• Mycobiology
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• v.51 no.2
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• pp.109-113
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• 2023

Auricularia is one of the broadly cultivated edible mushrooms in Korea. Most of the Korean Auricularia strains used for cultivation and breeding are known as A. auricula-judae. Recently, this species has been reported to belong to a species complex. Therefore, this study was carried out to genetically clarify the bred and cultivated Korean A. auricula-judae strains. The internal transcribed spacer (ITS) and IGS1 rDNA region sequences were determined from 10 A. auricula-judae strains by PCR and sequencing. Variation in the nucleotide sequence and sequence length of the two rDNA regions were found among the seven A. auricula-judae strains. A maximum-likelihood (ML) phylogenetic tree based on the ITS sequences clearly placed all the 10 Korean A. auricula-judae strains in the A. heimuer clade of the A. auriculajudae complex. A. heimuer is diverged from A. auricula-judae. An ML phylogenetic tree based on the IGS1 sequences revealed the close relationship between Korean A. heimuer strains to Chinese A. heimuer strains. But each strain could be distinguishable by the IGS1 sequence. Furthermore, progeny strains in the seven Korean strains could be differentiated from their parental strains by the IGS1 sequence based phylogenetic tree. Our results are expected to be used to complement the distinction of domestic Auricularia cultivars.

• Journal of Plant Biotechnology
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• v.39 no.1
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• pp.75-80
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• 2012

$Kalopanax$ $pictus$ is a long-lived deciduous perennial tree in the family Araliaceae mainly distributed in the East Asia. In Korea, this species is of ecological and medical importance. Because typical populations of this species are small and distributed in patches, $K.$ $pictus$ has been considered as a narrow habitat species. To understand the genetic diversity and population structure of this species, the sequence variation of the nuclear ribosomal DNA (nrDNA) internal transcribed spacer (ITS) region was analyzed among 18 different $K.$ $pictus$ populations in the present investigation. The nrDNA ITS sequences of Korean populations investigated in this study showed identical of 616 bp in length, and no any nucleotide variation was found in the entire nrDNA ITS region sequence. This result suggested that the $K.$ $pictus$ populations in Korea might belong to the same isolate, and no mutation was found in the nrDNA ITS region. Compared with other known ITS sequence sources from $K.$ $pictus$ populations, only four variable nucleotide sites were found within the entire ITS region. Very narrow genetic diversity appearing in the population level of $K.$ $pictus$ makes us hypothesize that their relatively isolated habitats. The long-lived traits might be one main reason. However, another probability was that the nr-DNA ITS region might be noneffective in classifying populations of $K.$ $pictus$. Thus, to further understand the phylogenetic relationship of $K.$ $pictus$ populations, more samplings should be performed based on more DNA sequences.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1329-1330
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• 2010

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.4
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• pp.402-406
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• 1991

In this paper, we find a set of conditions on weights under which a recursive weighted median filter preserves monotone or localy monotone sequence and under which any input sequence converges to a locally monotone sequence after a finite number of passes.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.5
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• pp.53-63
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• 2008

In this paper, we propose the regional travel time measurement algorithm using the sequence pattern matching to the type of vehicles between the origin of the region and the end of the region, that could be able to overcome the limit of conventional method such as Probe Car Method or AVI Method by License Plate Recognition. This algorithm recognizes the vehicles as a sequence group with a definite length, and measures the regional travel time by searching the sequence of the origin which is the most highly similar to the sequence of the end. According to the assumption of similarity cost function, there are proposed three types of algorithm, and it will be able to estimate the average travel time that is the most adequate to the information providing period by eliminating the abnormal value caused by inflow and outflow of vehicles. In the result of computer simulation by the length of region, the number of passing cars, the length of sequence, and the average maximum error rate are measured within 3.46%, which means that this algorithm is verified for its superior performance.

• Journal of Mushroom
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• v.8 no.1
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• pp.27-32
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• 2010

This study was carried out to analyze the genetic relationships among 22 strains of Sparassis crispa, which were collected from various regions of worldwide. The cleaved amplified polymorphic sequence were obtained from the ribosomal DNA ITS regions of each strain. Based on the sequence analysis, the presence of five different groups were observed. Most strains shared the high nucleotide sequence similarity (about 90%) to each other, except only one strain, KACC50866. Nucleotide sequence similarity of KACC50866 was below 10% to other strains, indicating the genetic relatedness of strain KACC50866 was low compared to other strains. More works such as mitochondria genome analysis should help to determine the precise genetic diversity of S. crispa strains.

• Molecules and Cells
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• v.25 no.4
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• pp.510-522
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• 2008

To construct the molecular systematics of the genus Megoura (Hemiptera: Aphididae), DNA based-identification was performed using four mitochondrial and three nuclear DNA regions: partial cytochrome c oxidase I (COI), partial tRNA-leucine + cytochrome c oxidase II (tRNA/COII), cytochrome b (CytB), partial 12S rRNA + tRNA-valine + 16S rRNA (12S/16S), elongation factor-1 alpha ($EF1{\alpha}$), and the internal transcribed spacers 1 and 2 (ITS1, ITS2). Pairwise sequence divergences between taxa were compared, and phylogenetic analyses were performed based on each DNA region separately, and the combined datasets. COI, CytB, $EF1{\alpha}$, ITS1, and ITS2 were relatively effective in determining species and resolving their relationships. By contrast, the sequences of tRNA/COII and 12S/16S were not able to separate the closely related species. CytB and $EF1{\alpha}$ gave better resolution with higher average sequence divergences (4.7% for CytB, 5.2% for $EF1{\alpha}$). The sequence divergence of COI (3.0%) was moderate, and those of the two ITS regions (1.8% for ITS1, 2.0% for ITS2) were very low. Phylogenetic trees were constructed by minimum evolution, maximum parsimony, maximum likelihood, and Bayesian phylogenetic analyses. The results indicated that the phylogenetic relationships between Megoura species were associated with their host preferences. Megoura brevipilosa and M. lespedezae living on Lespedeza were closely related, and M. nigra, monophagous on Vicia venosa, was rather different from M. crassicauda, M. litoralis, and M. viciae, which are oligophagous on Lathyrus and Vicia. The three populations of M. crassicauda formed a clade separated from M. litoralis and M. viciae. Nevertheless M. litoralis and M. viciae, which are morphologically similar, were not separated due to negligible sequence divergence. We discuss the phylogenetic relationships of the Megoura, and the usefulness of the seven DNA regions for determining the species level phylogeny of aphids.

• Genomics & Informatics
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• v.4 no.4
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• pp.173-181
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• 2006

Pattern finding is one of the important tasks in a protein or DNA sequence analysis. Alignment is the widely used technique for finding patterns in sequence analysis. BLAST (Basic Local Alignment Search Tool) is one of the most popularly used tools in bio-informatics to explore available DNA or protein sequence databases. BLAST may generate a huge output for a large sequence data that contains various sequence patterns. However, BLAST does not provide a tool to summarize and analyze the patterns or matched alignments in the BLAST output file. BLAST lacks of general and robust parsing tools to extract the essential information out from its output. This paper presents a pattern summary system which is a powerful and comprehensive tool for discovering pattern structures in huge amount of sequence data in the BLAST. The pattern summary system can identify clusters of patterns, extract the cluster pattern sequences from the subject database of BLAST, and display the clusters graphically to show the distribution of clusters in the subject database.

• The Mathematical Education
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• v.14 no.1
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• pp.22-26
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• 1975

In this paper, we define a differential module and study its properties. In section 2, as for propositions, Ive research some properties, directsum, isomorphism of factorization, exact sequence of derived modules. And then as for theorem, I try to present the following statement, if the sequence of homomorphisms of differential modules is exact. Then the sequence of homomorphisms of Z(X) is exact, also the sequence of homomorphisms of Z(X) is exact. According to the theorem, as for Lemma, we consider commutative diagram between exact sequence of Z(X) and exact sequence of Z'(X) . As an immediate consequence of this theorem, we obtain the following result. If M is an arbitrary module and the sequence of homomorphisms of the modules Z(X) is exact, then the sequence of their tensor products with the trivial endomorphism is semi-exact.

• Korean Journal of Computational Design and Engineering
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• v.9 no.2
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• pp.158-163
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• 2004

Curve tessellation, which generates a sequence of points from a curve, is very important for curve rendering on a computer screen and for NC machining. For the most case the sequence of discrete points is used rather than a continuous curve. This paper deals with a method of tessellation by calculating the maximal deviation of a curve. The maximal deviation condition is introduced to find the point with the maximal deviation. Our approach has two merits. One is that it guarantees satisfaction of a given tolerance, and the other is that it can be applied in not only a polynomial curve but its offset. Especially the point sequence generated from an original curve can cause over-cutting in NC machining. This problem can be solved by using the point sequence generated from the offset curve. The proposed method can be applied for high-accuracy curve tessellation and NC tool-path generation.