• Journal of Korean Critical Care Nursing
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• v.12 no.1
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• pp.1-12
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• 2019

Purpose : It is widely accepted that addressing multiple symptoms together is the preferred approach in assessment and intervention and results in reduced negative patient outcomes. Yet, there are few studies examining symptom clusters and their impacts on quality of life longitudinally in patients after heart valve surgery. Methods: A total of 101 patients were recruited from a tertiary hospital and were administered questionnaires (at 3, 6, and 10 weeks after the surgery) assessing participants' characteristics, cardiac symptoms, and quality of life. Factor analysis was used to identify symptom clusters. Hierarchical multiple linear regression was used to predict quality of life. Results: Participants were predominantly 70-years old or more with a mean age of 64.34. The two symptom clusters at 3 weeks after the surgery with education, gender, and occupation accounted for 76.3% of variance in quality of life. Conclusion: Symptom clusters containing various physical and psychological symptoms in patients after the surgery affected quality of life, and the relationship was significant at 3 weeks after the surgery. Because symptom clusters were identified in all three recovery periods, nurses need to acknowledge these clusters, rather than each symptom separately, and to utilize these in providing care and education and in promoting quality of life in these patients.

• Development and Reproduction
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• v.23 no.3
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• pp.297-304
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• 2019

The higher fragment sizes (>2,100 bp) are not observed in the two C. spp. populations. The six oligonucleotides primers OPA-11, OPB-09, OPB-14, OPB-20, OPC-14, and OPC-18 were used to generate the unique shared loci to each tonguesole population and shared loci by the two tonguesole populations. The hierarchical polar dendrogram indicates two main clusters: Gunsan (GUNSAN 01-GUNSAN 11) and the Atlantic (ATLANTIC 12-ATLANTIC 22) from two geographic populations of tonguesoles. The shortest genetic distance displaying significant molecular difference was between individuals' GUNSAN no. 02-GUNSAN no. 01 (genetic distance=0.038). In the long run, individual no. 02 of the ATLANTIC tonguesole was most distantly related to GUNSAN no. 06 (genetic distance=0.958). These results demonstrate that the Gunsan tonguesole population is genetically different from the Atlantic tonguesole population. The potential of PCR analysis to identify diagnostic markers for the identification of two tonguesole populations has been demonstrated. As a rule, using various oligonucleotides primers, this PCR method has been applied to identify polymorphic/specific markers particular to species and geographical population, as well as genetic diversity/polymorphism in diverse species of organisms.

• Natural Product Sciences
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• v.17 no.2
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• pp.147-159
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• 2011

A high-performance liquid chromatography-electrospray ionization-tandem mass spectrometric method was developed to determine simultaneously eight marker constituents of Forsythiae fructus, and subsequently applied it to classify its two botanical origins. The marker compounds of Forsythia suspensa were phillyrin, pinoresinol, phillygenin, lariciresinol and forsythiaside; those of F.viridissima were arctiin, arctigenin and matairesinol. Separation of the eight analytes was achieved on a phenyl-hexyl column (150${\times}$2.0 mm i.d., 3 ${\mu}M$) using gradient elution with the mobile phase: (A) 10% acetonitrile in 0.5% acetic acid, (B) 40% aqueous acetonitrile. A few fragment ions specific to the types of lignans, among the product ions generated by collisonally induced dissociation (CID) of molecular ion clusters, such as [M-H]$^-$ or [M+OAc]$^-$ were used not only for fingerprinting analysis but for the quantification of each epimer by using multiple-reaction monitoring mode. It was shown good linearity ($r^2{\geq}$ 0.9998) over the wide range of all analytes; intra- and inter-day precisions (RSD, %) were within 9.14% and the accuracy ranged from 84.3 to 115.1%. The analytical results of 40 drug samples, combined with multivariate statistical analyses - principal component analysis (PCA) and hierarchical cluster analysis (HCA) - clearly demonstrated the classification of the test samples according to their botanical origins. This method would provide a practical strategy for assessing the authenticity or quality of the herbal drug.

• Analytical Science and Technology
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• v.33 no.2
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• pp.98-107
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• 2020

Methamphetamine (MA) is currently the most abused illicit drug in Korea. MA is produced by chemical synthesis, and the final target drug that is produced contains small amounts of the precursor chemicals, intermediates, and by-products. To identify and quantify these trace compounds in MA seizures, a practical and feasible approach for conducting chromatographic fingerprinting with a suite of traditional chemometric methods and recently introduced machine learning approaches was examined. This was achieved using gas chromatography (GC) coupled with a flame ionization detector (FID) and mass spectrometry (MS). Following appropriate examination of all the peaks in 71 samples, 166 impurities were selected as the characteristic components. Unsupervised (principal component analysis (PCA), hierarchical cluster analysis (HCA), and K-means clustering) and supervised (partial least squares-discriminant analysis (PLS-DA), orthogonal partial least squares-discriminant analysis (OPLS-DA), support vector machines (SVM), and deep neural network (DNN) with Keras) chemometric techniques were employed for classifying the 71 MA seizures. The results of the PCA, HCA, K-means clustering, PLS-DA, OPLS-DA, SVM, and DNN methods for quality evaluation were in good agreement. However, the tested MA seizures possessed distinct features, such as chirality, cutting agents, and boiling points. The study indicated that the established qualitative and semi-quantitative methods will be practical and useful analytical tools for characterizing trace compounds in illicit MA seizures. Moreover, they will provide a statistical basis for identifying the synthesis route, sources of supply, trafficking routes, and connections between seizures, which will support drug law enforcement agencies in their effort to eliminate organized MA crime.

• Journal of Korean Society of Forest Science
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• v.102 no.3
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• pp.407-414
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• 2013

This study was conducted to classify forest cover types using the multivariate statistical analysis in the natural forest of western Mt. Jiri. On the basis of the vegetation data by point quarter sampling, the adopted analytical methods were species-area curve (SAC), hierarchical cluster analysis (HCA), indicator species analysis (ISA), and multiple discriminant analysis (MDA). SAC selected the outlier tree species which was likely to have no influence on the classification of forest cover types, excluded from all analytical process. Based on forest vegetative information, HCA classified the study area into 2 to 10 clusters and ISA indicated that the optimal number of clusters were seven. MDA was taken to test the clusters that classified with HCA and ISA. The seven clusters were classified appropriately as overall classification success were 91.3%. The classified forest cover types were named by the ratio of the dominant species in the upper layer of each cluster. They were (1) Quercus mongolica Pure forest, (2) Mixed mesophytic forest, (3) Q. mongolica - Q. serrata forest, (4) Abies koreana - Q. mongolica forest, (5) Fraxinus mandshurica forest, (6) Q. serrata forest, and (7) Carpinus laxiflora forest.

• Journal of Digital Convergence
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• v.17 no.6
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• pp.27-33
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• 2019

The purpose of this study was to explore the moderating effect of learning strategy levels on the relationship between academic grit and career development competence perceived by high school students. The sample for this study comprised 573 high school students, and data analysis was conducted mainly using reliability analysis, correlation analysis, K-mean cluster analysis, hierarchical regression analysis. The results of the study showed that the learning strategy levels moderated the relationship between academic grit and career development competence. This study suggest it is necessary to provide grit enhancement programs coupled with learning strategy levels in order to facilitate career development competence. The future studies need to explore the literature review for logical relationship between academic grit and career development competence, the qualitative approach for drawing on the theoretical models among the related variables, and the relational research to explore mediating or moderating effect of the individual backgrounds and related variables on the relationship between academic grit and career development competence.

• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.25-33
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• 2019

Lactobacillus rhamnosus BFE5264, isolated from a Maasai fermented milk product ("kule naoto"), was previously shown to exhibit bile acid resistance, cholesterol assimilation, and adhesion to HT29-MTX cells in vitro. In this study, we re-annotated and analyzed the previously reported complete genome sequence of strain BFE5264. The genome consists of a circular chromosome of 3,086,152 bp and a putative plasmid, which is the largest one identified among L. rhamnosus strains. Among the 2,883 predicted protein-coding genes, those with carbohydrate-related functions were the most abundant. Genome analysis of strain BFE5264 revealed two consecutive CRISPR regions and no known virulence factors or antimicrobial resistance genes. In addition, previously known highly variable regions in the genomes of L. rhamnosus strains were also evident in strain BFE5264. Pairwise comparison with the most studied probiotic strain L. rhamnosus GG revealed strain BFE5264-specific deletions, probably due to insertion sequence-mediated recombination. The latter was associated with loss of the spaCBA pilin gene cluster and exopolysaccharide biosynthetic genes. Comparative genomic analysis of the sequences from all available L. rhamnosus strains revealed that they were clustered into two groups, being within the same species boundary based on the average nucleotide identities. Strain BFE5264 had a sister group relationship with the group that contained strain GG, but neither ANI-based hierarchical clustering nor core-gene-based phylogenetic tree construction showed a clear distinctive pattern associated with the isolation source, implying that the genotype alone cannot account for their ecological niches. These results provide insights into the probiotic mechanisms of strain BFE5264 at the genomic level.

• Journal of Korean Society for Atmospheric Environment
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• v.10 no.E
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• pp.332-342
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• 1994

Hierarchical cluster and factor analyses were used to identify various influences on free tropospheric air samples at Mauna Loa Observatory in Hawaii during MLOPEX. The cluster analysis separated thirteen chemical and meteorological variables into three characteristic groups (1)clean air, (2)anthropogenically influenced air, (3)marine and volcanic influenced air. The cluster analysis results compared well with those of factor analysis. Six independent components were identified in factor analysis. We have related these components to (1)volcano influenced air, (2)stratosphere-like air, (3)boundary-layer air with recent anthropogenic influence, (4)photochemical haze, (5)marine boundary- layer air, and (6)modified marine tropospheric air. Excluding local influence, we could calculate the nighttime free tropospheric values for $O_3$(41$\pm$10 ppbv), HN $O_3$(94$\pm$45 pptv), N $O_3$$^{[-10]}$ (16$\pm$10 ppbv), S $O_4$$^{[-10]}$ (60$\pm$0 pptv), N $H_4$$^{＋}$(71$\pm$6 pptv), N $a^{＋}$(5$\pm$1 pptv), PAN(13$\pm$9 pptv), MeN $O_3$(3.5$\pm$1.5 pptv), 2-butyl N $O_3$(0.6$\pm$0.1 pptv), $H_2O$$_2$(1015$\pm$44 pptv), $C_2$C $l_4$(3.3$\pm$0.1 pptv), condensation nuclei(249$\pm$13c $m^{-3}$), and dew point(-8.5$\pm$5.3$^{\circ}C$) during this experiment..

• International Commerce and Information Review
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• v.14 no.3
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• pp.539-558
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• 2012

The purpose of this study is examining the differences of mobile SNS's service quality, which consists data quality and system quality, among the groups that are classified by commitment and customer loyalty. For the experimental analysis, the frequency analysis was performed for general characteristics of sample. The variables were selected by factor analysis that also prove the validity of variables. The value of Cronbach's alpha was calculated to check the reliability of variables. In addition, the group was determined by the both hierarchical and hierarchical cluster analysis, then ANOVA was performed to test the hypotheses that there are differences of mobile SNS's service quality, among the groups that are classified by commitment and customer loyalty. The results of this study support that there are differences among the groups toward mobile SNS's service quality and also shows the more commitment and loyalty group is the higher recognition of mobile SNS's service quality. Thus, the companies have to realize that mobile SNS is very important key factor to success in rapidly changing business environment. In conclusion, the companies implement different customized strategy for the different group and develop the contents and the applications to maximize the commitment and loyalty of for the mobile SNS users.

• Science of Emotion and Sensibility
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• v.19 no.4
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• pp.55-70
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• 2016

It has been suggested that few studies were completed on psychological aspect of coffee drinking behavior though coffee researches have been mainly focused on marketing or business purposes. In this study, fifteen university students were participated to a group interview for concept mapping analysis asking about their meaning and purpose of coffee drinking behavior. Sixty nine statements were extracted from the interview, and categorized into seven clusters using multi dimensional scaling analysis and hierarchical cluster analysis. Seven clusters were Personal method of getting the desired physical effect, As a method of social activities, Method to get psychological consolation, Drink for spending time and using space, Habitual drink and use of caffeine's effect, Enjoying coffee's various characteristic and attraction, and Enjoying coffee's various characteristic and attraction. Two factors were identified based on these clusters such as internal-external motivation to drink coffee and emotional-physical effect of coffee. Participants ranked their priority of those clusters; the cluster of "Drink for spending time and using space" was first ranked. Limitations and suggestions for future research were also discussed.