• 수산해양기술연구
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• 제54권3호
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• pp.231-238
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• 2018

In this study, a ship motion control system design method is introduced for autonomous ships. Some related research results and technologies for autonomous ships have already been developed and applied to ships. For example, the Norwegian Maritime Authority and the Coastal Administration have signed an agreement that allows to test of autonomous ships in the defined area (port to port). Many countries and industries are pursuing to realize the autonomous vessel in the real world. In this paper, the authors try to develop related technology. As basic research, a ship model of the pilot vessel is developed and physical parameters are identified by experiment and simulations. Using the mathematical ship model, a control system is designed and control performance is evaluated by simulations.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.708-713
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• 2007

Finite element model updating has been performed using an optimization technique in the paper. The objective function consists of natural frequencies, modal assurance criterion values, and bandwidths of modes, which are obtained from finite element analysis and experiment. Young's modulus and damping coefficient of the material are selected as design variables whose values are modified to make the objective function as small as possible. To consider the loading effect of an accelerometer, its mass and moment of inertia are added to design variables. This model updating method has been applied to a cantilever beam, and experimental data are measured by modal test.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
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• pp.31-36
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• 2001

본 연구는 TMS 분석기의 성능 상태를 판정하기 위한 지능형 진단기 설계 방법을 제안하였다. NOn와 SOx를 계측하는 TH 분석기의 입, 출력 신호와 설비의 유지보수 경험을 이용하여 분석기의 동작 상태를 진단하는 Neuro-Fuzzy 진단 모델을 설계하는 방법을 제안하고, 실험 데이터로 시뮬레이션을 통해, 그 타당성을 입증하였다.

• Journal of Computational Design and Engineering
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• 제1권4호
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• pp.233-242
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• 2014

A magnetically levitated vehicle (Maglev) system is under commercialization as a new transportation system in Korea. The Maglev is operated by an unmanned automatic control system. Therefore, the plan of train operation should be carefully established and validated in advance. In general, when making a train operation plan, statistically predicted traffic data is used. However, a traffic wave often occurs in real train service, and demand-driven simulation technology is required to review a train operation plan and service quality considering traffic waves. We propose a method and model to simulate Maglev operation considering continuous demand changes. For this purpose, we employed a discrete event model that is suitable for modeling the behavior of railway passenger transportation. We modeled the system hierarchically using discrete event system specification (DEVS) formalism. In addition, through implementation and an experiment using the DEVSim++ simulation environment, we tested the feasibility of the proposed model. Our experimental results also verified that our demand-driven simulation technology can be used for a priori review of train operation plans and strategies.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1645-1650
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• 2003

A numerical and experimental study is made of thermal behavior of a hot chuck which is specially designed for flip-chip bonders. The hot chuck consists of radiant heat sources and a heated plate of very high conductivity, which is for achievement of high-speed heat-up. A simplified numerical model is developed to simulate unsteady thermal behavior of the heated plate. Parallel experimental work is also conducted for a prototype of the hot chuck. Based on the experimental data, the numerical model is tuned to improve the reliability and accuracy. Design analysis using the numerical model is conducted. The results of numerical computations illustrate that the radiant heater system adopted in this study satisfies the key design requirements for a high-performance hot chuck.

• 한국소음진동공학회논문집
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• 제16권7호
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• pp.720-728
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• 2006

A robust damage assessment technique is presented such that the location and severity of damage in structures can be identified using measured modal data. In order to identify the damage efficiently, the concept of design of experiment using orthogonal array is used for screening the main effects of each parameter which corresponds to possible damage location in FE model. Then, Taguchi method, which has been widely used for robust design in industry, is applied to parameter updating in analytical FE model. The numerical simulations of a truss structure show that damages in structure can be located from updated parameters.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.1204-1209
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• 1990

This paper offers the theory and method for regression analysis of the regression model with operational parameter variables based on the fundamentals of mathematical statistics. Regression coefficients are usually constants related to the problem of regression analysis. This paper considers that regression coefficients are not constants but the functions of some operational parameter variables. This is a kind of method of two-step fitting regression model. The second part of this paper considers the experimental step numbers as recursive variables, the recursive identification with unknown operational parameter variables, which includes two recursive variables, is deduced. Then the optimization and the recursive identification are combined to obtain the sequential experiment optimum design with operational parameter variables. This paper also offers a fast recursive algorithm for a large number of sequential experiments.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 동계학술발표대회 논문집
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• pp.45-50
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• 2005

The supply outdoor airflow rates are calculated and analyzed using a multizone network model in a high-rise residential apartment. The system parameters include parameters related to weather conditions, building conditions, operation conditions, and facility conditions. Simulations are conducted according to the method of design of experiments and analysis of variance is conducted to investigate the effects of parameters on ventilation rate. A correlation equation is derived to predict ventilation rates of the building depending on the various parameters.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 추계종합학술대회
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• pp.386-392
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• 2001

본 연구는 TMS 분석기의 성능 상태를 판정하기 위한 지능형 진단기 설계 방법을 제안하였다. NOx와 SOx를 계측하는 TMS분석기의 입ㆍ출력 신호와 설비의 유지보수 경험을 이용하여 분석기의 동작 상태를 진단하는 Nero-fuzzy 진단 모델을 설계하는 방법을 제안하고, 실험 데이터로 시뮬레이션을 통해, 그 타당성을 입증하였다.

• 제어로봇시스템학회논문지
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• 제8권11호
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• pp.916-921
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• 2002

We presents a new method of constructing an equivalent T-S fuzzy model by using the sum of products of linearly independent scalar functions from nonlinear dynamics. This method exactly expresses nonlinear systems and automatically determines the number of rules. We design a stabilizing controller f3r ul inverted pendulum system by using the concep of parallel distributed compensation (PDC) and linear matrix inequalities (LMIs) based on the proposed T-S fuzzy modeling method. We show effectiveness of a systematically designed fuzzy controller based on the proposed T-S fuzzy modeling method through the simulation and experiment of an inverted pendulum system.