• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.2
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• pp.62-72
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• 2019

Due to the difficulties in forecasting the intensity and the source location of tsunami the countermeasures prepared based on the deterministic approach fail to work properly. Thus, there is an increasing demand of the tsunami hazard analyses that consider the uncertainties of tsunami behavior in probabilistic approach. In this paper a fundamental study is conducted to perform the probabilistic tsunami hazard analysis (PTHA) for the tsunamis that caused the disaster to the east coast of Korea. A logic tree approach is employed to consider the uncertainties of the initial free surface displacement and the tsunami height distribution along the coast. The branches of the logic tree are constructed by reflecting characteristics of tsunamis that have attacked the east coast of Korea. The computational time is nonlinearly increasing if the number of branches increases in the process of extracting the fractile curves. Thus, an improved method valid even for the case of a huge number of branches is proposed to save the computational time. The performance of the discrete weight distribution method proposed first in this study is compared with those of the conventional sorting method and the Monte Carlo method. The present method is comparable to the conventional methods in its accuracy, and is efficient in the sense of computational time when compared with the conventional sorting method. The Monte Carlo method, however, is more efficient than the other two methods if the number of branches and the number of fault segments increase significantly.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1993.04a
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• pp.424-436
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• 1993

패널내 추계적 성분들의 공분산 관계(variance-covariance structure)를 이용한 ML 추정법을 항상소득가설(PIH)의 검증에 적용하였다. Hall & Mishkin의 모형을 기초로 분기별 이분산성(heteroscedasticity)을 고려한 모형의 추정결과 전체 소비변동 중 약 11%가 과도민감성에 의한 것으로 나타났다.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.803-804
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• 2006

This paper presents a multiple branch predictor with perceptrons. We describe our design and evaluate it with the SPEC 2000 benchmarks. Our predictor achieves increased accuracy than the previous multiple branch predictors.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.2
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• pp.129-138
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• 2016

This paper presents a natural corners-based SLAM (Simultaneous Localization and Mapping) with a robust data association algorithm in a real unknown environment. Corners are extracted from raw laser sensor data, which are chosen as landmarks for correcting the pose of mobile robot and building the map. In the proposed data association method, the extracted corners in every step are separated into several groups with small numbers of corners. In each group, local best matching vector between new corners and stored ones is found by joint compatibility, while nearest feature for every new corner is checked by individual compatibility. All these groups with local best matching vector and nearest feature candidate of each new corner are combined by partial compatibility with linear matching time. Finally, SLAM experiment results in an indoor environment based on the extracted corners show good robustness and low computation complexity of the proposed algorithms in comparison with existing methods.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.4
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• pp.171-176
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• 2021

This paper deals with bid evaluation problem that chooses the vendors and quantity with minimum purchasing cost for bid information of setup cost and unit price. For this problem, the branch-and-bound(BB) and branch-and-cut(BC) methods are well-known. But these methods can be fail to obtain the optimal solution. This paper gets the initial feasible solution with procuring quantity assignment principle in accordance with the unit price or setup cost rank-first. Then procuring quantity moving optimization(vendor change) is execute take account of unit price or setup cost rank. As a result of experimentation, the propose algorithm is significantly lower compared to BB and BC.

• JOURNAL OF ELECTRICAL WORLD
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• s.308
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• pp.76-79
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• 2002

이제 기업별로 분기이익을 발표하는 Earning Season이 돌아왔다. 분기보고에 나타난 실적을 기초자료로 하여 기업들은 내부적으로 자사의 성과를 평가하고 주식시장에서는 투자자들이 기업을 평가하는 기본 자료로 활용하여 온 것이 주지의 사실이라고 할 수 있다. 그러나 엔론사태를 시발로하여 현재까지 꼬리를 물고있는 미국 기업에 대한 회계조작 사건은 기업회계에 대한 신뢰성의 저하를 초래했다. 세계에서 가장 투명한 경영을 한다는 미국의 대기업들이 이러한 사건에 연류되면서 상대적으로 투명성이 의심되는 국가의 기업들은 회계조작과 관련이 없더라도 이러한 악재를 피해 가기는 힘든 것이 현실이다. 회계의 투명성에 대한 신뢰도는 단순한 문제라고 할 수만은 없다. 왜냐하면 회계의 신뢰성에 대한 문제는 기업의 펀드멘탈에 관련된 문제이기 때문이다. 이러한 연유로 자본주의 경제와 불가분의 관계인 회계에 대한 비판과 개혁론이 대두되고 있어 대안적인 방안들이 관심을 끌고 있다. 그 방안의 하나로 지목되는 것이 $''$기업 건전성 지수$''$이다. 기업 건전성 지수는 경영자의 기업관리 및 투자자의 기업평가에 동일하고 유용하게 쓰일 수 있는 재무적 접근법이다. 본 논고에서는 기업 건전성지수에 대한 개념, 활용방안, 회계조정 그리고 지표의 진정한 효과에 대하여 설명하고자 한다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.7
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• pp.610-616
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• 2008

For this study, the forming analyses and body strength tests of TBP were performed on the main pipe size 150A(KS D3507, KS D 3576 10S). The branched pipe sizes utilized were 25A, 32A, 40A, 50A, 65A, 80A, 100A and 125A. A general FEM program, ABAQUS, was used as the forming analyses method of TBP. Using the results, the strength of TBP was then tested in order to determine the safety of TBP when the working pressure was applied. The results indicate that TBP may be safely used in water-based fire protection pipe systems in terms of the strength.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.222-222
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• 2011

안전한 수질의 용수를 안정적으로 공급하기 위해 대단위 농업단지를 중심으로 농업용 관수로 건설이 고려되고 있는 환경에서 보다 경제적으로 관수로를 건설하기 위한 연구가 수행되었다. 관수로의 최적 관경설계는 전통적으로 비선형성을 고려하여야 하므로 수리학적 해석모형과 추계학적 탐색기법을 이용한 연구가 수행되었다. 그러나 본 연구에서는 비선형성을 가진 최적 관경시스템의 선형화를 시도한 후, 농지이용에 따른 대표작물에 대한 설계용수량을 사용한 농업용 관수로 관경 최적화를 시도하였다. 제안된 모형을 이용하여 농지의 크기, 작물의 형태, 동수경사선의 기울기에 따라 적합한 관경을 산정하였으며, 그 결과를 이용한 설계 표준화를 시도하였다. 표준화된 설계지침을 이용하면 향후 보다 편리하게 농업용 관수로를 설계할 수 있을 것으로 판단된다. 또한 실제 관수로에의 적용성을 입증하기 위해 실제 건설되는 농업단지의 설계에 제안된 모형을 이용하고, 시행착오법으로 산정된 결과와 비교하여 그 경제성을 입증하였다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.11
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• pp.781-787
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• 2010

To improve the efficiency of piping, recently the pre-fabrication piping system has been introduced, and much attention has been paid to TBPs which can replace Tee-joint. Forming and forming analysis on TBPs made from Carbon steel pipes for pressure service(KS D 3562 Sch40) and Stainless steel pipes(KS D 3576 20S) have been conducted to determine working pressure. Forming and forming analysis objects are $32A{\times}25A$, $40A{\times}25A$, $40A{\times}32A$, $50A{\times}25A$, $50A{\times}32A$, $50A{\times}40A$ TBPs.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.5
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• pp.351-356
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• 2008

In this study, we had the stress analyses of TBP used in Tall Building and determined the working pressure of TBP. We knew the four fact. First, the place acted maximum stress is axial direction of branched part. Second, working pressure is more than 2.0 MPa. Third, stress in branched part is less than yielding strength at hydrostatic test pressure. Fourth, the ratio(stress/yielding stress at hydrostatic test pressure) is $0.4{\sim}0.6$(KS D 3562 Sch 40), $0.3{\sim}0.4$(KS D 3576 20S).