• Journal of Korean Society of Transportation
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• v.25 no.2 s.95
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• pp.51-61
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• 2007

Increasing traffic volumes and excessively high speeds on national highways through small towns often increases the frequency of accidents. Extensive paved areas, narrow sidewalks, median barriers and little greenery have resulted in a dangerous and destructive living environment for residents. The reason for this problem is that throughways were expanded without considering the harmony between the throughways and the small towns. Construction of bypasses and reclassification of highway functions would solve the problem by reducing vehicle speeds in small towns, but this method is too costly and time consuming. Therefore, this study analyzes national highways through small towns as a case studies using positive guidance in order to improve safety and develop alternatives. As a result of the case study, the biggest problem was observed to be the excessively high vehicle speeds, This study also identified places were information should be given or posted but is currently absent. Therefore, this study concludes that notional highways through small towns need installation of speed reduction facilities and additional information provision to drivers.

• International Journal of Highway Engineering
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• v.10 no.4
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• pp.139-150
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• 2008

In this study, It is focused on development of the forecasting model about trumpet InterChange(IC) ramp accident because of the frequency of accident in ramp more than highway basic section and trend the increasing accident in ramp. The independent variables was selected through statistical analysis(correlation analysis, multi-collinearity etc) by ramp types(direct, semi-direct and loop). The independent variables and accident rate is non-linear relationship. So it made new variables by transformation of the independent variables. The forecasting models according to exit-ramp type (direct, semi-direct and loop) are built with statistical multi-variable regression using all possible regression method. And the forecasts of the models showed high accuracy statistically. It is expected that the developed models could be employed to design trumpet IC ramp more cost-efficiently and safely and to analyze the causes of traffic accidents happened on the IC ramp.

• Journal of Korean Society of Transportation
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• v.21 no.1
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• pp.21-40
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• 2003

A traffic accident analysis method was developed and tested based on the highway alignment risk indices using geographic information systems(GIS). Impacts of the highway alignment on traffic accidents have been identified by examining accidents occurred on different alignment conditions and by investigating traffic accident risk indices(TARI). Evaluative criteria are suggested using geometric design elements as an independent variable. Traffic accident rates were forecasted more realistically and objectively by considering the interaction between highway alignment factors and the design consistency. And traffic accident risk indices and risk ratings were suggested based on model estimation results and accident data. Finally, forecasting traffic accident rates, evaluating the level of risk and then visualizing information graphically were combined into one system called risk assessment system by means of GIS. This risk assessment system is expected to play a major role in designing four-lane highways and developing remedies for highway sections susceptible to traffic accidents.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.5
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• pp.1-14
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• 2020

The aim of this study is to analyze effects of factors on the number of vehicles involved in traffic accidents on freeway sections. In previous studies about traffic accident severity, the analysis of accidents involving multiple vehicles was insufficient. However, multiple-vehicle accidents are likely to cause casualties and are the main reasons increasing accident duration and social costs. In this study, the number of vehicles involved in an accident was interpreted as the result of the accident, not as the cause of the accident, and the impacts of each accident factor were analyzed using a multinomial logit model. The results indicate that multiple-vehicle accidents are mainly related to following factors: nighttime, driver's faults, obstacles on the road, a downhill slope, heavy vehicles, and freeway mainline sections including tunnels and bridges.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.5
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• pp.64-76
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• 2008

To increase road safety at blackspots, it is needed to develop a new method that can process before accident occurrence. Accident situation could result from traffic conflict. Traffic conflict decision technique has an advantage that can acquire and analyze data in time and confined space that is less through investigation. Therefore, traffic conflict technique is highly expected to be used in many application of road safety. This study developed traffic conflict decision program that can analyze and process from signalized intersection image. Program consists of the following functional modules: an image input module that acquires images from the CCTV camera, a Save-to-Buffer module which stores the entered images by differentiating them into background images, current images, difference images, segmentation images, and a conflict detection module which displays the processed results. The program was developed using LabVIEW 8.5 (a graphic language) and the VISION module library.

• Journal of the Korea Society of Computer and Information
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• v.27 no.1
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• pp.141-148
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• 2022

Global climate change caused by greenhouse gases(GHG) is getting serious. To prevent this, countries around the world are regulating GHG emissions. Korea has decided to reduce GHG emissions by 37% compared to BAU (Business As Usual) by 2030. The transportation sector accounted for 18.58% of the domestic GHG emission, and roads accounted for 93.75% of the total. Public transportation is also included in the target of GHG reduction, and this study was conducted to reduce GHG emissions of bus public transportation, which can reduce GHG emissions while reducing the cost of road transportation. In this study, a simulation was conducted to predict the optimal GHG emission compared to the waiting time of passengers by adjusting the bus dispatch interval by implementing a greenhouse gas simulation model using Any Logic. If a more precise model is implemented in the future, it is expected that it will be used to reduce bus GHG emissions.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.1
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• pp.52-64
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• 2023

This paper concentrated on estimating the travel time value of individual regional bus passengers in various in-vehicle crowding conditions. In the analysis model, the traffic-selection data of individual transportation passengers based on smart-card data were used. Variables which reflect the level of in-vehicle crowding and the variables of in-vehicle travel time that reflect the level of in-vehicle crowding were included in the model using Box-Cox transformation. The result of this paper indicates that the travel time value experienced by individual users would increase as the in-vehicle crowding level increases. The smart card data used in this paper is considered to have significant implications in terms of conducting more sophisticated and realistic qualitative research to reflect the values of variables for in-vehicle traffic hours and in-vehicle crowding levels, which previously had limitations in observation and quantification. It is expected that the effects of improvement measures for reducing congestion on regional buses can be considered quantitatively by applying the estimation results of crowding multiplier.

• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.91-100
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• 2007

This study suggests direct connection service which has advantage of high-speed operation of KTX and access convenience of general train, and Pre-feasibility studies on the direct connection service. And analyze transportation demand change by the method as follows; It is to analyze the demand change of before and after KTX operation by previous transport data of Gyeongbu line, and calculate the coefficient of utilization using triggering demand by opening the 2nd phase of Gyeongbu line (Dongdaegu${\sim}$Busan). Through Pre-feasibility analysis, reduction $70{\sim}100$ minutes of train travel time and total revenue will increase about $100 thousand per day. Also, there will be environment-friendly effects of decreasing $CO_2$ emissions. But, Direct connection service need to highly cost ; Buying and Operation cost of KTX train. Therefore, we will be get more correct result of Pre-feasibility study on direct connection service, if there are concrete on buying the KTX action plans.

• Journal of Korean Society of Transportation
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• v.26 no.6
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• pp.103-112
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• 2008

Implementing hub networks in logistics is generally attractive and effective because of cost savings derived from economies of scale on network transportation, and objective of the hub network design problem is to decide optimal hub locations, and the transportation route of each origin-destination pair. This problem is generally a NP-complete problem not to solve easily, and it is almost impossible to find optimal solutions considering the big-sized network within a reasonable time. This research tried to find optimal logistics strategy in the given big-sized real network and the freight origin-destination data. The objective function, which was proposed by Honor and O'kelly (2001), that rewards economies of scale on network links with increase of transportation volumes, is applied. This thesis proposed the optimal hub network of korea within a reasonable time based on engineering approaches. And it is expected that this thesis can contribute to plan freight policies which can improve to have competitive power in the level of a company or nation by reducing logistic costs.

• Journal of Korean Society of Transportation
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• v.27 no.1
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• pp.129-141
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• 2009

Intermodal freight transportation is defined as the movement of freight from origins to destinations by two or more transportation modes. When implemented in hub networks, it could enhance the efficiency of the networks because consolidated flows are transported by more suitable modes and technologies. In spite of this advantage, the intermodal hub network design problem has received limited attention in the literature partly because of the complex nature of the problem. This paper aims to develop an optimization model for designing intermodal hub networks with sin91e allocation strategy. The model takes into account various cost components of intermodal hub networks including transportation, stationary inventory, and service delay costs. Moreover, using transport frequency variables, it is capable of endogenously determining the transportation economies of scale achieved by consolidation of flows. As such, the model is able to realistically represent the characteristics of intermodal hub networks in practice. Since the model Is a complicated nonlinear integer programming problem, we perform model simplification based on the analytical study of the model, which could facilitate the development of solution algorithms in the future. We expect that this study contributes to the design of intermodal hub networks as well as to the assessment of existing logistics systems.