• Journal of the Korean Mathematical Society
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• v.47 no.5
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• pp.967-983
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• 2010

Let M be an n-dimensional complete simply connected Riemannian manifold with sectional curvature bounded above by a nonpositive constant $-{\kappa}^2$. Using the cone total curvature TC($\Gamma$) of a graph $\Gamma$ which was introduced by Gulliver and Yamada [8], we prove that the density at any point of a soap film-like surface $\Sigma$ spanning a graph $\Gamma\;\subset\;M$ is less than or equal to $\frac{1}{2\pi}\{TC(\Gamma)-{\kappa}^2Area(p{\times}\Gamma)\}$. From this density estimate we obtain the regularity theorems for soap film-like surfaces spanning graphs with small total curvature. In particular, when n = 3, this density estimate implies that if $TC(\Gamma)$ < $3.649{\pi}\;+\;{\kappa}^2\inf\limits_{p{\in}F}Area(p{\times}{\Gamma})$, then the only possible singularities of a piecewise smooth (M, 0, $\delta$)-minimizing set $\Sigma$ are the Y-singularity cone. In a manifold with sectional curvature bounded above by $b^2$ and diameter bounded by $\pi$/b, we obtain similar results for any soap film-like surfaces spanning a graph with the corresponding bound on cone total curvature.

• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.455-460
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• 2020

As computer hardware and computer graphics technologies have developed in recent years, one can find research on the creation of bubbles. However, it is not easy to find soap bubbles that are modeled and rendered using actual physical parameters. The bubbles are expressed in a variety of models and colors depending on which tool is used, which strength is used, and the conditions of the surrounding environment. Therefore, in this paper, we present synthetic methods to create virtual soap bubbles based on physical parameters derived from some straws such as the bubbles' diameter over time and the number of bubbles when blowing. On the top of that, we will show a model of a soap bubble that can be usable in a virtual reality contents and optimized with rendering parameters.

• Transactions of the Korean Society of Mechanical Engineers
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• v.1 no.2
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• pp.73-81
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• 1977

It is well known fact that there is a theoretical analogous relation ship in terms of differential equation between the stress distribution of a bar under pure torsional moment and the deflection of a membrane subjected to a uniform pressure. This relationship has been applied to the experimental determination of torsional stresses with troublesome and elaborative measuring procedure since Griffith's invention of the soap-film apparatus. In this paper, the soap-film was replaced by a highly polished steel plate and whole visualable deflectional contour-line-map was able to obtain by using Michelson Interferometer with Ne-He Gas Laser lignt source enabling to determine the stress distribution in the vicnity of the symmetrical inner-boundary in a section. Experimental results were satisfactory and the margin of error in the measurement was lower than 1%.

• Journal of the Korean Home Economics Association
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• v.35 no.2
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• pp.111-122
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• 1997

This thesis researched for the conservation of a suit of armor, one glove, one belt, and on knife case that General Jung, Gong-chung had been worn in the early 17 th centuries. The armor was Doojung-kab for the battle. It was made of two kinds of fabrics, one of them was silk satin's outer fabrics, the other was quilt4d cotton's lining. as the armor was made of silk and cotton, it was treated by dry solvents and dry soap. In the dry cleaning method, used solvents were n-hexane, cyclohexane, benzene, and n-decane. the volume ratio of dry soap was 120: 1. The reaction temperature was 30℃, and reaction time was 10 to 30 minutes per one turn. The glove, belt and knife case were made with leather. They were dipped on the polyethyleneglycol 150 saturated solution during 24hours at 50℃ and then dried naturally. They were washed by toluene to remove the untreated pp.E.G. on the surfaces. It was sterilized by two gases of methylenebromide and ethyleneoxied. For the conservation, it was packed thoroughly by ？ polyethylene film sheet without air.

• 보존과학연구
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• s.14
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• pp.94-108
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• 1993

The cultural properties of cloth are of animal orgin (silk), or of vegetable orgin(cotton, hemp, ramie). As clothes are of an orginic material, they were subjected to damage by chemical, phisigical or biological factors, viz, moulds insects, lights, humidity and temperature changes, etc. And these factors promote that clothes generally result from various types of deterioration. In 1992, We were performed the conservation treatments for total 9 pieces of cloth, such as 3 pieces of General PAK SHIN-RYONG(Important Folklore Material No.110) 3 pieces of Madam Jung(Important Folklore Material No.115) and 1 piece of King Se-jo(Important Folklore Material No.219). The procedure of the conservation treatment for clothes describe the following below. 1) The washing and dry-cleaning to remove the contaminated substances from cloth was used 0.2% stearyl potassium soap solution and the mixture solution compound of n-Hexane, C6H14. and n-Decane, C10H22. And after the washing and dry-cleaning, the dry of clothes was carried out in a warm condition. These steps were repeated in 2 times over for each cloth. 2) The repair of clothes was attached the similar textiles to stronger fabric linings by needlework.3) The reprodution was made for cloth of King Se-jo to equalize the type, color, quality and skill of materials. 4) After these above procedures, all clothes fumigated to prevent the biodeterioration by using the mixed gas of methyl bromide and ethylene oxide as insecticide and fungicide. 5) Finally for the purpose to keep in a safety long-term condition, the treated clothes sealed with Biaxially Oriented Polyvinylacohol Film(BO-PVA film) and Helium, purity 99.999%, filled up in sealed BO-PVA film bag.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.523-526
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• 2010

주어진 경계선에 대해 비누막이 생성하는 표면 모델링 및 시간에 따른 변형 시뮬레이션은 컴퓨터 그래픽스 응용 프로그램의 한 분야이다. 이 문제에 대한 이전의 연구들은 주로 기하적인 방법들을 이용하였기 때문에 물리적으로 정확한 변형을 다루지 못하였다. 본 연구에서는 정확한 기하를 바탕으로 물리기반 변형을 다루기 위해 이산미분기하학으로부터 비누막의 동적인 모델을 제안한다. 우선, 비누 성분의 물리적인 특성들을 고려한 에너지 모델을 정의하고, 이를 이산 영역에서 나타내기 위해 이산미분기하 및 이산화 기법들을 이용한다. 제안하는 모델은 평형 상태에서의 비누막 형상뿐만 아니라 외력에 대한 표면의 변형까지 정확하게 나타내며, 실시간 시뮬레이션이 가능하여 게임, 애니메이션 목적으로 활용될 수 있다.

• Journal of the Korean Society of Clothing and Textiles
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• v.10 no.3
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• pp.27-36
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• 1986

The purpose of this study was, to estimate the detergency of commercial detergent and to examine the interrelationship between detergency and detergent characteristics, detergent concentration, fiber characteristics, and Rolling-up phenomenon which is the major removal mechanism of oily soil. A mixture of oleic acid-olive oil was used as oily soil. The detergency was estimated by analysis of oleic acid on cotton ana polyester fabrics before and after washing by means of liquid scintillation counting. The Rolling-up of oily soil from PET film was observed and change of contact angle and removal time were measured. The results were as follows ; 1. In the case of soaps and powder synthetic detergents, the optimum concentrations we-re about $0.2\~0.3\%$. And detergencies of liquid synthetic detergents were considerably low, and the detergency was continually increased up with increasing concentration to $0.5\%$, which seemed to be caused by the lower pH than that of soap and powder synthetic deter-gent solutions. 2. As the effect of external or internal fiber structure; the detergency of cotton was lower than that of polyester. 3. In the observation of Rolling-up, the contact angle increased and the Rolling-up time became shorter with increasing detergent concentrations ($0.05\~0.5\%$). And it was confirmed that detergency was increased with Rolling-up effect. In addition, the study on the actual laundry condition was studied using the questionaire. From the results, about $76\%$ of households used the concentration of detergent roughly or excessively and housewives were highly concerned on the recommended dose, but grade of practice were very low.

• Journal of Korean Association for Spatial Structures
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• v.7 no.2 s.24
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• pp.115-124
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• 2007

The initial shape is arrived at by a self-formation process, which accomplishes a form in the natural world, or is determined analytically by considering the equilibrium of initial stress only. Therefore, the self-formation process, which accomplishes a form in the natural world is grasped and the types of modeling techniques available to find the shapes of soft structures are well investigated and classified. To establish a form-finding modeling techniques, the models of string, soap film, fabric, rubber, plaster, and etc. are used. These modeling techniques can be used as a method of understanding the characteristics of structures when the material of model shows similar characteristics. Generally, the model test confirms the structure based on numerical analysis, at the same time it is important preceding process to develop such a program. With the above process, the relationship between model test and numerical analysis becomes a feedback process. Therefore, in this study, two examples which have been accomplished from such a technique are investigated and considered according to modeling process.

• Cartoon and Animation Studies
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• s.51
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• pp.293-319
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• 2018

Thanks to the advancement of the related technologies and equipment, today's video contents like movies, animations and soap operas are rapidly expanding their expressible cinematic imagination area. In order to fulfill the elevated visual expectations of audiences and realize exciting storytelling and fantastic world, the fusion of different techniques is actively used, and the reality for visual effects and image synthesis is increasing more and more. Accordingly, recent VFX-oriented movies using CG have a much more complicated production process than before. Therefore, the importance of Pre-visualization, aka Pre-vis is becoming bigger in the planning process for sophisticated design. Pre-vis means that the advance visualization for stories or directing ideas in the planning process before starting production of movies or animations. 3D animated Pre-visualization realizing directors' abstract and ambiguous ideas in 3 dimensional environment in advance is, as a powerful means for visual storytelling, briskly used focusing on the VFX film industry on which the present CG is broadly used, and the role of Pre-vis throughout productions has increased compared to the past. The studies, however, on the role and utility of Pre-vis are not enough. Therefore, this study was conducted on the role of Pre-vis used for present VFX movie productions using the examples of 3D animated Pre-visualization production in which the researcher of this study participated. In this study, the role of the Pre-vis that is subdivided presently, is divided into and 3D animatics and their each role is analyzed with the example images. Through this, the characteristics that Pre-vis should have are clarified and the concept of the advantages and utility led by the use of Pre-vis in productions is strengthened. The goal of this study is to induce active uses of Pre-vis throughout productions after forming consensus about the various roles of Pre-vis and their utility.