• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.926-931
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• 2004

In this paper, we proposed security management architecture that combines programmable network technology and policy based network management technology to manage efficiently heterogeneous security systems. By using proposed security management architecture, a security administrator can manage heterogeneous security systems using security policy, which is automatically translated into a programmable security policy and executed on programmable middleware of security system. In addition, programmable middleware that has the features of programmable network can reduce excessive management traffic. We showed that the programmable middleware could reduce the load of management traffic by comparing processing time between the proposed architecture and PBNM architecture.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.5
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• pp.1101-1105
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• 2013

Due to underutilization of spectrum under the current static spectrum management policy, various kinds of dynamic spectrum access strategies have appeared. Myopic policy is a simple policy with reduced complexity that maximizes the immediate throughput. In this paper, the distribution of its medium access delay is evaluated under saturation traffic conditions. Using the distribution of the medium access delay, we also evaluate its system delay under non-saturated traffic conditions.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.3
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• pp.14-24
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• 2006

There are many problems and limits in equipments being used for traffic-volume analysis in the country. And traffic-volume information acquired through existing equipments is not provided in real-time. In the case of urban, there are limits on guarantee of trust on comprehending a appropriate road-volume because of difficulty on analyzing traffic-volume density and time series. And it is difficult to applicate in deciding a road policy as existing equipments don't provide the control information of traffic-flow. Therefore, it is necessary to build a road-flow policy rapidly and accurately through the road-flow information that analyze post-processed statistics data using traffic-flow investigation based on real time. In this study, we developed TICS(Traffic Information Collection System) based on GPS which could transmit traffic information transformed from car location information to traffic control center. And we developed TCS(Traffic Control System) based on Web GIS, which could manage and analyze transmitted traffic information, and it could offer handled road-flow information to Web-site in realtime.

• Transportation Technology and Policy
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• v.8 no.4
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• pp.77-85
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• 2011

• Transportation Technology and Policy
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• v.7 no.1
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• pp.93-102
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• 2010

• Transportation Technology and Policy
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• v.7 no.5
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• pp.99-103
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• 2010

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.3
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• pp.75-89
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• 2020

This study was conducted to investigate researches related to tourism transport conducted in Korea and to discover new complementary research projects based on this. Forty cases were reflected in the study, including 28 academic papers and 12 policy studies. Based on the characteristics of tourism transport and cases of prior research, this study divided the field of tourism transport research into three ranges: traffic mode choice for tourism, information for tourist traffic and support policy for tourist traffic etc. In particular, mode choice for tourist traffic was divided into four sub-ranges, reflecting the importance of tourist traffic and the weight of research cases. As a result of the study, it was found that there were not many cases of research on tourism transport, and the research cases were concentrated on the mode choice for tourist traffic. To complement this, this study proposed 10 new research projects in 3 ranges. This is a result of reflecting changes in tourist demand and tourism trends. In addition, a new research field was proposed to seek the connection between transport facilities supply and tourist demand.

• Proceedings of the Korea Port Economic Association Conference
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• 2007.07a
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• pp.255-270
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• 2007

In North-East Asia, Port traffic in Asia-North America sea route has been rapidly increasing due to economic growth in China and ASEAN. Furthermore, the major shipping companies directly call at northern chinese ports like Qingdao, Dalian and Tianjin without passing through Korean ports on Asia-North America sea route. To acquire a port traffic and develop a hub port, governments in North-East Asia have intensively invested in the development of port. Therefore, Busan new port and Gwangyang port have been developed in Korea. According to the medium-long term development planning, the port should give a enormous budget investment for the port facilities construction. So the inaccurate estimation may lead to the unreasonable port development policy. Firstly, based on the estimation of Chiang Bong-Gyu & Yang Hang Jin(2005), this study gave a comparison with the estimation of Ministry of Maritime Affairs and Fisheries(2001) and OSC/Glori(2005). Secondly, taking into account the influence factors for port traffic, this study made an estimation of port traffic for Busan new port. On the basis of this estimation, this study is compared with the estimation of Ministry of Maritime Affairs and Fisheries(2001) and OSC/Glori(2005). In conclusion, in case of the development of Busan new port, based on the estimation of Ministry of Maritime Affairs and Fisheries(2001), this study should the high possibility that the Busan new port will be serious lack of the port facilities in the year of 2011. And according to the OSC/Glori(2005)'s estimation result, there is a lack of the port facilities, though we have modified the port investment plan.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.11
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• pp.4268-4289
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• 2020

Advanced traffic signal timing method plays very important role in reducing road congestion and air pollution. Reinforcement learning is considered as superior approach to build traffic light timing scheme by many recent studies. It fulfills real adaptive control by the means of taking real-time traffic information as state, and adjusting traffic light scheme as action. However, existing works behave inefficient in complex intersections and they are lack of feasibility because most of them adopt traffic light scheme whose phase sequence is flexible. To address these issues, a novel adaptive traffic signal timing scheme is proposed. It's based on actor-critic reinforcement learning algorithm, and advanced techniques proximal policy optimization and generalized advantage estimation are integrated. In particular, a new kind of reward function and a simplified form of state representation are carefully defined, and they facilitate to improve the learning efficiency and reduce the computational complexity, respectively. Meanwhile, a fixed phase sequence signal scheme is derived, and constraint on the variations of successive phase durations is introduced, which enhances its feasibility and robustness in field applications. The proposed scheme is verified through field-data-based experiments in both medium and high traffic density scenarios. Simulation results exhibit remarkable improvement in traffic performance as well as the learning efficiency comparing with the existing reinforcement learning-based methods such as 3DQN and DDQN.

• Transportation Technology and Policy
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• v.1 no.2
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• pp.71-84
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• 2004

In Europe, London, Edinbergh, Copenhagen has adopted the traffic congestion charge system, and now the Stockholm City Council started the implementation of a similar system of its own. According to the Swedish National Road Administration, the system implementation starts in 2004 and will be completed by 2005, and so starting 2006, this charge system will be running as planned. Unlike the system of London, that of Stockholm charges the drivers differently depending on when to pass a control point, and not only that, the City Council has a plan to adopt the emerging RFID technology. Following is the summary of both technical and policy-wise considerations of the traffic congestion charge system in Stockholm, Sweden.