• Title/Summary/Keyword: 이중봉

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Flora and Classification by Characteristics of Nature Every Second Year in Wolchulsan National Park (월출산국립공원 자연휴식년제 구간의 식물현황과 특성별 분류)

  • Oh, Hyun-Kyung;Beon, Mu-Sup
    • Korean Journal of Plant Resources
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    • v.20 no.2
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    • pp.201-211
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    • 2007
  • The vascular plants at the nature every second year in Wolchulsan National Park was listed 325 taxa: 86 families, 205 genera, 283 species, 1 subspecies, 36 varieties and 5 forms. Based on the list of the rare plants by the Forest Research Institute, 3 taxa were recorded in the studied areas; Lilium callosum (Preservation priority order; No. 191), Viola albida (No. 202), Wikstroemia trichotoma (No. 120) and based on the list of Korean endemic plants, 8 taxa were recorded; Carex okamotoi, Lilium amabile, Carpinus coreana, Clematis trichotoma, Stewartia koreana, Ajuga spectabilis, Weigela subsessilis, Adenophora triphylla var. hirsute. Specific plants by floral region were total 44 taxa; Prunus davidiana, Wistaria floribunda in class IV, 9 taxa (Neolitsea aciculata, Vaccinium bracteatum, Utricularia racemosa, etc.) in class III, 5 taxa (Bupleurum longiradiatum, Ostericum melanotilingia, Cirsium schantarense) in class II, 28 taxa (Polygonatum falcatum, Eurya japonica, Ajuga spectabilis, etc.) in class I. The naturalized plants in this site were 4 families, 6 genera, 9 taxa and naturalization rate was 2.8% of all 325 taxa vascular plants.

Studies on Resource Plants of the Mireukbong and Manduksan in Jeollabuk-do (전라북도 만덕산과 미륵봉 일대의 자원식물상 연구)

  • Kim, Young-Ha;Beon, Mu-Sup;Oh, Hyun-Kyung
    • Korean Journal of Plant Resources
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    • v.19 no.4
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    • pp.447-458
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    • 2006
  • The resource plants at the Manduksan and Mireukbong was listed 550 taxa: 107 families, 339 genera, 481 species, 1 subspecies, 65 varieties and 3 forms. Among 550 taxa listed was confirmed 323 taxa of edible plants (58.7%), 384 taxa of medicinal plants (69.8%), 267 taxa of ornamental plants (48.5%) and 268 taxa of the others (48.7%). Based on the list of the rare plants by the Forest Research Institute, 4 taxa were recorded in the studied areas; Lilium distichum (Preservation priority order: No. 159), Tricyrtis dilatata (No. 97), Aristolochia contorta (No. 151), Prunus yedoensis (No. 110) and based on the list of Korean endemic plants, 11 taxa were recorded; Cephalotaxus koreana, Carex okamotoi, Lilium amabile, Populus tomentiglandulosa, Salix purpurea var. japonica, Pseudostellaria multiflora, Prunus yedoensis, Forsythia koreana, Paulownia coreana, Weigela subsessilis, Aster koraiensis. Specific plant species by floral region were total 30 taxa; Prunus yedoensis in class V, Wistaria floribunda in class IV, 3 taxa (Spiraea salicifolia, Acer palmatum, Asperula lasiantha) in class III, 3 taxa (Potentilla dickinsii, Viola tokubuchiana var. takedana, Caryopteris incana) in class II, 22 taxa (Pinus koraiensis, Hosta capitata, Chloranthus japonicus, Salix glandulosa, Juglans mandshurica, etc.) in class I. This site needs urgent countermeasures, because there have increased many man-made damages like planting exotic plants, picking wild plants and soil compaction induced by human trampling.

Vibration Analysis of Beam Supported by Plate Type Springs Considering a Contact (접촉해석이 연계된 판형 스프링 지지보의 진동해석)

  • 최명환;강흥석;윤경호;송기남
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.5
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    • pp.384-392
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    • 2003
  • The fuel rods in the Pressurized water reactor are continuously supported by a spring system called a spacer grid which is one of the main structural components for the fuel rod cluster(fuel assembly). The fuel rods vibrate within the reactor due to coolant flow. Since the vibration, which is called flow-induced vibration(FIV) can wear away the surface of the fuel rod, it is important to understand it's vibration characteristics. In this paper, the vibration analyses and the tests for the dummy rods supported by New Doublet(ND) spacer grids are described. A new FE model which reflects the contact area between the rod and ND spacer grid spring is developed to replace the previous one by which a good agreement could not be obtained with the vibration test. The natural frequency and mode shape calculated by both the Previous FE model and the new one are compared with those of experiment for a single-spanned rod supported by two ND spacer grids. The results of the new model showed good agreement with the experiment compared with those of previous model. In addition. the new FE model is applied to the vibration analysis for the dummy rod of 2.189 mm tall continuously supported by five ND spacer grids. It is also obtained that the analysis results of the new FE model well agreed to experiment ones as the single-spanned rod.

Screening for Antagonistic Plants for Control of Phytophthora spp. in Soil (토양중(土壤中)의 Phytophthora spp. 방제(防除)를 위한 길항식물(桔抗植物)의 탐색)

  • Paik, Su-Bong
    • The Korean Journal of Mycology
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    • v.17 no.1
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    • pp.39-47
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    • 1989
  • Among 100 species in 54 families of plants tested, leaf extracts from Allium cepa, Allium sativum, Malussieboldii, Reynoutria japonia and Rheum coreanum were inhibitory on mycelium growth of phytophthora spp.. Especially, Allium sativum and Malus sieboldii were strongly inhibitory. Allium sativum, Malussieboldii and Rhem coreanum were strongly inhibitory on zoosporangium germination of P. capsici. Malus sieboldii only were strongly inhibitory on zoosporangium germination of P. nicotiana and P. infestans.And Malus sieboldii were strongly effected on disease control of these pathogens. These results indicate the possibility of finding antagonistic plants in the nature for the control of certain pathogens in soil.

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Oil-Air Lubrication Characteristics of a High Speed Spindle System for Machine Tools(I) Effect of Oil Supply Rate, Rotational Spindle Speed and Spindle System Structure (공작기계용 고속주축계의 오일에어윤활특성에 관한 연구 (I) 공급유량, 주축회전수 및 주축계 구조의 영향)

  • 김석일;최대봉;박경호
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.2
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    • pp.351-358
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    • 1993
  • Recently a high speed spindle system for machine tools has attracted considerable attention to reduce the machining time, to improve the machining accuracy, to perform the machining of light metals and hard materials and to unite the cutting and grinding processes. In this study, a high speed spindle system is developed by applying the oil-air lubrication method, angular contact ball bearings, injection nozzles with dual orifices and so on. And a lubrication experiment for evaluating the performance of the spindle system is carried out. Especially, in order to establish the lubrication conditions related to the development of a high speed spindle system, the effects of oil supply rate, rotational spindle speed and so on are studied and discussed on the bearing temperature rise, bearing temperature distribution and frictional torque. And the effect of spindle system structure on the bearing temperature distribution is investigated.

Dynamic Stability Analysis of Annular Cylindrical Fuel Rod in Axial Flow (축류에 놓인 환형 실린더 연료봉의 동적 안정성 기초해석)

  • Lee, Kang-Hee;Kim, Hyung-Kyu;Yoon, Kyung-Ho;Lee, Young-Ho;Kim, Jae-Yong
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.264-267
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    • 2008
  • Dual-cooled fuel with inner and outer flow channel was proposed for high burup, next generation nuclear fuel design. The annular cylinder of dual cooled fuel has higher structural strength compared to the conventional one, but also have concerns about flow induced vibration due to an additional flow of inner channel and the difference of flow velocity in between inner and outer channel. In this study, the dynamic stability of flexible, annular cylinder was evaluated according to the flow variation and compared to the that of the conventional PWR fuel rod. Centrifugal and Coriolis force by the additional flow in the inner channel were added in the dynamic equation of flexible beam in uniform, external, and axial flow. Complex eigenfrequency was calculated by the finite element method. Stability margin of annular cylinder compared to the solid cylinder and change of the dynamic characteristic are presented and discussed as a analysis results.

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Analysis of aerosol and cloud depolarization ratios measured by lidar (구름, 에어로솔의 라이다 계측 편광 소멸도 분석)

  • Park, Chan bong;Lee, Young Woo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.10a
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    • pp.442-444
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    • 2012
  • Depolarization characteristics of aerosol and cloud measured by dual wavelengths polarization lidar are examined. Ratio of depolarization ratio (RDR) between 1064 and 532nm are analyzed and compared with spherical aerosols and cloud. RDR of dust aerosols is exponentially decreased according to the increase of depolarization ratio at 532nm. The RDR of spherical aerosol is in the range of 1.5~6, dust aerosol is 0.98~4, and cloud is 0.7~1.77. Vertical distribution of dust aerosol and Relative Humidity (RH) are compared. In general, the RH in the dust layer are in the range of 30~60%. However, higher RH is frequently observed in the dust aerosols layer. In the condition of higher RH over 75%, the RDR of the dust aerosol are also increased to the range of 2~4.

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Vibration Analysis of Beam Supported by Springs Considering a Contact (접촉해석이 연계된 스프링 지지보의 진동해석)

  • 최명환;강홍석;송기남;윤경호;김형규
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.1216-1221
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    • 2002
  • The fuel rods in the pressurized water reactor are continuously supported by a spring system called a spacer grid which is one of the main structural components for the fuel rod cluster (fuel assembly). The fuel rods are vibrating within the reactor due to coolant flow. Since the vibration, what is called flow-induced vibration(FIV), can wear away the surface of the fuel rod, it is important to understand the vibration characteristics of it. In this paper, the vibration analyses and the tests for the dummy rods supported by New Doublet(ND) spacer grids are described. A new FE model which reflects the contact area between the rod and ND spacer grid spring is developed to replace the previous one by which a good agreement could not be obtained with the vibration test. The natural frequency and mode shape calculated by both the previous FE model and the new one are compared with those of experiment fur a single-spanned rod supported by two ND spacer grids. The results by the new model show good agreement to experiment as compared with the ones by previous model. In addition, the new FE model is applied to the vibration analysis fur the dummy rod of 2.19 m tall continuously supported by five ND spacer grids. It is also obtained that the analysis results by the new FE model well agree to experiment ones as the single-spanned rod.

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The Effect of Ingredients on the Hardness of Ginseng Jelly by Response Surface Methodology (반응표면 실험계법에 의한 인삼젤리의 견고성에 미치는 각성분의 영향)

  • Lee, Hyung-Ok;Sung, Hyun-Soon;Suh, Kee-Bong
    • Korean Journal of Food Science and Technology
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    • v.18 no.4
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    • pp.259-263
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    • 1986
  • The effect of ingredients on the hardness of ginseng jelly were studied by response surface methodology and observed by multiple regression equation $({R_A}^2=0.8660)$ and response surface contour. The hardness of ginseng jelly was directly influenced by the order of the contents of glucose > gelatin > sucrose > water > citric acid and it was also affected interactions of water and glucose.

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Dual Sink Nodes for Sink Node Failure in Wireless Sensor Networks (무선 센서 네트워크에서의 싱크노드 실패에 대비한 이중 싱크노드 장치)

  • Kim, Dae-Il;Park, Lae-Jeong;Park, Sung-Wook;Lee, Hyung-Bong;Moon, Jung-Ho;Chung, Tae-Yun
    • IEMEK Journal of Embedded Systems and Applications
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    • v.6 no.6
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    • pp.369-376
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    • 2011
  • Since wireless sensor networks generally have the capability of network recovery, malfunction of a few sensor nodes in a sensor network does not cause a crucial problem paralyzing the sensor network. The malfunction of the sink node, however, is critical. If the sink node of a sensor network stops working, the data collected by sensor nodes cannot be delivered to the gateway because no other sensor nodes can take the place of the sink node. This paper proposes a TDMA-based wireless sensor network equipped with dual sink nodes, with a view to preventing data loss in the case of malfunction of a sink node. A secondary sink node, which synchronizes with a primary sink node and receives data from other sensor nodes in normal situations, takes the role of the primary sink node in the case of malfunction of the primary sink, thereby eliminating the possibility of data loss. The effectiveness of the proposed scheme is demonstrated through experiments.