• Title/Summary/Keyword: Curvature Correction

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Computation of Complete Bouguer Anomalies in East Sea (동해 지역의 완전부우게 이상 계산)

  • Kim, Young-Hyun;Yun, Hong-Sik;Lee, Dong-Ha;Huang, He
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2010.04a
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    • pp.165-168
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    • 2010
  • This paper describes the results of complete Bouguer anomalies computed from the Free-air anomalies that derived from Sandwell and DNSC08 mairne gravity models. Complete bouguer corrections consist of three parts: the bouguer correction (Bullard A), the curvature correction (Bullard B) and the terrain correction (Bullard C). These all corrections have been computed over the East Sea on a $1'{\times}1'$ elevation data (topography and bathymetry) derived from ETOPO1 global relief model. In addition, a constant topographic (sea-water) density of $2,670kg/m^3$ ($1,030kg/m^3$) has been used for all correction terms. The distribution of complete bouguer anomalies computed from DNSC08 are -34.390 ~ 267.925 mGal, and those from Sandwell are -32.446 ~ 266.967 mGal in East Sea. The mean and RMSE value of the difference between DNSC08 and Sandwell is $0.036{\pm}2.373$ mGal. The highest value of complete bouguer anomaly are found around the region of $42{\sim}43^{\circ}N$ and $137{\sim}139^{\circ}E$ (has the lowest bathymetry) in both models. Theses values show that the gravity distribution of both models, DNSC08 and Sandwell, are very similar. They indicate that satellite-based marine gravity model can be effectively used to analyze the geophysical, geological and geodetic characteristics in East Sea.

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Correction of Pincer Nail using Autogenous Dermofat Graft (자가 진피지방술을 이용한 집게조갑의 교정)

  • Kim, Hyun-Sung;Kim, Chul-Han;Kang, Sang-Gue;Tark, Min-Seong
    • Archives of Plastic Surgery
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    • v.37 no.3
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    • pp.250-255
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    • 2010
  • Purpose: Pincer nail is a relatively rare deformity characterized by an increase in transverse curvature along the longitudinal axis of the nail. This curvature commonly increases from proximal to distal end of nail, leading to pinching, curling, and distortion of the underlying soft tissue and resulting frequently in severe pain. Numerous surgical procedures have been reported. Preserving the width of the nail in the correction of the pincer nail is very important for functional and aesthetic reasons. We report the results of the correction of the pincer nail using autogenous dermofat graft with a good result. Methods: From May 2006 to September 2008, dermofat graft was performed in 6 patients with pincer nail. Patients were four women and two men, and the average age was 51. The affected digits were the unilateral great toes in four patients and the unilateral thumbs in two patients. Average follow-up period was 13 months. Surgical procedure was removal of nail using an elevator to avoid damage to the nail bed. An incision was created in distal portion of hyponychium. Paronychium was dissected from distal phalanx by periosteal elevator through incision of hyponychium and tunnel was made. Then dermofat grafts harvested from inguinal area were inserted into the tunnel. Finally, a silicone sheet was inserted eponychial fold for prevention of synechia. Objective assessment was evaluated by use of the width index and height index. Results: All patients reported resolution of the pain and soft tissue pinching sensation that they had before the operation. There was good adherence between the nail plate and the underlying nail bed. The nails have regrown and were corrected in a normal and flattened appearance. The width index and height index were improved. Conclusion: The autogenous dermofat graft seems to provide an effective treatment of the pincer nail with preservation of the nail matrix.

Study on the Springback Reduction of Automotive Advanced High Strength Steel Panel (자동차 초고강도 강판 패널의 스프링백 저감에 관한 연구)

  • Kim, B.G.;Lee, I.S.;Keum, Y.T.
    • Transactions of Materials Processing
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    • v.18 no.6
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    • pp.488-493
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    • 2009
  • The very big springback of advanced high strength steel(AHSS) sheets invokes undesired shape defects, which can be generally eliminated by die correction or process parameter control. The springback reduction by controlling the forming process parameters is easy for the application, but limited for the bulky achievement. In this study, the effective die correction method, which obtains the modification of tool shape from the relationship between die design variable and springback, is introduced and is applied to the TWB tool of automotive side rail to show the validity and usefulness. Among the die correction trials repeatedly performed, the first trial is carried out by correcting the tool shape to the opposite direction to the springbacks of several tool sections. Next trials are done by extrapolating the springbacks of among the original tool uncorrected and the tools corrected negative amounts of the springback and by finding tool shapes without springbacks. After the angle of side wall and radius of curvature of horizontal bottom floor are chosen as design variables in the tool design of side rail, the tool shape is corrected 3 times. The accuracy of final shape within the assembly limit of 1mm and the springback reduction of 75.8% compared to the uncorrected tool are achieved.

Comparison of Various Turbulence Models for the Calculation of Turbulent Swirling Jets (난류선회제트 계산에 관한 난류모델 비교 연구)

  • 최동규;최도형;김문언
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.2
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    • pp.440-452
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    • 1990
  • Comprehensive numberical computations have been made for four turbulent swirling jets with and without recirculation to critically evaluate the accuracy and universality of several exising turbulence models as well as of the modified k-.epsilon. model proposed in the present study. A numerical scheme based on the full Navier-Stoke equations ha been developed and used for this purpose. Inlet conditions are given by experiments, whenever possible, to minimize the error due to incorrect initial conditions. The standard k-.epsilon. model performs well for the strongly swirling jets with recirculation while it underpredicts the influence of swirl for weakly swirling jets. Rodi's swirl correction and algebraic stress model do not exhibit universality for the swirling jets. The present modified k-.epsilon. model derived from algebraic stress model accounts for anisotropy and streamline curvature effect on turbulence. This model performs consistently better than others for all cases. It may be because these flows have a strong dependence of stresses on the local strain of the mean flow. The predictions of truculence intensities indicate that this model successfully reflect the curvature effect in swirling jets, i.e. the stabilizing and destabilizing effects of swirl on turbulence transport.

Development of Curved Beam Element with Shear Effect (전단효과를 고려한 곡선보 요소 개발)

  • 이석순;구정서;최진민
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.10
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    • pp.2535-2542
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    • 1993
  • Two-noded curved beam elements, CMLC (field-consistent membrane and linear curvature) and IMLC(field-inconsistent membrane and linear curvature) are developed on the basis of Timoshenko's beam theory and curvilinear coordinate. The curved beam element is developed by the separation of the radial deflection into the bending deflection. In the CMLC element, field-consistent axial strain interpolation is adapted for removing the membrane locking. The CMLC element shows the rapid and stable convergence on the wide range of curved beam radius to thickness. The field-consistent axial strain and the separation of radial deformation produces the most efficient linear element possible.

A Miss Distance Image Analysis Technique Based On Object Contour (윤곽선 기반의 이격거리 영상해석 기법)

  • Park, Won-U;Choi, Ju-Ho;Yoo, Jun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.1 no.1
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    • pp.238-248
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    • 1998
  • This paper presents an image analysis method for mearurement correction using the object contour based analysis, which measure the shape features of the imitation missile object. The image analysis is divided into object's tilting angle analysis and corner points detection. The tilting angle is calculated by edge extracting the region-of-interest image and by Radon transform it. The corner points are obtained by contour tracking of binary image and its curvature data processing and analysis. The ability of this presented method is simulated and evaluated by the results of accuracy testing.

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A Study on the Table Deflection by Stop State and Move Speed at Loaded Load (하중 게재시 정지상태 및 이송속도에 따른 테이블 처짐에 관한 연구)

  • 이지용;김태호;정영덕;박정보;김순경;전언찬
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1117-1122
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    • 2003
  • The paper on table deflection by stop state and move speed at loaded load, and the table deflection measured of static load. It is developed program for Date correction of LSM(Least Square Method). We experimented the method as following. The first a Laser setting and scan Experimental device measured curvature radius, The second A center of measurement object and curvature radius taking of LSC.

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On Effects of Large-Deflected Beam Analysis by Iterative Transfer Matrix Approach

  • Sin, Jung-Ho
    • 한국기계연구소 소보
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    • s.18
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    • pp.131-136
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    • 1988
  • A small-deflected beam can be easily solved by assuming a linear system. But a large-deflected beam can not be solved by superposition of the displacements, because the system is nonlinear. The solutions for the large-deflection problems can not be obtained directly from elementary beam theory for linearized systems since the basic assumptions are no longer valid. Specifically, elementary theory neglects the square of the first derivative in the beam curvature formula and provides no correction for the shortening of the moment-arm cause by transverse deflection. These two effects must be considered to analyze the large deflection. Through the correction of deflected geometry and internal axial force, the proposed new approach is developed from the linearized beam theory. The solutions from the proposed approach are compared with exact solutions.

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Angular Momentum Effect of Electron Scattering with Reduced Angular Momentum Expansion (축약 각운동량 전개(Reduced Angular Momentum Expansion) 방법으로 해석한 전자 산란의 각 운동량 효과)

  • Kang, J.H.
    • Journal of the Korean Magnetics Society
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    • v.18 no.1
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    • pp.36-38
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    • 2008
  • We calculate the electron scattering amplitude with reduced angular momentum expansion(RAME) and compare it with the plane wave approximation. By using WKB approximation it is shown that the curvature correction factor given by RAME is originated from the source wave centrifugal potential energy. The factor also can be understood as an effective wave number correction factor in plane wave approximation. Angular momentum and its relationship with scattering amplitude is explicitly shown.

Marlex mesh Support for the Correction of Severe Pectus Excavatum

  • Lee, Doo-Yun;Kim, Hong-Suk;Cho, Bum-Koo
    • Journal of Chest Surgery
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    • v.23 no.3
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    • pp.609-615
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    • 1990
  • Pectus excavatum is a congenital anomaly of the anterior chest wall with a sharp concave curvature of the body of the sternum, from above downward and from side to side, especially just before the junction of the glandioloxiphoid. There are two major operative procedures -"Ravitch" or "Wada" operation- for the correction of pectus excavatum. We used the modified Ravitch operation which consists of mobilization of the sternum, transverse osteotomy, and parasternal resection of the costal cartilages followed by placement of Marlex mesh using methyl methacrylate behind the sternum and suturing the edge of the Marlex mesh to the peripheral stump of the resected ribs. This was performed in a patient with severe pectus excavatum with good results at the Department of Thoracic and Cardiovascular Surgery Yonsei University College of Medicine in Seoul, Korea on January 12, 1989.anuary 12, 1989.

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