• Proceedings of the KOR-KST Conference
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• 1998.10a
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• pp.41-41
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• 1998

ITS틀 내의 한 분야인 도로교통정보체계 (ATIS: Advanced Traveler Information system)는 실시간 교통정보를 운전자에게 직접 제공하는 것으로서, 이를 위해 매 순간마다 가로망에 배정되는 교통량 및 통행시간을 예측할 수 있는 범용의 동적 통행배정모형(dynamic route choice model)의 개발이 필히 수반되어야 한다. 본 연구에서는 ITS사업에서 필수적으로 수반되어야 할 최적 제어이론에 의한 동적 통행 배정모형을 ATIS의 핵심 소프트웨어로 응용하기 위해 기존 연구성과를 발판으로, 순간 동적 통행 배정모형(Ran, Boyce &LeBlanc, 1993)의 통행제약조건인 링크통행함수, 특히, 과부하 시 엘켈릭의 일반식의 파라메터를 조정, 적용하여, 서울시 강남지역의 실제 가로망의 사례연구를 통해 지체식의 각각의 파라메터에 따른 결과를 O/D에 따른 통행시간, 링크통행시간, 혼잡도를 중심으로 비교 평가하여, ATIS의 핵심 소프트웨어로서 순간 동적 통행배정을 통해 보다 현실여건을 잘 반영할 수 있는 링크 통행 성능 함수를 도출하였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.9
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• pp.1365-1371
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• 2013

We have introduced two dimensional cluster aggregation model to explain theoretically two phase coexistence phenomena such that adsorption is increased sharply discontinuous in particular pressure on the surface. And then, we have derived adsorption isotherms by applying fundamental statistical thermodynamics and Lagrange multipliers to the our model. By analyzing the our derived adsorption isotherms, we can explain well qualitatively that two phase coexistence on the surface adsorption would be a phenomena that occurs with the strong attractive forces between the adsorbed particles.

• Journal of the Korean Society of Radiology
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• v.12 no.2
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• pp.225-231
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• 2018

Recently, new teaching methods for communicating with teachers and students have been emerged according to the trends of decreasing the school-age population and the development of the mass media. We have applied teaching-learning model based on the flip learning to the college students in this work. As a result of the test for the customized flipped learning teaching-learning model in pre-class, the attendance rate of the major subject was 92.3% whereas that in liberal arts courses other than majors revealed 87.6%. This result for attendance rate shows that first year students in the radiology department have been actively participated in pre-class of the major subject than that of the liberal arts curriculum. From comparing the differences between the study group that was applied flipped learning in class and the non-applied group, the research group showed higher scores in knowledge, skills, and attitudes than the comparative group. In addition, more than 90% of the learners improved their responsibility, problem solving ability, creative thinking, cooperative ability, and communication ability through this learning program. From the test for the difference in the role of radiologists in the post class, the mean score was 4.40 for the group applied the teaching-learning model while that for non-applied group was 2.10. Hence, from such results, we see that this teaching-learning model is appropriate and needs to be extended to cultivate basic skills in radiology and relevant vocational education.

• Journal of the Korean Data and Information Science Society
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• v.25 no.4
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• pp.697-703
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• 2014

Deal-or-No-Deal game is a famous TV show program of NBC, USA, which is composed of 10 stages at most. At each stage from the first and the ninth, a banker suggests a deal price to participants. In this paper, we intend to reveal the banker's deal price model using a constrained linear model and quadratic program. As results, we provide a linear model in relation to the deal price at each stage and then show using simulation data that the deal price is equal to the nearest integer of the value to be obtained by the provided linear model.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.4
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• pp.64-76
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• 1999

In this paper hydroelastic experimental techniques of very large floating offshore structures are suggested based on the model test carried out in the UOU Ocean Engineering Wide Tank. The prototype is a box-shaped floating structure with length of 300m, breadth of 60m, depth of 2m and draft of 0.5m and longitudinal bending rigidity as $4.87{\times}10^{10}kgm^2$. The scale ratio is 1/42.857. The model is realized by aluminum square pipes with the section dimension of $20mm{\times}20mm$. The numbers of longitudinal and transverse pipes are 7 and 35 respectively. Heave motions at selected points are measured with potentiometers and bending moments with strain gages.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.254-254
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• 2015

본 연구에서 사용한 부유식방파제는 상치의 공기주입량에 따라 흘수심을 조절할 수 있으며, 부유식방파제 입사면과 투과면에 하부슬릿을 두어 입사파랑의 제어가 가능하도록 고안하였다. 또한, 수리 모형실험에서는 카테너리(catenary) 계류시스템의 계류각 변화에 따른 장력특성을 분석하였다. 일반적으로 계류시스템은 계류점, 계류형상 및 인장정도에 따라 구분된다. 본 연구에서는 부유식방파제의 6자유도 운동 중 2차원운동에 따른 장력특성 분석을 위하여 4점 계류를 채택하였으며, 계류형상은 일정 동요량을 허용하지만 안전성이 높은 카테너리형을 적용하였다. 수리모형실험을 통하여 투수성 부유식방파제의 장력특성을 분석하고, 입사파랑 변화에 따른 계류시스템의 안전성을 분석한 결과, 투수성부유식방파제는 계류각 전 구간에서 무공형부유식방파제에 비하여 최대장력이 낮게 측정되었으며 안전성이 확보되었다.

• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.2
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• pp.1-15
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• 1997

This paper presents substructural identification methods for the assessment of local damages in complex and large structural systems. For this purpose, an auto-regressive and moving average with stochastic input (ARMAX) model is derived for a substructure to process the measurement data impaired by noises. Using the substructural methods, the number of unknown parameters for each identification can be significantly reduced, hence the convergence and accuracy of estimation can be improved. Secondly, the damage index is defined as the ratio of the current stiffness to the baseline value at each element for the damage assessment. The indirect estimation method was performed using the estimated results from the identification of the system matrices from the substructural identification. To demonstrate the proposed techniques, several simulation and experimental example analyses are carried out for structural models of a 2-span truss structure, a 3-span continuous beam model and 3-story building model. The results indicate that the present substructural identification method and damage estimation methods are effective and efficient for local damage estimation of complex structures.

• Journal of Korean Society of Transportation
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• v.20 no.3
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• pp.105-113
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• 2002

As the number of pedestrian accident increases, the reconstruction of an accident becomes important to find the source of the fault. Generally, accidents are reconstructed by the intuition of experts or primitive physics. A reconstruction method is proposed using sophisticated optimization technology. At first, a dynamic simulation model is established for the accident environment. Occupant analysis for automobile crashworthiness is employed. The situation before an accident is identified by optimization. The impact velocity and the position of the pedestrian are utilized as design variables. The design variables are found by minimizing the difference between the simulation and the real accident. The optimization process is performed by linking an occupant analysis program MADYMO to an optimization program VisualDOC. Since the involved analysis is dynamics and highly nonlinear, response surface method is selected for the optimization process. Problems are solved for various situations.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1991.07a
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• pp.1-5
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• 1991

1572년도에 발표된 두 수치모형 중 하나인 쌍곡형모형은 조석수치모형에 사용되는 수심적분된 두 방정식 (연속방정식과 운동량보존식)과 유사한 형태의 기본식을 사용하는데, 최초에 Ito and Tanimoto (1972)가 발표한 수식을 파의 군속도가 파속에 일치하지 않는 해역에서 오차가 발생한다.(중략)

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.66-66
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• 2023

대규모 댐의 운영으로 인한 인위적인 유량 교란은 물리 기반 수문모형의 정확한 하천유량 모의를 어렵게 만든다. 이러한 한계를 극복하기 위해, 상류의 자연형 유역 모의를 위한 물리 기반 수문모형 Variable Infiltration Capacity model과 댐 운영 모의를 위한 딥러닝 기반 모델을 결합한 하이브리드 모델링 프레임워크를 개발하였다. 본 연구는 수도권의 주요 상수원이자 대규모 댐들이 존재하는 팔당댐 유역을 대상으로, 물리 기반 수문모형만을 기반으로 구축한 단일 및 계단식 구조의 모델과 하이브리드 모델의 예측 성능을 비교하였다. 2015년부터 2019년까지의 검증 기간 동안, 하이브리드 모델, 단일 및 계단식 구조 모델의 Nash-Sutcliffe Efficiency는 각각 0.6410, -0.1054 그리고 0.2564로 하이브리드 모델의 성능이 가장 높은 것으로 나타났다. 이는 머신러닝 알고리즘을 이용한 댐 운영 고려가 정확한 하천유량 평가를 위해서 필수적임을 시사한다. 이러한 결과는 수자원 관리, 홍수 예측 등 다양한 분야에서 활용될 수 있으며, 특히 미래의 지속 가능한 물 관리를 위해 실무자에게 정확한 자료를 제공하는 데 기여할 수 있다.