• Journal of KIISE:Computer Systems and Theory
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• v.35 no.9_10
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• pp.421-428
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• 2008

A. Ghafoor proposed Even networks as a class of fault-tolerant multiprocessor networks in [1] and analyzed so many useful properties include node disjoint paths. By introducing node disjoint paths in [1], fault diameter of Even networks is d+2(d=odd) and d+3(d=even). But the lengths of node disjoint paths proved in [1] are not the shortest. In this paper, we show that Even network Ed is node symmetric. We also propose the shortest lengths of node disjoint paths using cyclic permutation, and fault diameter of Even networks is d+1.

• Journal of Korean Ophthalmic Optics Society
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• v.4 no.1
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• pp.27-35
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• 1999

The corneal power and eye refraction error were studed in 472 unaccommodated right eyes of Korean adult human aged above 20 years. The mean corneal refractive power is 44.08D (female : 44.28D, male : 43.76D). It is 1.1D higher than that of the medel eye by Gullstrand (about 43.0D). The mean corneal power of myopia(44.11D) is similar that of emmetropia(43.97D) and hyperopia(44.24D), but mean corneal power of myopia between the ages of 20 and 29 is 1.42D higher than that of emmetropia. The corneal powers as a function of ages are enlarged with increasing rate of 0.2D~0.3D/10years.

• Journal of the Korean Society for information Management
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• v.22 no.3 s.57
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• pp.103-127
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• 2005

The purpose of the study is to implement the management model of the institutional repositories for the efficient distribution infrastructure of national knowledge focusing on the dCollection system which is operated by KERIS (service provider). In order to build the management model, the two steps were utilized. The first step is to investigate the checklists of repositories that are important factors for the successful repository implementation through literature review. On the other hand, the second one is to survey the current status of the sixteen domestic and foreign institutional repositories through interviews, surveys and email as well as the repository home pages and literature reviews. Through the two steps, the management model including six components such as content and librarian role was proposed. The proposed management model will be utilized to supply guides both to the universities which plan to build their institutional repositories and to the universities which try to promote the activities of their repositories.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.395-395
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• 2020

연안 지역의 침수 모의에 관한 국내 연구들은 간단한 월파량 공식 및 조위와 강우만을 결합하여 모의하였거나, 강우 없이 조위와 월파만을 고려하여 모의한 경우가 대부분이었다. 그렇지만 연안 지역의 침수는 강우와 (조위 포함) 월파가 시간에 따라 변하면서 발생하므로, 두 외력조건을 고려하는 침수 모의가 필요하다. 이에 본 연구에서는 연안지역의 침수 분석 시 강우-유출 분석과 2차원 지표면 침수 해석이 가능한 XP-SWMM을 이용하여 강우와 월파의 시간 변화를 고려한 침수 모의 방법론을 제시하고자 한다. 우선 FLOW-3D 모형을 사용하여 연안 지역의 흐름 분석과 월파량 시계열을 산정하였고, XP-SWMM에 산정된 월파량 시계열을 입력하기 위해 해안가 지역에 절점을 생성하였다. 절점의 위치는 FLOW-3D 모형에서 월파량 시계열을 산정한 격자의 중심 위치이다. 월파량 시계열 산정 시 FLOW-3D 모형의 격자를 XP-SWMM에서 모두 고려하기에는 많은 시간이 소요되므로 3개의 격자를 묶어 하나의 절점으로 구현하였고, 3개의 격자에서 산정된 월파량 시계열의 합을 해당 절점에 반영하여 XP-SWMM으로 침수 모의를 진행하였다. 제시된 방법의 적절성을 검토하기 위해 강우와 월파가 동시에 발생한 태풍 차바 내습 시 부산에 위치한 마린시티에 적용하였다. 분석 결과, 한국국토정보공사에서 제공하는 침수흔적도와 모의 결과가 유사함을 확인하였다. 본 연구는 연안 지역의 침수 해석 시 XP-SWMM으로 강우와 함께 월파를 고려한 침수 모의 방법을 제시한 연구 사례로서 의의가 있다. 이는 XP-SWMM의 범용성과 호환성을 높이는 방법론이며, 실제 침수 현상과 가깝게 재현할 수 있다고 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.302-307
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• 2017

본 연구에서 퇴사량조사 실적 및 유량-유사량 관측 자료, 상 하류 수위-유량 자료를 보유하고 있는 B 저수지를 대상으로 3차원 수치모형을 이용하여 저수지 퇴사분포를 분석해 보았다. 또한 수치모형의 검증을 위하여 저수지내 6개 지점에 대한 시추 샘플링을 통해 퇴적토의 깊이를 측정하였다. 퇴적토 샘플링시 시료의 교란을 방지하기 위하여 동일지점에서 2회 샘플링 작업을 수행하였다. 샘플링 시료는 원지반과 퇴적지반의 구분을 위하여 시료분석 이전에 각 단면별 깊이를 측정하였으며, 시료는 각 단면별로 물리적 특성시험을 통해 압밀도를 측정하여 퇴적토의 깊이를 산정하고 수치모형시 검증 자료로 사용하였다. 본 연구에서는 3차원 수리해석과 함께 유사의 이송, 침식, 퇴적현상을 연동하여 모의 가능한 Delft3D 모형을 이용하여 B 저수지에 대한 유사 이송모의를 수행하였다. 모의 결과 저수지의 하폭이 넓어지는 지형 및 만곡부 인근에서 퇴적이 진행되는 결과를 보였으며, 퇴적토 시료와 비교한 결과 퇴적토 깊이는 일부 차이가 있었으나, 퇴적분포 양상은 유사한 결과를 보였다.

• Journal of the Korean GEO-environmental Society
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• v.21 no.9
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• pp.15-24
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• 2020

In this study, the stress concentration ratio for the improved material of the low slump mortar grouting was evaluated through the composite ground method, the ground arching theory, the plastic angle method, the 2D and 3D numerical analysis and the 3D model experiment. The stress concentration ratio calculated by the composite ground method was 89.3, 3.75~59.0 when the three-dimensional ground arching theory was applied, and 82.8 for the three-dimensional plastic angle method. As a result of the 2D numerical analysis, the stress concentration ratio was 63.0~77.0, which was found to increase as the improvement ratio increased. The results of 3D numerical analysis were predicted to be 50.0~56.0 smaller than the results of 2D analysis. In the case of a special model experiment using a large triaxial compression cell, the stress concentration ratio for each load step was 53.0~60.0, and the stress concentration ratio evaluated by the experiment was measured within 2D and 3D numerical analysis predictions. In this study, a predictive equation for the stress concentration ratio according to the improvement ratio is proposed based on the analysis and experimental values for the improved ratio of the low slump mortar grouting.

• Journal of Technology Innovation
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• v.31 no.3
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• pp.171-199
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• 2023

The purpose of this study was to develop an evaluation tool for selecting new projects for R&D project planning level of K Research Institute. For this purpose, items and questions for R&D project selection evaluation were developed based on the CIPP model and previous studies on selection evaluation and evaluation indicators for research project evaluation, and then two Delphi surveys were conducted. The developed evaluation tool was surveyed by 13 experts to verify contents validity ratio, convergence and consensus. The finally selected evaluation tool for R&D project planning consisted of 21 questions in 8 items, including 5 questions for context evaluation, 2 questions for input evaluation, 8 questions for process evaluation, and 6 questions for product evaluation. The evaluation tool developed will contribute to the solution of problems in the bottom-up planning process and to the improvement of the planning competence of the researchers. It will also contribute to improve the consistency and efficiency of evaluation during the selection process.

• Journal of KIISE:Software and Applications
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• v.33 no.3
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• pp.335-343
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• 2006

This paper proposes a novel technique of marker-based 2D-3D registration to combine 3D information obtained from preoperative CT images into 2D image obtained from intraoperative x-ray fluoroscopy image. Our method is divided into preoperative and intraoperative procedures. In preoperative procedure, we generate CT-derived DRRs using graphics hardware and detect markers automatically. In intraoperative procedure, we propose a hierarchical two- step registration to reduce a degree of freedom from 6-DOP to 2-DOF which is composed of in-plane registration using principal axis method and out-plane registration using minimal error searching method in spherical coordinate. For experimentation, we use cardiac phantom datasets with confirmation markers and evaluate our method in the aspects of visual inspection, accuracy and processing time. As experimental results, our method keeps accuracy and aligns very fast by reducing real-time computations.

• Journal of the Korean GEO-environmental Society
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• v.17 no.7
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• pp.5-13
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• 2016

This research is focused on the seepage behavior of embankment which had the weak zone with big permeability. The distributed TDR (Time Domain Reflectometer) and point sensors such as settlement gauge, pore water pressuremeter, vertical total stressmeter, and FDR (Frequency Domain Reflectometer) sensor were used to measure the seepage characteristics and embankment behavior. Also, the measured data were compared to the data of 2-D and 3-D numerical analysis. The dimension of model embankment was 7 m length, 5 m width and 1.5 m height, which is composed of fine-grained sands and the water level of embankment was 1.3 m height. The seepage behavior of measuring and numerical analysis were very similar, it means that the proper sensing system can monitor the real-time safety of embankment. The result by 2-D and 3-D numerical analysis showed similar saturation processing, however in case of weak zone, the phreatic lines of 2-D showed faster movement than that of 3-D analysis, and finally they converged.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.3
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• pp.609-623
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• 2018

If the ground is excavated in a depth which is deeper than the adjacent existing tunnel, the behavior of the braced wall is known to be greatly affected by the presence of the tunnel. By the way it is expected to be also affected by the structure on the ground surface, There are not many examples of studies which are conducted on this subject. As a result, largel scale model tests and analysis were conducted, to measure the behavior of the tunnel under the building whose location on the ground surface was varied during the adjacent ground excavation. For this purpose, the location of a building load was varied in 0 m, 1D, 2D on ground surface. In this paper, the behaviors of braced wall and adjacent tunnel was studied. Model tests in 1 : 10 scale were performed in real construction sequences. The size of test pit was $2.0m(width){\times}6.0m(height){\times}4.0m(length)$ in dimension. As a result, it was found that the stability of the existing tunnel under the influence of the building load on the ground surface adjacent to the braced wall.