• Journal of Korean Society of Transportation
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• v.25 no.3
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• pp.99-109
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• 2007

Variable message signs (VMS), which are used for providing real-time information on traffic conditions and accident occurrences, are one of the important components of intelligent transportation systems VMS messages need to meet human factor requirements: messages should be readable and understandable while driving. Lab-controlled experiments on VMS messages were conducted to obtain useful data for analyzing drivers' responsive characteristics for VMS messages. Binary logistic regression (BLR) modeling techniques were applied to explore the relationships among drivers' message perceptions, message reading time, and amount of VMS messages. Probabilistic outcomes of the proposed BLR-based perception model could be greatly utilized to design VMS messages considering drivers' legibility performance. The major contribution of this study is to develop invaluable statistical models that can be used in designing VMS messages more effectively from the human factor point of view. The results could be further applied to establish the scheme of VMS message phase and duration.

• 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2D
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• pp.227-235
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• 2011

At present, the characteristics of drivers are not properly considered when informations are provided via VMS even though the Variable Message Signs(VMS) are one of the key information provision medias on the roads. In this study, the driver's psychological response(stress index) was evaluated using a driving simulator for the position of the VMS provided, the contents of the VMS provided, the size of characters on VMS, and types of VMS expression. It was appeared that the stress is the least when the position of the VMS provided 1.5km proceeded from exit, the contents of the VMS provided are time information and types of VMS expression are character form respectively and the size of characters on VMS is appeared not important. In addition, the change of the users' satisfaction level was measured when increasing the numbers of VMS on unit distance and the size of characters. The size of character was almost not effected in similar to the result of stress index and the satisfaction level increased when increasing the number of VMS on the unit distance. The results of this research can be utilized as basic data for the ITS system design and operation stages.

• Journal of Multimedia Information System
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• v.1 no.2
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• pp.95-100
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• 2014

Variable message signs (VMS) have the different sizes and a specific type according to the city scene and it has to be displayed by different message on the display panel in real-time. And VMS manufacturers must produce the different products in order to give a customized product to each order. In addition that, they should test and check the correct operation to each VMS product using the different message frame. That is very time and workers consuming and VMS emulator with an automatic variable message generator system is necessary. Also, the automatic message generator system is needed to real-time scheduling in order to display the message on the VMS panel like real world. In this paper, we design and implement the VMS emulator embedded the automatic message frame generator system with real-time scheduling which can set several parameters easily on the windows dialog.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3D
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• pp.409-416
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• 2006

Real-time traveler information disseminated through Variable Message Signs (VMS) is known to have effects on driver route choice decisions. In the past, many studies have attempted to optimize the system performance using VMS message content as the primary control variable of driver route choice. This research proposes a VMS information provision optimization model which searches the best combination of VMS message contents and display sequence to minimize the total travel time on a highway network considered. The driver route choice models under VMS information provision are developed using a stated preference (SP) survey data in order to realistically capture driver response behavior. The genetic algorithm (GA) is used to find the optimal VMS information provision strategies which consists of the VMS message contents and the sequence of message display. In the process of the GA module, the system performance is measured using micro traffic simulation. The experiment results highlight the capability of the proposed model to search the optimal solution in an efficient way. The results show that the traveler information conveyed via VMS can reduce the total travel time on a highway network. They also suggest that as the frequency of VMS message update gets shorter, a smaller number of VMS message contents performs better to reduce the total travel time, all other things being equal.

• Journal of the Korean Society of Food Culture
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• v.25 no.2
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• pp.117-125
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• 2010

We surveyed 821 children (ages 12-15 y) in Daejeon city and Cunngcheong province, Korea for their use of vitamin mineral supplements (VMS), either over-the-counter drugs and/or health functional foods (HFF). We also considered the significant variables of VMS use, including demographic characteristics, health-related variables, eating habits and nutritional beliefs of VMS by subjects. The frequency of VMS use was 24.8% and, in comparison to counterparts, it was higher in subjects attending middle school (p<0.001), in those living in a large city (p<0.001), in those with a high monthly family income (p<0.05), and in those with high concerns about school performance by parents (p<0.01). Selfhealth concerns by subjects (p<0.05) and concerns about health of offspring by parents (p<0.01) were higher in users than in nonusers. Eating habits of subjects did not affect the use of VMS. Users had a more positive view concerning the potential health benefits of VMS than did nonusers (p<0.05). Most users took VMS when they were healthy (78.9%) and expected 'disease prevention and health maintenance' (44.6%). However, most users did not feel any special effects from VMS use (58.8%), and they got their information on VMS through family and relatives (53.9%). Users of VMS preferred vitamin C supplements (44.2%) and Ca-supplements (56.9%). Therefore, the results show that VMS use is widely spread among the subjects, and that use of VMS is influenced by multiple variables and subjective criteria. Therefore, practical guidelines on VMS use for children's health and growth should be given through nutritional education.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6D
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• pp.927-933
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• 2006

The Variable Message Signs (VMS) are useful way to reduce the socio-economic costs due to the traffic congestions and delays by providing the information on traffic condition to drivers. This study provided a methodology to determine the locations of VMS's in terms of the minimization of the delay by applying the genetic algorithm. The optimal number of VMS's was also derived by the economic analysis based on the cost and the benefit. The simulation considered the variation of traffic volume, the frequency and duration of the incident, and the traffic conversion in order to reflect the real situation. I've made a scenario to consider traffic volume and incident, and it can undergo through changing different traffic volume and incident in time and days and seasons. And I've comprised two kinds of result, one is based on empirical studies, the other is based on Genetic Algorithm about optimal allocation VMS. This result of using optimal location VMS, reduce total travel time rather than preceding study based on normal location VMS and we can estimate optimal location VMS each one.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.22-32
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• 2010

Increasingly advanced Information Technology (IT) has changed the operator so as to create more diversified and advanced traffic information demand. To deal with the changing demand in private sector, a concept of on-demand traffic information has been rapidly introduced. However VMS, a product of the first generation of ITS, which was designed to provide the unspecified individuals during driving the car with the basic level of traffic information by the public failed to actively change itself in such a changing pattern. This study was intended to describe the VMS system (tentatively, FM-VMS) which was further developed to accommodate the needs favoring the sophisticated PDA with the public role of providing the unspecified individuals with the equal information. FM-VMS introduced in this study is the device designed to transmit the voice and message to the drivers through the radio information device mounted on a car. A core technology is, unlike FM-DARC and RDS, the Water Making technology which directly inserts the digital signal into FM frequency in use. It's been currently used for broadcasting and security purpose. A detection rate as a result of testing FM-VMS system using Water Making technology was 90% or more in voice and message within 20m from test VMS. When a public-developed VMS information could be transmitted using FM frequency to the relatively vulnerable users (vulnerable to traffic information) in voice on a real-time basis to provide the regional traffic information, and furthermore, VMS message could be received through radio liquid using FM frequency only, it would obviously bring about the innovation in ITS as well as pave the way for creating the new added value down the road.

• Journal of Korean Society of Transportation
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• v.29 no.6
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• pp.129-136
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• 2011

Variable Message Signs have been used for providing information on the current traffic conditions. However, it is considered more important to achieve optimal traffic allocation among the alternative routes by strategic VMS information provision. Fuzzy control is very effective and efficient to deal with such systems that are too complex and uncertain to build mathematical models. In this paper, a fuzzy feedback controller for VMS is proposed, whose goal is to achieve the travel time equilibrium between the two alternative routes. The performance of the suggested controller is implemented and examined using MATLAB/Simulink. More robust controller applicable to a real highway network is suggested for the further research.

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.177-183
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• 2002

Current state-of-the-art of VMS control is based upon simple knowledge-based inference engine with message set and each message's priority. And R&Ds of the VMS control are focused on the accurate detection and estimation of traffic condition of the subject roadways. However VMS display itself cannot achieve a desirable traffic allocation among alternative routes in the network In this context, VMS display strategy is the most crucial part in the VMS control. VMS itself has several limitations in its nature. It is generally known that VMS causes overreaction and concentration problems, which may be more serious in urban network than highway network because diversion should be more easily made in urban network. A feedback control algorithm is proposed in this paper to address the above-mentioned issues. It is generally true that feedback control approach requires low computational effort and is less sensitive to models inaccuracy and disturbance uncertainties. Major features of the proposed algorithm are as follows: Firstly, a regulator is designed to attain system optimal traffic allocation among alternative routes for each VMS in the network. Secondly, strategic messages should be prepared to realize the desirable traffic allocation, that is, output of the above regulator. VMS display strategy module is designed in this context. To evaluate Probable control benefit and to detect logical errors of the Proposed feedback algorithm, a offline simulation test is performed using real network in Daejon, Korea.