• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.220-225
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• 2003

Recent issue of optical actuator is applying to mobile device. It leads actuator to become smaller than conventional type. This paper proposes the design of micro actuator plate spring and analysis of its vibration characteristic. Considering natural frequency of spindle motor, 1st and 2nd eigenfrequency of micro actuator must avoid its natural frequency. First, magnetic circuit is designed by using fine pattern coil and magnetic force is acquired by simulation program. Then, concept design is achieved by topology optimization. From concept design, micro actuator plate spring is embodied through DOE(design of experiment). Finally, considering vibration characteristic simultaneously, optimal plate spring design is determined by RSM(response surface method).

• 한국정보과학회논문지:소프트웨어및응용
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• 제36권2호
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• pp.131-143
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• 2009

인간이 최소 에너지를 소비하면서 자연스럽고 안정된 상태로 보행한다는 것에 착안하여, 본 논문은 인간 보행의 COG 궤적을 분석함으로써 인간형 이족로봇의 자연스러운 보행에 관한 연구를 수행한다. 이를 위해서 본 논문은 ssgittal plane과 frontal plane상의 보행 영상으로부터 계측된 COG 궤적을 고려함으로써 안정적이고 에너지를 최소화하는 자연스러운 이족로봇의 보행 패턴을 생성한다. 인간과 이족 로봇은 기구학적인 형태는 유사하지만 자유도에 있어 많은 차이를 의이기 때문에 추출된 인간 관절의 회전력을 이족로봇에 바로 적응할 수 없다. 본 논문에서는 인간의 보행패턴으로부터 계측된 각 관절의 회전력과 인간의 COG 궤적으로부터 계산된 ZMP을 이용하는 적응적 보행 패턴 생성 GA 알고리즘을 통해 5-link 이족로봇 모델의 보행패턴을 생성한다. 제안된 알고리즘은 인간의 각 관절의 회전력과 ZMP 궤적을 고려하기 때문에 인간과 같이 유연하고 에너지 소비를 최소화하는 인간형 이족로봇의 보행패턴을 생성한다. 본 논문은 역기구학을 이용한 일반적인 방법과 제안하는 방법에 의해 생성된 보행 패턴을 각각 5-link 이족로봇 모델에 적용하여 시각적인 측면과 에너지 효율측면에서 평가함으로써 제안하는 알고리즘의 우수성을 입증하였다.

• 통합자연과학논문집
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• 제4권4호
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• pp.311-314
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• 2011

Application of self-assembled monolayers (SAMs) to the fabrication of organic thin film transistor has been recently reported very often since it can help to provide ohmic contact between films as well as to form simple and effective electrode pattern. Accordingly, quality of these ultra-thin films is becoming more imperative. In this study, in order to manufacture a high quality SAM pattern, a hydrophobic alkylsilane monolayer and a hydrophilic aminosilane monolayer were selectively coated on $SiO_2$ surface through the consecutive procedures of a micro-contact printing (${\mu}CP$) and dip-coating methods under extremely dry condition. On a SAM pattern cleaned with SC1 solution immediately after ${\mu}CP$, poly(3,4-ethylenedioxythiophene) (PEDOT) source and drain electrode array were very selectively and nicely vapour phase polymerized. On the other side, on a SC1-untreated SAM pattern, PEDOT array was very poorly polymerized. It strongly suggests that the SC1 cleaning process effectively removes unwanted contaminants on SAM pattern, thereby resulting in very selective growth of PEDOT electrode pattern.

• 대한기계학회논문집B
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• 제21권2호
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• pp.252-263
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• 1997

Steady-state two-dimensional natural convective heat transfer in horizontal cylindrical annuli was studied by solving the governing equations based on the primitive variables. Emphasis was put on the occurrence of the multiple solutions at a given set of parameter values, and on the determination of the bifurcation points at which those multiple solutions begin to branch out. The multicellular flow pattern from the results of melting process in an isothermally heated horizontal cylinder for high Rayleigh numbers, was used as initial guesses for the field variables. This was succeeded in new bifurcation point to tetracellular solutions for an identical set of parameter variables of previous works. The close examination of flow pattern transition around bifurcation point was also conducted. It was found that the mechanisms of flow transition are different depending on the critical Rayleigh number of bifurcation point.

• 한국생활과학회지
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• 제10권2호
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• pp.205-213
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• 2001

A survey was conducted to investigate the intake pattern of health supplements and health foods by using questionnaire. The data were collected from 395 adults over middle age and analyzed with SAS program. The natural foods were most frequently taken among health supplements and health foods for health. There was no difference in pattern of health supplements or health foods intake between male and female. The item taken over 20% of subjects was health drinks, green tea, ginseng product, dietary fiber drink, honey, general tea, tonic medicine from natural foods, vitamin B, vitamin C from nutrition supplements, and Lactobacillus product from health supplements. As the main reason for taking health supplements or health foods, the male indicated recovery of fatigue and improvement of health, but the female indicated recovery of fatigue and protection or treatment on disease(p<0.001). The frequency of taking health supplements or health foods was once a day. About the effect of health foods 70.1%, of subjects answered not bad and 25% responded very helpful for their health. Twenty percent of subjects experienced side effects such as diarrhea. The results showed that the proper education program should be developed for consumer to choose suitable health supplements or health foods according to their dietary life and health condition.

• Journal of Electrical Engineering and Technology
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• 제11권3호
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• pp.699-706
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• 2016

Partial discharges (PD) lead to the degradation of high voltage cables and accessories. PD activities occur due to the existence of impurities, voids, contaminants, defects and protrusions during the manufacture and installation of power cables. Commonly, insulation failures occur at cable joints and terminations, caused by inhomogeneous electric field distributions. In this work, a blend of natural rubber (NR) and linear low density polyethylene (LLDPE) was investigated, and the optimal formulation of the blend that could resist PD was discussed. The experiments were conducted under a constant high voltage stress test of 6.5 kV AC and the magnitude of partial discharge activities was recorded using the CIGRE method II. Pattern analysis of PD signals was performed along with the interpretation of morphological changes. The results showed that the addition of 10 wt% of NR and 5 wt% of Alumina Trihydrate (ATH) provided promising results in resisting PD activities. However, as the NR content increased, more micropores existed, thus resulting in increased PD activities within the samples.

• Reproductive and Developmental Biology
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• 제29권4호
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• pp.259-267
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• 2005

The present study was conducted to investigate gelatinolytic activities in HAM and to determine whether there are any changes in gelatinolytic activity profiles when the cells are cultured in hepatogenic medium. Placenta was obtained during caesarean section of the volunteers, with informed consent. HAM were isolated from amniotic membrane using collagenase type A HAM were cultured in hepatogenic medium for 3 weeks and the conditioned media were obtained at day 7, 14 and 21. The zymographic pattern of gelatinolytic activity of the HAM did not undergo a change during passages. When the HAM were cultured in a fibronectin-coated dishes in a hepatogenic medium, there was no significant difference of the gelatinase pattern between before and after culture. However, when bFGF was added to the culture, a dramatic increase of 62kDa and 59kDa gelatinases was observed. Interestingly, when ITS instead of FN was present, HAM-conditioned medium also showed a similar increase of both gelatinases. Immunoblotting analysis demonstrated that both 62kDa and 59kDa gelatinases were the active form of MMP-2 resulting from the turnover of MMP-2 proform. Futher study will be necessary to determine the relationship between bFGF and active MMP-2 during hepatogenesis of HAM.

• 대한기계학회논문집
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• 제10권2호
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• pp.247-256
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• 1986

본 연구에서는 종횡비가 0.2인 직각 밀폐용기내에서 소금물을 시험유체로 하여 양단의 온도 및 농도차가 수평방향으로 가해지는 경우(CASE 1,2) 밀폐용기내 에서의 유동현상과 열전달 특성을 온도 및 농도분포, 흐름의 가시화를 통해 실험적 으로 관찰, 조사하였다

• Clinical and Experimental Reproductive Medicine
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• 제13권1호
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• pp.39-51
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• 1986

This experiment has been done to evaluate the relationship between the follicular atresia and the protein patterns on electrophoreais of the follicular fluids in porcine ovary. The protein concentration of the follicular fluids was lower than that of serum, and gradually decreased as the follicle siae became larger. The number of protein bands of follicular fluid on electrophoresis was less than that of serum, and gradually increased as follicle size became larger. Three specific bands were detected on disc PAGE and one band(M W. 75,000) on SDS PAGE in the follicular fluids, while not in serum. One band (A) at ${\beta}$-globulin region on disc PAGE became heavier, as follicles became atretic. Two bands less than(M. W. 20,000) were detected only in the large follicular fluid. Another band(M. W. 43,000) was not detected in necrotic group, whereas all other groups showed it. It could be concluded that the component and composition of the proteins follicular fluids changes according to the follicular size during atresia. Therefore detection of the changing pattern of proteins in the follicular fluid can be used as a basic criterion for the identification of follicular atretic stage.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2005년도 국제학술심포지움 The 44th Annual Meeting of Korean Society for Life Science
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• pp.115-115
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• 2005