• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.3
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• pp.47-65
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• 2014

VMS(Variable Message Sign) helps drivers to choose their path to destinations on roadways. Some types of VMS often provide traffic information with clearly visible and comprehensible graphical route diagrams. Currently many diagramed types of VMS are installed on urban arterial and highways. This type of VMS surely enhances drivers' ability to comprehend traffic route information while they are driving on the roadway. Nevertheless, some of them are presented with so much information and design elements and they sometimes lead to decline of drivers' comprehensible level for traffic information. Drivers would fail to decide their preferable route in this state of information overflow. The purpose of this paper is to develop a drivers preference model for effective design principle including size and height of displaying font, and the amount of information in the route diagram considering driving speed, sex and age of the driver. This model is developed using structural equation modeling techniques. This model considers driver's emotional factor and, human factor and design component of route diagram. To collect data, we built driving simulator which is able to replicate real driving condition. 72 people who participated in the simulation were selected considering gender and age. The developed model showed that the amount of information, and visibility are more influential factors to the drivers' preference of the route diagram on VMS than design elements such as the shape and the font of the diagram.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.53-62
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• 2011

Although the demand of Variable Message Sign(VMS) has become pervasive in fulfilling the ITS policy, there are still several unsolved problematic issues. The most critical ones of them are inequality and inefficiency of providing traffic information. This paper proposes the Infra-free Variable Message Sign in order to provide useful informations such as road condition, weather, and traffic of the area, where constructing the infrastructure of communication and power supply is relatively very hard. First of all, the characteristics of infra-free Variable Message Sign are studied and analyzed in deep because of differences between normal Variable Message Sign and Infra-free Variable Message Sign in the configuration and the operating method due to the nature of the Infra-free Variable Message Sign. Futhermore, for effective power management of operating Infra-free Variable Message Sign with limited power acquired through stand-alone PV system, new battery connection structure and dynamically variable power managements for the differently shown messages on Variable Message Sign are proposed. The proposed structure in this paper can be applied to not only power management for Infra-free Variable Message Sign but also power management for the various applications using parallel connection battery system.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1650-1651
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• 2011

본 논문에서는 가변안내표지판(VMS)용 멀티-채널 LED Driver IC를 설계 연구 하였다. 설계한 LED Driver IC의 채널 수는 96 채널을 기본으로 하여 여분의 64채널을 추가로 구성하였다. VDD는 동작 환경에 따라 사용할 수 있게 12V, 6V, 3.3V로 구성하였다. 각 채널당 전류는 20mA로 일정한 전류가 흐를 수 있도록 하였다. 온도 변화에 따른 전류 변화로 인한 LED 휘도특성 변화를 줄이기 위해 트랜지스터를 여러단으로 쌓아 회로를 구성하였으며 내부 회로에 PTAT과 Bandgap Reference를 이용하여 트랜지스터에 안정적인 전원이 공급될 수 있게 구성하였다. 본 논문에 사용된 공정은 동부 0.13um 공정으로 최대 3.3V까지 사용할 수 있지만 12V및 6V에도 사용할 수 있게 트랜스지터를 쌓는 회로를 구성하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.6
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• pp.54-67
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• 2013

The main purpose of this study is to analyze the diversion rate by the levels of delay and the types of display. For this study, we developed the logit model by analyzing the result of SP survey of drivers who have driver's licence after manipulating a virtual driving simulator. The result of analysis was that the types of display was not statistically significant to the diversion rate. On the other hand, the levels of delay was very meaningful factor with the diversion rate. When the main road was flowing smoothly, drivers started to detour at the levels of delay 125% under the traffic free flow state. Similarly, when the levels of delay got worse, the diversion rate kept the same percentage as it was at the levels of delay 125% state which represented a smooth road condition. Likewise, when the main road's traffic flow was slow, drivers appeared to make detours at the same state of the levels of delay 125%. It was found that as the levels of delay got worse, the diversion rose higher than the diversion rate at the condition of slow traffic flow situation with the levels of delay 125%. The result of this study suggests the criterion of drivers detour point. For the conclusion, the result of study would be a reasonable reference for establishing transportation strategies by reflecting drivers' detouring property and would improve the efficiency of traffic flow.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.8
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• pp.1140-1147
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• 2012

This paper proposes the power management technology for stand-alone PV system to extend installation environment and coverage. The proposed power management technology in this paper can protect battery safeness from overcharge/discharge with keeping the proper SOC(State of Charge) and extend using time of system through estimation of operating power. The proposed power management technology in this paper is applied to Infra-free Variable Message Sign. And performance of power management technology in this paper was verified using simulation scenario.