• Biomedical Science Letters
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• v.6 no.4
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• pp.237-244
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• 2000

It has been reported that plasma membrane activity of the spermatozoa may be susceptible to be influenced by extracellular osmolality and such membranous changes involve infracellular molecular changes, special regard to the structure of membranous lipids, and the accompanying ion-channel of which are closely related with their fluidity of $Ca^{2+}$ and HCO$^{-}_{3}$. It is of common recognition that a certain kind of sterol acceptor player an important to induce lipid fluctuation of the sperm plasma membrane which have been influenced by BSA administration and came in effect to outflow of cholesterol from the spermatozoa and resulted in changes of ionic fluidity to facilitate adenylyl cyclase, and to induce protein tyrosine phosphorylation by increase of cAMP and activation of PKA. Thus it seems likely that an augmentation of the acrosomal reaction is closely related with protein tyrosine phosphorylation. The following experimental results were obtained in the present study; Under the high osmolality conditions, the spermatozoa motility declined significantly and the structural change of the plasma membrane diminished to confirm that the response degrees to the osmolality depended upon the water transfer volume through the plasma membrane and the changes of cellular volume. Those experimental results suggest that a physiological parameter such as low temperature condition played an important role for presentation of spermatozoa and that inducement of spermatozoa activation for reinforcement of protein tyrosine phosphorylation. On the other hand, it seemed likely that the BSA administration as one of sterol accepters might represent a key role also under the high osmolality condition and their result also suggests that osmolality change, special regard to high osmolality condition may play an important role also in the processes of signal transmission.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.10
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• pp.1754-1762
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• 2001

본 연구의 목적은 적합성과 기능성이 고려된 체형별 남성 상의 원형 패턴을 개발하는데 있다. 피험자는 인체계측자료와 측면체형 사진에 의해 선정하고, 체형은 굴신체형, 표준체형, 반신체형으로 분류하였다. 체형별 실험 원형 패턴의 평가를 위하여 기존원형을 선정하였으며, 연구 결과는 다음과 같다; 1. 착의평가 결과 표준체형은 대부분의 항목에서 적합하였으나, 굴신체형과 반신체형에서는 많은 차이가 있었다. 이러한 차이는 앞길이와 등길이 뿐만 아니라 여유량과 윗 가슴둘레에 서 나타난다. 앞품과 뒤품은 외관에 의해 많은 영향을 받으며, 증가된 옆품은 앞품과 뒤품의 부족분을 보충하는 역할을 하였다. 따라서 실험패턴은 기존패턴보다 각 체형에 더욱 적합하며, 체형 적합성과 동작기능성이 고려된 의복 제작을 위한 패턴설계는 인체의 구조와 동작연구에 의해 가능하였다. 2. 기본원형 패턴 설계를 위한 필요치수는 목뒤높이, 등길이, 앞길이, 윗 가슴둘레, 앞품과 뒤품이며, 체형분류의 기준은 윗 가슴둘레, 앞품, 뒤품, 앞길이, 등길이이다. 이와 같은 결과를 근거로 가슴둘레 선은 [(B/2+B/10), 뒤진동깊이는 [(B/10+목뒤높이/10)]로 설정하고, 앞내림은 1.5cm로 하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.400-400
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• 2016

자연하천에서 다양한 목적으로 설치된 수공구조물을 볼 수 있으며 대표적으로 교량의 교각을 들 수 있다. 교각 주위에서 발생하는 국부세굴은 교량붕괴의 가장 큰 원인이므로 이에 대한 연구는 필수적이다. 수리실험 또는 수치모형을 이용하여 교각주변의 국부세굴에 관한 많은 연구들이 수행되었지만 세굴인자의 특성 및 메커니즘에 대한 연구는 여전히 부족하다. 본 연구에서는 LES(large-eddy simulation)에 유사이송 및 하상변동 모형과 결합하여 2개의 원형교각 주변의 흐름 및 세굴을 수치모의 하였다. LES와 유사이송 및 하상변동 모형의 결합은 난류의 영향을 직접 모형에 고려할 수 있기 때문에 교각 주변에서 발생하는 말굽형 와 구조와 같은 복잡한 흐름에 의한 영향이 반영된다. 계산영역은 흐름방향으로 10 m, 횡 방향으로 2.4 m로 하였고, 지름(D) 0.16 m를 가지는 원형교각을 유입부로부터 2.4 m 떨어진 위치에 배치하였다. 이때 두 개 교각사이의 각은 $0^{\circ}{\sim90^{\circ}$이고 원형교각 사이의 거리는 5D로 하였다. 수치모의에 사용된 조건은 이전의 수리실험(Khosronejad et al., 2012)을 참고하여 접근평균유속은 0.25 m/s, 수심은 0.15m를 사용하였다. 수치모의는 원형교각 주변의 최대세굴심이 평형상태에 이를 때 까지 수행하였다. 접근각도 변화에 따른 원형교각 주변의 세굴과정 및 특성을 분석하였으며 최대 세굴심 결과를 Hannah(1978)의 수리실험결과와 비교하였다.

• Korean Journal of Plant Tissue Culture
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• v.25 no.1
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• pp.69-74
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• 1998

The somatic embryos of Daucus carota L. cv. Hongshim developed in MS basal medium far 4 weeks had varied number of cotyledons. Palisade and spongy parenchyma of cotyledon were not clearly discriminated in all seedlings developed from the embryos. No independent existence of collateral vascular bundle was observed in all seedlings with various types of cotyledon ; instead, vascular bundles were either interconnected or partially connected with one another. Most of the cotyledonary bases on hypocotyl showed short cylinder structure which encircle plumule. The vascular tissues of cotyledonary bases and nodes of seedlings with jar-shaped or 1 cotyledon were connected in ring forms, showing the pattern of ectophloic shiphonostele, and similar ring form structure was also found in the vascular arrangement of 5 cotyledon seedlings. The vascular bundles of seedlings with 2, 3 and 4 cotyledons in many cases had independently arranged within the cotyledonary bases and nodes, showing the pattern of eustele. In hypocotyl, tetrarch or hexarch xylems prevailed in seedlings with jar-shaped cotyledon or 1 and 5 cotyledon; tetrarch xylems prevailed in 2 cotyledon seedlings; and triarch xylems prevailed in 3 cotyledon seedlings. In most of seedlings, cortex vascular bundles were dispensed in the region from cotyledonary node to hypocotyl, but double vascular bundles were also observed occasionally. In roots, diarch xylems were observed in most of seedlings with 2 cotyledons, triarch xylems in half of seedlings with 3 cotyledons, and diarch xylems in most of the remaining seedlings with the occasional occurrences of tetrarch xylems.

• Journal of the Korean Geotechnical Society
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• v.36 no.10
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• pp.5-19
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• 2020

With increasing demand for offshore structures, the demand for temporary structures to help the offshore construction work has increased. A cofferdam is a temporary barrier to stop the inflow of water in the construction site and allows working in the dry condition when the construction is done within the water. However, it is a major cause of construction delays and increased costs because additional works are required to block the water inflow. Recently, in order to overcome the limitations of the conventional cofferdam methods and to increase economic efficiency, a large-diameter steel cofferdam method has been proposed which can be installed quickly in the seabed by using the suction pressure. In this circular steel cofferdam method, the top side of the cofferdam including the top-lid is always exposed above the sea level in order to use it as a water barrier, unlike the conventional suction bucket foundation. After installation, the top-lid of the cofferdam is removed and the water filled inside the cofferdam is discharged to make the interior dry condition. In this study, the circular steel cofferdam with a 5 m inner diameter was fabricated and the installation tests were conducted at the Saemaguem test site. During the experiment, variation of suction pressure, leakage between connections, structure deformation, and inclination of the steel cofferdam were measured and post-analyzed. This study verified the new circular steel cofferdam method and confirmed that the suction installation method can be successfully used for various purposes on offshore structures.

• Parasites, Hosts and Diseases
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• v.31 no.4
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• pp.301-314
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• 1993

An electron microscopic study was performed to observe the ultrastructure of the tegument of U seoulensis. The outer surface of the tegument was covered with a tnlaminated plasma membrane. The electron-dense cytoplasmic layer was $2.5{\;}\mu\textrm{m}$ wide In the anterior portion and contained numerous vacuoles, mitochondriae and granular materials in its matrix. The basement layer was 330 nm wade or so, and Its numerous extensions protruded into the cytoplasmic layer. The sensory organ was composed of a small vesicle of $1.7{\;}{\times}{\;}1.1{\;}\mu\textrm{m}$ in dimensions, which possessed a cilium of $1.2{\;}{\times}{\;}0.19{\;}\mu\textrm{m}$ in size. The pharynx was composed of the epithelial layer of about $0.5{\;}\mu\textrm{m}$ wide, well developed muscle layer and basement layer. The tegument of the oral sucker was composed of a cytoplasmic layer of $0.4-0.5{\;}\mu\textrm{m}$ width, a narrow basement layer, a well developed muscle layer and tegumental cells. Some kinds of secretory granules that seemed to be originated from the cells of the oral sucker were observed In the parenchymal portions of the adjacent cells. The tribocytic organ consisted of numerous microvilli. The microvilli were 5 nm wide and heptalaminated. Two types of secretory granules originated from the gland cells of tribocytic organ were observed In the tegument and parenchyme. The tegumental cells were irregular in shape, and of which nuclei were multifarious.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.12
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• pp.2816-2822
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• 2014

In this paper, a wideband loop antenna for UWB applications is studied. The structure of the proposed wideband loop antenna is a circular loop antenna with appended circular sectors to obtain an ultra-wideband characteristic. The circular sectors are used instead of conventional triangular sectors to match with the 50 ohm feed line. Optimal design parameters are obtained by analyzing the effects of the gap between the circular sectors and the radius of the circular loop on the input reflection coefficient and gain characteristics. The optimized wideband loop antenna is fabricated on an FR4 substrate with a dimension of 41 mm by 41 mm. Experiment results show that the proposed antenna has a frequency band of 3.1-11.0 GHz for a VSWR < 2.25, which assures the operation in the UWB band. Measured gain ranges 1.3-5.3 dBi in the UWB band.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.3
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• pp.60-71
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• 2010

The purpose of this paper is to provide a unified examination of apparently quite different gardens in terms of Carl Jung's psychological concepts such as Archetypes, Individualization, and a natural tendency towards balance or wholeness. In Jung's psychological framework, Archetypes are innate, universal prototypes for ideas and function as the first original models upon which all other similar persons, objects or concepts are derived, copied or patterned. Jung proposes that Individualization be achieved through a natural tendency towards balance, especially the balance between the conscious and the unconscious. This paper deals with three gardens, each of which represents a distinct cultural region: Bu-Yong Ji(芙蓉池) at the Changdeok Palace(Oriental), the Patio of the Lions at the Alhambra(Islamic), and the Fountain of Apollo at the Versailles Palace(Western). It is argued that all of three have in common a natural tendency towards balance and symbolize mandala, the archetype of wholeness. Bu-Yong Ji is in the form of quadrangle which embodies Yin and Yang. In the Patio of the Lions, the basin at the center and the four channels, which symbolize the waterway of the Garden of Eden and the four rivers in Paradise respectively, are constructed in the form of a quadripartite composition. The overlapped circle and rectangular shaped pond of the Fountain of Apollo also represents mandala. Symbols representing the same archetype can vary from culture to culture. This explains the differences among the three gardens with respect to specific aspects of external forms. In other words, an archetypal image can give rise to various forms in different cultures, and thus quite different mediums of design or design details may be developed. In conclusion, the three gardens give us a good example as to how an archetypal image can be expressed in different ways from culture to culture and how seemingly different design details can be analyzed in a unified way.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.754-758
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• 2010

케이블 교량에서 발생하는 사장케이블의 진동현상에 대한 현상학적 특성을 명확히 이해해야, 사장케이블의 적합한 제진설계가 가능하다. 본 연구에서는 유체의 흐름과 구조물의 진동을 동적으로 연계하여 해석하기 위하여, ADINA의 CFD 및 Structure 코드를 동적으로 연계하는 FSI(Fluid Flow with Structure Interaction) 기법을 이용하였다. 바람으로 인해 이중원형실린더의 풍상측과 풍하측 실린더에서는 와류가 방출되면서 외력이 작용하게 되며, 이러한 공기력은 풍하측 실린더의 고유진동 운동과 함께 와류진동현상을 유발한다. 본 연구에서는 풍하측 실린더의 와류진동 현상의 해석에 주안점을 두었다. 본 연구에서는 흐름의 레이놀즈수와 이중원형실린더에 대한 바람의 입사각을 변화시키며 풍하측 실린더에서 발생하는 와류진동의 크기를 분석하였다. 본 연구결과, 유입풍속 및 바람의 입사각에 따라 이중원형실린더에서 발생하는 일반적인 와류방출현상과 풍하측 실린더에 작용하는 공기력 및 변위양상을 예측할 수 있었다. 특히, 바람의 입사각이 $15^{\circ}$인 경우에는 풍하측 실린더에서 방출되는 와류로 인해 풍하측 실린더에는 비대칭의 공기력이 작용하며, 이는 풍하측 실린더가 2사분면에서 4사분면 방향으로 진동하는 원인이 되는 것으로 판단된다.

• Composites Research
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• v.22 no.6
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• pp.32-38
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• 2009

In this study, the energy absorption capabilities and failure modes of four different kinds of circular tubes made of carbon, Kevlar and carbon-Kevlar hybrid composites with epoxy resin have been evaluated. In order to achieve these goals, these tubes were fabricated with unidirectional prepregs and compressive tests were conducted for the tubes under 10mm/min loading speed. From the test results, carbon/epoxy tubes were collapsed by brittle fracturing mode and showed the best energy absorption capabilities, while Kevlar/epoxy tubes were crushed by local buckling mode and worst. The hybrid [$90_C/0_K$] tubes were failed in a local bucking mode and showed good post crushing integrity, whereas [$90_K/0_C$] tubes were failed in a lamina bending mode and bad post crushing integrity.