시뮬레이션의 과학적 지위 - 시뮬레이션이 실험을 대신할 수 있는가? -

고인석 서강대학교 철학연구소 2024 철학논집 Vol.77 No.-

컴퓨터 시뮬레이션은 대상의 아직 확인되지 않은 속성을 파악하는 탐구의효과적 도구로 인정받으며, 그럼으로써 근대과학의 핵심 방법론인 실험에 상응하는 과학적 지위를 지니는 것처럼 보인다. 본고는 컴퓨터 시뮬레이션이 실로 실험과 동 등한 인식적 가치를 지니는지를 검토함으로써 현재 사회에서 다양한 의사결정을 보 조하는 도구로 활용되는 컴퓨터 시뮬레이션의 과학적 지위를 평가한다. 이 검토는 특정한 실험을 그것을 모의하는 시뮬레이션으로 인식적 손실 없이 온전히 대체할 수 있을지 검토하는 방식으로 진행된다. 이 검토에서, 원자 구조에 관한 지식의 진 보를 가져온 러더포드의 알파입자 산란 실험은 그러한 대체가 불가능한 경우로, 반 면 전산유체역학의 현상들에 관해서는 대체가 가능한 것으로 평가된다. 본고는 후 자의 경우에 시뮬레이션이 견고한 이론들을 활용하는 추론의 속성을 지닌다는 것, 그럼에도 불구하고 그것이 타당한 실험이 제공하는 것과 동등한 인식적 소득을 산 출할 수 있음을 밝힌다. Computer simulations are effective tool in the quest for yet unidentified properties of the world, and as such, they seem to have a status equivalent to scientific experimentation, the core methodology of modern science. This paper discusses the epistemic status of computer simulations, which are utilized as tools to aid in a variety of decision-making in our society, by appraising whether computer simulations have the epistemic value of experiments. This appraisal proceeds by examining whether a set of simulations can replace the corresponding experiment without epistemic loss. Rutherford's α particle scattering experiment, which led to advances in our knowledge of atomic structure, is analyzed to be a case where such a substitution is not possible, while phenomena in computational fluid dynamics are estimated to be the cases where substitutions are practical. In the latter case, it is shown that simulation has the properties of inference that employs robust theories, and that it nevertheless yields epistemic gain equivalent to that provided by valid experiments.

화재시뮬레이션

김상문(Sang Moon Kim),윤상열(Sang Youl Yoon),김경천(Kyung Chun Kim) 한국가시화정보학회 2006 한국가시화정보학회지 Vol.4 No.1

Fire simulation has been developed for decades to analyze fire cases and provide a tool to study fundamental fire dynamics and combustion. There are three way of fire simulation which are a full scale simulation, an experimental simulation and a computational simulation. In case of a full scale simulation, because a higher cost, a higher risk, more efforts are needed, a demand for it has been decreased. But recently a demand for an experimental simulation and a computational simulation has been increased. A computational simulation has several advantages; lower cost, short period, many case studies, more visual results, a quantitative result and etc. FDS(Fire Dynamics Simulator) which has been developed in BFRL (Building and Fire Research Laboratory), NIST(National Institute of Standards and Technology) is a popular world wide code for fire simulation. Lack of accurate predictions by the model could lead to erroneous conclusions with regard to fire safety. All results should be evaluated by the informed judgment of the qualified user.

DEXSim: an experimental environment for distributed execution of replicated simulators using a concept of single simulation multiple scenarios

Choi, Changbeom,Seo, Kyung-Min,Kim, Tag Gon SAGE Publications 2014 Simulation Vol.90 No.4

<P>This paper presents an efficient and scalable experimental environment for distributed execution of replicated simulators. By taking a performance-centered approach, the proposed technique makes the best use of distributed hardware resources for faster data collection. Accordingly, the primary contribution of this work is to describe how the environment improves scalability and utilizes distributed hardware resources efficiently. To do this, we suggest a new concept of single simulation multiple scenarios and propose a distributed execution simulation framework regarding the following three aspects: (1) layered architecture model design; (2) protocol definitions interacting with them; and (3) framework implementation. The proposed model architecture and protocol definitions guarantee a straightforward structural scalability and an efficient load-balanced utilization between hardware resources. Moreover, the framework operates simulation execution automatically without users’ extra work. In order to prove the efficiency of the proposed framework, we performed three extensive experiments with different models, that is, different systems. The experimental results show that simulation performance increases proportionally with the number of hardware resources, minimizing the overhead of the proposed framework’s utilization.</P>

크리깅과 타부탐색법을 이용한 운전석 에어백의 최적설계

김정환(Jeung-Hwan Kim),이권희(Kwon-Hee Lee),주원식(Won-Sik Joo) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.4

In the proto design stage of a new car, the performance of an occupant protection system is often evaluated by CAE instead of the real test. CAE predicts and recommends the appropriate design values hence reducing the number of the real tests. However, the existing researches using CAE in predicting the performances do not consider the uncertainties of parameters, in which inconsistency between the actual test results and CAE exists. In this research, the optimization procedure of a protection system such as airbag and load limiter is suggested for the frontal collision. The DACE modeling known as Kriging interpolation is introduced to obtain the meta model of the system followed by the tabu search method to determine a global optimum. Finally, the distribution of a suggested design is determined through the Monte-Carlo Simulation.

가청화를 이용한 소형 다목적 홀의 음향성능 개선평가

김재수 한국문화공간건축학회 2011 한국문화공간건축학회논문집 Vol.- No.35

Recently, in accordance with the development of culture and the improvement of citizens' consciousness, it is the real state that the construction of small multi-purpose hall where various cultural events is on increasing. However, because the most of such small multi-purpose hall is design and constructing without consideration about the acoustic requisite, many acoustic defects are occurring. Especially, since the finishing material of a strong sound-absorption was imprudently used to the most of such small multi-purpose hall built in the domestic country, as the diffusion and reflection of sound are not properly achieving, and because the reverberation of sound is very low, in case when playing a musical instrument, the acoustic defects are arising, as the sound is too dull and stiff, it is hard to appreciate a music with a sufficient tone, and so on, it is the situation that the performance improvement is very urgently requiring. On such point of view, for the object of such small multi-purpose hall, this study has attempted to grasp the satisfaction degree on acoustic performance using the auralizational technique about small multi-purpose hall on both before-improvement·after-improvement on acoustic performance. It is considering that such study result could be utilized as the useful material that enables them to secure the construction cost reduction effect and improve the acoustic performance by prediction·control its acoustic problem, in case when a construction or renovation of the similar small multi-purpose hall in the future.

확률실험 환경에서 초등학교 수학영재 학생과 일반 학생의 확률 탐구 특성 비교

이경화,문성재,고은성,최성이,안민웅 대한수학교육학회 2019 학교수학 Vol.21 No.2

The law of large numbers is the main principle that describes the relationship between mathematical and statistical probability. To understand the law of large numbers, it is necessary to grasp pattern and variability at the same time. This study sets the inference of pattern and variability for the two axes of analysis, and analyzes the learning patterns of probability concept of mathematically gifted students and non-gifted students in the physical and computer simulation situations, and compares the characteristics that appear in the two groups. This study found that in both situations, mathematically gifted students showed a higher level of understanding compared to non-gifted students, and in computer simulation situations, a rise in understanding level was observed in both groups. Meanwhile, it was observed that most students, whether or not they were mathematically gifted, failed to recognize chance variability. Based on these results, this study presents a basic perspective to establish learning paths suitable for student's level. 큰 수의 법칙은 수학적 확률과 통계적 확률 사이의 관계를 설명하는 주요한 원리이다. 큰 수의 법칙을 이해하기 위해서는 시행 횟수를 늘림에 따라 나타나는 분포의 전체적인 경향과 개별 시행에서 나타나는 변이성을 동시에 파악해야 할 필요가 있다. 이에 본 연구는 중심에 의한 추론과 변이성에 대한 추론을 분석의 두 축으로 하여, 물리적 상황과 컴퓨터 시뮬레이션 상황에서 나타나는 수학영재 학생과 일반 학생의 확률개념 학습 양상을 분석하고 두 집단에서 나타나는 특징을 비교한다. 연구 결과, 물리적 상황에서 수학영재 학생은 대체적으로 일반 학생에 비해 더 높은 이해수준을 보여주었으며, 일반 학생의 절반 정도가 경향성의 파악에 실패하는 모습을 보였다. 컴퓨터 시뮬레이션 상황에서 두 집단의 이해수준이 모두 상승하였으나, 많은 일반 학생이 관계적 이해수준에는 도달하지 못하는 모습을 확인할 수 있었다. 한편, 변이성에 대한 인식과 관련하여, 대부분의 수학영재 학생과 일반 학생이 우연변이성의 인식에 실패하는 현상이 관찰되었다. 이러한 결과를 바탕으로 본 연구는 각각의 학생의 수준에 적합한 학습경로를 설정하는 데 필요한 기초자료를 제시하였다.

CFD모델과 풍동실험을 이용한 복잡지형에서의 기류해석

문기영,김석철,신구용,조경학,윤정임,황규석,길용식 한국풍공학회 2009 한국풍공학회지 Vol.13 No.3

Winds over a complex terrain were analyzed using wind tunnel and several computational fluid dynamics (CFD) models. A mountain area adjacent to a shoreline was chosen in a Southern Korea Peninsula for study. Two different CFD models were used for simulating flows: one is an FVM code with Virtual Boundary Method(VBM) using LES for sub-grid turbulence, and the other is a commercial package implemented with 4 different RANS (Reynolds Averaged Navier-Stokes Equations) turbulence models. The CFD simulations were compared with wind tunnel data at several locations where wind speeds were greatly enhanced or reduced due to the surrounding topographic features. The agreement between the CFD simulations and the wind tunnel experiments were good, the correlation coefficients ranging 0.890 ~ 0.965. The FVM code was excellent of which correlation coefficient was 0.965. 자연지형에 의한 기류 변화를 CFD 모델과 풍동실험을 통하여 비교 연구하였다. 해안에 인접한 남부 산악지형을 대상으로 풍동실험과 몇 종류의 CFD 모델 시뮬레이션을 수행하였다. 사용한 CFD 모델은 2 가지로, 하나는 LES 난류모델을 사용하는 가상경계기법을 활용한 유한체적법(Finite Volume Method, FVM) 코드와 또 하나는 4 가지 RANS 난류모델이 선택사양으로 제공되는 상업용 CFD 모델이다. 지형에 의해 풍속이 증가되는 지점과 감소되는 지점에서 수직풍속분포를 직접 비교하고 상관도를 구하였다. CFD 모델과 풍동실험과의 상관도()는 0.890 ~ 0.965로 매우 높게 나타났으며, CFD 모델 중 VBM LES CFD 모델은 상관도 0.965로 나타나 풍동실험을 가장 잘 모사하는 것으로 분석되었다.

전기자동차용 Ni/MH Battery의 자기방전율 평가를 위한 컴퓨터 시뮬레이션의 활용

정도양,김명규,박성용,김선욱,Jung Do Yang,Kim Myung Gyu,Park Seong Yong,Kim Sun Wook 한국전기화학회 2001 한국전기화학회지 Vol.4 No.2

전기자동차 운용시 빈번히 발생되는 차량의 주정차기간에 축전지는 자기방전을 일으켜 용량의 손실이 발생하게 된다. 따라서 전기자동차의 잔존용량을 정확히 측정하기 위해서는 자기방전에 의한 용량손실을 고려하여야 한다. 이 논문에서는 전기자동차 운용시 빈번히 발생할 것으로 예상되는 주정차기간에 대해 포괄적으로 적용할 수 있는 Ni/MH Battery의 자기방전율을 나타내는 일반식을 전산모사 방법 중 하나인 실험계획법을 이용하여 구하였으며 이를 시험데이터와 비교하였다. 실험계획법을 위한 온도영역으로는 전기자동차가 운용되는 $-20\~30^{\circ}C$의 온도구간을 선정하였으며, 축전지의 방치시간으로는 자기방전이 상대적으로 크게 일어나며 빈번히 발생할 것으로 예상되는 영역인 1일$\~$15일 범위를 선택하였다. 이와 같은 방법으로 실험계획법에 의해 구해진 축전지 자기방전율에 대한 일반식의 타당성을 검증하기 위해 축전지에 대한 자기방전시험을 수행하여 비교하였으며, 그 결과 실험계획법으로 예측한 축전지의 자기방전율은 시험데이터와 우수한 일치를 나타내었다. When an EV is parked for a long period time, the battery capacity naturally decreases due to selfdischarge. Therefore, this effect must be considered for the accurate measurement of the state of charge of EV battery. Battery selfdischarge simulations using the design of experiments among computer simulation methods are compared with experimental data for Ni/MH batteries for electric vehicles. The motivation is to predict the selfdischarge rate of the battery for electric vehicle at all temperature conditions and standing time when electric vehicle could be operated. We developed a general equation representing the seudischarge rate of the electric vehicle battery using design of experiments, and the equation is determined by temperature and standing time of the battery. We selected Ni/MH battery, 12 V-95 Ah, for pure electric vehicle for this study. ID develop the equation using design of experiments we selected temperature range of $-20^{\circ}~30^{\circ}C$ and standing time of 1 day$\~15$ days. We conducted several selfdischarge tests of Ni/MH battery to verify the integrity of the equation. The results showed that the computation values were in good agreement with experimental data.

The Effect of Sub-division (Two or Three Sub-populations) of a Population on Genetic Gain and Genetic Diversity

Oikawa, T.,Matsui, H.,Sato, K. Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.6

Breeding efficiencies were compared among three population schemes: a single population, a population with two subpopulations and a population with three sub-populations. A simulation experiment of selection was carried out for 10 generations with 20 replications each by comparing average breeding values and inbreeding coefficients among the three population schemes. Phenotypes of three traits were generated with a model comprising 36 loci, each with additive genetic effects and residuals distributed normally. Among the three population schemes, the single population scheme was definitely superior to the other two with regards to selection response and inbreeding. The multiple sub-population scheme was, however, considered to be an alternative population scheme when the difference in economic weights of the traits was small among the sub-populations, assuming moderate inbreeding depression for traits and crossbreeding. The scheme with two sub-populations had a higher genetic value than that with three subpopulations; however, the genetic values of the schemes were comparable when maternal heterosis was taken into account. The choice of population schemes may depend on the cost-sharing policy between the breeding population and the commercial population rather than just the breeding efficiency.

可聽化를 利用한 Y 文藝會館 室內體育館의 音響 性能評價에 關한 硏究

윤재현(Yun Jae-Hyun),최둘(Choi Dool),김재수(Kim Jae-Soo) 대한건축학회 2008 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.28 No.1(계획계)

In case of Indoor Gymnasium, although its main purpose was sporting activity in the past, in recent days there are many cases that used as the multipurpose space where various public-performances are available such as resident's leisure activity, lecture and assembly activity, drama and concert. Accordingly, in order to maximum utilize the function of such Indoor Gymnasium, it is simultaneously required the Acoustic Performance with regard to the Definition of Voice and Music. However, in case of the gymnastic facility, since it has been designed as the higher ceiling-height for the sake of its characteristics, it forms a focus of tone and also the sound is concentrating to the specific part, and due to its large volume and the finishing material which has a strong reflexibility, and as the vibration of sound is too loud, it becomes to generate the acoustic defect such as many reverberations. On such viewpoint, based on the improvement device for the optimized architectural acoustic design presented by the preceded study, this Study has attempted to inquire into the Acoustic Satisfaction-Degree and its Response about the subject space, by conducting an Auralizational Experiment where possible to experience directly the Sound Field from the planning stage to its completion. As result of the investigation, at "After Improvement" comparing with "Before Improvement", the purpose of the sports facility together with its function as a multipurpose space with possibility of various public performances have been evaluated as suitable. It is considering that such material would be utilized as the fundamental material at the planning and designing stage of the similar sports facility hereafter, and it could be utilized as the useful material for the reduction effect of construction cost and enables us to improve the Acoustic Performance.