• 천문학회지
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• 제36권2호
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• pp.55-60
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• 2003

In Lee, Kang & Byun (2001) the discovery of Raman scattered 6545 A feature was reported in symbiotic stars and the planetary nebula M2-9. The broad emission feature around 6545 A is formed as a result of Raman scattering of He II n = 6 $\to$ n = 2 photons by atomic hydrogen. In this paper, we introduce a method to compute the equivalent width of He II $\lambda$ 1025 line and present an optical spectrum of the symbiotic star RR Telescopii as an example for a detailed illustration. In this spectrum, we pay attention to the broad H$\alpha$ wings and the Raman scattered He II 6545 feature. The broad Ha wings are also proposed to be formed through Raman scattering of continuum around Ly$\beta$ by Lee (2000), and therefore we propose that the equivalent width of the He II $\lambda$ 1025 emission line is obtained by a simple comparison of the strengths of the 6545 feature and the broad H$\alpha$ wings. We prepare a template H$\alpha$ wing profile from continuum radiation around Ly$\beta$ with the neutral scattering region that is supposed to be responsible for the formation of Raman scattered He II 6545 feature. Isolation of the 6545 feature that is blended with [N II] $\lambda$ 6548 is made by using the fact that [N II] $\lambda$ 6584 is always 3 times stronger than [N II] $\lambda$ 6548. We also fit the 6545 feature by a Gaussian which has a width 6.4 times that of the He II $\lambda$ 6527 line. A direct comparison of these two features for RR Tel yields the equivalent width $EW_{Hel025} = 2.3{\AA}$ of He II $\lambda$ 1025 line. Even though this far UV emission line is not directly observable due to heavy interstellar extinction, nearby He II lines such as He II $\lambda$ 1085 line may be observed using far UV space instruments, which will verify this calculation and hence the origins of various features occurring in spectra around H$\alpha$.

• 한국지구과학회지
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• 제38권1호
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• pp.1-10
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• 2017

공생별 AG Peg는 적색거성(GS)과 백색왜성(WD)으로 구성된 성운으로 둘러싸인 쌍성계이다. AG Peg의 분광자료는 1998년, 2001년, 그리고 2002년의 세 시기에 미국 Lick 천문대에서 관측한 자료로 HI 발머 방출선 자료를 분석하였다. AG Peg의 선세기와 폭은 각 시기에 따라 변하는데, $H{\alpha}$와 $H{\beta}$ 선에서 모두 청색편이, 적색편이, 넓은 폭 성분이 나타났다. 가스 성운의 운동학적 특성을 보여주는 방출선은 WD주변에 형성된 강착원반의 반경이 매우 큼을 보여준다. 관측자의 시선 방향을 고려하면, 1998년 관측은 AG Peg의 GS와 WD가 나란히 하늘에 있는 반면, 2002년에는 WD가 GS의 전면에, 2001년에는 WD가 GS의 뒷면에 위치하였다. 이러한 상대적인 위치와 분광선의 변화를 고려하여, 우리는 GS에서 WD로의 가스유입이 지속적으로 이루어지고, 그 결과 형성된 두꺼운 원반의 회전이 관측된 분광선 윤곽의 형성을 가져온 것으로 결론지었다.

• 유통과학연구
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• 제15권10호
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• pp.81-92
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• 2017

Purpose - One of the main objectives of this paper is to identify the most effective type of social media and to analyze the priority of blogs by their informational attributes in the aspect of their impacts on word-of-mouth intention(WOM) in on-line markets. Research design, data, and methodology - We set 'attitude' variable in the middle to see if there is mediating effects between blog information and word-of-mouth intention. We conducted a survey by questionnaire and received 206 answers. Employing the OLS statistical methods through the SPSS package, we tested our hypotheses. Results - Some of the main results are the followings. First, blog, micro-blog, and profile-based services showed significant effects on WOM, while Internet community and mini-homepages are not significant. Second, blog has positive impacts on WOM. Third, attitude has perfect mediating effects between blog and WOM. Fourth, in terms of effects on WOM, interactivity shows the first priority and reliability and usability follows. Finally, attitude has a more significant effect for users of 3 types of blog compared with those of 2 types. Conclusions - In this paper, we analyzed the effects of social network services by type and identified the priority among various attributes of information contained in blogs. It would provide businesses with viable strategic options to establish public relations in their sales promotion.

• 천문학회지
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• 제38권2호
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• pp.279-282
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• 2005

We report the millimeter-wave radio observations of molecular cloud cores in Taurus. The observed line is the $N_2H^+$ emission at 93 GHz, which is known to be less affected by molecular depletion. We have compared starless (IRAS-less) cores with star-forming cores. We found that there is no large difference between starless and star-forming cores, in core radius, linewidth, core mass, and radial intensity profile. Our result is in contrast with the result obtained by using a popular molecular line, in which starless cores are larger and less condensed. We suggest that different results mainly come from whether the employed molecular line is affected by depletion or not. We made a virial analysis, and found that both starless and star-forming cores are not far from the critical equilibrium state, in Taurus. Together with the fact that Taurus cores are almost thermally supported, we conclude that starless Taurus cores evolve to star formation without dissipating turbulence. The critical equilibrium state in the virial analysis corresponds to the critical Bonnor-Ebert sphere in the Bonnor-Ebert analysis (Nakano 1998). It is suggested that the initial condition of the molecular cloud cores/globules for star formation is close to the critical equilibrium state/critical Bonnor-Ebert sphere, in the low-mass star forming region.

• 동의생리병리학회지
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• 제18권5호
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• pp.1291-1300
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• 2004

Baicalin, a biologically active flavonoid form the roots of Scutallaria baicalensis (Skullcap), have been reported to not only function as anti-oxidants but also cause anticancer effect. We investigated the mechanism of baicalin-induced cytotoxicity and the macro scale gene expression analysis in leukemia cell line, HL-60 cells. Baicalin (10 μM) were used to treat the cells for 6h, 12h, 24h, 48h and 72h. In a human cDNAchip study of 65,000 genes evaluated 6, 12, 24, 48. 72 hours after treated with Baicalin in HL-60 cells. Hierarchical cluster against the genes which showed expression changes by more than two fold. One hundred one genes were grouped into 6 clusters according to their profile of expression by a hierarchical clustering algorithm. For genes differentially expressed in response to baicalin treatment, we tested functional classes based on Gene Ontology (GO) terms. This study provides the most comprehensive available survey of gene expression changes in response to baicalin treatment in HL-60 cell line.

• 전기전자학회논문지
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• 제5권2호
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• pp.146-152
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• 2001

본 논문에서는 배전 계통에서 전압 파형 개선을 위하여 배전용 정지형 보상기(DSTATCOM)의 제어 기법 2가지를 보였다. 1선 지락 사고 시에 제시한 방법을 이용한 시뮬레이션을 통해 선로 전압 파형이 개선됨을 알 수 있다. 또한 비제어 및 PI 제어와 LQR 제어를 비교하였다. 요구되는 응답 특성 및 제어 효과에서 LQR 제어가 우수함을 보이고 PSCAD/EMTDC을 이용하여 검증하였다.

• 천문학회지
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• 제43권3호
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• pp.65-74
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• 2010

We investigate ${\rho}$ Pup using the high resolution spectral observations taken from the VLT archive and observations at a 1.8m-Korean telescope with BOES spectrograph. The atmospheric parameters are determined using the iron-line abundance analysis. We derive an effective temperature value of $T_{eff}=6890{\pm}250K$, surface gravity of log g=$3.28{\pm}0.3$ dex, microturbulent velocity of ${\upsilon}_{micro}=4.1{\pm}0.4km\;s^{-1}$, and the iron abundance of log N=$7.82{\pm}0.15$. The projected rotational velocity of the star is close to ${\upsilon}$ sin i=3.5km $s^{-1}$. Asymmetric line profiles in the observed spectra and variation of this asymmetry with time show that both strong radial pulsation and weak non-radial pulsations are present in ${\rho}$ Pup.

• JSTS:Journal of Semiconductor Technology and Science
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• 제6권3호
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• pp.162-168
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• 2006

To fabricate nanometer scale InGaAs HEMTs, we have successfully developed various novel nano-patterning techniques, including sidewall-gate process and e-beam resist flowing method. The sidewall-gate process was developed to lessen the final line length, by means of the sequential procedure of dielectric re-deposition and etch-back. The e-beam resist flowing was effective to obtain fine line length, simply by applying thermal excitation to the semiconductor so that the achievable final line could be reduced by the dimension of the laterally migrated e-beam resist profile. Applying these methods to the device fabrication, we were able to succeed in making 30nm $In_{0.7}Ga_{0.3}As$ HEMTs with excellent $f_T$ of 426GHz. Based on nanometer scale InGaAs HEMT technology, several high performance millimeter-wave integrated circuits have been successfully fabricated, including 77GHz MMIC chipsets for automotive radar application.

• 대한기계학회논문집B
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• 제24권4호
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• pp.533-542
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• 2000

Analytical experiments to determine the line-of-sight temperature distribution is conducted by using spectral radiation intensities. For this study, fourteen narrow bands of $25cm^{-1}$ interval in $CO_2\;4.3{\mu}m$ band ($2,050cm^{-1}$ to $2375cm^{-1}$) are selected. The applied system is a one-dimensional gas slab filled with 100% $CO_2$ gas at 1 atm. Two types of temperature profile are tested; parabolic and boundary layer types. Three kinds of radiation calculation are used in the iteration procedure for the temperature inversion; LBL(Line by Line), SNB(Statistical Narrow Band) and WNB(WSGGM. based Narrow Band) models. The LBL solution shows perfect agreement while some error of temperature prediction is caused by radiation modeling error when using SNB and WNB models. The inversion result shows that the WNB model may be used more accurately in spectral remote sensing techniques than the traditional SNB model.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권5호
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• pp.511-515
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• 2013

A Monte Carlo (MC) simulation study has been done in order to investigate the effects of line-edge-roughness (LER) induced by either 1P1E (single-patterning and single-etching) or 2P2E (double-patterning and double-etching) on fully-depleted silicon-on-insulator (FDSOI) tri-gate metal-oxide-semiconductor field-effect transistors (MOSFETs). Three parameters for characterizing the LER profile [i.e., root-mean square deviation (${\sigma}$), correlation length (${\zeta}$), and fractal dimension (D)] are extracted from the image-processed scanning electron microscopy (SEM) image for each photolithography method. It is experimentally verified that two parameters (i.e., ${\sigma}$ and D) are almost the same in each case, but the correlation length in the 2P2E case is longer than that in the 1P1E case. The 2P2E-LER-induced $V_TH$ variation in FDSOI tri-gate MOSFETs is smaller than the 1P1E-LER-induced $V_TH$ variation. The total random variation in $V_TH$, however, is very dependent on the other major random variation sources, such as random dopant fluctuation (RDF) and work-function variation (WFV).