aplicou-se os modelos de regressão Binomial Negativo (NB), na análise de frequência de acidentes, e os modelos Logit Ordenado (OL) e Logit Multinomial (MNL), para a análise de severidade. No modelo de frequência de acidentes totais, identificou-se duas variáveis significativas e, no modelo estimado para atropelamentos, três variáveis. O modelo de severidade resultou em 19 variáveis significativas para acidentes totais e oito variáveis significativas para atropelamentos. As variáveis referentes ao envolvimento de motocicletas, automóveis, presença de interseção e uso diversificado do solo foram as mais recorrentes. O estudo possibilitou também avaliar as diferenças e vantagens entre os modelos ordenados e os não-ordenados. O modelo Logit Multinomial teve ajustes levemente melhores do que o Logit Ordenado. Ressalta-se, entretanto, que o ajuste do modelo não deve ser o único critério a se considerar na escolha de modelos para o estudo de severidade de acidentes. / Public transport has played an important role in daily commutes in Brazilian cities as population grows in urban areas. However, high volumes of pedestrians near those systems may result in critical safety issues. Recent studies on road safety improvements have sought for evidence on the relationship between built environment - land use patterns; urban design; and transportation systems - and traffic safety. Nevertheless, the relationship between traffic safety at bus priority systems and the built environment is still incipient. According to studies, the most critical safety issues related to public transport are the stations for boarding and alighting. Thus, this thesis aims to verify the relationship between built environment and incidence and severity of traffic crashes in the surroundings of bus priority systems. To do so, we applied Negative Binomial regression models (NB) for the frequency analysis, and the Ordered Logit (OL) and Multinomial Logit (MNL) models for severity analysis. NB models resulted in two significant variables for traffic crashes in general and three variables for pedestrian crashes. The severity model resulted in 19 significant variables overall crashes and eight significant variables for pedestrian crashes. Variables related to the involvement of motorcycles, automobiles, intersections and mixed land use were significant in majority of model estimations. The results allowed to evaluate the goodness of fit between ordered and unordered models. MNL had a slightly better adjustments compared to OL. Goodness of fit, however, should not be the only criterion for selecting a model to assess crash severity.
134

Prevalência de fatores associados à ocorrência e severidade de acidentes com bicicleta em Porto Alegre

Silva, André Luiz Dultra Nascimento da January 2018 (has links)
Após o fim da Segunda Guerra Mundial, teve início um processo de aumento da utilização dos automóveis nos grandes centros urbanos que modificou o desenho das cidades e o padrão de deslocamento nesses espaços. Uma das diversas consequências negativas da consolidação do automóvel como principal meio de transporte nas metrópoles foi o aumento do número de acidentes no trânsito, principalmente os que envolviam os usuários de transporte ativo – pedestres e ciclistas. A promoção dos modos de transporte não motorizados, como a bicicleta, é tida como ação complementar para reversão desse processo, porém, para tanto, é necessário melhorar a percepção de segurança sobre o modo cicloviário. A tomada de decisão por parte dos gestores do tráfego acerca das intervenções viárias que melhoram a segurança dos ciclistas carece de entendimento sobre os elementos que influenciam a ocorrência de acidentes envolvendo estes usuários. Desse modo, o trabalho desenvolvido nesta dissertação tem como objetivo a verificação da existência de relação entre os elementos urbanos construídos, os fatores socioeconômicos e outras possíveis fontes de risco com a frequência e severidade dos acidentes cicloviários na cidade de Porto Alegre O processo de investigação utilizou softwares de georreferenciamento para consolidar os dados coletados segundo as unidades de análise definidas. A frequência de acidentes foi modelada através de Modelo de Regressão Binomial Negativo e a severidade de acidentes foi modelada através de Modelo Logit Multinomial. O modelo de frequência de acidentes apresentou duas variáveis significativas. Em seguida, foi gerado um novo modelo de frequência de acidentes a partir da eliminação de possíveis fontes de discrepância dos dados. Os resultados indicaram que este segundo modelo estava melhor ajustado ao cenário estudado. O modelo de severidade de acidentes foi composto por 18 variáveis significativas. Por fim, os elementos que demonstraram maior prevalência sobre a acidentalidade de ciclistas foram a interação com automóveis, a presença de vias arteriais, a proximidade com áreas de interseção e o envolvimento de usuários vulneráveis (jovens e idosos em bicicletas) nos acidentes. / After the end of the World War II, many cities around the world have experienced an increase on car using which changed the way cities were planned and also mobility patterns. That process has generated some problems at urban areas like road accidents increasing, most of them related to active transport modes - pedestrians and cyclers. Non motorized transportation modes fomentation, for example cycling, emerges as an alternative to change this issue. However, before it happens, cyclers need to feel more safe on transit. Understanding the influence of the elements that affect cyclers's safety gives to decision makers and traffic managers a better possibility to make the right decisions on safety improvement. Thus, this thesis aims to verify the relationship between built environment, socialeconomic factors and other risk sources and frequency and severity of traffic crashes involving cyclists in Porto Alegre. By using GIS softwares, the collected data were consolidated according to the defined analysis units. Accident’s frequencies were modeled and the coefficients were estimated by using Negative Binomial Regression Model and the severity of accidents was modeled as a Multinomial Logit Model. The accident frequency model counted with two sginificant variables. Then, a new accident frequency model was estimated from the elimination of possible sources of data discrepancy. Results have shown that the second model fit better on the studied scenario. The accident severity model resulted in 18 significant variables. Finally, the elements that showed highest prevalences on cyclists safety were car interaction, presence of arterial roads, proximity to intersection areas and vulnerable cyclists users (young and old ones cycling) involvement on accidents.
135

Prevalência de fatores associados à ocorrência de acidentes viários no entorno de pontos de parada em corredores de ônibus

Machado, Rafaela César January 2017 (has links)
Com o crescimento da população em áreas urbanas, o transporte coletivo assume um importante papel nos deslocamentos diários nas cidades brasileiras. No entanto, o grande volume de pessoas no entorno desses sistemas podem resultar em pontos críticos de segurança viária. Recentemente, as pesquisas sobre melhorias na segurança viária estão se direcionando para a investigação da relação entre o ambiente construído - isto é, padrões de uso do solo; desenho urbano; e sistemas de transporte - e acidentalidade. Porém, a relação entre os sistemas de transporte coletivo por ônibus e o ambiente construído ainda é pouco explorada. O ponto mais crítico em segurança identificado na literatura em sistemas de transporte coletivo são as estações de embarque e desembarque. Assim, esta dissertação tem como objetivo verificar a existência de relação entre elementos do ambiente construído com a ocorrência e severidade de acidentes viários no entorno de pontos de parada em sistemas prioritários para ônibus. Para isso, aplicou-se os modelos de regressão Binomial Negativo (NB), na análise de frequência de acidentes, e os modelos Logit Ordenado (OL) e Logit Multinomial (MNL), para a análise de severidade. No modelo de frequência de acidentes totais, identificou-se duas variáveis significativas e, no modelo estimado para atropelamentos, três variáveis. O modelo de severidade resultou em 19 variáveis significativas para acidentes totais e oito variáveis significativas para atropelamentos. As variáveis referentes ao envolvimento de motocicletas, automóveis, presença de interseção e uso diversificado do solo foram as mais recorrentes. O estudo possibilitou também avaliar as diferenças e vantagens entre os modelos ordenados e os não-ordenados. O modelo Logit Multinomial teve ajustes levemente melhores do que o Logit Ordenado. Ressalta-se, entretanto, que o ajuste do modelo não deve ser o único critério a se considerar na escolha de modelos para o estudo de severidade de acidentes. / Public transport has played an important role in daily commutes in Brazilian cities as population grows in urban areas. However, high volumes of pedestrians near those systems may result in critical safety issues. Recent studies on road safety improvements have sought for evidence on the relationship between built environment - land use patterns; urban design; and transportation systems - and traffic safety. Nevertheless, the relationship between traffic safety at bus priority systems and the built environment is still incipient. According to studies, the most critical safety issues related to public transport are the stations for boarding and alighting. Thus, this thesis aims to verify the relationship between built environment and incidence and severity of traffic crashes in the surroundings of bus priority systems. To do so, we applied Negative Binomial regression models (NB) for the frequency analysis, and the Ordered Logit (OL) and Multinomial Logit (MNL) models for severity analysis. NB models resulted in two significant variables for traffic crashes in general and three variables for pedestrian crashes. The severity model resulted in 19 significant variables overall crashes and eight significant variables for pedestrian crashes. Variables related to the involvement of motorcycles, automobiles, intersections and mixed land use were significant in majority of model estimations. The results allowed to evaluate the goodness of fit between ordered and unordered models. MNL had a slightly better adjustments compared to OL. Goodness of fit, however, should not be the only criterion for selecting a model to assess crash severity.
136

Prevalência de fatores associados à ocorrência e severidade de acidentes com bicicleta em Porto Alegre

Silva, André Luiz Dultra Nascimento da January 2018 (has links)
Após o fim da Segunda Guerra Mundial, teve início um processo de aumento da utilização dos automóveis nos grandes centros urbanos que modificou o desenho das cidades e o padrão de deslocamento nesses espaços. Uma das diversas consequências negativas da consolidação do automóvel como principal meio de transporte nas metrópoles foi o aumento do número de acidentes no trânsito, principalmente os que envolviam os usuários de transporte ativo – pedestres e ciclistas. A promoção dos modos de transporte não motorizados, como a bicicleta, é tida como ação complementar para reversão desse processo, porém, para tanto, é necessário melhorar a percepção de segurança sobre o modo cicloviário. A tomada de decisão por parte dos gestores do tráfego acerca das intervenções viárias que melhoram a segurança dos ciclistas carece de entendimento sobre os elementos que influenciam a ocorrência de acidentes envolvendo estes usuários. Desse modo, o trabalho desenvolvido nesta dissertação tem como objetivo a verificação da existência de relação entre os elementos urbanos construídos, os fatores socioeconômicos e outras possíveis fontes de risco com a frequência e severidade dos acidentes cicloviários na cidade de Porto Alegre O processo de investigação utilizou softwares de georreferenciamento para consolidar os dados coletados segundo as unidades de análise definidas. A frequência de acidentes foi modelada através de Modelo de Regressão Binomial Negativo e a severidade de acidentes foi modelada através de Modelo Logit Multinomial. O modelo de frequência de acidentes apresentou duas variáveis significativas. Em seguida, foi gerado um novo modelo de frequência de acidentes a partir da eliminação de possíveis fontes de discrepância dos dados. Os resultados indicaram que este segundo modelo estava melhor ajustado ao cenário estudado. O modelo de severidade de acidentes foi composto por 18 variáveis significativas. Por fim, os elementos que demonstraram maior prevalência sobre a acidentalidade de ciclistas foram a interação com automóveis, a presença de vias arteriais, a proximidade com áreas de interseção e o envolvimento de usuários vulneráveis (jovens e idosos em bicicletas) nos acidentes. / After the end of the World War II, many cities around the world have experienced an increase on car using which changed the way cities were planned and also mobility patterns. That process has generated some problems at urban areas like road accidents increasing, most of them related to active transport modes - pedestrians and cyclers. Non motorized transportation modes fomentation, for example cycling, emerges as an alternative to change this issue. However, before it happens, cyclers need to feel more safe on transit. Understanding the influence of the elements that affect cyclers's safety gives to decision makers and traffic managers a better possibility to make the right decisions on safety improvement. Thus, this thesis aims to verify the relationship between built environment, socialeconomic factors and other risk sources and frequency and severity of traffic crashes involving cyclists in Porto Alegre. By using GIS softwares, the collected data were consolidated according to the defined analysis units. Accident’s frequencies were modeled and the coefficients were estimated by using Negative Binomial Regression Model and the severity of accidents was modeled as a Multinomial Logit Model. The accident frequency model counted with two sginificant variables. Then, a new accident frequency model was estimated from the elimination of possible sources of data discrepancy. Results have shown that the second model fit better on the studied scenario. The accident severity model resulted in 18 significant variables. Finally, the elements that showed highest prevalences on cyclists safety were car interaction, presence of arterial roads, proximity to intersection areas and vulnerable cyclists users (young and old ones cycling) involvement on accidents.
137

Bayesian Inference in the Multinomial Logit Model

Frühwirth-Schnatter, Sylvia, Frühwirth, Rudolf January 2012 (has links) (PDF)
The multinomial logit model (MNL) possesses a latent variable representation in terms of random variables following a multivariate logistic distribution. Based on multivariate finite mixture approximations of the multivariate logistic distribution, various data-augmented Metropolis-Hastings algorithms are developed for a Bayesian inference of the MNL model.
138

Potential Implication of Automated Vehicle Technologies on Travel Behavior and System Modeling

Sadat Lavasani Bozorg, Seyed Mohammad Ali 01 November 2016 (has links)
Autonomous Vehicles (AVs) are computer equipped vehicles that can operate without human driver’s active control using information provided by their sensors about the surrounding environment. Self-driving vehicles may have seemed to be a distant dream several years ago, but manufactures’ prototypes showed that AVs are becoming real now. Several car manufactures (i.e. Benz, Audi, etc.) and information technology firms (i.e. Google) have either showcased their fully AVs or announced their robot cars to be released in a few years. AVs hold the promise to transform the ways we live and travel. Although several studies have been conducted on the impacts of AVs, much remains to be explored regarding the various ways in which AVs could reshape our lifestyle. This dissertation addresses the knowledge gap in understanding the potential implications of AV technologies on travel behavior and system modeling. A comprehensive review of literature regarding AV adoption, potential impacts and system modeling was provided. Bass diffusion models were developed to investigate the market penetration process of AVs based on experience learned from past technologies. A stated preference survey was conducted to gather information from university population on the perceptions and attitudes toward AV technologies. The data collected from the Florida International University (FIU) was used to develop econometric models exploring the willingness to pay and relocation choices of travelers in light of the new technologies. In addition, the latest version of the Southeast Planning Regional Model (SERPM) 7.0, an Activity-Based Model (ABM), was employed to examine the potential impacts of AVs on the transportation network. Three scenarios were developed for short-term (2035), mid-term (2045) and long-term (2055) conditions. This dissertation provides a systematic approach to understand the potential implications of AV technologies on travel behavior and system modeling. The results of the survey data analysis and the scenario analysis also provide important inputs to guide planning and policy analysis on the impacts of AV technologies.
139

Využití zobecněného lineárního modelu k analýze splácení retailových úvěrů / Retail loan repayment analysis using generalized linear models

Šolc, Michal January 2009 (has links)
This Diploma thesis concern with generalized linear models and their application in bank practice. Especially to analyze retail loan repayment. First of all we see into theoretical viewpoint of generalized linear models. We shortly try to summarize problems of clasical linear model restrictions and after that we apply to theory on which generalized models are based. We introduce an overview of generalized linear models and after that we concern models, where dependent variable have multinomial and gamma distribution in detail. Main part this thesis is dedicated to data analysis about bank retail loans repayments. In this analysis we use those early mentioned models. We try to create good statistical models on which base the risk ratio of current bank clients could be predicted. The risk ratio is measured by two main indicators, which are: "overdue time" and "overdue amount". For analysis is used statistical software SAS.
140

Modelování vývoje úmrtnosti v České republice / Modeling of the Mortality Development in the Czech Republic

Hejdová, Martina January 2011 (has links)
The thesis deals with a mortality modelling in the Czech Republic. The main aim of this thesis is to describe historical development of mortality in the Czech Republic on the basis of multinomial regression. In a theoretical part the basic knowledge demanded for model construction divided into two chapters can be found. In the first chapter the basic difference between linear and generalized linear model is described. Second chapter is devoted to a logistic regression. Here we proceed from simple, binomial variable and then we generalize it for multinomial variable. Practical part deals with a construction of a described model. In the third chapter data (type and source) are described and in the fourth chapter characterizes all three models itself (two of them are descriptive and the third one is used for simple prediction). The prediction is added rather for completeness than for the importance of the work itself because it was not the main goal.

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