• Journal of the Korea Society for Simulation
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• v.21 no.4
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• pp.91-102
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• 2012

Network port scan attack is the method for finding ports opening in a local network. Most existing IDSs(intrusion detection system) record the number of packets sent to a system per unit time. If port scan count from a source IP address is higher than certain threshold, it is regarded as a port scan attack. The degree of risk about source IP address performing network port scan attack depends on attack count recorded by IDS. However, the measurement of risk based on the attack count may reduce port scan detection rates due to the increased false negative for slow port scan. This paper proposes a method of summarizing 4 types of information to differentiate network port scan attack more precisely and comprehensively. To integrate the riskiness, we present a risk index that quantifies the risk of port scan attack by using PCA. The proposed detection method using risk index shows superior performance than Snort for the detection of network port scan.

• Journal of Digital Contents Society
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• v.18 no.5
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• pp.989-994
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• 2017

In this paper, we propose a pothole detection system using 2D LiDAR and a pothole detection algorithm. Conventional pothole detection methods can be divided into vibration-based method, 3D reconstruction method, and vision-based method. Proposed pothole detection system uses two inexpensive 2D LiDARs and improves pothole detection performance. Pothole detection algorithm is divided into preprocessing for noise reduction, clustering and line extraction for visualization, and gradient function for pothole decision. By using gradient of distance data function, we check the existence of a pothole and measure the depth and width of the pothole. The pothole detection system is developed using two LiDARs, and the 3D pothole detection performance is shown by detecting a pothole with moving LiDAR system.

• Journal of the Korea Society of Computer and Information
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• v.13 no.5
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• pp.37-44
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• 2008

In recent years, e-portfolios and webfolios have been highly vaunted as the next great innovation in education. Hundreds of academic institutions are variously studying, using, or innovating e-portfolio systems. Despite the presumed goodness of e-portfolios, some problems remain. In this paper we review the existing e-portfolio management systems, and propose and implement a novel system to overcome the limits of the existing e-portfolio management systems. The propose e-portfolio management system has a structure of competition with others. All of the student's activities are accomplished and preserved within the same personal web space like a blog with mutual engagements and recommendations.

• Journal of Digital Convergence
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• v.6 no.3
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• pp.85-91
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• 2008

본 연구는 프로젝트 선정 및 포트폴리오 관리에 관한 고찰이다. 첫 번째 부분은 프로젝트 선정에 관한 세 가지 방법 (AHP, 경제학적 방법, Microsoft's Enterprise 프로젝트 관리 방법)의 장 단점에 대한 간단한 견해를 제시하였다. 두 번째 부분은 프로젝트 포트폴리오 관리에 관한 기법 등을 소개하였고, 6개의 질문을 통해 프로젝트 포트폴리오 관리 시스템에 대해 어떻게 조직화하고 활용할 것인가를 고찰하였다.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.520-525
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• 2009

본 연구은 해석적인 접근을 통하여 소형엔진 흡기포트 설계인자의 변화에 따른 유량계수를 고찰하였다. 기존모델을 Valve Lift별 유량계수들을 해석하였으며 그 중 유량계수가 일정해지는 구간의 Valve Lift를 기준으로 설계인자 변화에 따른 성능해석을 수행하였다. 결론적으로, 흡기포트 유량계수를 결정하는 중요한 인자는 포트각도와 유선형상임을 확인하였고 이들 값의 최적화를 수행하였다. 흡기포트의 유량계수를 결정하는 설계인자로는 포트각도, 흡기포트의 유선형상, Port Height_Guide, Flange 면적이 있다. 포트각도의 상승이 유량계수를 상승시키지만 그에 따른 굴절 및 Dead Volume의 발생으로 오히려 유량계수 측면에서는 불리한 조건이 되기도 한다. 급격한 형상변화 부분에서 박리현상이 발생되는데 이에 유동을 위한 곡률을 적용하여 급격한 형상변화를 줄여 박리형상을 감쇄시키고, Dead Volume 삭제하여 원활한 유동특성을 만들 수 있다.

• Proceedings of the Technology Innovation Conference
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• 2005.02a
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• pp.3-21
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• 2005

기업은 경쟁력 강화를 위해 지속적으로 프로젝트에 자원을 투자해야 하지만 기업의 물리적, 재정적 제약으로 인해 제안된 모든 프로젝트에 자원을 투자할 수가 없다. 따라서 기업의 장기적인 생존을 위해서는 프로젝트 포트폴리오의 최적선정이 필수적 과제이다. 이러한 중요성에 대한 인식으로 현재까지 많은 프로젝트포트폴리오 선정 방법들이 개발되었으나, 프로젝트 포트폴리오 선정을 지원하는 통합화된 프레임워크의 설계에 대한 연구는 미약한 실정이다. 본 연구는 최적 프로젝트 포트폴리오를 선정하기 위한 프레임워크를 설계하는 것으로서 프로젝트 포트폴리오 선정을 위한 설계방법론, 기존 프로젝트 포트폴리오 선정 프레임워크에 대한 분석 및 새로운 프로젝트 포트폴리오 선정 프레임워크의 설계에 대해 서술한다.

• The Journal of the Korea Contents Association
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• v.8 no.5
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• pp.260-267
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• 2008

The portfolio provides a method which can properly evaluate the student's long term period of learning and growth, and this allows students to have practical learning through self-reflection. However, following the realities of portfolio's operation, the portfolio is being operated formally just once only for the evaluation due to the difficulty of long custody and its time-consuming process. In this paper, after grasping the overall process of learning and the result of growth, we design the 'e-portfolio' which combines both learning and evaluation in order to minimize the physical constraint factors along with operating portfolio. After operating our newly designed 'e-portfolio' based on blog in order to verify it's effect, we found the meaningful changes in student's academic achievement and the positive possibility of its application to teachers. Therefore, with the operation of our suggested 'e-portfolio', we are expecting progressed and integrated portfolio education which combines the function of the learning and the evaluation.

• KIISE Transactions on Computing Practices
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• v.22 no.1
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• pp.8-19
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• 2016

Potholes are caused by the presence of water in the underlying soil structure, which weakens the road pavement by expansion and contraction of water at freezing and thawing temperatures. Recently, automatic pothole detection systems have been studied, such as vibration-based methods and laser scanning methods. However, the vibration-based methods have low detection accuracy and limited detection area. Moreover, the costs for laser scanning-based methods are significantly high. Thus, in this paper, we propose a new pothole detection system using a commercial black-box camera. Normally, the computing power of a commercial black-box camera is limited. Thus, the pothole detection algorithm should be designed to work with the embedded computing environment of a black-box camera. The designed pothole detection algorithm has been tested by implementing in a black-box camera. The experimental results are analyzed with specific evaluation metrics, such as sensitivity and precision. Our studies confirm that the proposed pothole detection system can be utilized to gather pothole information in real-time.

• Journal of The Geomorphological Association of Korea
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• v.19 no.2
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• pp.113-122
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• 2012

The geomorphic properties of potholes at Naerin River, Inje-gun are analyzed to discover the geosites of DMZ geopark in Gangwon-do. The furrow-type potholes along the river flow are mainly found in the P1 and P2 sites. The P3 site can be divided in to the zones where the furrow-type potholes densely distribute and various types of potholes are scattered, while the various types of small potholes are scattered in the P4 site. After measuring the 44 potholes, the potholes with a U-shaped cross-section, similar directivity with river flow and deposited gravels with in them show large values in length, width, depth and slope. Because the P1 and P2 sites are characteristic in the scales and forms of potholes and show beautiful scapes, it can be suggested that they are suitable for the geosite developments.

• International Area Studies Review
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• v.20 no.4
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• pp.121-145
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• 2016

The purpose of this study is to identify the strategy of alliance portfolio and to compare the firm's characteristics and internal capabilities of each strategy for the successful utilization of alliance. We conducted a cluster analysis and ANOVA on 477 samples, which have alliance experience among the manufacturers responding to the Business Survey by Statistical Office in both 2012 and 2013. As a result of the analysis, it was found that firms have alliance portfolio based on strategy such as exploration, exploitation, and ambidextrity. There are statistically significant differences in the number of patents, technology capability, marketing capability, and global capability among the alliance portfolio strategy type.