• Journal of Wetlands Research
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• v.20 no.2
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• pp.173-180
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• 2018

The utilization of TOC(Total organic carbon), a new environmental standard, was evaluated for 30 lakes in the Nakdong River Basin, which is used for drinking and agricultural usage. The active use of water resources begins with securing satisfactory water quality. Since this allows people and nature to maintain stability of quality, water quality standards are being tightened to ensure good water quality. In order to improve the pollution level of organic matter in lakes in the living environment, it is important to use the appropriate organic substance index. The relationship between the newly introduced TOC and the existing COD(Chemical oxygen demand) in the targeted lake was positively correlated with the possibility of replacing the TOC with COD. However, the environmental grade standard using TOC is better than the environmental grade standard using COD, so it has the same effect as that of the grade of water quality using TOC as an organic substance factor. This indicates the limitation of TOC to directly replace existing COD when trying to determine or improve the quality level using organic indicators of lakes. Therefore, in order to secure the qualitative safety of the lake, it is required to strengthen environmental standards of TOC in terms of water quality grade. In addition, the correlation between TOC and COD shows a great difference depending on the utilization characteristics of the lake. This requires clear scientific identification, and it requires continuous monitoring of COD that has been used to accumulate indicators of lake organic matter.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2075-2083
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• 2016

The real time IAQ (Indoor Air Quality) management is very important for large buildings and underground facilities such as subways because poor IAQ is immediately harmful to human health. Such IAQ management requires monitoring, prediction and control in an integrated and real time manner. In this paper, we present three PM10 hourly prediction models for such realtime IAQ management as both Multiple Linear Regression (MLR) and Artificial Neural Network (ANN) models. Both MLR and ANN models show good performances between 0.76 and 0.88 with respect to R (correlation coefficient) between the measured and predicted values, but the MLR models outperform the corresponding ANN models with respect to RMSE (root mean square error).

• Journal of Environmental Science International
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• v.27 no.6
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• pp.383-399
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• 2018

In the present study, the community distribution, functional feeding groups, and habitat groups of the benthic macroinvertebrates from Gayasan National Park were investigated at eight different sites from 2015 to 2016. The correlation between habitat altitude and each group type was analyzed statistically. Biodiversity indices, including dominance, diversity, richness, and evenness indices, were calculated. The results showed a total of 4,216 individual benthic macroinvertebrates were collected, including 4 phyla, 6 classes, 16 orders, 40 families, and 100 species. Gammarus sobaegensis was dominant with 0.141% dominance, and the subdominant species was Epeorus nipponicus with 0.088% dominance. The EPT group(Ephemeroptera, Plecoptera and Tricoptera) accounted for 71.00% of the total species and 67.69% of the total individuals. The number of scraper species was highest, and the number of gathering collector individuals was highest among functional feeding groups. The individual number of scrapers(r=-0.358, p < 0.05) and gathering collectors(r=-0.343, p < 0.05) decreased with increasing altitude. The numbers of species and individuals of clingers and sprawlers were highest among the habitat groups. The individual number of clingers(r=-0.547, p < 0.01) and burrowers(r=-0.331, p < 0.05) significantly decreased with increasing altitude. The diversity and richness indices were higher in St. 3 than in the other sites. The dominance index was highest in St. 2, and the evenness index was highest in St. 7. We evaluated the biological water quality with several known methods, and concluded that ESB(Ecological score of benthic macrovertebrates community) and GPI(Group polution index) were more suitable than KSI(Korean saprobic index) and BMI (Benthic macrovertebrate index) to assess the biological water quality of Gayasan mountain stream water.

• Journal of The Korean Society of Grassland and Forage Science
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• v.7 no.3
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• pp.153-156
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• 1987

With a purpose of evaluation rye crop as winter green feed, a cultivar was sown in autumn and harvested at booting, heading, milk, dough and yellow-ripe stages, and processed into silage. The quality of the silage was assessed in terms of ammonia-N, recovery rate in dry matter, pH, and the composition of organic acids. The results obtained are: 1. The recovery rate in dry matter from the silage was the highest when harvested at yellow stage (P<0.01). The ratio of ammonia-N to total-N was low when the rye crop was harvested during milk (9.4%) and dough ( 12.7%) stages (P$NH_3-N$. 3. Silage quality based on the composition of organic acids was highly evaluated when the crop was harvested during milk, and dough stages. 4. Considering both the DM yield and quality of the silage, it was found that rye crop should be harvested at dough stage and ensiled.

• Animal Bioscience
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• v.36 no.9
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• pp.1435-1444
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• 2023

Objective: This study was conducted to evaluate Raman spectroscopy technique as a noninvasive tool to predict meat quality traits on Braford longissimus thoracis et lumborum muscle. Methods: Thirty samples of muscle from Braford steers were analyzed by classical meat quality techniques and by Raman spectroscopy with 785 nm laser excitation. Water holding capacity (WHC), intramuscular fat content (IMF), cooking loss (CL), and texture profile analysis recording hardness, cohesiveness, and chewiness were determined, along with fiber diameter and sarcomere length by scanning electron microscopy. Warner-Bratzler shear force (WBSF) analysis was used to differentiate tender and tough meat groups. Results: Higher values of cohesiveness and CL, together with lower values of WHC, IMF, and shorter sarcomere were obtained for tender meat samples than for the tougher ones. Raman spectra analysis allows tender and tough sample differentiation. The correlation between the quality attributes predicted by Raman and the physical measurements resulted in values of R² = 0.69 for hardness and 0,58 for WBSF. Pearson's correlation coefficient of hardness (r = 0.84) and WBSF (r = 0.79) parameters with the phenylalanine Raman signal at 1,003 cm^-1, suggests that the content of this amino acid could explain the differences between samples. Conclusion: Raman spectroscopy with 785 nm laser excitation is a suitable and accurate technique to identify beef with different quality attributes.

• Journal of Korea Water Resources Association
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• v.45 no.11
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• pp.1157-1168
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• 2012

In this study, we assess changes in water quality trends over time based on certain control measurements in order to identify and analyze the cause of the trend in water quality. The current water pollution in the Nakdong River was analyzed, as it suggests that the significant changes in water quality have occurred in between 2006 and 2010. Based on monthly average data, we have examined for trends of the Nakdong River watershed in water temperature, Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Nitrogen (TN), and Total Phosphorus (TP). Moreover, we have investigated seasonal variation of water quality of sites within the Nakdong River Basin by implementing further analyses such as, Correlation Coefficient, Regression Analysis, Hierarchical Clustering Method, and Time Series Analysis on SPSS. Geology and topography of the watershed, controlled by various conditions such as, climate, vegetation, topography, soil, and rain medium, have been affected by the non-homogeneity. Our study suggests that such variables could possibly cause eutrophication problems in the river. One possible way to overcome this particular problem is to lay up a ship on the river by increasing the nasal flow measurement of the Nakdong River during rainy season. Moreover, the water management requires arranging the measurement of the flow in order to secure the river while the numerous construction projects need to be continuously observed. However, the water is not flowing tributary of the reason for the timing to be flowing in a natural state of river water and industrial water intake because agriculture. Therefore, ongoing research is needed in addition to configuration of all observations.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.461-466
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• 2000

To improve the quality of concrete, we usually consider the reduction of water/cement ratio, the increase of concrete cover depth and the use of mineral admixtures. Reportedly, the use of admixtures make concrete more durable and tighten against water. But, it is needed to study more about the relationship between the admixtures and the chloride ion diffusion. Therefore, in this study, we focused on the chloride ion diffusion properties of the pozzolanic admixtures such as fly-ash, slag and silica fume which are known as being useful on chloride attack resistance when mixed into mortar or concrete. Furthermore, we treed to analyze the correlation between mortar and concrete using the admixture, which is useful for analyzing chloride ion diffusion mechanism.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.525-530
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• 2000

The loss of soil and nutrients from land surfaces to surface water supplies continues to be an important source of nonpoint source pollution. This study was initiate to develop an empirical relationship among the contaminants. SS, COD, T-N, and T-P were collected from agricultural surface water quality studies carried out in Hwasung-Gun, Kyonggi-Do. Correlation analysis, regression analysis, and reliability analysis were conducted. The regression equations were developed between SS and COD, SS and T-P, COD and T-P, and the resulting r$\^$2/ value was over 0.78. The regression equation enables a reasonable prediction of phosphorus concentration and COD concentration for known suspended solid concentration.

• Asian Journal of Turfgrass Science
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• v.26 no.1
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• pp.44-53
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• 2012

As SCB liquid fertilizer (SCB) produced from or out of livestock manure by slurry composting and biofiltration process was applied in golf course, the effect on soil properties and water quality was little investigated. This study was conducted to evaluate the effect of the SCB liquid fertilizer application on environment by monitoring chemical property of soil and water quality of pond as applied chemical fertilizer (CF) and SCB. SCB application rarely contaminated the soil and pond in golf course and decreased organic matter, CEC and Ca in soil and pH and T-N for water quality of pond. In correlation coefficient between soil property parameters, water quality parameters and water quality items, SCB applied in golf course decreased organic matter and CEC in soil and increased SAR in water quality (P<0.01). Nitrogen applied in golf course with SCB or CF was significantly related to T-N in the soil (P<0.01), but not significantly related to T-N in the pond water. These results showed that SCB application little contaminated soil and pond in golf course, and was expected to control of thatch in soil and algae in pond.

• Korean Journal of Remote Sensing
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• v.37 no.6_2
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• pp.1859-1867
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• 2021

This study investigated seasonal characteristics of the particulate matter (PM) in the atmosphere and rainwater quality in Busan, South Korea, and evaluated the seasonal effect of PM₁₀ concentration in the atmosphere on the rainwater quality using multivariate statistical analysis. The concentration of PM in the atmosphere and meteorological observations(daily precipitation amount and rainfall intensity) are obtained from automatic weather systems (AWS) by the Korea Meteorological Administration (KMA) from March 2020 to August 2020. Rainwater samples (n = 216, 13 rain events) were continuously collected from the beginning of the precipitation using the rainwater collecting device at Pukyong National University. The samples were analyzed for pH, EC (electrical conductivity), water-soluble cations(Na⁺, Mg²⁺, K⁺, Ca²⁺, and NH₄⁺), and anions(Cl^-, NO₃^-, and SO₄^2-). The concentration of PM₁₀ in the atmosphere was steadily measured before and after the precipitation with a custom-built PM sensor node. The measured data were analyzed using principal component analysis (PCA) and Pearson correlation analysis to identify relationships between the concentration of PM₁₀ in the atmosphere and rainwater quality. In spring, the daily average concentration of PM₁₀ (34.11 ㎍/m³) and PM_2.5 (19.23 ㎍/m³) in the atmosphere were relatively high, while the value of daily precipitation amount and rainfall intensity were relatively low. In addition, the concentration of PM₁₀ in the atmosphere showed a significant positive correlation with the concentration of water-soluble ions (r = 0.99) and EC (r = 0.95) and a negative correlation with the pH (r = -0.84) of rainwater samples. In summer, the daily average concentration of PM₁₀ (27.79 ㎍/m³) and PM_2.5 (17.41 ㎍/m³) in the atmosphere were relatively low, and the maximum rainfall intensity was 81.6 mm/h, recording a large amount of rain for a long time. The results indicated that there was no statistically significant correlation between the concentration of PM₁₀ in the atmosphere and rainwater quality in summer.