• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.264.2-264.2
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• 2013

Molecular layer deposition (MLD) is sequential, self-limiting surface reaction to form conformal and ultrathin polymer film. This technique generally uses bifunctional precursors for stepwise sequential surface reaction and entirely organic polymer films. Also, in comparison with solution-based technique, because MLD is vapor-phase deposition based on ALD, it allows epitaxial growth of molecular layer on substrate and is especially good for surface reaction or coating of nanostructure such as nanopore, nanochannel, nanwire array and so on. In this study, polyurea film that consisted of phenylenediisocyanate and phenylenediamine was formed by MLD technique. In situ Fourier Transform Infrared (FTIR) measurement on high surface area SiO2 substrate was used to monitor the growth of polyurethane and polyurea film. Also, to investigate orientation of chemical bonding formed polymer film, plan-polarized grazing angle FTIR spectroscopy was used and it showed epitaxial growth and uniform orientation of chemical bones of polyurea films.

• The Journal of the Acoustical Society of Korea
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• 제17권3E호
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• pp.27-34
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• 1998

The validity of the image model is investigated both analytically and experimentally in a half space with an infinite single reflecting surface present. This paper exploits the Sommerfeld integral that represents the exact solution for the reflected field in the half space. The solution is shown to be obtained by direct numerical integration which yields more accurate and stable results. The predicted results from the image model are compared to those from the direct numerical integration of the Sommerfeld integral. It is also experimentally demonstrated that the image model gives acceptably accurate results. It is of significance that this paper reveals analytical and experimental validation of using the image model except near-grazing incidence.

• The Korean Journal of Ecology
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• 제24권6호
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• pp.365-370
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• 2001

The vegetation of the Khogno Khan Natural Reserve of the central Mongolia was studied in terms of the Zurich-Montpellier School's method. Twenty plant communities were identified from the three different landscape types such as mountain areas(63%), plains(32%), and wetlands(5%). Actual vegetation map using five vegetation domains was accomplished in order to understand the spatial distribution of regional vegetation. Steppe vegetation of 88% vegetation cover to the whole area is representative, which is composed of a matrix of landscape. The birch-aspen forests and the elm bush forests are relics as a patch distribution. It is recognized that the whole territory of protected area be under the effects of severe grazing from the phytosociological viewpoint.

• 천문학회보
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• 제37권1호
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• pp.100.1-100.1
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• 2012

Lunar limb profiles are needed for analyses of lunar occultations and solar eclipses. The lunar limb profile data by C.B. Watts (1963) have been used for such analyses, but it has been found that there are many kinds of errors in the data by Watts, which seriously affected the results obtained from the analyses of the observations. Recently very precise lunar topographic data were obtained by the Japanese lunar explorer Kaguya and NASA's Lunar Reconnaissance Orbiter. I obtained lunar limb profiles for any lunar librations from them. I will show how well the lunar limb profiles fit to observed ones from lunar grazing occultations. By combining the accurate lunar limb profiles with observations of lunar occultations we can detect errors in the Hipparcos stellar reference frame. By analyzing Baily's beads timing observations of past total and annular solar eclipses using the accurate lunar limb profiles we will be able to detect solar diameter variations.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.877-880
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• 1999

A rigorous formulation is suggested〔l,2,3〕 in solving the scattering of plane waves by a dielectric wedge. Correcting surface currents are expanded in a Neumann series of fractional orders to meet the edge condition of static limit〔4〕. For the better converging series, the modified Neumann series satisfying the static limit edge condition and the radiation condition are suggested here for the surface currents having two different wave numbers of air and dielectric〔4〕. This representation gives accurate solutions over the whole region including the grazing incidence of the plane waves upon the dielectric wedge of large permittivities.

• Macromolecular Research
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• 제13권6호
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• pp.506-513
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• 2005

We review the recent SAXS activity on the 1.5-GeV electron storage ring at the National Synchrotron Radiation Research Center (NSRRC). Typical measurements featuring in grazing incident SAXS for soft materials are illustrated. Complex measurements using simultaneous SAXS/DSC and SAXSIWAXS for the correlations between the crystallization and mesoscale ordering in a polymer blend and a polypeptide-block-polypseudorotaxane diblock copolymer are presented. We also introduce a dedicated SAXS beamline which is planned at NSRRC.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 동계학술발표대회 논문집
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• pp.500-505
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• 2005

This paper introduces an experimental study for the noise characteristics and reduction of a ventilating fan system. For the purpose of noise reduction of it, an absorptive duct silencer filled with a glass fiber has been conventionally utilized. However, a glass fiber has some disadvantages like hygiene and secondary pollution problems. In order to overcome these problems, in this paper, a perforated duct silencer has been applied to the ventilating fan system. For the designing of a perforated duct silencer, the transmission losses for various perforated panel systems are measured and compared with their sound absorption performances.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 춘계학술대회 논문집 디스플레이 광소자 분야
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• pp.164-168
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• 2005

We report high performance poly (3-hexylthiophene) organic field-effect transistors fabricated on a plastic substrate. The polymer active channel layer was directly printed by the rubber stamp printing method with a pre-patterned elastomer stamp. As a result. organic transistors having average field-effect mobility of 0.079 $cm^2/Vs$ and on/off ratio of $10^4{\sim}10^5$ were realized on a plastic substrate. Also, through the investigation of the molecular ordering of rubber-stamp-printed poly (3-hexylthiophene) films using synchrotron grazing-incidence X-ray diffraction measurements, the films were found to have edge-on structure which is favorable in realizing high performance organic transistors.

• 한국진공학회지
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• 제8권3A호
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• pp.213-217
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• 1999

Fe/MnO multilayers with different bilayer thicknesses were grown by pulsed laser deposition method. Grazing incidence X-ray reflectivity results showed obvious multilayer Bragg peaks implying highly layered samples and, through their analysis, some structural parameters were quantiatively estimated. From the X-ray diffraction peak corresponding to MnO(111), Mn-oxide turned out to be dominantly MnO. To characterize the magnetic properties of $Mn^{+2}$, XMCD were carried out. Magnetic moments of MnO near interfaces were ordered in the opposite direction to those of Fe.

• 한국자원식물학회지
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• 제36권3호
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• pp.219-224
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• 2023

Melilotus dentatus (Waldst. & Kit.) Desf. is an invasive plant native to Europe, Russia, Uzbekistan, Mongolia and China. It was introduced to North America to create grazing areas for livestock; its growth has since become uncontrollable. Melilotus dentatus is now found in Namyang-eup, Hwaseong-si, Gyeonggi-do, South Korea as an alien plant. This species is morphologically similar to Melilotus suaveolens Ledeb. and Melilotus officinalis (L.) Lam. M. dentatus differs from other species based on its oblong leaflets, distinct teeth, two ovules, surface of the legume that is minutely reticulate-nerved or smooth, and seeds that are dark green to greenish brown. Here, we have provided a detailed description and photographs of the alien species M. dentatus as well as an updated key to five Melilotus taxa studied, which will help prepare a continuous monitoring and management plan.