• 제목/요약/키워드: wedges

검색결과 139건 처리시간 0.029초

자가 확장형 전방십자인대 고정장치의 고정 특성에 대한 연구 (A Study on the Fixation Characteristics of a Self-expansion Type ACL Fixation Device)

  • 김종대;김홍건
    • 한국생산제조학회지
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    • 제18권3호
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    • pp.321-327
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    • 2009
  • This paper studied the influences of the main design parameter-the expansion angle and the material properties of the self-expansion anterior cruciate ligament fixation device on the contact condition with the bone and the initial stability of the device. Using finite element analysis, the stress distributions of the ring part of the device and the wall of the bone tunnel were calculated. And the micro-migration of the device by the pull-out force was calculated. From the analysis results, it was found that when designing the self-expansion type anterior cruciate ligament fixation device, it is desirable to use the material having higher Young's modulus and to design the fixation device that all wedges uniformly maintain contact with bone to obtain initial stability after operation.

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개방형 슬롯 구조를 갖는 외전형 영구자석 동기발전기의 코깅 토크 저감을 위한 슬롯 ��지 형상 설계 (Design of Slot Wedge Shape for Reducing Cogging Torque in Outer Rotor Type Permanent Magnet Synchronous Generator with Open Slot Structure)

  • 김봉주;박수강;문재원;권병일
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.936-938
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    • 2011
  • This paper suggests the slot wedge shape for reducing the cogging torque of a gearless type direct-drive permanent magnet synchronous generator with open slot shape. To achieve this, we are designed the appropriate specifications of the permanent magnet synchronous generator by selected the appropriate material of slot wedge and various slot wedge shapes. The PMSG models were analyzed by finite element method. Finally, we have suggested appropriate material of slot wedges and its shape which has benefit to further reducing cogging torque and preventing decreasing of the generating power.

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다중 wedge 및 방음벽에 의한 음파회절 (Sound diffraction by multiple wedges and noise barriers)

  • 김현실;김재승;강현주;김봉기;김상렬
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 2004년도 춘계학술발표대회 논문집 제23권 1호
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    • pp.217-220
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    • 2004
  • 본 논문에서는 다중 wedge와 방음벽에 의한 음파의 회절을 예측하는 공식을 다루었으며 BEM이나 다른 측정결과와 비교하여 정확성을 확인하였다. 여러 가지 경우의 회절경로가 있을 때 가장 적은 수의 회절경로를 따라 전파하는 음파가 가장 중요한 성분이며 회절수가 커질수록 크기는 줄어든다.

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다중 wedge 및 방음벽에 의한 음파회절 II (Sound diffraction by multiple wedges and noise barriers, Part II)

  • 김현실;김재승;강현주;김봉기;김상렬
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 2004년도 추계학술발표대회논문집 제23권 2호
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    • pp.317-320
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    • 2004
  • 본 논문에서는 2004 년도 춘계학회에 발표한 다중 wedge와 방음벽에 의한 음파의 회절 계산방법[1]을 여러가지 형태의 방음벽에 적용하였으며 BEM과 비교하여 정확성을 확인하였다. 상단 일부가 꺾인 방음벽에 대해 꺾는 각도, 길이변화에 따른 삽입손실을 계산하였으며 여러가지 높이의 수음점에 대해 회절을 계산하였다.

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새로운 step wedge의 Bootstrap법에 의한 X선 sensitometry (X-ray Sensitometry by Bootstrap Method Using New Step Wedge)

  • 안봉선;허준
    • 대한방사선기술학회지:방사선기술과학
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    • 제14권1호
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    • pp.45-48
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    • 1991
  • Recently developed new step wedge has a small size as $10{\times}10\;cm^2$. It can use central beam, and is affected little by scattered rays emmitted from the neighboring step wedges. It's characteristics are same as the intensity scale method, and are excellent compared with conventional boot strap methods. Moreover, the method using new step wedge is simple in operation, and the characteristics are excellent. Now, the above method using new step wedge can supercede the distance method.

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THIN-FILM-COATED DETECTORS FOR NEUTRON DETECTION

  • McGregor Douglas S.;Gersch Holly K.;Sanders Jeffrey D.;Klann Raymond T.;Lindsay John T.
    • Journal of Radiation Protection and Research
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    • 제26권3호
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    • pp.167-175
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    • 2001
  • Semiconductor diode detectors coated with neutron reactive material are presently under investigation for various uses, such as remote sensing of thermal neutrons, fast neutron counting, and thermal neutron radiography. Theory indicates that single-coated devices can yield thermal neutron efficiencies from 4% to 11 %, which is supported by experimental evidence. Radiation endurance measurements indicate that the devices function well up to a limiting thermal neutron fluence of $10^{13}/cm^2$, beyond which noticeable degradation occurs. Thermal neutron contrast images of step wedges and simple phantoms, taken with dual in-line pixel devices, show promise for thermal neutron imaging detectors.

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Photon Beam Commissioning for Monte Carlo Dose Calculation

  • Cho, Byung-Chul;Park, Hee-Chul;Hoonsik Bae
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 2002년도 Proceedings
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    • pp.106-108
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    • 2002
  • Recent advances in radiation transport algorithms, computer hardware performance, and parallel computing make the clinical use of Monte Carlo based dose calculations possible. Monte Carlo treatment planning requires accurate beam information as input to generate accurate dose distributions. The procedures to obtain this accurate beam information are called "commissioning", which includes accelerator head modeling. In this study, we would like to investigate how much accurately Monte Carlo based dose calculations can predict the measured beam data in various conditions. The Siemens 6MV photon beam and the BEAM Monte Carlo code were used. The comparisons including the percentage depth doses and off-axis profiles of open fields and wedges, output factors will be presented.

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고속 평면제트와 쐐기에 의한 충돌 순음의 주파수특성 (Frequence Characteristics of Impinging Tones by High-Speed Plane Jets and Wedges)

  • 권영필;장욱;이근희;김욱
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 춘계학술대회논문집
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    • pp.1210-1216
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    • 2001
  • The impinging tones by high-speed plane jets are investigated for the characteristics of edgetone generation based on experimental observations. Experiment has been performed for edgetones with a slit nozzle and a wedge system. The jet in the experiment is varied from low to high subsonic speed to obtain the effect of the speed on the frequency characteristics of impinging tones. The experimental data obtained previously for edgetones and platetones by various nozzles are compared with the present edgetone data for the condition of tone generation, the frequency ranges and the effective source point. It is found that the jet speed has no fundamental influence on the impinging tone characteristics. Regardless of the jet speed, the effective source point is about a quarter wavelength downstream from the edge tip. With increase in jet speed, the influence of the nozzle configuration is decreased and the operating frequencies show good coincidencies by normalized parameters based on the slit thickness.

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유체-구조 상호 간섭을 고려한 쐐기 슬래밍에 대한 실험적 연구 (Experimental Study on Wedge Slamming Considering Fluid-Structure Interaction)

  • 안강수;권순홍
    • 한국해양공학회지
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    • 제31권1호
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    • pp.22-27
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    • 2017
  • This paper presents the results of an experimental study on the wedge slamming impact problem, including the fluid-structure interaction. A free drop test was performed to estimate the hydroelasticity. Three wedges were fabricated of 5 mm thick steel plate. The deadrise angles were $15^{\circ}$, $20^{\circ}$, and $25^{\circ}$. Plate thicknesses of 2 mm and 3 mm were used to determine the effect of the structural rigidity. The drop heights were 25 cm, 50 cm, 75 cm, and 100 cm. The pressure on a rigid part of the wedge and strain of the elastic plate were measured at four different locations. The pressure was compared using the Wagner theory and generalized Wagner theory.

50노트급 활주형선의 저항성능 개선을 위한 부가물 부착에 관한 실험적 연구 (An experimental study on the improvement of resistance performance by appendage for 50 knots class planing hull form)

  • 이귀주;박나라;이은정
    • 수산해양기술연구
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    • 제41권3호
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    • pp.222-226
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    • 2005
  • A series of model tests carried out at the CWC of WJFEL for the purpose of prediction of resistance for the performance and improvement of resistance by attaching appendage for the ship of 50 knots class planing hull. The resistance performance evaluation has been carried out for the bare hull and for the appendage hull with two different depth of vertical type wedges. In the bare model test, trim and sinkage is calculated for the planing hull and the resistance is calculated. For minimizing the resistance, wedge appendage is attached and tested. Analysis and tests shows that for a 12.5mm wedge, resistance is minimum and overall power tallied to 5636ps.