• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.3
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• pp.203-209
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• 2015

This paper discusses the effectiveness of using Landsat 8 TIR (Thermal Infrared) band images to improve the accuracy of landuse/landcover classification of urban areas. According to classification results for the study area using diverse band combinations, the classification accuracy using an image fusion process in which the TIR band is added to the visible and near infrared band was improved by 4.0%, compared to that using a band combination that does not consider the TIR band. For urban area landuse/landcover classification in particular, the producer’s accuracy and user’s accuracy values were improved by 10.2% and 3.8%, respectively. When MLC (Maximum Likelihood Classification), which is commonly applied to remote sensing images, was used, the TIR band images helped obtain a higher discriminant analysis in landuse/landcover classification.

• Journal of Radiation Industry
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• v.5 no.3
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• pp.227-230
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• 2011

Pulps were separated from wood chips using an Electron beam irradiation (EBI) treatment without a NaOH-AQ (anthraquinone) treatment for cooking. The methods were based on a hot water treatment after EBI and two-step bleaching processes. Chemical compositions and FT-IR spectroscopy demonstrated that the content of lignin and hemicellulose in the bleached wood pulps treated with various EBI dose decreased with an increase of EBI doses. Specifically, the lignin in the bleached with pulps treated at 600 kGy of EBI dose was almost completely removed. Moreover, TGA analysis showed that a thermal stability increased with increasing the content of cellulose but the lignin decomposed slowly over the wide region.

• Nuclear Engineering and Technology
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• v.51 no.2
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• pp.369-376
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• 2019

A complete solution for a soluble-boron-free (SBF) small modular reactor (SMR) is pursued with a new burnable absorber concept, namely centrally-shielded burnable absorber (CSBA). Neutronic flexibility of the CSBA design has been discussed with fuel assembly (FA) analyses. Major design parameters and goals of the SBF SMR are discussed in view of the reactor core design and three CSBA designs are introduced to achieve both a very low burnup reactivity swing (BRS) and minimal residual reactivity of the CSBA. It is demonstrated that the core achieves a long cycle length (~37 months) and high burnup (~30 GWd/tU), while the BRS is only about 1100 pcm and the radial power distribution is rather flat. This research also introduces a supplementary reactivity control mechanism using stainless steel as mechanical shim (MS) rod to obtain the criticality during normal operation. A further analysis is performed to investigate the local power peaking of the CSBA-loaded FA at MS-rodded condition. Moreover, a simple $B_4C$-based control rod arrangement is proposed to assure a sufficient shutdown margin even at the cold-zero-power condition. All calculations in this neutronic-thermal hydraulic coupled investigation of the 3D SBF SMR core are completed by a two-step Monte Carlo-diffusion hybrid methodology.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.5
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• pp.724-729
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• 2008

Umbilical cord blood has been recently considered an attractive potential alternative as a source of stem cell transplantation to curing diseases such as leukemia, cancers, immune disorders. Normally the stored system of the umbilical cord blood specimen is equipped with a computer-controlled robotic arm that enables the samples to locate the identification places in liquid nitrogen tank at regulated temperature as about $-196^{\circ}C$. As the half of robotic arm is in the air and the rest part is submerged in liquid nitrogen, the temperature of robotic arm varies from ambient to liquid nitrogen temperature. In this study the temperature variation of upper part of arm above tank lid was thermally analysed by using the commercial code of Ansys. The result of analysis was that the upper part of robotic arm was seriously frozen due to heat transfer from liquid nitrogen as low as -$120^{\circ}C$. In order to solve the frost problem of robotic arm, small PTFE tube block as resistance material was introduced into the lower part of tank lid instead of the whole stainless steel(SUS) robotic arm. The results showed that the temperature of robotic arm above the lid was higher enough, and this method would be one of the very effective measure to solve the problem.

• Journal of Surface Science and Engineering
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• v.32 no.6
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• pp.709-716
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• 1999

Ceramic is select for an alternative substrate material for high-speed circuits due to its low-thermal expansion. As, in this study, ceramic was prepared by ISG (interlayer sol-gel) process using metal salts and a metal alkoxide as the starting materials. Generally ceramic substrate is used electroless copper plating for the metallization. But it has been indicate weakely the adhesion strength between the substrate and copper layer. Therefore, this research, using the ISG process on the preparation of homogeneous and possible preparation at law temperature fabricated sol solution. Using of the dip coating method was coated for the purpose of giving the anchoring effect on the coating layer and enhancing the adhesion strength between the $Al_2$O$_3$ substrate and copper layer. This study examined primary the characteristic of the sol making condition and differential thermal analysis (DTA) X-ray diffraction (XRD) were mearsured to identify the crystal phase of heat treatment specimens. The morphology of the coated films were studied by scanning electron microscopy(SEM). As a resurt, XRD analysis was obtained patterns of $\alpha$-cordierite after heat-treatment about 2 hours at $1000^{\circ}C$. SEM analysis could have seen a large number of voids on coated film. The more contants of$ Al_2$$O_3$ Wt% was increased the more voids was advanced. Peel adhesion strength has a maximum in the contants of the TEOS:ANE of 1:0.7 mole%. In this case, adhesion strength has been measured 1150gf, peel adhesion strength were about 10 times more than uncoated of the ceramics film.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.158-161
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• 2005

The fiber-reinforced composite materials have been advanced for various applications because of its excellent mechanical and electromagnetic properties. On their manufacturing processes, however, thermo-curing inherently produces the undesired thermal deformation mainly from temperature drop from the process temperature to the room temperature, so called spring-back. The spring-back must be removed to keep the precision of designed shape. In this research, the spring-back of {glass fiber / epoxy}+{carbon fiber / epoxy} unsymmetric hybrid composites were predicted using Classical Lamination Theory (CLT), and compared with the experimental data. Additionally, using finite element analysis (ANSYS), the predicted data and experimental data were compared. The predicted values by CLT and ANSYS were well matched with experimental data.

• Journal of Advanced Research in Ocean Engineering
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• v.4 no.1
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• pp.1-6
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• 2018

Subsea pipelines are designed to transport mixtures of oil, gas, and their associated impurities from the wellhead that can have temperatures as high as $100^{\circ}C$, while the external temperature can be as low as $5^{\circ}C$. Heat can be lost from the subsea pipeline containing high-temperature fluid to the surrounding environment. It is important that the pipeline is designed to ensure that the heat loss is small enough to maintain flow and avoid the unwanted deposition of hydrate and wax, which occurs at a critical temperature of approximately $40^{\circ}C$. Therefore, it is essential to know the heat loss of subsea pipelines under various circumstances. This paper presents a comparison between numerical analyses and existing theoretical formulas for different backfills and burial depth.

• 연구논문집
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• s.29
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• pp.173-183
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• 1999

The vacuum investment casting process for a large gas turbine component, Inner Preswirl Support (IPS), was simulated by using commercial FEM package ProCAST(TM) with view factor radiation method. The solid fraction in mushy zone was directly measured by Differential thermal analysis(DTA-DSC mode). Three types gating design. considering liquid flow and heat release through it. were proposed. Solidification had begun at the ribs or thin sections of the IPS casting and advanced further through the upper and lower gates. The computed temperature gradient G and G/R values at 70% solidified temperature were used for prediction of microshrinkage formation during casting. The effect of mold preheat on the thermal history of the casting displayed minute effect on the microshrinkage formation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.11
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• pp.1767-1776
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• 2001

For the stable operation of high speed air spindle, the low rotational inertia and high damping ratio of spindle shafts as well as high fundamental natural frequency are indispensable. Conventional steel spindles are net appropriate for very high speed operation because of their high rotational inertia and low damping ratio. In this study, a high speed spindle composed of carbon fiber epoxy composite shaft and steel flange was designed for maximum critical speed considering minimum static deflection and radial expansion due to bending load and centrifugal force during high speed relation. The stacking angle and the stacking thickness of the composite shaft and the adhesive bonding length of the 7teel flange were selected through vibrational analysis considering static and thermal loads due to temperature rise.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.1
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• pp.131-136
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• 2008

The double-walled steel vessel with powder insulation in the space between the walls is used to minimize heat transfer by radiation and conduction in cryogenic storage tank. The vacuum required the insulation is much less extreme than with high-vacuum or multilayer insulations. The solid supports are used to bear the weight of the inner container. Thermal and structural analysis of the tank have been carried out to study the effect of vacuum and weldment geometry of the internal supports. Heat flux in wall is increased with increasing of thermal conductivity of perlite. Heat flux and stress of support is not affected by weldment geometry.