• Title/Summary/Keyword: contour analysis

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

  • Ju, Jang-Kyu;Lee, Ki-Young;Kim, Jung-Kuk
    • Proceedings of the KIEE Conference
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    • 2006.10c
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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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    • v.19 no.10
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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.

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

  • 조성익;박경윤;최규홍;최원식
    • Korean Journal of Remote Sensing
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    • v.2 no.2
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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
    • Journal of Ocean Engineering and Technology
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    • v.36 no.2
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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.

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

  • Choi, Eun-Jin;Suh, Doug-Young
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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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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Development of Computer Aided System for Error Assessoment for Multi-axis Machine Tools using the Double Ball Bar (기구볼바를 이용한 공작기계의 오차평가 시스템 개발)

  • 문준희;박희재;주종남
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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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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A Study on Plastic Behaviour of Cruciform Welding Joint with Variation of Contour (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))

  • Dong-Suk,Um;Byoung-Yoon,Kang
    • Bulletin of the Society of Naval Architects of Korea
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    • v.18 no.4
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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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Upper Bound Analysis on the Forging of Gear-Like Components (기어류 부품의 단조에 관한 상계해석)

  • Min, G.S.;Park, J.U.;Lee, H.C.
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.2
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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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Automatic Generation of Digital Elevation Model from 2D Terrain Map Using Graph-theoretic Algorithms (그래픽이론적 알고리즘들을 이용한 2차원 지형도로 부터 DEM 의 자동생성방법)

  • 구자영
    • Korean Journal of Remote Sensing
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    • v.9 no.2
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    • pp.21-34
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    • 1993
  • Digitalized topographic information is necessary for many areas such as landscape analysis, civil engineering planning and design, and geographic information systems. It can also be used in flight simulator and automatic navigation of unmanned plane if it is stored in computer in relevant format. Topographic information is coded with various symbols including contour lines, and is analyzed by trained personnels. The information should be stored in computer for automatic analysis, but it requires a lot of time and manpower to enter the contours using manual input devices such as digitizing tablet. This paper deals with automatic extraction and reconstruction of 3D topographic information from 2D terrain map. Several algorithms were developed in this work including contour segment finding algorithm and contour segment linking algorithm. The algorithm were tested using real 2D terrain map.

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
    • Progress in Medical Physics
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    • v.10 no.3
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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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