• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.389-394
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• 1997

Consider a tetrhedron is composed of six dihedral angles .phi.(i=1,2..., 6), and a vertex of a tetrahedron is also three dihedral angles. It will assume that a vertex A, for an example, is composed of there angles definded such as .alpha..betha. and .gamma. !. then there is a corresponding angle can be given as .phi1.,.phi2.,.phi3.. Here, in order to differentiate between a conventional triangle and dihedral angle, if a dihedral angle degined in this paper is symbolized as .phi..LAMBDA.,the value of cos.theta.of .phi./sab a/, in a trigonometric function rule,can be defined to tecos.phi..LAMBD/sab A/., and it is defined as a tetradedral cosine .phi. or simply called a tecos.phi.. Moreover, in a simillar method, the dihedral angle of tetrahedron .phi..LAMBDA. is given as : value of sin .theta. can defind a tetra-sin.phi..LAMBDA., and value of tan .theta. of .phi..LAMBDA. is a tetra-tan .phi..LAMBDA. By induction it can derive that a tetrahedral geometry on the basis of suggesting a geometric tetrahedron

• Fibers and Polymers
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• 제7권2호
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• pp.195-202
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• 2006

Tight-fitting clothing pattern reflecting the accurate information of the 3D body shape has been one of the challenges for garment industry, however, fitting problems still exist. The objectives of the paper is to develop a 2D pattern which fits tightly to the 3D human scan data for sports suits that need comfort and function for maximum performance. In this study, the user graphic interface application software for the semi-automatic garment pattern generation has been implemented using the triangle simplification scheme together with 2D projections of free-falling of 3D surface polygons keeping the original 3D surface area preservation. A typical application of the developed pattern to the functional body suits is presented and verification of the proposed method is also provided.

• EDISON SW 활용 경진대회 논문집
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• 제5회(2016년)
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• pp.262-267
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• 2016

In this paper, to design Human Powered Aircraft(HPAC) with high aspect ratio wing which behave with large displacement under lift distribution causing a failure itself, then steel wire has been designed to prevent its failure. unit load method is used to calculate reaction force on wire and Optimal Triangle(OPT) membrane is employed to analyze its main wing spar with large displacement. EDISON CSD solver, linear static analysis and co-rotational nonlinear static anaysis both using OPT membrane produce behaviors of beam for each case of wire location about main wing spar, and aerodynamic coefficient also, by using aerodynamic analysis tool.

• 한국농공학회지
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• 제18권4호
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• pp.4209-4217
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• 1976

The purpose of this thesis is to search for the determination method of pumping rates in the existing tube wells for irrigation. Pumping tests were carried out for the twelve test tube wells which were selected in the provinces of Kyounggi, Kangwon, Chungbuk and Chungnam. The depths, static water levels, pumping levels, drawdowns and yields of tube wells were measured in the pumping tests, and a centrifugal pump with 3 inches diameter, a 5 HP motor and a 90$^{\circ}$ V-notch were used in the pumping tests. The average coefficient of transmissibility calculated by Chow's and Jacob's methods is 0.0336 square meter per second, and the average pumping rate calculated by Thiem's, Smreker's, Brinkhaus' and Theis' formulae, is 919 cubic meter per day, Therefore, the ground water storage in the test areas is comparatively abundant. Correlation between pumping rates and depths of tube wells is not in existence. Also, correlation between pumping rates and the thickness of aquifer is not found in this experiment. This shows that the depths of some tube wells are deep and their thicknesses of aquifer are thick, but their ground water storages are poor, and that the depths of some tube wells are shallow and their thicknesses of aquifer are thin, but their ground water storages are abundant. It seems that the test tube wells are influenced by the peculiar characteristics that the ground water in the test areas is free ground water in alluvium layer closely related with surface water. As drawdown increases, pumping rate decreases, and as the coefficient of transmissibility increases, pumping rate also increases. Namely, there are negative correlation between pumping rate and drawdown, and positive correlation between pumping rate and the coefficient of transmissibility. Judging from the results of the pumping tests in these tests areas, the pumping rate calculated by the formula, {{{{ { Q}_{m } =Q { ( { { S}_{ m} } over { TRIANGLE S } )}^{ { 2} over {3 } } }}}} used traditionally, is likely to be higher than real pumping rates. The formula, {{{{ { Q}_{m } =Q { { H}^{ 2} } over { (2H- TRIANGLE S) TRIANGLE S} }}}} derived from Thiem's theory, is looked upon as the reasonable one to detemine pumping rates in the existing tube wells for irrigation.

• 대한조선학회논문집
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• 제38권2호
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• pp.62-70
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• 2001

선체 외판은 복잡한 3차원 곡면 형상이며 이의 제작을 위한 곡가공은 조선에 있어서 필수적인 공정이다. 곡가공 공정은 주된 1차곡 성형을 위한 프레스 공정과 2차 이상의 나머지 곡 성형을 위한 열간가공 공정으로 이루어진다. 특히 전체 작업량의 50% 이상을 점하는 열간가공 공정은 숙련된 기능공의 작업 경험에 전적으로 의존하고 있다. 이의 자동화를 위한 많은 연구가 있었으나 최근까지의 연구는 주로 선상가열에 한정되어 있으며 삼각가열에 대한 연구는 극히 미미한 실정이다. 본 연구는 향후 삼각가열에 대한 효율적인 변형해석 기법을 개발하기 위한 기초 연구로서 삼각가열에 의한 판의 변형특성을 명확히 하는데 그 주안점을 두었다. 우선, 실제 조선소에서 현장조건 그대로 일련의 선가열 및 삼각가열 실험을 수행하여 각각의 변형특성을 비교 분석하였으며 상변태온도 이상의 고온영역을 확인함으로써 그 변형특성을 합리적으로 해명하였다. 또한, 가열시편에 대한 물리시험을 통해 현재 조선소에서 행해지는 열간가공 방법이 선각재료의 성질 변화에 미치는 영향을 검토하였다.

• 한국항해학회지
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• 제12권3호
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• pp.23-37
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• 1988

This paper deals with the method of determining the drag of hull surface which has any quality of roughness. The method consists mainly of the theoretical point of view, then the theory enables the drag coefficient to be calculated at full scale. The hydrodynamical roughness function of hull surface ${\triangle}U_+$, affected by the hull roughness are considered as to two cases, smooth surface and rough surface case separately. The inadequacy of a single parameter to define hull roughness is discussed and thus an as additional texture parameter is proposed.

• East Asian mathematical journal
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• 제26권2호
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• pp.141-150
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• 2010

In this study, we study on the length of bisector of angle by the method using the area, the method using the vector and the method using the similarity, also the length of trisector of angle by the method using the sine law, the method using the area and the method using the second law of cosine in triangle, respectively. And we study on the length of trisector of angle with the length of bisector in angle. This study is expected to use the learning materials for the interesting construction and the problem solving using trigonometric functions.

• 복식
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• 제59권3호
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• pp.131-144
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• 2009

This study is about single-layered $Chog{\breve{a}}ri$ excavated from SongHyosang(宋效商, 1430-1490, SHS hereafter), SongHeeJong(宋喜從, the late 1500s, SHJ hereafter) tombs. There are 7 single-layered $Chog{\breve{a}}ris$ for men. We focus on comparison of their design and sowing method. 1. Design: Investigating collar, $Chog{\breve{a}}ris$ from SHS have MokpanGit and $Chog{\breve{a}}ris$ from SHJ have KalGit. KalGit has been seen from SHJ to 17th, 18th and 19th centuries. After the late 1500s, there is no MokpanGit single-laTered $Chog{\breve{a}}ri$ for men. Side panel under arm has various shapes(triangle, trapezoid, triangle+trapezoid) in 15th century. After the late 1500s, It changes into no side panel. Two $Chog{\breve{a}}ris$ with no side panel from SHJ reveals that the late 1500s is a period of transition. 2. Sewing method: First, researching lengthwise grainline of the fly, the left fly has lengthwise grainline outside In four, inside in three. The right fly has lengthwise grainline outside in just one, the others have lengthwise grainline inside. Compared with today's way, there is a great difference, but in those times there isn't an established rule. This is true of side panel under arm. The sewing method are backstitch, running stitch, and hemming. Researching the construction method of seam, in putting two selvages together, open seam and plain seam are used. In putting selvage and bias, bias and bias together, flat felled seam and french seam are used. This study shows that single-layered $Chog{\breve{a}}ri$ far men from 15C. to 16C. has changes of design such as collar(Git) and side panel undo. arm. But there is little change in sewing method.

• Journal of Korean Neurosurgical Society
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• 제29권6호
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• pp.794-799
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• 2000

Objectives : The purpose of our study was to compare findings of brain SPECT representing crossed cerebellar diaschisis(CCD) with brain MRI, to evaluate relation between CCD and location of lesions on MRI and to elucidate clinically apparent cerebellar sign in patients with CCD. Methods : The study population was 20 patients representing CCD on SPECT. Percentage differences(${\triangle}%$) of activity on each cerebellar hemisphere were obtained from ipsilateral and contralateral cerebellum[${\triangle}%cbll=(IL-CL)/IL{\times}100$] and from cerebrum [${\triangle}%cbr=(CL-IL)/CL{\times}100$]. From MR studies, the percentage differences of signal intensity were also calculated as the same method. We compared the degree of percentage differences with location of cerebral lesions and with clinical cerebellar signs of the patients. Results : Among those representing CCD, the parietal lesions were the most common. There was significant correlation of the percentage differences in cerebellum between SPECT($18.8{\pm}7.22$) and MRI($4.4{\pm}3.38$) (p<0.05) and in cerebrum between SPECT($28.7{\pm}15.35$) and MRI($42.8{\pm}10.94$) (p<0.05). Cerebellar signs were observed in 3 of the 20 patients. However, there was no statistically significance between degree of percentage differences of each cerebellar hemisphere on SPECT and clinical cerebellar sign(p>0.05). Conclusion : Using the percentage differences in the cerebellum, the CCD evaluation can be easily done. On MRI, the signal changes of cerebellum were not as definite as SPECT. Despite of our assumption, there was no significant correlation between clinical cerebellar signs and CCD on SPECT.

• 한국컴퓨터정보학회논문지
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• 제23권4호
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• pp.121-129
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• 2018

The purpose of this study is to provide a basic data of clothing development which can improve the satisfaction of the body shape by examining the subjective evaluation and type characteristics of the old-old women themselves. Q methodology was used for the study of subjectivity. The types of the body shape of the old-old women were analyzed as five types: bent body with protruding abdomen, backward bent body with slender legs, inverted triangle, swollen cylinder, triangle. The bent body with protruding abdomen had a bent back and waist. They were recognized that the bust and shoulders were sagging and abdomen was protruding. The backward bent body with slender legs was the smallest of the five types with a BMI index and shoulders and bust were sagging. And knee and waist were bent and legs were thin. The inverted triangular shape showed the highest BMI index among the 5 types, indicating that it is obese. They thought that the upper body was developed and the lower body and legs were slender. The swollen cylinder shape was analyzed to be the smallest and the most fat body. The triangle shape had developed lower body and bent back and waist. It is considered that a design consideration is needed to cover the disadvantages of the body shape in consideration of not only wearing feeling but also aesthetic part when making clothes. By making ergonomic garments considering the characteristics of body shape, it can be expected to change the body shape due to the wearing of clothing that is not suitable for body shape and the effect on physical health in a positive direction.