• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.759-762
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• 2008

A wastewater treatment plant located in coastal areas should be built considering the discharge of rainwater and treated water into the sea. The current Hagik Wastewater Treatment Plant in Incheon City was designed in the surface discharge method, which refers to discharging treated water directly into the sea. This method may cause hydrodynamic issues in a wastewater treatment plant because seawater enters an outfall riser when the level of discharged water is lower than the tidal level on a shore with high tidal range. In this study, a method for installing a weir in the discharge manhole was proposed in order to prevent seawater from entering the outfall riser of a wastewater treatment plant. Its feasibility was reviewed by calculating the hydrodynamic that had occurred due to the installation of the weir. As a result, seawater did not enter in the discharge manhole. Thus, even if the coast of Incheon City reaches the highest tidal level, treated water will be able to be properly discharged.

• Analytical Science and Technology
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• v.13 no.4
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• pp.440-445
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• 2000

The techniques for manipulation of various micro-tools were essential for particle isolation and chemical analysis of micro-size particles. This report described the detailed techniques for the preparation and handling of several micro-tools. Presence of uranium particles in smeared filter paper were identified by using the solid track detector. The uranium particles were isolated using the micro-tools under the stereomicroscope and then transferred to the filament of TIMS for the determination of isotope ratios.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.2
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• pp.109-115
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• 2017

Using the computational fluid dynamics (CFD) technique, we performed a numerical simulation in anodesupported solid oxide fuel cell (SOFC). The effect of gas channel/rib width on the cell performance and temperature uniformity was investigated in planar type SOFC. The open source CFD toolbox, OpenFOAM, was used as a numerical analysis tool. As a result, the effect of gas channel/rib width on the cell performance and temperature uniformity was not significant if the oxygen depletion is not occurring. On the other hand, the usage of a wide rib and operation at high current density may lead to performance degradation due to oxygen depletion.

• Geophysics and Geophysical Exploration
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• v.3 no.2
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• pp.39-47
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• 2000

A great deal of computing time and a large computer memory are needed to solve wave equation in a large complex subsurface layers using the finite difference method. The computing time and memory can be reduced by decreasing the number of grid points per minimum wave length. However, the decrease of grids may cause numerical dispersion and poor accuracy. In this study we performed the grid dispersion analysis for several rotated finite difference operators, which was commonly used to reduce grids per wavelength with accuracy in order to determine the solution for the acoustic wave equation in frequency domain. The rotated finite difference operators were to be extended to 81, 121 and 169 difference stars and studied whether the minimum grids could be reduced to 2 or not. To obtain accuracy (numerical errors less than $1\%$) the following was required: more than 13 grids for conventional 5 point difference stars, 9 grids for 9 difference stars, 3 grids for 25 difference stars, and 2.7 grids for 49 difference stars. After grid dispersion analysis for the new rotated finite difference operators, more than 2.5 grids for 81 difference stars, 2.3 grids for 121 difference stars and 2.1 grids for 169 difference stars were needed. However, in the 169 difference stars, there was no solution because of oscillation of the dispersion curves in the group velocity curves. This indicated that the grids couldn't be reduced to 2 in the frequency acoustic wave equation. According to grid dispersion analysis for the determination of grid points, the more rotated finite difference operators, the fewer grid points. However, the more rotated finite difference operators that are used, the more complex the difference equation terms.

• Journal of the Korean Electrochemical Society
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• v.13 no.4
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• pp.256-263
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• 2010

A Crofer 22 APU mesh coated with a conductive ceramic material was developed as an alternative cathode current collector to Ag-based materials for solid oxide fuel cells. $(La_{0.80}Sr_{0.20})_{0.98}MnO_3$ (LSM) layer was deposited onto the Crofer mesh using a spray-coating technique, in an attempt to mitigate the degradation of electrical properties due to surface oxidation at high temperatures. The oxidation experiments at $800^{\circ}C$ in air indicated that the areaspecific resistance (ASR) of the LSM-coated Crofer mesh was strongly dependent on the wire diameter and the contact morphology between mesh and cell. In addition, the post-heat-treatment in $H_2/N_2$ resulted in a reduced thickness of Cr-containing oxide scales at the interface between Crofer mesh and LSM layer, leading to a decreased ASR.

• Journal of the Korean earth science society
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• v.34 no.3
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• pp.195-208
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• 2013

We employed electrical resistivity and optical borehole imaging methods to identify underground cavities and determine ground subsidence rate at the study area affected by land subsidence due to abandoned underground mines. At the study site 1, the anomalous zones of low resistivity ranging between 100 ohm-meter and 150 ohm-meter were observed and confirmed as an abandoned underground mine by subsequent borehole drilling and optical borehole imaging. Although the electrical resistivity survey was unavailable due to the paved surface of the study site 2, we were able to locate another abandoned underground mine with the collapsed mine shaft based on the distribution of the ore veins and confirmed it with borehole drilling. In addition, we measured vertical displacements of underground features indicating underground subsidence by conducting optical borehole imaging 6 times over a period of 43 days at the study site 2. The displacement magnitude at the deep segment caused by subsidence appeared to be 3 times larger than those at the shallow segment. Similarly, the displacement duration at the deep segment was 4 times longer than those at the shallow segment. Therefore, the combination of electrical resistivity and optical borehole imaging methods can be effectively applicable to detect and monitor ground subsidence caused by underground cavities.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.20 no.2
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• pp.82-89
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• 2009

Objectives: Children with attention-deficit hyperactivity disorder(ADHD) often have difficulties in social behavior. The aim of this study was to evaluate the effectiveness of a short-term training program for improving social skills, self-perception and attention deficits. Methods: The subjects were nine children diagnosed with ADHD with(or without) other mental disorders using the Diagnostic Interview Schedule for Children(DISC-ADHD) module. Children were given eight sessions of a social skills training program. Parents of children simultaneously participated in their own training which was designed to support their children's generalization of skills. Assessments included child, parent and teacher ratings of social skills, self-perception and attention deficit at baseline and post-treatment. Results: Social skills training led to significant improvements in child-reported measures of self-esteem, in teacher reported measures of social skills, and in parent-reported measures of attention deficit. Conclusion: This study suggests that short-term social skills training programs for children with ADHD may improve their social skills, self-perception and attention deficits.

• Tuberculosis and Respiratory Diseases
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• v.68 no.4
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• pp.212-217
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• 2010

Background: Acyl protein thioesterase-1 (APT1) is a cytosolic protein that may function in the depalmitoylation of numerous proteins, including the Ras family. However, the clinical role of depalmitoyl thioesterase in human cancer is not known. We evaluated the APT1 expression in lung cancer tissue and its clinicopathological findings according APT1 expression pattern. Methods: APT1 expression was examined by immunohistochemistry in the tumor tissue from 79 patients, who had undergone curative surgical removal of the primary lesion; all patients had been diagnosed with stage I non-small cell lung cancer between 1993 and 2004, at Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea. Results: The APT1 expression was seen in 50 out of 79 (63.3%) cases. The positive APT1 expression was significantly related with histologic subtype and T stage, but was not influenced by differentiation. The positive APT1 expression was not significantly related to patient age, gender, or smoking history. The median follow-up duration was 10.0 years; the 5-year survival rate was 71.0%. The positive APT1 expression group showed significantly worse overall survival and worse disease-free survival without statistical significance. Conclusion: We conclude that positive APT1 expression in stage I lung cancer after surgery is closely associated with overall survival. To evaluate APT1 as a prognostic marker in lung cancer, comprehensive studies on advanced stage cases are needed.

• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.710-714
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• 2011

In present work, $La_{0.8}Ca_{0.2}CrO_{3}$(LCC), $La_{0.8}Sr_{0.2}CrO_{3}$(LSC) and $La_{0.8}Ca_{0.2}CrO_{0.9}Co_{0.1}O_{3}$(LCCC) ceramic interconnect layer for SOFC were prepared by using thermal plasma spray coating process. The LCC, LSC and LCCC powders were characterized by x-ray diffraction(XRD), scanning electron microscopy(SEM), particle counter and BET analysis. In addition, basic and essential properties such as the surface morphology, cross section, gas leak rate, and electrical conductivity of LCC, LSC, and LCCC layers coated by thermal plasma spray coating process were analyzed and discussed. Based on these experimental results, it can be concluded that the LCCC layer coated by thermal plasma spray coating process can be suitable as a ceramic interconnect of SOFC.

• Korean journal of applied entomology
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• v.47 no.2
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• pp.149-154
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• 2008

Pyrausta panopealis is the major pest in green perilla. The larva weaves a web on the shoot of green perilla and damages. In case of extreme, The larva cuts the main branch of green perilla and the leaf of green perilla isn't harvested anymore. A field study was conducted to estimate economic injury levels (EILs) and control thresholds (CTs) for P. panopealis injuring green perilla in green-houses. Different densities of P. panopealis ranged from 1 to 20 crops (2 units per crop) per 100 crops on 13. June, early inoculation. The number of injured leaf and the rate of injured crop were increased by 23. June, on the other hand were decreased after that day. Also, the amount of yield sow the same result above. The economic loss time calculated by the ratio of cost managing this moth to market price (C/V) (C: cost managing a moth, V: Market price) was 4.0%. The economic injury level was 5.1 larval per 100 crops. The control thresholds calculated by 80% level of economic injury level was 4.1 larval per 100 crops.