• Korean Journal of Materials Research
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• v.4 no.7
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• pp.792-797
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• 1994

Force fields of syndiotactic isoregic PVF crystal have been extracted by optimizing a structure of 2,4,6-trifluoroheptane with ab initio Quantum mechanical method with 6-31G * * basis set, and applied to calculate the structure parameters and elastic constants of the material. The cell parameters turned out to be 5.205$\AA$, of a axis(chain axis), 8.457$\AA$, of b axis and 4.621$\AA$ of c axis. These parameters are in fair agreement with those of the atactic X-ray structure(5.04$\AA$, 8.57$\AA$, and 4.95$\AA$,respectively). The young's modulus of defect free syndiotactic PVF crystal was computed to be 267 GPa comparable to those of polyvinilidene fluoride(277-293 GPa) and polyethylene(264-337 GPa) crystals. Bulk modulus value obtained at optimum geometry is more than twice greater than that obtained at experimental geometry due to large difference of elastic compliance constant (especially Sgj element) at these two different geometries.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.917-920
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• 2005

This paper presents 3D graphics geometry processor for mobile applications. Geometry stage needs to cope with the large amount of computation. Geometry stage consists of transformation process and lighting process. To deal with computation in geometry stage, the vector processor that is based on pipeline chaining is proposed. The performance of proposed 3D graphics geometry processor is up to 4.3M vertex/sec at 100 MHz. Also, the designed processor is compliant with OpenGL ES that is widely used for standard API of embedded system. The proposed structure can be efficiently used in 3D graphics accelerator for mobile applications.

• Journal of the Korea Fashion and Costume Design Association
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• v.18 no.4
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• pp.63-75
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• 2016

This study examines the organic geometry in Isabel Toledo's collections in terms of the practicality of American sportswear tradition. This study conducts literary survey combined with case analysis of Toledo's works from her debut collection in 1985 to the recent ones. The organic geometry in Toledo's designs refers to the conversion of two-dimensional garment patterns into three-dimensional garment forms with the body as a medium, which is classified into the following categories in this study. First, 'fluidity' describes Toledo's highly fluid jersey dresses which maintain consistent structures by patchwork draping and suspension technique. Second, 'reductionist structure' illustrates that simple geometric shapes such as circles and squares disappear as soon as worn on the body. Third, 'origami construction' explains folding two-dimensional fabrics into three-dimensional forms, which causes the outlines of the body to appear abstract. Toledo's designs deliver the tradition of American sportswear through the organic geometry of garment construction. Toledo's works are authentic American in the aspects that they are functional and modern; they satisfy the practical needs, prioritize the movements of wearers, pursue multi-functions, and their ornamental elements are accompanied by the construction of garments. Isabel Toledo presents designs drawing on her unwavering aesthetics while continuously developing and experimenting creative ways of garment construction.

• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.103-106
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• 2001

• Journal of the Korean School Mathematics Society
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• v.6 no.2
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• pp.39-53
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• 2003

We study the dynamic geometry software suitable for the Internet Environment. First, we look into the necessity of dynamic geometry software and compare the functions and the features of commercial softwares, GSP, Cabri and Cinderella. Secondly, we introduce the process of development and the structure of the new software DRC(Digital Ruler and Compass) designed by authors and discuss the learning program with DRC and Internet, and view the upgrade of the software in the future.

• Journal of Biosystems Engineering
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• v.21 no.3
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• pp.343-356
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• 1996

The plot geometry of the paddy land is directly related to the performance of machines, especially those having a large size and high speed. The study was to investigate the optimum plot geometry from the standpoint of mechanization. A simulator, Field-Plot-Structure-Evaluation-System(FPSES) was developed for evaluation of the field performance of machines according to the plot geometry. The efficiency and capacity of different sizes of machinery used for rice farming functions were analyzed for a various combination of plot geometry, which could be used as reference for the land reclamation planning and mechanization programming. It is shown that the plot size of about two hectares having a length of 200m and width of loom may be optimum, considering the efficiency and capacity of large sized machinery available currently and in near future.

• Journal of the Korean Mathematical Society
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• v.33 no.4
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• pp.1139-1171
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• 1996

The purpose of our research is to understand geometric and topological aspects of real projective structures on surfaces. A real projective surface is a differentiable surface with an atlas of charts to $RP^2$ such that transition functions are restrictions of projective automorphisms of $RP^2$. Since such an atlas lifts projective geometry on $RP^2$ to the surface locally and consistently, one can study the global projective geometry of surfaces.

• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.409-411
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• 2014

Based on the first-principles computations, the nature of the microscopic geometry of the molecule-electrode contacts was addressed. The single-molecule junction was prepared by connecting hexanediothiolate (HDT) to Au(111) electrodes via one, two, and three Au adatoms having coordination number of one (CN1), two (CN2), and, three (CN3), respectively. The contact atomic structure and energy of the stretched Au-HDT-Au junction was observed. The analysis revealed that the contact geometry with lowest coordination number (CN1) is energetically more stable than CN2 and CN3.

• Kyungpook Mathematical Journal
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• v.50 no.4
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• pp.455-463
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• 2010

The differentiable manifold with f - structure were studied by many authors, for example: K. Yano [7], Ishihara [8], Das [4] among others but thus far we do not know the geometry of manifolds which are endowed with special polynomial $F_{a(j){\times}(j)$-structure satisfying $$\prod\limits_{j=1}^{k}\;[F^2+a(j)F+\lambda^2(j)I]\;=\;0$$ However, special quadratic structure manifold have been defined and studied by Sinha and Sharma [8]. The purpose of this paper is to study the geometry of differentiable manifolds equipped with such structures and define special polynomial structures for all values of j = 1, 2,$\ldots$,$K\;\in\;N$, and obtain integrability conditions of the distributions $\pi_m^j$ and ${\pi\limits^{\sim}}_m^j$.

• Structural Engineering and Mechanics
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• v.21 no.4
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• pp.451-468
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• 2005

Effective beam width models are commonly used to obtain the lateral stiffness of flat plate structures. In these models, an effective beam width is defined as the width when the flexural stiffness of the beam element equals the slab stiffness. In this present study, a method to obtain effective beam widths that considers the effects of connection geometry and slab cracking is analytically proposed. The rectangularity of the vertical member for the connection geometry and the combined effects of creep and shrinkage for the slab cracking are considered. The results from the proposed method are compared with experimental results from a test structure having nine slab-column connections.