• Journal of Sensor Science and Technology
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• v.21 no.1
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• pp.1-6
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• 2012

Using a current-mode multiple reset, a current-to-voltage(I-V) converter with a wide dynamic range was produced. The converter consists of a trans-impedance amplifier(TIA), an analog-to-digital converter(ADC), and an N-bit counter. The digital output of the I-V converter is composed of higher N bits and lower bits, obtained from the N-bit counter and the ADC, respectively. For an input current that has departed from the linear region of the TIA, the counter increases its digital output, this determines a reset current which is subtracted from the input current of the I-V converter. This current-mode reset is repeated until the input current of the TIA lies in the linear region. This I-V converter is realized using 0.35 ${\mu}m$ LSI technology. It is shown that the proposed I-V converter can increase the maximum input current by a factor of $2^N$ and widen the dynamic range by $6^N$. Additionally, the I-V converter is successfully applied to a photometric sensor.

• Journal of Ecology and Environment
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• v.30 no.4
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• pp.331-340
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• 2007

We examined the evolutionary and ecological processes shaping current geographical distributions of a Korean wood-eating cockroach species, Cryptocercus kyebangensis. Our research aims were to understand evolutionary pattern of DNA sequences, to construct genetic network of Cryptocercus kyebangensis local populations and to understand evolutionary and ecological processes shaping their current geographical distribution patterns via DNA sequence information and genetic networks, using sequence data of two genes (ITS-2 and AT region) from local populations of C. kyebangensis. The results suggest that the ITS-2 and AT region are appropriate molecular markers for elucidating C. kyebangensis geographic patterns at the population level. The MSN-A based on the ITS-2 showed two possible routes, the Hwaak-san and Myeongji-san route and the Seorak-san and Gyebang-san route, for migration of ancestral C. kyebangensis into South Korea. The MSNs (MSN-A and -B) elucidate migration routes well within South Korea, especially the route of Group I and Group II.

• Journal of Life Science
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• v.11 no.2
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• pp.74-80
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• 2001

The nucleotide sequences of the internal transcribed spacer regions (ITS1 and ITS2) of ribosomal DNA (rDNA), and the 5.85 rRNA gene, have been determined for 13 strains of dinoflagellates in order to analyze the phylo-genetic relationship. The DNA sequences contained considerable variation in the ITS regions, but little in the 5.85 rDNA. In addition, the ITS1 was more variable than the ITS2 in all species examined. The nucleotide length of this region varied from 519 bp to 596 bp depending on the taxa. The investigated taxa were divided into three large groups based on the ITS length, i. e., a group with short ITS region (A. fraterculus and Alexandrium sp.), a with ITS region group (P. micans, P. minimum and P. triestinum) and a with ITS region group (G. impudicum, C. polykrikoides, G. sanguineum, G. catenatum and H. triquetra). The relationship between nucleotide length of ITS1 and that of ITS2 was negative, whereas G+C content and nucleotide length showed positive correlation. In phylogenetic analyses producing NJ trees, the topology was similar cluster and clearly divided the taxa into three groups based on 5.8S rDNA that were similar to those based on morphological characteristics. In particular, G. impudicum was more closely related to G. catenatum than to C. polykrikoides using phylogenetic analysis. From this study, we chew that the length of ITS region contributes to discriminate Korean harmful algal species and ITS analysis is a useful method for resolving the systematic relationships of dinoflagellates.

• Archives of Pharmacal Research
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• v.29 no.1
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• pp.88-95
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• 2006

Analysis of molecular nature of mitochondrial DNA (mtDNA) could be powerful marker for anthropological studies of modern populations. While population genetic studies on mtDNA have been reported for several ethnic groups, no such study has been documented for the Korean population. We surveyed mtDNA polymorphisms in the HVS I of noncoding D-loop region and its upstream region from 430 unrelated healthy Korean population by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and direct sequencing analysis. PCR product with 2,790 bp spanning the specific mtDNA region (mt13715-16504) was subjected to RFLP analysis using 6 restriction enzyme (Hinf I, Hae III, Alu I, Dde I, Mbo I, Rsa I). On the PAUP analysis of PCR-RFLP results, 38 mtDNA haplotypes (Hap 1-38) were detected in the Korean populations, which were classified into 11 haplogroups (Grp 1-11) of related haplotypes encompassing all 38 haplotypes. In comparison of sequencing data with Anderson's reference sequence, the transition type was more prevalent than the transversion type. Insertions or deletions were not found. In addition, three of the polymorphic sites (A16240C, A16351G, G16384A) in HVS-I region are determined newly. The polymorphic sites were distributed randomly in the region, though the frequency at each site was variable. Thus, this research might be required for the genealogical study of Orientals.

• Journal of Microbiology
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• v.39 no.4
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• pp.265-272
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• 2001

Variation within the intergenic spacer(IGS) of the ribosomal DNA gene for twenty-two strains of E. oxysporum and its formae speciales was examined by PCR, couped with RELP analysis. The length of the amplified IGS region was about 2.6 kb in all strains except F.oxysporum f. sp. cucumer-inum from Korea and F. oxysporum f. sp. niveum. Those two strains were 2.5 kb long. Restriction digestion of IGS-RELP regions by Eco RI, NruI, HincII, SAlI, SmaI, BalIi, HindIII, XhoI and KpnI gave rise to nine IGS hapoltypes among all strains. Cluster analysis based on the presence of absence of comigrating restriction reagments show the two groups based on 44% genetic similarity. These results demonstrated that analysis of IGS showed some difference within and between F. oxysporum formae speciales.

• Journal of Korean Society on Water Environment
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• v.23 no.4
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• pp.434-439
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• 2007

Amended Water Quality Environment Preservation Law enacted that the areas where nonpoint pollution is serious can be designated as Nonpoint Source Management Region. According to Section 54 of Water Quality Environment Preservation Law, corresponding watersheds are areas where runoff from nonpoint pollution source may deteriorate river and lake water quality, residents' health and property, and ecosystem. The criteria are as followings; i) where nonpoint source contribution result in or will result in significant ecological destruction, iii) national or local industrial complexes and cities having population greater than one million where nonpoint source managements are necessary, iv) where specific measurement is necessary because of its geological and stratigraphic characteristics. In this research, detailed designation criteria was developed reflecting current nonpoint source management situation and its discharge characteristics. Depending on the result, target regions were also suggested. In additions, it will be desirable that the target regions are prioritized considering institutional execution availability, stakeholder's agreement, and connection with existing nonpoint source pollution management measures.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.40.1-40.1
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• 2021

Hydrogen is the most abundant element in the universe, which is, in the cosmological context, attributed to its simplest structure consisting of a proton and an electron. Hydrogen interacts with an electromagnetic wave in astrophysical environments. Rayleigh scattering refers to elastic scattering, where the frequencies of the incident and scattered photons are the same. Rayleigh and resonance scattering is a critical role study Lyman Alpha objects in the early universe. The scattering causes the frequency and spatial diffusion of Lyα. In the case of Raman scattering, the energies of the incident and scattered photons are different. The photons near Lyβ convert to the optical photons near Hα through Raman scattering. The photon scattered by atomic hydrogen can carry both of the properties of the H I region and the emission region. I adopt a Monte Carlo approach to investigate the formation of the various spectral line features through Rayleigh and Raman scattering in highly thick media of atomic hydrogen. In this thesis, I present my works on radiative transfer involving the scattering processes between far UV photon and atomic hydrogen. I introduce scattering processes with atomic hydrogen and the spectral, spatial, and polarized information originating from the scattering.

• Journal of Mushroom
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• v.7 no.3
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• pp.98-104
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• 2009

Phylogenetic relationships of Hypsizygus mamoreus and Lyophyllum decastes artificial cultivated using ITS sequences and RAPD polymorphism have been analyzed. Based on ITS region sequences of 14 strains, we could divide into 2 group as group1 to Hypsizygus mamoreus and the control isolated group2 to Lyophyllum decastes were identified as the same species. Restrict analysis of rDNA ITS region which was amplified by PCR, 14 collected strains could be classified into 4 clusters. There was approximately 58% genetic similarity between cluster I(SPA 100, 101, 102) and cluster II(SPA 200, 208 and SPA 201, 202), 41% between cluster III(SPA 104, 103, 203) and cluster IV(SPA 204, 206, 207, 205) by BLAST analysis. RAPD polymorphisms were used to analyze the species diversity of artificially cultivated Lyophyllum decastes SPA 202. As a result, similarity between SPA 202 and SPA 203 was 75%, at the same time, similarity between SPA 202 and Pleurotus eryngii SPA 103 and SPA 104 was 65%.

• Food Science and Biotechnology
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• v.17 no.4
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• pp.888-891
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• 2008

Twenty-three fungal strains were isolated from meju that had originated from the Sunchang province, the famous location for making fermented soybean foods in Korea. The restriction fragment length polymorphism (RFLP) of the internal transcribed spacer (ITS) region of the rDNA (ITS-RFLP) was applied to differentiate the isolated fungal strains. First, the ITS region by polymerase chain reaction (PCR) with specific primers was amplified and then cleaved the products with different restriction enzymes. Cleavage of the amplified fragments with the restriction enzymes AluI, HaeIII, HhaI, and TaqI revealed extensive polymorphisms. The ITS-RFLP results highly correlated with ITS sequence analysis. All of the 23 fungal strains were classified into 5 groups by ITS-RFLP analysis. Aspergillus oryzae was the major fungal strain isolated from Sunchang meju (12 out of 23), while Aspergillus fumigatus was the next most frequently isolated strain (7 out of 23). In contrast, it was found that Fusarium asiaticum, Aspergillus sydowii, and Arthrinium sp. were the minor fungal strains in meju.

• The Plant Pathology Journal
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• v.22 no.1
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• pp.36-45
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• 2006

Twenty isolates of Didymella bryoniae were isolated from infected cucurbit plants in various growing areas of southern Korea in 2001 and 2002. Random Amplified Polymorphic DNA (RAPD) group [RG] I of D. bryoniae was more virulent than RG IV to watermelon. Virulence of the RG I isolate was strong to moderate to cucumber, whereas that of the RG IV varied from strong, moderate to weak. Two hundred seventy-three amplified fragments were produced with 40 primers, and were analyzed by a cluster analysis using UPGMA method with an arithmetic average program of NTSYSPC. At the distance level of 0.7, two major genomic DNA RAPD groups were differentiated among 20 isolates. The RG I included 7 isolates from watermelon and one isolate from melon, whereas the RG IV included 12 isolates from squash, cucumber, watermelon and melon. Amplification of internal transcribed spacer (ITS) region and small subunit rRNA region from the 20 isolates yielded respectively a single fragment. Restriction pattern with 12 restriction enzymes was identical for all isolates tested, suggesting that variation in the ITS and small subunit within the D. bryoniae were low. Amplification of the genomic DNAs of the tested isolates with the sequence characterized amplified regions (SCAR) primer RG IF-RG IR specific for RG I group resulted in a single band of 650bp fragment for 8 isolates out of the 20 isolates. Therefore, these 8 isolates could be assigned into RG I. The same experiments done with RG IIF-RG IIR resulted in no amplified PCR product for the 20 isolates tested. An about 1.4 kb-fragment amplified from the RG IV isolates was specifically hybridized with PCR fragments amplified from genomic DNAs of the RG IV isolates only, suggesting that this PCR product could be used for discriminating the RG IV isolates from the RG I isolates as well other fungal species.