• Korean Journal of Plant Resources
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• v.25 no.4
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• pp.433-446
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• 2012

The preliminary study for providing the relationship of the factors which are climate and the pteridophyta was carried out. Dormancy form and leaf phenology of the 321 taxa belonging to 27 families were analyzed. This survey shows life-form spectrum of Korean ferns. The results obtained from this study were as follows: Deciduous (d), Evergreen (e) and Summer-deciduous (sd) were calculated as 37.4%, 59.2%, 1.9%, respectively and the Evergreen (e) has the highest value compared to the other leaf phenologies. It observed from the life-form spectra that Hemicryptophytes (H) was the most common dormancy form at 42.1%. Geophytes (G), Epiphytes (E) and Chamaephytes (Ch) were calculated at 25.5%, 15.9%, and 11.8%, respectively. There will be a discussion about geographical distribution of Korean ferns and possibility of their distribution range.

• Korean Journal of Plant Taxonomy
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• v.35 no.3
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• pp.187-192
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• 2005

During a recent trip to Hainan Island of China, we collected some filmy ferns from Diaoluo Mountain in the southeastern of the island. Trichomanes subclathratum turns out to be a new record to the Hainan fern flora, and also represent new record to China, and Mecodium riukiuense, so far has been unaware to Chinese pteridologists is also recorded here.

• Journal of the Korean earth science society
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• v.37 no.5
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• pp.295-308
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• 2016

Nine species of fossil plants were described based on the new material collected from the Hasandong Formation. They are as follows: Thallites yabei, Onychiopsis elongata, Cladophlebis denticulata, C. shinshuensis, C. (Eboracia ?) lobifolia, C. (Klukia ?) koraiensis, Brachyphyllum japonicum, Elatocladus tennerima, and Taeniopteris ? sp. cf. T. auriculata. The floristic composition of the Hasandong flora is very similar to that of the Nakdong flora. This means that both floras might have flourished under subtropical warm arid climate. This flora contains both the Tetori-type and Ryoseki-type floras. It is considered that the Hasandong flora is a member of the Mixed-type floras that existed in eastern Eurasia during the Late Jurassic to Early Cretaceous time.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.230-231
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• 2017

극동지역에서 Loran-C 국제협력 체인의 구성에 따란 한국, 중국, 러시아 3개국에 상호호혜원칙에 따라 이용범위의 증대 및 전파표지의 연구 발전을 도모하는 등 전파표지분야의 협력과 발전을 위하여 협정서에 명시된 정책수행과 협정 체약국간 활동을 조정하는 역할을 하며 초기('92.9.7)에는 기관간의 협정으로 시작하였으나 '00.12.22에 정부간 협정으로 변경되어 그동안 Loran-C 국제 협력체인을 구성하는 한편 전파표지에 관한 정보 교환 및 운영절차 마련 등으로 해상교통안전에 크게 기여하고 있다. 최근 해사안전정보(MSI) 제공과 GNSS 전파간섭에 대비한 위치정보 제공에 관한 관심이 대두되면서 향후 FENRS에서 협력하고 발전해나갈 방향을 제시하고자 한다.

• Research in Mathematical Education
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• v.5 no.1
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• pp.1-12
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• 2001

Generating fractal images by graphing calculators such as TI_92 combines several important features, which convey the excitement of a living, changing mathematics appropriate to secondary or post-secondary students. The topic of fractal geometry can be illustrated using natural objects such as snowflakes, leaves and ferns. These complex and natural forms are often striking fantastic and beautiful. The examples highlight the fact that complex, natural behaviors can result from simple mathematical rules such as those embodied in iterated function systems(IFS). The visual splendor beauty of fractals, in concert with their ubiquity in nature, revels the intellectual beauty of nonlinear mathematics in a compelling way. The window is now open for students to experience and explore some of the wonder of fractal geometry.

• Journal of the Korean Wood Science and Technology
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• v.29 no.3
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• pp.83-91
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• 2001

This paper examines the structural characteristics of fern lignins (deer fern (Blechnum spicant), sword fern (Polystichum munitum) and maidenhair fern (Adiantum pedatum)) by chemical degradation methods of thioacidolysis and nitrobenzene oxidation as well as 13C NMR. Phloroglucinol-HCI staining indicates that the lignins are specifically accumulated at the sclerenchyma cells beneath the epidermis and vascular bundles. The fern lignins consist of only guaiacyl units. Remarkably, the frequency of the -O-4 linkages is extremely low in fern lignins (only 9 to 11 %). Furthermore, the presence of lignin is ambiguous in maidenhair fern, due to very rare amount of -O-4 linkage. Biphenyl (5-5) and 1,2 bis arylpropane (-1) are main condensed dimeric substructures in fern lignins over 70%. In addition, 13C NMR analysis strongly evidenced the integration of phenolics or their derivatives into the fern lignins.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.328-330
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• 1994

The Ultrasonic motor(USM) has many good characteristics such as high torque at low speed range, large holding torque based upon frictional force, high speed response, flexible free ferns, compactness in size, low magnetic noise and silentness in motion. Because of having low speed rotation, USM is good as an actuator of a small size direct drive (DD) manipulator. The acturators for the DD manipulators must have good controllability on the speed and torque from zero to maximum value continuously. New method was developed for speed and torque control by the phase difference control of the two-phase driving signals of the motor. Then rule adjustable compliant and dumped motion was realized on the output shaft of the motor by PD control of the output shaft angle.

• The Korean Journal of Ecology
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• v.11 no.3
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• pp.137-144
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• 1988

The use of modern pollen spectra for comparative interpretation of fossil pollen sequence requires the ability to distinguish different vegetation types by their pollen spectra, which may show similarities to fossil assemblages. Tertiary marine and non-marine sediments, the Yeonil Group, of the Yeonil area, Korea, was found thirty-two palynomorphic genera. One of the characteristic features of Yeonil geo-flora is predominance of coniferous trees over shrubs, herbs, and ferns. Miocene deposits of Yeonl area, Korea, ae differentiated with five zones. According to the pollen diagram it can be inferred the climate of the Tertiary Miocene of the Yeonil area, Korea.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.984-987
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• 2014

본 논문에서는 단일 카메라를 이용하여 차량의 위치를 검출하고 연속적으로 입력되는 영상에서의 차량의 움직임을 추적하는 알고리즘을 제안한다. 차량의 특징을 검출하기 위해 대표적으로 사용하는 SIFT와 SURF 알고리즘보다 성능이 좋은 Ferns 알고리즘을 사용하고 Optical Flow Tracker를 이용하여 차량의 위치를 추적한다. 신뢰도를 높이기 위해서 이전 프레임에서 학습되지 않은 특징에 대해 지속적으로 학습하여 새로운 학습결과를 도출하여 업데이트한다. 기존의 차량 검출 알고리즘보다 본 논문에서 제안하는 알고리즘이 Ferns에 의한 학습과 Optical Flow Tracking의 상호작용으로 높은 매칭률과 효율성을 보였다.

• Mycobiology
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• v.47 no.1
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• pp.120-125
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• 2019

In 2017, small, elliptical, brownish purple spots on spears and ferns of asparagus were found in fields of Gangwon-do. The isolated fungal species was identified as an ascomycete Stemphylium vesicarium based on morphological characteristics and molecular phylogenic analyses including nucleotide sequences of the internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and cytochrome b (cytb). A pathogenicity test revealed that S. vesicarium was the causal agent of purple spot disease on asparagus. The occurrence of purple spots caused by S. vesicarium on asparagus is the first report in Korea.