제품, 공정, 설비 정보 표현 방법을 개선한공정 중심 시뮬레이션 모델링 방법

백선중,오대균,이동건,이필립,유철호,우종훈,정용국 해양환경안전학회 2017 海洋環境安全學會誌 Vol.23 No.4

A process-centric simulation modeling method has been proposed to define a shipbuilding simulation model. Existing modeling methods have limitations for expressing various production information for a shipyard. The advanced process-centric modeling method proposed in this paper offers an improvement, effectively representing production information and constraints for a shipyard. To achieve this, a method and diagram components to define a process-centric simulation model in detail have been suggested. The modeling method can assign priorities when multiple products and facilities are assigned to the process. And layer concept was applied to express simulation model with hierarchical structure. To verify the effectiveness of the modeling method, comparative analysis has been performed and the actual shipbuilding process has been modeled using the proposed method. When a single facility was used for various purposes, we found that the proposed method was more advantageous than existing methods. As a result, it was possible to express constraints and flows that were difficult to identify with existing process-centric simulation modeling methods, and the methods were improved for use in shipyard production planning verification simulations. 본 연구에서는 기존에 제안되었던 공정 중심 모델링 방법을 개선하여 조선소의 다양한 생산 정보와 제약조건을 효과적으로 표현할 수 있도록 개선된 공정 중심 시뮬레이션 모델링 방법을 제안하였다. 그리고 이를 이용하여 시뮬레이션 모델을 구축할 수 있도록 다이어그램 구성 요소와 모델링 방법을 상세히 기술하였다. 이 모델링 방법에서는 복수의 제품과 설비가 공정에 투입되었을 때 우선순위를 지정할 수 있으며, 계층 구조를 가진 시뮬레이션 모델을 표현할 수 있도록 레이어 개념이 적용되어 있다. 그리고 조선소 생산 계획 정보를 바탕으로 절단 공정부터 대조립 블록 조립 공정까지를 본 논문에서 제안하는 방법으로 모델링하다. 이를 통하여 본 논문에서 제안하는 방법이 단일 설비가 여러 용도로 사용되는 경우에 기존의 모델링 방법에 비하여 유리한 것을 확인하였다. 결과적으로, 개선된 공정 중심 시뮬레이션 모델링 방법은 기존의 공정 중심 시뮬레이션 모델링 방법에서 표현하기 힘들었던 제약 조건과 흐름을 효과적으로 표현할 수 있으며, 계층 구조를 가진 조선소 생산 계획 검증 시뮬레이션 모델을 체계적으로 구축하는데 활용할 수 있다.

Simulation Research on a New Spot-First-Aid of Foreign Body Asphyxia in the Hypopharynx

Lanzhen Chen 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.6

Airway suffocation is a kind of unexpected emergency. The author's research group proposed a new spot-first-aid method of foreign body asphyxia in the hypopharynx, and compares it with traditional “Heimlich Maneuver” first aid method by simulation comparative study. This article mainly introduced the main contents and methods of the research, primarily on: the processing of CT Imaging data, including: Visual C++ program is used to realize the contour extraction algorithm processing based on CT images pre-processing, and restore the respiratory organs in asphyxia status in the processing of image morphology. Compare the two spot first aid methods by simulation. The Main research steps including: establishing simulated equivalent circuit simulation to compare two different spot first aid methods influence on the change of respiratory airway pressure and the animals steps of the experiments.

공공보건을 고려한 시뮬레이션 연계기반 속도관리전략 평가기법 개발

주신혜,오철 대한교통학회 2016 대한교통학회지 Vol.34 No.6

Recent interests in both vehicle emissions and public health have facilitated the development of more eco-friendly transportation systems. This study proposed an integrated simulation approach for evaluating the effectiveness of speed management strategies from the various perspectives including safety, operational efficiency, and environmental compatability. Those simulation methods include driving simulation, traffic flow simulation, emissions simulation, and air dispersion simulation. An essence of the proposed simulation framework is to create the systematic connection of each simulation method toward the evaluation of effectiveness of speed management strategies. As an example, chicane and speed hump in residential area were evaluated by the proposed method. It is expected that the proposed simulation-based approach would be effectively used for the decision-making process in selecting better alternatives considering both safety and public health. 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.

Simulation Optimization with Statistical Selection Method

김주미 한국경영과학회 2007 Management Science and Financial Engineering Vol.13 No.1

I propose new combined randomized methods for global optimization problems. These methods are based on the Nested Partitions (NP) method, a useful method for simulation optimization which guarantees global optimal solution but has several shortcomings. To overcome these shortcomings I hired various statistical selection methods and combined with NP method. I first explain the NP method and statistical selection method. And after that I present a detail description of proposed new combined methods and show the results of an application. As well as, I show how these com-bined methods can be considered in case of computing budget limit problem.

Simulation Research of Interference Magnetic Field Compensation Method on the Underwater Vehicle

Zhao Ta,Chenyu Wei,Zhouzhi Jian,Chengde Fu 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.4

It is one of the most difficult issues for underwater vehicle to accurately compensate the interference magnetic field elements in automatic navigation.The theory of geomagnetic navigation on underwater magnetic vehicle is complicated and the development of interference magnetic field compensation system is difficult, so in order to reserch the compensation method easily and effectively,it is a important way for using the finite element software on the computer to complete the modeling and simulation. In this paper, the space distribution characteristics of magnetic field around the vehicle are analyzed and the vector compensation mathematical model of interference magnetic field is established.At last, the feasibility of compensation method is testified by an united simulation system composed of Comsol Multiphysics and Matlab which is developed using the secondary development technology of software. The results show that the united simulation system can be convenient to complete the modeling and simulation of compensation method, not only accomplishing a magnetic field characteristic analysis and numerical calculation function, but also the simulation precision of compensation results is very high.

Efficient and Robust Inverse Simulation Techniques Using Pseudo-Spectral Integrator with Applications to Rotorcraft Aggressive Maneuver Analyses

김창주,이도현,허성욱 한국항공우주학회 2019 International Journal of Aeronautical and Space Sc Vol.20 No.3

This paper intends to propose new inverse simulation techniques to cope with the numerical stability and accuracy problems frequently encountered with the integration inverse simulation methods widely used today. To achieve this, the pseudo-spectral method is adopted as a time integrator of the aircraft motion equations. In addition, the quasi-Newton and fixed-point iterative methods are applied to solve the resultant nonlinear algebraic equations in an efficient manner. These algorithms are integrated into a moving horizon framework to guarantee fast numerical convergence. The proposed methods are applied to the analyses of rotorcraft aggressive maneuvers such as popup, pirouette, and depart/abort mission-task-elements defined in the rotorcraft handling qualities requirements, ADS-33E-PRF. Numerical properties of the proposed methods are thoroughly investigated to clarify the effect of the numbers of quadrature nodes and time-horizon segments, and the level of maneuver aggressiveness on the robustness and efficiency of the analyses. Numerical efficiency and robustness of the present method are identified using specially designed performance measures such as the number of iterations to obtain a converged solution, functional residuals at the final solutions, and the variation of the adaptive relaxation factor. The results show that the present approach can provide extremely fast solutions of the inverse simulation problems and presents strong robustness to the level of maneuver aggressiveness, long-term simulation, and solution control parameters. Therefore, it is worthwhile to use the present techniques as one of the inverse simulation methods.

빌딩 시뮬레이션 툴의 민감도 분석과 비매개변수적 몬테카를로 방법

김영진(Kim Young-Jin),박철수(Park Cheol-Soo) 한국건축친환경설비학회 2011 한국건축친환경설비학회 학술발표대회 논문집 Vol.2011 No.10

Building simulation tools have widely become available for prediction and assessment of the dynamic energy performance. However, the building simulation tools in which many assumptions and simplifications are inherited in uncertainty. Recently, a stochastic method using Monte-Carlo technique has been tried to deal with the aforementioned issues. This paper addresses applicability of non-parametric Monte-Carlo method in building simulation. For this study, a range of fifty unknown parameters were selected. A screening method is applied to analyze the order of priorities regarding input and output variables. Based on sensitivity analysis of the unknown parameters, the authors compare parametric Monte-Carlo methods (gamma, exponential, lognormal, normal, weibull, and ravleigh distribution) with nonparametric Monte-Carlo method (kernel density function) according to each uncertainty propagation (Simple Random Sampling, LHS [Latin Hypercube Sampling], and Quasi-Random Sampling). In the results, a nonparametric Monte-Carlo method reflected probability characteristics of the data relatively well compared to the parametric method.

몬테카를로 빌딩 시뮬레이션의 샘플링 방법과 모집단 추정

김영진(Kim, Young-Jin),박철수(Park, Cheol-Soo),김인한(Kim, In-Han) 대한건축학회 2012 대한건축학회논문집 Vol.28 No.6

Building simulation tools have widely become available for prediction and assessment of building energy performance. However, in process of building simulation, numerous assumptions, simplifications of reality and uncertain inputs are required. Recently, a stochastic approach is being recognized as an alterative to deal with the aforementioned issues. In order to properly apply one of the stochastic methods, a Monte-Carlo approach to building simulation, this paper addresses the following: investigating applicability of the Quasi-Random Sampling and of the non-parametric Monte-Carlo method. In this paper, a range of fifty unknown parameters were selected and identified based on the literature, and then a screening method was applied to identify dominant inputs on simulation outputs. To verify the applicability of the Quasi-Random Sampling, this paper used the two sample Kolmogorov-Smirmov test that compares the differences between two samples (Quasi-Random vs. Simple Random, Quasi-Random vs. LHS [Latin Hypercube Sampling]). The paper shows that the Quasi-Random Sampling method is surprisingly good enough. The authors compared the non-parametric Monte-Carlo method (Kernel Density Function) with several parametric Monte-Carlo methods (Gamma, Exponential, Lognormal, Normal, Weibull, and Rayleigh distribution). The paper shows that the non-parametric Monte-Carlo method can reflect probabilistic characteristics of the reality in a building relatively well in comparison with the parametric methods.

DSMC 및 IP 방법을 이용한 2차원 아음속 희박기체 유동 해석

최영재,권오준 한국전산유체공학회 2017 한국전산유체공학회지 Vol.22 No.4

In the present study, to investigate the characteristics of subsonic rarefied gas flows efficiently, the information preservation(IP) method was applied to the direct simulation Monte-Carlo(DSMC) method to reduce statistical scatters from the DSMC method for low speed rarefied gas flows. To find the effects of the IP method, the results of the IP method were compared to the results of the DSMC method for the same numbers of sampling. Before the comparison, it was necessary to verify the DSMC solver. The verification of the solver was conducted by simulations of the micro-channel flows by comparing to the other researchers’ DSMC results. The velocity profiles at the 2/3 section of the channel agreed well with the other researchers’ results. In addition, the normalized slip velocity distributions on the wall and the pressure distributions along the centerline also agreed well with the other researchers’ results. After the DSMC solvers were verified, two types of Couette flows were considered. One is the flows that have temperature differences between two plates, and the other is the flows that have moving plates. For the first Couette flows, the temperature of 373K was used for the upper plate, and of 173K for lower plate. For the second Couette flows, the upper plate is moving at 300m/s, and the temperature of 273K was used for both two plates. All simulations of Couette flows were conducted from near-continuum to free-molecular regimes. From both Couette flow simulations, it was found that the temperature jump and the velocity slip occurred on the plate surface. In addition, it was also shown that the temperature and the velocity differences between the plate and the gas became larger as the flow fields became more rarefied. Lastly, flow simulations around a NACA0012 airfoil were conducted to identify the effects of the IP method. The freestream Mach number of 0.8 was used, and the Knudsen number of 0.014 was considered. It was observed that more clear contours were obtained from the IP method than the DSMC method, since the statistical scatter error was reduced by the IP method. In addition, it was found that the velocity slip on the airfoil surface occurred due to the effects of the rarefied atmospheric environment.

An Estimation Method of Representative Humanoids for Digital Human Simulation

Kihyo Jung 대한인간공학회 2013 大韓人間工學會誌 Vol.32 No.3

Objective: The present study developed an estimation method of boundary zone representative humanoids(hereafter, EBZ method) using descriptive statistics on the design target population. Background: The boundary zone method(hereafter, BZ method) generates representative humanoids at a boundary zone that statistically accommodates a designated percent of the design target population; however, the BZ method has a practical limitation because it requires a large scale anthropometric database on the design target population. Method: The EBZ method developed in the present study consisted of 3 steps. In the first step, the boundary zone of accommodating a designated percent(e.g., 90%) is formed under the assumption of normal distributions for anthropometric sizes. In the second step, cases that fall within the boundary zone are estimated using descriptive statistics(mean, standard deviation, and covariance) on the design target population. In the last step, K-mean cluster analysis is conducted for the cases, and representative humanoids are selected from each of clusters. Results: Evaluation results showed that mean accommodation percent of the EBZ method was 90.9%(range: 90.8~91.1%) which is similar to the target percent(90%). In addition, standard deviation of accommodation percent for 100 repetitions was 0.1%. Lastly, the number of representative humanoids generated by the EBZ method(n = 20) was similar to the BZ method(n = 16). Conclusion: The EBZ method can generate representative humanoids which accommodate a designated percent of the design target population using descriptive statistics. Application: The EBZ method can be utilized in the generation of humanoids for ergonomic design and evaluation of products when the large scale anthropometric database on the design target population is not existed.