• Journal of Korean Association for Spatial Structures
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• v.7 no.3 s.25
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• pp.87-95
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• 2007

The recent completions of free-form spatial structures provide us a very attractive form. To realize such an extraordinary shape, it is absolutely necessary that the connector systems have to be investigated the characteristics of the systems and analyzed with a practicable method. In this context, this research consists of not only literature research but also numerical analysis with selected connector systems, which was adopted in real free-form spatial structures. For numerical analysis, especially, finite element analysis (FEA) is performed with a various test parameter using a commercial program ANSYS. Consequently, the general characteristics of node connectors the moment-rotation-curves are presented by considering a large deformation effect as well as a multi-linear material properties.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.785-788
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• 2004

In order for concrete as a basic material constituting reinforced concrete structure to meet the required performance, it is necessary to satisfy various requirements in concrete construction. Among them, form work has significant effects not only on the process of molding fresh concrete but also on the quality and performance of hardened concrete. Recently, the decrease and aging of form workers is becoming a great problem in the construction industry and, as a result, it is required to rationalize form works and reduce labor costs for employing form workers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.42-43
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• 2008

The numerous application of ceramic superconducting bulk such as magnetic levitation train flywheel energy, levitation transpormation, magnetic bulk magnet etc. To obtain YBaCuO materials in the form of large single crystals are necessary. A refreshment and uniform distributon of the superconducting particle in the sample. The enhancement of the critical density was ascribe to a fine dispersion of the superconducting particle.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.439-442
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• 1998

In this paper, organic thin film LED(light emitting diode) having ITO glass/Alq$_3$/Al structure using an Alq$_3$ was fabricated by the vacuum evaporation and the absorbance, wave length, I-V characteristics were investigated, Electroluminescence of green and wavelength of 510[nm] were observed in this device. We observed absorbance form 320[nm] to 430[nm] and knew unstability of Alq$_3$ material as light emitting device.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.477-480
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• 1998

Sol-gel processing, which started some decades back as a laboratory curiosity, has proved to be a powerful and versatile technique for the synthesis of materials. The utility of the sol-gel method for producing glass and ceramic materials in the form of powders, fibers, thin films and bulk shapes with high purity, functional microstructures and potentially high chemical homogeneity at relatively low temperature (compared to conventional processing) has been discussed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.31-32
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• 2022

Unlike conventional building materials, the living building material (LBM) cube is composed of sand, gelatin, and cyanobacteria without cement. The surface of the LBM cube absorbs CO2 from the atmosphere by photosynthesis and is deposited in the form of CaCO3. In addition, the crystals generated in this process strengthened the gelatin-sand structure to enhance the compressive strength.

• Coupled systems mechanics
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• v.8 no.4
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• pp.299-313
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• 2019

The paper represents computer modeling of the deformed state of physically nonlinear transversally isotropic bodies with hole. In order to describe the anisotropy of the mechanical properties of transversally-isotropic materials a structurally phenomenological model has been used. This model allows representing the initial material in the form of the coupled isotropic materials: the basic material (binder) considered from the positions of continuum mechanics and the fiber material oriented along the anisotropy direction of the original material. It is assumed that the fibers perceive only the axial tensile-compression forces and are deformed together with the base material. To solve the problems of the theory of plasticity, simplified theories of small elastoplastic deformation have been used for a transversely-isotropic body, developed by B.E. Pobedrya. A simplified theory allows applying the theory of small elastoplastic deformations to solve specific applied problems, since in this case the fibrous medium is replaced by an equivalent transversely isotropic medium with effective mechanical parameters. The essence of simplification is that with simple stretching of composite in direction of the transversal isotropy axis and in direction perpendicular to it, plastic deformations do not arise. As a result, the intensity of stresses and deformations both along the principal axis of the transversal isotropy and along the perpendicular plane of isotropy is determined separately. The representation of the fibrous composite in the form of a homogeneous anisotropic material with effective mechanical parameters allows for a sufficiently accurate calculation of stresses and strains. The calculation is carried out under different loading conditions, keeping in mind that both sizes characterizing the fibrous material fiber thickness and the gap between the fibers-are several orders smaller than the radius of the hole. Based on the simplified theory and the finite element method, a computer model of nonlinear deformation of fibrous composites is constructed. For carrying out computational experiments, a specialized software package was developed. The effect of hole configuration on the distribution of deformation and stress fields in the vicinity of concentrators was investigated.

• Journal of architectural history
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• v.12 no.4 s.36
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• pp.27-48
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• 2003

This paper aims to identify the meaning of architectural form of the East and the West. Ordinarily, we know the visual differences of architectural form between the two cultural families, and the technical reasons of such differences. However, the East and the West have their own views of architectural form that are derived from their own views of architecture, and again the views of architecture are rooted in their own views of the world. The paper maintains a comparative stance between the two cultures in analyzing the different concepts of architectural form, and employ the ideas of 'Form(形象)' and 'Energy-Form(氣形)' as a kind of representative concept of the two views of architectural form. It is discussed that the idea of Form pursued the realization of ultimate substance which is less materialistic but more ideal., while, the idea of Energy-Form pursued the realization of oneness and health through mutual interaction between man, architecture and nature. Architectural form in the West has been the purposeful expression of human ideal, while in the East, it was an expediential device for better energy condition. It seems important to understand such differences of the meaning of architectural form between the East and the West, since, in present time, we tend to think that the Western conception of architectural form is the only possible one. But it is not generally known that the Western conception of form has very particular background reason of its own which is unique to Western culture, and on the other hand, the nature of East Asian conception of architectural form is generally unknown.

• Korean Journal of Computational Design and Engineering
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• v.11 no.4
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• pp.235-245
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• 2006

This paper proposes a CSG-based representation scheme for heterogeneous objects including multi-material objects and Functionally Graded Materials (FGMs). In particular, this scheme focuses on the construction of complicated heterogeneous objects guaranteeing desired material continuities at all the interfaces. In order to create various types of heterogeneous primitives, we first describe methods for specifying material composition functions such as geometry-independent, geometry-dependent functions. Constructive Material Composition (CMC) and corresponding heterogeneous Boolean Operators (e.g. material union, difference, intersection. and partition) are then proposed to illustrate how material continuities are dealt with. Finally, we describe the model hierarchy and data structure for computer representation. Even though the proposed scheme alone is sufficient for modeling all sorts of heterogeneous objects, the proposed scheme adopts a hybrid representation between CSG and decomposition. That is because hybrid representation can avoid the unnecessary growth of binary trees.

• Journal of the Korean Society of Costume
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• v.61 no.5
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• pp.123-138
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• 2011

This study examined how Chipogwan[緇布冠] with such a long history has been changed in China and Korea. With regard to the name, material, use and form of Chipogwan, the results of this study is summarized as follows. Chipogwan was mentioned continuously in ancient books of ceremonies and literature from the Tang dynasty [唐代], but from the Song dynasty [宋代] new name Chigwan [緇冠: a black hat] appeared besides Chipogwan. The two names were transmitted to Joseon dynasty [朝鮮] and used together until the mid Joseon dynasty, but from the 18th-19th centuries, Chipogwan was adopted according to ancient ceremonies and this name has been used continuously until today. The change of the name reflects the change of the material. Ancient Chipogwan was made of hemp [布] but when the term Chigwan appeared in the Song dynasty it was made of paper and Sa [紗: a 2-end simple gauze]. As other materials were added to hemp, po (布) was omitted from Chipogwan. As to the use of Chipogwan, it was a coronet used in purification ceremonies [齋冠] in ancient times. Then, it was used as Chogagwan [初加冠: a first hat putting on] in coming-of-age ceremonies [冠禮] from Zhou dynasty (周). During the Song and Joseon dynasty, Chipogwan was used in coming-of-age ceremonies as well as in daily life. As to the form, Chipogwan in ancient books of rites and the Song dynasty was a small coronet covering the topknot. In the Joseon dynasty, the form of Song dynasty was followed until the mid period, and then after the mid $18^{th}$ century, another form was proposed according ancient books of rites and an independent form of ceremonial coronet appeared that covered the entire head rather than covering only the topknot.