• Membrane and Water Treatment
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• v.13 no.5
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• pp.245-257
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• 2022

Water quality characteristics and their spatial variations in the Nakdong River were statistically analyzed by multivariate techniques including correlation analysis, CA, and FA/PCA based on water quality parameters for 17 sites over 2017-2019, yielding PI values for primary factors. Site 10 indicated the highest parameter concentrations, and results of pearson's correlation analysis suggest that non-biodegradable organic matter had been distributed on the site. Five clusters were identified in order of descending pollution levels: I (Ib > Ia) > II (IIa > IIb) > III. Spatial variations started from sub-cluster Ib in which Daegu city and Geumho-river are joined. T-P, PO4-P, SS, COD, and TOC corresponded to VF 1 and 2, which were found to be principal components with strong influence on water quality. Sub-cluster Ib was strongly influenced by NO3-N and T-N compared to other clusters. According to the PIs, water quality pollution deteriorated due to non-biodegradable organic matter, nitrogen- and phosphorus-based nutrient salts in the middle and lower reaches, illustrating worsening water pollution due to inflows of anthropogenic sources on the Geumho-river, i.e., sewage and wastewater, discharged from Site 10, at which there is a concentration of urban, agricultural, and industrial areas.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.04a
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• pp.142-143
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• 2006

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.10a
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• pp.371-372
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• 2008

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2010.04a
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• pp.329-330
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• 2010

• Journal of Korean Society of Forest Science
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• v.109 no.1
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• pp.50-61
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• 2020

Street trees are very important to urban environments as they can alleviate air pollution. However, when ozone is absorbed through the stomata, it can induce the formation of free radicals inside the tree, negatively affecting the vegetation. The present study investigated the Air Pollution Tolerance Index (APTI) of four major street tree species: Prunus yedoensis, Zelkova serrata, Chionanthus retusus, and Pinus densiflora. Two-year-old seedlings were placed in a phytotron and fumigated with 100 nL·L^-1 (ppb) ozone for 4 weeks, following which the ascorbic acid contents, chlorophyll contents, leaf pHs, and relative water contents were measured. There was no significant difference in the APTI of Prunus yedoensis and Zelkova serrata between the ozone and control treatments. By contrast, the ozone treatment caused the APTI of Chionanthus retusus to increase and that of Pinus densiflora to decrease compared with the respective controls. These results suggest that the APTI of these tree species exhibit very different responses to ozone. Therefore, more detailed research should be conducted on a range of species in the future.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.6
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• pp.699-709
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• 2017

We measured the grain size, total organic carbon (TOC), total nitrogen (TN), and heavy metals (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, and Zn) in order to understand the spatial distribution and pollution level of organic matter and metals in surface sediment around Goseong Bay, a shellfish farming area, Korea. The surface sediments were composed of finer sediments such as mud and clay. The concentration of TOC, TN, and heavy metals were much higher in the innermost bay than in the mouth and outside of bay. The spatial distribution of organic matter and heavy metals and C/N ratio (5-10) in sediment showed that the organic matter and heavy metals in sediment of the study region were significantly influenced by oceanic origin organic matter and anthropogenic sources, respectively. Based on the results of four assessment techniques (sediment quality guideline, geoaccumulation index, pollution load index, ecological risk index), the sediments around the Goseong Bay were a little polluted for heavy metals and the high metal concentrations in the northern region of bay could adverse impact on benthic organisms in sediment. Thus, the systematic management plan for the improvement of water and sediment environment and the concentrated monitoring of pollutants for sustainable aquaculture and seafood safety around Goseong Bay are necessary in the future.

• ALGAE
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• v.19 no.1
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• pp.15-22
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• 2004

This study investigated the temporal and spatial dynamics of an epilithic algal community in the Hantan River in November 2001, February, May and August 2002. It was identified a total of an epiphlithic 301 taxa which were composed of 275 species, 16 varieties and 10 unidentified species. The standing crops ranged between 598,600-16,525,200 cells $\cdot$ $cm^2$ and showed the temporal and spatial variations, A higher value was found at the lower station than the upper station in winter, but a higher value was found at the upper station than the lower station in summer due to the effects of typhoons. Chlorophyll concentrations ranged between 13.4-304.2 ${\mu}g$ $\cdot$ $cm^2$. Standing crops and chlorophyll showed similar trends in autumn and winter, but temporal dynamics were not apparent in the overgrowth of Lyngbya, Schizothrix and so others in Cyanophyceae in spring and summer. They were composed of species in Chlorophyceae-Bascillariophyceae-Cyanophyceae and no seasonal effect was detected. Low diversity index values probably indicated the effects of environmental stresses (water temperature, flow and current velocity) other than organic pollution. An assessment of organic pollution using epilithic diatoms (DAIpo) showed $\alpha$-oligosaprobic states at the upper- and mid- stations, and $\alpha$-mesosaprobic states at the lower- stations.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.3
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• pp.39-50
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• 2006

In this study, the water quality investigated during 2002s to 2004s for Anyang river and its affluent that was based on biological and chemical methods as well as ecological index of each streams. The improving of water quality and the multiplicity of specious in the most streams except for Anyang, which was due to the improving of water quality and water resource. The seasonal dry states are completely disappeared, but water quality of Anyang main stream was classified as fifth grades water with BIP 8.51~10.00 and BOD 8.16~14.4mg/l in Anyang stream overall. And alpha-mesosaprobic in upper, mid parts and polysaprobic in down parts of Anyang main stream are appeared according to Saprobien system, respectively. The water supply of treated sewage is appeared that upgrading effects of water quality in Anyang main stream and affluents of Anyang city area, but the practical effects of "Saving Anyang River" could not gained because the water quality of other branches in upstream parts than upstream measuring point of Anyang main stream, Wanggok stream Sanbon stream in Gunpo and Eeiwang cities, was not improved.

• Advances in environmental research
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• v.1 no.4
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• pp.277-288
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• 2012

This study investigated exposure to air pollutants in rooms in low-income houses at Shomolu (R1), Mafoluku (R2) and Mushin (R3) in Lagos state. The concentrations of most measured exceeded limits of Illinois Department of Public Health (IDPH) for indoor air quality. Air quality index (AQI) in rooms studied was unhealthy for sensitive people in terms of CO, unhealthy in terms of $SO_2$ and very unhealthy in terms of $NO_2$ while moderate air quality was obtained in terms of $PM_{10}$ in most rooms. High concentrations of carbontetrachloride, formaldehyde and xylene measured could have been responsible for some of the health complaints of the occupants. Factor analysis shows that cooking with kerosene, use of gasoline generator and insecticide were the major contributors to indoor air pollution in these rooms. Therefore, there is need to urgently tackle poverty as all affected by these pollutants were poor who live in substandard houses without kitchens.

• Journal of Korea Multimedia Society
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• v.25 no.2
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• pp.440-449
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• 2022

In recent years, the air pollution and Air Quality Index (AQI) has been a pivotal point for researchers due to its effect on human health. Various research has been done in predicting the AQI but most of these studies, either lack dense temporal data or cover one or two air pollutant elements. In this paper, a hybrid Convolutional Neural approach integrated with recurrent neural network architecture (CNN-LSTM), is presented to find air pollution inference using a multivariate air pollutant elements dataset. The aim of this research is to design a robust and real-time air pollutant forecasting system by exploiting a neural network. The proposed approach is implemented on a 24-month dataset from Seoul, Republic of Korea. The predicted results are cross-validated with the real dataset and compared with the state-of-the-art techniques to evaluate its robustness and performance. The proposed model outperforms SVM, SVM-Polynomial, ANN, and RF models with 60.17%, 68.99%, 14.6%, and 6.29%, respectively. The model performs SVM and SVM-Polynomial in predicting O3 by 78.04% and 83.79%, respectively. Overall performance of the model is measured in terms of Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE) and the Root Mean Square Error (RMSE).