• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.7
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• pp.819-825
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• 2014

The diurnal range of temperature in korea is increasing. We know that the environment has deteriorated through report about railway damage and economic loss caused by climate. In these conditions, Monitoring device for railway must operate to support the operations and maintenance. Therefore, In this paper, COM-based monitoring device implemented using Industrial-Extended electronic components and made, We tested compliance about temperature environment of actual railway. We verified through testing about cold and dry heat of monitoring device. Used components in this product will be able to utilize the development of the railway industry of electronics.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.2
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• pp.157-167
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• 2001

Although PAN has ong been considered to belong to one of the most characteristic photooxidants, its concentra-tions have rarely been measured in a systematic manner in Korea. The first in-situ Measurements of PAN were made in concert with simultaneous analysis of NO, NO$_2$, $O_3$ and UV-Visible radiation intensity from Seoul and dong-Hae during Spring and early Summer of 1999. The aim of our study was to evaluate the behavior of photo-chemical species in a highly polluted urban air and a relative clean one. PAN were determined using a semi-auto-mated gas chromatograph equipped with an electron captured detection system. Calibration of the PAN was done by synthesizing liquid standards using a strong acid nitration of the corresponding peracid. The PAN concentra-tions were found in the range of a few ppbv in the urban air ad persistently less than a ppbv in the clean rural airs. Diurnal variations of PAN and $O_3$ were also observed consistently during the experiment with maxima occurring during the late daylight hours. While the positive dependency of $O_3$ production and PAN concentrations were ob-served in most occasion, the dependency became deviated significantly under changes in air masses.

• Asian Journal of Atmospheric Environment
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• v.4 no.3
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• pp.166-176
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• 2010

In this research, the environmental behavior of carbon dioxide ($CO_2$) was investigated in a mountainous site in the proximity of a highly industrialized megacity, Seoul, Korea. The concentration data of $CO_2$ monitored routinely at hourly intervals at Mt. Gwan-Ak (GA), Seoul, Korea throughout 2009 were analyzed in several respects. The mean $CO_2$ value was $405{\pm}12.1$ ppm (median=403 ppm) with a range of 344 to 508 ppm (N=8548). The analysis of its seasonal trend indicated that the $CO_2$ levels peaked in the winter but reached a minimum in fall. If the short-term trend is analyzed, the $CO_2$ values generally peaked during daytime along with the presence of two shoulders; this is suspected to be indicative of strong man-made effects (e.g., traffic activities). It is seen that the general patterns of $CO_2$ distribution in this study area are highly comparable to those typically found in urban areas with strong signals of anthropogenic activities.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.5
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• pp.359-370
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• 1992

To investigate the flow pattern and mixing process in Suyoung Bay, field observations and data analyses of tidal current, salinity and suspended sediment (SS) were carried out. Ebb flow is stronger than flood flow, and duration of ebb tide is longer than that of flood tide. Semi-diurnal component of tidal current is predominant, and current rotating clockwise occurs in the central part of the bay. The direction of the residual currents in the central part of the bay and offshore is almost N to WNW, and the speed is 4-14cm/s. Eulerian diffusion coefficients estimated from the current data have the range of $6.2\times10^4-4.2\times10^6\;cm^2/s,$ Salinity structure in Suyoung River estuary during flood tide is of partially mixed type, but is of stratified type during ebb tide. Salinity fluctuation is large at the surface, and the fluctuation decreases with depth. SS concentration in Suyoung River estuary has a higher value during ebb tide than that during flood tide. Salinity and 55 concentrations in the estuary appeared to be very sensitive to the change of river flow.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.3-6
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• 2001

Various Parameters such as stream velocities, discharges, and dispersion coefficients of dissolved solutes were estimated by fitting 1-D nonreactive solute transport model to the time-series chemistry data. This study was done for the reaches of Mankyung River lower than the Jeonju Wastewater Treatment Plant (Jeonju WTP). Korea. Concentrations of inorganic chemicals in the stream waters are strongly influenced by mixing with the chemically distinct effluent from Jeonju WTP. Sulfate, EC. and the total major cation were proved to be nearly conservative in the study area front their relationships with chloride, the conservative chemical species. The solute transport model was constrained to the time-series concentrations for these 4 conservative species. The variations of concentration and discharge of Jeonju WTP were used as input parameters, and the stream velocities, dispersion coefficients, and concentrations and discharges of some inflows were optimized. The differences between the observed arid simulated values for alkalinities and nitrates are inversely correlated and show diurnal fluctuations, indicating the photosynthesis. The parameters obtained front this mode] range from 550 to 774 kcmd (stream discharge at the outlet of the study area), from 0.06 to 0.10 m/sec (flow velocity), and from 0.7 to 6.4 m$^2$/sec (dispersion coefficient). The history of Jeonju WTP discharge was well predicted when optimized, indicating the validity of the model results.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.290-293
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• 2007

The land surface temperature (LST) derived from the meteorological satellite can be used to investigate the urban heat island (UHI) and its temporal variations. In this study, we developed LST retrieval algorithm from MTSAT-1R by means of a statistical regression analysis from radiative transfer simulations using MODTRAN 4 for a wide range of atmospheric, satellite viewing angle (SVA) and lapse rate conditions. 535 sets of thermodynamic initial guess retrieval (TIGR) were used for the radiative transfer simulations. Sensitivity and intercomparison results showed that the algorithm, developed in this study, estimated the LST with a similar bias and root mean square errors to that of other algorithms. The magnitude, spatial extent, and seasonal and diurnal variations of the UBI of Korean peninsula were well demonstrated by the LST derived from MTSAT-1R data. In general, the temporal variations of UHI clearly depend on the weather conditions and geographic environment of urban.

• Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.276-282
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• 1998

As a part of the long-term ADCP mooring program to measure the mass flux through the Korea Strait, current velocity data were obtained for 39 days in the deepest point of the strait. Near-surface velocity of this observation was compared with Izuhara-Pusan sea level difference (SLD) to investigate the geostrophic relationship. Principal direction of the Tsushima Current at the mooring station is 44.6 degrees to the north from the east. Variability of the tidal current is greater than the nontidal current by a factor of two. Correlation coefficient of tidal current against SLD is 0.46 but the nontidal current is not correlated. The current velocity (U in cm/s) can be estimated from the demeaned SLD (in cm) by the relation U=23.63+0.64SLD where the maximum range of SLD is 52.9 cm. Current is coherent with SLD at semidiurnal, diurnal and 42.7-hour periods. A dominant nontidal variability with about 5-day period is not coherent with SLD.

• 보존과학연구
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• s.24
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• pp.169-184
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• 2003

Yearly mean temperature and relative-humidity of the Seokguram Grotto was measured $19~23^{\circ}C$, 40~44% from May, 1998 to December,2002. The measurement has little differences comparing to the optimum guideline (temperature : $20^{\circ}\pm2^{\circ}C$, relative-humidity : $50^{\circ}\pm5%$). It is necessary to increase humidity in the Seokguram Grotto during winter because of heating and decrease the temperature during summer because of a higher temperature of outside. In addition, the diurnal range keep in $4^{\circ}C$ of temperature and in 10% of relative-humidity. Yearly mean concentration of $CO_2$(carbon dioxide) was measured538~658ppm that is higher than concentration of normal atmosphere(360 ppm). The $CO_2$ has an cumulative effect on the surface of stone cultural properties as a form of carbonic acid($H_2CO_3$) after reaction with water. HVAC (Heating, Ventilation and Air Conditioning) system should be operated to maintain ideal state for the preservation according to the optimum guideline. Also, the entrance into the Seokguram Grotto should be controlled to prevent a sudden fluctuation of humidity and temperature. Human could carry small particles like a microdust, microbe, etc., into the Seokguram Grotto and also could damage the surface by a direct touch.

• Animal cells and systems
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• v.1 no.4
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• pp.571-576
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• 1997

The playas of the Southern High Plains (SHP) of Texas, USA are an important habitat for over one million wintering waterfowl. However, the recent trend toward the modification of playas for agricultural use is threatening winter habitat of waterfowl in this region. Diurnal activity budgets of wintering mallards (Anas platyrhynchos) were conducted from 1 October to 31 March, 1983-1984, and 1984-1985) at three habitat types; steep-sided pits, terraced pits, and open lakes. All seven activity patterns (feeding, locomotion, resting, comfort, courtship, alert, and agonistic) were different (P<0.05) among the three habitat types for wintering mallards on the SHP of Texas. Terraced pits supported more feeding activity (27.8%) (P<0.001) than steep-sided pits (11.2%) or open lakes (2.6%) due to their abundance of natural seeds and aquatic invertebrates. Hens (17.5%) fed more than drakes (11.7%) (P<0.05). Locomotion (32.2%) and alert (2.8%) behavior across the three habitat types showed the highest level during the early morning (6:00-9:00 AM). Paired mallards rested more (37.9%) than unpaired mallards (25.8%) (P<0.05). Agonistic activity was highest (2.4%) in terraced pits throughout the season.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.E
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• pp.373-381
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• 1993

To understand the human exposure levels of volatile halogenated hydrocar-bons in ambient air, a new rapid and convenient analytical method for determination of the compounds in gaseous phase was evaluated and established. The method is based upon passsive diffusion to personal sampler containing adsorbent and solvent extraction followed by purge trap/ on-column cryof-ocusing method. A new method needs no special instrumentation for gas collection because it is based upon the passive diffusion principle. The typical chromatogram obtained in this study proved that rapid and simultaneous determination of target analytes was possible with good resolution. The developed method was successfully applied to determine the volatile halogenated hydrocarbons in indoor air and the values obtained by this new method were compared with those by direct suction method. The concentration of carbon tetrachloride, 1,1,2-trichloroethylene, chloroform showed the values below 400$\mug/m^3$ except the maximum of 1,513$\mug/m^3$ of chloroform. 1,1,1-Trichloroethane showed approximately 1,000 to 5,000$\mug/m^3$ range of diurnal fluctuation in indoor air.