• Title, Summary, Keyword: 구멍

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A Taxonomic Study on the family Zerconidae (Acari : Mesostigmata) in the Korea (한국산 구멍응애과(중기문목)의 분류와 사육)

  • 이원구;임재원;이인용
    • The Korean Journal of Soil Zoology
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    • v.7 no.1_2
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    • pp.7-16
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    • 2002
  • This study was based on 8 species as follows. Specimens had been collected from 8 localities in Korea from April to September, 2002: Echinozercon orientalis Blaszak, 1975 Eurozercon pacificus Halaskova, 1979 Kaikiozercon mamillosus Halaskova, 1979 Kaikiozercon peregrinus Halaskova, 1979 Koreozercon bacatus Halaskova, 1979 Mesozercon coreanus Blaszak, 1975 Mesozercon plumatus (Aoki, 1966) Zercon szeptyckii Blaszak, 1976 The size of idiosoma and the length of setae on proscrotum and postscrotum were compared with the data of North Korean specimens . Two species (E. orientalis, Z. szeptyckii) are similar, three species (E. orientalis, K. bacatus, M. coreanus) are small but not much different and the rest three species (K. mamillosus, K. peregrinus, M. plumatus) are small and much different in measurements of setae from those of the North Korean specimens.

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Synopsis of the Stargazer Fish, Family Uranoscopidae (Perciformes) from Korea (한국산 통구멍과(농어목) 어류의 분류)

  • 이충렬;주동수
    • The Korean Journal of Zoology
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    • v.38 no.3
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    • pp.364-374
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    • 1995
  • The taxonomic revision of the family Uranoscopidae from Korea was made on the basis of the speciemens collected in the coasts of the Korea from 1986 to 1994. The key to the species and genera for classification of the famiiy Uranoscopidae was provided with synonym and their distributions. The stagazer fishes from Korea are composed of 6 species in 3 genera: Uranoscopus Japonicus, U. bicinctus, U. chinensis, U. tosae, Gnathagnus eolngatus and Ichthyscopus lebeck sannio. The Korean stagazer fishes were widely distributed in the West and South Sea of Korea, but only Ichthyscopus lebeck sannio distributed in the around sea of Cheju Island.

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Pressure-Hole Error (압력구멍 오차)

  • 김광웅
    • The Korean Journal of Rheology
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    • v.1 no.1
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    • pp.5-11
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    • 1989
  • 슬릿트나 관형의 흐름에서 유체의 유변학적 성질을 측정하기 위해서는 벽면에서의 압력구배를 알아야한다. 벽면에서의 압력측정은 특히 관형의 경우 압력구멍의 존자가 불가 피하다. 압력구멍에 의한 오차에 대한 이론적인 고찰이 있었지만 사용된 몇가지 가정이 실 험적인 과찰과 일치하지 않아 이들 이론에 대한 강한 의문을 제기하고 한다. 한편 실험적인 결과는 묽은 고분자 용액인 경우 측정압력에 대한 상대적인 압력구멍 오차가 무시할 수 없 을 정도로 크다. 압력구멍 오차는 압력구멍의 크기, Reynolds 수 (점성) 및 Weissenberg 수 (탄성)의 함수로 나타나고 있다. 그러나 농도가 비교적 높은 고분자 용액이나 용융체는 상대 적으로 무시할 수 있을 정도의 압력구멍 오차를 나타낸다.

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탈이온수를 절연액으로 사용한 깊은 구멍 가공

  • 서동우;이상민;주종남
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.244-244
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    • 2004
  • 다양한 산업 분야에서 세장비가 높은 구멍 가공의 필요성이 증가하고 있다. 방전 가공은 세장비가 높은 미세 구멍을 가공하는데 매우 효과적인 방법이다. 그러나 일반적인 방전 가공으로는 세장비가 5이상 되는 깊은 구멍을 가공하기가 쉽지 않다 구멍을 가공할 때에 일정 깊이 이상으로 가공이 진행되면 가공 부스러기가 쉽게 배출되지 못하여 방전 집중 현상과 아크 방전이 일어나게 된다. 이로 인해 깊은 구멍 가공이 불가능하게 된다. 그러나 절연액에 초음파를 부가하여 가공을 하면 공구와 가공물 사이의 기공 부스러기가 분산되어 방전 집중 현상과 아크 방전 현상이 사라지고 가공이 원활히 이루어진다.(중략)

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Fungal flora of Ullung Island (III) -on some polyporoid fungi- (울릉도의 균류상 (III) -수종의 구멍장이버섯류에 관하여-)

  • Jung, Hack-Sung
    • The Korean Journal of Mycology
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    • v.20 no.1
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    • pp.1-10
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    • 1992
  • Fresh fungi were collected during field trips to Ullung Island from August, 1990, to September, 1991. Among them, some polyporoid fungi were recognized to the species. Thirty three species were identified, among which nine fungi were confirmed new in Korea and registered here with descriptions. These fungi are Auriporia aurulenta, Ceriporiopsis gilvescens, Ceriporiopsis subvermispora, Gloeophyllum trabeum, Junghuhnia separabilima, Oligoporus stipticus, Oxyporus similis, Phellinus lavigatus, and Polyporus melanopus.

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Experimental Study on Behavior of High Strength Bolted Friction Joint with Oversized and Slotted Holes (과대구멍과 슬롯구멍을 갖는 고력볼트 마찰이음부의 거동에 관한 실험적 연구)

  • Kim, Yong Hwan;Roh, Won Kyoung;Lee, Seong Hui;Kim, Jin Ho;Choi, Sung Mo
    • Journal of Korean Society of Steel Construction
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    • v.20 no.6
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    • pp.683-690
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    • 2008
  • When steel fabricators erect structural members in field, temporary tightening of fastener should be useful. However, if bolt holes are not aligned by production error or natural condition, additional effort andpain should be provided to align bolt holes. It lead to longer period than times of construction (a primarily day of construction) and more cost than originally cost. This problem will be overcomed by oversize or slotted holes. Early, AISC and Eurocode have included provision for design process such oversize or slotted holes. But, domestic design method is not refered about oversize and slotted holes. Meanwhile, domestic design method and construction environment are variance with Europe and the United States of America. Therefore, a suitable design method for oversize and slotted holes in domestic real condition is needed. In this study, we evaluated behavior of the joints and decided the friction coefficient on oversize and slotted holes of friction joints with high strength bolts.

표면 응력구배시의 잔류응력 측정에 관한 연구

  • 이택순;최병길;전상윤
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.4
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    • pp.761-768
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    • 1990
  • 본 연구에서는 4-점 굽힘시험 장치를 이용하여 구멍의 표면에서 응력구배를 발생시켰을 때 (구멍의 깊이 방향으로는 응력구배가 없음), 구멍을 뚫기전 표면의 응 력구배를 고려하여 산정한 하중상태와 구멍을 뚫은 후 이완되는 잔류응력을 비교하였 다. 또한 잔류응력 측정시 구멍의 진원도에 대하여 실험적으로 연구하였으며, 구멍 직경의 측정오차가 잔류응력 측정에 미치는 영향을 분석하였다. 연구결과 4-점 굽힘 시험시 하중상태는 응력구배를 고려하여 계측되어야 하며, 응력구배장에서의 잔류응력 을 로젯트 게이지 중심에 존재하는 균일응력으로 나타낼 수 있다.

How is the inner contour of objects encoded in visual working memory: evidence from holes (물체 내부 윤곽선의 시각 작업기억 표상: 구멍이 있는 물체를 중심으로)

  • Kim, Sung-Ho
    • Korean Journal of Cognitive Science
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    • v.27 no.3
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    • pp.355-376
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    • 2016
  • We used holes defined by color similarity (Experiment 1) and binocular disparity (Experiment 2) to study how the inner contour of an object (i.e., boundary of a hole in it) is encoded in visual working memory. Many studies in VWM have shown that an object's boundary properties can be integrated with its surface properties via their shared spatial location, yielding an object-based encoding benefit. However, encoding of the hole contours has rarely been tested. We presented objects (squares or circles) containing a bar under a change detection paradigm, and relevant features to be remembered were the color of objects and the orientation of bars (or holes). If the contour of a hole belongs to the surrounding object rather than to the hole itself, the object-based feature binding hypothesis predicts that the shape of it can be integrated with color of an outer object, via their shared spatial location. Thus, in the hole display, change detection performance was expected to better than in the conjunction display where orientation and color features to be remembered were assigned to different parts of a conjunction object, and comparable to that in a single bar display where both orientation and color were assigned into a single bar. However, the results revealed that performance in the hole display did not differ from that in the conjunction display. This suggests that the shape of holes is not automatically encoded together with the surface properties of the outer object via object-based feature binding, but encoded independently from the surrounding object.

Spinal Nerve Position and Morphometric Analysis with Silicon Molds in the Cadaveric Lumbar Intervertebral Foramen (허리의 척수신경위치와 실리콘을 이용한 척추사이구멍에 대한 형태학적 분석)

  • Kwon, Soonwook
    • Anatomy & Biological Anthropology
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    • v.31 no.4
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    • pp.151-158
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    • 2018
  • The intervertebral foramen is formed by two adjacent vertebrae and an intervertebral disc. Previous studies examining the foramen have been performed using various methods. The author obtained characteristics of the intervertebral foramen based on silicon mold. The author used 18 cadavers and dissected the lumbar intervertebral foramen. First, positional levels of the spinal nerve in the intervertebral foramen were measured. Second, after being removed all tissues covering the intervertebral, bony foramen was filled with melted silicon to mold the cross section. Subsequently, the solidified silicon mold was removed and stamped on a paper. The paper was scanned and analyzed area, perimeter, height and width of the intervertebral foramen on a computer. Area (average, $9.43mm^2$) and perimeter (average, 48.02 mm) did not show any statistical significant pattern for any lumbar vertebral levels. However, the height and width significantly differed at the fifth lumbar vertebra, which had the shortest height (the fifth, 13.00 mm; average, 15.78 mm) and longest width (the fifth, 8.61 mm; average, 7.87 mm), although there were similar patterns in case of area and perimeter of the first to fourth lumbar vertebra. Height had a decrease tendency while width had an increase tendency both from the second to fifth lumbar vertebra. Spinal nerves went through near the intervertebral disc level from the first to fourth lumbar vertebra, although they passed below the disc at the fifth level. This study provides a different view of methodology for the 3-dimensional aspect for the intervertebral foramen. Results of this study may indicate that height and width of the intervertebral foramen changed along all lumbar vertebral levels; nevertheless, area and perimeter of the intervertebral foramen remained constant.

Surface-mediated interference in the radiation from a sub-wavelength-sized aperture in a metal plane (파장보다 작은 금속 구멍의 회절에서 나타나는 표면 효과)

  • ;;A.Chavez-Pirson
    • Proceedings of the Optical Society of Korea Conference
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    • pp.94-95
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    • 2000
  • 파장보다 작은 구멍을 통한 빛의 회절을 다루는 문제는, 최근 근접장 광학의 발달과 더불어서 많은 연구가 되고 있다. 이러한 작은 구멍은 근접장 주사 광학 현미경(NSOM)에서의 탐침(probe)으로 사용되므로, 여기에서 일어나는 빛과 탐침의 상호작용을 잘 이해하는 것이 중요하다.$^{(1)}$ 본 연구에서는 작은 구멍 주변에 선형 스크래치가 있을 때, 구멍을 통한 빛의 회절 분포를 먼 장(far field) 영역에서 관측하였다. 먼 장 분포를 분석해 본 결과, 구멍 주변의 선형 스크래치에 의한 효과가 나타나는 것을 볼 수 있었다. 이것은 구멍 주변에서 발생한 표면파가 금속 표면을 따라가면서, 주변의 스크래치와 상호 작용한 결과로 보인다. (중략)

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