• Korean journal of applied entomology
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• 제54권1호
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• pp.17-23
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• 2015

A complete control on quarantine insect pests is required for exporting domestic apples to other countries. To this end, a controlled atmosphere and heat treatment system (CATTS) has been developed as a post-harvest treatment. This study determined the CATTS conditions to control completely two lepidopteran insect pests, the smaller tea tortrix moth, Adoxophyes paraorana and the peach pyralid moth, Dichocrocis punctiferalis, which exhibit different feeding behviors. In both species, the fifth instar larvae were the most tolerant developmental stage to the heat treatment. Under CATTS conditions with 15% $CO_2$ and 1% $O_2$ for 1 h heat treatment at $46^{\circ}C$, the fifth instar larvae of A. paraorana exhibited a complete lethality, while those of D. punctiferalis underwent 88% mortality. To control completely the fifth instar larvae of D. punctiferalis, 2 h heat treatment required under the same atmosphere condition. These CATTS treatment effects were confirmed against over 3,000 fifth instar larvae of each species infesting apples. This study demonstrates that the longer exposure to CATTS conditions is required for the complete disinfestation of the internal apple feeder compared to the non-internal apple feeder.

• Research in Plant Disease
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• 제16권1호
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• pp.86-89
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• 2010

Brown leaf spot caused by Phyllosticta cruenta from 2007 to 2009 occurred severely in an herbs exhibition on Doonggulle (Polygonatum odoratum) at Gangju pond in Jeongchon-myon, Jinju city, Gyeongnam province, Korea. The typical symptoms of this disease were appeared on the brown leaf spot of leaves. Lesions on the leaves were appeared elliptical or irregular with 2~8 mm in size. Infected leaves were wilted, blighted and eventually died. Pycnidiospores and pycnidia of the fungus were abundantly formed on PDA. The optimum temperature for mycelial growth was $20{\sim}{25^{\circ}C}$. Pycnidiospores were not readily formed on PDA, colorless in color, globose~subglobose in shape, $10{\sim}18{\times}5{\sim}12{\mu}m$ in size and appendage hanged $4{\sim}15{\mu}m$ in size. Pycnidia were globose~subglobose in shape, dark brown in color and $60{\sim}162{\times}70{\sim}174{\mu}m$ in size. On the basis of mycological characteristics and pathogenicity test on host plants, the fungus was identified as Phyllosticta cruenta (Kunze: Fries) Kickx. This is the first report on the brown leaf spot of Doonggulle caused by P. cruenta in Korea.

• Research in Plant Disease
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• 제12권1호
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• pp.15-19
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• 2006

This study was carried out to know pathogenicity of the pathogen isolated in several location of Korea and penetration mechanism of the Pseudocercospora vitis ($(L\acute{e}v)$.) Speg. Inoculation tests at room temperature were performed on both sides of leaves with different isolates of the fungus. The typical symptoms appeared on the abaxial leaf surface, but no symptom was observed on the adaxial leaf surface with all isolates. The average incubation period was nine days, since all symptoms appeared from 8 to 10 days after inoculation. In order to know the mechanism of invasion of P. vitis to grapevine, the behavior of penetration hyphae through stomata were compared in two cultivars having different level of resistance. In order to know the mechanism of resistance of grape vine to P.vitis, two cultivars having different level of resistance were compared by counting the numbers and measuring size of the stomata per leaf. In a susceptible cultivar Campbell Early, the number of stomata was more than that of a resistance cultivar 'Kyoho'. In a susceptible cultivar 'Campbell Early', the fungus entered readily into stomata after inoculation. However, in a resistant cultivar 'Kyoho', the fungus seemed to pass over or surrounded only the guard cells. In comparison of height of guard cells of stomata between the two cultivars, significant differences were observed by scanning electron microscopy and light microscopy. The height of guard cells of 'Campbell Early' showed a little higher than those of 'Kyoho' known to be resistant to the fungus.

• Journal of Digital Convergence
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• 제10권10호
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• pp.431-437
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• 2012

In today's modern society, since the Industrial Revolution took place, still lots of goods have been produced in quantity. However, human's instinct has been growing bigger and bigger that he or she wants to possess the works or products of scarcity and aesthetic value of a sculpture handmade by craftsmen, not mass-produced with the same design patterns. Accordingly, it is required that an artist be concerned about the value of figuring out and pursuing an individual's lifestyle, his/her needs and inherent desires. Moreover, by means of visualization technique, an artist should provide the public with several scenarios about the future, letting them choose the one they want democratically. Therefore, with the help of Mokumegane technique, one of the traditional metal crafts techniques, which shows certain organic patterns joining different metals, this research aims for the inheritance of traditional techniques and the objective preparation for high-quality crafts market, studying the patterns expressed on the surface of metals, which are hard to find through machines.

• Journal of the Korean Wood Science and Technology
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• 제40권6호
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• pp.397-405
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• 2012

Installation of deck has been on the rise in Korea recently, but there is little of research on the safety of deck. One of the major factors affecting maneuverability of a pedestrian is frictional force between an outsole of shoe and a surface of the deck. The frictional force is influenced by many factors such as raw material variance of deck, surface convex shape of deck, outsole patterns of shoes, and moist condition of contact surface between deck and shoes. This study focused on evaluating the effect of these factors on the frictional force. Two kinds of deck, which were made of natural wood and wood plastic composite, were used in this study. The surface convex patterns of deck were classified to single nonslip (longitudinal groove processing) and double nonslip (longitudinal and transverse groove processing). Two kinds of shoe outsole patterns, W-shape and rectangle-shape, were used in the tests. Also, the friction tests were carried out at dried surface conditions and water-adsorbed surface condition.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.418-421
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• 2005

The objective of this research work is to investigate the effects of process parameters, such as power of laser, travel speed of laser and material thickness, on kerfwidth and characteristics of the cut surface for the case of cutting of CSP 1N sheet using high power continuous wave Nd:YAG laser. In order to find relationship between the process parameters on the quality of the cut section, such as kerfwidth, surface roughness and the striation formation, several laser cutting experiments are carried out. From the results of experiments, an optimal cutting speed for each cutting condition has been obtained to improve the quality of the cut surface.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.286-291
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• 2004

The objective of this research work is to investigate the influence of process parameters, such as power of laser, travel speed of laser and material thickness, on roughness and striation of the cut surface for the case of cutting of CSP 1N sheet using high power Nd:YAG laser with continuous wave(CW). In order to find the practical cutting region and the relationship between process parameters on the roughness and the striation, several laser cutting experiments are carried out. From the results of experiments, the allowable cutting region and an optimal cutting speed for each cutting condition have been obtained to improve the quality of the cut surface. In addition, it has been shown that the surface roughness is related to the number of striation and depth of valley of the cut surface.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 한국표면공학회 2018년도 춘계학술대회 논문집
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• pp.49.1-49.1
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• 2018

신축성 디바이스는 다양한 디자인을 적용할 수 있고 형태에 대한 제약을 최소화 할 수 있어 수요가 점점 증가하고 있다. 신축성 디바이스의 핵심인 신축 전극에 대한 연구가 활발히 진행되고 있으며, 물결무늬나 코일 형태의 금속 전극, 탄소 소재를 사용한 전극, 하이드로젤 전극 등이 연구되었다. 하지만 이러한 방법들은 공정과정이 복잡하거나, 변형시 전기적 저항 변화가 크다. 또한 단일 소재를 활용한 신축성 전극은 물질적인 한계로 인하여 신축성을 향상시키는 데 한계가 있다. 신축 전극에 많이 사용되는 은 나노와이어는 용액에 분산되어 있어 공정이 쉽고, 좋은 전기적 특성을 가지는 소재이다. 은 나노와이어는 네트워크 형태로 얽혀있어 신축성 있는 배선의 재료로써 좋은 역할을 할 것으로 기대하지만, 은 나노 와이어만 사용하여 제작한 배선은 늘렸을 때 나노와이어들 간의 접촉 불량으로 저항이 증가한다. 이를 보완하기 위해 본 연구에서는 배선을 형성하고 있는 금속 나노소재 간 전기적 접촉을 향상시키기 위해 은 나노와이어와 은 나노입자를 섞어 하이브리드 잉크를 제작하여 전극을 형성했다. 하이브리드 잉크로 제작한 전극을 신축성 있는 고분자에 함입하여 신축률에 따른 저항을 평가했다. $175^{\circ}C$에서 열처리한 전극을 5% 늘렸을 때, 단일 소재인 은 나노와이어나 은 나노입자만을 사용한 경우는 전극이 끊어지거나 저항이 175%나 증가했지만, 하이브리드 잉크를 사용했을 때는 16.5% 증가했다.

• Korean Journal of Plant Taxonomy
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• 제39권1호
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• pp.12-23
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• 2009

To verify hybridity of Asplenium castaneo-viride, external morphology, spore morphology, anatomy and chromosomes of the species and of the two presumed parental species, A. incisum and A. ruprechtii, were examined. A. castaneo-viride usually had 1-pinnately divided frond. However, some individuals had almost simple fronds with pinnatisect basal parts similar to A. ruprechtii, while others had fronds similar to A. incisum in having oblanceolate blades and basal pinnae with triangular, 2-3 lobed apices. On the surface of the spores, sculpturing consisted of folds that were usually prominent; forming long wings, and irregular or incomplete reticulation. However, reticulation patterns varied among species. A. castaneo-viride showed a wide range of variation from sparse to dense patterns, whereas A. incisum showed only from sparse to intermediate patterns. A. ruprechtii showed from intermediate to dense patterns. The spore size of A. castaneo-viride was $54.63{\mu}m$, larger than other two species ($47.81{\mu}m$ in A. incisum and $44.22{\mu}m$ in A. ruprechtii). The level of undulation of epidermal cell wall was also different. A. incisum had the most shallowly undulated wall, and A. castaneo-viride had a pattern intermediate between the two presumed parental species. This same patterns was recognized in the density of stomata. The density of $45.91/mm^2$ in A. castaneo-viride was intermediate between the two presumed parental species ($67.00/mm^2$ in A. incisum, and $37.86/mm^2$ in A. ruprechtii). Chromosome number was constant (2x =2n = 72) as in A. incisum and A. ruprechtii. However, A. castaneo-viride showed a different ploidy level. The populations of Mt. Mai (Jeonbuk province) and Mt. Duryun (Jeonnam province) were diploid (2n = 72) which is a new record for this taxon, whereas the population of Mt. Buram (Seoul) was tetraploid (2n = 144). Conclusively, A. castaneo-viride was revealed to be a hybrid of A. ruprechtii and A. incisum based on evidence involving leaves, spores, epidermal cells, stomata and chromosome number.

• Korean Journal of Plant Resources
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• 제13권1호
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• pp.66-79
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• 2000

Anatomical characters such as stem, leaf, ovary, calyx lobe, ultrastructure of stigma, epidermis of leaf blade and midvein, corolla lobe, nectary, seed coat and pollen were examined on 6 taxa of Korean Ophelia, including 5 taxa distributed in south Korea and one taxon considered to be the variation type of Ophelia wilfordi, in order to clarify the limits of intersection and interspecies and to establish the taxonomic position. One taxon distributed in north Korea was also included in the description of species by observation of herbarium specimen of the University of Tokyo in Japan. The two sections were successfully distinguished by internal structure of ovary, morphology of nectary, surface sculpturing of corolla lobe and pollen, ultrastructure of seed and seed coat, which were useful characters to distinguish taxa higher than species. The variation type of Ophelia wilfordi was not distinguished with other species except for absent or present of purple spot in corolla lobe.