• Journal of Environmental Science International
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• v.3 no.1
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• pp.17-29
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• 1994

An one dimensional atmosphere-vegetation interaction model is developed to discuss of the effect of vegetation on heat flux in mesoscale planetary boundary layer. The canopy model was a coupled system of three balance equations of energy, moisture at ground surface and energy state of canopy with three independent variables of $T_f$(foliage temperature), $T_g$(ground temperature) and $q_g$(ground specific humidity). The model was verified by comparative study with OSUID(Oregon State University One Dimensional Model) proved in HYPEX-MOBHLY experiment. As the result, both vegetation and soil characteristics can be emphasized as an important factor iii the analysis of heat flux in the boundary layer. From the numerical experiments, following heat flux characteristics are clearly founded simulation. The larger shielding factor(vegetation) increase of $T_f$ while decrease $T_g$. because vegetation cut solar radiation to ground. Vegetation, the increase of roughness and resistance, increase of sensible heat flux in foliage while decrease the latent heat flux in the foliage.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.31.4-32
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• 2008

The microwave instruments are used many areas of the space remote sensing and space science applications. The imaging radar of synthetic aperture radar (SAR) is well known microwave radar sensor for earth surface and ocean research. Unlike radar, microwave radiometer is passive instrument and it measures the emission energy of target, i.e. brightness temperature BT, from earth surface and atmosphere. From measured BT, the geophysical data like cloud liquid water, water vapor, sea surface temperature, surface permittivity can be retrieved. In this paper, the radiometer characteristics, system configuration and principle of BT measurement are described. Also the radiometer instruments TRMM, GPM, SMOS for earth climate, and ocean salinity research are introduce. As first korean microwave payload on STSAT-2, the DREAM (Dual-channels Radiometer for Earth and Atmosphere Monitoring) is described the mission, system configuration and operation plan for life time of two years. The main issues of DREAM unlike other spaceborne radiometers, will be addressed. The calibration is the one of main issues of DREAM mission and how it contribute on the space borne radiometer. In conclusion, the radiometer instrument to space science application will be considered.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.729-731
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• 1998

Surface passivation using glass powders results in good reliability for high voltage silicon power devices. In this paper, Zinc borosilicate glass was prepared for the purpose of passivating, and a deposition technique of glass films on the silicon surface by electrophoresis in which acetone is used as a suspension medium and a measurement technique of C-V curve has been investigated. Properties were compared using SEM, XRD, C-V Curve as a function of firing condition, temperature and atmosphere were investigated. Under 100V applied, 1 minute, $700^{\circ}C$ firing temperature, and $O_2$ atmosphere, I can get the fine films $5.8{\mu}m$ thickness with Zinc borosilicate glass. As a result of investigation of glass films, it has been found that pre-firing and annealing play an important role to achieve uniform, fine, reliable glass deposition films and Glass/Silicon interlace.

• Proceedings of the KSRS Conference
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• v.1
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• pp.312-315
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• 2006

Radio occultation technique has been used in planetary science to obtain reliable and accurate temperature profiles of the other planets' atmosphere for decades. It relies on the fact that radio waves are bent and delayed due to the gradient of atmospheric refractivity along-ray-path. With the advent of Global Positioning System (GPS), it becomes possible to retrieve the refractivity and temperature profiles of the Earth's atmosphere from the occultation data. We have developed a retrieval algorithm and compared the results of our algorithm with the data of CHAMP to verify the accuracy of our algorithm is good enough. In our algorithm, there are some smoothing steps when retrieving. We analysis the data of FORMOSAT-3 and compare the results with and without smoothing and the results of TACC to see is there any phenomenon deleted after smoothing.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.714-718
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• 2003

Usually for the commercial preparation of barium titanate films or ceramics the reaction atmosphere must be preferably in air. However, normally air is not used because it contains carbon dioxide, which can easily react with barium to form the undesired product barium carbonate, leading to unwanted second-phase formation in the (mal stages of the process. In the present work a series of perovskite barium titanate films was prepared by the sol-gel method, using a metal alkoxide solutions in the electrophoretic deposition (EPD). The influence of several process parameters, like sintering temperature of sol preparation before EPD and heat-treatment temperature and non-oxidized atmosphere, on the film properties is described.

• Journal of the Korean Ceramic Society
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• v.26 no.1
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• pp.31-36
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• 1989

In order to synthesize AlN-polytypes from AlN-SiO2-Al2O3 system, composition A (AlN/SiO2/Al2O3=1/0.3/0.05, mole ratio) and composition B(AlN-SiO2-Al2O3=1/0.2/0.05, mole ratio) were used. AlN-polytypes were produced by nitriding the mixture at 175$0^{\circ}C$~190$0^{\circ}C$ under N2 atmosphere. For lower reaction temperature, 15R phase was produced and in the case of higher reaction temperature, AlN phase was only produced. As each composition was heated at 185$0^{\circ}C$ in N2 atmosphere, produced main phases were 15R phase for composition A and 21R phase for composition B respectively. The fracture surfaces of produced reactants showed porous skeleton structure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.135-141
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• 2000

The physical, electrical and piezoresitive characteristics of CrN(chromiun nitride) thin-films on silicon substrates have been investigated for use as strain gauges. The thin-film depositions have been carried out by OC reactive magnetron sputtering in an argon-nitrogen atmosphere(Ar-(5~25 %)$N_2$). The deposited CrN thin-films with thickness of $3500{\AA}$ and annealing conditions($300^{\circ}C$, 48 hr) in Ar-10 % $N_2$ deposition atmosphere have been selected as the ideal piezoresistive material for the strain gauges. Under optimum conditions, the CrN thin-films for the strain gauges is obtained a high electrical resistivity, $\rho=1147.65\;{\mu}{\Omega}cm$, a low temperature coefficient of resistance, TCR=-186 ppm/$^{\circ}C$ and a high temporal stability with a good longitudinal gauge factor, GF=11.17.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.565-568
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• 2006

This paper achieved dynamic characteristics with test to use solenoid valve for flight model that have present. Designed pressure control virtual system which PWM solenoid valve to use test result. Examination compared solenoid valve dynamic characteristics in atmosphere and cryogenic fluid and presented technique and valuation method that measured upstream and down stream pressure of solenoid valve, as well as, temperature, excitation voltage etc. These test results could confirm solenoid valve response time and maximum using frequency characteristic at use in atmosphere and cryogenic temperature and this derived design variables pressure control system from those bases.

• Bulletin of the Korean Chemical Society
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• v.25 no.5
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• pp.620-624
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• 2004

Optical emission studies were performed to investigate thermal and dynamical properties of a plume produced by laser ablation of a graphite target in a nitrogen atmosphere. Experimental spectra of $C_2(d^3{\Pi}_g{\to}a^3{\Pi}_u$, ${\Delta}_V$=1) and CN ($B^2{\Sigma}^+{\to}X^2{\Sigma}^+,{\Delta}_V=0)$ were simulated to obtain the vibrational and rotational temperatures of the electronically excited species at various laser fluences and distances from the target. The spectroscopic temperatures of both molecules were found to be nearly independent of the laser fluence. The temperature of CN molecules was peaked in the middle of the plume while that of $C_2$decreased with increase in the distance. At a given distance, the temperature of CN molecules was clearly higher than that of $C_2$.

• Transactions of Materials Processing
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• v.26 no.3
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• pp.150-155
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• 2017

To obtain the Goss texture, {110}<001>, IF steel sheets were asymmetrically rolled by 50-89% reduction in the thickness at room temperature and subsequently annealed at 200, 900, and $1200^{\circ}C$ in a box furnace under air atmosphere. The asymmetrically rolled specimens and annealed specimens show well-developed Goss texture, {110}<001>. After the IF steel sheets were asymmetrically rolled at room temperature and subsequently annealed at $900^{\circ}C$ for 1 h in a box furnace under air atmosphere, the intensity of the Goss texture, {110}<001> was high in the IF steel sheets.