• 제목/요약/키워드: Directionality

검색결과 264건 처리시간 0.023초

금형의 표면정도와 가공방향에 따른 판재의 마찰특성 (Friction Characteristics of Sheets for The Surface Finish and The Stoning Directions of The Dies)

  • 김동환;조형근;김병민;오세욱;박춘달;황지선
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집A
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    • pp.814-820
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    • 2000
  • This papers investigates the combined effects of parameters such as die surface finish, die directionality of stoning, contact pressure and draw speed on the resulting friction factor. Also, this study show the correlation between the NN(Neural Network) and DOE (Design of Experiments) to reduce the number of experiments without the loss of the effects of parameter upon friction factor. The experiments were run in random order with at least three replicates. It was found that the directional stoning orthogonal to the pulling direction is lower friction than directional stoning parallel to the pulling direction using FCD55 die and SPCEN

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점탄성-복합재 박판 블레이드 구조물의 진동 해석 (Dynamic Analysis of Viscoelastic Composite Thin-Walled Blade Structures)

  • 신재현;나성수;박철휴
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 추계학술대회
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    • pp.1684-1689
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    • 2003
  • This paper concerns the analytical modeling and dynamic analysis of advanced cantilevered blade structure implemented by a dual approach based on structural tailoring and viscoelastic materials technology. Whereas structural tailoring uses the directionality properties of advanced composite materials, the passive materials technology exploits the damping capabilities of viscoelastic material(VEM) embedded into the host structure. The structure is modeled as a composite thin-walled beam incorporating a number of nonclassical features such as transverse shear, secondary warping, anisotropy of constituent materials, and rotary inertias. The case of VEM spreaded over the entire span of the structure is considered. The displayed numerical results provide a comprehensive picture of the synergisitic implications of the application of both techniques, namely, the tailoring and damping technology on vibration response of thin-walled beam structure exposed to external time-dependent excitations.

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Directionality of O-Phthaladehyde adsorbed on H-Si(100) Surface Using NEXAFS and HRPES

  • 김기정;박선민;임희선;김봉수;이한길
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2010년도 제39회 하계학술대회 초록집
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    • pp.79-79
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    • 2010
  • The electronic and adsorption structure of O-Phthaladehyde (OPA) on the H-Si(100) surface was investigated by using Near Edge X-ray Fine Structure (NEXAFS) and high resolution photoemission spectroscopy (HRPES). We confirmed that the OPA grown on the H-Si(100) surface showed good dependency with about 60 degree tilting angle using NEXAFS and a single O 1s peak by using HRPES. Hydrogen atom passivated on the Si(100) surface was found to be a seed for making one dimensional organic line that uses a chain reaction as the H-Si(100) surface was compared with the hydrogen free Si(100) surface. Through the spectral analysis, we will demonstrate 1-D directional formation of OPA on H-Si(100) surface using NEXAFS and HRPES.

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3D Projection Screen using Advanced Volume Holography

  • Okamoto, Masaaki;Shimizu, Eiji
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.1005-1008
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    • 2002
  • The authors introduce 3D display systems developed in our laboratories for recent ten years. Those are mainly realized by several technologies in holography: electro-holography. holographic stereogram, holographic optical elements (HOE) and hologram screen. We are currently focusing the development of 3D projection screen without glasses. Powerful directionality of the light beam is required for 3D projection screen unlike 2D type. We succeeded in achieving the superior diffractive efficiency of hologram screen that is based on the advanced volume holography. This technology is extensively useful to retrieve the Bragg condition of volume hologram in the three-dimensional space. Owing to this technology we could establish the principle of multi-view projection screen and have confirmed the case of 4 viewing points.

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레이저 빔에 의한 YBCO 표면변조 연구 (Study on YBCO Surface Modification by Laser Beam)

  • 정영식;이상렬
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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    • pp.129-132
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    • 1996
  • Surface modification like cone formation on Pulsed laser deposition (PLD) occurs in YBCO target surface irradiated by laser beam. Cone formation results in a reduction of deposition rate, so that it is significant obstacles to an efficient deposition process. With the change of various conditions such as the number of laser shot, target density, direction of incoming laser beam, we have systematically analyzed the modification of target surface. Because cones formed by beam-target interactions grow in direction of incoming laser beam, we have used the method of rotating the target position by 180$^{\circ}$ with the same number and position of laser shot. Experimental results of losing the directionality and changing the shape of cones formed on laser irradiated YBCO target surface is obtained by the SEM image. Also, we have observed that the size of cones formed on target by pulsed laser became larger with increasing the number of laser shots.

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A Resetting Scheme for Process Parameters using the Mahalanobis-Taguchi System

  • Park, Chang-Soon
    • 응용통계연구
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    • 제25권4호
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    • pp.589-603
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    • 2012
  • Mahalanobis-Taguchi system(MTS) is a statistical tool for classifying the normal group and abnormal group in multivariate data structures. In addition to the classification itself, the MTS uses a method for selecting variables useful for the classification. This method can be used efficiently especially when the abnormal group data are scattered without a specific directionality. When the feedback adjustment procedure through the measurements of the process output for controlling process input variables is not practically possible, the reset procedure can be an alternative one. This article proposes a reset procedure using the MTS. Moreover, a method for identifying input variables to reset is also proposed by the use of the contribution. The identification of the root-cause parameters using the existing dimension-reduced contribution tends to be difficult due to the variety of correlation relationships of multivariate data structures. However, it became possible to provide an improved decision when used together with the location-centered contribution and the individual-parameter contribution.

금형의 표면정도와 가공방향에 따른 판재의 마찰특성 (Friction Characteristics of Sheets for The Surface Finish and The Stoning Directions of the Dies)

  • 김동환;김병민;오세욱;박춘달;황지선
    • 대한기계학회논문집A
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    • 제25권2호
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    • pp.312-322
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    • 2001
  • This paper investigates the combined effects of parameters such as die surface finish, die directionality of stoning contact pressure and draw speed on the resulting coefficient of friction. Also, this study show the correlation between the NN(Neural Network) and DOE(Design of Experiments) to reduce the number of experiments without the loss of the effects of parameter upon coefficient of friction. The experiments were run in random order with at least three replicates. It was found that the directional stoning orthogonal to the pulling direction is lower friction than directional stoning parallel to the pulling directi on using FCD55 die and SPCEN.

진공네트웍 압력분포 해석의 일반화 (Generalization of the pressure profile analysis in a vacuum network)

  • 인상렬
    • 한국진공학회지
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    • 제8권1호
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    • pp.1-8
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    • 1999
  • 형태와 진공특성이 다른 여러 용기와 도관들로 구성된 진공네트웍의 압력분포를 계산할 때 단면이 서로 틀린 요소들의 연결부에서 입출구효과에 의해 발생하는 압력강하를 기체가 흐르는 방향에 상관없이 자동적으로 고려할 수 있는 경계조건을 만들었다. 또 원추형 도관처럼 단면이 변화하는 요소를 포함하고 있는 경우 시스템이 방향성을 가지지 않도록 도관 내에서의 압력강하를 보정하는 방법에 대해 소개한다. 개발된 경계조건을 간단한 예제 진공시스템에 적용하여 입자평형식에 근거를 둔 연립방정식을 작성하고 해를 구하는 과정을 구체적으로 설명한다.

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K-Means Algorithm Using Texture Directionality for Natural Image Segmentation

  • Kasao, Atsushi;Nakajima, Masayuki
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송공학회 1998년도 Proceedings of International Workshop on Advanced Image Technology
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    • pp.23-28
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    • 1998
  • The goal of this research is to describe relations between impressions and elements in an image (i.e. color, texture and contours). Adequate image segmentation technique to extract these elements is required. We think that a sketch and a realistic painting are examples of optimal segmented images for our purpose because brush strokes are seem to be segmented areas and realistic paintings should remain the same impression as the model. For the reason, in this paper the segmentation technique which can create realistic painting-like segmentation is exploited. It is shown that the realistic painting-like segmentation is suitable for analyzing images.

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Grid based Enhanced Routing Scheme in MANET

  • Bok, Kyoungsoo;Yoon, Sooyong;Lim, Jongtae;Yoo, Jaesoo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제10권5호
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    • pp.2218-2244
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    • 2016
  • In this paper, we propose a hybrid routing scheme that utilizes location information to support reliable data transmission in mobile ad hoc networks. The proposed scheme determines and maintains routing path by considering the directionality and connectivity of nodes using grid zones and information on neighbor nodes. In addition, it generates alternative paths with consideration for node distance and reliability. To show the superiority of the proposed routing scheme, a performance evaluation was conducted using simulations. The performance evaluation results show that the proposed scheme offers faster and more reliable data transmission than the existing routing schemes, and the number of messages decreases by approximately 31% compared to the existing schemes on average.