• Title/Summary/Keyword: Two-wedge

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

  • Seo, In-Shik;Lee, Chin;Kim, Byung-Tak
    • Journal of the Korean Society of Industry Convergence
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    • v.2 no.2
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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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Comparison of two correction schemes to the physical of tics solution in case of dielectric wedge (쇄기형 유전체의 물리광학 근사해를 교정하는 두 수정 방법의 비교)

  • Kim, Se-Yun;Na, Jeong-Ung;Sin, Sang-Yeong
    • Proceedings of the KIEE Conference
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    • 1984.07a
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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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The Behavior of Unsteady Saline Wedge (염수쐐기의 비정상적 거동특성)

  • 이문옥
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.3 no.2
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    • pp.72-80
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    • 1991
  • This study presents the behavior of unsteady saline wedge in which it is examined velocity profile variations at the lower layer (inner wedge) and wedge tip responses to a tidal action in a rectangular open channel. Unsteady saline wedge has just tidal excursions corresponding to tidal amplitudes at the river mouth, although two wedge tips in flood and ebb tide remarkably have different shapes. Maximum velocities at the lower layer appear immediately from high water to low water level (or low to high water). Numerical computation results obtained by only just interfacial friction factor at the steady state show satisfactory agreements with experimental data. However, the numerical model on one-demensional two-layer flor still has some problems to date.

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

  • Park, Sung-Woo;Jung, Mee-Suk
    • Korean Journal of Optics and Photonics
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    • v.33 no.6
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    • pp.295-302
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    • 2022
  • In this paper, a wedge prism application method was studied to design a full-high-definition (FHD)-class high-resolution flexible endoscope. In the case of the conventional flexible endoscope optical system, the F number is made large or a liquid lens is applied to obtain the same imaging performance in a wide depth of field. However, there is a problem in that the diameter of the optical system increases because an additional light guide and equipment are required. To solve this problem, two wedge prisms were applied to the flexible endoscope optical system to adjust the image distance for each object distance. First, two wedge prisms were symmetrically placed on the designed endoscopic optical system. An image distance satisfying the target imaging performance according to each objective distance was derived. Next, the wedge prism decenter value for controlling the image distance was derived. By combining these two data, a wedge prism decenter value that satisfied the target imaging performance at each object distance was applied in multi configurations. As a result of the optimal design applied with the wedge prism, a target imaging performance of more than 20% of the modulation transfer function for a resolution of 178 cycles/mm was satisfied in the entire depth of field of 100 mm-7 mm.

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
    • Journal of Radiation Industry
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    • v.12 no.4
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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.

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

  • Park, Sun-Ho;Rhee, Shin-Hyung
    • Journal of computational fluids engineering
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    • v.16 no.1
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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.

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

  • 임세영;이용우
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1997.04a
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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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    • v.17 no.1
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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.

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

  • Lee, H.J.;Kima, S.J.;Kimb, S.J.;Kim, H.J.;Park, B.R.;Park, S.Y.;Yu, J.H.;Tae, K.S.
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.8 no.4
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    • pp.291-297
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    • 2014
  • The purpose of this study was to investigate the change of the electromyographic activity in vastus medialis oblique (VMO) and vastus lateralis (VL), also vastus medialis oblique/vastus lateralis ratios after wearing wedged flated or 5cm heel shoes. The subjects were 30 healthy women who randomly assigned to two group, divided by flated or 5cm heel group. They were asked to perform squat exercise in two postures using medial and lateral wedged shoes. In two groups, EMG activity of VMO and VL was significant difference between the flated heel and 5cm heel (p<.01). This study showed that 5cm heel could selectively more active VMO than flated heel. It should be considered the heel height as the parameter when the patient with lower extremity problem undergo rehabilitation exercise or design of orthoses for the selective muscle activity of knee pain or knee instability.

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