• Communications of the Korean Mathematical Society
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• v.12 no.1
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• pp.37-43
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• 1997

Some formulas of the genus numbers and the ambiguous ideal class numbers of function fields are given and these numbers are shown to be the same when the extension is cyclic.

• Korean Journal of Microbiology
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• v.22 no.3
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• pp.197-205
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• 1984

After the previous paper, this chromosomal studies on the fungi were dealt with 17 species in genus of Rhizopus. The results are sumarized as the followings; The haploid chromosome number of 17 species were confirmed as of 6(Rh. oligosporus), 8(Rh. homothallicus, Rh. liquefaciens, Rh. shanghaiensis, Rh, acetorinus), 12(Rh. microsporus, Rh. pseudochinensis, Rh, rhizopodiformis, Rh, thermosus, and Rh. kazanensis), 14(Rh. stolonifer), and 16(Rh. suinus), respectively. Referring to the above fact and the previous paper, it is strongly presumed that the basic chromosome number of Rhizopus are 4.

• The Korean Journal of Zoology
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• v.39 no.2
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• pp.207-214
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• 1996

Five call types of the genus Hyla in habitats around South Korea were classified according to some attributes of their advertisement calls (note duration, note intenral, dominant frequency, sonagram patterns. Among the call types, the E-type was more distinctive than the other call types in that it had a metal sound and much longer note duration and note intenral. This result indicated that some divergence had occurred in the advertisement call of the genus Hylo, though this was found in alimited number of regions and its occurrence was small.

• Korean Journal of Microbiology
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• v.20 no.3
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• pp.134-146
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• 1982

This experiment was designed to elucidate the life cycle of 7 species (Rh.nigricans, Rh. delemar, Rh.oryzae, Rh.acidus, Rh.tritici, Rh. formosaensis and Rh. japonicus) in genus Rhizopus isolated from Korean soil, so as to seize the appropriate stage for detecting their chromosomal number and nuclear size under the method of thin layer slide culture using modified Rogers(1965a) medium. The results are summarized as the folowings ; 1. The haploid chromosome number are found 16 in Rh. japonicus are 8, respectively. 2. Comparing the 7 species of Rhizopus with each other, it may be concluded that the basic haploid chromosome number of genus Rhizopus distributed in Korean soil are 8 and that Rh. nigricans is double of the basic hapolid chromosome number (n = 16). Besides them, the other two species (Rh. tritici and Rh. formosaensis) are believed aneuploids.

• Journal of The Korean Astronomical Society
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• v.46 no.3
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• pp.125-131
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• 2013

We present the relation between the genus in cosmology and the Betti numbers for excursion sets of three- and two-dimensional smooth Gaussian random fields, and numerically investigate the Betti numbers as a function of threshold level. Betti numbers are topological invariants of figures that can be used to distinguish topological spaces. In the case of the excursion sets of a three-dimensional field there are three possibly non-zero Betti numbers; ${\beta}_0$ is the number of connected regions, ${\beta}_1$ is the number of circular holes (i.e., complement of solid tori), and ${\beta}_2$ is the number of three-dimensional voids (i.e., complement of three-dimensional excursion regions). Their sum with alternating signs is the genus of the surface of excursion regions. It is found that each Betti number has a dominant contribution to the genus in a specific threshold range. ${\beta}_0$ dominates the high-threshold part of the genus curve measuring the abundance of high density regions (clusters). ${\beta}_1$ dominates the genus near the median thresholds which measures the topology of negatively curved iso-density surfaces, and ${\beta}_2$ corresponds to the low-threshold part measuring the void abundance. We average the Betti number curves (the Betti numbers as a function of the threshold level) over many realizations of Gaussian fields and find that both the amplitude and shape of the Betti number curves depend on the slope of the power spectrum n in such a way that their shape becomes broader and their amplitude drops less steeply than the genus as n decreases. This behaviour contrasts with the fact that the shape of the genus curve is fixed for all Gaussian fields regardless of the power spectrum. Even though the Gaussian Betti number curves should be calculated for each given power spectrum, we propose to use the Betti numbers for better specification of the topology of large scale structures in the universe.

• Communications of the Korean Mathematical Society
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• v.20 no.2
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• pp.259-273
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• 2005

In this paper we determine all subfields with genus one of cyclotomic function fields over rational function fields explicitly.

• Bulletin of the Korean Mathematical Society
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• v.46 no.5
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• pp.917-930
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• 2009

We find all distinct representatives of isomorphism classes of genus-3 pointed trigonal curves and compute the number of isomorphism classes of a special class of genus-3 pointed trigonal curves including that of Picard curves over a finite field F of characteristic 2.

• Proceedings of the Korean Aquaculture Society Conference
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• 2004.05a
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• pp.510-511
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• 2004

A terrestrial cave snail (Gastropoda: Subulinidae), Sinistras chois n. gen., n. sp., from the Gungi-cave in Jeju Island, South Korea represents a monotypic genus, and is proposed as a new genus in the family Subulinidae. Diagnostic features of the genus include a sinistral shell, that has a minute-sized, elongate conic-shaped, apical microsculpture with low tubercles. The chromosome number and karyotype are 2n=56 and 8M+15SM+5ST, respectively.

• Microbiology and Biotechnology Letters
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• v.34 no.4
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• pp.335-337
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• 2006

Glycerol-spore formation of wild myxobacteria isolated in Korea has been tested. One third of the wild myxobacterial isolates belonged to the genus Myxococcus and Corallococcus produced a large number of glycerol-spores in the presence of glycerol or dimethyl sulfoxide. However, two third of the other wild myxobacterial isolates belonged to the genus Myxococcus and Corallococcus produced a negligible number of spores under the same condition. In addition, the myxobacteral isolates belonged to the other genus, such as Stigmatella, Archangium, and Cystobacter, failed to produce a noticeable number of glycerol-spores.

• Korean Journal of Plant Taxonomy
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• v.48 no.3
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• pp.201-205
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• 2018

Carex L. (Cyperaceae) is the largest angiosperm genus in the temperate zones with more than 2,000 species worldwide. Unusual chromosome structures, called holocentric chromosomes, have been postulated to contribute to species diversity in the genus. In Korea, this genus has the greatest number of species, but chromosome information as it pertains to the taxa is mostly unknown. Here, we report meiotic chromosome numbers of five Carex taxa in Korea. The following observations are made: Carex jaluensis Kom. ($n=27_{II}$, $28_{II}$, $29_{II}$, $30_{II}$), C. japonica Thunb. ($n=28_{II}$, $29_{II}$), C. planiculmis Kom. ($n=30_{II}$), C. miyabei Franch. ($n=33_{II}$, $36_{II}$), C. neurocarpa Maxim. ($n=51_{II}$, $53_{II}$, $54_{II}$). Except for C. planiculmis, all of the species exhibit variations in chromosome numbers within individuals and/or taxa. The findings with regard to chromosome number diversity in Carex suggest that chromosome number variation (aneuploidy, agmatoploidy and/or symploidy) plays an important role in the richness of the species in the genus. Further cytological investigations are needed for a better understanding of sedge diversity in Korean flora.