• Mycobiology
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• 제48권6호
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• pp.495-500
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• 2020

Leaf spot on lemon balm is frequently observed in Korea, causing considerable damage to crops. In 2014 and 2015, the occurrence of leaf spot was observed in several production greenhouses at Suwon, Gongju, and Namwon in Korea. Symptoms on lower leaves initially developed as small, distinct, discolored lesions, which enlarged progressively turning into dark brown, angular spots surrounded by purplish-brown margins. Based on the morphological characteristics and sequence analysis of actin (ACT), translation elongation factor 1-alpha (EF-1α), internal transcribed spacer (ITS), 28S nrDNA (LSU), and RNA polymerase II second largest subunit (RPB2), the fungus associated with the lemon balm leaf spot was determined as Septoria melissae. To the best of our knowledge, this is the first report of lemon balm leaf spot caused by S. melissae in Asia as well as in Korea.

• Applied Microscopy
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• 제45권1호
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• pp.23-31
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• 2015

Dark field (DF) transmission electron microscopy image has become a popular characterization method for two-dimensional material, graphene, since it can visualize grain structure and multilayer islands, and further provide structural information such as crystal orientation relations, defects, etc. unlike other imaging tools. Here we present microstructure of graphene, particularly, using DF imaging. High-angle grain boundary formation wass observed in heat-treated chemical vapor deposition-grown graphene on the Si substrate using patch-quilted DF imaging processing, which is supposed to occur by strain around multilayer islands. Upon the crystal orientation between layers the multilayer islands were categorized into the oriented one and the twisted one, and their local structure were compared. In addition information from each diffraction spot in selected area diffraction pattern was summarized.

• The Plant Pathology Journal
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• 제16권6호
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• pp.328-330
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• 2000

A terget leaf spot of red and white clovers was observed during 1998-2000 growing seasons in several fields of Chungnam and Chungbuk provinces in Korea. Lesions were circular to oval in outline, brown to dark brown, ranging from a pinpoint to 3-4 mm in diameter, often concentrically zonate and presenting a target effect. A fungus associated with the disease was identified as Stemphylium sarciniforme based on the morphological characteristics of the conidiophores and conidia. The fungus was pathogenic on red and white clovers in the inoculation test. This is the first record of a terget leaf spot of red and white clovers in Korea.

• 대한소아치과학회지
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• 제24권1호
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• pp.313-324
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• 1997

The aim of the present study was to describe an safe and convenient method for the early detection of enamel caries using laser fluorescence. Fluorescence from natually carious lesion of human teeth illuminated by an argon laser(488nm) was observed and photographed using barrier filter. Intact enamel was found to fluorescence with a yellowish light. Whereas, incipient caries lesions in the enamel were dearly visible as dark areas in contrast to the fluorescence surroundings. For evaluation of accuracy of this method, lesion depth measured by the laser fluorescence in light microscope was compared with that polarizing microscope. The results from the present study can be summarized as follows : 1. Enamel caries of smooth surface was observed as pale white spot and undefined outline in ordinary light. Whereas, lesion was clearly visible as dark spot in laser fluorescence. 2. There was no difference between ordinary light view and laser fluorescence in occlusal surface and interproximal surface. 3. There was no significant difference between the lesion depth observed by laser fluorescence with light microscope and polarizing microscope. Apparent correlation exists between two groups.

• 한국균학회지
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• 제33권1호
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• pp.35-37
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• 2005

2002년부터 2003년까지 2년 동안 경남 거제시 학동면 조팝나무 재배농가에서 잎과 줄기에 이상증상이 심하게 발생하였다. 병징은 처음 잎에 암적갈색의 작은 둥근 반점이 많이 생기고, 줄기에 검은색 반점이 나타나며 진전됨에 따라 약간 움푹하게 들어가고 긴 타원형으로 검게 썩는다. 심하게 발생하면 병든 가지 윗부분은 말라 죽는다. 균총은 PDA배지에서 회색이고 분생포자 모양은 단세포, 원통형이며 크기는 $6{\sim}12{\times}3{\sim}5\;{\mu}m$였다. 강모의 색깔은 암갈색이고 바늘모양의 원추형이며 크기는 $23{\sim}42{\times}2{\sim}4\;{\mu}m$이었다. 균사생육 최적온도는 $30^{\circ}C$였다. 분리된 병원균으로 병원성을 검정한 결과, 자연 감염된 병징과 똑같았다. 이상의 결과를 가지고 본 병해를 Colletotrichum gloeosporioides에 의한 조팝나무 탄저병으로 명명할 것을 제안한다.

• Animal Systematics, Evolution and Diversity
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• 제27권3호
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• pp.274-276
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• 2011

A nolid species, Roeselia triangulalis (Leech) is reported for the first time from Korea. Two males were collected from Jeju Island, South Korea. Roeselia triangulalis can be distinguished by the bipectinate male antennae, broad frons, long labial palpi, costally dark brownish spot and the rounded dark brownish postmedial line of forewing. In the male genitalia, the long saccus, the slender valve with distally expanded and spine-like harpe and long spinular cornutus of vesica are distinguishing characters. In the female genitalia, the simple sterigma, the long ductus bursae and the large ovate corpus bursae with a lip-shaped signum are distinguishing characters. Diagnosis and description of the species are given with the figures of the male genitalia.

• 식물병연구
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• 제14권1호
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• pp.68-70
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• 2008

2006년 6월 전남 순천과 고흥지역의 농가에서 재배되고 있는 참다래 잎에 갈색 점무늬 증상이 나타나기 시작하여 점차 짙은 갈색의 둥근 무의로 확대되었고, 심할 경우에는 생육기 동안에도 낙엽을 초래하였다. 둥근 무늬병반에서 일관성 있게 분리된 Alternaria sp.를 순수배양시켜 관찰한 균학적 특징과 참다래 잎에 상처접종에 의한 확인된 병원성을 토대로 Alternaria alternata (Fr.) Keissler에 의한 참다래 갈색둥근무늬병으로 동정하였다. A. alternata는 감자한천배지에서 짙은 회색 균총을 형성하였고 분생포자를 다량 형성하였다. 담갈색 또는 금색의 분생포자는 난형 또는 역곤봉 형태를 하며, 분생포자경 위에 보통 5개 이상 사슬모양으로 형성되는데, 횡격막이 $3{\sim}5$개, 종격막이 $1{\sim}2$개가 있고, 분생포자의 크기는 $16.5{\sim}42.1{\times}6.7{\sim}19.5\;{\mu}m$, 분생포자경의 길이는 $8.6{\sim}112.7\;{\mu}m$였다. 이상과 같이 국내 최초로 A. alternata에 의한 참다래 갈색둥근무늬병의 발생을 보고하는 바이다.

• Journal of Plant Biology
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• 제4권1호
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• pp.21-24
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• 1961

The strains of fungus which belong to Coniothyrium genus were isolated from leaf spoot of Yucca. The isolated strain can grow easily and forms characteristic colonies on Saido's soy agar. There are definite differences, according to other authors, (By Miyake et Hara 1911) Pycnidio-spore are usually formed ellipsoidal, dark brown, 4$\times$2. 5-4. $O\mu$ in size, whereas isolated strains are globose, yellowish brown, 2.8-4.2$\mu$ in diameter. The positive inoculation test can be attained by burned petridish method, preserving it in incubator at 28$^{\circ}C$, and the pycnidio-spore can be reisolated from the inoculated portion. (Photo.7) Up to the present day there is no report for leaf spot of Yucca caused by Coniothyrium sp.. Comparing the writer's isolate with those fungi described(leaf spot of alloe, rose canker and elm canker etc.) hitherto, there are no accordance in the symptom and especially in morphological charactgers and Pathogenicitys.

• 제어로봇시스템학회논문지
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• 제15권5호
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• pp.473-479
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• 2009

This paper proposes an efficient method to locate the automated guided vehicle (AGV) into a specific parking position using artificial visual landmark and vision-based algorithm. The landmark has comer features and a HSI color arrangement for robustness against illuminant variation. The landmark is attached to left of a parking spot under a crane. For parking, an AGV detects the landmark with CCD camera fixed to the AGV using Harris comer detector and matching descriptors of the comer features. After detecting the landmark, the AGV tracks the landmark using pyramidal Lucas-Kanade feature tracker and a refinement process. Then, the AGV decreases its speed and aligns its longitudinal position with the center of the landmark. The experiments showed the AGV parked accurately at the parking spot with small standard deviation of error under bright illumination and dark illumination.

• 식물병연구
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• 제28권2호
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• pp.57-60
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• 2022

Leaves of Chionanthus retusus were found to be damaged by leaf spot disease associated with a fungus in Iksan, Korea. Leaf spots were angular to irregular, vein-limited, scattered, 1-8 mm diameter, brownish-gray to dark brown when dry, with heavy fructification. The pathogen causes premature defoliation of C. retusus plant and was identified as Pseudocercospora chionanthi-retusi based on morphological and molecular-phylogenetic analyses. The phylogenetic tree was constructed using multi-locus DNA sequence data of partial actin (actA), partial translation elongation factor 1-alfa (tef1), partial DNA-directed RNA polymerase II second largest subunit (rpb2) genes, and internal transcribed spacer regions. Current study provides detail morphological description of P. chionanthi-retusi on C. retusus in Korea, with supports of phylogenetic analysis and pathogenicity test.