• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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• pp.169-175
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• 1997

Recently it is increased by degrees to produce complex and large lattice structures such as bridge, tower, crane, and space structures. In general, in order to analyse these structures we have used finite element method(FEM). In this method, however, it is necessary to use a large amount of computer memory and to take long computation time. For overcoming this problem, the Authors have developed the transfer dynamic stiffness coefficient method(TDSCM) which consists on the concept of the substructure synthesis method and transfer influence coefficient method. In this paper, the new free vibration analysis method for large type lattice structure is formulated by the TDSCM. And the results obtained by TDSCM are compared with those obtained by FEM, transfer matrix method and experiment. And it is confirmed for TDSCM to be the numerical high accuracy and high speed structure analysis method.

• 천문학회보
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• 제42권1호
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• pp.38.3-39
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• 2017

The N159 and N160 ionized regions in the Large Magellanic Cloud are an important extragalactic star-forming complex. The physical environments and the star formation stages are different in N159 and N160. We performed near-infrared polarimetry to those star forming regions with IRSF/SIRPOL 1.4-m telescope. Near-infrared polarization enabled us to trace the detailed structure of magnetic fields in star-forming regions. Through the polarimetric data of J, H, and Ks bands, we examined the magnetic field structures in the N159/N160 complex. In this presentation, we show complex distribution of the magnetic fields associated with dust and gas structures. We verify the local magnetic fields in each star-forming region, which appear to be related with local environments, such as interior and boundary of shell structure, star-forming HII regions, and boundaries between HII regions and dense dark clouds. We discuss the formation scenario of the N159/N160 complex suggested from the magnetic field structure.

• Wind and Structures
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• 제31권6호
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• pp.495-508
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• 2020

To investigate the structural behaviour of grouped tanks under wind loads, 2 problems need to be figured out, wind pressures on tank shells and critical loads of the shell under these pressure distribution patterns. Following the wind tunnel tests described in the companion paper, this paper firstly seeks to obtain wind loads on the external wall in a squarely-arranged cylindrical tank group by numerical simulation, considering various layouts. The outcomes demonstrate that the numerical method can provide similar results on wind pressures and better insights on grouping effects through extracted streamlines. Then, geometrically nonlinear analyses are performed using several selected potentially unfavourable wind pressure distributions. It is found that the critical load is controlled by limit point buckling when the tank is empty while excessive deformations when the tank is full. In particular, significant reductions of wind resistance are found on grouped full tanks compared to the isolated tank, considering both serviceability and ultimate limit state, which should receive special attention if the tank is expected to resist severe wind loads with the increase of liquid level.

• 한국공간구조학회논문집
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• 제10권2호
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• pp.95-103
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• 2010

본 논문에서는 비선형 강성방정식의 정확성 향상에 관해 연구한다. 대공간 구조물은 대경간을 가볍게 만들기 위해 두께비를 얇게 만들어야 하므로, 구조설계시 구조불안정 검토가 중요하다. 쉘형 구조물의 구조불안정은 초기 조건에 매우 민감하게 반응하며, 이는 대변형을 수반하는 비선형 문제에 귀착하게 된다. 따라서 구조불안정을 정확히 알아보기 위해 비선형 강성방정식의 정확성이 향상 되어야 한다. 본 연구에서는 스페이스 트러스를 해석 모델로 하며 접선 강성방정식과 비선형 강성방정식의 두 이론을 프로그램으로 작성하여 비선형 해석을 수행한다. 두 이론의 해석 결과를 비교 고찰하여 비선형 강성방정식의 정확성 및 수렴성 향상에 대해 검토 한다.

• 한국공간구조학회논문집
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• 제13권1호
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• pp.51-57
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• 2013

There can be diverse causes in the destruction of a large space structure by strong wind such as characteristics of construction materials and changes in internal and external wind pressure of the structure. To evaluate the wind pressure of roof against the large space structure, wind pressure experiment is performed. However, in this wind pressure experiment, peak internal pressure coefficient is set according to the opening of the roof in Korea wind code. In this article, it was tried to identify the change of internal pressure coefficient and the characteristics of wind pressure coefficient acting on the roof by two kinds of opening on the side of the structure with Hyperbolic Paraboloid Spatial Structures roof. When analyzing internal pressure coefficient according to roof shape, it was found that minimum (52%) and maximum (30%~80%) overestimation was made comparing to partial opening type proposed in the current wind load. It is judged that evaluation according to the opening rate of the structure should be made to evaluate the internal pressure coefficient according to load.

• 한국해양공학회지
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• 제5권2호
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• pp.16-30
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• 1991

A numerical procedure is described for predicting the dynamic responses of combined systems of floating breakwaters and huge offshore structures supported by a large numer of the floating bodies in waves. The hydrodynamic interactins among tatal floating bodies are taken into account in their exact form within the context of linear potential theory. Wave control effects are discussed with both hydrodynamic interactions and hydrodynamic-structure interaction effects. The method presented is applicalbe to combined systems of floating breakwaters and huge structures for ocean space utilization for which a number of practical uses are seen in the future.

• 한국해양공학회지
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• 제5권2호
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• pp.156-156
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• 1991

A numerical procedure is described for predicting the dynamic responses of combined systems of floating breakwaters and huge offshore structures supported by a large numer of the floating bodies in waves. The hydrodynamic interactins among tatal floating bodies are taken into account in their exact form within the context of linear potential theory. Wave control effects are discussed with both hydrodynamic interactions and hydrodynamic-structure interaction effects. The method presented is applicalbe to combined systems of floating breakwaters and huge structures for ocean space utilization for which a number of practical uses are seen in the future.

• Bulletin of the Korean Chemical Society
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• 제34권6호
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• pp.1835-1838
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• 2013

Polypyrrole-Gold (PPy/Au) segment nanowires are prepared using anodized aluminum oxide (AAO) templates and assembled into a curved superstructure. Since the shape of the obtained superstructures can be designed to be capsule-like with inner space for containing materials, and their openings and closures can be controlled with external stimuli, these structures can be useful for a large variety of applications. Inner space of capsule-like superstructures is an important factor for their applications, and the volume of the inner space can be assessed using the generalized equation suggested by J. K. Lim (Bull. Korean Chem. Soc. 33, 2699 (2012)). In this paper, we introduce a new approach to obtain correct and simplified equation without redundant assumption which was used to induce the previous equations, and recalculate the volume of the inner space in the capsule-like superstructure using a new equation.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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• 제6권1호
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• pp.38-43
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• 2003

This paper presents the results of a post-tensioning test and analysis of a pyramidal unit structure that is basic element for space structures. The behavior characteristics was analyzed and compared with the numerical analysis and the mechanism in test model was confirmed with geometrical analysis. The results of this paper show that the behaviors of space structures can be predicted in multi-directional Mero joint system. And the authors suggest the possibility of erection and shaping formation with comparatively small post-tensioning, and space structure with the mechanism should consider the nonlinear behavior due to large deformation.

• 한국공간구조학회논문집
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• 제1권2호
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• pp.101-110
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• 2001

A large floating structure is attracting great attention in recent years from the view of ocean space utilization. Its huge scale in the horizontal directions compared with the wavelength and relatively shallow depth make this type of floating structure flexible and its wave-induced motion be characterized by the elastic deformation. In this paper, a boundary integral equation method is proposed to predict the wave-induced dynamic response mat-like floating offshore structure. The structure is modeled as an elastic plate and its elastic deformation is expressed as a superposition of free-vibration modes in air. This makes it straightforward to expand the well-established boundary integral technique for rigid floating bodies to include the hydroelastic effects. In order to validate the theoretical analysis, we compare with the experimental result of reduced model test. Satisfactory agreement is found between theory and experiment.