Young-Seup Kim

Monitoring of air pollution by polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans of pine needles in Korea.

The atmospheric contamination levels of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were evaluated from the analysis of pine needles in South Korea. Pine needles were collected from 30 sampling points at five main cities in South Korea (Busan, Daegu, Gwangju, Changwon and Jeju island). The highest concentrations of PCDDs/DFs (2.19-26.88 pg I-TEQ/g of dry weight) were measured at Busan. where is the city of the highest population density and traffic volume among five cities. The lowest concentration was detected at Jeju with 0.62 pg I-TEQ/g dry weight. suggesting Jeju could be an environmental background area in Korea. The dominant homologues of PCDDs/DFs in pine needles were the lower chlorine-substituted compounds such as tetra CDDs and CDFs, and the distribution ratios of PCDDs/DFs decreased with increase of the number of chlorine substituents. Homologue profiles of pine needle samples were similar to PCDDs/DFs profiles of the vapor phase in the ambient air, and thus the pine needles absorbed the vapor phase of PCDDs/DFs from air. Results suggested that pine needles could be used as an indicator of the atmospheric contamination for PCDDs/DFs in Korea.

Application of groEL gene for the species-specific detection of Vibrio parahaemolyticus by PCR

Aims:  Vibrio parahaemolyticus is a significant cause of human gastrointestinal disorders and is transmitted through ingestion of raw or undercooked contaminated seafood. We used the groEL gene for the species‐specific detection of V. parahaemolyticus from artificially inoculated shellfish, fish and seawater.

Development of a groEL gene–based species‐specific multiplex polymerase chain reaction assay for simultaneous detection of Vibrio cholerae, Vibrio parahaemolyticus and Vibrio vulnificus

To develop an effective multiplex polymerase chain reaction (PCR) for the simultaneous detection of three important Vibrio species, Vibrio cholerae (Vc), V. parahaemolyticus (Vp) and V. vulnificus (Vv) using the groEL gene, a potential phylogenetic marker.

A improvement for the surface solar insolation retrieval from geostationary sensor

A successful retrieval of SSI highly depends on how to describe the cloud attenuation since most of clouds have larger spatial and temporal variability and complicated physical character. Moreover, the accuracy of SSI estimation for cloudy condition is substantially lower than for clear sky. This study aims to generate a neural network-based cloud factor retrieval system, which can improve accuracy of SSI estimation for cloudy condition. In this study, multilayer feed-forward (MLF) neural network (NN) was employed with Levenberg-Marquardt back-propagation (LM-BP) and early stopping method to avoid the over-fitting. The number of hidden nodes was determined by using trial and error method since too complicated network was apt to be over-fitting, while a too simple network structure will have difficult training the network. The validation of the estimated SSI using NN-based cloud factor was performed with pyranometer measurement data obtained from 22 meteorological stations over Korea peninsula. This SSI estimation for cloudy condition showed a good agreement with ground-based measurements (RMSE = 66.0 W/m2). This accuracy indicates that the use of NN-based cloud factor leads an improvement for SSI estimation in comparison with use of previous system of cloud factor.

Development of a precipitation algorithm optimized for the heavy rainfall using TRMM/TMI data

The general goal of this research is to construct new precipitation algorithm optimized for heavy rainfall in Korea peninsular from satellite passive microwave sensor data, such as TRMM/TMI. At the same time, this study assessed the verification of new algorithm with in-situ meteorological measurements and precipitation radar. Finally, this research aims to assess a construction of the GIS database for regional rainfall. KeywordsTRMM/TMI; precipitation; GIS; PCA; SI; PCT.

Estimation of marine meteorological parameters from the satellite data

The simple estimation methods of air temperature and specific humidity at the sea surface are investigated using buoy and satellite data. Air temperature and specific humidity obtained by the regression equations are validated through the comparison with sea truth data. And also in order to certify this method, sensible and latent heat fluxes are compared with those of other methods. Bias of air temperature with MCSST is 0.28 degC with 1.5 degC rmse and 0.98 correlation coefficient. Specific humidity estimated indirectly using buoys data shows also fairly good result in terms of -1.42 g kg/sup -1/ bias and 1.75 g kg/sup -1/ rmse, correlation coefficient 0.97. The statistical results for sensible and latent heat fluxes calculated using the marine meteorological elements which are derived by the present method are comparable with those of previous studies.