• The Korean Journal of Applied Statistics
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• v.25 no.2
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• pp.363-376
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• 2012

Excessive zeroes are often observed in ordinal categorical response variables. An ordinary ordered Probit model is not appropriate for zero-inflated data especially when there are many different sources of generating 0 observations. In this paper, we apply a two-stage zero-inflated ordered Probit (ZIOP) model which incorporate the zero-flated nature of data, propose a Bayesian analysis of a ZIOP model, and apply the method to alcohol consumption data collected by the National Bureau of Statistics, Korea. In the first stage of a ZIOP model, a Probit model is introduced to divide the non-drinkers into genuine non-drinkers who do not participate in drinking due to personal beliefs or permanent health problems and potential drinkers who did not drink at the time of the survey but have the potential to become drinkers. In the second stage, an ordered probit model is applied to drinkers that consists of zero-consumption potential drinkers and positive consumption drinkers. The analysis results show that about 30% of non-drinkers are genuine non-drinkers and hence the Korean alcohol consumption data has the feature of zero-inflated data. A study on the marginal effect of each explanatory variable shows that certain explanatory variables have effects on the genuine non-drinkers and potential drinkers in opposite directions, which may not be detected by an ordered Probit model.

• Journal of Korean Society of Transportation
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• v.29 no.1
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• pp.95-102
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• 2011

This paper presents a Driving Risk Model (DRM) based on driving speed choices using an Ordered Response Probit (ORP) model. The DRM is conceptualized based on the relation between speed deviation and the occurrence of crashes found by Solomon. The impacts of various driving risk factors are revealed by applying the DRM to evaluate the effectiveness of In-Vehicle Traffic Warning Information (IVTWI) in expressway driving. Regarding driving risk, the results show that: (1) the risk is lower among male drivers, those with more driving experience and those with less accident history, (2) the risk is higher when driving takes place on wet road surface, in the afternoon, and under conditions of low traffic volume, and (3) the risk is also higher on both downgraded and long curve sections. Additionally, the results provide evidence that provision of IVTWI can decrease the driving risk. The proposed DRM provides a solution for assessing the traffic safety impacts of countermeasures on roadways when there is a shortage of traffic accidents data.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.4
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• pp.12-25
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• 2016

The purpose of this study is providing an evaluation criteria for appropriateness of bicycle riding path considering trip purpose based on cyclist's response of importance and satisfaction. The survey presents a quantified criteria of evaluating appropriateness of the bicycle path by investigating difference of impotance and satisfaction between two purposes among 5 selected influence factors about bicycle lane and bicycle parking facility, and in case of commuting purpose, information of destination is additionally considered. All the influence factors are analyzed by Analytical Hierarchy Process (AHP) which yields importance. For the factors which have a huge difference between two purposes, evaluation criteria using a GIS Data of respondent's path and satisfaction of each factors is developed, and other factors are made it by reviewing literature. The importance analyzed by AHP and evaluation criteria can provide a path based LOS for cyclist, and this information can be improved through user's response from app or search engine in the future. and by considering individual's evaluation, it can provide individually specified information.