• 한국전기전자재료학회논문지
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• 제16권2호
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• pp.168-172
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• 2003

The electron transport coefficients in Air is analysed in range of E/Nvalues from 100~1000(Td) by a MCS and BE method. This paper have calculated W, ND$\sub$L/, ND$\sub$T/, Mean energy mixtures by N$_2$+O$_2$. The results gained that the values of the electron swarm parameters such as the electron drift velocity, longitudinal and transverse diffusion coefficients.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2002년도 추계학술대회 논문집
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• pp.89-95
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• 2002

An experimental investigation was performed to study the characteristics of turbulent swirling flow in an axisymmetric annuli. The swirl angle measurements were performed by flow visualization technique using smoke and dye liquid. Using the Particle Image Velocimetry method, this study found the time-mean velocity distribution and turbulent intensity with swirl for Re = 20,000, 30,000, 50,000, and 70,000 along longitudinal sections and the results appear to be physically reasonable.

• 대한기계학회논문집
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• 제15권6호
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• pp.1872-1885
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• 1991

본 연구에서는 자기장의 상호작용을 고려해야 하며 본 연구에서는 유한요소법 을 이용하여 전자기장 해석을 함으로써 이 문제를 해결하였다. 또한 여기서 계산된 자기압력을 이용하여 피가공재의 동적변형 거동을 유한요소법으로 해석하였다.

• 대한기계학회논문집A
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• 제30권7호
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• pp.865-872
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• 2006

High frequency induction welding is widely employed for longitudinal seam welding of small scale tubes and pipes because of its relatively high processing speed and efficiency. This research is aimed at understanding the variables that affect the quality of the high frequency induction welding. The welding variables include the welding frequency, weld speed, V-angle and tube thickness. Temperature distribution of the tube is calculated through three dimensional coupled electromagnetic and thermal FE analysis. The skin and proximity effects are considered in the electromagnetic analysis. The influence of the impeder is also analyzed. The effects of the operating welding variables on the temperature distribution are investigated quantitatively by exhibiting the heat affected zone (HAZ). The results explain the mechanism of significant enhancement of welding efficiency when the impeder is used. The proper welding conditions without the overheated edge are obtained through FE analysis.

• 한국가시화정보학회지
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• 제1권1호
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• pp.82-91
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• 2003

The study of swirl flow has been of technical and scientific interest because it has an internal recirculation field and its tangential velocity is related to the curvature of the streamline. The fluid flow for ducts or elbows of an internal engine has been much studied through numerical methods and experiments, but studies about swirl flow has been insufficient. Using the PIV (Particle Image Velocimetry) method, this study found the time-mean velocity distribution, time-mean turbulent intensity, with swirl and without swirl flow for Re=10,000, 15,000, 20,000, and 25,000 along longitudinal sections and the results appear to be physically reasonable. In addition, axial velocity distribution is compared with that of Jeong's, Kodadadi's and Murakami's. It was found that the highest velocity of swirl and non-swirl flow occurs in the opposite position at the center of a round tube, $\phi$=45$^{\circ}$

• 전기학회논문지P
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• 제64권3호
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• pp.125-129
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• 2015

Energy distribution function for electrons in SF6-Ar mixtures gas used by MCS-BEq algorithm has been analysed over the E/N range 30~300[Td] by a two term Boltzmann equation and a Monte Carlo Simulation using a set of electron cross sections determined by other authors experimentally the electron swarm parameters for 0.2[%] and 0.5[%] $SF_6-Ar$ mixtures were measured by time-of-flight(TOF) method, The results show that the deduced longitudinal diffusion coefficients and transverse diffusion coefficients agree reasonably well with theoretical for a rang of E/N values. The results obtained from Boltzmann equation method and Monte Carlo simulation have been compared with present and previously obtained data and respective set of electron collision cross sections of the molecules.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2003년도 한국우주과학회보 제12권2호
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• pp.81-81
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• 2003

We report the plasma blob events that were observed from KOMPSAT-1 (2250 LT, 685-km altitude) and from DMSP F15 (2130 LT,840-km altitude) in the low-latitude ionosphere. The global distribution of blobs showed a season-longitudinal dependence similar to the distribution of the equatorial plasma bubbles, although they were observed along the ${\pm}$15 dip latitudes. The blobs drifted upward relative to the ambient plasmas, and the electron temperatures and H+ proportions were lower within the blobs compared to those in the background. These characteristics of the plasma blobs are very similar to the characteristics of the equatorial plasma bubbles. Then, we suggest that the blobs were originated from the lower altitudes by the mechanism that drives an upward drift of the plasma bubbles. The blob events did not occur in a correlated way with the magnetic activity or daily variation of the solar activity.

• 유통과학연구
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• 제10권8호
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• pp.35-43
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• 2012

This study is designed to collaboratively investigate the influences of the characteristics of Internet shopping malls and the shopping traits of their users involved in e-commerce on shopping intention. With this in mind, the researchers take a look at the influences of such features of shopping malls on the web as the quality of the system, customer-support service, shopping-mall perception and security, the users' propensity to pursue pleasure and pragmatic interest on shopping intention. The study shows that all the variables suggested here have an influence on the purchase intent of Internet shopping-mall users. That is, this study cannot analyze how the purchase intent of the customers with regard to the features of Internet shopping malls has changed. Therefore it is necessary to conduct procedural researches taking longitudinal studies into consideration.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.878-881
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• 2002

Energy distribution function for electrons in $SF_6+Ar$ mixtures gas used by MCS-BEq algorithm has been analysed over the E/N range 30 ~ 300[Td] by a two term Boltzmann equation and by a Monte Carlo Simulation using a set of electron cross sections determined by other authors, experimentally the electron swarm parameters for 0.2[%] and 0.5[%] $SF_6+Ar$ mixtures were measured by time-of-flight(TOF) method, The results show that the deduced electron drift velocities, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients and mean energy agree reasonably well with theoretical for a rang of E/N values. The results obtained from Boltzmann equation method and Monte Carlo simulation have been compared with present and previously obtained data and respective set of electron collision cross sections of the molecules.

• 응용통계연구
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• 제17권2호
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• pp.185-196
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• 2004

농작물에 기주하는 해충의 밀도추정은 해충종합적 관리(Integrated Pest Management: IPM)의 중요한 연구분야이다. 이는 농약을 살포한다든지 천적을 방사하는 것과 같은 인위적인 방제관리의 성패여부가 해충밀도에 대한 정보에 의존하기 때문이다. 본 연구는 온실장미에서 서식하는 점박이응애의 밀도분포를 일반화 선형혼합모형을 통하여 분석하고 있다. 자료습득이 식물체의 일정 부위에서 반복적으로 이루어 졌기 때문에 경시적 자료분석의 개체특정(Subject-Specific: SS)방법과 모집단평균(Population-Averaged: PA)방법을 모두 사용한 후에,그 결과를 비교, 검토 하였다.