• Korean Journal of Remote Sensing
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• v.36 no.5_4
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• pp.1245-1254
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• 2020

In this study, the limitations of the existing water level detection algorithm using CCTV images were recognized and the water level detection algorithm was improved by applying the Region growing technique. It applied three techniques (Horizontal projection profile, Texture analysis, and Optical flow) to estimate the water area, and the results were analyzed in a comprehensive analysis to select the initial water area. The water level was then continuously detected by the Region growing technique, referring to the initial water area. As a result, it was possible to confirm that the exact level of water was detected without being affected by environmental factors compared to the existing level detection algorithm, which had frequent mis-detection phenomena depending on the surrounding environmental factors. In addition, the water level was detected in the video showing flooded roads in urban areas, not in the video of the river. These results are believed to be able to supplement the difficulty of monitoring at all times with limited manpower by automatically detecting the level of water through numerous CCTV footage installed throughout the country, and to contribute to laying the foundation for preventing disasters caused by torrential rains and typhoons in advance.

• Journal of Korean Neurosurgical Society
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• v.29 no.10
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• pp.1289-1295
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• 2000

Purpose : Recent evidence suggests a possible role for leukocytes in brain injury following ischemia and reperfusion. This study examined the temporal profile of ischemic tissue damage and leukocyte response after transient middle cerebral artery occlusion(MCAO) with reperfusion in the mouse. Methods : Focal cerebral ischemia was made by temporary occluding of the stem of the proximal MCA. Two groups of the mouse were investigated : (1) sham operation(n＝10), and (2)those having the arterial occlusion released after 90 minute(n＝20). By 4 hours(n＝10) and 24 hours(n＝10) after the onset of ischemia-reperfusion, fluorescein videoimages were under-taken in the pial venules of the mouse using a closed cranial window technique. Rhodamine 6G was administered as a $80-100{\mu}l/min$ i.v. loading dose and a $30-40{\mu}l/min$ i.v. maintenance dose in saline to selectively label circulating leukocytes. Neuropathologic evaluation for brain injury was accomplished using the histochemical stain 2,3,5-triphen-yltetrazolium chloride(TTC) and hematoxylin and eosin(H & E) stain. Results : The mean number of adherent leukocytes to cerebral venules in the 90 minutes MCAO and 24 hours reperfusion group were $306{\pm}24$ compared with $72{\pm}8$ in the sham operation group. In the TTC staining method, the cortical infarct affecting 34.8% of hemispheric volume were created in all of animals (n＝10) undergoing 90 minute MCAO with 24 hours reperfusion, but the infarcted area were not found in the other(sham operation and 90 minute MCAO with 4 hours reperfusion)groups. In the H & E stain, the brain tissue following 90 minute MCAO with 4 hours reperfusion revealed only a pyknosis of the nuclei with shrunken cytoplasm, but infiltrated leukocytes were not observed. After 24 hours of reperfusion, a many leukocytes were infiltrated within parenchyma and blood vessles. Conclusions : These findings demonstrate the feasiblity of continous in vivo monitoring of leukocyte adherence in cerebral venules and suggest that reperfusion induced leukocyte adherence to venular endothelium may contribute to tissue injury following focal cerebral ischemia.

• Journal of KIISE:Software and Applications
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• v.34 no.9
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• pp.817-827
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• 2007

In the age of ubiquitous environment, huge number of devices and computing services are provided to users. Personalized service, which is modeled according to the character of each and every individual is of particular need. In order to provide various dynamic services according to user's movement, service unit and operating mode should be able to operate automatically with minimum user intervention. In this paper, we discuss the steps of offering approximate service based on user's request in ubiquitous environment. First, we present our simulator designed for modeling the physical resource and computing object in smart space - the infrastructure in ubiquitous. Second, intelligent agents, which we developed based on a FIPA specification compliant multi-agent framework will be discussed. These intelligent agents are developed for achieving the service goal through cooperation between distributed agents. Third, we propose an automated service discovery and composition method in heterogeneous environment using semantic message communication between agents, according to the movement by the user interacting with the service available in the smart space. Fourth, we provide personalized service through agent monitoring anytime, anywhere from user's profile information stored on handhold device. Therefore, our research provides high quality service more than general automated service operation.

• Journal of Environmental Health Sciences
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• v.31 no.5 s.86
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• pp.379-386
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• 2005

[ $PM_{10},\;PM_{2.5},\;CO_2\;and\;CO$ ] in driver cabins of subway line from 5 to 8 were monitored from 07:00 through 21:00 (or 19:30 or 20:00) on May. Driver cabin of subway line 7 showed the highest $PM_{10},\;PM_{2.5},\;CO_2\;and\;CO$ concentrations. General Linear Model indicated that subway line, subway location (ground and underground track) and running time (morning and afternoon) significantly influenced the concentrations of $PM_{10},\;PM_{2.5},\;CO_2\;and\;CO$ (p=0.000). Daily profile of $PM_{10},\;PM_{2.5},\;CO_2\;and\;CO$, expressed as an 30 minutes average, showed similar variation pattern over day period. These concentrations showed the highest concentrations between 07:00 and 09:00 of rush hour, slightly dropped and again rose slightly after 18:00. In correlation analysis, significant relations among $PM_{10},\;PM_{2.5},\;CO_2\;and\;CO$ were detected (p<0.01). In particular, correlation coefficient between $PM_{10}\;and\;PM_{2.5}$ was highly significant (r=0.884). Regression analysis also concluded that $PM_{10}$ concentration significantly explained 71.4% of variation of $PM_{2.5}$ concentration (p=0.000, $R^2=0.714$). Correlations by CO with $PM_{10}\;and\;PM_{2.5}$ were 0.451 and 0.520, which were higher than those by $CO_2$. Further study is needed to examine the sources of $PM_{2.5}$ and CO in subway and to compare pollutants concentration among subway lines.

• Spatial Information Research
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• v.16 no.3
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• pp.279-290
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• 2008

Landslide, one of the serious natural disasters, has Incurred a large loss of human and material resources. Recently, many forecasting or alarm systems based on various kinds of measuring equipment have been developed to reduce the damage of landslide. However, only a few of these equipments are guaranteed to evaluate the safety of whole side of land slope with their accessibility to the slope. In this study, we performed some experiments to evaluate the applicability of a terrestrial LiDAR as a surveying tool to measure the displacement of a land slope surface far a slope collapsing protection system. In the experiments, we had applied a slope stability method to a land slope and then forced to this slope with a load increasing step by step. In each step, we measured the slope surface with both a total station and a terrestrial LiDAR simultaneously. As the result of Slope Fracturing analysis using all targets, the LiDAR system showed that three was 1cm RMSE on X-axis, irregularity errors on Y-axis and few errors on Z-axis compare with Total Station. As the result of Slope Fracturing analysis using continuous targets, the pattern of Slope Fracturing was different according to the location of continuous targets and we could detect a continuous change which couldn't be found using Total station. The accuracy of the LiDAR data was evaluated to be comparable to that of the total station data. We found that a LiDAR system was appropriate to measuring the behaviour of land slope. The LiDAR data can cover the whole surface of the land slope, whereas the total station data are available on a small number of targets. Moreover, we extracted more detail information about the behavior of land slope such as the volume and profile changes using the LiDAR data.

• Journal of Korean Society on Water Environment
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• v.24 no.6
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• pp.718-724
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• 2008

The ion selective microelectrode (ISME) has been used for measuring the ion profile of DO, $NH_4{^+}-N$, $NO_2{^-}-N$ and $NO_3{^-}-N$ in biofilm. In this study we evaluated the detection limit and validity of ISME and applied ISME for the continuous measurement of $NH_4{^+}-N$ and $NO_3{^-}-N$ concentration in the modified Ludzack-Ettinger (MLE) process. Average detection limits of $NH_4{^+}-N$ and $NO_3{^-}-N$ ISME were $10^{-4.44}M$ and $10^{-4.62}M$, respectively. Since the ISME with $5{\sim}10{\mu}m$ of tip diameter showed a faster response time than that of $1{\sim}5{\mu}m$, the ISME with a tip diameter of $5{\sim}10{\mu}m$ was fabricated and used to make real-time ion detections. Direct monitoring of $NH_4{^+}-N$ and $NO_3{^-}-N$ concentrations in the aerobic (2) tank causes the instability of the electromotive force (EMF) for the initial 5~8 hours and also causes remarkable error values of $NH_4{^+}-N$ and $NO_3{^-}-N$ concentration. This phenomenon is caused by aeration and mixing in the reactor. Thus, the measuring chamber was newly designed for the aerobic (2) tank and then the EMF of the ISME were stabilized in less than 1 hour. Errors of $NH_4{^+}-N$ and $NO_3{^-}-N$ concentration were decreased after stabilization of the EMF. The ISME analysis were well corresponded to the results of auto analyzer and ion chromatography. Consequently, the concentration of $NH_4{^+}-N$ and $NO_3{^-}-N$ could be continuously measured for 178 hours by the ISME.

• Ocean and Polar Research
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• v.29 no.2
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• pp.87-99
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• 2007

This study was conducted to understand the source and behavior of organic matter using the fluorescent technique (excitation-emission matrix) as a part of environmental monitoring program in the Korea manganese nodule mining site in the Northeastern Pacific Ocean. Water samples were collected at $0^{\circ},\;6^{\circ}N$, and $10.5^{\circ}N$ along $131.5^{\circ}W$ in August 2005. The concentration of total organic carbon (TOC) ranged from 58.01 to $171.93\;{\mu}M-C$. The vertical distribution of TOC was characterized as higher in the surface layer and decreased with depth. At $6^{\circ}N$, depth-integrated (from surface to 200 m depth) TOC was $337.1\;gC/m^2$, which was 1.4 times higher value than other stations. The exponential decay curve fit of vertical profile of TOC indicated that 59% of organic carbon produced by primary production in the surface layer could be decomposed by bacteria in the water column. Dissolved organic matter is generally classified into two distinctive groups based on their fluorescence characteristics using three-dimensional excitation/emission (Ex/Em) fluorescence mapping technique. One is known as biomacromolecule (BM; protein-like substance; showing max. at Ex 280/Em 330), mainly originated from biological metabolism. The other is geomacromolecule (GM; humic-like substance; showing max. at Ex 330/Em 430), mainly originated from microbial degradation processes. The concentration of BM and GM was from 0.42 to 7.29 TU (tryptophan unit) and from 0.06 to 1.81 QSU (quinine sulfate unit), respectively. The vertical distribution of BM was similar to that of TOC as high in the surface and decreased with depth. However, the vertical distribution of GM showed the reverse pattern of that of BM. From these results, it appeared that BM occupied a major part of TOC and was rapidly consumed by bacteria in the surface layer. GM was mainly transformed from BM by microbial processes and was a dominant component of TOC in the deep-sea layer.

• Journal of the Korean Geosynthetics Society
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• v.13 no.3
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• pp.1-10
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• 2014

Several types of methods such as resistivity survey, ground penetration radar, etc are used for detection of levee leakage and according to the river design guidelines detection of levee leakage is performed by measuring the hydraulic conductivity of levee soil. But, the former can not verify the leakage point and degree of saturation, the latter is an after treatment method. Movable sensor, which is a high-tech TDR system developed since 2000, can obtain directly the dielectric constant profile covering the whole depth of levee. In this study, laboratory and field model experiments were carried out using movable TDR sensor in order to evaluate the applicability as detection system of levee leakage, As the result, movable TDR system has proven to be 3 times more sensitive to water contents than dry unit weight, and the results conclude that the dielectric constant, water contents and density of the ground proved to have a correlation among them, and the dielectric constant is expected to be a basic data on detection of levee leakage.

• Korean Journal of Remote Sensing
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• v.32 no.5
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• pp.413-421
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• 2016

In this study, correlations between Moderate Resolution Imaging Spectroradiometer (MODIS) derived Aerosol Optical Depth (AOD) values and surface-level $PM_{2.5}$ concentrations at Gosan, Korea have been investigated. For this purpose, data from various instruments, such as satellite, sunphotometer, Optical Particle Counter (OPC), and Micro Pulse Lidar (MPL) on 14-24 October 2009 were used. Direct comparison between sunphotometer measured AOD and surface-level $PM_{2.5}$ concentrations showed a $R^2=0.48$. Since the AERONET L2.0 data has significant number of observations with high AOD values paired to low surface-level $PM_{2.5}$ values, which were believed to be the effect of thin cloud or Asian dust. Correlations between MODIS AOD and $PM_{2.5}$ concentration were increased by screening thin clouds and Asian dust cases by use of aerosol profile data on Micro-Pulse Lidar Network (MPLNet) as $R^2$ > 0.60. Our study clearly demonstrates that satellite derived AOD is a good surrogate for monitoring atmospheric PM concentration.

• Analytical Science and Technology
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• v.12 no.3
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• pp.190-195
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• 1999

The metabolism of testosterone ($17{\beta}$-hydroxy-androst-4-en-3-one) was confirmed in horse after a single intramuscular administration of testosterone cypionate (750 mg). Solvent extracts of urine obtained with enzymatic hydrolysis and methanolysis were analyzed by GC/MS after oxime t-butyldimethylsilyl (oxime-TBDMS) derivatization. The structures of four urinary metabolite after testosterone administration in horse were determined based on EI mass spectra and $5{\alpha}$-androstane-$3{\beta}$, $17{\alpha}$-diol and $5{\alpha}$-androstane-$3{\beta}$-ol-17-one as major was confirmed with authentic standard. Also the concentrations of $5{\alpha}$-androstane-$3{\beta}$, $17{\alpha}$-diol, $5{\alpha}$-androstane-$3{\beta}$, $17{\beta}$-diol, dehydroepiandrosterone (DHEA), $5{\alpha}$-androstane-$3{\beta}$-ol-17-one and testosterone were determined in the urine of normal subjects and the urine after administration. The recovery and detection limit in the most drugs were 86.3~94.7% and 1~3 ppb, respectively. Correlation coefficients for calibration were in the range of 0.984~0.999. Excretion profile of testosterone presents the rapid and large increasement up to maximum values at days 5 after administration and the slow regression. The relative ratios of testosterone, its metabolites over DHEA were determined for indication of testosterone administration in horse doping.