• 한국수산과학회지
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• 제21권4호
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• pp.195-205
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• 1988

Distribution of organic materials In the surface sediments was investigated in September 1983 in Chinhae Bay System. Bottom waters containing less than 1ml/l of dissolved oxygen were found in Masan Bay, and in part of Kohyonsong Bay and Wonmunpo Bay. Organic carbon content in the surface sediments of Masan Bay was about 25mg/g and it decreased with increasing distance from the inner Masan Bay. Mean organic carbon contents in Wonmunpo Bay and Kohyonsong Bay were 25.48 and 31.39mg/g, respectively, which are higher values than those in Masan Bay where large amount of domestic and industrial wastewaters art discharged into the surface water and extensive phytoplankton occurs almost year round. Mean organic nitrogen and pheophyton contents were also the highest in Kohyonsong Bay amont eight subareas. In Masan Bay, settling of organic materials on the surface sediments seemed to be not significant because of active tidal mixing and relatively small size of particulate materials. In Kohyonsong Bay and Wonmunpo Bay large fecal pellets produced in shellfish farms could be easily settled down on the sediment because of weak current regime. DO content in the bottom waters were low in the organic material rich areas, and that suggests biodegradation of organic materials in the surface sediments could be an important oxygen consuming process during the study period of September 1983.

• Fibers and Polymers
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• 제6권4호
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• pp.322-331
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• 2005

Graduated compression stockings (GCS) have been widely used for the prophylaxis and treatment of venous diseases. Their gradient pressure function largely related to their fabric structure and material properties. By combing fabric physical testing and wear trials, this study investigated the GCSs fabric structure and material properties at different locations along the stocking hoses, and quantitatively analyzed the effects of fabrics on skin pressure longitudinal and transverse distributions. We concluded that, Structural characteristics and material properties of stocking fabrics were not uniform along the hoses, but a gradual variation from ankle to thigh regions, which significantly influenced the corresponding skin pressure gradient distributions; Tensile (WT, EM) and shearing properties (G) generated most significant differences among ankle, knee and thigh regions along the stocking hose, which significantly influenced the skin pressure lognitudinal gradient distribution. More material indices generating significant gradual changes occurred in the fabric wale direction along stocking hose, meaning that materials properties in wale direction would exert more important impact on the skin pressure gradient performances. And, the greater tensibility and smoother surface of fabric in wale direction would contribute to put stocking on and off, and facilitate wearers' leg extension-flexion movements. The indices of WT and EM of stocking fabrics in series A have strong linear correlations with skin pressure lognitudinal distribution, which largely related to their better performances in gradual changes of material properties. Skin pressure applied by fabric with same material properties produced pronounced differences among four different directions around certain cross-sections of human leg, especially at the ankle region; and, the skin pressure magnitudes at ankle region were more easily influenced by the materials properties, which were considered to be largely related to the anatomic structure of human leg.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1994년도 춘계학술대회 논문집
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• pp.123-126
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• 1994

We discussed the thermal analysis for recording media with the variation of the laser pulse duration and the power and the temperature distribution for the optimized Te-based antireflection structure by using the computer calculations. If the radial diffusion of heat is negligible, we can calculate the maximum temperature at the spot center in recording layer by Simple Method, and the temperature profile considering the specific heat and the latent heat by Numerical Method. As a result, the effect of the heat sinking which acted as a loss for the hole formation can be minimized by introducing the pulse of the hole formation duration( $\tau$ ) shorter than the thermal time constant( $\tau$$\sub$D/) of dielectric layer. This requirments can be satisfied as using the dielectric thickness of the 7nd ART condition or the dielectric materials with low thermal diffusivity.

• Composites Research
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• 제30권6호
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• pp.343-349
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• 2017

A multifield variational formulation is developed for the finite element (FE) cross-sectional analysis of composite beams. The cross-sectional warping displacements and sectional stresses are considered to be the primary variables through the application of Reissner's partially mixed principle. The warping displacements are modeled using generic FE shape functions with nonlinear distribution over the beam section. A generalized Timoshenko level stiffness matrix is derived which incorporates the effects of elastic couplings, transverse shear, and Poisson's deformations. The accuracy of the present analysis is validated for the stiffness constants and elastostatic responses of composite box beams which correlate well with the experimental data and other state-of-the-art approaches.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.886-890
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• 1992

Recent investigations have been made on polymer Insulators of various types. The findings are related to experience on operational lines in foreign countries, design concepts, materials and tests about outdoor properties. Over last decade improvements have been occured in the design and construction techniques of polymer insulators. For transmission and distribution lines, it may be advantageous or even necessary to replace, the conventional porcelain or tempered glass insulators by lighter polymer insulators which have better mechanical properties.

• Acta Via Serica
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• 제7권2호
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• pp.89-108
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• 2022

Since the most ancient times, lapis lazuli had been used for luxury goods such as jewelry and seals, to embellish sculptures and weapons or the precious objects of tombs, such as the golden mask of Tutankhamon or the famous "Standard" of the royal cemetery of Ur. Much more recent seems to be its frequent use as a pigment in wall paintings or polychrome stucco. In this article, the question of the sources for this extremely rare mineral is briefly discussed and the places proposed by ancient scholars as deposits of the mineral are presented and examined. The information provided in the medieval Arabic and Persian scientific literature has been considered and compared with the data of our modern geological knowledge. A list of sites in Central Asia, the Middle East, and India with lapis lazuli occurrence on wall paintings illustrate its wide use in different artistic cultures and periods between the 2nd and 10th centuries C.E. These cultures are in fact different in ethnic and linguistic origin and in the religious, economic, and social sphere, but closely interconnected by common pan-regional artistic traditions in style, materials, and techniques employed. A case study investigated by the authors in the Friday Mosque of Iṣfahān gives an example of the use of lapis lazuli pigment in Islamic wall paintings and stuccoes.

• Earthquakes and Structures
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• 제27권2호
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• pp.97-111
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• 2024

In this paper, buckling conditions and retrofitting of cylindrical steel water storage tanks with different roof types and wall thicknesses were investigated by using finite element method. Four roof types of cylindrical steel tanks which are open-top, flat-closed, conical-closed and torispherical-closed and three wall thicknesses of 4, 6 and 8 mm were considered in FE modeling of cylindrical steel tanks. The roof shapes significantly affect load distribution on the tank shell under the seismic action. Composite FRP materials are widely used for winding thin-walled cylindrical steel structures. The retrofitting efficiency of cylindrical steel water tank is tested under the seismic loading with the externally bonded CFRP laminates. In retrofitting of cylindrical steel tank, the CFRP composite material coating method was used to improve of seismic performance of cylindrical steel tanks. ANSYS software was used to analyze the cylindrical steel tanks and maximum equivalent (von-Mises) and directional deformation were obtained. Equivalent (von-Mises) stresses significantly decreased due to the coating of the tank shell with FRP composite material. In thin-walled steel structures, excessive stress causes buckling and deformations. Therefore, retrofitting led to decrease in stress, reductions in directional and buckling deformation of the open-top, flat-closed, conical-closed and torispherical-closed tanks.

• 한국의류산업학회지
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• 제19권5호
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• pp.595-601
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• 2017

Advances in 3D garment simulation technology contribute greatly to consumers becoming more immersed in movies and games by realistically expressing the garments the characters in the movie or game are wearing. The fashion industry has reached a point where it needs to maximize efficiency in production and distribution to go beyond time and space in order to compete on the global market. The processes of design and product development in the fashion industry require countless hours of work and consume vast resources in terms of materials and energy to repeat sample production and assessment. Therefore, the design and product development tools and techniques must aim to reduce the sample making process. Therefore, this study aims to study a case for comparing the real garment sample making process to the virtual garment sample making process. In this study, we have analysed the differences between the real and virtual garment making processes by choosing designated patterns. As we can see from the study results, the real and virtual garments generally are made through similar processes in manufacturing, while the time consumed for each shows great variation. In real garment making, scissoring and sewing require the greatest number of work hours, whereas in virtual garment making, most of the time was spent in the simulation process.

• 한국의류학회지
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• 제35권3호
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• pp.325-335
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• 2011

This study analyzes the current educational curricula in the field of Clothing and Textiles in order to develop appropriate educational methods and courses. We reviewed the curricula offered by 58 Clothing and Textiles Departments at four-year universities in Korea. We analyzed the educational content of each curriculum by dividing all of the courses offered into eight categories. The analysis was based on the information posted on the universities' Internet websites, and the analysis was performed by using descriptive statistics. The results of this study are as follows: First, the educational courses of the Clothing and Textiles Departments are composed of, 36.2% design, 20.4% production, and 14.5% textile categories. In comparison with the results of a similar study conducted in 1999, emphases on the design, distribution, and marketing categories have increased, while the emphases on the production, apparel material, basic knowledge, and consumption science categories have decreased. Second, in the case of the apparel material category, basic knowledge of materials constituted 18.5%, the largest part of the category. The average number of units offered in the area of apparel materials by the 58 Departments was 17 units per year. The curricula were found to vary by regions of the country. The universities located in the Chungcheong region offer more textile material courses, but the universities in the Capital region offer fewer textile material courses than other regions. Departments that are affiliated with universities that emphasize Art and Design have more courses on basic knowledge, dyeing and finishing, and fabric design than other universities.

• 예술인문사회 융합 멀티미디어 논문지
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• 제7권2호
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• pp.437-444
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• 2017

기계구조물 부재의 단면에 구멍이나 또는 단면이 급격히 변화할 경우, 불연속 부분 주위에서 응력집중이 일어나며 파손이 발생하는 주요 원인이 된다. 그 이유는 부재에 작용하는 평균 응력보다 응력집중 부분에서 훨씬 큰 응력이 작용하기 때문이다. 본 논문에서는 시편의 부분 관통 구멍 주위에서 응력해석을 수행하여 구멍을 통과하는 선상의 주응력 차 값을 구하였다. 광탄성에서 최대주응력과 최소주응력의 차이는 등색프린지 차수와 재료의 프린지 상수를 곱한 값을 빛이 통과한 거리 즉, 시편의 두께로 나눈 값과 같다. 즉, 주응력의 차이는 광탄성 프린지 차수와 비례관계가 있으므로 유한요소해석에 의한 주응력 차이의 분포를 광탄성 실험결과에 비교할 수 있다. 유한요소 범용 소프트웨어인 ANSYS Workbench를 이용하였으며 유한요소법으로 해석된 값을 광탄성 실험으로부터 측정된 값과 비교한 결과 유사한 결과를 얻었다. 이로서 유한요소해석 결과는 실험결과와의 비교를 통해 타당성이 입증될 수 있었다. 또한 구멍깊이 변화에 따라 나타나는 응력분포를 사용하여 응력집중계수를 구하였다. 구멍깊이가 증가할수록 응력집중계수는 증가함을 나타냈다.