• Journal of Korean Society of Transportation
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• v.26 no.1
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• pp.79-88
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• 2008

VMS based dispersion of traffic flows enables to decrease delay and congestion. Such being the case, there has been growing interests in VMS operation strategy. The strategy is based on driver's behavior or diversion rate. However, it was not easy to obtain each in practice. The diversion rate, thus far, was investigated by stated preference analysis or simulators. As an alternative, in this paper, a new method to obtain diversion flow rate was suggested using the toll collection system and freeway traffic management system data. A large gap of diversion rate between stated preference analysis and field survey was observed. Out of surveyed 8 tollgate data, the diversion rate was about 7% and was quite lower compared with that of 21%${\sim}$87% from stated preference analysis or simulators. With this at hand, a more careful information provision strategy should be devised and employed to correctly account this kind of differences.

• 한국ITS학회:학술대회논문집
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• 2008.11a
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• pp.411-417
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• 2008

• Journal of Korean Society of Transportation
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• v.27 no.2
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• pp.57-71
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• 2009

Due to increasing interest in dispersion of traffic flows through providing traffic information, there has been much research of driver behavior and effectiveness of diversion. In this paper the authors intend to analyze how a diversion was determined and its effects through correlation analysis between diversion rates estimated by actual surveys and the traffic conditions. Through speed-flow analysis, the diversion mechanism was found. When travel speed decreased, detour volume increased. Then when the traffic volume was decreased through an increase of diversion and traffic conditions got better, the detour volume decreased again. In addition, the authors found negative correlation between the diversion rate and travel speed through correlation analysis. It shows that there were various relationships between diversion rates and traffic conditions according to congestion level and direction of traffic. Finally, it is suggested that the regression equation for calculating the diversion rate with the traffic flows, travel speed, and travel time as variables has a coefficient of determination of 38.5%. It means that traffic conditions on expressways take about 40% of driver's decision-making for diversion.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.511-513
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• 2011

기존의 Wireless Mesh Network(WMN)에서 제안된 EFMP DSDV 기법은 우회 경로 이후의 잉여 대역폭이 좋지 않을 경우 우회하지 않았을 때보다 성능이 더 좋지 않은 경우가 발생한다. 이 같은 단점을 보완하기 위하여 본 논문에서는 우회 경로 다음 홉 간의 경로 정보인 Hop수와 잉여대역폭에 대한 정보를 획득하여 수식으로 유도된 Bypass값을 통해 각 우회경로의 비교를 제안한다.

• The Korean Journal of Financial Management
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• v.27 no.1
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• pp.121-156
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• 2010

Back-door-listing can be viewed both as M&A and an alternative to IPO. If IPO is an access to the capital market through regulations, back-door-listing would be the way of entering the market through trading. Back-door-listing can be a better choice considering the common wisdom that regulations hinder the functioning of free market system. One would, however, prefer IPO, for the informational asymmetry isless severe in case of IPO. This paper examines if IPO is superior to back-door-listing as to the informational efficiency. The excess buy-and-hold returns of the Kosdaq back-door-listing firms are estimated over the three-year-period since the event. They are compared against the excess buy-and-hold returns of the Kosdaq IPO firms over the same period of time. The results confirm this paper's prediction that IPO should be more information-efficient. Both IPO and back-door-listing firms start with high short-term excess returns and end up with long-term under-performance. However, back-door-listing firms show more significantly damaging long-term results. Furthermore, back-door-listing firms record poorer accounting results over the research period. These results imply that there exists fad at the time of both events and, in case of back-door-listing, this fad is reinforced by the possibility of window dressing.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2002.11a
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• pp.139-143
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• 2002

IDS, Firewall 등의 보안도구들은 보편화되어 있는 보안 솔루션이다. 시스템의 보안을 책임지는 이러한 도구들이 보안상 문제점(즉, 우회 공격 가능성)을 가지고 있다는 것은 보안에 있어 근본적인 부분이 취약성을 내포하고 있는 것과 같다. 그러므로 시스템 및 네트워크에 대한 새로운 보안 기법을 연구하기에 앞서 현재의 보안 솔루션들이 가지고 있는 우회공격과 같은 위험성을 해결하는 것 필수적이다. 따라서 본 논문에서는 일반적으로 사용되는 보안 솔루션들에 대한 우회 공격 기술 분석 및 대응 방안에 관한 연구를 수행한다.

• Review of KIISC
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• v.13 no.2
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• pp.92-105
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• 2003

IDS, Firewall 등의 보안도구들은 보편화되어 있는 보안 솔루션이다. 시스템의 보안을 책임지는 이러한 도구들이 보안상 문제점(즉, 우회공격 가능성)을 가지고 있다는 것은 보안에 있어 근본적인 부분이 취약성을 내포하고 있는 것과 같다. 그러므로 시스템 및 네트워크에 대한 새로운 보안기법을 연구하기에 앞서 현재의 보안 솔루션들이 가지고 있는 우회공격과 같은 위험성을 해결하는 것 필수적이다. 따라서 본 논문에서는 일반적으로 사용되는 보안 솔루션들에 대한 우회공격 기술 분석 및 대응 방안에 관한 연구를 수행한다.

• Journal of the Korea Society of Computer and Information
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• v.14 no.12
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• pp.181-190
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• 2009

DBMS access that used high speed internet web service through WAS is increasing. Need application of DB security technology for 3-Tier about DBMS by unspecified majority and access about roundabout way connection and competence control. If do roundabout way connection to DBMS through WAS, DBMS server stores WAS's information that is user who do not store roundabout way connection user's IP information, and connects to verge system. To DBMS in this investigation roundabout way connection through WAS do curie information that know chasing station security thanks recording and Forensic data study. Store session about user and query information that do login through web constructing MetaDB in communication route, and to DBMS server log storing done query information time stamp query because do comparison mapping actuality user discriminate. Apply making Rule after Pattern analysis receiving log by elevation method of security authoritativeness, and develop Module and keep in the data storing place through collection and compression of information. Kept information can minimize false positives of station chase through control of analysis and policy base administration module that utilize intelligence style DBMS security client.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.5
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• pp.818-828
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• 2018

Nowadays, various security systems are developed and used for protecting information on the network. Although security solutions can prevent some of the security risks, they provide high performance only if used appropriately in accordance with their purposes and functionality. Security solutions commonly used in information protection systems include firewalls, IDS, and IPS. However, despite various information protection systems are introduced, there are always techniques that can threaten the security systems through bypassing them. The purpose of this paper is to develop effective training techniques for responding to the bypass attack techniques in the information security systems and to develop effective techniques that can be applied to the training. In order to implement the test bed we have used GNS3 network simulator, and deployed it on top of virtual operating system using VirtualBox. The proposed correspondence training scenario against bypassing information protection system attacks could be very effectively used to counteract the real attacks.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.3
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• pp.41-50
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• 2010

This paper presents an investigation result that is made to determine dominant influencing factors and their specific impacts on motorist detour makings for VMS placements on freeway. This was necessary to provide engineers with a tool for evaluating VMS cost-effectiveness and its feasibility. This research found that additional travel time delay is the most influential variable in determining motorist detour makings. Also, more than 70% freeway motorists recognize the adjacent national roads as their detour routes, and both AADT and the distance to the entering point of the detour path are found to be dominating factors. Motorist detour ratio model by VMS placement on freeway is developed based on the Stated Preference. In model validation, actual detour making behaviors observed by the Revealed Preference values verify the detour ratio on the Stated Preference. These research findings should be useful for cost-effective placements of VMS on freeway, and it is recommended that the results be tested by practicing engineers in the ITS sector.