• The Journal of the Korea Contents Association
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• v.10 no.10
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• pp.172-179
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• 2010

The study on works motivated from interest in the nature of matters and inherent visual-perceptual structure in them aims at expressing formative continuity of the connections of three dimensions of simple geometrical shapes such as circles and lines, which are characteristics of shape of molecules. With such a purpose, this study examined the geometrical shapes in modern arts and structural connection and symbolism of molecule structure, and based on such considerations, it expressed successive formative beauty which comes from repetitive connection between units by creating stereogram of simple geometrical shapes of molecule structure. The types of works include a method of connecting the units of molecule models and molecules seen in electron microscope with lines as a parameter and connecting units directly, which are used to express body accessory and metallic sculptures. Consequently, it attempted formation occurring spatial composition of continuity of division and duplication through direct connection between units and circular continuity coming from connection of simple geometrical shapes of molecule images such as spheres and curves transformed into stereogram.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.4
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• pp.321-336
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• 2012

The shear behavior at the particle/surface interface such as rock joint can determine the mechanical behavior of whole structure. Therefore, a fundamental understanding of the mechanisms governing its behavior and accurately estimation of the interface strength is essential. In this paper, PFC, a numerical analysis program of discrete element method was used to investigate the effects of the surface roughness crushing on interface strength. The surface roughness was characterized by smooth, intermediate, and rough surface, respectively. Particle shape was classified into one ball model of circular shape and 3 ball model of triangular shape. The surface shape was modelled by wall model of non-crushing surface and ball model of crushing surface. The results showed that as the bonding strength of ball model decreases, lower interface strength is induced. After the surface roughness crushing was occurred, the interface strength tended to converge and higher bonding strength induced lower surface roughness crushing. Higher friction angle was induced in wall model and higher surface roughness induced the higher friction angle. From these findings, it is verified that the surface roughness and surface roughness crushing effect on the particle/surface interface shear behavior.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.6
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• pp.429-434
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• 2017

A molecular-continuum hybrid method was developed to simulate microscale and nanoscale fluids where continuum fluidics cannot be used to predict Couette flow. Molecular dynamics simulation is used near the solid surface where the flow cannot be predicted by continuum fluidics, and Navier-Stokes equations are used in the other regions. Numerical simulation of Couette flow was performed using the hybrid method to investigate the effect of solid-liquid interaction and surface roughness in a nanochannel. It was found that the solid-liquid interaction and surface roughness influence the boundary condition. When the surface energy is low, slippage occurs near the solid surface, and the magnitude of slippage decreases with increase in surface energy. When the surface energy is high, a locking boundary condition is formed. The roughness disturbs slippage near the solid surface and promotes the locking boundary condition.

• Journal of Korean Association for Spatial Structures
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• v.4 no.2 s.12
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• pp.63-71
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• 2004

The structural space is gradually wide and is wanting agreeable environment by the requirement and necessity of people who lives modem stage. The building coincides with such requirements and is the high rise building actual circumstances which is doing ultra-large. The confirmed report of the technology to organize great merit is becoming currently considerably important issue in constructing a building field. Thus, this paper examine closely for nonlinear unstable taking a picture uneasiness height of prosperity considering to initial imperfection by a numerical method with a space frame structure of discrete system in large space structure. Based on previous investigation method, this paper induce nodal stiffness matrix of solid truss elements considering geometrical nonlinear using finite element method. In this paper, three types of space structure considered; i) 1-free node space structure, ii) 2-free node space structure, iii) multi-free node space structure. It apply the above examples to a nonlinear program, next, grasp the characteristic of an unstable conduct and the result was a clearing low.

• Tunnel and Underground Space
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• v.16 no.5 s.64
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• pp.394-404
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• 2006

Dynamic behavior of rock structures depends largely on the dynamic characteristics of ground and input earthquake wave. For blocky rocks with intense discontinuities, the mechanical characteristics of blocks and structural and mechanical characteristics of discontinuities affect overall behavior. In this study, UDEC was adopted to evaluate the dynamic behavior of rocks with various structural characteristics. Obtained results were compared to those of $FLAC^{2D}$, a continuum analysis, and the validity of the method was examined for dynamic analysis of discontinuous rocks for earthquake. Analysis considering the discontinuity showed significant changes in structural shape by the influence of joint behavior, and the behavior by continuum analysis was overestimated.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.3
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• pp.215-221
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• 2004

Large machine and structure can not be normally treated as lumped parameter system. Such machine or structure must be broken down to individual beams or panels the motion of which must be analysed before an absorber system can be designed for each element. The absorber may be a lumped parameter system or a continuous system. One of the most common elements in a machine or structure is the cantilever, and in this paper is considered the design of a continuous parameter absorber to reduce the transverse vibrations of a beam. So this paper describes the method to obtain the accurate information about combined continuous beam system with DVA. This information is obtained from the combined system's receptance. and this paper shows the convenience and useful informations when design the dynamic vibration absorber with the combined system's receptance.

• Journal of Korean Society of Steel Construction
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• v.13 no.5
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• pp.587-597
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• 2001

The structural system that discreterized continuous shells is frequently used to make dome-type structures and these structures show the unstable phenomena by snap-through or bifurcation when a load level reaches certain critical value. The characteristic structural behaviour of a cable dome shows a strong nonlinearity and very sensitive according to the initial imperfection. In this study the shape finding problem by applying initial tension stress is investigated and using this the unstable phenomena of perfectly shaped and initially imperfected shape model by external forces are examined to grasp the unstable behavior of cable dome using the Geiger-type model.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1997.11a
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• pp.29-29
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• 1997

각광 받는 구조재료인 섬유강화 복합적층재에 대한 기계적 체결 거동은 본질적인 재료의 이방성에 의해서 파단강도가 파단 모우드와 매우 밀접한 관련을 갖는 것으로 알려져 있다. 따라서, 복합적층판 체결부의 정밀 구조 설계에서는 단순화에 따른 오차를 줄이고 정밀해에 의한 설계 및 해석이 요청된다. 특히, 층간응력 성분을 무시할 수 없는 두께를 갖는 복합적층 판의 기계적 체결부 해석이나 실제 구조물의 체결부에서 발생하는 굽힘이나 비틀림과 같은 하중 상태를 묘사하기 위해서도 정밀한 3차원 응력 해석은 필요하다. 하지만, 지금까지 기계적 체결부의 거동에 관한 연구는 층간응력 성분들을 어느정도 무시할 수 있는 얇은 평판에 대한 2차원 응력해석에 주로 국한되어 왔으며, 일부 수행된 체결부에 대한 3차원 응력 해석의 경우 여러 단점을 갖는 3차원 연속체 요소에 의한 유한요소 해석이 수행되었을 뿐이다.본 연구는 층간응력 성분들을 무시할 수 없는 두께를 갖는 복합적층판의 기계적 체결부 해석에 지금까지 사용되어온 3차원 연속체 요소에 의한 유한요소 방법이 갖는 단점들을 개선한 Layerwise 유한요소법을 이용하여 3차원 응력해석을 수행하였다. 특히, 선형상보성원리에 근거한 최적설계 기법을 응용하여, 기계적 체결시 핀과 적층판의 홀 사이에 발생하는 하중 전달 과정을 모사하고, 접촉력에 의한 홀 주위의 복잡하고 국부적인 응력 집중현상을 규명하여본다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.1
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• pp.148-155
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• 2010

The purpose of this study is to propose and evaluate the continuous joint constructed with MRS system which is utilized for floor system in the parking structures or commercial retail buildings. Four specimens were fabricated and tested to examine the structural performance of the continuous joint with different joint detailing. Structural test for the specimens was undertaken to simulate the actual stress condition of the negative moment resisting connection in the prestressed precast concrete parking structures with 8m span. Based on the experimental results, the MRS system could be designed as the ductile continuous joint governed by flexural behavior. Therefore the MRS system developed in this study would provide a superior joint behavior to conventional double-tee system when constructing monolithic joint composed of simply supported precast members.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.492-492
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• 2023

담수 생물종 시식역의 보전을 위해 하천 연결성 유지와 회복이 중요하지만, 하천관리에 있어 이를 고려하기 위한 기초자료나 관련 연구가 부족한 실정이다. 특히 인공장벽(artificial barrier) 영향에 대한 대부분의 연구는 어류이동에 초점을 두고 있거나, 그 공간적 범위를 제한하는 경향이 있다. 본 연구는 강과 하천을 연속체 개념으로 접근하여 생태학적 과정을 방해할 수 있는 모든 인위적 구조물을 인공장벽으로 간주하고, 댐과 저수지, 보와 같이 하천의 종적 연결성을 저해하는 3개 유형의 인공 구조물에 대해 공간자료를 구축하였다. 수치지형도로부터 하천중심선과 수리시설물(보), 호소 및 저수지 경계를 교차(intersection) 분석하여 유형별 구조물의 위치 정보를 추출하고, 기존 자료와의 비교·검증을 통해 자료의 신뢰성을 도모하였다. 인공장벽에 대한 공간자료는 구조물의 유형에 따라 국가하천과 지방하천, 소하천으로 구분하고 낙동강 대권역 내 총 195개 표준유역에 대해 밀도(barrier density)를 계산하였는데, 여기서의 밀도는 하천 연장에 대한 총 인공장벽의 수로 정의(barriers/km)된다. 본 연구의 주요 결과는 낙동강 유역 내 인공 장벽의 밀도와 유형, 하천별 공간분포에 대한 정량적 평가를 포함하고 있으며, 이를 기반으로 수생태계 연결성 회복을 위한 하천관리방안을 모색하고자 하였다. 분석 방법과 결과 등 자세한 내용은 발표를 통해 제시될 예정이다.