• 한국산림과학회지
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• 제95권1호
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• pp.55-59
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• 2006

본 연구는 희귀식물 꼬리진달래의 형태적 변이를 분석하여 종내 변이를 구명하며, 나아가 조경수로써 우량한 개체의 선발과 유전자원을 보호하며 꼬리진달래의 보호, 관리함에 있어 기초 자료를 제공하고자 실시하였다. 꼬리진달래의 형태적 특성을 고찰하기 위하여 6개 산지를 선정하고, 18가지 형질들을 조사한 결과, 꽃잎의 형질에서는 월악산의 것이 큰 경향을 나타낸 반면에 봉화의 것이 가장 작은 경향을 나타내었으며, 잎의 형질에서는 연하리의 형질이 가장 큰 경향을 나타내었으며, 봉화의 것이 가장 작게 나타났다. 형태적 특성들에 대한 주성분분석 결과, 제 1주성분의 기여도가 전체변이의 41.6%, 고유값이 1이상인 제 3주성분까지의 기여도는 전체변이의 81.5%였다. 제 1주성분은 꽃잎 길이(PL), 엽 길이(LL) 폭(LW), 암술머리 길이(SL) 특성이 높은 상관관계를 나타냈으며, 제 2주성분의 기여율은 21.1%로서 엽병 길이(PTL), 약 길이(AL) 특성이 높은 상관관계를 나타내었다. 또한, 제 3주성분의 기여율은 22.6%로서, 소화경 길이(FPL), 수술대 길이(FL) 특성이 높은 상관관계를 나타내었다 주성분 1, 2, 3의 주요특성들은 꼬리진달래 산지간 형질 분류에 중요한 정보를 주는 요인으로 나타났다. 조사 분석된 산지의 형태적 특성들을 기초로 하여 유집분석을 실시한 결과를 종합하여 살펴볼 때, 크게 3개의 그룹으로 구분할 수 있으며, 제 1그룹은 영월군 직동리이며, 제 2그룹은 충청북도 월악산, 영윌군 연하리, 제 3그룹은 태백, 봉화, 삼척 지역이 속히는 것으로 분석되었다.

• 대한음성학회지:말소리
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• 제50호
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• pp.1-22
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• 2004

The aim of this paper is to show what are the sociolinguistic variables of word-initial length loss in Seoul dialect. 350 people were inquired to pronounce 40 words. Among the informants, 152 were male, and 198 were female. In terms of their age, 49 were twenties, 70 were thirties, 69 were forties, 71 were fifties, and 91 were above sixties. According to our statistics, 18 words show sociolinguistic variation by age, and sex was not a variable. So we can conclude that Seoul dialect is undergoing length loss by age at least. But we need to enlarge the number of words and informants and we also need to adopt other variables like social level, education etc for better understanding of Seoul dialect.

• 대한기계학회논문집B
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• 제30권2호
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• pp.161-169
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• 2006

The spray characteristics of liquid jet in cross flow with variation of injection angle are numerically studied. Numerical analysis was carried out using KIVA code, which was modified to be suitable for simulating liquid jet ejected into cross flow. Wave model and Kelvin-Helmholtz(KH)/Rayleigh-Taylor(RT) hybrid model were used for the purpose of analyzing liquid column, ligament, and the breakup of droplet. Numerical results were compared with experimental data in order to verify the reliability of the physical model. Liquid jet penetration length, volume flux, droplet velocity profile and SMD were obtained. Penetration length increases as flow velocity decreases and injection velocity increases. From the bottom wall, the SMD increases as vertical distance increases. Also the SMD decreases as injection angle increases.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권12호
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• pp.616-619
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• 2004

Electrical circuits with semiconductor are very weak against lightning surge. The surge protective devices for electronic circuit and AC power lines are becoming more widely used. To achieve effective method of surge protection, there are needs for correlation between lightning surge and indoor wire length or installation height of indoor wire. The aim of this present work is to investigate the propagation characteristics of lightning surge according to variation of wire length. As a consequence, the maximum voltage at the end of the open wire in proportion to length of indoor wire. Therefore this result may be raw data for establishment of surge protection system.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.551-552
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• 2008

This paper presets a results of frequency response in variation of wire bonding length. A gold ball bonding is used as a wire bonding process, and a DPDT(double pole double thru) switch is adapted as a device for test. Wire length is ranged from 442um to 833um and a measured frequency range is from 1 GHz to 6 GHz. Little difference are measured in insertion loss and return loss depending on wire length. Measured S21 and S11 are -0.58 dB and -17.7 dB, respectively. S21 insertion loss is rising up and S11 insertion loss is falling down as the frequency is increased.

• 산업기술연구
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• 제19권
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• pp.59-65
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• 1999

This study is to analyze turbulent flow over a backward-facing step in a rectangular duct. The side wall effects on the internal flow were determined by varying the aspect ratio(defined as the step span-to-height ratio) from 1 to 20. In the flow behind a backward-facing step, separation, recirculation and redeveloping is occurred frequently. These phenomena appear in a particular variation by varying the aspect ratio. The results show that the aspect ratio has an influence on the velocity and reattachment length. When the AR is increased, the reattachment length is increased. For 6 over aspect ration, the rate of increase is decreased. The length of recirculation in the upper corner is increased, as the increase of aspect ration. It's width is not changed in the variation of aspect ration. The transverse, streamwise and spanwise velocities were decreased along the flow down stream of the step.

• 한국전기전자재료학회논문지
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• 제17권10호
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• pp.1034-1040
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• 2004

The latch-up current and switching characteristics of MOS-Controlled Thyristor(MCT) are studied with variation of the channel length and impurity concentration. The proposed MCT power device has the lateral structure and P-epitaxial layer in substrate. Two dimensional MEDICI simulator is used to study the latch-up current and forward voltage-drop from the characteristics of I-V and the switching characteristics with variation of impurity concentration. The channel length and impurity concentration of the proposed MCT power device show the strong affect on the anode current and turn-off time. The increase of impurity concentration in P and N channels is found to give the increase of latch-up current and forward voltage-drop.

• 설비공학논문집
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• 제26권12호
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• pp.553-558
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• 2014

Geothermal energy can be used with a geothermal heat pump or an earth-to-air heat exchange system (EAHES), which is referred to as a "cooling tube" in Korea. In this study, we suggest EAHES burial guidelines in terms of the parameters of buried pipe length and air velocity regarding the exit air temperature of EAHES. The exit air temperature for EAHES in three regions (Changwon, Busan and Seoul) was calculated with variation in buried pipe length and air velocity at ${\Phi}100mm$ and ${\Phi}200mm$. In conclusion, variation in the buried pipe length is more effective than that of air velocity to achieve the required exit air temperature.

• 대한화장품학회지
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• 제16권1호
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• pp.18-29
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• 1990

In this report, the variation of skin surface between before treatment and after treatment was investigated by skin image analyzer. The 30 volunteers were applied cream and lotion on the forearm Inside for 4 weeks, and the measurement parameter of skirl surface was adopted peak, length, height, and width. The results were as follows ; 1. variation trends of parameters was showed that number of peaks were increased, but length, height and width were decreased. 2. The order of improvement for skin surface are as follow ; height > length > peak > width. 3. And also disclosed that the number of peak has a correlation with width, and length has a correlation with height.

• 한국광학회:학술대회논문집
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• 한국광학회 1989년도 제4회 파동 및 레이저 학술발표회 4th Conference on Waves and lasers 논문집 - 한국광학회
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• pp.113-118
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• 1989

By using the single mode optical fiber, we fabricated Fiber-optic Fabry-Perot interferometer (FFPI). The change over a wide range in the optical path length of a FFPI is observed. The temporal movement of the interference fringes by external condition to P.Z. T) is converted to circular motion on an oscilloscope display and then recorded with a micro-computer. The two output voltages of the D/A converters are applied to X and Y terminals of oscilloscope to display circular motion on oscilloscope. Thus the direction of phase shift can be determined with observing the direction of circular motion. The variation of the optical length can be measured by calculating the angle of spot of circle with an accuracy of λ/90 wave length due to variation of temperature in this system 2.7x10-4$^{\circ}C$.