• 한국시뮬레이션학회논문지
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• 제4권1호
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• pp.113-119
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• 1995

In 3D computer graphics, fractal techniques have been applied to terrain models. Even though fractal models have become popular for recreating a wide variety of the shapes found in nature, a specific 3D terrain model such as Uleung Island could not be formulated by statistical fractals easily owing to the random effects. However, by locating the midpoints on the edges and the surface of a specific terrain such as Uleung Island, a similar shape of the terrain model can be simulated. This paper shows the way of simulating 3D Uleung Island terrain model by the statistical fractals wherein the subdivision algorithm is used.

• 한국의상디자인학회지
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• 제8권2호
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• pp.27-35
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• 2006

We studied the 3D simulating shapes of the flared skirt using NARCIS-Drape Simulation software made in Korea D&M FT. The experimental conditions were made of three types of cuttings (lengthwise, crosswise, 45 bias) and polyester fabrics for flared skirt (light, medium, heavy) and different simulating repetitions (1, 2, ${\cdots}$, 9, 10 times). We accomplished some experimental data on the 3D simulating shapes of the flared skirt made by different conditions. The 3D simulation shapes of the flared skirts were gradually getting stabilized from 5 repetitions. And the length of skirts and the width and depth of hems diminished lower by degrees as the simulating repetitions. It is considered that the simulating repetition for the flared skirt was appropriate in the range of 8 to 10 times. But it was not reasonably showed that the difference in the drape of the flared skirt was made by different cuttings and fabrics.

• Journal of International Society for Simulation Surgery
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• 제1권2호
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• pp.99-102
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• 2014

The skull defect can be made after the trauma, oncologic problems or neurosurgery. The skull reconstruction has been the challenging issue in craniofacial fields for a long time. So far the skull reconstruction with autogenous bone would be the standard. Although the autogenous bone would be the ideal one for skull reconstruction, donor site morbidity would be the inevitable problem in many cases. Meanwhile various types of allogenic and alloplastic materials have been also used. However, skull reconstruction with many alloplastic material have produced no less complications including infection, exposure, and delayed wound healing. Because the 3D printing technique evolved so fast that 3D printed titanium implant were possible recently. The aim of this trial is to try to restore the original skull anatomy as possible using the 3D printed titanium implant, based on the mirrored three dimensional CT images based on the computer simulation. Preoperative computed tomography (CT) data were processed for the patient and a rapid prototyping (RP) model was produced. At the same time, the uninjured side was mirrored and superimposed onto the traumatized side, to create a mirror-image of the RP model. And we fabricated Titanium implant to reconstruct three-dimensional orbital structure in advance, using the 3D printer. This prefabricated Titanium-implant was then inserted onto the defected skull and fixed. Three dimensional printing technique of titanium material based on the computer simulation turned out to be very successful in this patient. Individualized approach for each patient could be an ideal way to manage the traumatic patients in near future.

• 한국자동차공학회논문집
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• 제16권6호
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• pp.65-73
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• 2008

The purpose of this study is development of universal engine model for integrated Hybrid Electric Vehicle (HEV) simulator and a optimization of engine model. The engine model of this study is based on the MATLAB Simulink for universal and include engine fuel economy technologies for HEV. Various engine fuel economy technologies for HEV is estimated by commercial engine 1-D simulation program - WAVE. And, the 1-D simulation model of base version is compared with engine experiment result. The analyzed engine technologies with 1-D simulation are Dual-CVVT, Atkinson-Cycle and Cylinder-Deactivation System. There are improvement of fuel economy and power performance with Dual-CVVT model at part load and full load, pumping loss reduction with Cylinder-Deactivation System at idle and regeneration. Each estimated technologies are analyzed by 1-D simulation on all operation region for base data to converse simulink. The simulink based engine model maintains a signal with ECU for determination of engine operation point.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 학술대회 논문집
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• pp.92-94
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• 2003

In superconductive digital logic circuits, D2 cells can be used to compose a decoder an important component of an Arithmetic Logic Unit (ALU). In this wor, we simulated D2 cell by using WRspice. D2 cell has one input, one switch input, and two outputs (output1 and output2). D2 cell functions in such way that output1 follows the input and output2 is the complement of the input data, when the switch input is "0, ". However, when there is a switch input "1, " the opposite output signals are generated. In this paper, we optimized a D2 cell by using WRspice, and obtained the minimum margin of 26%. Our optimized D2 cell will play a key role in the ALU fabrication.the ALU fabrication.

• 한국시뮬레이션학회논문지
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• 제19권2호
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• pp.1-8
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• 2010

최근 컴퓨터 하드웨어 및 3D 그래픽의 기술 발전으로 많은 사용자들이 실제와 유사한 3D 그래픽으로 표현되는 것에 관심을 가지고 있다. 이러한 사용자들의 요구가 증대됨에 따라 많은 분야에서 3D 시뮬레이션이 개발 보급되고 있다. 본 논문에서는 3D 그래픽 기술을 활용하여 화재시의 건물 내에서 사람들이 대피하는 시뮬레이션 시스템을 설계하고 구현한다. 본 논문에서는 사람이 화재 시 건물을 탈출할 때 인공지능을 갖기 위해 A* 알고리즘을 사용하였으며, 화재 시에 사람의 탈출에 영향을 미치는 열과 연기를 고려하여 각 사람의 탈출 속도를 계산한다. 본 논문에서 제안하는 대피 시뮬레이션의 효과를 입증하기 위해 실제 건물환경을 모델링하여 적용하였다. 실험결과들을 통해서 본 논문에서 제안한 방법을 통하여 연기의 농도가 짙어질수록 사람의 탈출속도가 감소하는 것과 온도와 연기 농도에 의해 사람이 피해를 입고 사망하는 것을 확인할 수 있다.

• 한국수자원학회논문집
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• 제57권7호
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• pp.451-460
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• 2024

빈발하고 있는 도시 지역 침수 피해의 원인을 분석하고 대책을 수립하기 위하여 합리적인 도시 침수 모의 방법을 적용할 필요가 있다. 기존의 국내 연구들은 하수 관거의 맨홀 범람과 하천의 범람 결과를 2차원 범람 유동 모의 모형에 입력하여 침수 모의를 수행하였다. 그렇지만 하천과 맨홀 범람의 침수 모의는 결합하여 분석하는 것이 합리적이다. 이 연구에서는 XP-SWMM을 구성하는 TUFLOW 모듈의 1-2차원 연계 기능을 사용하여 하천과 제내지의 복합 침수 모의를 수행하였다. 해당 방법을 2022년 9월 5일과 6일 태풍 힌남노로 인한 내수 침수와 하천 범람이 동시에 발생한 경상북도 포항시 냉천 하류 유역에 적용하여 적절성을 검증하였다.

• Nuclear Engineering and Technology
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• 제54권9호
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• pp.3567-3579
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• 2022

This paper provides an assessment of fluid transport and mixing processes inside the primary circuit of the test facility ROCOM through the numerical simulation of Test 2.1 with the system code ATHLET. The experiment represents an asymmetric injection of cold and non-borated water into the reactor coolant system (RCS) of a pressurized water reactor (PWR) to restore core cooling, an emergency procedure which may subsequently trigger a core re-criticality. The injection takes place at low velocity under single-phase subcooled conditions and presents a major challenge for the simulation in lumped parameter codes, due to multidimensional effects in horizontal piping and vessel arising from density gradients and gravity forces. Aiming at further validating ATHLET 3-D capabilities against horizontal geometries, the experiment conditions are applied to a ROCOM model, which includes a newly developed horizontal pipe object to enhance code prediction inside coolant loops. The obtained results show code strong simulation capabilities to represent multidimensional flows. Enhanced prediction is observed at the vessel inlet compared to traditional 1-D approach, whereas mixing overprediction from the descending denser plume is observed at the upper-half downcomer region, which leads to eventual deviations at the core inlet.

• Structural Engineering and Mechanics
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• 제32권1호
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• pp.55-69
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• 2009

A quasi ideal importance sampling simulation method combined in the conditional expectation is proposed for the structural reliability estimation. The quasi ideal importance sampling joint probability density function (p.d.f.) is so composed on the basis of the ideal importance sampling concept as to be proportional to the conditional failure probability multiplied by the p.d.f. of the sampling variables. The respective marginal p.d.f.s of the ideal importance sampling joint p.d.f. are determined numerically by the simulations and partly by the piecewise integrations. The quasi ideal importance sampling simulations combined in the conditional expectation are executed to estimate the failure probabilities of structures with multiple failure surfaces and it is shown that the proposed method gives accurate estimations efficiently.

• Journal of International Society for Simulation Surgery
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• 제1권2호
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• pp.67-70
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• 2014

3-D medical image reconstruction technique using computer simulation technology has been used in the knowledge of the anatomical features and the biomechanical characteristics with the advancement of computer hardware and software. Especially, the use of 3-D image reconstruction technique in orthopaedics demonstrates that this technique is useful to improve surgical technique as well as to help inform the knowledge of shoulder joint anatomy. The purpose of this article is to introduce the utilization of 3-D image technology in shoulder surgeries.