• 제목/요약/키워드: contour analysis

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기울기추적파를 이용한 심전도의 기저선 변동 제거방법의 비교 연구 (A Study on Elimination Methods of Baseline Wander for ECG using Slope Tracing Waves)

  • 주장규;이기영;김정국
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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    • pp.247-249
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    • 2006
  • This paper describes a new method to eliminate the baseline wander for ECG based on waveform morphology analysis. This method uses the descending slope tracing waves[3] to separate the baseline wander from ECG and approximates the separated baseline wander to a corresponding approximated S-waves contour, and finally, subtracts the approximated S-waves contour from the original ECG. To verify its efficacy and validity in practical applications, this method has been applied to MIT/BIH database and compares this method with the other method employing the ascending slope tracing waves to remove a baseline from ECG[4].

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FEM Analysis of Plasticity-induced Error on Measurement of Welding Residual Stress by the Contour Method

  • Shin, Shang-Hyon
    • Journal of Mechanical Science and Technology
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    • 제19권10호
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    • pp.1885-1890
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    • 2005
  • The contour method relies on deformations that occur when a residually stressed component is cut along a plane. The method is based on the elastic superposition principle. When plasticity is involved in the relaxation process, stress error in the resulting measurement of residual stress would be caused. During the cutting the specimen is constrained at a location along the cut so that deformations are restrained as much as possible during cutting. With proper selection of the constraining location the plasticity effect can also be minimized. Typical patterns of longitudinal welding residual stress state were taken to assess the plasticity effect along with constraining locations.

Landsat 영상과 DTM 자료의 하천유역 해석에의 응용기법 개발 (Applications of Landsat Imagery and Digital Terrain Model Data to River Basin Analyses)

  • 조성익;박경윤;최규홍;최원식
    • 대한원격탐사학회지
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    • 제2권2호
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    • pp.117-131
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    • 1986
  • The purpose of this study was to develop techniques acquiring hydrologic parameters that affect runoff conditions from Landsat imagery. Runoff conditions in a study area were analyzed by employing the U.S. Soil Conservation Service(SCS) Method. SCS runoff curve numbers(CN) were estimated by the computer analysis of Landsat imagery and digiral terrain model(DTM) data. The SCS Method requires land use/cover and soil conditions of the area as input parameters. A land use/cover map of 5 hydrological classes was produced from the Landsat multi-spectral scannerr imagery. Slope-gradient and contour and contour maps were also made using the DTM topographic data. Inundation areas depending on reservoir levels were able to be mapped on the Landsat scene by combining the contour data.

Analysis of Steady Vortex Rings Using Contour Dynamics Method for Fluid Velocity

  • Choi, Yoon-Rak
    • 한국해양공학회지
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    • 제36권2호
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    • pp.108-114
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    • 2022
  • Most studies on the shape of the steady vortex ring have been based on the Stokes stream function approach. In this study, the velocity approach is introduced as a trial approach. A contour dynamics method for fluid velocity is used to analyze the Norbury-Fraenkel family of vortex rings. Analytic integration is performed over the logarithmic-singular segment. A system of nonlinear equations for the discretized shape of the vortex core is formulated using the material boundary condition of the core. An additional condition for the velocities of the vortical and impulse centers is introduced to complete the system of equations. Numerical solutions are successfully obtained for the system of nonlinear equations using the iterative scheme. Specifically, the evaluation of the kinetic energy in terms of line integrals is examined closely. The results of the proposed method are compared with those of the stream function approaches. The results show good agreement, and thereby, confirm the validity of the proposed method.

방사선 치료 계획 장치를 위한 의료 영상의 3차원적 자동 경계선 검출에 관한 연구 (A Study on 3Dimensional Automatic Boundaries Detection on Medical Images or Radiation Therapy Planning)

  • 최은진;서의영
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1997년도 추계학술대회
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    • pp.172-175
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    • 1997
  • Outline contour is detected firstly to simulate dose distribution in radiation therapy planning system. In this paper, we developed automatic contour detection system using temporal and spatial relationships of image sequences. The low level image analysis involves the use of directional gradient edge operators and Laplacian operator. The High level portion of algorithm uses a knowledge-based strategy that incorporates fuzzy resoning method.

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기구볼바를 이용한 공작기계의 오차평가 시스템 개발 (Development of Computer Aided System for Error Assessoment for Multi-axis Machine Tools using the Double Ball Bar)

  • 문준희;박희재;주종남
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1994년도 추계학술대회 논문집
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    • pp.336-342
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    • 1994
  • This paper presents an useful technique for assessing the volumetric error in multi_axis machine tools using the kinematic double ball bar and 3 dimensional spherical contouring. The developed system proposes the 3 dimensional spherical contour for the error analysis. The developed system input the measured radial data, analysing the volumetric errors such as positional, strightness, angle, and squareness errors, etc. The developed system has been tested in a practical machine tool, and showed high

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십자형(十字形) 필렛 용접(熔接) 이음의 형상변화(形狀變化)에 따른 소성적(塑性的) 거동(擧動)에 대한 연구(硏究) (A Study on Plastic Behaviour of Cruciform Welding Joint with Variation of Contour)

  • 엄동석;강병윤
    • 대한조선학회지
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    • 제18권4호
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    • pp.21-29
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    • 1981
  • In this paper, plastic behavior and plastic strength of cruciform fillet welded joint under tension is investigated by finite element method. Attension is focussed, in particular, on the effect of geometry of fillet weld including its contour, size and penetration. And the approximate analysis of welded joint have been carried out from a simple model constructed by three zone, ie, base metal, heat affected zone, and weld metal.

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기어류 부품의 단조에 관한 상계해석 (Upper Bound Analysis on the Forging of Gear-Like Components)

  • Min, G.S.;Park, J.U.;Lee, H.C.
    • 한국정밀공학회지
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    • 제14권2호
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    • pp.102-112
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    • 1997
  • This paper describes the method that can construct kinematically admissible velocity fields for forging of gear-like components which have tooth shape around the cylinder. The kinematically admissible velo- city fields for the various gear-like components, involute spur gear, trapezoidal spline, square spline, ser- ration and trochoidal gear, were constructed by pilling up the velocity components according to the shape of tooth and billet. The billets, of hollow and solid, were Al 2218 and 2024. To verify the method, the analyses and experiments were carried out and compared with each other. For analyses, the half pitches of com- ponents were divided into several deformation regions based on their tooth profile. A neutral surface was used to represent the inner flow of material during forging. Its location varied with the energy optimazation and its contour varied with the number of teeth. In experiment, the contour of material filling up the tooth zone is hyperbolic curve caused by the frictional drag on the interface of die-wall/workpiece but, in the analysis, it is an arc which retains the same contour during all forging operation.

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그래픽이론적 알고리즘들을 이용한 2차원 지형도로 부터 DEM 의 자동생성방법 (Automatic Generation of Digital Elevation Model from 2D Terrain Map Using Graph-theoretic Algorithms)

  • 구자영
    • 대한원격탐사학회지
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    • 제9권2호
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    • pp.21-34
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    • 1993
  • 디지탈화된 지형 정보는 조망분석, 토목계획이나 설계, 또는 지리정보시스템등 여러 분야 에 필요한 요소가 된다. 또한 컴퓨터에 적절한 형식으로 입력된 지형정보는 모의 비행훈련이나 무인비행장치에서도 사용될 수 있다. 지형정보는 지도위에 등고선을 비롯한 여러가지 기호들로 표시되어 있어서 훈련된 요원에 의해 분석된다. 자동분석을 위해서는 컴퓨터에 입력되어야 하는 데 디지타이징 타블렛과 같은 장비를 사용하여 수동으로 입력하는 것은 많은 시간과 인력을 필요 로 한다. 본 논문에서는 이차원 지형도로부터 삼차원 지형정보를 자동적으로 추출하는 방법을 다 루고 있다. 등고선 조각연결 알고리즘을 포함하는 몇 가지 알고리즘들이 제안되었고 실제 지형도 를 사용하여 실험되었다.

Evaluation of Cardiac Function Analysis System Using Magnetic Resonance Images

  • Tae, Ki-Sik;Suh, Tae-Suk;Choe, Bo-Young;Lee, Hyoung-Koo;Shinn, Kyung-Sub;Jung, Seung-Eun;Lee, Jae-Moon
    • 한국의학물리학회지:의학물리
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    • 제10권3호
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    • pp.159-168
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    • 1999
  • Cardiac disease is one of the leading causes of death in Korea. In quantitative analysis of cardiac function and morphological information by three-dimensional reconstruction of magnetic resonance images, left ventricle provides an important role functionally and physiologically. However, existing procedures mostly rely on the extensive human interaction and are seldom evaluated on clinical applications. In this study, we developed a system which could perform automatic extraction of enpicardial and endocardial contour and analysis of cardiac function to evaluate reliability and stability of each system comparing with the result of ARGUS system offered 1.5T Siemens MRI system and manual method performed by clinicians. For various aspects, we investigated reliability of each system by compared with left ventricular contour, end-diastolic volume (EDV), end-systolic volume (ESV), stock volume (SV), ejection fraction (EF), cardiac output (CO) and wall thickness (WT). When comparing with manual method, extracted results of developed process using minimum error threshold (MET) method that automatically extracts contour from cardiac MR images and ARGUS system were demonstrated as successful rate 90% of the contour extraction. When calculating cardiac function parameters using MET and comparing with using correlation coefficients analysis method, the process extracts endocardial and epicardial contour using MET, values from automatic and ARGUS method agreed with manual values within :t 3% average error. It was successfully demonstrated that automatic method using threshold technique could provide high potential for assessing of each parameters with relatively high reliability compared with manual method. In this study, the method developed in this study could reduce processing time compared with ARGUS and manual method due to a simple threshold technique. This method is useful for diagnosis of cardiac disease, simulating physiological function and amount of blood flow of left ventricle. In addition, this method could be valuable in developing automatic systems in order to apply to other deformable image models.

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