• Title/Summary/Keyword: 겹이음

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Calculation of Wave Resistance for a Submerged Body by a Higher Order Panel Method (고차 판요소법을 이용한 몰수체의 조파저항 계산)

  • Chang-Gu Kang;Se-Eun Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.29 no.4
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    • pp.58-65
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    • 1992
  • In this paper, wave resistance for a submerged body is calculated by a higher order panel method. The Neumann-Kelvin problem is solved by the source or normal dipole distribution method. The body surface is represented by a bicubic B-spline and the singularity strengths are approximated by a bilinear form. The results calculated by the higher order panel method are compared with those by the lowest order panel method developed by Hess & Smith. The convergence rate of the higher order panel method is much better than the lowest order panel method. But the wave resistance calculated by the higher order panel method still shows discrepancy with an analytic solution at low Froude number like that by the lowest order panel method.

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Effects of Shading and Mixing Ratio of Recycling Spawn bed Logs on the Yield of Gastrodia elata Blume (차광정도와 접종목 흔용이 천마의 수량에 미치는 영향)

  • Kwon, Young-Hwan;Lee, Jeong-Dong;Jung, Do-Chul;Yoon, Se-Jin;Hwang, Young-Hyun
    • Korean Journal of Plant Resources
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    • v.18 no.3
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    • pp.512-517
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    • 2005
  • To establish the economical cultivation method of Gastrodia elata Blume by controlling the shading rate and the mixing ratio of recycling spawn bed logs, a serial experiment was carried out. When G. elata was grown in the field with no shading, the yield of spawn tuber was higher than that of tuber of G. elata. The yield of G. elata was high in the rainproof green house covered with one layer of $95\%$ shading net, in the rainproof green house covered with two layers of $95\%$ shading net, and in the field with no shading, in that order. In the case of mixing ratio of recycling spawn bed logs, the yield was high in the fresh logs, in the mixing ratio of 2:1, and the ratio of 1:1, in that order. The income of the rainproof green house covered with one layer of $ 95\%$ shading net which brought the best yield was $81\%$ in the mixing ratio of 2:1 over the fresh logs.

Experimental Study on the Flexural Performance of Steel Beams Reinforced by AFRP Sheets (아라미드 섬유 쉬트를 이용한 철골 보 부재의 휨 보강 성능에 관한 실험적 연구)

  • Kim, Kang Seok;Nah, Hwan Seon;Kim, Kang Sik;Lee, Hyeon Ju;Lee, Kang Min
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.2
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    • pp.61-69
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    • 2011
  • Fiber Reinforced Plastic (FRP) sheets have been widely used to retrofit and rehabilitate RC structures, while in case of retrofitting steel structures, there are no codes and researches. It stems from configuration of member and characteristics of bonding behavior. This study focused on the static behavior of steel beams reinforcement by AFRP sheets. The main objective of the experimental programme was the evaluation of the force transfer mechanism, the increment of the beam load carrying capacity and the bending stiffness. A bending test was conducted on a H-shaped steel beam, with aramid FRP sheets bonded to its flanges. The mid-span deflection and the strain from three points along AFRP sheets were recorded Test results exhibit that the increment of the load-carrying capacity with reference to a mid-span deflection level of 15 mm(1/125mm of the clear span) was equal to 9.4% and for the two layers case, an elastic stiffness increment is slightly higher than one layer case.

A taxonomic study on six section subgenus Vigena Nees of Carex L. (Cyperaceae) in Korea (한국산 괭이사초아속(subgen. Vignea Nees) 6절의 분류 형질에 관한 연구)

  • Oh, Yong Cha;Jo, Mi Jung
    • Korean Journal of Plant Taxonomy
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    • v.33 no.3
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    • pp.227-253
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    • 2003
  • Morphological characters of C. kobomugi, C. gibba, C. echinata. C. remotiuscula. C. maakii. C. curta, and C. loliacea of genus Carex were rexamined. The epidermal patterns of perigynium, achene and leaf were investigated using by a scanning electron microscope(SEM) and a light microscope(LM). Morphological characters. such as length and width of stem and leaf, sheath, bract, spike, scale, perigynium, beak of perigynium, length of spike peduncle, size, and frequency of stomatal complex of leaf, number of bract, shape of stem transection, scale and apex of scale, beak and base of perigynium, achene, epidermal cell and cell wall of perigynium, achene, leaf epidermal patterns (fundamental epidermal cell and cell wall, silica body, subsidiary cell), hair, papillae, prickle present/absent of perigynium and leaf were useful for the identification of observed seven taxa. Examined six taxa of section Macrocephalae, Gibbae, Stellulatae, Elongatae, Ovales, and Heleonates were distint from each other with respect of length and width stem, leaf, bract, perigynium, perigynium beak, lenght of spike peduncle, perigynium, and leaf. A key based on data was presented here.

Effect of Shading Level of Nursing Bed on the Shoot Growth of Rooted Cuttings in Native Hydrangea serrata for. acuminata (육묘상의 차광정도가 자생 산수국 삽목묘의 신초생장에 미치는 영향)

  • Lee, Seung Youn;Lee, Sung Chun;Park, Sung Tae;Rhee, Jung Chul;Lee, Taek Joo;Kim, Kwang Jin;Lee, Jeong Sik
    • FLOWER RESEARCH JOURNAL
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    • v.16 no.3
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    • pp.153-160
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    • 2008
  • This experiment was conducted to find out an adequate shading level (0, 55, 74, and 95%) on the shoot growth of rooted cuttings of native Hydrangea serrata for. acuminata. New shoot height (NSH), length and width of leaf, and stem diameter under 55% shading were the greatest. Net photosynthetic rate under 55% shading was the greatest, while intercellular $CO_2$ concentration was the least in this treatment. The greatest content of photosynthetic pigments (total chlorophyll, carotenoid) was observed in leaves grown under a 74%, followed by a 55% shading level. Leaf stomata were observed on the abaxial surface, but those on adaxial surface in all shading treatments were not observed. In 95% shading, decreased stomatal density and development were observed. Higher stomatal density and development, however, were observed in 55% shading. Therefore, it is concluded that a 55% shading level was the optimum for growth of new shoots of rooted cuttings of native H. serrata for. acuminata.

An Improvement of the Stability of Plane Journal Bearing using Leaf Spring Damper (겹판스프링댐퍼를 이용한 저어널베어링의 안정성 향상)

  • 김종수;최영준;제양규
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2000.06a
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    • pp.87-92
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    • 2000
  • In order to improve the instability of Plane journal bearing, it is introduced the leaf spring damper(LSD). The effects of dynamic characteristics of LSD on the stability of a plane journal bearing were investigated theoretically. The improvements on the stability of a plane journal bearing with LSD. are compared with the results of a floating ring journal bearing and of journal bearing without LSD. It found that a plane journal bearing with LSD will be an effective way in the improvement on the stability of rotor system.

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Control of Damping Forces by Side Clearance in Leaf Spring Damper (겹판스프링댐퍼에서 측면틈새에 의한 감쇠력 조절)

  • 김종수;김상도;제양규
    • Tribology and Lubricants
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    • v.16 no.1
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    • pp.27-32
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    • 2000
  • This paper describes that the leaf spring damper (LSD) developed by authors can be controled by side clearance between side covers and leaf springs. The test rig and two prototype dampers with different side clearance were manufactured. Experiments were performed to investigate the effects of side clearance on the damping of the leaf spring damper. The stiffness and damping coefficients are obtained from the displacements and the reaction forces generated by rotating the eccentric shaft. All dynamic coefficients are plotted with the excitation frequency which is adjusted by rotating speed of the shaft.

Extraction of the Training Data for Building Case Frames from a Corpus (말뭉치로부터 격틀 구축에 필요한 학습 데이터 추출)

  • Yang, Dan-Hee;Song, Man-Suk
    • Annual Conference on Human and Language Technology
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    • 1998.10c
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    • pp.287-292
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    • 1998
  • 실용적인 격틀(Case frame) 정보를 말뭉치로부터 자동구축하기 위해서는 대량의 홀문장이 필요하다. 그리고 국어 문장 형식은 영어와 많은 차이점이 있다. 또한 기존의 격틀 구축 연구에서 전제했던 광범위한 학습 데이터와 언어학적 지식은 국어에 대해 현재 존재하지 않는다. 그러므로 본 연구는 그러한 문제점들을 밝히고 현실적인 접근 방법을 제시한다. 그리고 겹문장을 홑문장 형태의 문장들로 바꾸기 위한 알고리즘을 제시한다.

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진동.소음이 구조물 및 근무환경에 미치는 영향

  • 이정수
    • Journal of the KSME
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    • v.27 no.2
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    • pp.109-112
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    • 1987
  • 산업이 고도화 되면서 기계장비의 중량화와 고속화가 가속되어지고 있으며, 이로 인하여 과다한 진동과 소음을 유발시키고 있다. 특히 교통량이 많은 도로변의 건물 및 주택가에 소음공해가 심하며, 고속도로 및 철도연변의 건물 및 주택가는 비록 차음벽을 설치하여 많은 소음을 차단해 주지만 미흡한 상태다. 또한 철도 진동이 주위 건물 기초로 전파하여 건물의 진동을 유발하여 건물벽체가 갈라짐의 원인이 될 수 있다. 따라서, 교통 소음이 심한 장소에서는 차음율이 높은 재료를 사용하여 공기음을 차단하며, 건물의 유리창은 가능한 한 2겹유리(pair glass)를 사용한다. 또한 철도 연변의 건물기초는 베어링 페드를 사용하여 지반으로 전파되는 진동을 차단하여 줌으로써 안락한 주거환경 및 근무환경을 조성하리라 생각한다.

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