• Journal of the Korea Society for Simulation
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• v.22 no.3
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• pp.15-23
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• 2013

In general, simulation models are effectively used in the field of engineering design. The experiment with simulation models to obtain optimal design parameters, however, is a time-consuming task and requires a lot of resources. Hence, meta-models representing the relationships between input variables and performance measures are exploited to efficiently determine the value of design parameters. To construct a meta-model, a number of simulation executions with sample scenarios are required. The number and quality of sample scenarios determine not only the level of efficiency in constructing the meta-model but also accuracy of the model. Space-filling condition is regarded to be an important condition for the quality of scenarios. This paper proposes sample scenario generation methods based on space-filling measures such as maxmin, Audze-Eglais, and centered L2-discrepancy. The performance of these scenario generation methods are evaluated through experiments.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.322-325
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• 2005

TTX(Tilting Train eXpress) is being designed for improving the speed of conventional railway. The purpose of this study is to evaluate energy absorbing capacity and driver's survivability for a design candidate of the front end structure of TTX. A FE model with honeycomb block, under frame, and body frame is generated for crash simulation. Based on a level-crossing accident scenario, numerical simulation is performed using LS-DYNA. The results of crash analysis show that strength improvement of the current front end structure design candidate is needed to ensure driver safety.

• Journal of Korea Water Resources Association
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• v.47 no.2
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• pp.135-143
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• 2014

In this study, Chungju inflow was simulated for climate change considering the uncertainties of GCMs and a stochastic model. TFN (Transfer Function Noise) model and 4 different GCMs (CNRM, CSIRO, CONS, UKMO) based on IPCC AR4 A2 scenario were used. In order to evaluate uncertainty of TFN model, 100 cases of noises are applied to the TFN model. Thus, 400 cases of inflow results are simulated. Future inflows according to the GCMs show different rates of changes for the future 3 periods relative to the past 30-years reference period. As the results, the summer inflow shows increasing trend and the spring inflow shows decreasing trend based on AR4 A2 scenario.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.546-552
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• 2013

The future competitiveness of construction industry is dependent on K-12 students. However, unfavorable images of construction industry have negative influence on K-12 students' decision-making of their career. This negative image makes them not want to find out what actually happens in construction industry. Consequently, it is important to give K-12 students the opportunity to know what construction employees actually do in their job. Studies show that K-12 students who encounter the job early-on are more likely to choose it as their career. In this context, this paper proposes construction educational game in which it can serve as a medium for capturing K-12 students' interest in Construction Management (CM). Based on the literature reviews, challenges of construction educational game for K-12 students which are edutainment, hands-on experience and social interaction, are derived. To address these issues, conceptual model and scenario are designed. Based on designed scenario, prototype of Simulation based Construction Game in Virtual World (SCGVW) is developed in Second Life (SL) and applicability test to K-12 students are implemented. This paper concludes with a discussion of the lessons learned and the future development steps of the construction educational game for K-12 students.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.39-45
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• 2016

This study analyses the macroeconomic effects of the direct payment system (DPS) for environment-friendly agriculture in Korea. We utilized the applied general equilibrium model (AGE model) for the general agricultural sector as well as the environmentally-friendly agricultural sector. We considered several scenarios based on various direct payment amounts to measure and analyze economic impacts. Scenario 1 considers the current direct payment system. Scenario 2 examines an additional 5% increase from the direct payment amount in scenario 1. Scenario 3 reviews an increase of 10% in direct payment amount while Scenario 4 considers an additional increase of 15% compared with Scenario 1. Lastly, scenario 5 examines a 20% increase in direct payment amounts compared with scenario 1. In addition, the baseline considers conditions prior to the introduction of the direct payment system. The simulation analysis results show that capital formation, production volume, and labor productivity increased in the environment-friendly agricultural sector. In contrast, employment in the environment-friendly agricultural sector decreased. The price of environment-friendly agricultural products following the introduction of the DPS remain consistent with the price of environment-friendly agricultural product before introducing the DPS. This results from price elasticity of supply and demand are inelastic, and there is no change in the income of consumers during the analysis period. However, additional research is necessary for improvement of the model using complementary statistical data for the environmental-friendly agriculture sector.

• Journal of Biomedical Engineering Research
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• v.41 no.4
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• pp.154-164
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• 2020

Various simulator systems for surgery training have been developed and recently become more widely utilized with technology advancement and change in medical education adopting actively simulation-based training. The authors have developed tissue-instrument interaction modeling and graphical simulation algorithms for an arthroscopic surgery training simulator system. In this paper, we propose algorithms for basic surgical techniques, such as cutting, shaving, drilling, grasping, suturing and knot tying for rotator cuff surgery. The proposed method constructs a virtual 3-dimensional model from actual patient data and implements a real-time deformation of the surgical object model through interaction between ten types of arthroscopic surgical tools and a surgical object model. The implementation is based on the Simulation Open Framework Architecture (SOFA, Inria Foundation, France) and custom algorithms were implemented as pulg-in codes. Qualitative review of the developed results by physicians showed both feasibility and limitations of the system for actual use in surgery training.

• Journal of Korean Society of Rural Planning
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• v.14 no.2
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• pp.55-64
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• 2008

This study aims to analyze the sensitivity of WSM(weighted scenario method)-AHP method according to variation of nonlinear exponent for accessibility criteria, which are used to make urbanization potential maps with the optimal weighting value for multiple criteria in grid-based GIS technique. Besides this study tried to develop WSM-AHP2 which is simplified by using rank of the potential value for each scenario. The two methods were applied to the test area, Suwon city located south area of Seoul, with time series land-use maps of 1986 and 1996. The evaluation system of urbanization potential have 7 criteria including 6 accessibility criteria. The results of WSM-AHP2, the optimal weighting values and their corresponding potential maps, have almost similar with those of WSM-AHP. In the application of CA(cellular automata) model for expansion of urbanized area using the three potential maps by WSM-AHP, WSM-AHP2, and specialists's AHP evaluation, it also showed that the accuracy of simulation for actual urban area is the highest in the potential map of WSM-AHP, followed by WSM-AHP2 and specialists's AHP evaluation. From the results of this study, WSM-AHP and simplified WSM-AHP2 will be used to generate the optimal potential maps for land-use planning in urban fringe area.

• Journal of the Society of Naval Architects of Korea
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• v.61 no.4
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• pp.226-235
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• 2024

A method for quantifying the adaptability of ship maneuver scenarios for data-driven modeling of ship dynamics is developed based on the principal component analysis. A random maneuver scenario is suggested as a reference for ship dynamics, which can obtain the converged principal components of ship dynamics features by the Monte Carlo simulation. Principal components of conventional maneuver scenarios defined by the International Maritime Organization (IMO) are compared to that of the random maneuver. A conventional ship dynamics model for a container carrier vessel for four degrees of freedom dynamics is introduced to simulate the random and IMO maneuver scenarios. It is confirmed that the IMO tests follow the tendency of random maneuver scenario in terms of execution time and adaptability.

• Journal of Applied Reliability
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• v.15 no.2
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• pp.131-138
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• 2015

In modern warfare, the number of unmanned systems grow faster than any other weapon systems. Therefore, it is very important to predict and measure the combat effectiveness (CE) of unmanned weapon systems in battlefield for deciding defense budget to acquire those systems. In general, quantitative calculation of weapon effectiveness under complicated battlefield is difficult based on the future network centric warfare. Hence, many papers studied how to measure the combat effectiveness and tried to study a lot of related issues about it. However, there are few papers dealing with the relationship between the UGV (Unmanned Ground Vehicle)'s performance and CE in a ground battlefield. In this paper, we do the sensitivity analysis based on a given scenario in a small unit battle. In order to do that, we developed simulation model using AnyLogic and changed the input parameters such as detection and hitting probabilities. We also assess the simulation outputs according to the variation of input parameters. The MOE used in this simulation model output is survival ratio for Blue force. We hope that this paper will be useful to find which input variable is more effective to increase combat effectiveness in a small unit ground battlefield.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.434-444
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• 2013

In order to evaluate drought risk at upland according to climate change scenario (RCP8.5), we have carried out the simulation using agricultural water balance estimation model, called AFKAE0.5, at 66 weather station sites in 2020, 2046, 2050, 2084, and 2090. Total Drought Risk Index between the first month (f) and last month (l) (TDRI(f/l)) and maximum continuous drought risk index (MCDRI(f/l)) were defined as the index for analyzing pattern and strength of drought simulated by the model. Based on distribution maps of MCDRI (1/12), drought strength was predicted to be most severe in 2084 for all regions. Some regions showed severe risk of drought meaning over 20 days of MCDRI (1/12) in the other years, while MCDRI (1/12) in other regions did not reach 5 days. Even though maximum value of TDRI (1/12) in 2090 was greater than in 2050, more severe drought risk in 2050 than in 2090 was predicted based on MCDRI (4/6). It implies that drought risk should be assessed for each crop with its own growing season.