• 한국전기전자재료학회논문지
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• 제20권10호
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• pp.901-906
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• 2007

In this study, we measured the partial discharge phenomenon of inside the closed switchgear, using ultra wide band antenna. The characteristics of $\Phi-q-n$ in the normal state are stable, and confirmed at less than 0.01, but in proceeding states, about 2 times larger. And in the abnormal state, it grew hundreds of times larger compared with normal state. According to K-means analysis, if slant of discharge characteristics is a straight line close to "0" and standard deviation is small, it is in a normal state. However if we can find a peak from K-means clusters and standard deviation to be large, it is in an abnormal state.

• 대한기계학회논문집A
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• 제24권5호
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• pp.1133-1145
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• 2000

It is necessary to develop an efficient analysis method to identify the dynamic characteristics of a large mechanical structure and update its finite element model. That is because these processes need the huge computation of a large structure and iterative estimation due to the use of the first- order sensitivity. To efficiently carry out these processes, a new method, called the generalized free-interface mode sensitivity method, has been proposed in the authors' preceeding paper. This method is based on substructuring approach such as a free-interface method and a generalized synthesis algorithm. In this paper, the proposed method is applied to the model updating of a car body structure to verify its accuracy and reliability for a large mechanical structure.

• The Journal of Korean Physical Therapy
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• 제11권1호
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• pp.167-177
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• 1999

Biomechanics is an important scientific foundation of physical therapy and is used to relate kinematics, kinetics, statics and dynamics for comprehencing human movement. The knee is well studied for demonstrating biomechanical analyses of joint because of its simplicity. The purposes of this study were 1)to provide categories and concepts of biomechanics, 2) to apply these concepts to knee movement involving daily living and gait, and 3) to review current and preceeding researches about biomechanics of knee. Thus, physical therapiestes in clinic may be helped understand of movement which includes considerations of description and production related force, moment and power.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권5호
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• pp.366-371
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• 2000

The aim of this study was to investigate the efficiency of the pentagalloic acid compound in inhibiting the metal ions and cell lines that mediate in low density lipoprotein (LDL) oxidation. Pentagalloic acid prolonged the lag time preceeding the onset of conjugated diene formation. In chemically induced LDL oxidation by Cu$^2$(sup)+ plus hydrogen peroxide or peroxyl radical generated by 2, 2-azo-vis (2-amidino propane) hydrochloride (AAPH), pentagalloic acid inhibited LDL oxidation as monitored by measuring the thiobarbituric acid reactive substances(TBARS), malondialdehyde(MDA), and gel electrophoretic mobility. The physiological relevance of the antioxidative activity was validated at the cellular level where pentagalloic acid inhibited mouse macrophage J774 and endothelial cell-mediated LDL oxidation. When compared with several other antioxidants, pentagalloic acid showed a much higher ability than naturally occuring antioxidants, ${\alpha}$-tocopherol and ascorbic acid, and the synthetic antioxidant, probucol.

• 한국과학교육학회지
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• 제11권1호
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• pp.25-36
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• 1991

For the purpose of extending the fields of biological preconceptual studies, the conceptions of plant classification, which have not been researched on them in korea, were selected and a questionnaire were administered to a sample of a total of 965 students at elementary and secondary school levels of korea. Many elementary school students have the alternative conceptions that plants are not alive. The misconceptions in plant classification are partly caused by the uncertainty of biological terms. To serve the teachers, who have difficulty in teaching them, the preceeding results are summarised with Composition the misconception maps.

• Journal of Plant Biology
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• 제29권4호
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• pp.233-242
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• 1986

In order to pursue some physiological studies on organogenesis in ginseng tissue culture, ginseng root explants were cultured on a modified MS medium containing NAA and kinetin. The activities of peroxidase and some enzymes were investigated and their isoenzyme patterns were also observed. The activity of peroxidase decreased by 20% in one week's culture and increased thereafter by 80% in culturing for 7 weeks compared with the control group. Glucose-6-phosphate dehydrogenase activity increased by 400% after culturing for 5 weeks and increased during the days preceeding root formation. The activities of glutamate dehydrogenase and acid phosphatase also increased during the culture. After 3 weeks' culture, new peroxidase isozyme (pH 7.6) appeared and 7 weeks' culture, another new peroxidase isozyme (pH unidentified) appeared. These patterns were also identified by using FPLC. After 7 weeks' culture, a new esterase isozyme of pH 8.5 appeared and isozyme patterns of acid phosphatase were quite changed compared with the isozyme patterns of tissue cultured for 5 weeks. In so far as these new isoenzymes appear distinctively after 7 weeks' culture, root differentiation is supposed to be induced after 7 weeks' culture.

• 한국자동차공학회논문집
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• 제7권7호
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• pp.202-213
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• 1999

Adaptive Cruise Control (ACC) is one of key features on intelligent Transportation System(ITS). In ACC, the steering is done by a driver, but the engine throttle valve and the brake are controlled electronically. The relative velocity and distance from the preceeding vehicle are measured by radars or image processing units and relevant vehicular spacing is maintained in ACC control systems. In this study, vehicle longitudinal dynamics are modeled to simulate vehicle longitudinal maneuver and to design longtitudinal controllers for ACC vehicles. The control algorithm is designed based on the modeled vehicle longitudinal dynamics using a non-linear sliding mode control method. To verity the performance of the control algorithm, a real time numerical simulation program is developed on a Silicon Graphics workstation using C-language . A real time graphic program is alos develpe and integrated with the numerical simulation program.

• 한국수소및신에너지학회논문집
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• 제14권2호
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• pp.131-137
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• 2003

Backfire occurrence must be controlled for the practical use of hydrogen fueled engine. It was found from preceeding studies that crevice volume around piston rings could effect a backfire occurrence. In this study, a possible countermeasure to backfire occurrence was evaluated by using multi point ignition method around piston ring. The results showed that backfire limited equivalence ratio was increased by a little due to a enhancing effect of mixture combustion around piston crevice volume.

• 한국의사학회지
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• 제20권2호
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• pp.65-69
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• 2007

Although a table of descent is a mandatory primary source for studying medical persons, but most of those who practiced medicine were not but of step families. Because members of step families are not usually recorded accurately, preceeding studies did not put much emphasis on them. But as more researchers study biography and the number of studies done on historical figures are increasing tremendously, its value as a source has increased as well. In order to research a person, obtaining background information is a priority, which includes to what family they belong to, to what specific branch of the family they belong to, etc. Whether or not the person has ever worked with a public institution is important as well.

• 한국멀티미디어학회논문지
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• 제3권2호
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• pp.184-191
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• 2000

본 논문에서는 선행 연구한 $\Delta$-형 필터를 토대로 하여 이의 특성을 종합적으로 비교 분석하였다. 먼저 화면 확장을 위한 $\Delta$-형 필터의 알고리즘에 대해서 논하였고, 이의 특성, 즉 $\Delta$-형 필터의 에지보존특성과 알고리즘에 근거하여 기존 방식들과의 연산량을 비교하였다. 그리고 제안한 방식과 기존의 알고리즘을 PSNR을 도입하여 정량적으로 비교하였으며, Synopsys VHDL에 의한 구현을 통하여 하드웨어의 복잡성을 비교하였다. 마지막으로 $\Delta$-형 필터의 특징과 trade off에 대해서 논하였다.