• 제목/요약/키워드: Fringe analysis

검색결과 239건 처리시간 0.021초

미세변위 측정을 위한 스펙클 간섭계의 구성과 자동 Fringe 해석 (Speckle Interferometry and Automatic Fringe Analysis for Small Displacement Measurement)

  • 김성근;길상근;박한규
    • 대한전자공학회논문지
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    • 제26권8호
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    • pp.1282-1289
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    • 1989
  • Dual field speckle interferometry that is sensitive to the surface displacement of the object is constructed, and fringe patterns that have the displacement-informations are analysed using digital image processing. From 10\ulcorner to 80\ulcorner with respect to each specklegrams are obtained by double-exposure techniques, which are analysed by the proposed system and algorithm. Up to 10\ulcorner displacement, near measurable lower bound of Speckle Interferometry, fringe visibility is decreased due to decreasing fringe density, therefore relative errors are produced over 10% but over that displacement, relative errors are produced below 5%. Particularly, it is observed that spatial frequencies of each displacement are comparatively linear.

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등색프린지 데이터를 이용한 인장하중 판재 중앙 균열선단 주위의 하이브리드 광탄성 응력장 해석 (Hybrid Photoelastic Stress Analysis Around a Central Crack Tip in a Tensile Loaded Plate Using Isochromatic Data)

  • 백태현;첸레이
    • 대한기계학회논문집A
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    • 제31권12호
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    • pp.1200-1207
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    • 2007
  • An experimental test is presented for photoelastic stress analysis around a crack tip in tensile loaded plate. The hybrid method coupling photoelastsic fringe inputs calculated by finite element method and complex variable formulations involving conformal mappings and analytical continuity is used to calculate full-field stress around the crack tip in uniaxially loaded, finite width tensile plate. In order to accurately compare calculated fringes with experimental ones, both actual and regenerated photoelastic fringe patterns are two times multiplied and sharpened by digital image processing. Regenerated fringes by hybrid method are quite comparable to actual fringes. The experimental results indicate that Mode I stress intensity factor analyzed by the hybrid method are accurate within three percent compared with ones obtained by empirical equation and finite element analysis.

현대 가방 디자인에 나타난 술 장식의 표현유형과 미적 조형성 연구 (A study on the expression types and aesthetic formativeness of tassels and fringe in modern bag design)

  • 권기영
    • 복식문화연구
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    • 제28권4호
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    • pp.429-445
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    • 2020
  • The purpose of this study is to provide ideas for the development of bag design by analyzing the expression types and aesthetic formativeness of modern bag design using tassels and fringe given the newtro trend pursuing analog sensitivity in modern society. The methods and scope of this study are as follows. First, the related literature and internet data were reviewed in order to examine the expression types and characteristics of the bags of the West and East. Next, the definition and characteristics of tassel and fringe decoration in terms of the history of clothing were analyzed. Finally, the expression types and aesthetic formativeness of tassels and fringe were derived through the analysis of modern bag design shown in the fashion collections since 2010. The bags decorated with the tassels and fringe bring a variety of visual effects depending on the attachment position, direction and material composition, concentrating the gaze and radiating original style. In this study, the expression of tassels and fringe in modern bag design was classified into three types: surface decoration, shape variability, and object combination. Next, the aesthetic formativeness of modern bag design using tassels and fringe as decorative elements appeared through the mixture of heterogeneous materials and playfulness through imagination, exaggeration through extension of length and volume, and retro characteristics through reinterpretation of tradition. This study is expected to contribute to creative ideas of modern bag design which requires a global sense, which has been used in various cultures for a long time.

광탄성 직교이방성체의 물성치와 응력 프린지치 간이 측정법 (The simple measurement of physical properties and stress fringe value for photo-elastic orthotropic material)

  • 황재석;이광호
    • 대한기계학회논문집
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    • 제14권1호
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    • pp.23-36
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    • 1990
  • 본 연구에서는 Iosipescu의 전단 시험법을 사용하여 직접 측정한 응력 프린지 치(f$_{LT}$ )와 Sampson의 응력-광법칙에 의하여 구한 f$_{LT}$ 와 서로 비교하여 Sampson의 응력-광법칙이 f$_{LT}$ 를 간접적으로 측정하는데 사용할 수 있는가를 확 인한다. 그리고 직교 이방성 재료를 광탄성 실험에 의하여 해석하는 경우에 필요한 기본물성치와 응력 프린지치 관계를 구하여 이 관계가 상온과 고온에서도 성립하는가 를 확인하고 또 직접 물성치를 측정하는 대신에 각 물성치에 대응되는 응력 프린지치 에 의하여 물성치를 구하는 방법을 개발하는데 이 연구의 목적을 둔다.

광탄성 위상이동법을 이용한 주응력 방향 측정법 (Measurement of Principal Stress Direction by Photoelastic Phase Shifting Method)

  • 김명수;김환;백태현
    • 대한기계학회논문집A
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    • 제28권12호
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    • pp.1982-1989
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    • 2004
  • In photoelasticity, the directions of principal stresses are given by isoclinic fringe patterns. In this study, photoelastic theory is represented by Jones calculus and the photoelastic 8-step phase shifting method is described. A feasibility study using computer simulation is done to get isoclinics from photoelastic fringes of a circular disk under diametral compression. Fringe patterns of the disk are generated from the stress-optic law. The magnitudes of isoclinics obtained from the fringe patterns of computer simulation and experiment are compared with those of theory. The results are close between them. Then, the 8-step phase shifting method is applied to get distributions of isoclinics along the specified lines of a cuved beam plate under tensile load. Experimental results obtained from the phase shifting method were compared with those of finite element analysis (ANSYS). It is confirmed that measurement of isoclinic distributions is possible by use of photoelasitc phase shifting method.

Fourier 변환 모아레 간섭에 의한 이차원적 변형률 해석 (Tow-dimensional Strain Analysis by Fourier Transform Moire Interferometry)

  • 박두원;도전 태조;삼본 길춘;한응교
    • 비파괴검사학회지
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    • 제12권1호
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    • pp.16-24
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    • 1992
  • Moire interferometry using a diffraction grating and a laser is a powerful technique for analizing small deformation of a specimen. In the method, the x and y-directional fringe patterns are obtained by using the x and y-directional sets of two beams. If the both sets of two beams are simultaneously incident to the specimen, the x and y-directional fringe patterns are super imposed. In this case, it is difficult to separate each directional fringe pattern. Therefore each fringe pattern has been separately recorded by selecting each set of two beams. In order to analyze a two-dimensional strain changing with time, Moire interferometry using the two-dimensional fourier transform method is proposed and the x and y-directional fringes are separated. By this method, the thermal deformation of a glass plate is analyzed.

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Vibration Measurement Using a Fringe Pattern in Reflective Monochromatic Interferometry

  • Kim, Minsu;Yoon, Do-Young;Pahk, Heuijae
    • Journal of the Optical Society of Korea
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    • 제19권5호
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    • pp.494-502
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    • 2015
  • This paper introduces methods to measure vibration using a fringe pattern. These methods use variations of a fringe pattern in reflective monochromatic interferometry, without additional components. With the proposed methods we measured the vibrations of four waveform with amplitude 100 nm. When the vibrational amplitude is greater than a quarter wavelength of the light employed, however, the measured results are distorted due to ambiguity. Thus we propose advanced methods to solve this problem, and also measure the vibrations of two waveformswith an amplitude of $1{\mu}m$. To verify the performance of the proposed methods, we compare the results to those from an accelerometer. Multifrequency vibrations of 1, 5, 10, and 20 Hz are measured by both techniques, and the results compared in the frequency domain.

도시화에 따른 도시외곽지 마을의 변화 특성 분석에 관한 연구 (A Study on the Transforming Characteristics Analysis of Village in the Urban Fringe)

  • 김영이;김묘정;하재명
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 2002년도 추계학술발표대회
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    • pp.203-208
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    • 2002
  • The purpose of this study is to examine the transforming characteristics of village at the urban fringe, which are influenced by the urbanization. Three areas in the urban fringe are selected for the case study. The changed conditions in the spatial structure of those areas are reviewed through following factors : street system, an entrance of village, a boundary of village, community facility, development density, housing type, building use. The transforming characteristics are analyzed as a result of the research. In result, the community facility, development density, housing type and building use are changed largly in the transforming characteristics.

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행위자연계망이론을 통한 영국 도시교외지역 관리시책의 운영과정 특성 분석 -테임즈 체이스 마을 숲 조성 시책을 사례로- (An Analysis of the Urban Fringe Management Initiative's Operational Process in UK Using the Actor Network Theory - A Case Study of Thames Chase Community Forest Initiative -)

  • 김용범;박재홍;천성환
    • 농촌계획
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    • 제13권1호
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    • pp.97-109
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    • 2007
  • The purpose of this research was to investigate and analyse how Community Forest Initiatives as urban fringe management initiatives made alliances with a variety of interest groups, enrol them in the urban fringe management processes using the Actor Network Theory. The Thames Chase Community Forest Initiative was selected and its area of operation included a $97 km^2$ area of green-belt area in East London. It was a instrument far improving and protecting the unique characteristics of the countryside landscape from urban developments as well as evaluating the impact of forestry inclusion in land use planning in the urban fringe. It was operated through a tiered structure comprising the Thames Chase Joint Committee and the management team. They employed a variety of devices to speak with one voice to bring about an effective operation process and to secure the enrolment of a variety of interest groups in its operational processes. Of note, the initiative's actor network impacted on improvement to and management of the countryside landscape despite not owning any land itself. As a result, when urban fringe management initiatives will be launched in South Korea to achieve a more effective and efficient urban fringe management, local councillors and representatives from public and non-government bodies should be more responsive to local communities' views and needs and work more vigorously on their behalf through lobbying, seeking media support, and so on. Moreover, better understanding and communication between local authorities' officers and management initiatives' teams are essential to avoid duplication of work practice.

혼합모드 크랙 선단응력의 광탄성해석 (Photoelastic Analysis of Stress Field in the Neighborhood of a Mixed Mode Crack Tip)

  • 백태현
    • 대한기계학회논문집
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    • 제16권11호
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    • pp.2072-2081
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    • 1992
  • 본 연구에서는 다매개변수(multiple parameters)사용시 모드 I과 모드 II에 나타나는 응력장의 특성을 분석하였고, 실험적으로 계산된 응력강도계수를 이론적인 수치해석 및 다른 실험결과에서 얻어진 값과 비교하였다.