• Journal of Advanced Marine Engineering and Technology
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• 제17권1호
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• pp.55-65
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• 1993

Galvanic protection method is one the cathodic protection methods and is mostly used for corrosion prevention of heat exchangers and ship's hull. In this paper, it was investigated that how cathodic potential distribution was varied with according to the bare and painted steel plates in case of galvanic anode protection. The results obtained above were as follows. 1. Cathodic potential distribution of a painted steel plate was smoothed than that of the bare steel plate all over the cathodic surface area. 2. It was shown that polarization potential of the bare steel plate was somewhat shifted to negative potential, on the contrary that of the painted steel plate was somewhat shifted from negative potential to positive potential as time gone by beginning of galvanic anode method. 3. The applied current density in order to maintain constant protection potential(-770mv SCE) in the painted steel plate was less than that of the bare steel plate because of the high resistance polarization of the painted steel plate. 4. It was suggested that required number and life-time of anode for galvanic anode protection could be decided easily with corrosion prevention coefficient obtained by experimental data.

• 한국작물학회지
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• 제51권1호
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• pp.26-31
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• 2006

This study was conducted to determine the optimum number of inter-rows according to distance of drainage furrow (DF) for running-off excessive-water stress (EWS) in paddy field. The most soil water potential was shown in high ridge (distance of DF by 70 cm) cultivation and the soil water potential showed increasing tendency in over four inter-rows cultivation by DF. The growth of soybean reduced by extended inter-row and its reducing level was high, especially, over four inter-rows (DF distance by 2.8 m) because of EWS. The photosynthetic rate decreased in the more extensive field by distance of DF at V5 and R2 stages, especially, in over four interrows cultivation. Also, root activity decreased at wider DF. The yield was reduced with wider distance of DF more extensively, the highest yield of 270 g per $m^2$ at the every row, but yield showed decreasing tendency at over the $4^{th}$ row (2.8 m) cultivation. Soybean cultivation in paddy field could be founded with DF of every other or $4^{th}$ row.

• Wind and Structures
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• 제10권2호
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• pp.99-119
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• 2007

Estimations of wind flow over terrain are often needed for applications such as pollutant dispersion, transport safety or wind farm location. Whilst field studies offer very detailed information regarding the wind potential over a small region, the cost of instrumenting a natural fetch alone is prohibitive. Wind tunnels offer one alternative although wind tunnel simulations can suffer from scale effects and high costs as well. Computational Fluid Dynamics (CFD) offers a second alternative which is increasingly seen as a viable one by wind engineers. There are two issues associated with CFD however, that of accuracy of the predictions and set-up and simulation times. This paper aims to address the two issues by demonstrating, by way of an investigation of wind potential for the Askervein Hill, that a good level of accuracy can be obtained with CFD (10% for the speed up ratio) and that it is possible to automate the simulations in order to compute a full wind rose efficiently. The paper shows how a combination of script and session files can be written to drive and automate CFD simulations based on commercial software. It proposes a general methodology for the automation of CFD applied to the computation of wind flow over a region of interest.

• 대기
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• 제27권4호
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• pp.455-466
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• 2017

In Korea, property and human damages occur annually due to heavy precipitation during the summer. On August 8, 2015, heavy rainfall occurred in the Seoul metropolitan area due to an outflow boundary, and $77mmhr^{-1}$ rainfall was recorded in Gwangju, Gyeonggi Province. In this study, the simulation of the WRF numerical model is performed to understand the cause and characteristics of heavy rainfall using the Conditional Instability of the Second Kind (CISK), potential vorticity (PV), frontogenesis function, and convective available potential energy (CAPE) analyses, etc. Convective cells initiated over the Shandong Peninsula and located on the downwind side of an upper level trough. Large amounts of water vapor were supplied to the Shandong Peninsula along the southwestern edge of a high pressure system, and from the remnants of typhoon Soudelor. The mesoscale convective system (MCS) developed through CISK process and moved over to the Yellow Sea. The outflow boundary from the MCS progressed east and pushed cold pool eastward. The warm and humid air over the Korean Peninsula further enhanced convective development. As a result, a new MCS developed rapidly over land. Because of the latent heat release due to convection and precipitation, strong potential vorticity was generated in the lower atmosphere. The rapid development of MCS and the heavy rainfall occurred in an area where the CAPE value was greater than $1300Jkg^{-1}$ and the fronto-genesis function value of 1.5 or greater coincided. The analysis result shows that the MCS driven by an outflow boundary can be identified using CISK process.

• 한국게임학회 논문지
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• 제11권2호
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• pp.105-114
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• 2011

MMORPG와 같은 게임에서 근접전투가 벌어지는 샷에서 프라이머리 액터들간의 오클루젼이 종종 발생한다. 본 논문은 미디엄 샷(medium shot) 기법으로 오클루젼을 해결하고 오버-숄더 샷(over-shoulder shot) 기법으로 대결구도를 강화하는 미디엄 오버-숄더(Medium and Oversholder, MOS) 기법을 제안한다. 미디엄 샷 기법은 4개의 기준점을 설정하고. 오버-숄더 샷 기법은 측면의 기준점을 가변적으로 위치시키며 오클루더는 두 개의 스피어로 대체한다. 레이와 스피어가 교차하는지 여부로 잠재적 오클루젼 상태가 판별되면 오클루더의 우측 또는 좌측으로 카메라를 이동시키고, 오클루젼이 해결되면 이동을 멈춘다. 실험결과 MOS 기법은 샷당 평균 $13.7{\mu}s$ 의 연산시간의 성능을 보였으며, 오클루젼은 평균 9.26% 비율로 뷰어의 시선 장애에 영향을 주진 않았다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.38-43
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• 2002

A series of tests were performed to investigate the effects of pH and contamination level on cation exchange capacity and zeta potential in kaolinite loaded with lead. Test results show that cation exchange capacity of kaolinite is found to be in the range from 4 to 20meq/100g and it increased with increasing pH up to the converged number about 20meq/100g over pH 8. And then CEC has a tendency to reduce and converge to zero with increasing the concentration of Pb in the kaolinite surface. Moreover, zeta potential of kaolinite contaminated with lead is found to be in the range from -10 to 5mV, and zero point of charge is measured at about pH 3.5. Zeta potential of kaolinite contaminated with lead decreases with increasing pH values and decreasing Pb concentration of kaolinite.

• The Korean Journal of Ecology
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• 제15권1호
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• pp.47-58
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• 1992

This study is to investigate the change of the seasonal patterns of relative water relations parameters by the pressure-volume curves in pinus koraiensis needles. The osmotic potentials at full water saturated(Ψ0, sat) and at incipient plasmolysis(Ψ0, tlp) increased in growing season, while decreased in non-growing season. The maximum bulk modulus of elasticity(Emax), relative water content(RWCTLP), and relativefree water content(FWCtlp) at incipient plasmolysis in non-growing season were higher than these of growing season. The maximum pressure potential(Ψp, max) varied from 1.16 to 2.18MPa, torgor index(TI) varied from 3.1 to 4.7. The osmole number(Ns/dw) and symplastic water (Vo/DW) were variable seasonally. The maximum water content(Vt/DW) and apoplastic water(AW) were relatively high in early growing stage, and then decreased to needle aging. The pressure potential(Ψp) and water potential(Ψ) in winter needles were rapidly decreased with decreasing of relative water content. The matric potential occupied over 10 percent of water potential with less than-2.0 MPa.

• 대기
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• 제24권2호
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• pp.245-251
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• 2014

Statistical trajectory analysis has been widely used to identify potential source regions for chemically and radiatively important chemical species in the atmosphere. The most widely used method is a statistical source-receptor model developed by Stohl (1996), of which the underlying principle is that elevated concentrations at an observation site are proportionally related to both the average concentrations on a specific grid cell where the observed air mass has been passing over and the residence time staying over that grid cell. Thus, the method can compute a residence-time-weighted mean concentration for each grid cell by superimposing the back trajectory domain on the grid matrix. The concentration on a grid cell could be used as a proxy for potential source strength of corresponding species. This technical note describes the statistical trajectory approach and introduces its application to estimate potential source regions of $CO_2$ enhancements observed at Korean Global Atmosphere Watch Observatory in Anmyeon-do. Back trajectories are calculated using HYSPLIT 4 model based on wind fields provided by NCEP GDAS. The identified $CO_2$ potential source regions responsible for the pollution events observed at Anmyeon-do in 2010 were mainly Beijing area and the Northern China where Haerbin, Shenyang and Changchun mega cities are located. This is consistent with bottom-up emission information. In spite of inherent uncertainties of this method in estimating sharp spatial gradients within the vicinity of the emission hot spots, this study suggests that the statistical trajectory analysis can be a useful tool for identifying anthropogenic potential source regions for major GHGs.

• Journal of Korean Medical Science
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• 제33권50호
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• pp.326.1-326.10
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• 2018

Background: This retrospective study analyzed the causes of failure in the management process from the identification of brain-dead potential organ donors to actual donation in Korea over the past 5 years. Methods: Data of 8,120 potential brain deaths reported to the Korea Organ Donation Agency were used, including information received at the time of reporting, donation suitability evaluation performed by the coordinator after the report, and data obtained from interviews of hospital medical staff and the donor's family. Results: From January 2012 to December 2016, the total number of brain-dead potential organ donors in Korea was 8,120, of which 2,348 (28.9%) underwent organ procurement surgery with designated recipients. While the number of transplant donors has increased over time, the ratio of transplant donors to medically suitable brain-dead donors has decreased. The common causes of donation failure included donation refusal (27.6%), non-brain death (15.5%), and incompatible donation (11.6%); 104 potential donors (7.8%) were unable to donate their organs because they were not pronounced brain dead. Conclusion: The rate of successful organ donation may be increased by analyzing the major causes of failure in the brain-dead organ donation management process and engaging in various efforts to prevent such failures.

• International Journal of Computer Science & Network Security
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• 제22권9호
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• pp.307-315
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• 2022

The review of known decision-making support systems and technologies regarding the possibility of donation and transplantation showed that currently there are no systems and technologies of decision-making support regarding the possibility of donation and transplantation considering civil law. The paper models the decision-making support process regarding the possibility of donation and transplantation, which is a theoretical basis for the development of rules, methods and technology of decision-making support regarding the possibility of donation and transplantation considering civil law. The paper also developed the technology of decision-making support regarding the possibility of donation and transplantation considering civil law as a component of the Unified State Information System for Organ and Tissue Transplantation, which automatically and free of charge determines the possibility/impossibility of donation and transplantation. In the case of the possibility of donation, the admissible type of donation is also determined - over-life or after-life donation - and data about potential donor is entered in the relevant Donor Register. In the case of the possibility of transplantation, if the recipient needs a transplant of one of the paired organs or a part of the organ/tissue, then data about potential recipient are entered in the Transplantation List from both over-life and after-life donor, otherwise, if the recipient needs a transplant of a non-paired organ or both paired organs, then data about potential recipient are entered only in the Transplantation List from after-life donor.