• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.65-76
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• 2018

This study aims to evaluate the legibility distances of variable speed limit sign(VSL) for different sizes, luminances, and fog conditions through a field experiment. For this, extensive fog simulated environment has been constructed, and legibility distances are tested and recorded among test subjects for different luminances and sizes of VSL in control. Results showed that legibility distance increased as the size of VSL increased in the given illumination conditions, but it was not an exact linear trend. The size was also an important factor for determining legibility distance as the fog density increased, especially heavy fog conditions. In addition, the legibility distance also increased as the given illumination levels of VSL improved.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.1
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• pp.166-175
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• 2017

Hazardous volcanic activity will continue to occur in the ring of fire, a major area in the basin of the Pacific Ocean where a large number of earthquakes and volcanic eruptions occur. and, because of rising populations, development pressures, and expanding national and international air traffic over volcanic regions, risks to life and property through exposure to volcano hazards continue to increase. During an eruption, volcanic contamination can reach and exceed the cruising altitudes of turbine-powered aircraft, among others, within minutes and spread over vast geographical areas within a few days. Volcanic ash can affect the operation of aircraft at aerodromes. Volcanic ash deposition at an aerodrome, even in very small amounts, can result in the closure of the aerodrome until all the deposited ash has been removed. In this study, air traffic information framework is presented along with algorithms to define affected routes, waypoints and airports using GIS geometry analysis.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.1
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• pp.1-13
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• 2017

A national highway takes on an arterial roadway role between regions. It's traffic volume of minor approach is very lower than mainline because most of the traffic of national highway consists of through traffic. This means an actuated signal operation is more efficient on the national highway than pre-timed signal. actuated signals have detections on some or all movements except the mainline. In spite of these effects have been evaluated in previous studies, widespread propagation of actuated signal operation has not made so much in Korea. Because there are so many problems to use actuated signal as it is in side of roadway facilities. In this study, improved a actuation system for the national highway and evaluated it with field implementation.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.5
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• pp.1-11
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• 2017

Expressway network which plays an important role on land transportation system, have been developing quantitatively and qualitatively with $7{\times}9$ structure. To cope with complex geometric condition, guidance lane marking has been installed to induce safer lane-changing maneuver. However, there is no standard on guidance lane marking and its effectiveness is also verified with limited scope. The major purpose of this research is to clarify its effectiveness in terms of driving safety aspect using virtual driving simulator and to suggest standard on the proper length. To carry this out, preference data from subjects was collected and lane-changing pattern within virtual driving environment was investigated. In addition, in order to quantify the level of comfort, Electroencephalogram data was collected and validated using statistical test. Finally, it is expected that this research can be used to establish standard on guidance lane marking.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.5
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• pp.85-95
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• 2017

This study aims to identify the throw distance in terms of truck weight, bumper height, and speed in a truck and pedestrian collision, and to propose a model for throw distance estimates. For this purpose, a simulation analysis is performed using the PC-crash program with the following experiment conditions: Truck weight of 5t, 15t, and 25t, Bumper height from 0.3m to 0.6m by 0.1m, and speed from 10km/h to 100km/h by 10 km/h. Experimental results show that the truck speed and bumper height are found to be significant factors for pedestrian throw distance, but truck weight is not a significant factor. Also, a regression model is developed for pedestrian throw distance estimate from the multiple regression analysis. The adjusted $R^2$ value of the model is 93.3%, which is very good explanatory power.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6B
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• pp.527-533
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• 2006

In this paper, we analyze the performance of MAC (Media Access Control) layer in DSRC (Dedicated Short Range Communication). It will be widely applied for ITS (Intelligent Transportation System) services; for example ETC (Electric Toll Control), BIS (Bus Information System) etc., needed to small packet size. But If ITS service is evolving to advance ITS, ADIS (Advanced Driver Information Systems) and AVHS (Advanced Vehicle Highway System) etc, be needed larger packet size. In the future, it may offer more various services such as traffic information, collection, and multimedia information. There are two kind of physical media, IR(Infrared) and RF(Radio frequency). And each system has their own protocol that is adaptive in special characteristics of physical medium for using efficiently limited radio resources. In this paper, we analyze the special characteristics of each system. And we study practical use of some related services expected to be used in the near future, by analyzing the transmission efficiency in each DSRC system.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.2
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• pp.14-26
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• 2009

This study presented a novel method to estimate travel times under incident conditions. Predictive travel time information was defined and evaluated with the proposed method. The proposed method utilized individual vehicle speeds obtained from global positioning systems (GPS) and inter-vehicle communications(IVC) for more reliable real-time travel times. Individual vehicle trajectory data were extracted from microscopic traffic simulations using AIMSUN. Market penetration rates (MPR) and IVC ranges were explored with the accuracy of travel times. Relationship among travel time accuracy, IVC ranges, and MPR were further identified using regression analyses. The outcomes of this study would be useful to derive functional requirements associated with traffic information systems under forthcoming ubiquitous transportation environment

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.2
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• pp.53-59
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• 2009

Integrating a field of transportation and IT is becoming a novel solution to social and economic problems which was previously focused on the investment in infrastructures. It also created new areas of industry such as ITS and telematics. Especially, vehicle communication is being considered very important and DSRC is also important in the field of rational ITS in recent. DSRC OBE has come into wide use through ETCS. In the field of traffic signal control, the research to implement an optimal traffic signal control system using a real-time information of good quality is being carried out and also the study of WISDOM was successfully completed. This paper shows the development of Dynamic-Dilemma zone warning service utilizing WISDOM and the evaluation of a reliability and a practicality through the field test. While the proposed Dynamic-Dilemma warning system transmits an information of signal time optimized by WISDOM, the OBE which receives this information makes dilemma zone based on its location and speed and gives warning to a driver.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.4
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• pp.54-67
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• 2016

All roundabouts are designed based on "Roundabout Design Guideline, Ministry of Land and Transportation, 2014" in Korea. The guideline also provides the traffic volume criteria to convert from signalized intersections to roundabouts. While the criteria are based on capacity of roundabouts, left-turn ratio and the number of lane on approaches are not considered to calculate the capacity of roundabouts. Therefore it is difficult to apply the traffic volume criteria in the real world. In this study, we studied the impact of left-turn ratio and the number of lane on approaches into capacity of roundabouts using micro-simulation. It was found that the capacity of roundabouts is changed according to left-turn ratio and the number of lane on approaches.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.4
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• pp.56-65
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• 2013

The word is endeavoring to reduce greenhouse gases with the sense of crisis caused by the continuous climate change. As a method to decrease greenhouse gases, motors driven by fossil fuels are being substituted by EV in the field of transportation. Meanwhile, for the spread of EV, charging installations are divided into general charging type and quick charging type. Also, charging amount and time are main factors to decide charging pay. But, because the opportunity coast for the charging time varies depending on the private situations, it is very important to understand exact phenomenon for the spread of EV charging installations and charging pay policy. Therefore this paper suggested the choice model of charging installation and time value in various situations by using Logit model to make clear the relationship between a choice of charging installation, charging time and willingness to pay for charge.