• 제목/요약/키워드: OT-IT

검색결과 271건 처리시간 0.022초

국부충격하중을 받는 원관의 삭성변형에 관한 고찰 (Study on the plastic deformation of a cylinder subjected to localized impulsive pressure)

  • 김천욱;주영우
    • 대한기계학회논문집
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    • 제5권2호
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    • pp.131-138
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    • 1981
  • The effect of axial stress on the plastic deformation of rigid-perfectly plastic cylindrical tube under the impulsive band pressure is investigated. It is assumed that the tube is constructed with the material of Tresca's yield criterion. A closed from sloution is obtained for a rectangular pulse shape of uniform band pressure by using the circumscribed yield surface. The analysis shows that the effect ot exial stress is negligible when the dimensionless axial stress(n$\sub$x/= N$\sub$x/.delta.$\sub$y/H) is less than 0.2 or the dimensionless whdth of band pressure(.xi.=C/.root.RH) is greater than 2, but the effect of axial stress is of considerable importance when the axial stress is greater than 0.3 and the width of band pressure is less than 1.

한국어 형태소 분석기에서 '아/어'로 시작되는 어미의 분석 (The Analysis of Endings Which Begin with 'a/a in Korean Morphological Analyzer)

  • 강승식;김영택
    • 인지과학
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    • 제3권1호
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    • pp.25-39
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    • 1991
  • 한국어 어미 중 '아/어'로 시작되는 어미는 용언의 어간과 결합할 때 '아/어'가 축약되거나 '아/어'의 'ㅇ' 이 탈락되기도 한다.특히'ㅎ'불규칙 용언과 결합할 때는 용언의 어간모음과 화합되어 '-ㅐ-','-ㅒ-'로 바뀌는 경우가 있고,'-하다-'로 끝나는 용언의 어간과 결합하면 '-여-'혹은'-ㅐ-'로 바뀌게 된다.본 논문에서는 한국어 형태소 분석기에서 '아/어'로 시작되는 어미의 변이체를 처리하기 위하여 문법형태소 사전을 어떻게 구성하여야하고, 문법형태소 사전이 주기억 장치에 적제될 때 2진트리를 어떻게 구성할 것인에 대한 방법론을 제시함으로써 '아/어' 로 시작되는 어미의 변이체를 형태소 분석할때 발생하기 쉬운 오류를 방지할수 있도록 한다.

인공신에 의한 백혈구 수의 변화 혈장 및 알부민의 전처치가 이에 미치는 영향 (The Effect of Cuprophane Hemodialyzer Treated with Plasma and Albumin on Leukocyte Count)

  • 장현규;박찬현
    • 대한의용생체공학회:의공학회지
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    • 제8권2호
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    • pp.241-244
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    • 1987
  • It is now well established that transient granulocytopenia is common in patients during the initial phase of hemodialysis with new cuprophane membrane, but not with reused nembrane, or some synthetic membranes. In this study, new cuprophane dialyzer was treated with plasma and albumin, respectively, then, peripheral blood leukocytes were counted at the onset and after 15 minute of hemodialysis. In the plasma-treated group, the percent of leukopenia was less (41.3 %) than control group (71.3 %). In the plasmatreated group, the degree of leukopenia was close to that ot'control grou p. The protective factor, therefore is thought to be present in the plasma other than albumin fraction.

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CSR-H를 적용한 SUEZMAX급 TANKER의 구조해석 결과 및 고찰 (A study on structural analysis for suezmax tanker applied CSR-H)

  • 박성영
    • 대한조선학회 특별논문집
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    • 대한조선학회 2017년도 특별논문집
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    • pp.73-79
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    • 2017
  • IACS enacted Harmonized CSR(CSR-H) to meet the IMO GBS applied from 1 July 2016. CSR-H is clearly complement and integrate than present CSR-BC & CSR-OT. One of the biggest issue in new rule is structural analysis. In CSR-H, structural analysis must carried out entire each cargo area including the aft bulkhead of the aftermost cargo hold and the collision bulkhead. Accordingly, new load and boundary conditions are present, an additional structural reinforcement is required by the structural analysis result for each cargo hold. In this study, we applied CSR-H to existing 158K DWT CLASS CRUDE OIL TANKER in order to compare and analyze the hull changes. It is useful for the application of the CSR-H to the similar vessel and helpful in finding the optimized structural design.

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KSTAR 중성빔 입사(NBI) 장치 배기계통 설계 (Design of the vacuum pumping system for the KSTAR NBI device)

  • 오병훈;인상렬;조용섭;김계령;최병호
    • 한국진공학회지
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    • 제8권4B호
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    • pp.548-555
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    • 1999
  • The NBI (Neutral BGeam Injection) System for the Korea Superconducting Tokamak Advanced Research (KSTAR) is composed of ion sources, neutralizers, bending magnets, ion dumps, and calorimeter. The vacuum chamber, in which all of the beam line components are enclosed, is composed of differential pumping system for the effective transfer of the neutral beams. The needed pumping speeds of each of the divided vacuum chamber and the optimized gas flow rate ot the neutralizer were calculated with the help of the particle balance equations. The minimum gas flow rate to the ion sources for producing needed beam current (120kV, 65A, 78MW), the pressure distributions in the vacuum chamber for minimizing re-ionization loss, and the beam loss rate on the beam line components were used as the input in the calculation. Also the scenario for short pulse operation was determined by analysing the time dependent equations. It showed that beam extraction during less than 0.5 sec could be made only with TMP.

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박뿔게 (십각목, 단미류, 물맞이게과)의 제 1 조에아 유생 (The first zoeal stage of Hyastenus elongatus (Ortmann, 1893) (Decapoda, Brachyura, Majidae))

  • 고현숙
    • Animal Systematics, Evolution and Diversity
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    • 제13권1호
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    • pp.1-8
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    • 1997
  • 실험실에서 포란한 박뿔게로부터 제 1조에아 유생을 얻었다. 제 1조에아 유생기의 형태적 특징을 상세히 기재 및 도시하고 이미 보고된 뿔게아과 다른 종의 조에아 유생들과 그 형태적 특징을 비교하였다. 박뿔게와 뿔게의 제 1조에아 유생은 형태적으로 유사하나 갑각후측연부와 구기부속지의 강모수와 등가시의 길이가 서로 다르다. 특히 구기부속지중 제 1소악의 내지 강모수가 다르기 때문에 뿔게유생에 대한 상세한 재기재를 필요로 한다.

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Single-poly EEPROM의 프로그램 및 소거특성에 관한 연구 (A study on the programming and erasing chracteristics of single-poly EEPROM)

  • 류영철;유종근;이광엽;김영석;박종태
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1998년도 하계종합학술대회논문집
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    • pp.425-428
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    • 1998
  • In this work, single-poly EEPROM has been designed and fabricated by using standard 0.8.mu.m CMOS process. The initial threshold voltage was aobut 0.8V but it increased ot about 6.5V after programming at Vds=11.5V and Vcg=6.5V. After erasing devices at Vs=14.2V, the threshold voltage decreased to about 1.5V. The programming time and erasing trime wree about 6ms. and 100ms. respectively. The erasing time can be reduced by applying a series of shorter erase pulse s instead of a long single erase pulse.

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The characteristics of MIS BST thin film capacitor

  • Park, Chi-Sun;Kim, In-Ki
    • 한국결정성장학회지
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    • 제11권1호
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    • pp.38-42
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    • 2001
  • Electric and dielectric(Ba,Sr)$TiO_3$[BST] thin films for emtal-Insulator-Semiconductor(MIS) capacitors have been studied. BST thin films wre deposted on p-Si(100) substrates bythe RF magnetron sputtering with tempratue range of 500~$600^{\circ}C$. The dielectric properties of MIS capacitors consisting of Al/BST/$SiO_2$/Si sandwich structure were evaluated ot redcue the leakage current density. The charge state densities of the MIS capacitors were determined by high frequency (1 MHz) C-V measurement. In order to reduce the leakage current in MIS capacitor, high quality $SiO_2$ layer was deposited on bare p-Si substrate. Depending on the oxygen pressure and substrate temperature both positive and negative polarities of effective oxide charge in the MIS capacitors were evaluated. It is considered that the density of electronic states, generated at the BST/$SiO_2$/p-Si interface due to the asymmetric structure within BST/$SiO_2$/Si structure, and the oxygen vacancy content has influence on the behavior of oxide charge.

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저발열형 시멘트 개발에 관한 연구 (Study on Low Heat Cements)

  • 최재웅;하재담;김동석;김기수;최롱
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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    • pp.46-51
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    • 1999
  • Mass concrete structures have many critical points in service. The cracks caused by the heat of hydration is the most serious problem, so that many method ot control cracks(precooling, postcooling, etc) have been applied to construction. But cooling methods take high cost and many installation and limits of field. Therefore it is useful to use the low heat hydration cements for low cost. This paper describes the characteristics of a low heat cement mixing the ternary components of cement(portland cement, blast furnace slag, fly ash) recently developed for mass concrete, belite cement, low heat slag cement(belite base) and fly ash cement (belite base). The objective of this paper is to study on low heat cement about initial compressive strength and hydration heat.

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정전기 방전에 의한 전자 간섭빈도의 통계적 추정 (A statistical estimation of electromagnetic detection rate caused by electrostatic discharge)

  • 강인호;이창복;정옥현
    • 전자공학회논문지D
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    • 제34D권10호
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    • pp.7-13
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    • 1997
  • A modern electronic system located at a certain distance form the discharge may respond with unexpected sensitivity ot that phenomenon, even if the phenomenon is so slight as to have been ignored in the port. It has been found that electromagnetic wave energy is emitted as a results of this electrostatic discharge between metallic objects. In order to theoretically examine the peculiar phenomenon, we propose an analytical approach to model the indirect ESD effect. A soruce model is given here using the spark resistence presented by rompe-weizel. A model experiment for indirect eSD is also conducted to express ESD detection rate by the statistical estimation. We verify that the statistical estimations agree the theoretical curve resulted from the rompe-weisel resistence.

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