• Journal of Environmental Impact Assessment
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• v.9 no.3
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• pp.249-255
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• 2000

The comparison of three different kind of simulation by screen3 model, Tem-8 model and EPA formula were undertaken to get a potential concentration and hourly maximum concentration of fugitive dust produced from each construction site in the downtown area of puchon city. The amount of dust estimate U.S EPA formula and fugitive dust formula 22.6078g/sec, 27.9572g/sec respectively. Hourly maximum concenstration at the distance from each construction site by screen3 model are average of $78.89{\sim}728.40{\mu}g/m^3$ and Tem-8 model are $97{\mu}g/m^3$ in site-1, $241{\mu}g/m^3$ in site-2, $268{\mu}g/m^3$ in site-3, $232{\mu}g/m^3$ in site-4, $69{\mu}g/m^3$ in site-5, $36{\mu}g/m^3$ in site-6. Through our experiment, Screen3 model is more encouragingly used than any other model.

• Korean Journal of Clinical Pharmacy
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• v.6 no.2
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• pp.7-13
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• 1996

The purposes of this study were to define the pharmacokinetic parameters of vancomycin in Korean neonates, to evaluate current neonatal vancomycin dosing guideline being used in a teaching hospital, and to develop the optimal vancomycin dosing guideline. The evaluation of 35 sets of peak and trough concentrations drawn on current dosing regimen showed that $29\%$ of peak concentrations and $46\%$ of though concentrations were within therapeutic range. Otherwise, pharmacokinetic parameters, based on 62 sets of peak and trough serum concentrations obtained from 39 neonates, showed that mean vancomycin clearance (CL), volume of distribution (Vd), and terminal elimination half-life were $0.13\pm0.08\;L/hr,\;0.94\pm0.48\;L,\;and\;5.6\pm2.13$ hours, respectively. Volume of distribution (Vd) normalized for body weight remained constant throughout PCA range, whereas the absolute CL (r=0.74) and normalized CL (r=0.36) showed high correlation with PCA. Also, the normalized CL showed a strong inverse correlation (r=-0.55) with serum creatinine concentrations (SrCr). Based on the high correlation among PCA serum creatinine concentration, CL, and the daily dosage requirements, the following dosing guideline for vancomycin in neonates was suggested: 10 mg/kg $12{\sim}18$ hourly for < 30 weeks PCA and < 0.6 mg/dl SrCr; 10 mg/kg 18 hourly for < 30 weeks PCA and $0.6{\sim}1.2$ mg/dl SrCr; 10 mg/kg 8 hourly for $30\sim44$ weeks PCA and < 0.6 mg/dl SrCr; 10 mg/kg 12 hourly for $30\sim44$ weeks PCA and $0.6{\sim}1.2$ mg/dl SrCr.

• Ocean and Polar Research
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• v.31 no.1
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• pp.63-70
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• 2009

Eutrophicated water fed through Mankyeong River and Dongjin River into the new Saemankeum Lakemight seriously affect the water quality and phytoplankton community in the lake. To obtain control reference data for the later studies on environmental changes due to the construction of the Saemankeum Sea Wall, we performed a monthly investigation on the physico-chemical properties of the water and phytoplankton community at 3 stations in the Mankyeong River Estuary over 14 months starting from September 1999. Water temperature ranged from $0.3{\sim}32.9^{\circ}C$ due to the typical seasonal variations in temperate on the coasts and salinity exhibited a wide annual range of $0.2{\sim}33.7$ psu along with regular and huge hourly variations according to tidal cycles. Inorganic nutrients were supplied from rivers to the monitoring station and the whole lake. The average concentration of total-N, $6.99\;mg{\cdot}l^{-1}$, was higher than the water quality for agricultural use with peak values occurring in winter. Species composition showed a seasonal succession pattern, where a high diversity was observedin summer and autumn and vice versa in winter. Hourly variations of water properties in the "Mankyeong bridge" Station were quite regular and well in accordance with the daily tidal cycles. The different degree of sea water intrusion during the flood tide at each of the 3 stations exhibited a different range and variation pattern of water temperature and salinity throughout a day. Hourly changes in species composition were in harmony with the daily tidal cycles, resulting in extremely variable spatio-temporal variation.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.1029-1037
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• 2020

The machine learning algorithm has been widely used in water-related fields such as water resources, water management, hydrology, atmospheric science, water quality, water level prediction, weather forecasting, water discharge prediction, water quality forecasting, etc. However, water quality prediction studies based on the machine learning algorithm are limited compared to other water-related applications because of the limited water quality data. Most of the previous water quality prediction studies have predicted monthly water quality, which is useful information but not enough from a practical aspect. In this study, we predicted the dissolved oxygen (DO) using recurrent neural network with long short-term memory model recurrent neural network long-short term memory (RNN-LSTM) algorithms with hourly- and daily-datasets. Bugok Bridge in Oncheoncheon, located in Busan, where the data was collected in real time, was selected as the target for the DO prediction. The 10-month (temperature, wind speed, and relative humidity) data were used as time prediction inputs, and the 5-year (temperature, wind speed, relative humidity, and rainfall) data were used as the daily forecast inputs. Missing data were filled by linear interpolation. The prediction model was coded based on TensorFlow, an open-source library developed by Google. The performance of the RNN-LSTM algorithm for the hourly- or daily-based water quality prediction was tested and analyzed. Research results showed that the hourly data for the water quality is useful for machine learning, and the RNN-LSTM algorithm has potential to be used for hourly- or daily-based water quality forecasting.

• Journal of Korean Society for Atmospheric Environment
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• v.5 no.1
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• pp.88-95
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• 1989

The aspects of the occurence frequency of $SO_2$ concentration were studied with the observed data in Seoul and the scheme that is capable of estimating not only highest concentration for a variety of averaging times but also concentrations for arbitary occurrence frequency with long term arithmatic mean and geometric standard deviation data, was evaluated. The results of the statistical analysis show that the occurrence frequency is almost log normal except a few cases, and 3rd highest values of daily mean concentration were about 4.2 $\sim$ 5.2 times higher than annual arithmatic mean. The evaluation with the observed hourly concentration shows that the scheme fairly well estimate the short concentration of arbitary occurrence frequence and it can be used for air quality management and environmental impact assessment.

• Journal of Environmental Science International
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• v.21 no.8
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• pp.953-963
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• 2012

The annual variations of the urban heat island in Busan is investigated using surface temperature data measured at 3 automatic weather stations(AWSs) for the 5 years period, 2006 to 2010. Similar to previous studies, the intensity of the urban heat island is calculated using the temperature difference between downtown(Busanjin, Dongnae) and suburb(Gijang). The maximum hourly mean urban heat island are $1.4^{\circ}C$ at Busanjin site, 2300LST and $1.6^{\circ}C$ at Dongnae site, 2100LST. It occurs more often at Dongnae than Busanjin. Also the maximum hourly mean urban heat island appears in November at both sites. The urban heat island in Busan is stronger in the nighttime than in the daytime and decreases with increasing wind speed, but it is least developed in summer. Also it partly causes the increasement of nighttime PM10 concentration.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.1
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• pp.65-72
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• 1995

This paper describes the applications of the SCS TR-20 hydrologic model for simula- tion of hourly inflow rates from sixty-six ungaged tributaries and subareas between the Naju station and the estuarin dam at the Yongsan River Basin. The model was tested for the ungaged conditions with fifteen storm events at Naju station. Hourly simulated run- off data were compared with the observed, and the results showed less correlationships between the two data than those from TANK model. The coefficients of correlation ranged from 0.74 to 0.87. The curve numbers and time of concentration were defined from topographic dta for each of sixty-six tributaries for the estuarine dam and used for TR-20 applications. The results were within an acceptable range of errors in simulating the inflow fluctuations for the flood forecasting at the estuarine dam.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.5
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• pp.57-65
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• 2007

The objective of this study was to evaluate chemical water quality by hourly monitoring(25hr) of Saemangeum esturary. For this study, we selected 2 sites like a Mangyong Bridge(St. 6) and Dongjin Bridge(St. 7). Inflow of salt water was not detected during low tide(maximum 553, 508cm) of all stations, while the salinity rises were detected in spring tide(750cm). When 602m of maximum tide was reached, salinity concentration was increased at St. 7, while there was no change in St. 6. Therefore, We know that salinity variation is greatly influenced by tide height at survey site. Also, significant variance of salinity(p<0.05) was found between St. 6 and St. 7 because dike construction made the flood tide move into the Dongjin river. Total suspened solids(TSS) concentration was increased because of the river runoff at St. 6, and also the turbulance and resuspension according to salt intrusion at St. 7. During the high tide, the water discharge from the sea seemed to dilute the nutrient but to elevate TSS concentration in St. 7. Silicate and nitrate concentrations in the studied site were decreased by the mixing of sea water, whereas the evident trend of phosphate concentration was not found. This result can be explained by the phosphorus condition. Phosphorus exists inactive when it is affected by hydrated iron and adsorbed onto suspended matters. Compared to the environmental conditions of the St. 6 and St. 7, physical factors such as temperature, dissolved oxygen and TSS have statistically no significant difference(p<0.001), but nutrient concentrations were higher at St. 6 than St. 7. It could be suggested from these results that it is important to control the discharge of fresh water by sewage treatment plants located in St. 6 for water quality management.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.6
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• pp.780-788
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• 2013

This study attempted to determine important meteorological parameters related to airborne pollen concentrations in urban areas. Hourly pollen measurement data were prepared from a regular sampling with a volumetric Burkard spore trap at a site in the Ulsan city, during the spring season (March~May) of 2011. Results showed that the daily mean and maximum concentrations for total pollen counts during the spring season were statistically significantly correlated with both air temperature and wind speed; daily mean pollen concentration was the most highly related to daily maximum temperature (r=0.567, p<0.001). It was also identified that pollen concentration has a stronger relationship with wind speed at the rural site than at the urban one, which confirms that strong wind conditions over the pollen sources area can be favorable for pollen dispersal, resulting in increases in airborne pollen concentrations downwind. From the results of an oak-pollen episode analysis, it was found that there was a significant relationship between hourly variation of oak pollen concentrations and dynamic meteorological factors, such as wind and mixing height (representing the boundary layer depth); especially, a strong southwestern wind and elevated mixing height was associated with high nocturnal concentrations of oak pollen. This study suggests that temperature, wind, and mixing height can be important considerations in explaining the pollen concentration variations. Additional examination of complex interactions of multiple meteorological parameters affecting pollen behavior should be carried out in order to better understand and predict the temporal and spatial pollen distribution in urban areas.

• Particle and aerosol research
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• v.16 no.1
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• pp.19-30
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• 2020

The organic carbon in the ambient particulate matter (PM) is divided into primary organic carbon (POC) and secondary organic carbon (SOC) by their formation way. To regulate PM effectively, the estimation of the amount of POC and SOC separately is one of important consideration. Since SOC cannot be measured directly, previous studies have evaluated determination of SOC by the EC tracer method. The EC tracer method is a method of estimating the SOC value from calculating the POC by determining (OC/EC)pri which is the ratio of the measured values of OC and EC from the primary combustion source. In this study, three different ways were applied to OC and EC concentrations in PM_2.5 measured at Seoul for determining (OC/EC)pri: 1) the minimum value of OC/EC ratio during the measurement period; 2) regression analysis of OC vs. EC to select the lower 5-20% OC/EC ratio; 3) determining the OC/EC ratio which has lowest correlation coefficient value (R²) between EC and SOC which is reported as minimum R squared method (MRS). Each (OC/EC)pri ratio of three ways are 0.35, 1.22, and 1.77, respectively from the 1 hourly data. We compared the (OC/EC)pri ratio from 1hourly data with 24 hourly data and revealed that (OC/EC)pri estimated from 24 hourly data had twice larger than 1hourly data due to the low time resolution of sampling. We finally confirmed that the most appropriate value of (OC/EC)pri is that calculated by a regression analysis of 1 hourly data and estimated SOC amounts at PM_2.5 of the Seoul atmosphere.