• 천문학회보
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• 제39권2호
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• pp.76.1-76.1
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• 2014

We present near-infrared spectroscopic and photometric observations of the nova V2468 Cyg taken from 2008 March 14 till 2008 November 11 following its outburst on 2008 March 7. The JHK spectra of the nova have been taken from the Mount Abu Infrared Observatory using the Near-Infrared Imager/Spectrometer. The early spectra are dominated by strong H I lines from the Brackett and Paschen series, Fe II, O I and C I lines, typical of Fe II type novae but after 46 days from outburst there is significant reduction in the strength of the C I lines and the spectra are dominated by He I lines. The FWHM of the Pa-beta and Br-gamma lines change from 2200-2300 km s-1 to 1700-1800 km s-1 after 12 days from outburst. Three additional small amplitude outbursts are seen near 110, 185 and 240 days in the V band light curve after the discovery. The upper limit for the ejecta mass for V2468 Cyg is estimated to be $5.2{\times}10-6Msun$.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권2호
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• pp.86-91
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• 2004

PV power generation, which directly converts solar radiation into electricity, contains numerous significant advantages. It is inexhaustible and pollution-free, silent, contains no rotating parts, and has size-independent electricity conversion efficiency. The positive environmental effect of photovoltaics is that it replaces the more polluting methods of electricity generation or that it provides electricity where none was available before. This paper highlights a novel simple method to abstract the entire parameters of the solar cell. In development, design and operation of PV power generation systems, a technique for constructing V-I curves under different levels of solar irradiance and cell temperature conditions using basic characteristic values of the PV module is required. Everyone who has performed manual acquisition and analysis of solar cell I versus V data would agree that the job is tedious and time-consuming. A better alternative is to use an automated curve tracer to print out the I versus V curves and compute the four major parameters; $V_{oc}$, $I_{sc}$, FF, and . Generally, the V-I curve tracer indicates only the commonly used solar cell parameters. However, with the conventional V-I curve tracer it is almost impossible to abstract the more detailed parameters of the solar cell; A, $R_{s}$ and $R_{sh}$ , which satisfies the user, who aims at the analysis of the development of the PV power generation system, that being advanced simulation. In this paper, the proposed method provides us with satisfactory results to enable us to abstract the detailed parameters of the solar cell; A, $R_s$ and $R_{sh}$.>.

• Biomolecules & Therapeutics
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• 제9권2호
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• pp.96-103
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• 2001

These studies were investigated about influence of SKP 450, a $K^{+}$ channel opener, on the pressor actions induced by norepinephrine, angiotensin II and carotid artery occlusion in rats. Before these studies, effect of SKP 450 itself on blood pressure was examinated. SKP 450 produced the depressor action in proportionaly to dose of 0.3, 1.0 and 3.0 $\mu$g/kg given intravenously and this depressor action was weakened by pretreatment of glibenclamide, a $K^{+}$ channel blocker. The pressor action induced by norepinephrine, an alpha-adrenergic agonist, was blocked 1 hr after administation of SKP 450 in a dose of 3.0 $\mu\textrm{g}$/kg, i.v. and directly after in a dose of 6.0 $\mu\textrm{g}$/kg, i.v.. The pressor action induced by angiotensin II was blocked immediatly after treatment of SKP 450 in a dose of 3.0 $\mu\textrm{g}$/kg, i.v.. The pressor action caused by carotid artery occlusion was not affected by SKP 450 of 3.0 $\mu\textrm{g}$/kg, i.v., whereas markedly blocked by SKP 450 of 6.0 $\mu\textrm{g}$/㎦, i.v.. The potentiated-pressor actions of norepinephrine and angiotensin II by pretreatment of chlorisondamine, a autonomic ganglionic blocking agent, were also blocked by administration of SKP 450 in a dose of 6.0 $\mu\textrm{g}$/kg, i.v.. The weakened-pressor action of carotid artery occlusion by pretreatment of chlorisondamine was more weakened by SKP 450 6.0 $\mu\textrm{g}$/kg, i.v.. The results suggest that hyperpolarization formed through $K^{+}$ channel opening in cell membrane inhibits the pressor action induced norepinephrine ; angiotensin II ; and carotid artery occlusion.usion.

• 센서학회지
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• 제6권3호
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• pp.194-199
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• 1997

자기센서가 전압이나 전류의 형태 그대로 출력되는 경우에 발생되는 잡음 유입 및 전압 손실 문제를 개선하기 위하여 소자부는 CMOS공정을 이용하여, 포화영역에서 동작하는 2 drain의 MAGFET을 설계 제작하고, 연산증폭기를 이용한 I-V변환회로, VCO(Voltage Controlled Oscillator)를 만들고 Schmitt trigger에 의한 주파수(Pulse) 변환회로의 시스템부를 하이브릿드 IC로 구성하여 packaging했다. 이 때 자기센서 절대감도는 1.9 V/T, 적감도는 $3.2{\times}10^{4}\;V/A{\cdot}T$ 이었으며 190 kHz/T의 안정된 출력 주파수 특성을 얻을 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 제6회 학술대회 논문집 일렉트렛트 및 응용기술연구회
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• pp.52-56
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• 2004

The movement of electron in the semiconductor-gap-semiconductor was observed by the variation of V-I characteristic as a distance two ZnO(1010) single crystals. When the resistance between two crystals was $10^2{\sim}10^4{\Omega}$, V-I characteristics had the pattern of the field emission or ohmic contact. On the other hand, when the resistance was larger than $10^7{\Omega}$ by increasing the distance between two crystals, the effect of surface barrier was prominent. This result leads to the conclusion that both the field emission (or ohmic contact) and the surface barrier effect including the tunneling have the influence on V-I characteristics of mechanically contacted crystals.

• 반도체디스플레이기술학회지
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• 제17권2호
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• pp.12-15
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• 2018

InSb (III-V compound semiconductor) is used for photodiode to detect the mid-wavelength infrared radiation. Generally the quantum efficiency of InSb IR FPAs(Focal Plane Arrays) is known to be determined by thickness of InSb and transmittance of anti-reflection coating layer. In this study, we confirmed that the C-V characteristics of detector array affects the quantum efficiency of the InSb IR FPAs. We fabricated the IR FPAs with various $V_{fb}$(flat band voltage) values and confirmed the tendency between the $V_{fb}$ value and quantum efficiency of the IR FPAs.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.158-158
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• 2003

수평 전기로에서 CuGaTe2 다결정을 합성하여 HWE 방법으로 CuGaTe2 단결정 박막을 반절연성 GaAs(100) 위에 성장하였다. CuGaTe2 단결정 박막은 증발원과 기판의 온도를 각각 67$0^{\circ}C$, 41$0^{\circ}C$로 성장하였다. 이때 단결정 박막의 결정성이 10K에서 측정한 광발광 스펙트럼은 954.5nm (1.2989eV) 근처에서 exciton emission 스펙트럼이 가장 강하게 나타났으며, 또한 이중결정 X-선 요동곡선(DCRC)의 반폭치(FWHM)도 139arcsec로 가장 작게 측정되어 최적 성장 조건임을 알 수 있었다. Hall 효과는 van der Paw방법에 의해 측정되었으며, 온도에 의존하는 운반자 농도와 이동도는 293K에서 각각 8.72$\times$$10^{23}$개/㎥, 3.42$\times$$10^{-2}$$m^2$/V.s였다. 상온에서 CuGaTe2 단결정 박막의 광흡수 특성으로부터 에너지 띠간격이 1.22 eV였다 Band edge에 해당하는 광전도도peak의 온도 의존성은 Varshni 관계식으로 설명되었으며, Varshni 관계식의 상수값은 Eg(0) = 1.3982 eV, $\alpha$= 4.27$\times$$10^{-4}$ eV/K, $\beta$= 265.5 K로 주어졌다. CuGaTe2 단결정 박막의 광전류 단파장대 봉우리들로부터 10K에서 측정된 $\Delta$cr (crystal Field splitting)은 0.0791eV, $\Delta$s.o (spin orbit coupling)는 0.2463eV였다. 10K에서 광발광 봉우리의 919.8nm (1.3479eV)는 free exciton(Ex), 954.5nm (1.2989eV)는 donor-bound exciton 인 I2(DO,X)와 959.5nm (1.2921eV)는 acceptor-bound exciton 인 I1(AO,X) 이고, 964.6nm(1.2853eV)는 donor-acceptor pair(DAP) 발광, 1341.9nm (0.9239eV)는 self activated(SA)에 기인하는 광발광 봉우리로 고찰되었다.

• 대한수학회지
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• 제45권6호
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• pp.1613-1622
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• 2008

Let G be a graph with vertex set V(G) and edge set E(G), and let g, f be two nonnegative integer-valued functions defined on V(G) such that $g(x)\;{\leq}\;f(x)$ for every vertex x of V(G). We use $d_G(x)$ to denote the degree of a vertex x of G. A (g, f)-factor of G is a spanning subgraph F of G such that $g(x)\;{\leq}\;d_F(x)\;{\leq}\;f(x)$ for every vertex x of V(F). In particular, G is called a (g, f)-graph if G itself is a (g, f)-factor. A (g, f)-factorization of G is a partition of E(G) into edge-disjoint (g, f)-factors. Let F = {$F_1$, $F_2$, ..., $F_m$} be a factorization of G and H be a subgraph of G with mr edges. If $F_i$, $1\;{\leq}\;i\;{\leq}\;m$, has exactly r edges in common with H, we say that F is r-orthogonal to H. If for any partition {$A_1$, $A_2$, ..., $A_m$} of E(H) with $|A_i|=r$ there is a (g, f)-factorization F = {$F_1$, $F_2$, ..., $F_m$} of G such that $A_i\;{\subseteq}E(F_i)$, $1\;{\leq}\;i\;{\leq}\;m$, then we say that G has (g, f)-factorizations randomly r-orthogonal to H. In this paper it is proved that every (0, mf - (m - 1)r)-graph has (0, f)-factorizations randomly r-orthogonal to any given subgraph with mr edges if $f(x)\;{\geq}\;3r\;-\;1$ for any $x\;{\in}\;V(G)$.

• 한국결정성장학회지
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• 제7권3호
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• pp.487-493
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• 1997

SiC(4H) 결정에 Ti을 열증착하여 Ti/SiC(4H) 쇼트키(Schottky) 장벽 다이오드를 만들었다. SiC(4H)의 주개농도(donor concentration)는 전기용량-전압(C-V) 측정으로부터 $2.0{\times}10^{15}{\textrm}{cm}^{-3}$이었으며, 내부전위(built-in potential)는 0.65 V이었다. 전류-전압(I-V) 특성으로 부터 다이오드의 이상계수(ideally factor)는 1.07이었으며, 역방향 항복전장(breakdown field)은 약 $1.7{\times}10^3V/{\textrm}{cm}$이었다. 상온에서 $140^{\circ}C$까지 온도변화에 따라 측정된 포화전류로 부터 구한 전위장벽(potential barrier)은 0.91 V이었는데, 이는 C-V 특성으로 부터 구한 전위장벽과 거의 같았다.

• 제어로봇시스템학회지
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• 제18권2호
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• pp.21-29
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• 2012

최근 자동차 연구개발에 있어 내연기관을 대체하는 친환경 자동차기술과 더불어 무인자동차, 자율주행기술이 많은 부분에서 시도되고 실현되어가고 있다. 지능형 자동차라는 개념에서 적용되었던 운전자안전보조시스템, 편의지원과 사고경감 시스템 등이 하나로 통합되어 무인자동차 기술로 발전하고 있다. 또 차량에 고가의 센서를 장착하여 주변환경이나 운전자를 모니터링하는 방식에서 IT 융합기술을 이용한 네트워크기술 (V2I, V2V, V2N & V2X)을 접목시키는 방안을 통하여 개개의 차량은 물론 교통체계의 전체적인 변화를 추구하고 있다. 이러한 첨단차량기술은 새로운 교통문화(차량공유시스템, 군집주행)의 개발과 또다른 교통체계의 연구로 확장되어가고 있다.