• Title/Summary/Keyword: Ordered probit models

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Development of Severity Model for Rural Unsignalized Intersection Crashes (지방부 비신호 교차로 교통사고 심각도 예측모형 개발 - 수도권 주변 및 전라북도 지역의 3지 비신호 교차로를 중심으로 -)

  • Lee, Dong-Min;Kim, Eung-Cheol;Sung, Nak-Moon;Kim, Do-Hoon
    • International Journal of Highway Engineering
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    • v.10 no.3
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    • pp.47-56
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    • 2008
  • Generally, accident exposure at intersections is relatively higher than that at roadway segments due to more possibility of merging, diverging, turning, crossing, and weaving maneuver. Furthermore, the traffic accident rate at intersections has been rapidly increasing since 1990's. Since there is more opportunity of conflict at unsignalized intersection, frequency and severity of traffic accident are more severe than signalized intersections. The purpose of the study is to analyze factors causing vehicle crashes and provide intersection design guidelines to improve intersection safety. For this study, vehicle to vehicle crash data of 116 rural 3 legs unsignalized were collected and field surveys were conducted for traffic and geometric conditions. Ordered probit models were developed to analyze the severity of crashes. It was found that weather, obstacles in minor roadsides, presence of major exclusive right lane, presence of major road crosswalk, difference between posted speed of major road and minor road, land-use around intersections, shoulder width of major road, ADT of major road are significant factors for intersection safety.

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An Analysis on the Current Farm Management Record Practices and Characteristics (농업인의 경영기록 실태 및 특성 분석)

  • Lee, Sang-Hak;Choi, Se-Hyun;Son, Chan-Soo;Ha, Hyun-Jung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.7
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    • pp.2937-2948
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    • 2012
  • Record-keeping is one of the most fundamental practices in good farm management as it shows a systemic managerial and analytic data essential for a successful farm operation. Despite such obvious benefits in record-keeping, however, today`s farmers do not take advantage of this practice for various reasons. To make the matter worse, not much research has been done to resolve this incompatibility. Therefore, it is urgent for both the government and the farmers to come up with a better method or book of record-keeping that will show the farmers where their operation has been in the past, where it is now, and where it is heading in the future. This study will survey and analyze the current status of record-keeping practice among farmers using statistic models such as logit and ordered probit model. The results showed that the majority of the farmers lack knowledge about management record. Also, appropriate record-keeping books and related education were not available. Therefore, the government should develop and provide farmers with record-keeping books that are easy to use and at the same time giving proper education about agricultural management skills. Finally, this study suggests some improvement plans about agricultural record-keeping based on the results drawn.

The Effect of Experienced Consumers' Concerns on Willingness to Purchase Battery Electric Vehicles (순수전기차 경험 고객의 우려 요인에 따른 전기차 구매 의사 영향)

  • Jeong, Jikhan
    • Journal of Digital Convergence
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    • v.19 no.6
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    • pp.143-162
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    • 2021
  • Research on consumers' perception and willingness to purchase Battery Electric Vehicles (BEVs) is necessary to simulate BEVs' deployment in South Korea because South Korea's BEVs market is still in the early stage. This paper derives a theoretical framework for consumer segmentation based on consumers' willingness to purchase before and after BEV usage experience. In particular, this study empirically evaluates consumers' willingness to purchase and concerns using the survey data from BEVs users in either Seoul or the Jeju region. The empirical results from logit models show that experienced consumers' concerns about the heater and air conditioning (HAC) in BEVs decreased the consumers' willingness to buy, while greater daily driving distances increased the consumers' willingness to buy. In addition, the empirical findings from ordered probit models show that experienced consumers' concerns about the short driving distance, the availability of maintenance service (i.e., A/S service) during unexpected events, and the difficulties of driving BEVs up-hill increased the degree of concern about HAC. This paper will provide insights related to consumer segmentation, R&D, marketing strategies, and policy design for policymakers and firms.

Development of a Traffic Accident Prediction Model for Urban Signalized Intersections (도시부 신호교차로 안전성 향상을 위한 사고예측모형 개발)

  • Park, Jun-Tae;Lee, Soo-Beom;Kim, Jang-Wook;Lee, Dong-Min
    • Journal of Korean Society of Transportation
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    • v.26 no.4
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    • pp.99-110
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    • 2008
  • It is commonly estimated that there is a much higher potential for accidents at a crossroads than along a single road due to its plethora of conflicting points. According to the 2006 figures by the National Police Agency, the number of traffic accidents at crossroads is greatly increasing compared to that along single roads. Among others, crossroads installed with traffic signals have more varied influential factors for traffic accidents and leave much more room for improvement than ones without traffic signals; thus, it is expected that a noticeable effect could be achieved in safety if proper counter-measures against the hazards at a crossroads were taken together with an estimate of causes for accidents This research managed to develop models for accident forecasts and accident intensity by applying data on accident history and site inspection of crossroads, targeting four selected downtown crossroads installed with traffic signals. The research was done by roughly dividing the process into four stages: first, analyze the accident model examined before; second, select variables affecting traffic accidents; third, develop a model for traffic accident forecasting by using a statistics-based methodology; and fourth, carry out the verification process of the models.