• 터널과지하공간
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• 제18권3호
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• pp.226-238
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• 2008

숏크리트의 지보성능을 보완하기 위해 사용되는 강지보재는 매우 효과적인 것으로 평가되지만 강지보재 종류별 성능이 파악되지 못하여 설계에 제대로 반영하지는 못하고 있다. 본 연구에서는 여러 가지 강지보재에 의해 보강된 숏크리트의 특성을 휨인성 시험을 통하여 파악하고, 그 결과를 수치해석에 반영하고자 하였다. 시험결과 철근보강 숏크리트는 H 형강이나 격자지보에 비해 지보능력이 다소 못 미치는 것으로 나타났는데, 이는 시험체가 휨인장 파괴를 유도하기에는 다소 짧아서 전단파괴가 발생하였기 때문인 것으로 나타났다. 수치해석을 이용한 안정성 해석 시 숏크리트와 강지보재를 별도로, 그리고 이들 복합체에 대한 등가물성을 구하여 각각 해석한 바 두 결과가 잘 일치하여 등가물성을 이용한 복합체 해석으로도 간편하게 강지보재의 효과를 모사할 수 있었다.

• Korean Journal of Geomatics
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• 제1권1호
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• pp.1-5
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• 2001

This paper presents an investigation into the operational comparison of SPOT triangulation to build GCP library by analytical plotter and DPW (digital photogrammetric workstation). GCP database derived from current SPOT images can be used to other image sensors of satellite, if any reasons, such as lack of topographic maps or GCPs. But, general formulation of a photogrammetric process for GCP measurement has to take care of the scene interpretation problem. There are two classical methods depending on whether an analytical plotter or DPW is being used. Regardless of the method used, the measurement of GCPs is the weakest point in the automation of photogrammetric orientation procedures. To make an operational comparison, five models of SPOT panchromatic images (level 1A) and negative films (level 1AP) were used. Ten images and film products were used for the five GRS areas. Photogrammetric measurements were carried out in a manual mode on P2 analytical plotter and LH Systems DPW770. We presented an approach for exterior orientation of SPOT images, which was based on the use of approximately eighty national geodetic control points as GCPs which located on the summit of the mountain. Using sixteen well-spaced geodetic control points per model, all segments consistently showed RMS error just below the pixel at the check points in analytical instrument. In the case of DPW, half of the ground controls could not found or distinguished exactly when we displayed the image on the computer monitor. Experiment results showed that the RMS errors with DPW test was fluctuated case by case. And the magnitudes of the errors were reached more than three pixels due to the lack of image interpretation capability. It showed that the geodetic control points is not suitable as the ground control points in DPW for modeling the SPOT image.

• Structural Engineering and Mechanics
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• 제13권5호
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• pp.557-568
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• 2002

For the evaluation of the capability of a tubular member of an offshore structure to absorb the collision energy, a simple method can be employed for the collision analysis without performing the detailed analysis. The most common simple method is the rigid-plastic method. However, in this method any characteristics for horizontal movement and rotation at the ends of the corresponding tubular member are not included. In a real structural system of an offshore structure, tubular members sustain a certain degree of elastic support from the adjacent structure. End fixity has influences in the behaviors of a tubular member. Three-dimensional FEM analysis can include the effect of end fixity fully, however in viewpoints of the inherent computational complexities of the 3-D approach, this is not the recommendable analysis at the initial design stage. In this paper, influence of end fixity on the behaviors of a tubular member is investigated, through a new approach and other approaches. A new analysis approach that includes the flexibility of the boundary points of the member is developed here. The flexibility at the ends of a tubular element is extracted using the rational reduction of the modeling characteristics. The property reduction is based on the static condensation of the related global stiffness matrix of a model to end nodal points of the tubular element. The load-displacement relation at the collision point of the tubular member with and without the end flexibility is obtained and compared. The new method lies between the rigid-plastic method and the 3-demensional analysis. It is self-evident that the rigid-plastic method gives high strengthening membrane effect of the member during global deformation, resulting in a steeper slope than the present method. On the while, full 3-D analysis gives less strengthening membrane effect on the member, resulting in a slow going load-displacement curve. Comparison of the load-displacement curves by the new approach with those by conventional methods gives the figures of the influence of end fixity on post-yielding behaviors of the relevant tubular member. One of the main contributions of this investigation is the development of an analytical rational procedure to figure out the post-yielding behaviors of a tubular member in offshore structures.

• Bulletin of the Korean Chemical Society
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• 제23권6호
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• pp.837-845
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• 2002

Based on ab initio calculations at the MP2(FULL)/6-31+G**//RHF/6-31G** level, we compare the energetic and mechanistic features of a model reaction for catalytic action of Δ?-3-ketosteroid isomerase (KSL,E.C.5.3,3.1) with those of a corresponding nonenzymatic reaction in aqueous solution. The results show that the two catalytic acid residues,Tyr14 and Asp99, can lower the free energy of activation by 8.6kcal/mol, which is in good agreement with the experimentally predicted~9 kcal/mol,contribution of electrophilic catalyses to the whole enzymatic rate enhancement. The dienolate intermediate formed by proton transfer from the substrate carbon acid to the catalytic base residue (Asp38) ins predicted to be stabilized by 12.0 kcal/mol in the enzymatic reaction, making its formation thermodynamically favorable. It has been argued that enzymes catalyzing the reactions of carbon acids should resolve the thermodynamic problem of stabilizing the enolate intermediate as well as the kinetic porblem of lowering the free energy of activation for porton abstraction. We find that KSI can successfully overcome the thermodynamic difficulty ingerent in the nonenzymatic reaction through the electrophilic catalyses of the two acid residues. Owing to the stabilization of dienolate intermediate, the reketonization step could influence the overall reaction rate more significantly in the KSI- catalyzed reaction than in the nonenzymatic reaction, further supporting the previous experimental findings. However, the electrophilic catalyses alone cannot account for the whole catalygic capability (12-13 kcal/mol), confiming the earlier experimental implications for the invement of additional catalytic components. The present computational study indicates clearly how catalytic residues of KSI resolve the fundamental problems associated with the entropic penalty for forming the rate-limiting transition state and its destabilization in the bulk solvation environment.

• 정보보호학회논문지
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• 제27권3호
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• pp.563-577
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• 2017

인터넷과 컴퓨터의 발달로 인해 신종 변종 악성코드가 하루에 약 1백만 개씩 출현하고 있다. 더욱이 기업을 대상으로 하는 표적공격의 경우 알려지지 않은 악성코드를 통해 공격이 진행되므로 전통적인 시그니처에 의한 탐지 방법은 대응에 대한 효율성이 낮게 되어 많은 기업들은 새로운 샌드박스와 같은 동적 분석 시스템을 도입하였다. 그러나 실행 파일뿐만 아니라 워드문서 또는 PDF 형태의 악성코드도 지속적으로 증가하고 있으며 새로운 악성코드 또한 동적 분석 시스템을 우회하는 기술을 포함하고 있어 효율적인 운영을 위해 많은 자원이 필요하고 새로운 기술이 필요하게 되었다. 본 연구에서는 효율적인 동적 분석 시스템을 위해 사전 필터링 기술을 사용하여 효율성을 향상시키기 위한 사전 필터링 기술 선정 요소를 도출하고 기술 도입 시 합리적인 선택을 할 수 있도록 AHP(Analytics Hierarchy Process)를 사용하여 의사 결정 모델을 제시하고, 도입 시 활용할 수 있도록 공식을 제시하고 검증하였다.

• 한국산학기술학회논문지
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• 제16권6호
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• pp.4137-4146
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• 2015

시스템의 규모와 요구기능은 점점 대형화되고 복잡해지고 있다. 이러한 시스템 개발 프로젝트의 성공적인 수행을 위해서는 프로세스에 따른 체계적인 시스템공학(SE)과 프로젝트관리(PM) 활동이 요구되고 있다. 시스템 개발 조직에서는 SE&PM 프로세스 개선 및 능력평가 모델인 CMMI를 채택하여 SE&PM 능력 확보에 노력하고 있으며, 이를 위해 조직의 비즈니스 특성에 맞는 조직 표준 프로세스를 구축하여 적용하고 있다. 하지만 시스템 개발조직 현장에서는 CMMI 프로세스영역 간 상호연관성에 대한 충분한 이해부족으로 조직 프로세스 구축에 어려움이 따르고 있다. 또한 SE와 PM활동은 시스템 개발에 있어서 상호 밀접하게 연관되어 있기 때문에 SE와 PM 프로세스는 상호 통합 및 연계성이 확보되어야만 효과적이고 효율적인 프로젝트 수행이 될 것이다. 본 논문에서는 시스템 개발 조직에서 CMMI 기반 조직 프로세스 구축에 참조되고 활용될 수 있는 조직의 SE&PM 통합 프로세스 아키텍처를 제시한다.

• Journal of Information Processing Systems
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• 제14권3호
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• pp.751-770
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• 2018

Web applications are indispensable in the software industry and continuously evolve either meeting a newer criteria and/or including new functionalities. However, despite assuring quality via testing, what hinders a straightforward development is the presence of defects. Several factors contribute to defects and are often minimized at high expense in terms of man-hours. Thus, detection of fault proneness in early phases of software development is important. Therefore, a fault prediction model for identifying fault-prone classes in a web application is highly desired. In this work, we compare 14 machine learning techniques to analyse the relationship between object oriented metrics and fault prediction in web applications. The study is carried out using various releases of Apache Click and Apache Rave datasets. En-route to the predictive analysis, the input basis set for each release is first optimized using filter based correlation feature selection (CFS) method. It is found that the LCOM3, WMC, NPM and DAM metrics are the most significant predictors. The statistical analysis of these metrics also finds good conformity with the CFS evaluation and affirms the role of these metrics in the defect prediction of web applications. The overall predictive ability of different fault prediction models is first ranked using Friedman technique and then statistically compared using Nemenyi post-hoc analysis. The results not only upholds the predictive capability of machine learning models for faulty classes using web applications, but also finds that ensemble algorithms are most appropriate for defect prediction in Apache datasets. Further, we also derive a consensus between the metrics selected by the CFS technique and the statistical analysis of the datasets.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.56-60
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• 2008

Increasing urban sprawl and climate changes have been causing unexpected high-intensity rainfall events. Thus there are needs to enhance conventional disaster management system for comprehensive actions to secure safety. Therefore long-term and comprehensive flood management plans need to be well established. Recently torrential snowfall are occurring frequently, causing have snow traffic jams on the road. To secure safety and on-time operation of the Bi-modal tram system, well-structured disaster management system capable of analyzing the urban flash flooding and snow pack melt/freezing due to unexpected rainfall event and snowfall are needed. To secure safety of the Bi-modal tram system due to torrential snowfall, the snow melt simulation capability was investigated. The snow accumulation and snow melt were measured to validate the SWMM snow melt component. It showed that there was a good agreement between measured snow melt data and the simulated ones. Therefore, the Bi-modal tram disaster management system will be able to predict snow melt reasonably well to secure safety of the Bi-modal tram system during the winter. The Bi-modal tram disaster management system can be used to identify top priority area for snow removal within the tram route in case of torrential snowfall to secure on-time operation of the tram. Also it can be used for detour route in the tram networks based on the disaster management system predicted data.

• 한국콘텐츠학회논문지
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• 제18권11호
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• pp.317-326
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• 2018

본 연구는 제한된 합리성 하에서 다문화정책의 상대적 중요도와 우선순위를 도출하기 위해 AHP모델을 작성하여 전문가 평가를 실시하였다. 연구결과는 다음과 같다. 첫째, 측정영역에서는 안정된 사회정착지원정책(1순위), 다문화 가족 2세들의 사회적 역량개발 정책(2순위), 사회 경제활동 지원정책(3순위), 협력적 거버넌스(4순위)의 순으로 정책 우선순위가 평가되었다. 둘째, 측정요소의 우선순위이다. 안정된 사회정착 지원정책에서는 사회정착 서비스 대상 확대정책, 다문화 가족 2세들의 사회적 역량개발 정책에서는 사회적 진출지원 정책이 가장 중요하게 평가되었다. 사회 경제활동지원 정책에서는 적극적 경제활동 지원정책, 협력적 거버넌스 정책 추진에서는 정책실천주체들의 협력시스템 구축이 가장 중요한 정책 우선순위로 평가되었다. 이런 연구결과는 다문화정책을 현실적 차원에서 설명하는데 기여할 것으로 판단된다.

• 한국컴퓨터정보학회논문지
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• 제28권1호
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• pp.151-159
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• 2023

디지털 시대에 혁신은 정보기술발전의 핵심이다. 본문은 혁신 시스템 내 지역혁신능력의 차이를 새로운 관점에서 분석하고 있다. 본 연구는 커플링조정모델을 이용하여 중국의 31개 성, 시, 자치구의 혁신시스템(혁신투입, 혁신산출, 혁신환경)에 대해 커플링 정도를 비교 분석하고 있다. 분석 결과는 두 가지로 요약할 수 있다. 첫째, 중국의 전반적인 커플링 조정 수준은 낮다. 그리고 양호한 커플링과 높은 수준의 커플링 단계에 있는 지역의 수는 많지 않다. 둘째, 커플링의 전반적인 추세는 상승하고 있으나, 상대적으로 양호한 커플링 단계에 있는 지역은 대부분이 지역경제발전 수준이 높은 동부 연해안 지역에 분포되어 있다. 본문의 연구 결과는 혁신 능력 평가에 대한 새로운 관점을 제공할 수 있으며, ICT 산업의 발전을 촉진하는 데 혁신이 중요한 영향을 미칠 수 있음을 강조하고 있다.