• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.393-394
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• 2020

세 군 매칭을 수행하여 관찰 데이터를 구축하고 통계분석에 기반한 연구를 수행하는 경우가 종종 발생한다. 매칭작업은 각 군에 속한 개체의 성향점수를 서로 비교해 거리가 가까운 짝을 찾아야 하므로 카테시안 곱 만큼의 경우의 수를 따져야 하는 문제이고, 메모리 소요가 크다. 특히 세 군 매칭은 세 쌍의 거리가 가까운 triplet을 찾는 문제로, 세 개체 사이에 존재하는 세 개의 거리를 따져야 하기 때문에 메모리 소요가 두 군 매칭에 비해 훨씬 크다. 각 군에 속한 개체가 늘어나면 메모리소요가 기하 급수적으로 늘어나게 된다. R패키지에 포함된 TriMatch함수는 세 군 매칭 수행을 위해 가장 널리 사용되는 프로그램이다. 이 프로그램은 세 개체 사이의 세 개 거리가 가장 짧은 triplet을 찾는 방식으로 구현 되었다. 이 프로그램은 메모리 소요가 매우 커 각 군에 속한 개체의 수가 많아지면 메모리 부족 에러가 발생하는 경우가 많다. 본 연구에서는 세 군 매칭에 소요되는 메모리 소요를 줄일 수 있는 알고리즘을 제안하고자 한다. 이 알고리즘의 구현을 통해 각 군에 속한 개체가 늘어나도 안정적인 세 군 매칭 결과를 얻을 수 있을 것으로 기대한다.

• Korean Journal of Environment and Ecology
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• v.35 no.5
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• pp.548-557
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• 2021

Cypripedium japonicum Thunb. is an endemic plant in East Asia, distributed only in Korea, China, and Japan. At the global level, the IUCN Red List evaluates it as "Endangered Species (EN)," and at the national level in Korea, it is evaluated as "Critically Endangered Species (CR)." In this study, we investigated the characteristics of the age structure and the sustainability of the population based on the data obtained by demographic monitoring conducted for seven years in the natural habitat. C. japonicum habitats were observed in 7 regions of Korea (Pochoen, Gapyeong, Hwacheon, Chuncheon, Yeongdong, Muju, Gwangyang), and 4,356 individuals in 15 subpopulations were identified. The population size and structure differed from region to region, and artificial management had a very important effect on the size and structural change of the population. Population viability analysis (PVA) based on changes in the number of individuals of C. japonicum showed a very diverse tendency by region. And the probability of population extinction in the next 100 years was 0.00% for Pocheon, 10.90% for Gwangyang, 24.05% for Chuncheon, and 79.50% for Hwacheon. Since the above monitored study sites were located within the conservation shelters, which restricted access by humans, unauthorized collection of C. japonicum, the biggest threat to the species, was not reflected in the individual viability. So, the risk of extinction in Korea is expected to be significantly higher than that estimated in this study. Therefore, it is necessary to reflect population information in several regions that may represent various threats to determine the extinction risk of the C. japonicum population objectively. In the future, we should expand the demographic monitoring of the C. japonicum population known in Korea.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.658-675
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• 2016

The environmental characteristics of the habitats, the population structures, ecological niche, life traits and the population demography are used as an essential informations to the effective conservation plans about the target species. We first confirmed a total of 37 populations through 12 years of investigation on the extents, and investigated the environmental factors of habitats and the population structures of the 25 cohorts in 12 regions among them. And, we investigated the population dynamics targeting at 8 cohorts in the population of Daegwanryeong-myeon, Pyeongchang-gun, Gangwon-do. Along with this, we conducted 4 years of cultivation experiments and how pollinators affect the success of reproduction. The results shows that the Paeonia obovata Maxim. was found in a relatively wide range of habitats. For the population structures of the 25 cohorts, there were considerable differences among cohorts, including a case which showed relative stable structure and an extreme case in which only adults were found. The factor that affected the population dynamics during the investigation was thought as a forest gap created in the tree layer. In the cultivation experiment, seedlings grew well in a less soil organic matter. The seed setting rate and the number of seeds generated by visiting pollinators were higher trends. In conclusion, to understand the distribution of the Paeonia obovata Maxim., there needs to be investigated on the other factors that are involved in dispersal factors other than environmental factors, and thus we suggest the necessity of the research on the dispersal vectors. The current Paeonia obovata Maxim. population was thought as a process of expansion after the rapid reduction of the extents in the past. For the effective conservation of the Paeonia obovata Maxim., an endangered plant, we recommend to understand the species through the spatio-temporal expansion, and maintain the health of the ecosystem based on it.

• Korean Journal of Ichthyology
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• v.23 no.2
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• pp.95-105
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• 2011

To explain the origin of the Korean mandarin fish (Siniperca scherzeri), phylogenetic relationships and DNA polymorphism among Siniperca fishes have been investigated based on mitochondrial cytochrome b DNA sequences. As a result, S. roulei were firstly differentiated early in the evolution of Siniperca fishes and the other six species (S. schezeri, S. undulata, S. fortis, S. obscura, S. knerii and S. chuatsi) were evolved slightly later. However, the order of species differentiation among six species was not clear because the nodes of their phylogeny were poorly resolved. The constructed molecular phylogeny revealed three genetically distinct groups of local populations of S. scherzeri. The first group (group 1) is the local populations of Korean peninsula and northern China including Lioaning and Henan. The second one (group 2) is the local populations of Anhui, Fujian and Guangxi. The third one (group 3) is the local population of Zhejiang. The number of nucleotide differences in base pairs were 31~43 between group 1 and 2; 37~44 between group 2 and 3; 27~29 between group 1 and 3; and 1~5 within group 1. Thus, the Korean mandarin fish was likely to be originated from the northern China local population which was isolated from the middle or southern China local populations during the Cenozoic Pliocene. Low level of sequence divergence between Korean mandarin fish populations and northern China population indicated a recent expansion of distribution ranges from northern China to Korean peninsula.

• Journal of Aquaculture
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• v.22 no.1
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• pp.92-99
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• 2009

Population dynamics and sexual maturity of Neomysis japonica (Ishikawa and Oshima, 1951) were investigated from a shrimp farm in Tae-an, Korea. N. japonica was collected monthly at the shrimp farm belonging to the Marine and Fisheries Research Institute, the Soonchunhyang University from October 2002 to September 2003. The proportion of female was higher than that of male. The mean carapace length of male (2.42 mm) was larger than that of female (2.31 mm). Brood size increased with increasing female body size. The size of N. japonica at 50% sexual maturity was approximately 4.4 mm. N. japonica females grew faster and reached larger size than males. The mortality rate (z) calculated by length-converted catch curves was $3.46\;yr^{-1}$. The annual recruitment pattern of N. japonica had two major peaks. Log-transformed total length was significantly related with log-transformed carapace length.

• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.209-218
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• 2006

This study was to evaluate microcystin production by two strains of cyanobacteria (Microcystis aeruginosa and Planktothrix agardhii) in response to three different levels of direct (0,4,8 inds.) or indirect (0,25, 50% of zooplankton culture media filtrate) exposures to zooplankton (Daphnia magna and Moina macrocopa). The cell biomass and intracellular microcystin (MC) were measured everyday. The survival rates of zooplankton were evaluated for daily intervals for the direct exposure. The intracellular MC produced peaked on the day 3 or 4, and then decreased over the both exposure experiment. In the direct experiment, the MC values were significantly different among the control and zooplankton treatments (ZT; repeated measures-ANOVA: P< 0.039). The MC contents of P. agardhii strain (No.204) were significantly higher (Tukey test, P< 0.082) in ZT2 (8 inds.) than in ZT2 (4 inds.). On the peak day, the intracellular MC exposed to both zooplanktons was significantly higher than the control (One-way ANOVA, P< 0.021). Higher zooplankton survivals were observed in the M. aeruginosa strain (No. 111) rather than in high toxic P. agardhii strain. In the indirect experiment, the intracellular MC of the M. aeruginosa strain was significantly different among the control and zooplankton culture media filtrate (ZCMF)treatments (rm-ANOVA: P<0.004), The MC exposed ZCMF2 (50%) were significantly higher than in ZCMFI (25%: Tukey test, P< 0.025) for both strains. This study strongly supports the induced-defensive MC production of potentially toxic cyanobacteria in response to the presence of zooplankton.

• Korean journal of applied entomology
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• v.48 no.3
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• pp.301-310
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• 2009

For the comparing of mortality of the resistance and susceptible population of Myzus persicae, etofenprox was treated in the recommended concentration of 200ppm. Mortalities of resistance population were 16.7 and 36.7%, and susceptible population were 86.7 and 86.7% after 24 and 48 hours treatment, respectively. For the detect of cross resistance to other pyrethroids, 6 pyrethroids were examined. Mortalities of susceptible and resistance populations were 90 and 31% to deltamethrin, 92 and 23% to lambda cyhalothrin, 81 and 14% to cypermethrin, 70 and 20% to $\alpha$-cypermethrin, 29 and 28% to fenpropathrin, 84 and 29% to fenvalerate, respectively. It was showed that resistance populations were generally resistive to other pyrethroids. On the other hands, for recognized ecological characteristic of M. persicae susceptible and resistance populations life table was tested on the pepper leaves in the petri dish and on the plant in the pot. This results were showed that intrinsic rate of increase ($r_m$), net reproduction number ($R_0$) and generation time in day ($T_c$) were significantly different between two population in both tested. However, life span and reproduction period were slightly different between them. Otherwise, feeding behaviors were tested using EPG technique with non- and treated etofenprox. First potential drop time of susceptible and resistance population was 73.5 and 257.9 sec with non-treated and 93.3 and 1076.2 sec after treated, respectively. Electrical probing signals were 8.2 and 48.8 times with susceptible and resistance individuals after treated etofenprox, respectively. It was supposed that the resistance is more probings than susceptible population. After treated, total feeding time have more 6,728.9 sec on resistance than 965.5 sec on susceptible population. So, total non penetration time of susceptible population was 3,000 sec longer than resistance population.

• Journal of Korean Society of Forest Science
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• v.103 no.1
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• pp.147-151
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• 2014

This study was conducted to clarify the characteristics of amphibian and reptile (herpetofauna) populations in a coniferous plantation and a deciduous forest from July to September 2013 in national forest, Hongcheon, Gangwon province, Korea. Coverage of understory, mid-story and overstory were more developed in a deciduous forest. We used line transect sampling method on a total of 4 transect lines, 2 lines in each forest type. Fifty two individuals of 4 amphibian species and 11 individuals of 3 reptile species were recorded. Mean observed number of herpetofauna species, individuals and species diversity index (H') were not significantly different between coniferous plantation and deciduous forest. This result related to ecological characteristics of herpetofauna. Habitats of herpetofauna were influenced on not only vertical structure of forests, but also climatic variables, thermoregulation and prey availability. The long-term monitoring and research on habitat preference and seasonal ecological traits of herpetofauna would be needed for conservation and management of herpetofauna in forest areas.

• Korean Journal of Organic Agriculture
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• v.21 no.4
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• pp.601-615
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• 2013

This study was conducted to compare the community structure and biodiversity of arthropods between conventional and organic red pepper fields. A total of 36 species of 24 families belonging to 10 orders from collected 28,718 arthropods; 6,901 individuals from conventional field and 21,871 individuals from organic field. A number of species comprising arthropod community was same in both fields as 32 species. Species richness of Diptera was the highest in conventional field and that of Hymenoptera and Colembolla was the highest in organic field. Abundance of Frankliniella intonsa was the highest regardless of farming method. Helicoverpa assulta was dominant in conventional field, and Homidia mediaseta, Diptera sp. 4 and Pardosa astrigera were dominant in organic field. Diversity of community on the ground was higher in organic field and statistically different. Similarity of arthropod community showed difference with 34.07% on the ground and 26.95% in the plant above ground. In the ecologically functional guild: species richness of general, pest and parasitoid of natural enemy groups in the plant above ground were statistically different and pest and parasitoid groups were higher in organic field, abundance of predator group of natural enemy on the ground was 2 times higher in organic field and statistically different and diversity of general and parasitoid groups in the plant above ground were statistically different. In the relative occupancy rate, pest group was the highest in conventional field and decomposer group was the highest in organic field. The results of present study is considered to provide useful information of arthropod community for developing efficient insect pest management in organic farming.

• Korean Journal of Environmental Agriculture
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• v.32 no.1
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• pp.24-34
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• 2013

BACKGROUND: This study was carried out to compare population size of mudfish (Misgurnus mizolepis) between the agricultural practices and to investigate the causes of its differences. We also provided basic information for sustainable use of mudfish population in paddy fields. METHODS AND RESULTS: Mudfish and benthic invertebrates which are diet of mudifish were investigated from 8 sites of organic and conventional rice paddy fields in South Korea. Total number of mudfish were 1,882 individuals in survey sites. Mudfish population were 2.4 times larger in organic paddy fields (1,333 individuals) than in conventional paddy fields (549 individuals). The population size of mudfish was larger in Mungyeong-si, Gyeongsangbuk-do and Anseong-si, Gyeonggi-do with relatively better environmental conditions than the other 5 sites including Suwon-si, Gyeonggi-do, Cheongyang-gun, Chungcheongnam-do, Gunsan-si, Jeollabuk-do, Gimje-si, Jeollabuk-do, Hwasun-gun, Jeollanam-do, Hamyang-gun, Gyeongsangnam-do. Benthic invertebrates collected from survey sites were 74 species, 68 genera, 46 families, 19 orders, 6 classes and 3 phyla. According to agricultural practices, benthic invertebrates were identified 66 species, 62 genera, 41 families, 17 orders, 6 classes and 3 phyla in organic paddy fields while there were 66 species, 60 genera, 42 families, 18 orders, 6 classes and 3 phyla in conventional paddy fields. Dominant invertebrates were Chironomidae sp., Branchiopoda sp., Ostracoda sp., and Copepoda sp. There were no differences in dominant species between organic and conventional paddy fields. Population size of mudfish tended to increase with the population size of Chironomidae sp., Branchiopoda sp., Ostracoda sp., and Copepoda sp. But, only population of Chironomidae sp. and Copepoda sp. statistically related to population size of mudfish. The number of individuals of mudfish (Misgurnus mizolepis) was higher at the low rate of urban area than any other surveyed region and was affected by appearance ratio of main preys such as Chironomidae sp. and Ostracoda sp. CONCLUSION(S): The population size of mudfish in rice paddy fields could be affected by environmental conditions and agricultural practices such as organic and conventional methods.