• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.179-186
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• 2008

It is crucial in traffic flow management to maintain productivity and the traffic stability at the same time especially under congested traffic conditions. This issue has not been explicitly addressed under the intelligent transportation system environments. However, the ubiquitous transportation system environments make it possible to collect the data for each vehicle's position and velocity and to perform more sophisticated traffic flow management at individual vehicle or platoon level through V2V and V2I communications. In this paper, a preventive traffic flow management scheme is proposed, in which the objective is to maintain traffic flow stability while the productivity of the system is not decreased. The management scheme is proposed based on Greenshield's model because it is simple and easy to handle. It is considered that further research should be performed to evaluate the various traffic flow models.

• Transportation Technology and Policy
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• v.8 no.3
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• pp.51-60
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• 2011

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.6
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• pp.35-41
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• 2010

The ubiquitous-transportation sensor network (u-TSN) system is a next generation transportation system that provides traffic information through analysis and processing periodic information from vehicles. In this paper, we propose the adequate transmission scheme from vehicles for collecting vehicular information. The conventional scheme is transmitting each vehicle information every 0.1s. A variable transmission period scheme is proposed in this paper according to vehicle speed. The proposed and conventional schemes are compared with computer simulations.

• Journal of Korean Society of Transportation
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• v.28 no.4
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• pp.167-175
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• 2010

The ubiquitous transportation system environments make it possible to collect each vehicle's position and velocity data and to perform more sophisticated traffic flow management at the individual vehicle or platoon level through vehicle to vehicle (V2V) and vehicle to infrastructure (V2I) communication. It is necessary to develop a traffic flow management scheme to take advantage of the ubiquitous transportation system environments. This paper proposes an algorithm to advise the optimal speed for each vehicle according to the traffic flow condition. The algorithm aims to stabilize the traffic flow by advising the equilibrium speed to the vehicles speeding or crawling under freely flowing condition. And it aims to prevent or at least alleviate the shockwave propagation by advising the optimal speed that should dampen the speed drop under critical flow conditions. This paper builds a simulation testbed and performs some simulation experiments for the proposed algorithm. The proposed algorithm shows the expected results in terms of travel time reduction and congestion alleviation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.225-231
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• 2013

A bird's-eye view is an elevated view of an object from above, with a perspective as though the observer were a bird, often used in the making of blueprints, floor plans and maps. It can be used under severe weather conditions when visibility is poor. Under low visibility environments, drivers can communicate each other using V2V communication to get each vehicle's status to prevent collision and other accidents. Ubiquitous transportation sensor networks(u-TSN) and its application are emerging rapidly as an exciting new paradigm to provide reliable and comfortable transportatione services. The ever-growing u-TSN and its application will provide an intelligent and ubiquitous communication and network technology for traffic safety area.

• Journal of Intelligence and Information Systems
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• v.16 no.1
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• pp.57-69
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• 2010

The ubiquitous transportation system environments make it possible to collect each vehicle's position and velocity data and to perform more sophisticated traffic flow management at individual vehicle or platoon level through V2V and V2I communication. It is necessary to develop a new data processing methodology to take advantage of the ubiquitous transportation system environments. This paper proposed to build 3-dimension data profiles to maintain the detailed traffic flow information contained in the individual vehicles' data and at the same time to keep the profiles from the meaningless fluctuations. Also methods to build the platoon profile and the shock wave speed profile are proposed, which have not been possible under ITS(Intelligent Transportation System) environments.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.5
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• pp.36-46
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• 2011

It is thought traffic flow management under the ubiquitous transportation system has great potential in view of individual vehicle data availability and V2V, V2I two-way communication environments. However, it is expected that deployment of the ubiquitous transportation system takes some time. Therefore it is necessary to evaluate the feasibility of the algorithm under the ITS environment. The speed management algorithm proposed in the previous research is revised to fit for the ITS data collection and information provision environment. And the feasibility of the algorithm is evaluated through simulation experiments.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.8 no.3
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• pp.122-131
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• 2009

Ubiquitous-Transportation sensor network is able to realize a vehicle ad-hoc network. Since there are some problems in an existing ITS system, the new technology and traffic information strategies are requirements in this advanced system, u-TSN. The purposes of this paper is to introduce the components on u-TSN system, establish new traffic strategies for this system, and then evaluate these strategies by making a comparative study of ITS and using micro traffic simulator, AIMSUN. The strategy evaluated by AIMSUN is position-based multicast strategy which provides traffic information to vehicles using V2I (vehicle to Infrastructure) communication. This paper focuses on the providing real-time route guidance information when congestion is occurred by the incidents. This study estimates total travel time on each route by API modules. Result from simulation experiments suggests that position-based multicast strategy can achieve more optimal network performance and increased driver satisfaction since the total accumulated travel times of both the major road and the total system on position-based multicast strategy are less than those on VMS.

• Proceedings of the Korean Institute of Building Construction Conference
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• v.y2004m10
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• pp.67-70
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• 2004

The ubiquitous computing environment is widely expanded in almost all industries such as transportation. physical distribution, manufacturing, communication, tourist industry, financial business, and so on. But the construction industry is not well applied yet. Thus this study investigate the ubiquitous computing environment and propose a way for applying this technology to the construction industry. To achieve this aim, this study consider about a instrumentation management of retaining wall system in earthmoving operations, and suggest the ubiquitous system configuration to measure the variance of retaining wall. Through this system, the efficiency of the instrumentation management of retaining wall will be improved.

• Spatial Information Research
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• v.14 no.4 s.39
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• pp.421-431
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• 2006

Nowadays, the importance of safety monitoring for facilities is increasing. Therefore, the introduction of ubiquitous technology to replace the existing manually-operated methods is required. In this study, a web-based GIS system that provides monitoring information of bridges in real-time for the application of a bridge management system through the use of ubiquitous technology is constructed. Particular attention is given to the effective interconnection of bridge monitoring information and bridge management system and, through a ubiquitous environment, how to connect this with the UFID and the GIS-based bridge management system (BMS) operated by the Ministry of Construction and Transportation. In addition, data expression methods are also suggested that state the detailed locations and attributes of structures in bridge management by using GIS.