• Title/Summary/Keyword: fern

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Unrecorded fern species from Korean flora: Nephrolepis cordifolia (Nephrolepidaceae), Athyrium epirachis (Athyriaceae) and Asplenium castaneo-viride (Aspleniaceae) (한국산 미기록 양치식물: 줄고사리 (줄고사리과), 산중개고사리 (개고사리과), 거미꼬리고사리 (꼬리고사리과))

  • Kim, Chul Hwan;Moon, Myung Ok;Kang, Young-Je;Kim, Chan Soo;Ahn, Jin Kap;Sun, Byung-Yun
    • Korean Journal of Plant Taxonomy
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    • v.35 no.4
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    • pp.287-294
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    • 2005
  • Three unrecorded fern species from the flora of Korea, Nephrolepis cordifolia, Athyrium epirhachis, and Asplenium castaneo-viride, are reported here. Nephrolepis cordifolia, recognized as introduced species and cultivation in Korea until now, is found in the wild at the entrance of small cave in Jeju island. Athyrium epirhachis is found under the Quercus acuta forest at about 400 - 500 m alt. in Jeju island. This species is similar to A. otophorum but different from the latter by having once pinnately divided leaf blade and the decurrent base of ultimate segment. Asplenium castaneo-viride is hybrid between A. ruprechtii and A. incisum and is distinguished from parental species by presence of proliferation, shape of leaf blade, pattern of venation, and leaf texture.

Projecting suitable habitats considering locational characteristics of major wild vegetables and climate change impacts

  • Choi, Jaeyong;Lee, Sanghyuk
    • Korean Journal of Agricultural Science
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    • v.46 no.3
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    • pp.661-670
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    • 2019
  • In this study, we constructed a model of an area where the production and production amount of wild vegetables which are designated as short term income forest products for the whole country are self-sufficient for the representative Eastern Braken fern(Pteridium aquilinum)and Edible aster(Aster scaber). The difference between the existing cultivation site and the model result was examined, and the distribution of the cultivable area was simulated according to the near future climate change by the 2050s. The degree of agreement between the cultivated area and the actual native area was very low at 14.5% for Eastern Braken fern and 12.9% for Edible aster. Using the Maxent model, which has already been proven by many research examples, the cultivation maps through the model can guarantee statistical accuracy by considering many variables. To analyze future location changes, the RCP 4.5 scenario and the RCP 8.5 scenario were applie Edible aster d to predict potential future cultivable areas and compare them to the present. There was no decrease in the cultivable area due to climate change nationwide. However, in the RCP 8.5 scenario for Eastern Braken fern and the RCP 4.5 scenario for Edible aster, declining areas such as Gangwon-do, Jeollabuk-do and Gyeongsangbuk-do showed prominence according to the scenarios. The result of this study suggests that various models can be used for the production of short-term forest productivity maps and it will be used as a climate change impact assessment data for competitive forest products considering the influence of future climate change.

CORRECTION OF SWITCHING DEAD TIMES IN PWM INVERTER DRIVES

  • Lee, Kun-Yong
    • Proceedings of the KIEE Conference
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    • 1990.11a
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    • pp.287-290
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    • 1990
  • The paper describes the correction of the switching dead times avoiding a bridge leg short circuit in pulse width modulated voltage sorce inverters. The co consequences on AC variable speed drives with synchronous and asynchronous motors are described by harmonic analysis and by computer simulation.

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Multiple Symbiotic Associations Found in the Roots of Botrychium ternatum

  • Lee, Jun-Ki;Eom, Ahn-Heum;Lee, Sang-Sun
    • Mycobiology
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    • v.30 no.3
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    • pp.146-153
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    • 2002
  • Two types of mycorrhizae, orchid(OM) and arbuscular mycorrhizae(AM), were observed in the cortical cells of Botrychium ternatum roots. The vesicles or arbuscules of AM fungi were examined and the fresh or digestive pelotons by other species of basidiomycetes were also observed in the roots under light microscope. These symbioses were, as the genomic DNAs extracted from roots of B. ternatum reacted with the specific primers, confirmed with PCR technique, being added to more strong evidences. These discoveries were rarely happened in the roots, especially a fern in nature. OM was observed in the roots of B. ternatum collected from the nationwide areas, whereas AM was only in the roots of B. ternatum collected from Chung-Buk areas. It is speculated that OM are associated with the nitrogen cycle in Islands and the growth of B. ternatum in the inland of Central Korea is related to both the phosphate and nitrogen cycle in the nature. The results suggest that B. ternatum is a typical species with two types of mycorrhizae under various growing conditions.

Effect of Nitrogen Application Rate on Growth of Rumohra aristata and Cyclosorus dentatus of Korea Native Fern (질소시비량이 자생 가는쇠고사리와 탐라별고사리의 생육에 미치는 효과)

  • Hwang, Byoung-Tae;Ju, Jin-Hee;Bang, Kwang-Ja
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.8 no.3
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    • pp.67-72
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    • 2005
  • For the two species of native fern that have high development potential for interior landscape, Rumohra aristata and Cyclosorus dentatus, the physiological and growth characteries as nitrogen application rate such as $NaNO_3$ 0.0mg/L, $NaNO_3$ 0.5mg/L, $NaNO_3$5.0mg/L, $NaNO_3$ 50mg/L and $NaNO_3$ 500mg/L were surveyed. 1. A significant changes of Rumohra aristata, in top growth was not distinctive. However, as nitrogen application rate increased, the numbers of leaves declined and the content of chlorophyll and the number of wilted leaves increased. 2. As nitrogen application rate increased, the top growth of Cyclosorus dentatus and the content of chlorophyll was increased. However, its overall, ornamental value was reduced due to the rising number of wilted leaves and the declining number of new leaves.

Efficient Parallel TLD on CPU-GPU Platform for Real-Time Tracking

  • Chen, Zhaoyun;Huang, Dafei;Luo, Lei;Wen, Mei;Zhang, Chunyuan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.1
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    • pp.201-220
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    • 2020
  • Trackers, especially long-term (LT) trackers, now have a more complex structure and more intensive computation for nowadays' endless pursuit of high accuracy and robustness. However, computing efficiency of LT trackers cannot meet the real-time requirement in various real application scenarios. Considering heterogeneous CPU-GPU platforms have been more popular than ever, it is a challenge to exploit the computing capacity of heterogeneous platform to improve the efficiency of LT trackers for real-time requirement. This paper focuses on TLD, which is the first LT tracking framework, and proposes an efficient parallel implementation based on OpenCL. In this paper, we firstly make an analysis of the TLD tracker and then optimize the computing intensive kernels, including Fern Feature Extraction, Fern Classification, NCC Calculation, Overlaps Calculation, Positive and Negative Samples Extraction. Experimental results demonstrate that our efficient parallel TLD tracker outperforms the original TLD, achieving the 3.92 speedup on CPU and GPU. Moreover, the parallel TLD tracker can run 52.9 frames per second and meet the real-time requirement.

Rotation Invariant Face Detection with Boosted Random Ferns (Boosted Random Ferns를 이용한 회전 불변 얼굴 검출)

  • Kim, Hoo Hyun;Cho, Dong-Chan;Bae, Jong Yeop;Kim, Whoi-Yul
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2013.06a
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    • pp.52-55
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    • 2013
  • 본 논문은 Boosted Random Ferns 기반의 회전 불변 얼굴 검출 방법을 제안한다. 기존 Random Ferns 의 경우 특징값을 추출할 때 임의로 선택한 두 픽셀의 밝기값 비교를 통하여 이진 특징값을 추출한다. 이 경우 해당 픽셀의 밝기값에 잡음이 포함되면 특징값이 부정확하게 추출되는 문제가 있다. 본 논문에서는 이러한 문제를 해결하기 위하여 임의로 두 블록을 선택하고 해당 블록내 밝기값의 평균을 비교하여 이진 특징값을 추출하였다. 또한 픽셀 위치를 임의로 선택하여 ferns 를 구성하였던 기존의 방법 대신 최고의 분류 성능을 가지는 fern 들을 이용하여 분류기를 구성하기 위해, AdaBoost 의 방법을 Random Ferns 에 맞게 변경하였다. Boosted Random Ferns 를 트리 구조의 cascade 노드에 방향과 각도에 따라 배치하여 연산 속도를 향상시키고 false-positive를 줄이는 효과를 보았다. CMU Rotated Face Database 를 사용하여 평가하였을 때, 기존 Random Ferns 는 false-positive 의 수가 57 개 일 때 66%의 검출률을 보인 반면, Boosted Random Ferns 는 false-positive 의 수가 45 개 일 때 88%의 검출률을 보였다.

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