• Journal of the Korean earth science society
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• v.41 no.3
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• pp.211-221
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• 2020

This study classified outer-ring galaxies using 25,308 galaxies within z=0.05 from the SDSS DR7, which are larger than R_pet>6 arcsec and whose minor-to-major axis ratio (b/a)<0.6. We selected 531 galaxies that have ring-like structures by visual inspection of the color images of 25,308 galaxies; these galaxies with ring-like structures served as a primary sample from which we selected 90 outer-ring galaxies. The final sample of 69 outer-ring galaxies was selected by examining the photometric properties of the candidate galaxies. Their properties were determined by conducting surface photometry on their u, g, r, i, and z images. The frequency of the outer-ring galaxies was found to be 0.3% of the local galaxies. We examined the environment of the outer-ring galaxies using two measures of environment, namely, the projected distance to the nearest-neighbor galaxy and the local background density. We did not observe any notable difference between outer-ring and other galactic environments.

• Journal of the Korean earth science society
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• v.32 no.1
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• pp.152-157
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• 2011

Lg amplitude decrease $Q^{-1}$ becomes very important when harzadous earthquakes occurred in neighbor nations such as Japan and China because the Lg phase is the largest seismic phase in Korea. The values of Lg $Q^{-1}$ are correlated with seismic activities from the RTSM for IRIS data with long pair distance of stations and events. The Japanese paths crossing the East Sea (Sea of Japan) show high $Q^{-1}$ values related with seismicity and oceanic crust. The paths of Shanghai having the moderate seismicity show the second highest values followed by the Japanese region, while the paths between Manchuria and the Korean Peninsula exhibit low values associated with the low seismicity of the regions.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.4 s.310
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• pp.50-57
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• 2006

In Electronic Commerce, the latest most of the personalized recommender systems have applied to the collaborative filtering technique. This method calculates the weight of similarity among users who have a similar preference degree in order to predict and recommend the item which hits to propensity of users. In this case, we commonly use Pearson Correlation Coefficient. However, this method is feasible to calculate a correlation if only there are the items that two users evaluated a preference degree in common. Accordingly, the accuracy of prediction falls. The weight of similarity can affect not only the case which predicts the item which hits to propensity of users, but also the performance of the personalized recommender system. In this study, we verify the improvement of the prediction accuracy through an experiment after observing the rule of the weight of similarity applying Vector similarity, Entropy, Inverse user frequency, and Default voting of Information Retrieval field. The result shows that the method combining the weight of similarity using the Entropy with Default voting got the most efficient performance.

• Journal of Broadcast Engineering
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• v.17 no.6
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• pp.990-1003
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• 2012

In this paper, the possibility and necessity of the digital broadcasting propulsion in AM and FM is presented based on DRM and DRM+ transmission modes, They are the members of series technological family in digital radio development. As the frequency utilization, the application of DRM+ is flexible in any mode such as IN-BAND or OUT-OF-BAND. When the digital audio broadcasting is planned at LOW-VHF bandwidth such as TV channel No.5 and NO.6 being adjacent to FM band and OUT-Of-BAND DRM+ technology is applied, there is no collision and jamming. Particularly, in the IN-BAND Hybrid mode, it is mentioned that there was the difficulty problem for multiple SFN transmitters uses. Not like the IN-BAND mode the OUT-OF-BAND mode lets multiple transmitters, because neighbor transmitters do not interfere each other. Digital transmitter can be combined with the existing FM transmitter. The intensity of power and size of area can be easily determined according to local broadcasters' condition. And the OUT-OF-BAND mode is advantageous for AM/FM integration in digital radio receiver manufacturing, which makes the conversion schedule much shorter.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.10
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• pp.1369-1378
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• 2006

This is the first study in which genetic variability and relationships of a large number of Japanese chicken breeds were revealed along with those of several foreign breeds by using microsatellite DNA polymorphisms. Twenty-eight breeds (34 populations) of native Japanese chickens and seven foreign breeds or varieties were analyzed. The mean number of alleles per locus, the proportion of the polymorphic loci, and the expected average heterozygosity ranged from 1.75 to 4.70, from 0.55 to 1.00, and from 0.21 to 0.67, respectively. Microsatellite alleles being unique to a particular population were detected in some populations. The $D_A$ genetic distance between populations was obtained from allele frequency for every pair of the populations to construct a neighbor-joining tree. According to the phylogenetic tree, excluding a few exceptions, native Japanese chicken breeds and foreign breeds were clearly separated from each other. Furthermore, the tree topology divided native Japanese chickens into four main classes, which was almost in accordance with the classification based on body morphology; that is, (1) Cochin type, (2) Malay type, (3) layer type, and (4) intermediate type between Malay and layer types. This is the first finding for native Japanese chickens.

• The Journal of Korean Academic Society of Nursing Education
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• v.6 no.2
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• pp.262-275
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• 2000

This study was done to describe the health promoting behavior and the quality of life among climacteric women and to identify the factors affecting the performance in health promoting behavior and the level of quality of life among climacteric women. The subjects of this study were 171 women(40 to 60 years old). The sample data were collected using a convenient sampling method, collected from August 10th to September 20th, 2000. The instruments for this study were the health promoting behavior scale(Park, 1995), the quality of life scale(No, 1988). Frequency, percentage, t-test, ANOVA, Pearson's correlation with SPSS program were used to analyze the data. The results of the study were as follows; 1) The average score of the performance in the health-promoting behavior variables was 2.594. The variable with the highest degree of performance was the sanitary environment, whereas the one with the lowest degree was the professional health maintenance. 2) The average score of the level in the quality of life variables was 3.069. The variable with the highest degree was the relationship with neighbor, whereas the one with lowest degree was the economic life factor. 3) Performance in the health- promoting behavior was positively related to the level in the quality of life(r=0.54, P=0.001). 4) A significant difference was demonstrated between educational level, income, perceived health status and health-promoting behavior. 5) A significant difference was demonstrated between perceived health status and quality of life.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.471-476
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• 2007

Little is known about the origin and genetic diversity of swamp buffaloes in China. To obtain more knowledge on genetics of the water buffalo in China, the complete mitochondrial D-loop sequences of 30 samples from 6 native types were investigated. The results revealed 12 mitochondrial haplotypes with 50 polymorphic sites. Among these polymorphic sites, there were 49 transitions and 1 transversion. The average nucleotide diversity and haplotype diversity estimated from mtDNA D-loop region in 6 Chinese water buffalo types were 0.00684 and 0.798, respectively, showing rather abundant mitochondrial genetic diversity. The Neighbor-Joining (NJ) tree of mtDNA of Chinese water buffaloes was constructed according to the 12 haplotypes. The NJ tree indicated two lineages being designated lineage A and lineage B, in which lineage A was predominant, and lineage B was at low frequency. The new lineage B was first discovered and defined in 6 Chinese water buffalo types. These results showed that two different maternal lineages were involved in the origin of domestic swamp buffaloes in China and the lineage B was probably an introgression from Southeast Asian buffaloes.

• Genomics & Informatics
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• v.9 no.4
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• pp.181-188
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• 2011

In planning a model-based phylogenic study for highly related ethnic data, the SNP marker number is an important factor to determine for relationship inferences. Genotype frequency data, utilizing a sub sampling method, from 63 Pan Asian ethnic groups was used for determining the minimum SNP number required to establish such relationships. Bootstrap random sub-samplings were done from 5.6K PASNPi SNP data. DA distance was calculated and neighbour-joining trees were drawn with every re-sampling data set. Consensus trees were made with the same 100 sub-samples and bootstrap proportions were calculated. The tree consistency to the one obtained from the whole marker set, improved with increasing marker numbers. The bootstrap proportions became reliable when more than 7,000 SNPs were used at a time. Within highly related ethnic groups, the minimum SNPs number for a robust neighbor-joining tree inference was about 7,000 for a 95% bootstrap support.

• Animal cells and systems
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• v.13 no.4
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• pp.419-427
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• 2009

The Minke whale, Balaenoptera acutorostrata, is the smallest baleen whale in the suborder Mysticeti. Because this species inhabits coastal areas, it became a main target species of coastal small-type whaling in the North Atlantic and the Northwest Pacific Oceans, and the species' population size dramatically decreased because of over-exploitation. As a result, the International Whaling Commission declared a global moratorium on whaling and launched the development of a management procedure for protecting the whales. Morphological studies, whaling history analysis, and genetic studies conducted mainly by Japanese scientists showed the existence of one unique "E" stock that inhabits the waters around the Korean peninsula and mixes with the "O" stock in the southern part of the Sea of Okhotsk. We used the mitochondrial DNA control region polymorphism of 348 Minke whales bycaught or stranded in Korean waters from 30 October 1998 to 25 June 2005 to assess the whale population structure by year. The frequency of the 10 major haplotypes from the 40 identified haplotypes was not significantly different among groups, suggesting that a subpopulation was not present. A comparison of the genetic distances calculated with Tamura-Nei's method showed that the distances between groups were lower than those within groups, which suggests that there was no genetic difference in the Minke whale populations. The Fst comparison between groups and the phylogenetic tree constructed using the unweighted pair group method with arithmetic mean (UPGMA) and Neighbor Joining (NJ) method also detected no obvious sub-stock structure.

• Journal of dental hygiene science
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• v.20 no.1
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• pp.44-50
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• 2020

Background: Smartphones are a modern necessity. While they are convenient to use, smartphones also have side effects such as addiction. This study assessed the relationship between smartphone use, a part of everyday life in modern society, and oral health. Methods: An analysis was conducted using 2017 Korea Youth Risk Behavior Web-based Survey data. The propensity score estimation algorithm used logistic regression and 1:1 matching algorithm using nearest-neighbor matching. After matching, a total of 15,032 participants were classified into two groups containing 7,516 teenagers each who did and did not use smartphones, respectively. Results: Comparison of oral health behaviors according to smartphone use revealed a statistically significant difference in the frequency of tooth brushing per day, use of oral hygiene products, intake of foods harmful to oral health, and experience of oral health education (p<0.05). The factors affecting oral pain experience of adolescents were examined. Compared to male participants, female participants had an odds ratio of 1.627 for oral pain (p<0.05). According to the household income level, compared to the group with higher income, the group with lower income showed higher oral pain experience (p<0.05). Oral pain experience was 1.601 times more frequent among teenagers using smartphones (p<0.05). Conclusion: The results of this study indicated that use of smartphones by adolescents affected their oral health. These findings indicate the need for improved oral health management through the use of effective school oral health programs and individual counseling by oral health professionals, promotion of information dissemination through public media, and development of prevention strategies.