• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2001.11a
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• pp.15-18
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• 2001

In this paper, we investigate the rotordynamic characteristics of turbopump system for 9.5ton thrust liquid rocket engine. A finite element method is used to analyze the vibratior characteristics of a rotor-bearing system. The turbopump rotating system is modeled by shaft with sixty elements, nine rigid disks, four ball bearings and four floating ring seals. The calculation results show that the margin of 1st critical speed is increased from 12% to 68% by use of elastic damping ring. In addition, the margin of the 2nd critical speed near the operating speed is increased from 30% to 63% by the stiffness and damping of floating ring seals.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.12
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• pp.1347-1353
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• 2004

With respect to the researches of the optical flying head(OFH) , the head-gimbal assembly should be analyzed to guarantee the stable fabrication and the characteristics of shock resistance. The suitable design is proved through the Probabilistic analysis of the design parameters and material properties of the model. Probabilistic analysis is a technique that be used to assess the effect of uncertain input parameters and assumptions on your analysis model. Using a probabilistic analysis you can find out how much the results of a finite elements analysis are affected by uncertainties in the model. Another factor is analysis of the dynamic shock analysis. For the mobile application, one of the important requirements is durability under severe environmental condition, especially, resistance to mechanical shock. An important challenge in the disk recording is to improve disk drive robustness in shock environments. If the system comes in contact with outer shock disturbance. the system gets critical damage in head-gimbal assembly or disk. This paper describes probabilistic and dynamic shock analysis of head-gimbal assembly in micro MO drives using OFH slider.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.841-849
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• 2013

The aim of this study was to investigate the quality characteristics of Kimchi, prepared with seasoning fluid, vinegar, and mustard extract to inhibit the proliferation of microorganisms and extend the edible period during fermentation at $25^{\circ}C$. We also added perilla leaf, endive, and mustard leaf to Kimchi to improve the flavor. The pH of control Kimchi fluid over 1 day after Kimchi processing, was $5.40{\pm}0.01$ and that of the experimental groups in which vinegar and mustard extract were added was $4.51{\pm}0.01{\sim}4.52{\pm}0.01$, which was lower than that of the control. As the fermentation progresses, the pH of the control decreased rapidly and that of the experimental groups decreased slowly. The initial titratible acidity of the control was low and 3 days later reached $0.95{\pm}0.04$. However, that of the experimental groups was $0.42{\pm}0.01{\sim}0.43{\pm}0.02$ and 5 days later reached a level similar to that of the control. The salinities of the Kimchi juice of both the control and the experimental groups were $2.67{\pm}0.06{\sim}2.80{\pm}0.10$% after 1 day and decreased during fermentation. The amount of lactic acid bacteria of the control was $8.17{\pm}4.01{\times}10^8cfu/g$, 1 day after the Kimchi processing and that of the experimental groups was $2.70{\pm}2.08{\times}10^7{\sim}3.63{\pm}2.80{\times}10^7cfu/g$. After 3 days, these were $3.13{\pm}1.94{\times}10^{11}cfu/g$ and $2.47{\pm}2.23{\times}10^9{\sim}8.03{\pm}3.71{\times}10^9cfu/g$, respectively. According to the result of sensory evaluation, throughout the entire period of the experiment, all sensory items such as color, odor, taste, texture, and total acceptability of the experimental groups were better than those of the control group (p<0.05). Especially, Kimchi in which perilla leaf was added was the best. With the addition of vinegar and mustard extract to the Kimchi, microorganism proliferation was inhibited and the edible period was extended. The minerals, vitamins and antioxidants of leaf vegetables could therefore be obtained.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.4
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• pp.28-38
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• 2018

The purpose of this study is to clarify what is the unique garden making methods of Enshu Kobori by surveying and analyzing that existing garden of Enshu Kobori is different from the existing Japanese garden that had been built up to such a period. Enshu Kobori breaks away from the conventional frame that was established with the gardens of existing Karesansui style(枯山水樣式) with the materials of rocks and sands. Enshu Kobori is produced to make harmony with the rocks by trimming the Rhododendron indicum and this type of making method of Enshu was originated from the aesthetic principle of kireisabi. Due to this type of cause, the garden of Enshu Kobori displays splendid and yet a simple beauty of gardening. With respect to the establishment of a garden unique to Enshu Kobori as such, it seemed to have the cultural background expanded with the cultural perception and official family class of the edo period where it strived for new things. Therefore, Enshu Kobori was designed as the ornament-oriented garden rather than the garden that requires direct ceremonial act. The subject sites for this study are Raikyuji, Daichiji, Shodenji, Nanzenji Hojo and Konchiin as intended by Enshu Kobori. Contents of the study contemplate the location of garden, factors to introduce the garden, structure of garden, background of garden, use of stones, plants and scenic views to clarify the uniqueness of the Enshu Kobori garden.

• Korean journal of applied entomology
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• v.48 no.2
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• pp.263-268
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• 2009

The acaricidal activities of Illicium verum fruit-derived materials against adults of Dermanyssus gallinae were examined using the direct contact application method. Based on laboratory tests, an acaricidal constituent of I. verum fruit was determined because of its potent activity. Results were compared with those of the currently used acaricides such as dichlorvos, diazinon, and carbaryl. The acaricidal principle of I. verum fruit was identified as (E)-anethole using a GC-MS. lts acaricidal activity was compared with those of 12 compounds having a similar chemical moiety. Based on the $LD_{50}$ values, the acaricidal activities of (+)-or-(-)-neomenthol were the strongest (0.01 $mg/cm^2$) and (E)-anethole, (+)-or-(-)-menthol, (${\pm}$)-isoborneol, (-)-menthone, and (lS)-endo-(-)-bomeol showed similar results (0.02 $mg/cm^2$), and (1R)-(+)-camphor and (+)-menthone also gave good activities (0.03 and 0.04 $mg/cm^2$, respectively). These compounds showed more toxic acaricidal activities than diazinon and carbaryl, 0.05 and > 0.2 $mg/cm^2$, respectively, but were not comparable to that of dichlorvos with 0.0002 $mg/cm^2$. These results indicate that the I. verum fruit-derived materials and tested compounds descried as poultry red mites-control agents could be useful for managing field populations of D. gallinae.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.1
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• pp.229-234
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• 1999

We analyzed the reliability characteristics in platinum schottky diodes with variations of n-type silicon substrates concentrations and temperature variations of measurements. The parameters of reliability measurement analysis are saturation current. turn-on voltage and ideality factor in the forward bias, the breakdown voltage in the reverse bias with device shapes. The shape of devices are square type and long rectangular type for edge effect. As a result, we analyzed that the forward turn-on voltage, barrier height, dynamic resistance and reverse breakdown voltage were decreased but ideality factor and saturation current were increased by increased concentration in platinum and n-silicon junction parts. In measurement temperature(RT, $50^{\circ}C$, $75^{\circ}C$), the extracted electrical parameter values of reliability characteristics were increased at the higher temperature under the forward and reverse bias. The long rectangular type devices were more decreased than the square type in reverse breakdown voltage by tunneling effects of edge part.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.314-321
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• 2007

This study was conducted to select leaf vegetables suitable for cultivation in apartment verandas and simple and easy fertigation method for home gardening. In order to develop the convenient fertigation method, hydroponics, wick irrigation, and overhead irrigation methods were compared. For the wick irrigation, two types of nutrient sources were used; one was slow release fertilizers mixed with medium and the other one was nutrient solution filled in container located under pots. The growth of leafy lettuce, leaf mustard, and leaf beet was better in both of the wick irrigation methods rather than in overhead irrigation and hydroponics. The wick irrigation method is very easy, so that it is expected to bring a good result from the cultivating and managing point of view, if it brings with commercialized system along with slow release fertilizer. As a result of investigation of environment such as temperature, relative humidity, and irradiance level in apartment verandas in autumn the highest irradiance level during a day was just 48% and 35% in verandas facing south and feeing southeast, respectively, comparing to that in greenhouse. The light environment was investigated as a limiting factor for vegetable growing in verandas. Therefore, to select the vegetables showing good growth under low irradiance environment, nine leaf vegetables such as romaine lettuce, lent lettuce, head lettuce, endive, pak-choi, leaf mustard, garland chrysanthemum, leaf beet, and Chinese chive were grown under 0%, 50%, 70%, 90% shading. Among them, Chinese chive showed the best growth under low irradiance levels. Endive showed line growth reduction according to shading degree, however, even under 90% shading condition, it showed good growth. And then leafy lettuce, garland chrysanthemum, and pak-choi followed. Therefore, these results will be of help in selecting vegetables for veranda gardening with different light levels.

• Research in Plant Disease
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• v.26 no.4
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• pp.272-278
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• 2020

The severe lettuce damage caused by Paratylenchus projectus was first reported in 2019 in Korea. To find high-value rotation crops for the control of P. projectus, nine vegetables, Brassica juncea (leaf mustard), B. rapa subsp. nipposinica (kyona), B. oleracea var. italica (broccoli), B. rapa subsp. chinensis (bok choy), B. oleracea var. viridis (kale), B. oleracea var. gongylodes (kohlrabi), Cichorium endivia (endive), C. intybus (chicory), Ipomoea aquatica (morning glory) were planted in d-10-cm clay pots in greenhouse. The growth of vegetables was compared between inoculated with 3,000 P. projectus per 100 ㎤ of soil and non-inoculated. Treatments were replicated 10 times. After 100 days, the reduction of fresh top weight was 30.4% in C. intybus, 35.1% in I. aquatica, 36.9% in B. oleracea var. acephala, 40.5% in C. endivia, 42.1% in B. rapa, 47.5% in B. rapa subsp. nipposinica, 50.4% in B. oleracea var. gonglodes, 56.3% in B. oleracea var. italica, and 66.0% in B. juncea. Nematode multiplication rates (Pf/Pi) were lower in I. aquatica (0.64) and C. endivia (1.1), but higher in B. oleracea var. gongylodes (2.54). Considering these results, I. aquatica is suitable for the rotation crop with lettuce until better rotation crops developed.

• Research in Plant Disease
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• v.19 no.4
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• pp.294-299
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• 2013

To select resistant vegetables against two species of root-knot nematodes, M. incognita and M. arenaria, 39 vegetables belongs to 7 families, 13 genera, 25 species were screened in greenhouse pot test. Susceptible vegetables to both nematodes were amarath and leaf beet in Amaranthaceae, Malabar spinach in Basellaceae, Moroheiya in Tiliaceae, and Water-convolvulus in Convolvulaceae, Pak-choi in Brassica campestris var. chinensis, Tah tasai in B. campestris var. narinosa, B. campestris var. chinensis x narinosa, Leaf mustard, Mustard green in B. juncea, Kyona in B. juncea var. laciniate, Choy sum in B. rapa subsp. arachinenesis, Kairan in B. oleracea var. alboglabra, Arugula in Eruca sativa, Garland chrysanthemum in Chrysanthemum coronarium, Endive in Cichorium endivia, Artichoke in Cynara cardunculus var. scolymus, Lettuce in Lactuca sativa. Resistant to M. arenaria but susceptible to M. incognita were B. oleracea cv. Matjjang kale, B. oleracea var. gongyloides cv. Jeok kohlrabi, and C. intybus cv. Radicchio. Resistant vegetables to both nematodes were C. intybus cv. Sugar loaf, Grumoro, Radichio treviso, B. oleracea cv. Manchu collard, Super matjjang, B. oleracea italica, B. oleracea var. botrytis italiana, and Perilla in Lamiaceae. Vegetables resistant to both species of root-knot nematodes could be used as high-valued rotation crops in greenhouses where root-knot nematodes are problem.

• Journal of Life Science
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• v.13 no.6
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• pp.764-774
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• 2003

The edible plants sold at the market in Busan were classified into 8 divisions, 11 classes, 46 orders, 67 families, 156 genera, 183 species and 45 varieties, and a total of 228 kinds of plants were included in them. Among the 228 kinds of edible plants, Angiospermae were the highest number of 202 kinds (88.60%), and next came Fungi of 9 kinds (3.95%), Phaeophyta of 5 kinds (2.19%), Rhodophyta of 4 kinds (1.75%), Pteridophyta of 3 kinds (1.32%) Gymnospermae of 2 kinds (0.88%), Chlorophyta of 2 kinds (0.88%), and Lichenes of 1 kind (0.44%) in order In the taxon of family, Cruciferae, Rosaceae, Leguminoceae, Cucurbitaceae, Umbelliferae, Compositae, Liliaceae, and Gramineae include many species. In the taxon of genus, Brassica(14 species), Prunus(9), Lactuca(9), Allium(7), Citrus(5), Cucumis(4), Cichorium(4) in order contain many species. Among tile edible plants, Chamjuknamu(Cedrela sinensis) is wrongly named Gajuknamu(Ailanthns altissima). And there are others which are called in a wrong way: Endive is wrongly called Chicory, Saeneutaribeoseot, Saesongi and Padeudeknamul(Japanese hornwort), Chamnamul. Gyul and Milgam, Geumgam and Gamgyul, Banana and Pacho, Paprika and Pimang(Pimento) are the names of the same plants. The number of the kinds of edible plants is different in each season. Fall has the most edible plants, and it is followed by spring, summer and winter. The edible parts of plants which are sold at the market are leaves, young sprouts, fruits, grains, roots, stems and petioles.