• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1996년도 춘계학술대회논문집
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• pp.168-185
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• 1996

In this research, an investigation of the eye movement was performed when the objects perceived by the eye are three-dimensional objects, two dimensional images, and three dimensional image. This investigation was done by observing the EOG(Electro-oculogram) waves which were achived from experiments. The observed waves were categorized into several groups. Differences among the waves were analyzed for each object and image perceived by the eye. In order to obtain waves to be analyzed, two kinds of experiments were performed. In each experiments, the saccadic eye movement and the smooth pusuit eye movement was considered as an independent variable individually. Waves obtained from the experiments were categorized into 4 types(Wave1, Wave2, Wave3, Wave4) depending on their characteristics. Unlike from the other images, three dimensional image was revealed as a key factor for the active movement of the eye. Futhermore, a unique eye movement was observed in the case of three dimensional image where the focus of the eye was achived in three steps.

• 대한인간공학회지
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• 제16권1호
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• pp.1-13
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• 1997

In this research, and investigation of the eye movement was performend when the objects perceived by the eye are three-dimensional objects, two dimensional images, and trhee dimensional images. This investigation was done by observing the EQG(Electro- oculogram) waves which were obtained from experiments. The observed waves were categorized into several groups. Differences among the waves were analyzed for each object and image perceived by the eye. In order to obtain waves for analysis, two kinds of experiments were performen. In each experiment, the saccadic eye movement and the smooth pursuit eye movement were considered as an independent variables. Waves obtained from the experiments were categorized into 4 types (Wave-1, Wave-2, Wave-3, Wave-4) depending on their characteristics. Unlike the other images, three dimensional image was revealed as a key factor for the active movement of the eye. Futhermore, a unique eye movement was observed in the case of three dimensional images where the focus of the eye was achieved through three steps.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 추계학술대회 논문집
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• pp.198-203
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• 2003

Unsteady two-dimensional nonlinear waves which are generated by the numerical wavemaker of plunging type are numerically simulated using a finite difference method in rectangular grid system. Two-dimensional Navier-Stokes equations and the continuity equation are used for the computations. Irregular leg lengths and stars are employed near the boundaries of body and free surface to satisfy the boundary conditions. Marker-density function method is adopted for the simulation of wave breaking phenomena, and the computations are carried out with various wave amplitudes and two section shapes of wavemaker. The computation results are compared with other existing computational and experimental results, and the agreement between the experimental data and the computation results is good.

• 한국해양공학회지
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• 제10권3호
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• pp.62-73
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• 1996

Numerical simulation is made of the three-dimensional wave breaking motion about a part of a floating offshore structure containing a circular cylinder mounted vertically onto a lower hull in regular periodic gravity wave generated by a numerical wave maker. TUMMAC-VIII finite-difference method is newly developed for such a problem. By use of density-function technique the three-dimensional wave breaking motion is approximately implenented in the framework of rectangular grid system. A porosity technique is devised for the implementation of the no-slip bydy boundary conditions. The generation of breaking waves by the interaction of incident waves with the structure is well simulated and interesting features of breaking waves are revealed with containing degree of quantitative and qualitative accuracy.

• Journal of Ship and Ocean Technology
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• 제5권4호
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• pp.29-43
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• 2001

In this paper, free surface flows around an advancing two-dimensional rectangular cylinder piercing the free surface are studied using numerical and experimental methods. Especially, wave breaking phenomenon around the cylinder is treated in detail. A series of numerical simulations and experiments were performed for the purpose of comparison. For the numerical simulations, a finite difference method was adopted with a rectangular grid system, and the variation of the free surface was computed by the marker density method. The computational results are compared with the experiments. It is confirmed that the present numerical method is useful for the numerical simulation of nonlinear free surface waves around a piercing body.

• Journal of Ship and Ocean Technology
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• 제6권3호
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• pp.13-25
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• 2002

In this paper, the motion responses with hydrodynamic interaction effect between two off-shore floating structures in various heading waves are studied by using a linearized three-dimensional potential theory. Numerical calculations using three-dimensional pulsating source distribution techniques have been carried out for twelve coupled linear motion responses and relative motions of the barge and the ship in oblique waves. The computational results give a good correlation with the experimental results and also with other numerical results. As a result, the present computational tool can be used effectively to predict the motion responses of multiple offshore floating structures in waves.

• Journal of Ship and Ocean Technology
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• 제7권1호
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• pp.13-18
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• 2003

The control performances for active re-reflecting wave control suggested in the previous paper have been verified in cases of regular and irregular waves in a real two dimensional wave basin. For regular waves, the control performances are investigated in terms of reflection coefficients, expected amplitudes of propagating waves and wave absorbing capabilities after cessation of wave generation, compared with those of no-control cases. For irregular waves similar verification procedures were adopted. Though there are certain constraints due to the geometrical non-linearity of wave maker and certain nonlinear characteristics due to the near field and gravity waves these experiments show that the control logic could be useful in realizing re-reflecting wave control in conditions of real wave basin.

• 대한조선학회논문집
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• 제31권4호
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• pp.82-98
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• 1994

본 논문에서는 파중에서 조종운동을 하는 선박에 작용하는 유체력에 대한 수학적 모델을 확립하고, 이에 대한 수치해석을 수행하였다. 파중에서 운항하는 선박은 입사파의 주파수에 의존하는 고주파수 운동과 선박의 조종운동에 따른 저주파수 운동을 하게되므로, two time scale expansion 방법을 적용하여 속도포텐셜에 대한 선형경계치 문제를 정립하였으며, 선박의 조종운동에 미치는 파의 영향은 2차차수 저주파수 표류력만을 조종운동방정식에 포함시켜 고려하였다. 속도포텐셜에 대한 적분방정식의 해는 3차원 파넬방법을 사용하여 구하였으며, 선박에 작용하는 힘은 직접적분법을 사용하여 계산하였다.

• 한국해양공학회지
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• 제10권3호
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• pp.50-61
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• 1996

The breaking phenomenon of regular periodic waves generated by a numerical wave maker is simulated by finite-difference method which can cope with strong interface motions. The air and water flows are simultaneously solved in the time-marching solution procedure for the Navier-Stokes equation. A density-function technique is devised for the implemenation of the interface conditions. The accuracy is examined and applied to the simulation of two-dimensional breaking phenomena of periodic gravity waves.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2005년도 제25회 추계학술대회논문집
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• pp.136-140
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• 2005

일차원 ZND 데토네이션 구조 해석 모델의 연장선상에서 경사 충격파와 경사 데토네이션 파에 대하여 Rankine-Hugoniot 관계식과 반응속도를 연계한 이차원 경사 데토네이션 파의 구조해석 모델을 제시하였다. 이에 기반을 두어 삼중점, 횡단 충격파 및 셀 구조를 포함하는 경사 데토네이션 파의 비정상 상세 구조를 조사하기 위한 이차원 유체역학 해석을 수행하였다. 전산 유체 해석 결과는 경사 데토네이션 파의 상세구조에 대한 깊이 있는 이해를 제공하며, 해석 모델은 경사 데토네이션 파를 연소 메커니즘으로 이용하는 극초음속 추진기관의 통합 설계도구로 이용될 수 있을 것이다.