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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Korean Society of Transportation
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Journal DOI :
Korean Society of Transportation
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Volume & Issues
Volume 13, Issue 4 - Aug 1995
Volume 13, Issue 3 - Jun 1995
Volume 13, Issue 2 - Apr 1995
Volume 13, Issue 1 - Feb 1995
Selecting the target year
The Assessment of TRACS(Traffic Adaptive Control System)
Journal of Korean Society of Transportation, volume 13, issue 1, 1995, Pages 5~33
This paper addresses the outlines of the traffic signal timing principles engaged in TRACS and the results of field test. Research team, encompassing research institute, university, and electronic company, conducted the three-year project for developing the new system, named TRACS(Traffic Adaptive Control System). The project was successfully completed in 1994. TRACS aims at accomplishing the objectives of better traffic adaptability and more reliable travel time prediction. TRACS operates in real-time adjusting signal timings throughout the system in response to variations in traffic demand and system capacity. The purpose of TRACS is to control traffic on an area basis rather than on an isolated intersection basis. An other purpose of TRACS is to provide real-time road traffic information such as volume, speed, delay , travel time, and so on. The performance of the first version of TRACS was compared to the conventional TOD control through field test. The test result was promi ing in that TRACS consistantly outperformed the conventional control method. The change of signaltiming reacted timely to the variation of traffic demand. Extensive operational test of TRACS will be conducted this year, and some functions will be enhanced.
A Study on the Typical Patterns of Traffic Accident Lots and Establishment of Acknowledgement Model of their Causes and Preference Model to Decrease Traffic Accidents
Journal of Korean Society of Transportation, volume 13, issue 1, 1995, Pages 35~62
Traffic has a very important function but has caused such social problems as traffic congestion parking and traffic accidents in metropolitan areas. It is difficult to examine the causes of traffic accidents related to human life, which occur by human, vehicle and environmental factors. But human factor is the only measure requlating these factors together an analyzing factors influencing establishment of counterplan of traffic accidents. Consequently , this study employs the principal component analysis and stepwise multiple regression analysis to estimate the characteristics and influential factors of traffic accidents and defines the typical patterns of happening lots of traffic accidents. Accordingly, this study establishes an acknowledgement model of the causes and preference model of the counterplan of traffic accidents using Multi-Dimension Preference(MDPREF) method.
A Study on Development of Forecasting Model for Traffic Accident in Chung-Chong Region
Journal of Korean Society of Transportation, volume 13, issue 1, 1995, Pages 63~82
This paper deals with the forecasting model for traffic accident. Its objective is to develop the appropriate model to project the accident of Chung-Chong Region. Two types of models between motorization (M) and personal hazard (P) are tested : One is inverted-U (bell type) curve and the other is increasing (or decreasing) curve. The statiscal and sensitivity analyses show that exponential model (type III) and multiplicative model (type II) are well fit to the given cross-sectional and time-series accident data. The model projects that the fatality per 100, 000 persons of Chung-Chong region, when the motorization level (M) is 0.2, would be in the range between 18 and 77 persons. The paper concludes that the accident level is the function of motorization and the result of implementing the safety policy of a region.
Application of a Linear Programming in a Taxi Dispatching System
Journal of Korean Society of Transportation, volume 13, issue 1, 1995, Pages 83~94
Many taxis called "Mobum" in Seoul are empty and waiting along the curb during the day time. However, it is almost impossible for elderly and handicapped people, and women carrying babies to use them .It is because they can not serve passengers who request services by phone. If taxis, expecially "Mobum" taxis which offer high quality services, can be dispatched based on requests by phone, not only elderly and handicapped people but also auto commuters will easily call and use them. This paper shows a taxi dispatching system. The system minimizes the total empty vehicle hours under given number of empty vehicles and passengers and their locations. As a result, the system maximizes number of services and revenue under given number of taxis. The system adopts a well -known linear programming model and the model can fast and easily be solved by PC level linear programming packages. Also, practical solutions of the system's constraints such as size and travel time forecast are discussed.ecast are discussed.
Development of a neural-based model for forecating link travel times
Journal of Korean Society of Transportation, volume 13, issue 1, 1995, Pages 95~110
n this research neural -based model was developed to forecast link travel times , And it is also compared wiht other time series forecasting models such as Box-Jenkins model, Kalman filter model. These models are validated to evaluate the accuracy of models with real time series data gathered by the license plate method. Neural network's convergency and generalization were investigated by modifying learning rate, momentum term and the number of hidden layer units. Through this experiment, the optimum configuration of the nerual network architecture was determined. Optimumlearining rate, momentum term and the number of hidden layer units hsow 0.3, 0.5, 13 respectively. It may be applied to DRGS(dynamic route guidance system) with a minor modification. The methods are suggested at the condlusion of this paper, And there is no doubt that this neural -based model can be applied to many other itme series forecating problem such as populationforecasting vehicel volume forecasting et .
An Analytic Study on Optimal Bus Size
Journal of Korean Society of Transportation, volume 13, issue 1, 1995, Pages 113~123
An Empirical Analysis of Estimated Delay Time Delay Time at Signalized Intersections
Journal of Korean Society of Transportation, volume 13, issue 1, 1995, Pages 125~152
The purposes of this study are twofold ; (1) to investigate the accuracy of estimation power of the individual models. such as those of Highway Capacity Nanual (HCM), Korea Highway Capacity Manual (KHCM), and NationalCooperative Highway Research Program(NCHRP) Report339 ; and (2) to develop an adjusted delay model which can be applied to the signal control system in urban areas. The study is mainly focused on four subjects related to the research purposes, which are as follows ; (1) characteristecs of exsisting delay models ; (2) inherent problems in exsisting delay models : (3) validation of the proposed model by the comparison of observed delay with estimated delay :and (4) a method which can be applied to develop an appropriate delay model for actrual signal control systems by the adjusted fact of the proposed model.
A Studyon Implementation of TPBS (Transportation-planning Programming Budgeting System)
Journal of Korean Society of Transportation, volume 13, issue 1, 1995, Pages 153~165
The budget management in Korea is one-year budget system which is just following int he steps of last years budget plan. This system towards traditional item-by-item and restriction-centered budget system. The budget distribution without establishing and considering rational policy goals and directions have brought inefficient resource allocations. In order to promote the implementation of transportation planning, there are some alternatives like introduction of top-down planning system preparing for the provincial self-government era. In this study, the most efficient alternatives to promote the existing management system is referring by foreign countries transportation planning examples(BVWP system in Germany). First of all, mid-long term transportation and budget planning should be established and then make decisions of resource availability and allocation. In order to provide ration budget planning, introduction of Transportation Planning Programming Budget System(TPBS) has been judged as one of the method of unifying the sysematic transportation improvement planning and budgeting. All transporation planning and related activites can not be expressed in quantity and due to the limitation of excessive cost of analyzing transportation planning and ranking priority, here after, the continuous study to minimize the evaluation cost and introduction of TPBS should be done.
The Development of Capacity Estimation Methods from Statistical Distribution of Observed Traffic Flow
Journal of Korean Society of Transportation, volume 13, issue 1, 1995, Pages 167~183
The objective of study is to evaluate highway capaicty estimation alternative and to develop capacity from statistical distribution of observed traffic flow. Speed-Volume relation is analyzed from vehicle's headway distribution eliminating the long headway by confidence intervals 99%, 95%, 90%. Capacity estimate alternatives were evaluated from 95% , 90%, 85% level of cummulative distribution of observed hourly traffic flow adjusted to confidence intervals. The result of investigation revealed that maximum hourly rate of flow is 2, 130pcu at confidence interval of 995, 2, 233pcu at 95%, 2, 315pcu at 90% respectively. Compared to the capacity of 2, 200pcu per hour per lane used in HCM and KHCM(Korea Highway Capacity Manual), capa챠y appears to correspond to confidence interval of 95%. Using the traffic flow rate at confidence interval of 95% the maximum hourly flow rate is 2, 187pcu at 95% of cummulative volume distribution, 2, 153pcu at 90%, 2, 215pcu at 85%. The study suggests that raional capacity esimation alternative is to take the 95% of cummulative distribution of observed hourly traffic flow at 95% confidence headway interval eliminating 5% long headway.(i.e. 95-95 rule)
A Microscopic Traffic Simulation Model for Urban Network Performance Evaluation
Journal of Korean Society of Transportation, volume 13, issue 1, 1995, Pages 185~203
The purpose of this paper is to develop a microscopic traffic simulation model which is able to both analyze and the evaluate signlaized urban network and to verify its usefulness in comparison with the other model which has alfeady been released. This simulation model adopts the General Motor's 5th model for car-following and introduces an unique lanechanging rule using acceptable gap. It analyzes single and dual-ring signal phases and generates detector information . So it could be applied to dynamic route guidance systems as wel as real time signal control systems. The results derived from Netsim and the observed data from the real network have been used to test the validit of the proposed model. The result of the test has shown that there are no significant differences between the NETSIM model and the proposed model in estimating travel speed and stopped delay. In optimum offset estimatin , it has shown the same results with NETSIM. the measure of effectiveness , however, derived from this model is slightly better than that of the real network situation. This may be due to the fact that the proposed model does not take into account side frictions from interferences and obstacles.