• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.208-213
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• 2011

In the former study, it is obtained that thermal storage effect of the apartment structure is the disadvantage to maintain comfort indoor thermal environment. However, because the thermal storage effect can be changed of its aspect in heating season, field measurement at the same apartment with the measurement in summer season was conducted in winter season. As results, thermal storage effect of apartment structure was the disadvantage in winter season, too.

• Animal cells and systems
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• v.10 no.4
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• pp.183-189
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• 2006

The fine structural characteristics of the antennal sensory organs of a female millipede, Orthomorphella pekuensis, were observed with field emission scanning electron microscopy. On the surface of the antenna, four basic types of sensory receptor with the function of either mechanical or olfactory reception are identified in this female millipede. Of these, chaetiform sensilla (CS) and trichoid sensilla (TS) are related to mechanical reception, and four large apical cone sensilla (AS) and three subtypes of basiconic sensilla ($BS_1,\;BS_2,\;BS_3$) are likely to function in olfactory reception, as these receptors have porous structure commonly. Although this millipede also possess a number of primary or secondary sexual characters to improve the efficiency of reproduction, we could not observe their prominent sexually dimorphic characters in the antennal sensilla with the exception of minor structural and numerical differences.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.47.2-47.2
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• 2011

Gravitational waves from the pulsar glitch can be detected by next generation gravitational wave observatories. We investigate characteristics of the modes that can emit the gravitational waves excited by three different types of perturbations satisfying conservation of total rest mass and angular momentum. These perturbations mimic the pulsar glitch theories i.e., change of moment of inertia due to the star quakes or angular momentum transfer by vortex unpinning at crust-core interface. We carry out numerical hydrodynamic simulations using the pseudo-Newtonian method which makes weak field approximation for the dynamics, but taking all forms of energies into account to compute the Newtonian potential. Unlike other works, we found that the first and second strongest modes that give gravitational waves are $^2p_1$ and $H_1$ rather than$^2f$. We also found that vortex unpinning model excites the inertial mode in quadrupole moment quite effectively. The inertial mode may evolve into the non-axisymmetric r-mode.

• Transactions on Electrical and Electronic Materials
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• v.17 no.1
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• pp.41-45
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• 2016

The Cs₃Sb photocathode was formed by non-vacuum process technology and successive in-situ photocathode vacuum device fabrication carried out in a process chamber. Performance testing of the device was followed. Light emission from the devices was induced by photoemitted electrons, which were accelerated by an anode electric field that was shielded from the photoemitter surface. The luminescent characteristics of the devices were investigated by measuring the optical parameters as functions of the applied anode voltages. The results showed that this approach could produce a more easily directed and controlled stream of light. These features make these devices suitable for a variety of planar lighting applications.

• Transactions on Electrical and Electronic Materials
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• v.13 no.3
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• pp.121-124
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• 2012

Olivine type $LiFePO_4$ cathode material was synthesized by solid-state reaction method including one-step heat treatment. To improve the electrochemical characteristics, graphite nanofiber (GNF) was added into $LiFePO_4$ cathode material. The structure and morphological performance of $LiFePO_4$ were investigated by X-ray diffraction (XRD); and a field emission-scanning electron microscope (FE-SEM). The synthesized $LiFePO_4$ has an olivine structure with no impurity, and the average particle size of $LiFePO_4$ is about 200~300 nm. With graphite nanofiber added, the discharge capacity increased from 113.43 mAh/g to 155.63 mAh/g at a current density of 0.1 $mA/cm^2$. The resistance was also significantly decreased by the added graphite nanofiber.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.384-385
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• 2007

탄소나노튜브의 전계방출 특성은 그 길이에 많은 영향을 받으며 길이가 균질 할수록 전계방출에 참여하는 탄소나노튜브의 수가 증가하여 전자방출의 균일도가 향상되고 수명도 증가할 것으로 기대되고 있다. 이 논문에서는 탄소나노튜브의 길이를 인위적으로 제어하여 균질하게 하기 위해 오존을 이용하여 길이가 긴 탄소나노튜브만 선택적으로 제거하는 방법을 사용하였다. 오존에 의해 처리한 시편은 전에 비해 높은 균일도를 나타내고 수명도 약 4배가량 크게 향상되었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.935-938
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• 2004

In this work, carbon nanofibers have synthesized a low temperature using DC Ar Plasma and Fe-Phthalocyanine, and a characteristic difference of the synthesized CNF according to the location of the substrate was investigated. the density of CNFs synthesized on the position (a) were higher than that synthesized on the position (b) [See the Fig. 1]. Also, the length of CNFs was different. In the shape, CNFs with screw and straight line shape were synthesized in the position (a), but only CNFs with straight line shape were synthesized in the position (b). The difference have an important effect on the field emission characteristics.

• Journal of Integrative Natural Science
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• v.4 no.1
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• pp.7-10
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• 2011

Various types of smart dust based on photonic crystal exhibiting unique reflectivity were successfully obtained by an electrochemical etching of silicon wafer using square wave currents. Smart dust containing Bragg structure obtained from the sonication of DBR porous silicon film in solution retained its optical reflectivity. Field emission scanning electron micrograph (FE-SEM) was used to measure the size of optically encoded smart dust and its size can be tuned from few hundred nanometers to few microns depending on the duration of sonication. Optical characteristics of smart dust were used to investigate a possible applications such as chemical sensors.

• Journal of Integrative Natural Science
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• v.7 no.1
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• pp.1-4
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• 2014

Distributed Bragg reflector porous silicon of different characteristics were formed to determine their optical constants in the visible wavelength range using a periodic square wave current between low and high current densities. The surface and cross-sectional SEM images of distributed Bragg reflector porous silicon were obtained using a cold field emission scanning electron microscope. The surface image of distributed Bragg reflector porous silicon indicates that the distributions of pores are even. The cross-sectional image illustrates that the multilayer of distributed Bragg reflector porous silicon exhibits a depth of few microns and applying of square current density during the etching process results two distinct refractive indices in the contrast. Distributed Bragg reflector porous silicon exhibited a porosity depth profile that related directly to the current-time profile used in etch. Its free-standing film was obtained by applying an electro-polishing current.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.284-285
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• 2003

Significant research interest in the growth and characterization of $Y_2$O$_3$：Eu$^{3+}$ thin films has been shown over the last few years because of the promise for applications of display devices. Although an Eu-doped oxysulfide (Eu： $Y_2$O$_2$S) which has an efficiency of 13％ has been used for a traditional cathode ray tube (CRT) red phosphor, the sulfide system is known to degrade rapidly under the high current densities needed for field-emission display (FED) technology. (omitted)d)