Power-MOSFET를 이용한 가변 주파수 싸이크로콘버터에 관한 연구

서영수,김영춘,김성균 明知大學校 産業技術硏究所 1992 産業技術硏究所論文集 Vol.11 No.-

Ordinary cycloconverters have been used for low speed apparatus due to the fact the their practical output frequency is limited to the range of from 1/3 to 2/3 of input frequency. With power converters are applied to various kinds of production line, there are increasing in load that have need of consecutive operation from low speed to high speed. thus, interests in power converter which is able to consecutive drive are increase. For forced commutated cycloconverter (FCC) which does not require a DC link and can be used with most AC loads type of variable frequency and be able to AC-AC direct conversion, we consider cycloconverter system that can control from 10[Hz] to 500 (Hz) Power-MOSFET. And this paper also shows the reduced effect of harmonics and the effectiveness of the proposed system, which are thoughly tested and proved through the experiments in the output frequency range of from 5[Hz] to 1.5[kHz].

궤도 차량의 기동성능 예측 프로그램 개발

서정길,김종수,김용태,이경식,한성현 한국공작기계학회 2004 한국공작기계학회 춘계학술대회논문집 Vol.2004 No.-

In this paper, we developed a Windows XP version off-line programming system which can simulate a track vehicle model in 3D graphics space. The track vehicle was adopted as an objective model. The interface between users and the off-line program system in the Windows XP's graphic user interface environment was also studied. The developing language is Microsoft Visual C++. Graphic libraries, OpenGL, by Silicon Graphics, Inc. were utilized for 3D Graphics.

반복적인 실신 및 실신전환자의 기립경사 검사시 뇌혈류 변화

조수진,김준수,이광호,정진상,송희정,이상철,서정돈,이원로 대한신경과학회 1999 대한신경과학회지 Vol.17 No.3

장방형 밀폐공간내의 유체유동 및 전열특성에 관한 수치해석

서이수,유신오,전성모 東亞大學校 大學院 1997 大學院論文集 Vol.22 No.-

In this paper were investigated the numerical study of fluid flow in which the difference analysis connected the natural convection and mixed convection within enclosed condition. The cell boundaries arrangement for these calculations, uniformally divided as 44×44 when heated the bottom to muliply the length and height, and was in proportion 4 : 1 to the length and height when heated the left side to muliply 88×11. According to the repeat calculation of time division were obtained the temperature distribution, the velocity distribution, the isotherms distribution, & streamlines distribution in which the natural convection was altered Pr=0.71, Gr=10?. Gr=5×10?, Gr=10? and the mixed convection was changed as Pr=0.71, Re=100, Re=1000. For the numerical study on the heat transfer and fluid flow, the following consequence have calculated in proportion 4 : 1 to the length and hieght of rectangular enclosure with the number of Pr=0.71, the number of Re=100, 1000, the number of Gr=10?, 5×10?, 10?.

감귤과피 물 균질액으로 가공한 유색미의 취반 특성

서성수,김미향,노홍균,김순동 동아시아식생활학회 2002 동아시아식생활학회지 Vol.12 No.4

Cooking characteristics of coated rice with water homogenate of citrus fruit peels (1% for rice) were investigated. The color of the coated rice both before and after cooking was dark yellow. The total content of carotenoids, hesperidin and naringin were 10.74, 2173.12 and 1468.40 ㎎% for citrus fruit peels, 0.46, 108.65 and 73.38 ㎎% for its water homogenate, 0.12, 21.73 and 14.62 ㎎% for coated rice, and 0.05, 8.67 and 5.87 ㎎% for cooked coated rice, respectively. Citrus fruits peel contained 94.22 ㎎% of asparagine, 24.88 ㎎% of methionine, 19.64 ㎎% of alaniue, and 15.37 ㎎% of r-aminoisobutyric acid as the majority free amino acids, accounting for 70% of the total free amino acids present. Total free amino acid content of the cooked coated rice increased by 15% compared to those of cooked uncoated rice. The majority of minerals in the citrus fruit peels were K and Ca, accounting for 86% of total minerals present. The mineral content of cooked coated rice was generally higher than that of the cooked uncoated rice. The cooked coated rice showed comparable hardness, gumminess and brittleness, but higher cohesiveness and springiness than the cooked uncoated rice. There were no differences in sweet and bitter taste between the cooked uncoated and coated rice. However, the cooked coated rice showed higher sensory scores for color acceptability, savory taste and overall acceptability than the cooked uncoated rice.

한약개발에 관한 연구(第Ⅱ報) : 왕자귀나무 Albizzia coreana Nakai의 활성성분 및 행동약리학적 연구(2) Studies on the behavioral pharmacology and the activated constituents of Albizzia coreana Nakai(2)

徐成勳,陸昌洙,姜三植 慶熙大學校 1987 論文集 Vol.16 No.-

Albizzia coreana belonging to Leguminosae was firstly collected from southern area of Korea in 1930 by Dr. Nakal. A deciduous tree(higher:3∼5m). Leaves bipinnate, leablet(20∼45㎜), entire, 6-10 pairs. Flowers in axillary long-peduncled heads, pale yellowish. pods thin(width:2㎝. length 7∼12㎝), Seeds(Width:4-5㎜, length 7㎜) The stem bark(Albizia coreana) are used medicinally(folk medicine). Prescreibed as sedative in insonmia, in a state of deep depression and nervosity. Dose 6∼12gm.(powdered) The chemical components of the methanol extracts of Leaves, stem bark and root barks of Albizzia coreana Nakai. From the stem bark of Albizzia coreana, sapogenin, 3β, 21 β-dihydroxyolean-12-en-28-vic acid methylester, 3β-hydroxyolean-12-en-28-oic acid and acacic acid lactone were isolated and characterized by chemical and spectral analysis. β-sitosterol, cholesterol and octadecanoic acid were isolated from the stem bark and leaves. Flavone and flavonol glycosides, quercetin-3-L-rhammoside, quercetin-3-0-glucoside and quercetin-3-0-galactoside were isolated from the Albizzia leaves and identified by spectral data.

주사전자현미경을 이용한 온실가루이(Trialeurodes vaporarium) 성충 부속지의 외부 미세구조 관찰

서미자,김기덕,김남성,박수진,채순용,윤영남 충남대학교 농업과학연구소 1999 농업과학연구 Vol.26 No.2

온실가루이의 외부형태적 특징을 주사전자현미경 사진을 통해 관찰하였다. 우선 이들은 포탄모양의 알을 산란하는데 짧은 갈고리모양의 구조에 의해 잎 뒷면에 붙어있는 것이 확인되었다. 촉각의 길이는 0.3㎜로 전체가 6마디로 구성되어 있고, 첫마디는 굵고 짧으며 둘째 마디부터 가늘고 긴 채찍모양을 하고 있다. 끝마디인 6번째 마디의 끝에는 길이가 10㎛정도의 가늘고 비교적 긴 감각기를 가지고 있어 기주를 탐색하는 과정에서 식물체의 표면을 탐지하는데 사용하는 것으로 사료되며, 바로 밑부분에는 길이가 7-8㎛정도의 비교적 굵은 감각기 2개가 존재하고 있는 것으로 확인되었다. 이 감각기는 반대편에는 존재하고 있지 않은 비대칭 분포를 보이고 있으며, 또한 두개의 모양이 서로 상이함으로 볼 수 있다. 이들의 기능은 주로 기주식물을 탐색하거나 후각기능의 화학적 감각기의 역할을 하는 것으로 추정할 수 있다. 섭식행동이 이루어지는 온실가루이 구기는 전형적인 piercing-sucking type으로, 구침이 길게 잘 발달되어 있다. 구기의 끝부분은 10여개의 미세감각기가 분포고 있어 식물체 표면을 탐색하고 맛을 보는 미각기능을 하고 있으리라 추측할수 있다. 구침은 종종 구기에서 분리되기도 하지만, 구침을 잡아주는 지지대가 기부쪽에 자리하고 있음을 알 수 있다. 구침은 두 개의 반원형이 붙어 있는 형상을 하고 있으며, 다른 흡즙형 구침과는 달리 톱날모양의 구조를 볼 수 없었다. 한편 온실가루이의 다리 끝에 붙어 있는 발톱은 식물체에 고정시키기 위한 구조로 보이는 두 개의 갈고리 형태의 발톱과 그 사이에 중앙지지대 형태의 구조인 paranychium을 포함하여 3갈래의 구조를 하고 있다. External morphology characteristics of the greenhouse whitefly, Trialeurodes vaporarium were investigated by scanning electron microscopy. The antennae of the greenhouse whitefly was 6 segments, rod-shape, and 0.3mm length. On the 6th segment, there were many sensilla for searching host-plant as olfactory receptor. The mouthpart of the greenhouse whitefly was a piercing-sucing type, then its stylet was well developed for piercing plant leaf tissue. Claw of the foreleg was a 3-war hook shape including paranychium for attaching plant surface to pierce and lay egg.

에너지법을 이용한 2경간 연속곡선보의 해석

서상근,김은수,장병순 부산대학교 생산기술연구소 2000 生産技術硏究所論文集 Vol.59 No.-

최근 고속도로 교량이나 입체교차로등에 평면곡선보의 사용이 증가하고 있다. 구조적인 복잡함 때문에 곡선교는 휨응력 뿐만아니라 비틀림응력까지 받게 된다. 통상적으로, 곡선교는 휨비틂이론으로 해석되는데 곡선교의 해석에는 ��綢늣염倖�무시한 보이론과 ��綢늣염倖�고려한 보이론이 있다. 본 논문에서는 ��綢늣염倖�고려한 휨비틈이론에 기초를 두고 단순지지 곡선보의 단면력과 변위를 결정하고 에너지법을 사용하여 2경간 연속 곡선보에 대한 탄성방정식을 유도하였다. 또한 실하중을 받고 있는 2경간 연속 곡선보의 단면력과 변위를 구하였다. The use of horizontally curved girder bridge has increased considerably for highway bridge and interchanges. Due to the geometric complexities, curved girder are subjected to not only flexural stresses but also significant torsional stresses. Usually, a curved girder is analyzed by the flexural torsional theory. There are several theories which are available for the analysis for the curved girders ; beam theory ignoring the warping-torsional effects and beam theory considering the warping torsional effects. In this paper, the stress resultants and displacements of simply supported curved girder based on the flexural torsional theory considering torsional warping effects are determined. And elastic equations of two-span continuous curved girder are obtained by using energy method. Also, bending moment diagram, warping moment diagram, torsional moment diagram, shearing force diagram, and deflection diagram of two-span continuous curved girder bridge applying vertical loads and uniform loads are presented.

안근성 중증근무력증이 동반된 갑상선 기능항진증의 임상상 : Report of Six Cases

서지영,김두만,김현규,최철수,임성희,유재명,최문기,유형준,박성우,김형철,송홍기,김덕환 대한내분비학회 2000 Endocrinology and metabolism Vol.15 No.4·5

[논문]지적경계 불일치의 개선방안에 관한 연구 -주민과 전문가 의식 조사를 중심으로-

서갑수,이성호 釜山大學校 都市問題硏究所 2004 都市硏究報 Vol.16 No.-

Initially, cadastre of South Korea has begun in 1910's However, some problem are followed by lack of repletion and development of the system now. Especially, there is no solution about the problem of cadastral inconistence under the present condition. This study was conducted a survey of consciousness concerning boundary. This study aims at presentation of an obectice index of policy establishment, and furnishing accurate data through surveying of consciousness about cadastral boundary of residents and cadastral specialists.