• 대한전자공학회논문지SD
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• 제42권10호
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• pp.47-54
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• 2005

본 논문에서는 불완전명세(incompletely-specified)를 가진 상태전이그래프(state transition graph: STG)상에서 리던던트 고장(redundant faults)수를 줄여 테스트를 용이하게 하기 위한 새로운 동기 순차회로의 합성방법을 제안한다. 이 STG 합성법에는 1) 구별전이(distinguishable transition)을 이용하여 무정의상태(undefined states)와 불완전명세된 입력전이를 추가하고, 2) 가능한 한 강연결(strongly-connected)이 되도록 하는 방법을 사용한다. 제안된 방법을 이용하여 MCNC 벤치마크 회로에 대해 실험한 결과, 대부분의 회로에 대해 무해 고장의 수가 현격히 줄어들어 높은 고장검출을 얻었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.202.2-202.2
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• 2013

Ti2O3 is known as a typical Mott insulator with a transition temperature of near $200^{\circ}C$. Unlike VO2, Ti2O3 does not have a structural phase transition near the metal-insulator-transition (MIT) temperature. We investigated the temperature-dependent thermal vibration change using temperature-dependent x-ray absorption fine structure (XAFS) at Ti K-edge in the temperature range of 300~600 K. Ti2O3 powder and films were synthesized using thermal chemical vapor deposition (CVD) at $800{\sim}900^{\circ}C$. X-ray diffraction measurements show a single phased Ti2O3 at room temperature. XAFS confirmed no structural phase transition in the temperature of 300~600 K. A small but distinguishable structural disorder change was observed near the transition temperature. We will discuss the MIT behavior with the change of structural disorder.

• 한국측량학회지
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• 제35권1호
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• pp.23-30
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• 2017

NDVI (Normalized Difference Vegetation Index) plays an important role in surface land cover classification and LST (Land Surface Temperature Extraction). Its characteristics do not full carry the information of the surface cover typically in urban areas even though it is widely used in analyses in urban areas as well as in vegetation. However, abnormal NDVI values are frequently found in urban areas. We, therefore, examined NDVI values on whether NDVI is appropriate for LST and whether there are considerations in NDVI analysis typically in urban areas because NDVI is strongly related to the surface emissivity calculation. For the study, we observed the influence of the surface settings (i.e., geometric shape and color) on NDVI values in urban area and transition features between three land cover types, vegetation, urban materials, and water. Interestingly, there were many abnormal NDVI values systematically derived by the surface settings and they might influence on NDVI and eventually LST. Also, there were distinguishable transitions based on the mixture of three surface materials. A transition scenario was described that there are three transition types of mixture (urban material-vegetation, urban material-water, and vegetation-water) based on the relationship of NDVI and LST even though they are widely distributed.

• Korean Membrane Journal
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• 제8권1호
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• pp.67-73
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• 2006

Transparent materials are well known but preparation of transparent poly 2-hydroxyethyl methacrylate {poly (HEMA)} material by varying solvent is a new one and economically reliable. This material is prepared from hydroxyl based monomer HEMA by radical polymerization using benzoyl peroxide (BPO) as initiator and isobutanol, 2-butanol, 1-butanol, hexane and toluene as a solvent. The reaction temperature, time and stirring speed were set at $70^{\circ}C$, 4 hrs and 150 rpm, respectively. The polymer was characterized for functional group by IR spectroscopy. It was observed that the intensity of band at $1637 cm^{-1}$ a characteristic band of C=C stretching disappeared indicating that it was completely consumed after polymerization. It was observed that swelling percentage increases with increase as time passes but after a certain time a constant swelling percentage is achieved. SEM pictures reveals that poly (HEMA) prepared by different solvent shows pore with a distinguishable void up to several micrometers. The BET surface area, cumulative pore volume and average pore diameter is greater in poly (HEMA) prepared by hexane as a solvent compared to other solvents. Poly (HEMA) prepared by 1-butanol as a solvent shows higher glass transition temperature compared to other solvents. Poly (HEMA) prepared by different solvents shows $90{\sim}94%$ light transmission property from light transmission measurement and looks transparent.

• Nuclear Engineering and Technology
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• 제29권1호
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• pp.45-57
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• 1997

The direct contact condensation phenomenon, which occurs when steam is injected into the subcooled water, has been experimentally investigated. Two plume shapes in the stable condensation regime are found to be conical and ellipsoidal shapes depending on the steam mass flux and the liquid subcooling. Divergent plumes, however, are found when the subcooling is relatively small. The measured expansion ratio of the maximum plume diameter to the injector inner diameter ranges from 1.0 to 2.3. By means of fitting a large amount of measured data, an empirical correlation is obtained to predict the steam plume length as a function of a dimensionless steam mass flux and a driving potential for the condensation process. The average heat transfer coefficient of direct contact condensation has been found to be in the range 1.0~3.5 ㎿/$m^2$.$^{\circ}C$. Present results show that the magnitude of the average condensation heat transfer coefficient depends mainly on the steam mass fin By using dynamic pressure measurements and visual observations, six regimes of direct contact condensation have been identified on a condensation regime map, which are chugging, transition region from chugging to condensation oscillation, condensation oscillation, bubbling condensation oscillation, stable condensation, and interfacial oscillation condensation. The regime boundaries are quite clearly distinguishable except the boundaries of bubbling condensation oscillation and interfacial oscillation condensation.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.291.1-291.1
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• 2013

We examined the temperature-dependent structural and magnetic properties of HgI2 in the temperature range of 300~400 K. HgI2 is a diamagnetic material and can be used for X-ray or γ-ray detectors. DCmagnetization measurements on HgI2 showed that there is a small but distinguishable change in its diamagnetic properties near 375 K. The magnetic property change is not expected because Hg and I are known as nonmagnetic elements. X-ray diffraction (XRD) measurements revealed a structural transition in the temperature of 350~400 K. Temperature-dependent x-ray absorption fine structure (XAFS) demonstrated that the chemical valence states of both Hg and I did not changed in the temperature range of 300~400 K. However, XAFS revealed that the bond-length disorder was slightly increased in the temperature range, particularly, near Hg atoms. The structural changes of HgI2 are likely related to its diamagnetic property change. We will discuss the relation between the diamagnetic properties and local structural properties of HgI2 in detail.

• 전기화학회지
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• 제2권3호
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• pp.144-149
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• 1999

0.2M LiOH전해질 내의 다결정 Ir표면에서 저전위 및 과전위 전착된 수소(UPD H및 OPD H)의 전이와 2구별되는 흡착부위를 위상이동 방법을 이용하여 연구하였다 순방향과 역방향 주사시, 순환 전압전류도에 UPD H 봉우리가 나타난다. 위상이동 변화 또는 Langmuir흡착등온식에 전이영역(-0.80 to -0.95 V vs. SCE)이 나타난다. 전이영역(-0.80 to -0.95 V vs. SCE)에서 수소 흡착평형상수(K)는 $7.9\tiems10^{-2}$에서 $1.5\times10^{-4}$또는 $1.5\times10^{-4}$에서 $7.9\times10^{-2}$로 전이한다. 마찬가지로, 수소 흡착표준자유에너지$({\Delta}G_{ads})$도 6.3kJ/mol에서 21.8kJ/mol 또는 21.8kJ/mol에서 6.3kJ/mol로 전이한다. 다결정 Ir표면에서 UPD H와 OPD H는 구별이 가능한 2종류의 전착된 수소같이 작용한다. UPD H봉우리와 전이영역은 다결정 Ir 표면에서 UPD H와 OPD H의 2 구별되는 흡착부위에 기인한다.

• 전기화학회지
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• 제2권4호
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• pp.213-217
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• 1999

다결정 Pt/0.2 M LiOH수성 전해질 계면에서 두 구별되는 수소 흡착부위의 전기화학적 특성을 위상이동 방법을 이용하여 연구하였다. 순방향과 역방향 주사시, 순환 전압전류도에 UPD H 봉우리가 나타난다. 위상이동 변화 또는 Langmuir 흡착등온식에 전이영역(-0.66 to -0.96 V vs. SCE)이 나타난다 전이영역(-0.66 to -0.96 V vs. SCE)에서 수소 흡착평형상수(K)는 18.5에서 $4.0\times10^{-5}$ 또는 $4.0\times10^{-5}$에서 18.5로 전이한다 마찬가지로, 수소 흡착표준자유에너지$({\Delta}G_{ads})$도 -7.2 kJ/mol에서 25.1kJ/mol또는 25.1 kJ/mol에서 -7.2 kJ/mol로 전이한다. 다결정 Pt표면에서 UPD H와 OPD H는 구별이 가능한 두 종류의 전착된 수소 같이 작용한다. 발열반응이 UPD H 영역에서 나타난다. UPD H 봉우리와 전이영역은 다결정 Pt 표면에서 UPD H와 OPD 보의 두 구별되는 흡착부위에 기인한다.

• 암석학회지
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• 제7권1호
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• pp.27-36
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• 1998

대구-경주지역에 분포하는 백아기 화산암류는 하부로부터 학봉현무암질암류, 채약산현무암지람류 및 유천층군의 주사산안산암질암류와 운문사유문암질암류 등으로 구성된다. 학봉현무암질암류는 신라역 암층을 덮고 있으며 이와 그 상위에 높이는 채약산현무암질암류 사아이네느 두께 앞 2400 m에 달하는 함안층, 반야월층 및 송내동층의 두터운 퇴적암층이 높여 있고 채약산현무암질암류와 주사산암산암질암류 사이에는 두께 300 m 가량의 건천리층이 개재되어 있어 이들 화산암류는 상당한 시간적, 위치적 공간을 사이에 두고 일어난 화산활동의 산물인 만큼 이들은 각기 상이한 암석학적 특성을 지니고 있음이 들어난다. 주성분 지호학적 특성에 있어서 학봉현무암질암류와 채약산현무암질암류는 알카리계열의 특성을 보이며 주사산안 산암질암류는 포함지역의 제 3기 현무암/안산암류와 흡사하게 칼크알카리게열에 속한다. 반면 Nb, Y, Zr, Ti 등 저변성작용에서도 이동성이 매우 적은 원소에 의하면 학봉현무암질암류는 알카리에서 칼크알카리계열에 속하는 모마그마형을 보이나 스필라이트질인 채약산현무암질암류는 주사산암산암질암류와 유사한 칼크알카리게열의 모마크마로 부터 유래했음을 보여준다. 이러한 모마그마와 그 산물의 상이성은 마그마의 상승과정을 통한 지각물질에 의한 혼염작용 혹은 분출한 다음에 있었던 변질작용등에 의한 것으로 해석될 수도 있을 것이다.