• Title/Summary/Keyword: combination region

검색결과 703건 처리시간 0.031초

레이저 용접 테일러드 블랭크를 이용한 사이드 패널 성형 (Stamping of Side Panel Using the Laser Welded Tailored Blank)

  • 권재욱;명노훈;백승엽;인정제;이경돈
    • 소성∙가공
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    • 제8권1호
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    • pp.7-13
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    • 1999
  • In this study, side panels were developed using the laser-welded tailored blank (T.B.) of both the same thickness and different thickness. At first, the formability of the same thickness T.B. was investigated to compare with one of the non-welded panel with respect to weldline movement and strain distribution in blank during the stamping process. Based on these results, we determined the weld line positions and the die step for T.B. forming of the blanks composed of different thickness combination. Then we made some stamping tryouts with selected types of blanks to investigate the formability of T.B. of the different thickness. During the tryouts, wrinkles were found in the a-pillar lower region which is under the deformation mode of the shrink flange. In the b-pillar region, fractures were also found. These defects have been reduced and corrected by controlling the blank design, the die faces and process parameters.

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AN OVERLAPPING SCHWARZ METHOD FOR SINGULARLY PERTURBED THIRD ORDER CONVECTION-DIFFUSION TYPE

  • ROJA, J. CHRISTY;TAMILSELVAN, A.
    • Journal of applied mathematics & informatics
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    • 제36권1_2호
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    • pp.135-154
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    • 2018
  • In this paper, an almost second order overlapping Schwarz method for singularly perturbed third order convection-diffusion type problem is constructed. The method splits the original domain into two overlapping subdomains. A hybrid difference scheme is proposed in which on the boundary layer region we use the combination of classical finite difference scheme and central finite difference scheme on a uniform mesh while on the non-layer region we use the midpoint difference scheme on a uniform mesh. It is shown that the numerical approximations which converge in the maximum norm to the exact solution. We proved that, when appropriate subdomains are used, the method produces convergence of second order. Furthermore, it is shown that, two iterations are sufficient to achieve the expected accuracy. Numerical examples are presented to support the theoretical results. The main advantages of this method used with the proposed scheme are it reduce iteration counts very much and easily identifies in which iteration the Schwarz iterate terminates.

버터플라이 밸브 하류 유동의 안정화에 관한 연구 (An Experimental Study on the Flow Stabilization in the Downstream Region of a Butterfly-Type Valve)

  • 박상원;이상우
    • 대한기계학회논문집B
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    • 제24권11호
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    • pp.1417-1427
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    • 2000
  • A flow stabilizer, which is made of a honeycomb and three different mesh screens, is located downstream of a butterfly-type valve, for the reduction of flow disturbances behind the valve. Mean flow and turbulence measurements as well as flow visualizations are conducted in the downstream region of the deepens the non-uniformity of the streamwise velocity component and turbulence. The mesh screens considerably reduce the turbulence and enhance the uniformity of mean velocities. The combination of the honeycomb and the three mesh screens results in an efficient reduction in the flow disturbances. In addition, the flow stabilizer proves to have a good performance in the suppression of turbulence at a short distance.

Zr-기 벌크 금속 유리의 마찰 접합 공정 개발 (Development of Friction Welding Process of Zr-based Bulk Metallic Glasses)

  • 신형섭;정영진;김기현
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.337-341
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    • 2004
  • Bulk metallic glasses(BMG) with good mechanical properties have problems that engineering application fields have been limited because of limitation of the alloy size. In order to solving this problem, the friction welding of BMG has been tried using the superplastic-like deformation behavior under the supercooled liquid region. The apparatus for friction welding test was designed and constructed using pneumatic cylinder and gripper based on a conventional lathe. Friction welding have been tried to combination of same BMG alloy and crystalline alloys. The results of welding test were evaluated by X-ray diffraction, measurement of hardness and mechanical properties test. In order to obtain the optimized welding test conditions the temperature of friction interface was measured using Infrared thermal imager.

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대퇴골 전자간부 해면골의 미세구조적 특성과 생역학적 특성에 관한 연구 (A study on the micro-structural and biomechanical properties of trabecular bone in intertrochanteric region)

  • 백명현;원예연;최문권;김광균;김한성
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.923-926
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    • 2005
  • To investigate the relationship between BMD, micro-structural and mechanical properties in intertrochanteric trabecular bone, the PIXI-mus2 system, micro-CT and FE model were used. The purpose of this study were (1) to apply high-resolution imaging techniques (micro-CT imaging) in combination with new computer modeling techniques (FEA) to quantify 3D microstructural and biomechanical properties of trabecular bone in the intertrochanteric region, and (2) determine if the prediction of bone elastic constant can be improved with structural index.

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A Case of Calvarial Hemangioma in Cranioplasty Site

  • Kang, Dong-Wan;Choi, Chang-Hwa
    • Journal of Korean Neurosurgical Society
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    • 제46권5호
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    • pp.484-487
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    • 2009
  • It is not uncommon for hemangiomas to occur in the calvarium, accounting for about 10% of the benign skull tumors. A 46-year-old man was presented with a palpable scalp mass on the left parietal region. Past medical history indicated that he had undergone cranioplasty 25 years prior due to a depressed skull fracture suffered from a traffic accident. Magnetic resonance imaging revealed mixed signal intensity mass on T1 -and T2- weighted images pushing a linear signal void lesion outward in the left parietal region. After total surgical removal along with cranioplasty, he was discharged without neurological deficits. Histological examination of the surgical specimen revealed a cavernous hemangioma. A skull hemangioma occurring at the site of a cranioplasty has not yet been reported. Therefore, authors report this case in combination with a pertinent literature review.

고받음각의 NACA23012익형에서 synthetic jet을 이용한 박리 제어 연구 (SEPARATION CONTROL USING SYNTHETIC JET ON NACA23012 AT HIGH ANGLE OF ATTACK)

  • 김상훈;김종임;김규홍
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2005년도 추계 학술대회논문집
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    • pp.125-129
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    • 2005
  • Flow control has been performed using synthetic jet on NACA23012. In order to improve aerodynamic performance, synthetic jet is located near separation paint on airfoil with leading edge droop and plain flap. The flow control using synthetic jet shows that stall characteristics and control surface performance can be improved through resizing separation vortices. Stall is delayed and stall characteristics are improved when synthetic jet is applied from separation region of leading edge droop. Control surface effectiveness is increased and lift is increased when synthetic jet applied at the flap leading edge region. The results show that aerodynamic characteristics can be improved through leading edge droop with synthetic jet at near separation and plain flap with synthetic jet at the flap leading edge. The combination of synthetic jet and simple high lift device is as good as fowler flap system.

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날개다랑어(Thunnus alalunga) 치어의 국내 출현 (Occurrence of a Thunnus alalunga Juvenile from Korea)

  • 유준택;김장근;김진구;유정화
    • 한국수산과학회지
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    • 제45권2호
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    • pp.180-182
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    • 2012
  • A single juvenile specimen of $Thunnus$ $alalunga$ (8.4 mm in standard length) of the Scombridae was collected from the southeast sea of Jeju Island ($127.7^{\circ}E$, $33.0^{\circ}N$) on August 18, 2011. It was identified as $T.$ $alalunga$ based on the following combination of morphological characters: snout elongated; melanophores focused on the dorsal spiny region, but no melanophores on the dorsal soft fin base, anal fin base or caudal region.

Ultrahuge Light Intensity in the Gap Region of a Bowtie Nanoantenna Coupled to a Low-mode-volume Photonic-crystal Nanocavity

  • Ebadi, Nassibeh;Yadipour, Reza;Baghban, Hamed
    • Current Optics and Photonics
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    • 제2권1호
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    • pp.85-89
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    • 2018
  • This paper presents a new, efficient hybrid photonic-plasmonic structure. The proposed structure efficiently and with very high accuracy combines the resonant mode of a low-mode-volume photonic-crystal nanocavity with a bowtie nanoantenna's plasmonic resonance. The resulting enormous enhancement of light intensity of about $1.1{\times}10^7$ in the gap region of the bowtie nanoantenna, due to the effective optical-resonance combination, is realized by subtle optimization of the nanocavity's optical characteristics. This coupled structure holds great promise for many applications relying on strong confinement and enhancement of optical field in nanoscale volumes, including antennas (communication and information), optical trapping and manipulation, sensors, data storage, nonlinear optics, and lasers.

이종해법의 병용에 관한 연구 (A Study on Combination of Various Numerical Analysis Methods)

  • 임지원;추동욱;한석우
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 학술대회 논문집 전문대학교육위원
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    • pp.99-103
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    • 2000
  • The finite element method (FEM) is suitable for the analysis of a complicated region that includes nonlinear materials, whereas the boundary element method (BEM) is naturally effective for analyzing a very large region with linear characteristics. Therefore, considering the advantages in both methods, a novel algorithm for the alternate application of the FEM and BEM to magnetic field problems with the open boundary is presented. This approach avoids the disadvantages of the typical numerical methods with the open boundary problem such as a great number of unknown values for the FEM and non-symmetric matrix for the Hybrid FE-BE method. The solution of the overall problems is obtained by iterative calculations accompanied with the new acceleration method.

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