• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.63.1-63
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• 2002

In this work a new design approach of nonlinear control is presented based on a extended observer for the estimation and compensation on a dynamics system and the estimates are compared to the effects from neual nets. Simulation's results show that this method tells a good alternative to the standard ways.

• Korean System Dynamics Review
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• v.5 no.2
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• pp.175-197
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• 2004

The research studies the classic beer game simulation model from a new perspective. It does so by providing each agent with two ordering policies, and creating a set of rules that allow an agent to change its policy. Such a change is triggered based on an agent's confidence in their own performance, and on the relative confidence of their nearest neighbour. The overall effect is that policy diffusion can occur, where, under certain circumstances, an agent will mimic the behaviour of its neighbour, if it believes that its neighbour is performing better. The motivation behind this research is to provide an experimental base upon which the decision making strategies of business agent can be studied.

• Korean System Dynamics Review
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• v.5 no.2
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• pp.199-216
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• 2004

The present study is aimed at developing the optimal instruments for dispelling the uncertainty factors during the formulation of strategies for corporate development. The objective is the creation of a complete model of strategic analysis, which encompasses both the environment (internal and external) and the management rational component. This model -built on the analysis of three corporate cases - is concretized by a simulation for testing the strategy by the means of software which enables the users to cope with a dynamic and complex corporate environment. The research questions regard the development of a complete strategic analysis, which covers the entire decision-making process; the concrete assessment of the business strategy on the basis of quantitative data: the identification and enhancement of the critical variables of business administration, in such a complex and dynamic reality as the corporate environment.

• International Journal of Quality Innovation
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• v.8 no.2
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• pp.115-131
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• 2007

The vehicle development process (VDP) is iterative in nature with numerous interactions and information flows between design groups and between development phases. The VDP has been changed from a sequential-functional development to a concurrent-team based approach. Concurrent execution of design activities may reduce the development lead-time, but it increases the managerial complexity in the VDP. A system dynamics model was developed to understand the transient behavior of parallel, overlap, and sequential processes in the VDP and to determine the optimal level of overlapping considering the development lead-time and total number of reworks. The simulation results showed that different execution processes should be used, depending upon the intensity of reworks.

• Journal of KSNVE
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• v.8 no.1
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• pp.203-211
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• 1998

In order to find out relationship between hit probability and gun firing of a moving tank, a turret and flexible gun system model has been developed using a recursive flexible multibody dynamics. For a firing simulation model, nodal coordinates for a finite element model of a flexible gun have been employed to include transverse loads to the gun tube due to moving bullet and ballistic pressure. Modal coordinates are also used to represent the motion induced gun vibration before a firing occurs. An efficient switching technique from modal equations to nodal equation has been introduced for an entire gun firing simulation with a rotating turret.

• International Journal of Precision Engineering and Manufacturing
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• v.5 no.4
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• pp.28-35
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• 2004

Stimulated by novel phenomena observed in molecular aggregates, recent developments in engineering fields of microscopic scales are creating tremendous opportunities for future nanotechnology-based applications. Investigation in the field involves sub-nanosecond or sub-micrometer interactions between extremely small systems, but researches, to date in these physical extremes have been quite limited. Here, we shed light on some of nanoscale phenomena using molecular dynamics simulation: visualization of various phenomena of nanoscales and exploration of size-dependent mechanical properties.

• Korean System Dynamics Review
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• v.14 no.4
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• pp.37-62
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• 2013

The purpose of this paper is to find out some clues about effectiveness and implementing timing of the control measures against Foot-and-Mouth Disease (FMD) in Korea. To do that, the case of FMD, which broke out during November 2010 in Korea, is examined and constructed as a system dynamics simulation model. The implications of simulation result are as follows. First of all, it is most effective measure to prevent the movement of vehicle from infected farmhouse to other noninfected farmhouses, which are located far away, in the early stage of FMD diffusion. Secondly, earlier vaccination can be adopted as a reliable means to control the epidemic when FMD spreads widely. Finally, reducing the time to vaccinate the whole noninfected livestock is a little help to restrain the additional infections of FMD.

• Journal of Korean Institute of Industrial Engineers
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• v.40 no.2
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• pp.195-204
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• 2014

The transition from fossil to renewable energy is inevitable due to fossil depletion. So, Renewable energy is very important for energy security and economic growth although it's R&D is long-term and high risky project. We propose new valuation method which combined system dynamics and compound real option method for long-term and high risk projects such as renewable energy. This method can show dynamic valuation results for the complex causal interaction and be easy for Monte-Carlo simulation to estimate volatility. And it can reflect the value of flexible decision for uncertainty. We applied the empirical analysis for Korea's photovoltaic industry by using this method. As results by empirical analysis, photovoltaic's R&D has high valuation using this method compared by traditional valuation methods such as DCF.

• Korean System Dynamics Review
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• v.10 no.3
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• pp.105-124
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• 2009

The situation of the global food markets has been being rapidly restructured and entering on a new phase by new dynamic and driving forces. The factors such as economic growth and income increase, high energy price, globalization, urbanization, and global climate change are transforming patterns of food consumption, production, and markets. The prices and markets of world food and energy are getting increasingly linked each other. Food and fuel are the global dilemma issues associated with the risk of diverting farmland or of consuming cereals for biofuel production in detriment of the cereals supply to the global food markets. An estimated 100 million tons of grain per year are being redirected from food to fuel. Therefore, the objectives of this study are as follows: Firstly, the study examines situations of the world food and energy resources, analyzes the trends of prices of the crude oil and biofuel, and formulates the food-energy links mechanism. Secondly, the study builds a simulation model, based on system dynamics approach, for not only analyzing the global cereals market and energy market but also forecasting the global production, consumption, and stock of those markets by 2030 in the future. The model of this study consists of four sectors, i.e., world population dynamics sector, global food market dynamics sector, global energy market dynamics sector, scenario sector of world economic growth and oil price.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.2
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• pp.211-216
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• 2003

The influence of braking force generated by one tire on vehicle dynamics was investigated by simulation and ground test. A 8 d. o. f vehicle model was developed for simulation. And a special device to apply brake pressure to individual wheel was built for vehicle test. As a result of corner braking test on straight driving, the dynamic responses such as yawrate, lateral acceleration and roll angle were produced in the vehicle, which were in a good agreement to the simulation results. This shows that comer braking used in VDC system can control vehicle dynamics to improve controllability and directional stability.