• Proceedings of the KSRS Conference
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• v.2
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• pp.752-755
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• 2006

Evaportranspiration is an important factor in hydrology cycle. Traditionally, it is measured by using basin or empirical formula with meteorology data, while it does not represent the evaportranspiration over a regional area. With the advent of improved remote sensing technology, it becomes a surface parameter of research interest in the field of remote sensing. Airborne and satellite imagery are utilized in this study. The high resolution airborne images include visible, near infrared, and thermal infrared bands and the satellite images are acquired by MODIS. Surface heat fluxes such as latent heat flux and sensible heat flux are estimate by using airborne and satellite images with surface meteorological measurements. We develop a new method to estimate the evaportranspiration over the rice paddy. The surface heat fluxes are initialized with a surface energy balance concept and iterated for convergent solution with atmospheric correct functions associated with aerodynamic resistance of heat transport. Furthermore, we redistribute the total net energy into sensible heat and latent heat fluxes. The result reveals that radiation and evaporation controlled extremes can be properly decided with both airborne and satellite images. The correlation coefficient of latent heat flux and sensible heat flux with corresponding in situ observations are 0.66 and 0.76, respectively. The relative root mean squared errors (RMSEs) for latent heat flux and sensible heat flux are 97.81 $(W/m^2)$ and 124.33 $(W/m^2)$, respectively. It is also shown that the newly developed retrieval scheme performs well when it is tested by using MODIS date.

• Journal of the Korea Society for Simulation
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• v.27 no.2
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• pp.25-33
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• 2018

When developing military equipment, it should be designed considering the temperature condition so that the operator can operate in a stable environment. The shelter for storing various military equipments is operated in various environments. The storage temperature and operating requirements of the test equipment and repair accessories shall be $-32^{\circ}C$ to $50^{\circ}C$ and the inside of the shelter shall be designed to meet the storage temperature and operating requirements. In this study, thermal analysis of a 2.5 ton military shelter operating under high temperature and solar heat conditions is performed considering MIL-STD-810G. The thermal analysis was applied by using the concept of heat resistance and heat circuit, and the solar thermal test was performed on the actually manufactured military shelter in order to verify the analysis results.

• Nuclear Engineering and Technology
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• v.52 no.2
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• pp.337-343
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• 2020

Oxide dispersed strengthened (ODS) steel is an important candidate for Gen-IV reactors. Oxide embedded in Fe can help to trap irradiation defects and enhances the strength of steel. It was observed in this study that the size of oxide has a profound impact on the depinning mechanism. For smaller sizes, the oxide acts as a void; thus, letting the dislocation bypass without any shear. On the other hand, oxides larger than 2 nm generate new dislocation segments around themselves. The depinning is similar to that of Orowan mechanism and the strengthening effect is likely to be greater for larger oxides. It was found that higher shear deformation rates produce more fine-tuned stress-strain curve. Both molecular dynamics (MD) simulations and BKS (Bacon-Knocks-Scattergood) model display similar characteristics whereby establishing an inverse relation between the depinning stress and the obstacle distance. It was found that (110)_oxide || (111)_Fe (oriented oxide) also had similar characteristics as that of (100)_oxide || (111)_Fe but resulted in an increased depinning stress thereby providing greater resistance to dislocation bypass. Our simulation results concluded that critical depinning stress depends significantly on the size and orientation of the oxide.

• Progress in Superconductivity and Cryogenics
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• v.18 no.1
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• pp.59-63
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• 2016

The superconducting NMR magnets have used cryogen such as liquid helium for their cooling. The conduction cooling method using cryocoolers, however, makes the cryogenic cooling system for NMR magnets more compact and user-friendly than the cryogen cooling method. This paper describes the thermal and structural analysis of a cryogenic conduction cooling system for a 400 MHz HTS NMR magnet, focusing on the magnet assembly. The highly thermo-conductive cooling plates between HTS double pancake coils are used to transfer the heat generated in coils, namely Joule heating at lap splice joints, to thermal link blocks and finally the cryocooler. The conduction cooling structure of the HTS magnet assembly preliminarily designed is verified by thermal and structural analysis. The orthotropic thermal properties of the HTS coil, thermal contact resistance and radiation heat load are considered in the thermal analysis. The thermal analysis confirms the uniform temperature distribution for the present thermal design of the NMR magnet within 0.2 K. The mechanical stress and the displacement by the electromagnetic force and the thermal contraction are checked to verify structural stability. The structural analysis indicates that the mechanical stress on each component of the magnet is less than its material yield strength and the displacement is acceptable in comparison with the magnet dimension.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.2157-2162
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• 2012

Objective: The PI3K/PTEN/AKT/mTOR signaling pathway has been implicated in resistance to cisplatin. In the current study, we determined whether common genetic variations in this pathway are associated with platinum-based chemotherapy response and clinical outcome in advanced non-small cell lung cancer (NSCLC) patients. Methods: Seven common single nucleotide polymorphisms (SNPs) in core genes of this pathway were genotyped in 199 patients and analyzed for associations with chemotherapy response, progression-free survival (PFS) and overall survival (OS). Results: Logistic regression analysis revealed an association between AKT1 rs2494752 and response to treatment. Patients carrying heterozygous AG had an increased risk of disease progression after two cycles of platinum-based chemotherapy compared to those with AA genotype (Adjusted odds ratio (OR)=2.18, 95% confidence interval (CI): 1.00-4.77, which remained significant in the stratified analyses). However, log-rank test and cox regression detected no association between these polymorphisms in the PI3K pathway genes and survival in advanced NSCLC patients. Conclusions: Our findings suggest that genetic variants in the PI3K/PTEN/AKT/mTOR pathway may predict platinum-based chemotherapy response in advanced NSCLC patients in a Chinese population.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.2
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• pp.140-146
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• 2001

In order to analyze the photodegradation of plastic materials for floats or frames of fisheries facilities, weathering experiment on 3 kinds of plastic materials like high density PE of Korea(KHDPE) and Norway(NHDPE) and high strength PVC(Hi-PVC) was carried out during 900 hours exposure by using xenon light source of weather-Ometer. The results obtained are as follows; With increasing of ultraviolet radiation(UVR) time, a remarkable losses in the mechanical properties of each specimen were observed except for the remaining strain of HDPE materials. As NHDPE lost almost 15% of its initial tensile stress during a 900 hours exposure followed by KHDPE 12% and Hi-PVC 6%. In addition, the remaining tensile stress RS(kg/$mm^2$) decreases almost linearly with the lapse of exposure time to light Y(Year) and the empirical equations of each specimen computed as follows; KHDPE : RS=2.6769-0.0003Y($r^2$=0.63) Hi-PVC : RS=5.3470-0.0003Y($r^2$=0.91) NHDPE : RS=2.4929-0.0004Y($r^2$=0.97) It was observed by scanning electron microscope that all specimens with UVR time had started to decompose and had bubbled areas and small holes.

• Korean Journal of Materials Research
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• v.5 no.8
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• pp.929-935
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• 1995

In order to develop COG (Chip On Glass) technology for LCD module interconnecting the driver IC to Al pad electrode on the glass substrate, Anisotropic Conductive Adhesive(ACA) process, the most promising one among COG technologies, was investigated. ACA process was carried out by two steps, dispensing of ACA resin in the bonding area and curing by W radiation. Load on the chip was ranged from 2.0 to 15kg and the chip was heated at about 12$0^{\circ}C$. In resin, the density of conductive particles coated with Au or Ni at the surface were 500, 1000, 2000 and 4000 particles/$\textrm{mm}^2$, and the diameter of particles were 5, 7 and 12${\mu}{\textrm}{m}$. As a result of the experiments, ACA process using ACA particle of diameter and density of 5${\mu}{\textrm}{m}$ and 4000 particles/$\textrm{mm}^2$ respectively shows optimum characteristic with the stabilzed bonding properties and contact resistance.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.524-531
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• 2003

The usefulness of vitrification technology for low- and intermediate- level radioactive wastes was demonstrated because of high volume reduction, mechanical and chemical stability of final waste forms. Thus, a construction of the commercial vitrification plant Is currently promoted. Due to the high radiation level of the waste, shielding analysis has to be carried out for safe design in a vitrification facility. Because there has been no experience in the construction and operation of the vitrification facility in Korea, in this study, in order to get some information for help the detailed design and plan for operation in vitrification facility, shielding analysis for each facility in pilot plant is carried out by using source term from established study. For the selection of the shielding material, concrete was chosen compared to the lead because of economic advantage, weight consideration, and thermal resistance.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.12
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• pp.1337-1344
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• 2007

It is shown that inverted ${\pi}$ feeder affects the gain improvement for the internal antenna of mobile phone. Generation of current on the inverted ${\pi}$ feeder, by the modification of conventional feeding structure for the PIFA and IFA, can apply T matching theory to the new feeder. Therefore, inverted ${\pi}$ feeder based on the T matching theory makes higher radiation resistance, and also increases the gain. To verify inverted ${\pi}$ feeding effect, feeder is applied to GSM/DCS dual band conventional PIFA, and measured return loss and patterns. By measurement, it's shown that this new feeding antenna has $0.23{\sim}0.84$ dB higher average gain for GSM band and $0.01{\sim}1.74$ dB higher average gain for DCS band than conventional fed PIFA without resonant frequency change.

• Korean journal of applied entomology
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• v.22 no.1 s.54
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• pp.41-44
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• 1983

In order to evaluate the technique of P-32 labelling method for screening lines of rice to whitebacked planthopper, the relationship between the amount of ingestion and feeding preference of insects were observed with the resistant and susceptible lines where characteristics were predetermined by comparing their feeding preference and antibiosis method. The feeding preference of the insects was significantly correlated with the amount of P-32 ingestion. It was more manifest in adults than nymphs of the whitebacked planthopper. The density of nymph and radioactivity of P-32 were high in the susceptible line. This suggested that deforming the ingestion amount of P-32 in the insects seemed to be useful technique for accurate screening. For this technique, the uniform labelling of P-32 on the rice seedings was prerequisite and the uniformity was increased by triming roots and leaves in the length and number.