• The Journal of the Korea Contents Association
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• v.7 no.9
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• pp.18-25
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• 2007

A symbol is one of the images that represents individual elements, and it has the power of metaphoric delivery to its audiences. Symbols, in animation, allows the audience to perceive various descriptions as symbols, leading to variety of interpretation. And by providing psychologically deeper meaning to the audience, it enhances the symbolic value of the images. However, detailed study regarding symbol analysis leaves much to be desired. This paper is an semiological approach to the Czechoslovakia animator, Jiri Barta, and his symbolic images, with particular focus on the darkness symbols that appear in the Czech cultural characteristics.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.994-1000
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• 2004

대형시험장비가 설치되는 실험실의 계획에서 장비의 진동은 간과할 수 없는 고려사항이다. 따라서 시험장비를 지지하는 구조물과 기초의 설계시 시험장비의 운행 중 발생하는 공진을 피할 수 있는 구조적 체계의 진동특성에 대한 적절한 평가가 요구된다. 본 논문은 동적특성을 얻기 위해 바닥구조물의 FE 모델링에 관하여 기술하였다. 또한 진동저감을 위한 시험장비기초의 설계를 위해 tuning, 진동기준. 방진시스템을 검토하였다. 시험장비의 진동을 줄이는 최선의 방법은 low tuning 이였으며 이의 구현을 위해 방진스프링과 함께 단단한 콘크리트 블록위에 시험장비를 설치하였다. 총체적인 방진시스템의 구조적 진동특성은 이동성, 힘, 속도 스펙트라를 이용해 표현되었다. 전달과 지점이동 FRF의 비를 시뮬레이션을 통해 비교함으로서 바닥 슬래브의 진동전달 정도가 관찰되었다.

• Special Issue of the Society of Naval Architects of Korea
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• 2006.09a
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• pp.53-58
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• 2006

When the vibration troubles occur on the ship structure during the sea trial, the rectification work is very restricted because of in-situ limitation. Usually the finite element method is used to improve vibration characteristics of the structure, but it takes lots of time and effort in modeling the structure and adjusting the finite element model in order to consider appropriate boundary conditions of a complex ship structure. Therefore, experimental methods have been in general suggested to obtain proper countermeasures without time-consuming in modeling. In this paper, FRF(frequency response function) synthesis method is applied to estimate natural frequency of the modified ship structure, which is obtained from experimental and numerical methods.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1227-1228
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• 2015

본 연구에서는 기계적 충격 방식을 통한 주파수 상향방식을 이용하여 저주파 진동원으로부터 충분한 에너지를 수확할 수 있는 압전 구동 방식의 광대역 에너지 수확 소자를 제작하고 평가하였다. 유연한 외팔보의 진동으로 인한 기계적 충격은 압전 외팔보에 큰 두 번째 힘을 전달한다. 변형률이 커지고 주파수 상향방식을 사용한 결과로 출력 전력과 동작 주파수의 대역폭 또한 향상되었다. 제작된 에너지 수확소자의 질량체 비율은 ${\mu}=5.8$, 스토퍼의 거리는 d = 0.5 mm이며, 17 Hz의 주파수, $30k{\Omega}$의 최적 부하저항에서 $449{\mu}W$의 최대 피크 전력을 전달하였다. 또한 1 g로 가진하였을 때 11 Hz부터 28 Hz의 주파수 대역에서 동작이 가능하였고, 저주파수의 무작위 진동에서도 효율적으로 에너지 수확이 가능하다는 것을 입증하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.176-180
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• 2006

When the vibration troubles occur on the ship structure during the sea trial, the rectification work is very restricted because of in-situ limitation. Usually, the finite element method is used to improve vibration characteristics of the structure, but it takes lots of time and effort in modeling the structure and adjusting the finite element model in order to consider appropriate boundary conditions of a complex ship structure. Therefore, experimental methods have been in general suggested to obtain proper countermeasures without time-consuming in modeling. In this paper, FRE(frequency response function) synthesis method is applied to estimate natural frequency of the modified ship structure, which is obtained from experimental and numerical methods.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.9
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• pp.158-166
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• 1998

This paper presents a geometrical approach to the characteristic analysis of parallel mechanism with free joints intended for use as a planar task robot. Solution of the forward and inverse kinematic problems are described. Because the mechanism has only three degree-of-freedom output, constraint equations must be generated to describe the inter-relationship between actuated joints and free joints so as to describe the position and orientation of the moving platform. Once these constraints are incorporated into the kinematics model, a constrained Jacobian matrix is obtained. and it is used for the solution of the forward kinematic equations by Newton-Raphson technique. Another Jacobian matrix was derived to describe the interrelationship between actuated joints and moving platform. The stiffness, velocity transmission ratio, force transmission ratio and dexterity of the mechanism are then determined based on this another Jacobian matrix. The geometrical construction of the mechanism for the best performance was investigated using the characteristic analysis.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.01a
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• pp.385-387
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• 2023

본 논문에서는 물감의 유체성, 확산성, 흡착성, 흡수성 및 응고성과 같은 물감의 물리적 특성을 활용하여 사실적인 페인트 시뮬레이션할 수 있는 입자 기반 프레임워크를 제안한다. 현실에서는 물감이 흐르고, 확산하는 것뿐만 아니라 흡착하거나 시간에 지남에 따라 응고되는 현상을 쉽게 관찰할 수 있다. 본 논문에서는 이런 현상을 사실적으로 표현하기 위하여 SPH(Smoothed-particle hydrodynamics) 방식을 시뮬레이션 하였으며 Isotropic kernel이 아닌 Anisotropic kernel을 사용하여 확산 과정을 표현하는 방식을 소개한다. 우리의 방법은 Fick's law를 바탕으로 물질 전달 방식을 이용한 확산 과정을 표현하였으며, 시간이 지남에 따라 굳어가는 응고성, 그리고 Van der waals 힘을 기반으로 한 흡착 과정을 동시적으로 표현하여 사실적인 페인트를 구현하였다.

• Journal of the Korean Magnetics Society
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• v.2 no.1
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• pp.69-74
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• 1992

This paper describes the energy and speed characteristics of an induction coil-gun. The coil-gun has some merits that it can be easily installed and repeatedly used many times, it does not damage mechanically in the course of launch and the force exerted on the projectile is distributed uniformly. An equivalent circuit is employed for modeling the coil-gun. The circuit equations and equation of motion are then derived based on the equivalent circuit. These equations are solved numerically by using Runge-Kutta method. Finally the energy transfer ratios are obtained according to the variations of the resonant frequency of driving circuit and charging voltage of capacitors. The muzzle velocities of projectile are also obtained according to the variations of electrical conductivity and initial position of projectile, firing angle of driving circuit, charging voltage of capacitor and resistance of driving coil, respectively.

• Journal of the Korean Society of Safety
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• v.12 no.3
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• pp.178-184
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• 1997

Many mathematical techniques have been developed to determine the muscle forces and force distribution in biomechanical human model, because it is so important to understand internal forces resisting external loading. However, a three-dimensional mathematical model of wrist joint, which is essential to develop solid modeling and artificial wrist joint, has not been well developed. This study proposed to define three-dimensional mathematical model of distal radius and ulna of the human wrist and to develop a detailed two-dimensional finite element through comparisons to existing analytical models and experimental tests. This mathematical model were accurately recreated, allowing the internal tendon force as well as force transmission and distribution through the distal radios and ulna during dynamic loadings. The results found in this study indicate and support the findings of other investigator that cyclic loading condition results in higher compression force on distal radius and ulna and may be source of wrist disorder.

• Journal of the Korea Concrete Institute
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• v.16 no.3 s.81
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• pp.293-302
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• 2004

The transfer of prestress force in pretensioned prestressed concrete (PSC) members is of great concern because it affects directly the distribution of stress around the transfer zone. The design provision of current design code on the transfer length considers only the prestress intensity and the diameter of prestressing steels. However, other factors such as concrete compressive strength and concrete cover may affect greatly the transfer length. The purpose of the present paper is to explore the various factors that affect the transfer length in pretensioned PSC members. The bond stress-slip relation between prestressing steel and concrete was modeled first from experimental data and then this model was incorporated into the interface element. The interface element was used to perform the finite element analysis for pretensioned PSC members. The results indicate that the compressive strength and concrete cover are also very important parameters which affect the transfer length greatly. This means that the current design code, which considers only the effective prestress and diameter of prestressing steel, must be improved to take into account the other important variables of compressive strength and concrete cover. The present study allows more realistic analysis and design of pretensioned PSC members.