• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.700-703
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• 2003

The test method of ASTM E 756 and KS D 0076 to estimate vibration-damping properties is compared. Comparison method depending on specimen support, exciting method and calculation method for loss factor is used. Half-power bandwidth method and vibration decay method is used in the calculation method for loss factor, and Young's modulus is decided by geometric character and density for specimen and resonance frequency. Vibration measurement sensor is compared by using non-contact displacement detector, velocity detector and accelerometer. This paper is also presented the matter which is able to cause error in the measurement

• 한국자동차공학회논문집
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• 제8권1호
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• pp.23-31
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• 2000

Knock and misfire, kinds of abnormal combustion, are highly undesirable effect on the internal combustion engine. So, it is important to detect these avnormal combuition and control the ignition timing etc. to avoid these mal-effect factors in real engine system. In this study, the system which detects the knock and the misfire using by spark plug is presented. This system is based on the effect of modulation breakdown voltage(BDV) between the spark gaps. The voltage drop between spark plug electrodes, when an electrical breakdown is initiated, depends on the temperature and pressure in combustion chamber. So, we can detect knock and misfire that produce changes in gas temperature and pressure (consequently, its density) using by BDV signal change which carries information about the character of combustion.

• 한국경영과학회지
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• 제9권2호
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• pp.23-27
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• 1984

We Observe a sequence of i. i. d random variables with density f or g. Only if g is true we should stop the process. Hence. the testing problem is completely described by a stopping time. Among all stopping times with error probability of first kind not exceeding a given bound, the one-sided sequential probability ratio test has smallest expected sample size if g is true. Moreover, the generalized one-sided SPRT has smallest expected sample size for g in the class of stopping times with expected sample size under f not falling below a given bound.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.367-370
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• 1998

In this paper, based on the research of high temperature YBCO superconductor, using the Yb instead of Y, with the YbBCO superconductor powder which was combined by means of conventional solid reaction, textured directional crystal was prepared by MCP method and the character was analyzed. Mixing the starting elements and calcining at 890$^{\circ}C$, 900$^{\circ}C$, 910$^{\circ}C$, single phase YbBCO, Yb$_2$BaCuO$\sub$5/ and BaCuO$\sub$2/ were certified. And from the powder which was calcined at 900$^{\circ}C$ the, sample which became texture-growth by MCP method was well oriented. The result of DTA measurement, the fusing point of YbBCO superconductor and it\`s critical current was measured to be 979$^{\circ}C$, 87K respectively. The critical current density was obtained at the value of 700A/$\textrm{cm}^2$(77K. 0H) calculated by Bean's Model using the measured hysteresis curve of VSM.

• Bulletin of the Korean Chemical Society
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• 제30권7호
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• pp.1481-1484
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• 2009

When isolated phenol or a small phenol-solvent cluster is excited to the $S_1\;state\;of\;{\pi}{\pi}^*$ character, the hydrogen atom of the hydroxyl group dissociates via a ${\pi}{\sigma}^*$ state that is repulsive along the O-H bond. We computationally investigated the substitution effects of an amino group on the excited state hydrogen transfer reaction of phenol. The time-dependent density functional theory (TDDFT) with B3LYP functional was employed to calculate the potential energy profiles of the ${\pi}{\pi}^*$ and the ${\pi}{\sigma}^*$ excited states along the O-H coordinate, together with the orbital shape at each point, as the position of the substituent was varied. It was found that the amino substitution has an effect of lowering the ${\pi}{\sigma}^*$ state and enhancing the excited state hydrogen transfer reaction.

• 한국조경학회지
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• 제26권3호
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• pp.152-161
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• 1998

The purpose of this study was to identify remained real state of groves of enclosed village in human settlement circle. That was practiced in case of Chinan-Gun region which traditional elements had well been conservated. 48 village groves were found by site survey, reference and interview in Chinan-Gun region. 27 groves of 48 village groves were clarified as complementing village grove by classification of grove character. It was identified through survey that many were partially destructed by development and human use. The results of this study showed general, socio-behavioral characteristics, characteristics of forest state and vegetation structure of complementing village groves. Length, area, form, type, motive, location, relationship of those were analyzed to identify general characteristics. Facilities, human behavior and ownership of those were analyzed to identify socio-behavoral characteristics. Dominent species, appearing rate, height, width, density and biodiversity of upper trees were analyzed to identify forest state and vegetation structure. Interrelation of each factor were analiged and comparative review with previous studies was achieved.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.439-442
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• 2003

The test method of ASTM E 756 and JIS G 0602 to estimate vibration-damping properties is presented. Measurement method depending on specimen support, exciting method and calculation method for loss factor is used. Half-power bandwidth method and vibration decay method is used in the calculation method for loss factor, and Young's modulus is decided by geometric character and density for specimen and resonance frequency. Vibration measurement sensor is compared by using non-contact displacement detector, velocity detector and accelerometer. The cause of measurement error is also presented.

• 한국측량학회지
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• 제25권3호
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• pp.257-266
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• 2007

적조에 관한 조사는 육안과 샘플링에 의한 현지조사에 의해 일반적으로 진행되고 있다. 이와 같은 기존의 조사, 분석방법은 적조의 발생과 소멸까지의 경로를 정확하게 예측하기 곤란하였다. 이에 좀더 객관적이고 과학적인 방법으로 적조의 발생과 그 이동경로 등 시 공간적인 환경인자를 분석해 볼 필요성이 대두되고 있다. 본 연구에서는 지리정보시스템을 적용하여 적조의 공간특성을 분석하고자 Arc/Info를 활용하여 자료를 구축한 후 적조발생해역에서의 적조밀도분포를 추정하기 위해 IDW 보간법을 적용하였다. 그 후 GRID 모듈의 CON 및 SUM Function을 이용하여 밀도 1,000cells/ml이상 발생된 해역을 추출하였으며, 추출된 해역을 기준으로 날짜별로 밀도를 누적하였다. 본 연구를 통하여 적조가 발생되는 해역을 지리정보시스템에 의해 적조의 분포 현황을 시 공간적으로 판단할 수 있었으며, 적조발생지의 공간별 밀도와 누적빈도를 GIS를 적용하여 분석한 결과 최대밀도 발생해역과 최대 빈도 발생해역 모두 남해도 남면일대 해역으로서 최대 누적빈도는 49회임을 알 수 있었다. 이를 근거로 차 후 발생되는 적조발생해역에 대한 자료의 보완이 이뤄질 경우 적조 발생과 소멸까지의 이동경로를 예측 할 수 있으리라 판단된다.

• Transactions on Electrical and Electronic Materials
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• 제8권6호
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• pp.265-267
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• 2007

The liquid crystal(LC) aligning capabilities of a nematic liquid crystal(NLC) on a homeotropic polyimide(PI) surface using a new ion-beam method were studied. Exposure ion-beam of $45^{\circ}$ incidence angle shows a good LC alignment of the NLC on the homeotropic PI surface. Also, on the homeotropic PI surface, the tilt angle of the NLC by exposure ion-beam of $45^{\circ}$ incidence angle had a tendency to decrease as increased ion-beam energy density. And, on the homeotropic PI surface, the alignment character of the NLC with respect to ion-beam energy was good at 1500 eV. And we achieved satisfactory result for EO character.

• 대한공간정보학회지
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• 제18권2호
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• pp.69-78
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• 2010

유역에서의 수문지형학적 특성들은 유출현상과 깊은 상관성을 가지고 있다. 지리정보체계의 발달은 양자간의 역학관계를 규명하는데 커다란 도움을 주었다. 본 연구에서는 이러한 지형인자 중 수문응답과 밀접한 관계로 알려진 국부경사와 지표면거리에 대한 분석을 실시하였다. 그러나 이상의 지형인자는 각 pixel별 변동성이 매우 크기 때문에 DEM으로부터 추출된 자료를 직접 사용하는 것은 한계를 가지게 된다. 따라서 공간상관성을 고려한 분포도의 통계적 특성을 이용해 수문응답함수 특성과 분포된 지형학적인자간의 관계를 살펴보았다. 분석결과 국부경사는 첨두유량에, 지표면거리는 첨두유량, 평균 및 분산에 영향을 미치는 것으로 나타났다. 향후 이러한 수문지형학적 분석 기법은 DEM자료로부터 수문응답을 직접 유추할 수 있는 유용한 기법으로 발전될 수 있을 것으로 기대된다.