• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.5
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• pp.97-103
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• 2011

This study is numerical analysis on flow characteristic in a standard cyclone dust separator. The cyclone dust separator is widely used in a industrial applications as a method for dust removed from gases. In cyclone chamber, a very complex flow field is formed, involving the interaction between highly swirling velocity and turbulent field. Numerical analysis with computational fluid dynamics(CFD) was carried out to investigate the working fluid that flow into cyclone dust separator. Helical entry type was increasing flow rate compared with tangent entry type. And according to increasing pressure difference was increased fan power. But, helical entry type was high performance dust separator, in comparison with tangent entry type.

• Journal of Agricultural Extension & Community Development
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• v.22 no.1
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• pp.15-24
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• 2015

Responsible tourism attracting worldwide attention has supported local economy and community development as a type of alternative tourism. This study explored the perception toward fairness in tourism and operation status of responsible tour operators in South Korea by conducting in-depth interviews with probe questions. Ten responsible tour operators were interviewed with a semi-structured interview questionnaire for one upto two hours. From the interview data, six themes were identified as difficulties of responsible tour operators: lack of manpower, advertising and promotion, absence of marketing strategy, regulation, lack of budget and lack of recognition of responsible tourism. As government support identified through the interviews, there are the followings seven themes: a low entry barrier market, investment in human resources, resource utilization, community-based policies, connection with local produce, community support and connection system of responsible travel agencies with intermediate support organizations at a local level, The findings of this paper implicate the underlying subject of responsible tourism from a tour operators' perspective.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.388-395
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• 2019

The purpose of this study is to suggest structural model and analyze design factors for the development of small greenhouse standardization model. The average dimensions of small greenhouse desired by urban farmers were 3.3m in width, 1.9m in eaves height, 2.7m in ridge height, 5.7m in length. The cladding materials for small greenhouse were preferred to glass, PC board and plastic film, framework to aluminum alloy and steel, and heating method in electrical energy. In addition, it was analyzed that small greenhouses need to develop structural model by dividing them into entry-level type and high-level type. The roof type that was used for entry-level type was arch shape, framework was steel pipe, cladding material was plastic film. On the other hand, high-level type was used in even span or dutch light type, framework with square hollow steel, cladding materials with glass or PC board. In consideration of these findings and practicality, this study developed four types of small greenhouses. The width, eaves height, ridges height, and length of the small greenhouses of even span type, which were covered with 5mm thick glass and 6mm thick PC board were 3m, 2.2m, 2.9m, and 6m, respectively. The small greenhouse of dutch light type covered with 5mm thick glass was designed with 3.8m in with, 2.2m in eaves height, 2.9m in ridges height, and 6m in length. The width, eaves height, ridges height, and length of the arch shape small greenhouse covered with a 0.15mm PO film were 3m, 1.5m, 2.8m, and 6m, respectively.

• Korean Journal of Heritage: History & Science
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• v.55 no.1
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• pp.5-34
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• 2022

The purpose of this study is to investigate the unique contrasting landscape characteristics of imperial tombs of Qing dynasty by examining the characteristics of facility layout in which location, Feng shui, and siblings are harmonized with the 12 Qing Dynasty Hwanggyeongchim. Through literature surveys, field observation and interviews, videos and drawing comparison, and inductive contrast analysis, the contrasting landscape characteristics of imperial tombs in the Qing Dynasty were analyzed by classifying them into natural environment, location, Feng shui, and formal esthetics. As a result, the characteristics of the location type and the layout plan of the Qing dynasty imperial tombs were derived from the analysis of Feng shui shape, axis extension distance along the midaxial line, the width of the ridge, the formality of the facility layout according to the difference between the height of the starting point and the end point, the leftward direction of the tomb, and the space ratio of the 'entry space' - 'ritual space' - 'burial mound space', etc. In addition, it was possible to derive the facility arrangement characteristics of tombstones through the analysis of the types and the arrangement order of tombs facilities, as well as the distribution, quantity and types of stone figures, while also revealing some contrasting characteristics different from those of the Ming Dynasty. In addition, it was confirmed that the spatial division effect through the water system and the view effect of the view from the midaxial line and the vista are the representative view effect found in the Qing Dynasty imperial tombs along with the density contrast.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.298-308
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• 2009

A flexuous rod-shaped virus was isolated from Cucurbita pepo leaves showing as green mosaic and puckering symptoms at Anseong, Korea. Based on the biological analysis, electron microscopy, and reverse transcription-polymerase chain reaction (RT-PCR), the virus isolate was identified as Papaya ringspot virus type watermelon (PRSV-W). From biological analysis, the host range of PRSV-W was limited to the families Cucurbitaceae and Chenopodiaceae. Most susceptible cucurbit species, such as Cucumis lanatus, Cucumis sativus, Cucurbita pepo, and Citrullus lanatus, showed symptoms of green mosaic, malformation, puckering, and narrow laminae by infection with PRSV-W. The local lesion were showed on the inoculated leaves of both Chenopodium amaranticolor and C. quinoa. Field survey of PRSV, Watermelon mosaic virus (WMV) and Zucchini yellow mosaic virus (ZYMV), three major viruses infecting cucurbit, was done during 2001 to 2003 on 173 commercial cucurbit cultivating fields distributed over the three regions of Gyeonggi, Gyeongbuk and Jeonnam Provinces where cucurbits are grown in different environmental conditions and cropping patterns. Typical viral symptoms were observed from 107 cultivating fields, and all three kinds of potyviruses were detected from 206 samples out of the 235 samples using RT-PCR. Watermelon mosaic virus (WMV) and Zucchini yellow mosaic virus (ZYMV) are the most widely distributed viruses in outdoor and retarding-culture fields, at an infection rating of 48 and 33 percents, respectively. PRSV was detected from 12 percent of 235 samples. The nucleotide and amino acid sequences of coat proteins (CP) of eight PRSV isolates, collected from several areas including Anseong, were determined and sequenced heterogeneity among the isolates was performed. The CP gene of PRSV showed 88.6~97.3 percent homology in nucleotide sequences and 95.1~99.3 percent homology in amino acid sequences with other PRSV isolates worldwide. The phylogenetic analysis indicated that the Korean PRSV isolates belong to the southern-east Asian cluster.