• Bulletin of the Korean Mathematical Society
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• v.56 no.2
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• pp.535-547
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• 2019

In this paper, by using the lower bound of linear forms in logarithms of Matveev and the theory of continued fractions by means of a variation of a result of Dujella and $Peth{\ddot{o}}$, we find all generalized Fibonacci numbers which are Pell numbers. This paper continues a previous work that searched for Pell numbers in the Fibonacci sequence.

• Molecules and Cells
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• v.26 no.6
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• pp.566-575
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• 2008

Twenty-five chipmunk species occur in the world, of which only the Siberian chipmunk, Tamias sibiricus, inhabits Asia. To investigate mitochondrial cytochrome b sequence variations and population structure of the Siberian chipmunk in northeastern Asia, we examined mitochondrial cytochrome b sequences (1140 bp) from 3 countries. Analyses of 41 individuals from South Korea and 33 individuals from Russia and northeast China resulted in 37 haplotypes and 27 haplotypes, respectively. There were no shared haplotypes between South Korea and Russia - northeast China. Phylogenetic trees and network analysis showed 2 major maternal lineages for haplotypes, referred to as the S and R lineages. Haplotype grouping in each cluster was nearly coincident with its geographic affinity. In particular, 3 distinct groups were found that mostly clustered in the northern, central and southern parts of South Korea. Nucleotide diversity of the S lineage was twice that of lineage R. The divergence between S and R lineages was estimated to be 2.98-0.98 Myr. During the ice age, there may have been at least 2 refuges in South Korea and Russia - northeast China. The sequence variation between the S and R lineages was 11.3% (K2P), which is indicative of specific recognition in rodents. These results suggest that T. sibiricus from South Korea could be considered a separate species. However, additional information, such as details of distribution, nuclear genes data or morphology, is required to strengthen this hypothesis.

• Parasites, Hosts and Diseases
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• v.42 no.4
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• pp.159-167
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• 2004

Sequences of the complete protein-coding portions of the mitochondrial (mt) genome were analysed for 6 species of cestodes (including hydatid tapeworms and the pork tapeworm) and 5 species of trematodes (blood flukes and liver- and lung-flukes). A near-complete sequence was also available for an additional trematode (the blood fluke Schistosoma malayensis). All of these parasites belong to a large flatworm taxon named the Neodermata. Considerable variation was found in the base composition of the protein-coding genes among these neodermatans. This variation was reflected in statistically-significant differences in numbers of each inferred amino acid between many pairs of species. Both convergence and divergence in nucleotide, and hence amino acid, composition was noted among groups within the Neodermata. Considerable variation in skew (unequal representation of complementary bases on the same strand) was found among the species studied. A pattern is thus emerging of diversity in the mt genome in neodermatans that may cast light on evolution of mt genomes generally.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.8
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• pp.1085-1090
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• 2009

There are currently five primary breeds of Chinese gamecock, the Henan, Luxi, Tulufan, Xishuangbanna andZhangzhou. Though there is historical evidence of cockfighting in China dating as far back as 2,800 years, the origin and genetic relationships of these breeds are not well understood. We used sequence variation from the mtDNA cytb gene and control region (1,697 bp) to examine the domestication history and genetic relationship of the Chinese gamecock. From 75 samples (14-16 per breed) we found 34 haplotypes, and 45 variable nucleotides. Phylogenetic reconstruction indicated multiple origins of the gamecock breeds. The breeds in the north and center of China, Tulufan, Luxi and Henan, clustered together in a haplogroup and may have the same ancestor. However the southern breeds, Zhangzhou and Xishuangbanna clustered into two isolated haplogroups, suggesting another two origins of Chinese gamecock. Meanwhile, extensive admixture was also found because samples from different breeds, more or less, were always grouped together in the same clades. Based on these results, we discuss the possibilities of multiple origins of gamecock breeds, from both ancestral gamecocks as well as other domestic chickens and red jungle fowl.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7091-7094
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• 2013

DNA repair capacity is crucial in maintaining cellular functions and homeostasis. However, it can be altered based on DNA sequence variations in DNA repair genes and this may lead to the development of many diseases including malignancies. Identification of genetic polymorphisms responsible for reduced DNA repair capacity is necessary for better prevention. Homologous recombination (HR), a major double strand break repair pathway, plays a critical role in maintaining the genome stability. The present study was performed to determine the frequency of the HR gene XRCC3 Exon 7 (C18067T, rs861539) polymorphisms in Saudi Arabian population in comparison with epidemiological studies by "MEDLINE" search to equate with global populations. The variant allelic (T) frequency of XRCC3 (C>T) was found to be 39%. Our results suggest that frequency of XRCC3 (C>T) DNA repair gene exhibits distinctive patterns compared with the Saudi Arabian population and this might be attributed to ethnic variation. The present findings may help in high-risk screening of humans exposed to environmental carcinogens and cancer predisposition in different ethnic groups.

• Journal of Nutrition and Health
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• v.30 no.3
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• pp.349-359
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• 1997

This study was designed to study sources of variability(subjects, day by day, season, day of week, sequence, number of repeated days, compliance etc.) in multiple 24-hour dietary recall method. Dietary intakes of college women in Seoul were obtained using 24-hour dietary recalls, consecutive 7 days, 4 times for 1 year. The result of this study shows that 1) the reproducibility of multiple 24-hour recalls is low(intraclass correlation coefficient<0.3), 2) the intraindividual variations of all nutrients are more than 80%, 3) the major components of variation are interindividual vriability and intraindividual variability(within person variability and methodologic error). There were small but statistically significant season and compliance effects. 4) the ratio within-person varation to between-person variation for absolute and transformed nutrient intakes except some nutrients such as vitamin A, vitamin C, energy from protein and fat etc, was less than 1.7 the minimum numbers of days needed in 24-hour dietary recalls to estimate usual intake for this group were 1 to 21 days. And the numbers of days needed to get the usual intake of an individual varied among individuals and within individuals for different nutrients, ranged from 1 days for log carbohydrate(% energy) to 470 days for Na. 6) There were greater than 0.7 correlation coefficients between the average nutrient intakes of 12 days and intakes of 28 days. Therefore, it was desirable to take the 24-hour recall more than 12 times, repeating 3 days every season.

• Publications of The Korean Astronomical Society
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• v.15 no.spc1
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• pp.133-145
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• 2000

Symbiotic stars are known as binary systems with both cool and hot components with enshrounding nebulous gas. The cool component, M-type giant, is presumably loosing its mass into a hot white or main sequence companion star through the inner Lagrangian point. The lines emit from the ionized nebulous region around the hot star while the mass loss or accretion activity is believed to be the main cause of sudden variation of the continuum and line fluxes. We selected 17 symbiotics for which the emission line fluxes were measured from the IUE SWP, LWR data, to find variability of spectrum. We also investigated the periodic variation of emissions or eclipsing effect from the IUE lines. All of our symbiotics show very high electron densities in the emission regions. For other optical symbiotics, the observations had been carried in 1999 with BOAO mid-resolution spectrometer. We classified symbiotics based on their outburst activities, or emission line characteristics, i.e., $OVI{\lambda}6830.\;The\;OVI{\lambda}6830$ emission lines are also found in S-type symbiotics, which have been known as charateristics of D-types.

• Journal of Digital Contents Society
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• v.14 no.1
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• pp.117-124
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• 2013

This paper suggests the robust method of extraction for moving objects in illumination variation by using image sequence from an immovable camera. The most difficult part of the implication is the effect by illumination and noise. The object area is hardly estimated when the dusky area occurs in illumination variation by time change. This thesis describes the extraction of moving objects employed by Gaussian mixture model which is noise robust measure. Also, the report suggests the elimination method of illumination part in input image by the representative illumination image which is defined to minimize the illumination influence.

• Journal of the Semiconductor & Display Technology
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• v.12 no.2
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• pp.27-32
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• 2013

Shape From Focus (SFF) is a passive optical technique to recover 3D structure of an object that utilizes focus information from 2D images of the object taken at different focus levels. Mostly, SFF methods use a single focus measure to compute image focus quality of each pixel in the image sequence. However, it is difficult to recover accurate 3D shape using a single focus measure, as different focus measures perform differently in diverse conditions. In this paper, a nonlinear Total Variation (TV) based approach is proposed for 3D shape recovery. To improve the result of surface reconstruction, several initial depth maps are obtained using different focus measures and the resultant 3D shape is obtained by diffusing them through TV. The proposed method is tested and evaluated by using image sequences of synthetic and real objects. The results and comparative analysis demonstrate the effectiveness of our method.

• Animal cells and systems
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• v.4 no.1
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• pp.23-30
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• 2000

Horizontal starch gel electrophoresis for 29 populations (n=543) of the wrinkled frog, Rana rugosa, from Korea and Japan was peformed to assess the degree of genic variation and genetic diversity, and to understand the biogeographic pattern of distribution and speciation. A sum of 22 presumptive loci was screened from 17 enzymes and general proteins. Four loci, Aco, Est-3, Me-2, and Pgm, demonstrated high levels of polymorphism. The degree of average genetic variation of R. rugosa was P=22.7% (9.1-40.9%), Ho=0.086 (0.048-0.165) and He=0.090 (0.042-0.168). In the south-eastern region of the Korean peninsula (Chongsong, Yongchon, Ulsan, Kyongju, Pohang, yongdok and Ulchin), a few unique alleles in the Mpi locus were detected and their biogeographic implications were considered. The degree of genetic differentiation among the Korean populations was moderate (S=0.900), whereas the degree of genetic diversity between Korean and Japanese populations was notably high (S=0.687, D=0.293). This result corresponds with the data obtained by the mitochondrial cytochrome b gene sequence (Lee et al., 1999) suggesting that the Korean and Japanese R. rugosa might have evolved a specific level of genetic differentiation since their geographic isolation.