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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.
11

Development of a Logit model of the transition effect to public transport

Ziedén, Therése January 2017 (has links)
The importance of traffic planning has, throughout the years, been in- creased, providing sustainable developments of traffic and infrastructural investments. The analysis of the current traffic situation and the evalua- tion of the effects of a future investment are crucial for the socio-economic benefits maintenance. These analyses and evaluations are most commonly done using traffic simulation models. One of the main traffic planning aims, nowadays, is to increase the number of public transport users against the number of private car users. This change in mode choice is called transition effect and could be beneficial both from an environmental and socio-economic perspective. This thesis aims to evaluate and improve the macroscopic traffic demand and transition model, used fot the city of Norrköping. Additionally, the thesis investigates if a general transition Logit model can be developed and which parameters are the most important to be included in a modal choice estimation. For the needs of this study, the traffic planning software Visum is used. The travel mode distribution is calculated by Logit models coded in Python-scripts integrated in Visum. Then, a traffic assignment is performed by Visum, computing new travel times as inputs to the Logit model and this iterative procedure continues until the system reaches an equilibrium. The thesis aims for a more reliable prediction of the transition effect by correcting the Python-scripts and estimating the parameters of the Logit model using data from surveys. The study shows that travel times is the most important factor for realistic results generation. However, the data used for the estimation of the Logit model parameters did not include sufficient information of travel times. The travel times had to be calculated, using two different methods, in order to be included in the estimation of new parameters. Although these methods could not provide any positive effects on the transition, they did prove the importance and significance travel time have when developing a traffic model. The result of the study invokes the importance to further develop the method of calculating travel times, when the input data is not sufficient, and shows that the travel time parameters are case specific.
12

Modeling Permissive Left-Turn Gap Acceptance Behavior at Signalized Intersections

Zohdy, Ismail Hisham 04 December 2009 (has links)
The research presented in this thesis, studies driver gap acceptance behavior for permissive left turn movements at signalized intersections. The thesis attempts to model the gap acceptance behavior using three different approaches, a deterministic statistical approach, a stochastic approach, and a psycho-physical approach. First, the deterministic statistical modeling approach is conducted using logistic regression to characterize the impact of a number of variables on driver gap acceptance behavior. The variables studied are the gap duration, the driver's wait time in search of an acceptable gap, the time required to travel to clear the conflict point, and the rain intensity. Considering stochastic gap acceptance, two stochastic approaches are compared, namely: a Bayesian and a Bootstrap approach. The study develops a procedure to model stochastic gap acceptance behavior while capturing model parameter correlations without the need to store all parameter combinations. The model is then implemented to estimate stochastic opposed saturation flow rates. Finally, the third approach uses a psycho-physical modeling approach. The physical component captures the vehicle constraints on gap acceptance behavior using vehicle dynamics models while the psychological component models the driver deliberation and decision process. In general, the three proposed models capture gap acceptance behavior for different vehicle types, roadway surface conditions, weather effects and types of control which could affect the driver gap acceptance behavior. These findings can be used to develop weather responsive traffic signal timings and can also be integrated into emerging IntelliDrive systems. / Master of Science
13

Predikce výskytu skoků na denním trhu s elektřinou v České republice / Forecasting Jump Occurrence in Czech Day-Ahead Power Market

Hortová, Jana January 2016 (has links)
The very specific features of the spot prices, especially occurrence of severe jumps, create a spot price risk for retailers who purchase electricity at unregulated highly volatile prices but resell it to consumers at fixed price. Therefore, it is of high im- portance to forecast whether jump is likely to occur during the next hour. However, to the best of our knowledge, such research has not been devoted to the Czech power market yet. Therefore, the aim of this thesis is to forecast the jump occurrence in the Czech day-ahead market. For this purpose we suggest four logit model spec- ifications, each containing various independent variables (for example, electricity demand, outside temperature, lagged price and various dummy variables) where the variable selection is supported by the previous literature and by the characteristic features of the spot prices. Within the in-sample period we compare the suggested models based on the values of pseudo-R squared and Bayesian information criterion. When evaluating the out-of sample performance of suggested models we apply jump prediction accuracy and confidence, but opposed to the previous literature we sug- gest a kind of sensitivity analysis which, to the best of our knowledge, has not be proposed by any other power research. JEL Classification C25, C32, C51,...
14

Ensaios em economia da saúde : o risco e o valor de uma vida estatística no caso dos acidentes de trânsito na cidade de Porto Alegre

Sousa, Tanara Rosângela Vieira January 2010 (has links)
Nesta tese são desenvolvidos três estudos sobre o risco associado aos acidentes de trânsito, com o objetivo de avaliar como a população o percebe, e o valor que estaria disposta a pagar para reduzi-lo. As análises foram feitas com duas diferentes metodologias econométricas e dois diferentes conjuntos de dados da população de Porto Alegre. O primeiro estudo procurou avaliar que fatores de risco contribuem para aumentar a gravidade dos acidentes de trânsito, utilizando dados de acidentes de trânsito ocorridos na cidade de Porto Alegre no período 2000-2008, através de modelos logit ordenados generalizados. Os resultados indicam que a maioria das vítimas feridas em acidentes de trânsito são condutores jovens, do sexo masculino e que estavam em motocicletas ou cujo acidente foi um choque contra obstáculos. Contudo, as vítimas fatais têm maior probabilidade de morte são os pedestres, com mais de 60 anos de idade. Os acidentes com maior gravidade ocorrem em maior proporção a noite ou finais de semana, em locais mais afastados do centro da cidade, o que sugere comportamento associado à alta velocidade e uso de substâncias psicoativas como álcool. Para os demais estudos utilizaram-se dados de um survey feito com a população de Porto Alegre em 2009. O segundo estudo avalia como as características sócio-demográficas, a experiência no trânsito e a informação recebida, afetam a percepção do risco e o comportamento no trânsito. Os resultados indicam que os indivíduos que tem risco maior de morte no trânsito subestimam seu próprio risco e vice-versa; e que os mais jovens têm maior percepção deste risco, assim como os que tiveram experiência de acidente de trânsito ou passam mais tempo expostos a ele. O risco do consumo de bebidas alcoólicas associado ao trânsito, no entanto é percebido maior pelos idosos, mulheres, não bebedores ou quem não tem comportamento de risco, assim como pelos que têm mais informação do risco. Da mesma maneira, o comportamento de risco no trânsito associado ao consumo de álcool está negativamente relacionado a percepção deste risco e a idade. O terceiro estudo estimou a disposição a pagar ( ) dos entrevistados pela redução no seu próprio risco de sofrer lesões em um acidente de trânsito e o valor de uma vida estatística ( ), utilizando modelos lineares e não-lineares ajustados através de uma transformação Box-Cox. Os resultados indicam que a esta relacionada de forma decrescente com a idade e com a não utilização de dispositivos de segurança, mas aumenta com a renda, o tempo de exposição ao trânsito, a experiência com acidentes, para as mulheres e para os que têm dependentes. O valor médio eliciado da para reduzir a zero o risco das lesões mais graves, que resultam em morte, implicou em de cerca de R$ 13,4 milhões (US$7,3 milhões) - valor menor, porém comparável ao encontrado para países desenvolvidos e em estudo para o Brasil. / This thesis develops three studies on the risk associated with traffic accidents, in order to assess how people perceive it and the value they would be willing to pay to reduce it. The analysis was made with two different econometric methods and two different sets of data from Porto Alegre's population. The first study to assess at risk factors that contribute to increased severity of accidents, using data obtained from traffic accidents in the city of Porto Alegre between the years 2000 and 2008, and applying the generalized ordered logit. The results indicate that most of the victims injured in accidents are young drivers, males, motorcyclists and whose crash was a “collision with obstacles”. However, fatal victims have a different profile: they are pedestrians, over 60 years old. The most serious accidents occur in greater proportions at nights or weekends, at locations further away from the city center, which suggests behavior associated with high speed driving and the use of psychoactive substances, such as alcohol. The other two studies used data from a survey done with the population of Porto Alegre in 2009. The second study evaluates how socio-demographic characteristics, traffic experience and the information received about the risks of driving under the influence of alcohol, affect risk perception and behavior in the traffic. The results indicate that individuals who have greater risk of dying in traffic, underestimate their own risk and vice versa; and that young people as well as those who have been in an accident or those who spend a lot of time in traffic, have a greater perception of their risk. On the other hand, the risk of alcohol consumption associated with traffic, is perceived better by older people, women, non-drinkers, people without risky behavior, and those who are more aware of the risks of driving under the influence of alcohol. Similarly, risky behavior in traffic, related to alcohol consumption, is inversely proportional to perception of risk and to age. The third study estimated the respondents' willingness to pay ( ) for the reduction in their risk of suffering injuries in a traffic accident, as well as the value of a statistical life ( ), using linear and nonlinear models adjusted by the Box-Cox transformation. The results indicate that the decreases with age and with not using safety devices, but increases with income, exposure to traffic, and the accidents experience, for women and for those who have dependents. The average value elicited by to reduce to zero the risk of severe injuries that result in death, implied a of about R$13.4 million (US$ 7.3 million) - lower, but still a comparable value to that found in developed countries, and studied in Brazil.
15

Ensaios em economia da saúde : o risco e o valor de uma vida estatística no caso dos acidentes de trânsito na cidade de Porto Alegre

Sousa, Tanara Rosângela Vieira January 2010 (has links)
Nesta tese são desenvolvidos três estudos sobre o risco associado aos acidentes de trânsito, com o objetivo de avaliar como a população o percebe, e o valor que estaria disposta a pagar para reduzi-lo. As análises foram feitas com duas diferentes metodologias econométricas e dois diferentes conjuntos de dados da população de Porto Alegre. O primeiro estudo procurou avaliar que fatores de risco contribuem para aumentar a gravidade dos acidentes de trânsito, utilizando dados de acidentes de trânsito ocorridos na cidade de Porto Alegre no período 2000-2008, através de modelos logit ordenados generalizados. Os resultados indicam que a maioria das vítimas feridas em acidentes de trânsito são condutores jovens, do sexo masculino e que estavam em motocicletas ou cujo acidente foi um choque contra obstáculos. Contudo, as vítimas fatais têm maior probabilidade de morte são os pedestres, com mais de 60 anos de idade. Os acidentes com maior gravidade ocorrem em maior proporção a noite ou finais de semana, em locais mais afastados do centro da cidade, o que sugere comportamento associado à alta velocidade e uso de substâncias psicoativas como álcool. Para os demais estudos utilizaram-se dados de um survey feito com a população de Porto Alegre em 2009. O segundo estudo avalia como as características sócio-demográficas, a experiência no trânsito e a informação recebida, afetam a percepção do risco e o comportamento no trânsito. Os resultados indicam que os indivíduos que tem risco maior de morte no trânsito subestimam seu próprio risco e vice-versa; e que os mais jovens têm maior percepção deste risco, assim como os que tiveram experiência de acidente de trânsito ou passam mais tempo expostos a ele. O risco do consumo de bebidas alcoólicas associado ao trânsito, no entanto é percebido maior pelos idosos, mulheres, não bebedores ou quem não tem comportamento de risco, assim como pelos que têm mais informação do risco. Da mesma maneira, o comportamento de risco no trânsito associado ao consumo de álcool está negativamente relacionado a percepção deste risco e a idade. O terceiro estudo estimou a disposição a pagar ( ) dos entrevistados pela redução no seu próprio risco de sofrer lesões em um acidente de trânsito e o valor de uma vida estatística ( ), utilizando modelos lineares e não-lineares ajustados através de uma transformação Box-Cox. Os resultados indicam que a esta relacionada de forma decrescente com a idade e com a não utilização de dispositivos de segurança, mas aumenta com a renda, o tempo de exposição ao trânsito, a experiência com acidentes, para as mulheres e para os que têm dependentes. O valor médio eliciado da para reduzir a zero o risco das lesões mais graves, que resultam em morte, implicou em de cerca de R$ 13,4 milhões (US$7,3 milhões) - valor menor, porém comparável ao encontrado para países desenvolvidos e em estudo para o Brasil. / This thesis develops three studies on the risk associated with traffic accidents, in order to assess how people perceive it and the value they would be willing to pay to reduce it. The analysis was made with two different econometric methods and two different sets of data from Porto Alegre's population. The first study to assess at risk factors that contribute to increased severity of accidents, using data obtained from traffic accidents in the city of Porto Alegre between the years 2000 and 2008, and applying the generalized ordered logit. The results indicate that most of the victims injured in accidents are young drivers, males, motorcyclists and whose crash was a “collision with obstacles”. However, fatal victims have a different profile: they are pedestrians, over 60 years old. The most serious accidents occur in greater proportions at nights or weekends, at locations further away from the city center, which suggests behavior associated with high speed driving and the use of psychoactive substances, such as alcohol. The other two studies used data from a survey done with the population of Porto Alegre in 2009. The second study evaluates how socio-demographic characteristics, traffic experience and the information received about the risks of driving under the influence of alcohol, affect risk perception and behavior in the traffic. The results indicate that individuals who have greater risk of dying in traffic, underestimate their own risk and vice versa; and that young people as well as those who have been in an accident or those who spend a lot of time in traffic, have a greater perception of their risk. On the other hand, the risk of alcohol consumption associated with traffic, is perceived better by older people, women, non-drinkers, people without risky behavior, and those who are more aware of the risks of driving under the influence of alcohol. Similarly, risky behavior in traffic, related to alcohol consumption, is inversely proportional to perception of risk and to age. The third study estimated the respondents' willingness to pay ( ) for the reduction in their risk of suffering injuries in a traffic accident, as well as the value of a statistical life ( ), using linear and nonlinear models adjusted by the Box-Cox transformation. The results indicate that the decreases with age and with not using safety devices, but increases with income, exposure to traffic, and the accidents experience, for women and for those who have dependents. The average value elicited by to reduce to zero the risk of severe injuries that result in death, implied a of about R$13.4 million (US$ 7.3 million) - lower, but still a comparable value to that found in developed countries, and studied in Brazil.
16

Ensaios em economia da saúde : o risco e o valor de uma vida estatística no caso dos acidentes de trânsito na cidade de Porto Alegre

Sousa, Tanara Rosângela Vieira January 2010 (has links)
Nesta tese são desenvolvidos três estudos sobre o risco associado aos acidentes de trânsito, com o objetivo de avaliar como a população o percebe, e o valor que estaria disposta a pagar para reduzi-lo. As análises foram feitas com duas diferentes metodologias econométricas e dois diferentes conjuntos de dados da população de Porto Alegre. O primeiro estudo procurou avaliar que fatores de risco contribuem para aumentar a gravidade dos acidentes de trânsito, utilizando dados de acidentes de trânsito ocorridos na cidade de Porto Alegre no período 2000-2008, através de modelos logit ordenados generalizados. Os resultados indicam que a maioria das vítimas feridas em acidentes de trânsito são condutores jovens, do sexo masculino e que estavam em motocicletas ou cujo acidente foi um choque contra obstáculos. Contudo, as vítimas fatais têm maior probabilidade de morte são os pedestres, com mais de 60 anos de idade. Os acidentes com maior gravidade ocorrem em maior proporção a noite ou finais de semana, em locais mais afastados do centro da cidade, o que sugere comportamento associado à alta velocidade e uso de substâncias psicoativas como álcool. Para os demais estudos utilizaram-se dados de um survey feito com a população de Porto Alegre em 2009. O segundo estudo avalia como as características sócio-demográficas, a experiência no trânsito e a informação recebida, afetam a percepção do risco e o comportamento no trânsito. Os resultados indicam que os indivíduos que tem risco maior de morte no trânsito subestimam seu próprio risco e vice-versa; e que os mais jovens têm maior percepção deste risco, assim como os que tiveram experiência de acidente de trânsito ou passam mais tempo expostos a ele. O risco do consumo de bebidas alcoólicas associado ao trânsito, no entanto é percebido maior pelos idosos, mulheres, não bebedores ou quem não tem comportamento de risco, assim como pelos que têm mais informação do risco. Da mesma maneira, o comportamento de risco no trânsito associado ao consumo de álcool está negativamente relacionado a percepção deste risco e a idade. O terceiro estudo estimou a disposição a pagar ( ) dos entrevistados pela redução no seu próprio risco de sofrer lesões em um acidente de trânsito e o valor de uma vida estatística ( ), utilizando modelos lineares e não-lineares ajustados através de uma transformação Box-Cox. Os resultados indicam que a esta relacionada de forma decrescente com a idade e com a não utilização de dispositivos de segurança, mas aumenta com a renda, o tempo de exposição ao trânsito, a experiência com acidentes, para as mulheres e para os que têm dependentes. O valor médio eliciado da para reduzir a zero o risco das lesões mais graves, que resultam em morte, implicou em de cerca de R$ 13,4 milhões (US$7,3 milhões) - valor menor, porém comparável ao encontrado para países desenvolvidos e em estudo para o Brasil. / This thesis develops three studies on the risk associated with traffic accidents, in order to assess how people perceive it and the value they would be willing to pay to reduce it. The analysis was made with two different econometric methods and two different sets of data from Porto Alegre's population. The first study to assess at risk factors that contribute to increased severity of accidents, using data obtained from traffic accidents in the city of Porto Alegre between the years 2000 and 2008, and applying the generalized ordered logit. The results indicate that most of the victims injured in accidents are young drivers, males, motorcyclists and whose crash was a “collision with obstacles”. However, fatal victims have a different profile: they are pedestrians, over 60 years old. The most serious accidents occur in greater proportions at nights or weekends, at locations further away from the city center, which suggests behavior associated with high speed driving and the use of psychoactive substances, such as alcohol. The other two studies used data from a survey done with the population of Porto Alegre in 2009. The second study evaluates how socio-demographic characteristics, traffic experience and the information received about the risks of driving under the influence of alcohol, affect risk perception and behavior in the traffic. The results indicate that individuals who have greater risk of dying in traffic, underestimate their own risk and vice versa; and that young people as well as those who have been in an accident or those who spend a lot of time in traffic, have a greater perception of their risk. On the other hand, the risk of alcohol consumption associated with traffic, is perceived better by older people, women, non-drinkers, people without risky behavior, and those who are more aware of the risks of driving under the influence of alcohol. Similarly, risky behavior in traffic, related to alcohol consumption, is inversely proportional to perception of risk and to age. The third study estimated the respondents' willingness to pay ( ) for the reduction in their risk of suffering injuries in a traffic accident, as well as the value of a statistical life ( ), using linear and nonlinear models adjusted by the Box-Cox transformation. The results indicate that the decreases with age and with not using safety devices, but increases with income, exposure to traffic, and the accidents experience, for women and for those who have dependents. The average value elicited by to reduce to zero the risk of severe injuries that result in death, implied a of about R$13.4 million (US$ 7.3 million) - lower, but still a comparable value to that found in developed countries, and studied in Brazil.
17

Saggi sul benessere soggetivo sul posto di lavoro. Evidenza empirica per gli Stati Europei. / ESSAYS ON SUBJECTIVE WELL-BEING IN THE WORKPLACE. EVIDENCE FOR EUROPEAN COUNTRIES

DONEGANI, CHIARA PAOLA 13 May 2013 (has links)
La tesi è una raccolta di tre saggi sulla soddisfazione sul posto di lavoro. Il primo capitolo utilizza il dataset panel BHPS per analizzare le differenze di soddisfazione lavorativa dei lavoratori impiegati nel settore nonprofit rispetto agli altri settori. Il secondo considera l'effetto del salario -sia quello del lavoratore che di un gruppo rilevante di riferimento- e degli schemi incentivanti di retribuzione sulla soddisfazione lavorativa. L'analisi si basa sul round 5 dello European Working Conditions Survey (EWCS). Il terzo capitolo analizza e critica la relazione da tempo condivisa in letteratura che i membri di organizzazioni sindacali riportano minore soddisfazione lavorativa rispetto ai non iscritti, mediante l'analisi dei dati dello European Social Survey (ESS),round 3 e 5. / The thesis provides a detailed examination of job satisfaction through three distinct essays. The first chapter uses UK household panel data (the BHPS) to consider differences in job satisfaction in the non-profit sector, compared with other sectors. The second looks at the effect of earnings – that of the respondent and of relevant other people – and of payment systems on job satisfaction. This is based on data from round 5 of the European Working Conditions Survey (EWCS). The third essay seeks to examine and to challenge the long-established finding that union members tend to have lower job satisfaction than non-members, and this is addressed with two rounds of data from the European Social Survey (ESS).
18

Υποδείγματα χρονοσειρών περιορισμένης εξαρτημένης μεταβλητής και μέτρηση της ταχείας διάχυσης αρνητικών χρηματοοικονομικών συμβάντων

Λίβανος, Θεόδωρος 16 June 2011 (has links)
Στόχος της παρούσης διπλωματικής εργασίας είναι να μελετηθεί η Ταχεία Διάχυση Αρνητικών Χρηματοοικονομικών Συμβάντων (financial contagion) όπως αυτή παρουσιάζεται στην βιβλιογραφία καθώς επίσης οι αιτίες, οι τρόποι διάχυσης και οι τρόποι μέτρησης της. Όσον αφορά στο εφαρμοσμένο κομμάτι της υπάρχουσας βιβλιογραφίας εξετάζεται το μέρος αυτής το οποίο αφορά στην εξέταση της Ταχείας Διάχυσης Αρνητικών Χρηματοοικονομικών Συμβάντων με μοντέλα περιορισμένης εξαρτημένης μεταβλητής. Γίνεται εκτενέστερη ανάλυση στο multinomial logit μοντέλο το οποίο φανερώνει την πιθανότητα εμφάνισης ενός ενδεχομένου σε σχέση με τις επεξηγηματικές μεταβλητές που επιλέγονται. Στα πλαίσια της εργασίας αυτής γίνεται και μια εμπειρική εφαρμογή ενός τέτοιου μοντέλου με δεδομένα που αφορούν την Ελληνική Χρηματιστηριακή Αγορά με σκοπό να δειχθεί αν οι χαμηλές αποδόσεις ορισμένων υποδεικτών του Γενικού Δείκτη Τιμών επηρεάζουν την πιθανότητα εμφάνισης ταυτόχρονων κοινών υπερβάσεων στις αποδόσεις (coexceedances) και άλλων υποδεικτών. / The aim of this thesis is to study the rapid dissemination Negative Financial Events (financial contagion) as presented in the literature as well as the causes, ways and methods of diffusion measurement. As far as the applied part of the existing literature is concerned, it is examined the part which concerns the examination of the Rapid Diffusion of Negative Financial Events (financial contagion) with limited dependent variable models. There is extensive analysis of the multinomial logit model. As part of this work it is presented an empirical application of such a model with data from the Greek stock market in order to indicate whether the low returns of certain subindices of the General Price Index affect the likelihood of simultaneous joint excesses in returns (coexceedances) of other subindices .

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