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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

Understanding and Estimating the Value Travelers Place on Their Trips on Managed Lanes

Patil, Sunil N. 2009 December 1900 (has links)
Travelers' value of travel time savings (VTTS) are often used to estimate the benefits of transportation facilities, including managed lanes (MLs). With various eligibility criteria and time of day pricing on the MLs, the VTTS estimation is complicated. This is evident by the underestimation of VTTS on MLs in many of the previous studies. This study investigates stated preference (SP) survey design strategies and differentiating the VTTS for ordinary and some common urgent situations faced by the travelers in an attempt to improve on VTTS estimation on MLs. This study used three different survey design strategies (including a D-efficient design) in an internet based survey of Katy Freeway travelers. It was found that a random attribute level generation strategy, where the VTTS presented in the alternative was adjusted based on the answer to a previous SP question, performs better than the other two designs with respect to VTTS estimation and other survey design efficiency criteria. The analysis to differentiate the VTTS for ordinary and urgent trips was carried out using the state of art in the mixed logit model estimation. It was found that travelers value their travel time savings much more when facing most of these urgent situations rather than ordinary situations. Both peak and off-peak period travelers' VTTS were also found to be significantly greater when on urgent trips. Survey design attribute level ranges were found to significantly affect the VTTS estimation. Further, in order to understand the policy implications of these findings it was demonstrated that classifying all trips as ordinary can significantly underestimate the VTTS benefits offered by the MLs. Additionally, the VTTS of any urgent trips would be greatly underestimated. The study also demonstrated that many of the low and medium income group travelers on urgent trips can have VTTS greater than that of the highest VTTS traveler from the high income group on an ordinary trip. These findings have significant policy implications since the benefits of MLs (and of most transportation investments) are primarily derived from travel time savings. Underestimating the VTTS and hence the benefits for MLs can result in reducing the likelihood of funding such facilities. This study provides an important first step in the proper estimation of these benefits by suggesting modifications to SP surveys to better capture the influence of urgent trips on the value of a ML facility.
12

Analyzing car ownership and route choices using discrete choice models

Han, Bijun January 2001 (has links)
<p>This thesis consists of two parts. The first part analyzesthe accessibility, generation and license holding effects incar ownership models. The second part develops a route choicemodeling framework with an attempt to address the differencesin drivers' route choice behavior. These two parts of work areboth based on the discrete choice theory - the car ownershipmodels are built up on the standard logit model, whereas theroute choice models are formulated in a mixed logit form.</p><p>The study result of the first part shows that measuring theaccessibility by the monetary inclusive value reasonably wellcaptures the mechanism of the accessibility impact. Otheraccessibility proxies such as the parking costs, parking typeand house type are correlated with the accessibility but not toa great extent. Both young and old households are less likelyto have a car. The reduction of the propensity to own a car issignificant for households with average birth year before 1920,whereas this reduction is moderate for households with birthyear between 1920 and 1945. It is also demonstrated thatdriving license holding choice is conditional on the carownership level choice, and that these two choices need to bemodeled in a dynamic framework.</p><p>The second part of the work investigates the performance ofthe mixed logit model using both simulated data and empiricalroute switching data. The empirical study mainly focused on theimpacts of information and incident related factors on drivers'route switching behavior.</p><p>The result shows that using mixed logit gives a significantimprovement in model performance as well as a more sensitiveexplanation of drivers' decision-making behavior. For apopulation with greatly varying tastes, simply using thestandard logit model to analyze its behavior can yield veryunrealistic results. However, care must be taken when settingthe number of random draws for simulating the choiceprobability of the mixed logit model in order to get reliableestimates.</p><p>The empirical results demonstrate that incident relatedfactors such as delay and information reliability havesignificant impacts on drivers' route switching, where themagnitude of the response to the change in the delay is shownto vary significantly between individuals. Other factors, suchas confidence in the estimated delay, gender, frequency of cardriving and attitude towards congestion, also make majorcontributions. In addition, it is found that individual's routeswitching behavior may differ depending on the purpose of thetrip and when the choice is made, i.e. pre-trip oren-route.</p><p><b>Keywords</b>: car ownership, accessibility, logit model,route choice, heterogeneity, mixed logit model</p>
13

Χαρακτηριστικά και πρόβλεψη επιχειρήσεων στόχων εξαγοράς - συγκριτική ανάλυση και ανάπτυξη νέων οικονομετρικών υποδειγμάτων / Characteristics and prediction of takeover targets - comparative analysis and development of new econometric models

Τσαγκανός, Αθανάσιος 04 February 2008 (has links)
Σκοπός της παρούσας διατριβής είναι η ανάδειξη των χαρακτηριστικών των επιχειρήσεων – στόχων του βιομηχανικού τομέα και η δυνατότητα πρόβλεψης αυτών αποκαλύπτοντας έτσι τα κίνητρα των αγοραστών. Ο σκοπός αυτός επιτυγχάνεται μέσα από ένα διαφοροποιημένο τρόπο ανάπτυξης του θεωρητικού πλαισίου (σε σχέση με τους υφιστάμενους) και κατ’ επέκταση των θεωρητικών υποθέσεων. Σε αντιστοιχία με τις θεωρητικές υποθέσεις αναπτύσσεται η δειγματοληψία και ορίζονται οι μεταβλητές. Συνέπεια τούτου, οι μεταβλητές διακρίνονται σε χρηματοοικονομικές και μη χρηματοοικονομικές. Το κύριο βάρος της εργασίας εστιάζεται στην εφαρμογή εναλλακτικών οικονομετρικών υποδειγμάτων αναφορικά με τους στόχους – εξαγοράς. Η κύρια συνεισφορά της διατριβής εντοπίζεται στη θεωρητική ανάπτυξη και εφαρμογή ενός νέου ουσιαστικά οικονομετρικού υποδείγματος του Bootstrap Mixed Logit (BMXL) που δίνει μια νέα διάσταση τόσο στον εντοπισμό των χαρακτηριστικών των επιχειρήσεων – στόχων όσο και στη δυνατότητα βελτίωσης της πρόβλεψης αυτών. Τέλος η εργασία ολοκληρώνεται εξάγοντας τα κύρια συμπεράσματα και κάνοντας προτάσεις για μελλοντική έρευνα και συνεισφορά. / The purpose of this dissertation is the identification of the characteristics of takeover targets of industrial sector and its predictive ability revealing the motives of buyers. This purpose is achieved using a different theoretical context and manner of sampling. We distinct the variables into financial and non financial. We focus on the application of alternative econometric model relatively to the takeover targets. The contribution of this dissertation is located to the theoretical development and application of a new econometric model the Bootstrap Mixed Logit (BMXL)that provide a new dimension not only on the identification of takeover targets but also on the ability of their prediction. Finally, the dissertation concludes making suggestion for future research.
14

THOROUGHBRED FARM MANAGERS' WILLINGNESS-TO-PAY FOR ALTERNATIVE DEWORMING REGIMENS IN HORSES

Robert, Marion Angélique 01 January 2013 (has links)
Parasite control is important to horse health and horse owners should feel highly concerned about the proper treatment of parasites. In the past 30 years, veterinary science has made important advances in treating parasites and provided new products and strategies to optimize treatment and prevention. However, horse owners and managers have been slow to adopt these new recommendations. This study investigates why the transition has not occurred as expected. It examines issues related to the decision-making process of horse owners and managers as they relate to deworming strategies. In addition, it investigates current deworming approaches as well as attitudes towards alternative parasite control strategies, and tries to describe the financial considerations corresponding to each strategy. To this end, a questionnaire was distributed to Thoroughbred farms in Kentucky. The first part of the questionnaire examined the actual approaches of farm managers and characterized the Kentucky Thoroughbred farms. Most farm managers appear to be concerned about drug resistance in parasites and incorporated veterinarian advice in defining their deworming program; however, almost three-quarters of them were still following the traditional rotational deworming program. Based on a conjoint experiment, we were able to evaluate the willingness-to-pay of farm managers for different attributes of a deworming strategy – time and effort spent, decrease in health risks, drug resistance in parasites, and price. The study showed that farm managers were willing to pay a premium for a strategy that is guaranteed “non-resistant” and that decreased health risk by 5%, while they expected a discount for a strategy that requires much time and effort.
15

世帯内での配分を考慮した自動車の車種選択と利用の分析

山本, 俊行, YAMAMOTO, Toshiyuki, 北村, 隆一, KITAMURA, Ryuichi, 河本, 一郎, KOHMOTO, Ichiro 04 1900 (has links)
No description available.
16

The Effects of Age and Gender on Pedestrian Traffic Injuries: A Random Parameters and Latent Class Analysis

Raharjo, Tatok Raharjo 21 June 2016 (has links)
Pedestrians are vulnerable road users because they do not have any protection while they walk. They are unlike cyclists and motorcyclists who often have at least helmet protection and sometimes additional body protection (in the case of motorcyclists with body-armored jackets and pants). In the US, pedestrian fatalities are increasing and becoming an ever larger proportion of overall roadway fatalities (NHTSA, 2016), thus underscoring the need to study factors that influence pedestrian-injury severity and potentially develop appropriate countermeasures. One of the critical elements in the study of pedestrian-injury severities is to understand how injuries vary across age and gender ‒ two elements that have been shown to be critical injury determinants in past research. In the current research effort, 4829 police-reported pedestrian crashes from Chicago in 2011 and 2012 are used to estimate multinomial logit, mixed logit, and latent class logit models to study the effects of age and gender on resulting injury severities in pedestrian crashes. The results from these model estimations show that the injury severity level for older males, younger males, older females, and younger females are statistically different. Moreover, the overall findings also show that older males and older females are more likely to have higher injury-severity levels in many instances (if a crash occurs on city streets, state maintained urban roads, the primary cause of the crash is failing to yield right-of way, pedestrian entering/ leaving/ crossing is not at intersection, road surface condition is dry, and road functional class is a local road or street). The findings suggest that well-designed and well-placed crosswalks, small islands in two-way streets, narrow streets, clear road signs, provisions for resting places, and wide, flat sidewalks all have the potential to result in lower pedestrian-injury severities across age/gender combinations.
17

Mixed Multinomial Logit Analysis of Bicyclist Injury-severity in Single Motor Vehicle Crashes Based on Intersection and Non Intersection Locations

Moore, Darren N. 05 October 2009 (has links)
No description available.
18

Modeling Intercity Mode Choice and Airport Choice in the United States

Ashiabor, Senanu Y. 30 April 2007 (has links)
The aim of this study was to develop a framework to model travel choice behavior in order to estimate intercity travel demand at nation-level in the United States. Nested and mixed logit models were developed to study national-level intercity transportation in the United States. A separate General Aviation airport choice model to estimates General Aviation person-trips and number of aircraft operations though more than 3000 airports was also developed. The combination of the General Aviation model and the logit models gives the capability to estimate a full spectrum of intercity travel demand in the United States. The logit models were calibrated using a nationwide revealed preference survey (1995 American Travel Survey). Separate models were developed for business and non-business trip purposes. An airport choice model is integrated into the mode choice model to estimate both the market share between any origin-destination pair and other modes of transportation, and the market share split between airports associated with the origin-destination pairs. The explanatory variables used in the utility functions of the models are travel time, travel cost, and traveler's household income. The logit models are used to estimate the market share of automobile and commercial air transportation between 3091 counties and 443 commercial service airports in the United States. The model was also used to estimate market share for on-demand air taxi services. Given an input county-to-county trip demand table, the models were used to estimate county-to-county travel demand by automobile and commercial airline between all counties and commercial service airports in the United States. The model has been integrated into a computer software framework called the Transportation Systems Analysis Model (TSAM) that estimates nationwide intercity travel demand in the United States. / Ph. D.
19

Economic Considerations of Aggressively Treating the Influenza Virus in Equines

Hansen, Charlotte R 01 January 2016 (has links)
The equine influenza virus is a significant cause of respiratory disease in horses. Even though horses generally recover from this virus, sometimes horses with equine influenza develop secondary bacterial infections which can cause severe pneumonia, thereby increasing recovery times. Owners and managers are faced with the decision of whether to delay preventative treatment in hopes of the horse avoids contracting a secondary bacterial infection (“wait and see”) or aggressively treat the horse with an antibiotic in hopes of avoiding a serious infection (“treat now”). From a decision making standpoint, the economic considerations include explicit treatment costs as well as nonmonetary costs the owner or manager bear when caring for an ill horse. This study investigating horse owner/manager preferences for treatment alternatives is approached in two parts. The first part of the study collects data from field practitioners to estimate the cost of treatment strategies under different scenarios. The second part consists of a questionnaire presented to horse owners and managers and includes four choices between alternative treatment strategies. Analyzing the data using a conjoint analysis approach, respondents’ willingness to pay for different elements of a treatment strategy are estimated. Based on treatment strategies and demographic interactions, a respondent was willing to pay to cover the cost of a horse who became ill with the equine influenza, but individual price sensitivities suggested horse owners and managers are willing to “treat now” versus “wait and see” in order to not see their horse feel poorly and miss training time.
20

An application of stated choice to the valuation of bus attributes : a case study of Dhaka, Bangladesh

Mamun, M. A. A. January 2014 (has links)
Bus is the main mode of urban transport in most cities in developing countries. Despite a high mode share, bus service quality is often poor and para-transit services are regarded as a problem in urban transport systems rather than a solution. Using Dhaka as a case study, this thesis investigates bus service quality through identification and valuation of thirteen important attributes using discrete choice models. The attributes examined are travel time, travel cost, waiting time, headway, priority seats for women, crowding inside the bus, boarding and alighting, picking up and dropping off passengers, bus stop facilities, driving quality, driver and crew behaviour, cleanliness inside the bus, and air conditioning. Five focus groups were conducted to identify key qualitative bus attributes and their levels in order to design choice experiments for valuation. A survey of 431 respondents in Dhaka was then undertaken. Two choice experiments were designed and implemented within the survey, each with seven attributes (set A and set B) with travel cost as the common attribute. Multinomial Logit (MNL) models and Mixed Logit (MXL) models were developed using the Dhaka choice data. Twelve of the thirteen attributes were statistically significant at the 99% level. The values of in-vehicle time (IVT), waiting time and headway were BDT 34.80, 47.40 and 64.20 per hour respectively for low income groups in the segmented model. Waiting time has a premium valuation, 1.36 times higher than IVT, which endorses existing evidence. The highest valuation is for the dummy variable seating all the way which is BDT 42.20 for high income females. The next largest was bus stops properly, picks and drops passengers nicely , followed by wide door and mild steps for boarding and alighting , smooth and safe journey , bus stop with shed, but no seating arrangements , and air conditioning . The lowest value was BDT 4.61 for deck and seats are clean and tidy , for the low income group. The WTP for the qualitative attributes is high, but given the poor level of the existing service and low fare levels this seems reasonable. Income has a significant impact on travel cost, as well as gender on priority seats for women and crowding inside the bus. However, household car ownership does not have a significant impact on any of the bus attributes examined. The high income group has 75% higher WTP for A set attributes and 79% higher WTP for B set attributes than low income group. Females have 76% higher WTP for standing comfortably all the way , but 38% higher WTP for seating all the way compared to the male. However, females have a WTP of BDT 0.44 for per percent of priority seats for women in contrast with males who have a WTP of BDT -0.11. There is significant taste heterogeneity for both quantitative and qualitative attributes. The qualitative attributes for picking up and dropping off passengers, boarding and alighting facilities and driving facilities have higher valuation and this attributes came from the existing within the market competition structure in a highly fragmented bus market. Therefore, it is recommended to introduce competition for the market and incentives for bus industry consolidation.

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