• 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.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1181-1181
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• 2001

Robinson with ${coworkers}^{1}$ have introduced two-state outer-neighbor bonding model to explain the anomalies of water. The studies on the properties of water as a function of temperature and pressure revealed that, unlike other ideas, all $H_2O$ molecules in liquid are tetrabonded. On the average they are forming two different bonding types. One type is the regular tetrahedral water-water bonding similar to that found in the ordinary ice Ih, whereas the other is a more dense nonregular tetrahedral bonding similar to that appearing in the ice II. The transformation between these two bonding forms is evidenced by FT-NIR experiment. The FT-NIR measurements were done for liquid water in the temperature range from $20^{\circ}C$ up to $80^{\circ}C$ in a wide extent of frequencies: 12 000 - 4000 $cm^{-1}$ /. Temperature dependent variations in the volume fraction of these two structures are directly related to the spectral changes. The absorbance variations are explored by means of the two-dimensional correlation spectroscopy (2DCOS), principal component analysis (PCA), curve fitting and second derivatives. The presence of the isosbestic points in a range of the combination and overtone transitions indicates that the experimental spectra are a superposition of two temperature independent components. One component of diminishing intensity with temperature increase, is assigned to a stronger hydrogen bonds occurred in the Ih type, whereas the second component showing an opposite behavior, one can attribute to a weaker H-bonds characteristic for the II type. The understanding of the hydrogen bonding network in the liquid water is very important in interpretation of the interaction between water and protein chain. The two-state model of water surrounding the protein surface could advance an understanding of the hydration process.

• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.596-603
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• 2007

Rapid or on-line coal analysis is of great interest in coal industry as it would allow efficient plant operation. Multivariate analysis has been applied to near-infrared(NIR) spectra coal for investigating the relationship between coal properties(%) (moisture, ash, volatile matter, fixed carbon, carbon, hydrogen, nitrogen, oxygen, sulfur), heating value(kcal/kg) and corresponding near-infrared spectral data. The quantitative analysis was carried out by applying PLS(partial least squares regression) to determine a methodology able to establish a relationship between coal properties and NIR spectral data being applied mathematical pre-treatments for minimizing the physical features of the samples. As a results of the analysis, this technique is able to classify the species of coals and to predict the all coal properties except ash, nitrogen and sulfur. The efficient operation of coal fired power plant is expected owing to real time on-line coal analysis of moisture and heating value.

• Journal of Korean Academy of Nursing
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• v.45 no.3
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• pp.439-448
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• 2015

Purpose: The purpose of this study was to examine validity and reliability of Webel and colleagues'HIV Self-Management Scale when used with a Korean sample. Methods: The original 20-item HIV Self-Management Scale was translated into Korean using translation and back-translation. Nine HIV nurse experts tested content validity. Principal component analysis (PCA) and confirmatory factor analysis (CFA) of data from 203 patients was used to test construct validity. Concurrent validity was evaluated using correlation with patients'self-rating as a "mart patient"measured using a visual analogue scale. Internal consistency was tested by Cronbach' alpha coefficients. Results: All items were rated as having satisfactory content validity. Based on PCA and consideration of conceptual meaning, a three-factor solution was selected, explaining 48.76% of the variance. CFA demonstrated the adequacy of the three-domain structure of the construct HIV self-management: daily self-management health practices, social support and HIV self-management, and chronic nature of HIV self-management. Goodness-of-fit indices showed an acceptable fit overall with the full model (${\chi}^2/df_{(164)}=1.66$, RMSEA=0.06, SRMR=0.05, TLI=0.91, and CFI=0.92). The Korean version of the HIV Self-Management Scale (KHSMS) was significantly correlated with patients'self-rated smart patient (r=.41). The subscale Cronbach' alpha coefficients ranged from .78 to .81; alpha for the total scale was .89. Conclusion: The KHSMS provides a valid and reliable measure of self-management in Korean patients with HIV. Continued psychometric testing is recommended to provide further evidence of validity with this population.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.9
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• pp.1392-1401
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• 2017

In this study, the design methodology of pattern classification is introduced for avoiding faults through partial discharge occurring in the power facilities and local sites. In order to classify some partial discharge types according to the characteristics of each feature, the model is constructed by using the Radial Basis Function Neural Networks(RBFNNs) and Particle Swarm Optimization(PSO). In the input layer of the RBFNNs, the feature vector is searched and the dimension is reduced through Principal Component Analysis(PCA) and PSO. In the hidden layer, the fuzzy coefficients of the fuzzy clustering method(FCM) are tuned using PSO. Raw datasets for partial discharge are obtained through the Motor Insulation Monitoring System(MIMS) instrument using an Epoxy Mica Coupling(EMC) sensor. The preprocessed datasets for partial discharge are acquired through the Phase Resolved Partial Discharge Analysis(PRPDA) preprocessing algorithm to obtain partial discharge types such as void, corona, surface, and slot discharges. Also, when the amplitude size is considered as two types of both the maximum value and the average value in the process for extracting the preprocessed datasets, two different kinds of feature datasets are produced. In this study, the classification ratio between the proposed RBFNNs model and other classifiers is shown by using the two different kinds of feature datasets, and also we demonstrate the proposed model shows superiority from the viewpoint of classification performance.

• Journal of the Korean Society of Tobacco Science
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• v.16 no.2
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• pp.163-171
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• 1994

This experiment was conducted to investigate the discrimination of cigarette brands and the similarity between Korea and America cigarette brands by near infrared spectra. Statistical tools such as principal component analysis (PCA) and mahalanobis distance(M.D) were used. The discrimination rate of the Korea and the America cigarette brands, determined by position number which was calculated with PCA and M.D, was 94% and 87%, respectively. The spectra of the 10 America cigarette brands were selected by averaging 5 sample spectra for each brand and another 5 spectra for each brand were investigated to use as the sample spectra. Comparing the sample spectra with the selected spectra by M.D using 410-1090 nm, 1110-1850 nm and 1970-2490 nm wavelength, the discrimination rate which was determined by the closest M.D between the sample and the selected spectra was 100% when each spectra was investigated on the same time. But the discrimination rate decreased 50% when the sample and the selected spectra were investigated on the different time. Excluding 1970-2490 nm wavelength, the discrimination rate increased up to 90% when the sample and the selected spectra were investigated on the different time. Comparing the spectra of Korea cigarette brands with those of America cigarette brands by M.D using only 410-1090 nm and 1110-1850 nm wavelength, the spectra of Expo(G) was similar to Winston, Vantage(U.L) and Benson & hedges(M.), the spectra of Hanaro(D) was similar to Carrel, Winston(L), Vantage(U.L), \Vantage and Carrel(L), the spectra of Hanaro(L) was similar to Winston(L) , Carton, Vantage and Carmel(L) and the spectra of Pinetree was similar to Kent, Kool, Kent(G.L), Merit and Benson & hedges(L), respectively. Key Words : NIRS, cigarette brands discrimination

• Korean Journal of Ichthyology
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• v.23 no.1
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• pp.37-45
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• 2011

Seasonal variation in species composition and abundance of fish larvae assemblages in the south-western Jinhae Bay were investigated monthly in 2009. During the study period, 49 larvae species belonging to 24 families were collected. The dominant species were Clupea pallasii, Hexagrammos otakii, Konosirus punctatus, Engraulis japonicus, Parablennius yatabei, and Omobranchus elegansei. These six species accounted for 92.7% of the total number of individuals collected. The number of species, number of individuals, and species diversity indices fluctuated with the seasons. The peak number of species and individuals occurred in July and January, respectively. Principal component analysis(PCA) and correlation analysis showed that variation in monthly water temperature could act as an indicator of seasonal variation in community structure and abundance of the dominant species; in particular, those of C. pallasii, H. otakii, E. japonicus and P. yatabei corresponded with the water temperature.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.2
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• pp.183-191
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• 2018

In this study a traffic volume dependent displacement estimation model for Gwangan Bridge was developed using bridge monitoring big data. Traffic volume data for four different vehicle types and the vertical displacement data in the central position of the Gwangan Bridge were used to develop and validate the estimation model. Two statistical estimation models were developed using multiple regression analysis (MRA) and principal component analysis (PCA). Estimation performance of those two models were compared with actual values. The results show that both the MRA and the PCA based models are successfully estimating the vertical displacement of Gwangan Bridge. Based on the results, it is concluded that the developed model can effectively be used to predict the traffic volume dependent displacement behavior of Gwangan Bridge.

• Korean Journal of Plant Taxonomy
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• v.44 no.2
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• pp.100-110
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• 2014

Saussurea pseudogracilis Kitam. is characterized by its slender leaves, small involucre and small number of involucral bracts compared to Saussurea gracilis Maxim. But some taxonomists insist that it is hard distinguih S. pseudogracilis from S. pseudogracilis. We tried to discern taxonomic identification of S. pseudogracilis by measuring and analyzing 45 qualitative characters and 42 quantitative characters on 165 specimen. S. pseudograilis was not distinguished from S. gracilis not only by qualitative characters but also by quantitative characters even on statistical analysis(PCA). Therefore, S. pseudogracilis is not independent taxonomic species and it is proper to consider S. pseudogracilis as a synonym of S. gracilis.

• Journal of Environmental Science International
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• v.19 no.7
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• pp.861-869
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• 2010

The present study aims to evaluate the characteristics of atmospheric polycyclic aromatic hydrocarbons (PAHs) pollution in roadside and residential areas of two Korean metropolitan cities (Seoul and Incheon) and a background area (Seokmolee). This purpose was established by analyzing temporal and spacial concentration distribution of total and 7 individual PAHs, which were extracted from ambient particulate matters, and by utilizing a multivariate statistical method (principal component analysis, PCA) for the qualitative determination of potential PAH sources. Target PAHs included benzo(a)anthracene (BaA), benzo(a)pyrene (BaP), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (BkF), chrysene (Chr), dibenzo(a,h)anthracene (DahA), and indeno(1,2,3-cd)pyrene (IcdP). For all surveyed sites, the concentrations of total PAHs were higher in winter season than in other seasons. However, the concentrations of individual PAHs varied with surveyed sites. In both residential and roadside sites of Seoul and Incheon, BbF revealed the highest atmospheric levels. For all 7 target PAHs, the ambient concentrations were higher in Seoul and Incheon than in a background area (Seokmolee). In both residential and roadside areas, the concentrations of 4 target PAHs (BaA, BbF, BkF, DahA) were higher in Incheon than in Seoul. However, both the residential and roadside Chr concentrations were comparable in Seoul and Incheon. In addition, the residential IcdP concentrations were higher in Incheon than in Seoul, whereas the roadside concentrations were higher in Seoul. The roadside and residential BaP concentrations exhibited the reverse result to the IcdP concentrations. An PCA analysis suggested that atmospheric PAHs in both residential and roadside areas would be due to combined effects of several potential sources such as gasoline- and diesel-fueled vehicles, coal/oil combustion, and waste incineration.