• 제목/요약/키워드: Two-wedge

검색결과 328건 처리시간 0.022초

보강사면(補强斜面)에 대한 Centrifuge Test와 Two-part Wedge 해석(解析)의 비교평가(比較評價) (Comparison and Evaluation of Two-part Wedge Analysis for Reinforced Slopes with Centrifuge Test)

  • 서인식;이친;김병탁
    • 한국산업융합학회 논문집
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    • 제2권2호
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    • pp.35-39
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    • 1999
  • Results of two-part wedge analysis and centrifuge test executed by Zornberg et al. were compared for geotextile-reinforced slope stability. For two-part wedge analysis results of two cases, a frictional case considering internal friction of soil as interwedge friction and a nonfrictional case not considering, were also compared and evaluated. The analysis was based on limit equilibrium and two-part wedge was divided into slices as many as the number of geotextiles to obtain a maximum tension distribution mobilized in reinforcements. A significant observation was that the distribution was a triangular shape with maximum tension of geotextile at a transit point of interwedge. The number of geotextiles and failure surface of frictional case were reasonable and more comparable to results of the centrifuge tests than those of nonfrictional case. Therefore it can be said that two-part wedge analysis is recommendable for design analysis of reinforced slopes if an interwedge angle is regarded to be an angle of internal friction in soil.

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쇄기형 유전체의 물리광학 근사해를 교정하는 두 수정 방법의 비교 (Comparison of two correction schemes to the physical of tics solution in case of dielectric wedge)

  • 김세윤;나정웅;신상영
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1984년도 하계학술회의논문집
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    • pp.287-291
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    • 1984
  • The electromagnetic wave scattered by an arbitrary-angled dielectric wedge is constructed by physical optics solution and its corrected field. Two models of correction source are obtained; one is multipole line source at tip of wedge and the other is correction electric and magnetic currents distributed along the interfaces of dielectric wedge. Calculated far-field patterns are presented and compared each other.

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염수쐐기의 비정상적 거동특성 (The Behavior of Unsteady Saline Wedge)

  • 이문옥
    • 한국해안해양공학회지
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    • 제3권2호
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    • pp.72-80
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    • 1991
  • 조석이 작용하는 흐름장에 있어서 염수쐐기의 거동특성을 파악하여, 실제의 하구에서 생성되는 비정상적염수쐐기의 형상과 그 길이를 정확하게 예측할 수 있는 수치모델의 구축을 목적으로, 수리실험 및 수치계산을 행하였다. 실험에서는 특히 조시에 따른 염수쐐기의 하층에서의 유속분포의 변화와 선단부의 거동에 주목하였다. 또한 점변일차원이층부정류모델에 의한 염수쐐기 형상의 수치계산을 행하여 실험결과와의 비교에 의해 그 모델의 적용성에 대하여 검토하였다.

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Wedge Prism을 이용한 FHD급 연성 내시경 광학계 설계 (FHD Flexible Endoscopy Design Using Wedge Prism)

  • 박성우;정미숙
    • 한국광학회지
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    • 제33권6호
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    • pp.295-302
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    • 2022
  • FHD급 고해상도 연성 내시경을 설계하기 위한 wedge prism 적용 방법을 연구하였다. 기존의 연성 내시경 광학계의 경우, 넓은 피사계 심도 범위에서 동일한 결상 성능을 얻기 위해 F 넘버를 크게 가져가거나 액체 렌즈를 적용하였다. 하지만 이는 추가적인 light guide와 기구물을 필요로 하여 광학계의 직경이 커진다는 문제점이 있다. 이를 해결하기 위해, 연성 내시경 광학계에 2매의 wedge prism을 적용하여 각 물체거리별로 상거리를 조절하였다. 먼저 설계한 내시경 광학계에 2매의 wedge prism을 대칭으로 배치하고, 각 물체거리별로 목표 결상 성능을 만족하는 상거리 값을 도출하였다. 그 다음, 상거리를 조절하기 위한 wedge prism 디센터 값을 도출하였다. 이 두 가지 데이터를 조합하여, 각 물체거리에서 목표 결상 성능을 만족하는 wedge prism 디센터 값을 다중구성으로 적용하였다. Wedge prism을 적용한 최적 설계 결과, 100 mm-7 mm의 전체 피사계 심도 범위에서, 분해능 178 cycles/mm에 대한 변조전달함수 20% 이상의 목표 결상 성능을 만족하였다.

Dose Volume Histogram Analysis for Comparison of Usability of Linear Accelerator Flattening Filter

  • Ji, Yun-Sang;Dong, Kyung-Rae;Ryu, Jae-Kwang;Choi, Ji-Won;Kim, Mi-Hyun
    • 방사선산업학회지
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    • 제12권4호
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    • pp.297-302
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    • 2018
  • The wedge filter has two movements, fixed and dynamic. In this study, the depth dose distribution was analyzed to determine the stability of the dose distribution and dose volume histograms obtained by evaluating the usability of the critical normal tissue dose around the tumor dose. The depth dose was analyzed from the dose distribution from a Linac (6 MV and 10 MV irradiation field of energy $20{\times}20cm^2$, wedge filter with a SSD of 100 cm and $15^{\circ}$, $30^{\circ}$, $45^{\circ}$ Y1-in (Left -7 cm), Y2-out(Right +7 cm). To analyze the fluctuations of the depth dose, a fixed wedge and dynamic wedge toe portion was examined according to the energy and angle because the size of the fluctuations was included in the error bound and did not show significant differences. The neck, breast, and pelvic dosimetry in tumor tissue are measured more commonly with a dynamic wedge than a fixed wedge presumably due to the error range. On the other hand, dosimetry of the surrounding normal tissue is more common using a fixed wedge than with a dynamic wedge.

2차원 및 축대칭 운동체 주위의 초공동 현상에 대한 수치해석 (NUMERICAL ANALYSIS OF SUPER-CAVITATING FLOW AROUND TWO-DIMENSIONAL AND AXISYMMETRIC BODIES)

  • 박선호;이신형
    • 한국전산유체공학회지
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    • 제16권1호
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    • pp.14-21
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    • 2011
  • Super-cavitating flows around under-water bodies are being studied for drag reduction and dramatic speed increase. In this paper, high speed super-cavitating flow around a two-dimensional symmetric wedge-shaped body were studied using an unsteady Reynolds-averaged Navier-Stokes equations solver based on a cell-centered finite volume method. To verify the computational method, flow over a hemispherical head-form body was simulated and validated against existing experimental data. Various computational conditions, such as different wedge angles and caviation numbers, were considered for the super-cavitating flow around the wedge-shaped body. Super-cavity begins to form in the low pressure region and propagates along the wedge body. The computed cavity lengths and velocities on the cavity boundary with varying cavitation number were validated by comparing with analytic solution.

접착 LAP JOINT 해석을 위한 두 상태 M-적분의 응용 (APPLICATIONS OF TWO-STATE M-INTEGRAL FOR ANALYSIS OF ADHESIVE LAP JOINTS)

  • 임세영;이용우
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1997년도 봄 학술발표회 논문집
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    • pp.35-42
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    • 1997
  • The two-state or mutual M-integral which is derived from tile M-integral and is applicable for two elastic states, is applied for computing all intensity of a singular near-tip field around the vertex of a class of wedge, encountered in adhesive lap joints under mechanical loading. Numerically we verify that a simple auxiliary field associated with every eigenfunction for the composite wedge under consideration exists in the form of the conjugate solution in the sense of tile M-integral. The auxiliary field is then employed for superposition with the elastic field under consideration, and the associated two-state M-integral is computed via the domain integral technique. This enables us to extract the intensity for a singular field information for a singular elastic boundary layer is extracted form the domain integral representation without resort to singular finite element for the wedge vertex.

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Determination of an Effective Wedge Angle by Combination of Two Arbitrary Universal Wedge Fields in Radiation Therapy of Cancer Patients with Megavoltage Photon Beams

  • Shamsi, Azin;Birgani, Mohammad Javad Tahmasebi;Behrooz, Mohammad Ali;Arvandi, Sholeh;Fatahiasl, Jafar;Maskny, Reza;Abdalvand, Neda
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권1호
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    • pp.197-200
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    • 2016
  • Background: Wedge filters are commonly used in radiation oncology for eliminating hot spots and creating a uniform dose distribution in optimizing isodose curves in the target volume for clinical aspects. These are some limited standard physical wedges ($15^{\circ}$, $30^{\circ}$, $45^{\circ}$, $60^{\circ}$),or creating an arbitrary wedge angle, like motorized wedge or dynamic wedge,${\ldots}$ The new formulation is presented by the combination of wedge fields for determining an arbitrary effective wedge angles. The isodose curves also are derived for these wedges. Materials and Methods: we performed the dosimetry of Varian Clinac 2100C/D with Scanditronix Wellhofer water blue phantom, CU500E, OmniPro - Accept software and 0.13cc ionization chamber for 6Mv photon beam in depth of 10cm (reference depth) for universal physical wedges ($15^{\circ}$, $30^{\circ}$, $45^{\circ}$, and $60^{\circ}$) and reference field $10.10cm^2$. By combining the isodose curve standard wedge fields with compatible weighting dose for each field, the effective isodose curve is calculated for any wedge angle. Results: The relation between a given effective wedge angle and the weighting of each combining wedge fields was derived. A good agreement was found between the measured and calculated wedge angles and the maximum deviation did not exceed $3^{\circ}$. The difference between the measured and calculated data decreased when the combined wedge angles were closer. The results are in agreement with the motorized single wedge appliance in the literature. Conclusions: This technique showed that the effective wedge angle that is obtained from this method is adequate for clinical applications and the motorized wedge formalism is a special case of this consideration.

신발굽 높이와 Wedge 위치 변화가 하지 근활성도에 미치는 영향 (Effect on the Lower Extremity Muscle Activity According to the Heel Height and Wedge Position)

  • 이현주;김소정;김순종;김혜지;박보람;박소영;유정화;태기식
    • 재활복지공학회논문지
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    • 제8권4호
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    • pp.291-297
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    • 2014
  • 본 연구는 30명의 여성에게 내 외측 wedge 삽입과 함께 flated heel 또는 5cm heel을 착용하도록 한 후, 넙다리네갈래근 중 안쪽빗넓은근(VMO)과 가쪽넓은근(VL)의 근활성도를 측정하여 비교하였다. 연구 결과 내외측 wedge 모두에서 flated heel 군에서는 가쪽넓은근이, 5 cm heel 군에서는 안쪽빗넓은근의 근활성도가 높게 나타났으며 가쪽넓은근에 대한 안쪽빗넓은근의 근활성도비(% VMO/VL) 또한 5cm heel 군에서 유의하게 높게 나타났다. 이는 안쪽빗넓은근과 가쪽넓은근의 근활성도에 영향을 미치는 외적 변수가 wedge의 내외측 위치보다는 힐의 높이에 의함을 알 수 있었다. 차후 무릎통증이나 무릎 불안정성으로 인한 하지 재활훈련 또는 하지보조기 제작 시에 하지 근육의 선택적 활성화를 유도하기 위한 변수로써 heel 높이를 고려할 수 있을 것이다.

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