• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.5 no.3 s.11
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• pp.13-23
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• 2006

The system using UWB is processing brisk study with Bluetooth among the wireless access that is major technology in Telematics. The low complexity and cost for realization is advantage of UWB have communication of high speed. Mamy papers have published on the timing jitter effect on system performance except for the UWB system. In this paper, we analyze the effect of timing jitter on M-ary UWB system using orthogonal Hermite pulse and perform the simulation to show symbol error rate performance. For theoretical analysis, we derive correlation function of orthogonal Hermits pulse with closed form, and as well upper bound of Symbol Error Probability for M-ary orthogonal Hermite pulse system mathematically. It is found that numerical analysis is accurate enough through simulation.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.2
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• pp.34-44
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• 2007

Many urban cities deployed ITS technologies to improve the efficiency of traffic operation and management including a real-time franc control system (i.e., COSMOS). The system adopted loop detector system to collect traffic information such as volume, occupancy time, degree of saturation, and queue length. This paper investigated the applicability of detector information within COSMOS to represent the congestion level of the links. Initially, link travel times obtained from the field study were related with each of detector information. Results showed that queue length was highly correlated with link travel time, and direct link travel time estimation using the spot speed data produced high estimation error rates. From this analysis, a procedure was proposed to estimate congestion level of the links using both degree of saturation and queue length information.

• Journal of Korean Society of Transportation
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• v.29 no.6
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• pp.117-128
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• 2011

In this study, a model is developed to predict emission factors, which aims to objectively evaluate the impact of transport projects on air quality. Two emission prediction models for the years of 2015 and 2030 are developed using the historical trends in vehicle aging and vehicle deterioration factors. The analysis results show that the emission factors under the operating speed of 30km/h for the year 2030 are 5~37% and 2~83% less than those used in the current studies for passenger cars and bus/trucks, respectively. The statistically validated experiment results demonstrate the applicability of the proposed model to evaluation of the impact of transport policies on air quality.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.16 no.2
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• pp.75-82
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• 2004

The changes of sea bottom configuration, which may cause the coastal disasters, have been considered as social problems. It is obvious that the beach deformation is attributable to the sediment transport associated with erosion and acceration. The prediction method and countermeasures for them, however, are not on the level of satisfaction, which indicates that efforts should be made on developing them. In this study, it is found at the groin constructed in Sangju beach on e purpose of beach protection did the aversive function. The reason for this was judged that they accelerated the speed of erosion by increasing the velocity wave-induced current rather than brought storage effect of sediment. Authors found that the storage sediment estimation model by Sonu and Beek(1971) is a useful model at the Sangju beach with the use of topographical survey data from July, 1987 to March, 2003.

• Journal of Korean Society of Transportation
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• v.30 no.3
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• pp.43-55
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• 2012

Bicycle is an environment-friendly transport mode contributing to a more sustainable transportation systems. To innovatively increase the use of bicycle as a significant transport mode, bicycle-friendly roadway environment should be provided. This study proposes a method to evaluate cycling environment based on the analysis of data collected from an specially equipped probe bicycle. The inertial measurement unit(IMU) consisting of a gyro sensor, accelerometer, and a global positioning systems(GPS) receiver was installed on the probe bicycle. Cycling stability index(CSI) and bicycle speed data were used as inputs of the proposed evaluation framework adopting the Fault Tree Analysis, which is a well-known technique for the risk analysis. The outcomes of this study will serve as an intelligent assesment tool for cycling environment.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.3
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• pp.20-29
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• 2010

The variable message sign(VMS) is a representative traffic information service medium which has the largest users and is provided and operated by a governmental agency. In this paper, we focused on psychological responses of individuals who use VMS traffic information in the light of the need for VMS to provide user-oriented service. A total of t재 scenarios were plotted to conduct our experiment on a virtual test track. A stress index analysis on VMS location, the first scenario, showed the lowest stress value at the point of 1.5 kilometers before the exit. A stress index analysis on the contents of VMS information (communication, time, and speed), the second scenario, showed the lowest stress value at time information.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.3
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• pp.59-66
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• 2010

Around a toll plaza, vehicles do such maneuvers as slow down, stop, and speed up to pay their tolls when they use ordinary toll gates. They can be expected more fuel consumptions compared to the vehicles which use the Hi-pass, a Korean type of Electronic Toll Collection System(ETCS). To measure the exact amount of difference between the two gas consumptions, we equipped a test vehicle with a measurement system and constructed a model toll gate on our test field. Through the field tests on fuel consumptions, we could confirm a 36.7 % of energy saving when the test car used the Hi-pass. Then we projected the result on the total traffic volumes which had used national expressway network for five months from January 2009. Projected to the whole traffic, potential cost savings reached 5.34 billion won. We expect this result be frequently mentioned of to prove the fuel efficiency of the Hi-pass system.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.3
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• pp.45-56
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• 2007

Automatic tracking of vehicles is important to accurately estimate the traffic information including vehicle speeds in video-based traffic measurement systems. Because of the limited field of view, the range of visual tracking with a single camera is restricted. In order to enlarge the tracking range for better chance of monitoring the vehicle behaviors, a tracking with consecutive multiple video sequences is necessary. This parer proposes a carefully designed rule-based vehicle racking scheme and apply it for the tracking for two well synchronized video sequences. In the scheme, almost all possible cases that can appear in the video-based vehicle tracking are considered to make rules. Also, the rule based scheme is augmented with Kalman filter. The result of tracking can be successfully used to collect data such as temporal variation of vehicle speed and behavior of individual vehicle behaviors in the enlarged tracking region.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.3
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• pp.67-76
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• 2007

Although Hi-pass have been operated for alleviating traffic congestion and enhancing mobility in expressways since 2000, there is not any standard for safe operation. For that reason, we investigated about tubular markers, which is a typical facility for safety in Hi-pass. Tubular Markers are installed for separating same or opposite traffic flows spatially, supporting the marks at a place which has not only high possibility of accidents but distinguished carefulness of drivers. In this paper, it is noted two considerings; one is prevention of accident from the speed gap of autos and Hi-pass vehicles; the other is guarantee of necessary distance that Hi-pass vehicles could be changes the lanes for off-ramp. Focusing those considerations, it is proposed not only prefer distance of tubular markers, but also fundamental basic subjects. We anticipate that the results of this study would be useful reference in more safe and efficient tollgate operation of Hi-pass.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.1
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• pp.42-54
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• 2018

This study is to establish the traffic volume-based warrants of left-turn lanes in unsignalized intersections based on a risk probability methodology. This study applied a risk probability of a potential rear-end collision between a left-turn vehicle and the immediately following through vehicle. With the shifted negative exponential model and the compound probability theorem, the risk probability can be expressed as the function of directional volumes, opposing volumes and the percentage of left-turns for a two-lane and four-land highway, respectively. The warrants of installing left-turn lanes on unsignalized intersections were developed with the risk probability. The warrants define the total approaching and opposing volumes to encourage a left-turn lane as a function of operating speed, percentage of left-turn, and number of lanes.