• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제4권5호
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• pp.147-152
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• 2015

일반적으로 병렬 이벤트구동 시뮬레이션의 대표적 동기화 방법으로는 비관적 동기화 방식과 낙관적 동기화 방식이 있는데, 본 논문에서는 예측기반 병렬 이벤트구동 로직 시뮬레이션에서 이 두 가지 동기화 방식들을 혼용한 간헐적 동기화를 통한 시뮬레이션 성능 향상 기법을 제시한다. 제안되는 간헐적 동기화 방식은 예측기반 병렬 이벤트구동 로직 시뮬레이션에서 자주 일어나는 틀린 예측과 연관된 체크포인트 오버헤드 및 재실행 오버헤드를 최소화할 수 있어 시뮬레이션 성능 향상에 매우 효과적인데, 이를 다양한 실제 디자인들에 적용한 실험을 통하여 확인할 수 있었다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 추계 학술대회논문집
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• pp.18-21
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• 2006

This paper investigates LES of turbulent combustion flow based on 2-scalar flamelet approach, where a G-equation and a conserved scalar equation simulate a propagation of premixed flame and a diffusion combustion process, respectively. The turbulent SGS modeling on these flamelet combustion approach is also researched. These LES models are applied to an industrial flows in a full scale gasturbine combustor with premixed and non-premixed flames. The numerical results predict the characteristics of experiment temperature profiles. Unsteady features of complex flames in combustor are also visualized.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제3권3호
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• pp.73-80
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• 2014

본 논문에서는 이벤트구동 HDL 시뮬레이션에서 시뮬레이션 실행 시간 단축을 위한 인크리멘탈 시뮬레이션 방법을 제시한다. 일반적으로 시뮬레이션 과정은 일련의 반복적인 설계수정들과 동반되어 반복적으로 일어난다. 인크리멘탈 시뮬레이션은 이와같은 반복적인 시뮬레이션에서 설계수정 전의 시뮬레이션 결과를 이용하여서 설계수정 후에 진행되는 시뮬레이션의 수행 시간을 단축할 수 있는 효과적인 시뮬레이션 방법이다. 본 논문에서 제안된 인크리멘탈 시뮬레이션 방법의 유용함은 다양한 실제 디자인들에 적용한 실험을 통하여 확인할 수 있었다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제29회 KOSCI SYMPOSIUM 논문집
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• pp.109-116
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• 2004

Through analysing the influence of steam flow direction on the liquid formation and motion behavior in the condenser shell side, the physical model for existing numerical simulation program of condenser is improved by introducing the correlations for flow resistance and condensation heat exchange coefficient in which the influences of steam flow direction are considered according to the available experimental data. Thus a more suitable and general condenser simulation approach is presented and a new condenser calculation program is developed. With the experimental data of a pannier- arrangement experimental condenser, the adaptability of the new condenser simulation approach is verified. General characteristics of this type of condenser are also revealed.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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• pp.355-357
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• 2012

A probability density function (PDF) approach to account for turbulence-chemistry interaction in the context of large eddy simulation (LES) based simulation of scramjets is developed. To solve the high-dimensional joint-composition PDF transport equation robustly, the semi-discrete quadrature method of moments (SeQMOM) is recently proposed [1]. The SeQMOM approach addresses key numerical issues in LES related to the inaccuracies in computing filter-scale gradients, enabling an efficient and numerically consistent solution of the PDF transport equation. The computational tool is used to simulate a cavity-stabilized Mach 2.2 supersonic combustor.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.929-934
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• 2005

The complex and dynamic job nature and the ever-changing working environment of construction projects inevitably present uncertainties to construction operations. Identification, evaluation and control of uncertainties constitute main elements of risk management and critical tasks of project management in construction. This paper is focused on application of a simplified discrete-event simulation approach in management of schedule-overrun risks, each being the combination of the occurrence probability of an uncertain interruptive factor and its potential consequence in terms of time delay. A case study observed from a concreting operation in Hong Kong is converted into a simulation model and analyzed with an in-house-developed simulation package for demonstrating how the proposed approach can be implemented to manage multiple schedule-overrun risks on construction projects.

• 대한교통학회지
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• 제34권6호
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• pp.548-559
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• 2016

최근 교통안전과 공공보건에 대한 관심이 증대됨에 따라 친환경 교통시스템의 설계 및 구축의 필요성도 높아지고 있다. 교통의 패러다임 변화 및 환경성 관심의 증대로 공공보건 및 교통안전 증진을 위한 교통관리전략이 요구됨에 따라 본 연구에서는 이를 평가할 수 있는 시뮬레이션 연계기반의 평가방법론을 개발하는 연구를 수행하였다. 이를 위해 교통시뮬레이션 및 환경시뮬레이션을 연계하여 교통관리전략의 효과를 미시적 및 거시적 관점으로 통합평가 할 수 있는 분석 툴과 절차를 제시하였다. 본 연구에서 제안하는 방법론을 교통정온화기법을 바탕으로 하는 속도관리전략의 효과를 평가하는데 적용하여 분석사례를 제시하였다. 분석결과 시케인을 적용한 시나리오가 종합적으로 기존 미설치의 경우보다 우수한 것으로 도출되어 기존의 교통환경을 개선할 수 있을 것으로 판단된다. 따라서 무분별한 과속방지턱 보다는 효과적인 속도감속유도를 위한 타 시설을 고려할 필요가 있다. 본 연구의 결과는 공공보건 및 교통안전 등 다양한 요소를 고려한 교통관리전략 수립 시 정책결정자의 의사결정을 효과적으로 지원할 것으로 판단된다.

• Wind and Structures
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• 제27권3호
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• pp.199-211
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• 2018

This paper deals with wind fragility and risk analysis of high rise buildings subjected to stochastic wind load. Conventionally, such problems are dealt in full Monte Carlo Simulation framework, which requires extensive computational time. Thus, to make the procedure computationally efficient, application of metamodelling technique in fragility analysis is explored in the present study. Since, accuracy by the conventional Least Squares Method (LSM) based metamodelling is often challenged, an efficient Moving Least Squares Method based adaptive metamodelling technique is proposed for wind fragility analysis. In doing so, artificial time history of wind load is generated by three wind field models: i.e., a simple one based on alongwind component of wind speed; a more detailed one considering coherence and wind directionality effect, and a third one considering nonstationary effect of mean wind. The results show that the proposed approach is more accurate than the conventional LSM based metamodelling approach when compared to full simulation approach as reference. At the same time, the proposed approach drastically reduces computational time in comparison to the full simulation approach. The results by the three wind field models are compared. The importance of non-linear structural analysis in fragility evaluation has been also demonstrated.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1359-1363
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• 2009

The object of this research is to develop a simulation system for earthmoving operations in consideration of the impact of congestion in-between equipment and existing traffic flow around the site. The congestion in-between equipment and traffic flow affect work productivity. The conventional discrete event simulation, however, has limitations in simulating the flow of construction equipment. To consider the impact of congestion in-between equipment and existing traffic flow, in this paper, a multi-agent based simulation model that can realize characteristics of truck behavior more accurately to consider the impact of congestion was proposed. In this simulation model, multiple agents can identify environmental changes and adapt themselves to the new environment. This modeling approach is a better choice for this problem since it describes behavioral characteristics of each agent by sensing changes in dynamic surroundings. This study suggests a detailed system design of the multi-agent based simulation system.

• Journal of International Society for Simulation Surgery
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• 제1권1호
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• pp.16-18
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• 2014

The orbit has a very special anatomical structure. The complex anatomical structure should be restored when we encounter the patient with orbital wall fracture. Unless these specific anatomy were reconstructed well, the patient should suffer from various complications such enophthalmos, diplopia or orbital deformity. In addition, because the patient has a his own specific orbital shape, individualized approach will be necessary. The aim of this trial is to try to restore the original orbit anatomy as possible 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. In order to restore the missing skipped images between the cuts of CT data because of the thinness of the orbital walls, we manipulated the DICOM data for imaging the original orbital contour using the preoperatively manufactured mirror-image of the RP model. And we fabricated Titanium-Medpor to reconstruct three-dimensional orbital structure intraoperatively. This prefabricated Titanium-Medpor was then inserted onto the defected orbital wall and fixed. Three dimensional approach 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.