• Title/Summary/Keyword: L-diversity

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Reevaluation of Isolation and Identification of Gram-positive Bacteria in Kimchi (김치에 서식하는 Gram 양성세균의 분리 및 동정의 재평가)

  • 임종락;박현근;한홍의
    • Korean Journal of Microbiology
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    • v.27 no.4
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    • pp.404-414
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    • 1989
  • Attempts were made to isolate and identify Gram-positive or lactic acid bacteria in Kimchi fermentation. Species diversity depended on isolation media and temperatures, and diversity tended to be reduced with decrease of temperature. MRS and KM (natural medium prepared from Kimchi materials) were suitable respectively for isolation and present number of species. Identification of isolates was performed by dichotomous identification schemes arranged on the basis of Bergey's manual of Systematic Bacteriology (1986). Gram-positive bacteria isolated at different temperatures (5, 15, $25^{\circ}C$) were 5 species of Leuconostoc, 4 species of Streptococcus, 3 species of Pediococcus, 2 species of Bacillus and 18 species of Lactobacillus. Species with high frequency of appearance were Lactobacillus plantarum, Streptococcus raffinolactis, Leuconostoc mesenteroides subsp. mesenteroides at $25^{\circ}C$, L. plantarum, Lactobacillus fructosus, L. mesenteroides subsp. mesenteroides at $15^{\circ}C$ and L. mesenteroides subsp. mesenteroides, Leuconosotoc paramesenteroides, Lactobacillus maltaromicus at $15^{\circ}C$. In general, Kimchi fermentation was achieved by Lactobacillus spp. (59.7% frequency) at $25^{\circ}C$ and Leuconostoc spp. (65.2% frequency) at $5^{\circ}C$. Pediococcus cerevisiae and Streptococcus faecalis which have been so far known as bacteria of Kimchi fermentation were not isolated.

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Genetic Diversity and Population Structure of Peanut (Arachis hypogaea L.) Accessions from Five Different Origins

  • Zou, Kunyan;Kim, Ki-Seung;Lee, Daewoong;Jun, Tae-Hwan
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.65 no.4
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    • pp.447-456
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    • 2020
  • Peanut is an allotetraploid derived from a single recent polyploidization. Polyploidization has been reported to have caused significant loss in genetic diversity during the domestication of cultivated peanuts. Single nucleotide polymorphism (SNP)-based markers such as cleaved amplified polymorphic sequences (CAPS) derived from next-generation sequencing (NGS) have been developed and widely applied for breeding and genetic research in peanuts. This study aimed to identify the genetic diversity and population structure using 30 CAPS markers and 96 peanut accessions from five different origins. High genetic dissimilarities were detected between the accessions from Korea and those from the other three South American origins generally regarded as the origin of peanuts, while the accessions from Brazil and Argentina presented the lowest genetic dissimilarity. Based on the results of the present study, accessions from Korea have unique genetic variation compared to those from other countries, while accessions from the other four origins are closely related. Our study identified the genetic differentiation in 96 peanut accessions from five different origins, and this study also showed the successful application of SNP information derived from re-sequencing based on NGS technology.

Genetic diversity and phenotype variation analysis among rice mutant lines (Oryza sativa L.)

  • Truong, Thi Tu Anh;Do, Tan Khang;Phung, Thi Tuyen;Pham, Thi Thu Ha;Tran, Dang Xuan
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.22-22
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    • 2017
  • Genetic diversity is one of fundamental parameters for rice cultivar improvement. Rice mutants are also a new source for rice breeding innovation. In this study, ninety-three SSR markers were applied to evaluate the genetic variation among nineteen rice mutant lines. The results showed that a total of 169 alleles from 56 polymorphism markers was recorded with an average of 3.02 alleles per locus. The values of polymorphism information content (PIC) varied from 0.09 to 0.79. The maximum number of alleles was 7, whereas the minimum number of alleles was 2. The heterozygosity values ranged from 0.10 to 0.81. Four clusters were generated using the unweighted pair group method with arithmetic mean (UPGMA) clustering. Fourteen phenotype characteristics were also evaluated. The correlation coefficient values among these phenotye characteristics were obtained in this study. Genetic diversity information of rice mutant lines can support rice breeders in releasing new rice varieties with elite characterisitics.

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Genetic Variation in Korean Populations of Wild Radish, Raphanus sativus var.hortensis f. raphanistroides (Brassicaceae)

  • Hur, Man Kyu
    • Journal of Plant Biology
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    • v.38 no.4
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    • pp.329-336
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    • 1995
  • Raphanus sativus L. var. hortensis f. raphanistroides (wild radish: Brassicaceae), a herbaceous perennial, occurs only on beaches in East Asia. Genetic diversity and population structure of seven Korean populations were investigated using starch gel electrophoresis. Although the Korean populatins are small, isolated with patchy distribution, the population maintain a moderate level of genetic diversity; the mean percentage fo polymorphic loci was 51.4%, mean number of alleles per locus was 1.84, and mean expected heterozygosity was 0.116. A combination of animal-outcrossing breeding system, wide geographical distribution, restricted ecological distribution, and a propensity for high fecundity may in part be explanatory factors contributing the moderate level of genetic diversity within populations. An overall excess of homozygotes relative to Hardy-Weinberg expetations (mean FISa=0.116) indicates that consanguineous mating occur within wild radish populations, leading to a family structure within a circumscribed area. Although population of wild radish experience a limited gene flow, only 5% of the total genetic variation found in Korean wild radish populations examined is due to differences among populations (mean GST=0.052). This value is considerably lower than the mean values of species with similar life history and ecological characteristics. However, significant differences were found in allele frequencies between populations for all polymorphic loci (P<0.01). It is supposed that directional selection toward genetic uniformity (similar gene frequencies) in a relatively homogenous habitat is thought to be operated among Korean wild radish populations.

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Vegetation Structure of Mountain Ridge in Midongsan, Chungcheongbuk-do

  • You, Ju-Han
    • Korean Journal of Plant Resources
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    • v.21 no.3
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    • pp.216-221
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    • 2008
  • The Purpose of this study was to offer the raw data for drawing up the conservation plan by analysing natural vegetation in Midongsan, Chungcheongbuk-do, Korea. The period of survey was from July to October, 2004 and the size of plot was 100$m^2$. In the results of analyzing the physical environments, the range of altitude was 303${\sim}$550m and soil pH was 5.4${\sim}$6.8. The angle of slope was 3${\sim}$57% and topographical factor was composed of ridgeline. In the results of analyzing a importance percentage, the dominant species in tree layer, Pinus rigida, P. densiflora, Quercus mongolica, Q. variabilis and Q. acutissima, P. rigida, Q. mongolica, Q. acutissima, Platycarya strobilacea and Q. variabilis in subtree layer, Rhododendron mucronulatum, Symplocos chinensis for pilosa, Lindera obtusiloba, L. erythrocarpa, Rhus trichocarpa and Weigela subsessilis in shrub layer. In the results of species diversity index, species diversity (H') was from 1.2401 to 2.5540, maximum species diversity (H'max), from 1.9459 to 2.8904, evenness (J'), from 0.5644 to 0.8836, dominance (D), from 0.1164 to 0.4356.

Performance Improvement of Convolutional Coded Multi-Carrier DS-CDMA System Using Hybrid SC/MRC-Lc/L Diversity (하이브리드 SC/MRC-Lc/L 다이버시티 수신시 콘볼루션 부호화 된 Multi-Carrier DS-CDMA 시스템의 성능 개선)

  • 김영철;노재성;조성언;조성준
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.05a
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    • pp.535-539
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    • 2002
  • 본 논문에서는 Hybrid SC/MRC-Lc/L 다이버시티 수신 기법과 콘볼루션 부호화 기법을 각각 또는 함께 이용할 때의 Multi-Carrier DS-CDMA 시스템의 성능 개선을 구하였다. 우선 다중경로 페이딩 및 다중접속간섭의 영향을 분석하고, 두 기법에 의한 성능 개선 정도를 구하여 비교, 분석하였다. Hybrid SC/MRC-Lc/L 수신에서는 각각의 반송파에 대하여 상관을 취하고 상관기 출력들 중에서 가장 큰 신호성분을 Lc개만큼 선택하여 최대비 합성하며, 콘볼루션 부호화는 다중경로 페이딩 및 다중접속간섭에 의하여 발생된 오류를 정정 및 검출한다. 분석 결과, 콘볼루션 부호화 기법을 채용함으로서 성능이 현저하게 개선되는데, 부호이득과 전력제한 사이에 trade off를 고려하여 부호화 율( r)을 선택할 필요가 있다는 것과 하이브리드 SC/MRC-L$^{c}$ /L 수신에서는 입력 다이버시티 가지의 수 (L)가 많을수록 선택의 폭이 넓어지며, 적절한 숫자의 다이버시티 가지의 선택이 시스템의 복잡성과 성능 대 비용 등을 결정한다는 것을 알 수 있었다.

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An Effective Anonymization Management under Delete Operation of Secure Database (안전한 데이터베이스 환경에서 삭제 시 효과적인 데이터 익명화 유지 기법)

  • Byun, Chang-Woo;Kim, Jae-Whan;Lee, Hyang-Jin;Kang, Yeon-Jung;Park, Seog
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.17 no.3
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    • pp.69-80
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    • 2007
  • To protect personal information when releasing data, a general privacy-protecting technique is the removal of all the explicit identifiers, such as names and social security numbers. De-identifying data, however, provides no guarantee of anonymity because released information can be linked to publicly available information to identify them and to infer information that was not intended for release. In recent years, two emerging concepts in personal information protection are k-anonymity and $\ell$-diversity, which guarantees privacy against homogeneity and background knowledge attacks. While these solutions are signigicant in static data environment, they are insufficient in dynamic environments because of vulnerability to inference. Specially, the problem appeared in record deletion is to deconstruct the k-anonymity and $\ell$-diversity. In this paper, we present an approach to securely anonymizing a continuously changeable dataset in an efficient manner while assuring high data quality.

Performance Analysis or MC / DS CDMA System with Hybrid SC / MRC Diversity over Multi-path Fading Channels (다중경로 페이딩 채널에서 Hybrid SC/MRC 기법이 적용된 MC / DS CDMA 시스템의 성능분석)

  • 김원섭;박진수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.7A
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    • pp.748-755
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    • 2004
  • In this paper, the hybrid SC/MRC technique was applied to the MC/DS-CDMA system in the Nakagami-m multi-path fading environment. The applied scheme was compared with other cases when the MRC technique was applied and then performances were analyzed. The result of analysis showed that the performance of the applied system, whose number of branches (L) for the input diversity of each carrier wave was 3 and かme selected number of branches ( Lc) was 2, was better than that of the MRC technique when the Lc of the MRC technique was 2. The performance of the applied system was lower than that of the MRC technique, then the Lc of the MRC technique was 3. However, as the fading index was lowered, which means the telecommunication environment deteriorated, the performance of the hybrid SC/MRC-(2/3) diversity technique when Lc of MRC technique was 3, was almost the same as that of the MRC technique. The hybrid SC/MRC-(2/3) diversity technique shows a similar performance to that of the MRC technique, when the Lc of the MRC technique was 4. Therefore, it was confirmed that the MC/DS-CDMA system could reduce complexity and achieve similar performance to that of the MRC by applying the hybrid SC/MRC technique, which utilized the advantages of the SC technique and high performance of the MRC scheme, rather than the MRC diversity technique that requires bit synchronization, frequency of fading, and phase synchronization for every diversity branch.

First Record of Two Gobiid Fishes, Luciogobius elongatus, L. platycephalus (Perciformes: Gobiidae) from Korea

  • Cho, Hyun-Geun;Choi, Seung-Ho
    • Animal Systematics, Evolution and Diversity
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    • v.30 no.1
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    • pp.22-25
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    • 2014
  • Two species of small gobiid fishes genus Luciogobius, i.e., L. elongatus, L. platycephalus were described as the first records from Korea based on specimens collected from gravel beaches of Gijang-gun, Busan-si, Korea. Luciogobius elongatus is distinguished from congeners by very elongated and naked body, 42-44 vertebrae, 6-7 dorsal soft rays, and no free rays on pectoral fin, and L. platycephalus is characterized by having very depressed head, naked body, 40-41 vertebrae, 10-11 dorsal soft rays, and pectoral fin with only upper 2-4 free rays. We propose the new Korean name "Ga-neun-mi-kkeun-mang-dug", "Nab-jak-mi-kkeun-mang-dug" for L. elongatus and L. platycephalus, respectively.

Record of Lispe consanguinea (Diptera: Muscidae), New to Korea

  • Bae, Eunji;Suh, Sang Jae
    • Animal Systematics, Evolution and Diversity
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    • v.37 no.1
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    • pp.15-18
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    • 2021
  • Flies of the genus Lispe are large, dark gray, and have well-developed palpi. Most Lispe species are found in damp sandy and muddy environments, such as borders of marshes, seashore areas, swamps, lakes, ponds, streams, and rice paddy fields. Both adults and larvae are predators of various small aquatic insects. Previously, five species of Lispe had been identified in Korea: L. assimilis Wiedemann, 1824, L. litorea Fallén, 1825, L. orientalis Wiedemann, 1824, L. patellitarsis Becker, 1914, and L. tentaculata (DeGeer, 1776). In this paper, we record a sixth Lispe species, L. consanguinea Loew, 1858, for the first time in Korea. The diagnosis and illustrations of this species are provided in addition to a key to the Korean Lispe species.