• Title/Summary/Keyword: Point-extraction

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A QRS pattern analysis algorithm by improved significant point extraction method (개선된 특성점 검출 기법에 의한 QRS 패턴해석)

  • Hwang, Seon-Cheol;Lee, Byung-Chae;Nam, Seung-Woo;Lee, Myoung-Ho
    • Proceedings of the KOSOMBE Conference
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    • v.1991 no.05
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    • pp.51-55
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    • 1991
  • This paper describes an algorithm of pattern analysis of ECG signals by significant points extraction method. The significant points can be extracted by modified zerocrossing method, which method determines the real significant point among the significant point candidates by zerocrossing method and slope rate of left side and right side. This modified zerocrossing method improves the accuracy of detection of real significant point position. This paper also describes the pattern matching algorithm by a hierarchical AND/OR graph of ECG signals. The decomposition of ECG signals by a hierarchical AND/OR graph can make the pattern matching process easy and fast. Furthermore the pattern matching to the significant points reduces the processing time of ECG analysis.

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A Study on Medial Surface Extraction from Point Samples on 3D Closed Surfaces in Shell Shapes (셸 형상의 3차원 폐곡면상에서 추출된 점데이터군으로부터 중립곡면 계산에 관한 연구)

  • Woo, Hyuck-Je
    • Korean Journal of Computational Design and Engineering
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    • v.15 no.1
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    • pp.33-42
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    • 2010
  • In this study, new medial surface calculation methods using Voronoi diagrams are investigated for the point samples extracted on closed surface models. The medial surface is defined by the closure of all points having more than one closest point on the shape boundary. It is a one of essential geometric information in 3D and can be used in many areas such as 3D shape analysis, dimension reduction, freeform shape deformation, image processing, computer vision, FEM analysis, etc. In industrial parts, the idealized solid parts and shell shapes including sharp edges and vertices are frequently used. Other medial surface extraction methods using Voronoi diagram have inherent separation and branch problems, so that they are not appropriate to the sharp edged objects and have difficulties to be applied to industrial parts. In addition, the branched surfaces on sharp edges in shell shapes should be eliminated to obtain representative medial shapes. In order to avoid separation and branch problems, the new approach by analyzing the shapes and specially sampling on surfaces has been developed.

Feature curve extraction from point clouds via developable strip intersection

  • Lee, Kai Wah;Bo, Pengbo
    • Journal of Computational Design and Engineering
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    • v.3 no.2
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    • pp.102-111
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    • 2016
  • In this paper, we study the problem of computing smooth feature curves from CAD type point clouds models. The proposed method reconstructs feature curves from the intersections of developable strip pairs which approximate the regions along both sides of the features. The generation of developable surfaces is based on a linear approximation of the given point cloud through a variational shape approximation approach. A line segment sequencing algorithm is proposed for collecting feature line segments into different feature sequences as well as sequential groups of data points. A developable surface approximation procedure is employed to refine incident approximation planes of data points into developable strips. Some experimental results are included to demonstrate the performance of the proposed method.

The Storage Property of Squid Viscera by Supercritical Carbon Dioxide Extraction

  • Lee, Min-Kyung;Yoo, Hong-Suk;Pack, Hyun-Duk;Chun, Byung-Soo
    • Journal of Marine Bioscience and Biotechnology
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    • v.2 no.1
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    • pp.55-59
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    • 2007
  • The oil and concentrated protein powder from squid viscera was extracted and recovered by a semi-batch supercritical carbon dioxide ($SCO_2$) extraction system and the degree of oxidation in the extracted oil was measured in order to compare with extracted oils using organic solvents. The degree of storage in treated squid viscera by $SCO_2$ extraction was measured in order to compare with untreated squid viscera. As results obtained, it was found that the auto-oxidation of the oils using $SCO_2$ extraction occurred very slowly compared to the oils by organic solvent extraction. And the treated squid viscera by $SCO_2$ extraction was reached the point of initial rottenness slowly than untreated squid viscera.

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Optimization of Crude Papain Extraction from Papaya Latex Using Response Surface Methodology (반응표면 분석법에 의한 crude papain 추출 조건의 최적화)

  • Oh, Hoon-Il;Oh, Sang-Joon;Kim, Jeong-Mee
    • Korean Journal of Food Science and Technology
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    • v.29 no.3
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    • pp.509-515
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    • 1997
  • Crude papain was extracted from papaya latex under various conditions. Extraction conditions of crude papain were optimized by the response surface methodology (RSM). Extraction yield of papain was affected by concentration of $NaHSO_3$, extraction time and pH. Three independent factors were chosen to determine their effects on the various responses and the function was expressed in terms of a quadratic polynomial equation, which measures the linear, quadratic and interaction effects. According to the results of RSM, the stationary point for quantitatively dependent variable was found to be the maximum point for extraction yield. Optimum conditions of papain extraction were 4% of $NaHSO_3$, 120 min of extraction time and pH 7.6. Under these conditions, 793.16 mg of papain per g latex was extracted from papaya latex.

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Gabor Descriptors Extraction in the SURF Feature Point for Improvement Accuracy in Face Recognition (얼굴 인식의 정확도 향상을 위한 SURF 특징점에서의 Gabor 기술어 추출)

  • Lee, Jae-Yong;Kim, Ji-Eun;Oh, Seoung-Jun
    • Journal of Broadcast Engineering
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    • v.17 no.5
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    • pp.808-816
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    • 2012
  • Face recognition has been actively studied and developed in various fields. In recent years, interest point extraction algorithms mainly used for object recognition were being applied to face recognition. The SURF(Speeded Up Robust Features) algorithm was used in this paper which was one of typical interest point extraction algorithms. Generally, the interest points extracted from human faces are less distinctive than the interest points extracted from objects due to the similar shapes of human faces. Thus, the accuracy of the face recognition using SURF tends to be low. In order to improve it, we propose a face recognition algorithm which performs interest point extraction by SURF and the Gabor wavelet transform to extract descriptors from the interest points. In the result, the proposed method shows around 23% better recognition accuracy than SURF-based conventional methods.

A Background Segmentation and Feature Point Extraction Method of Human Motion Recognition (동작인식을 위한 배경 분할 및 특징점 추출 방법)

  • You, Hwi-Jong;Kim, Tae-Young
    • Journal of Korea Game Society
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    • v.11 no.2
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    • pp.161-166
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    • 2011
  • In this paper, we propose a novel background segmentation and feature point extraction method of a human motion for the augmented reality game. First, our method transforms input image from RGB color space to HSV color space, then segments a skin colored area using double threshold of H, S value. And it also segments a moving area using the time difference images and then removes the noise of the area using the Hessian affine region detector. The skin colored area with the moving area is segmented as a human motion. Next, the feature points for the human motion are extracted by calculating the center point for each block in the previously obtained image. The experiments on various input images show that our method is capable of correct background segmentation and feature points extraction 12 frames per second.

A 3D Face Reconstruction Method Robust to Errors of Automatic Facial Feature Point Extraction (얼굴 특징점 자동 추출 오류에 강인한 3차원 얼굴 복원 방법)

  • Lee, Youn-Joo;Lee, Sung-Joo;Park, Kang-Ryoung;Kim, Jai-Hie
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.48 no.1
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    • pp.122-131
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    • 2011
  • A widely used single image-based 3D face reconstruction method, 3D morphable shape model, reconstructs an accurate 3D facial shape when 2D facial feature points are correctly extracted from an input face image. However, in the case that a user's cooperation is not available such as a real-time 3D face reconstruction system, this method can be vulnerable to the errors of automatic facial feature point extraction. In order to solve this problem, we automatically classify extracted facial feature points into two groups, erroneous and correct ones, and then reconstruct a 3D facial shape by using only the correctly extracted facial feature points. The experimental results showed that the 3D reconstruction performance of the proposed method was remarkably improved compared to that of the previous method which does not consider the errors of automatic facial feature point extraction.

A Comparison of Data Extraction Techniques and an Implementation of Data Extraction Technique using Index DB -S Bank Case- (원천 시스템 환경을 고려한 데이터 추출 방식의 비교 및 Index DB를 이용한 추출 방식의 구현 -ㅅ 은행 사례를 중심으로-)

  • 김기운
    • Korean Management Science Review
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    • v.20 no.2
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    • pp.1-16
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    • 2003
  • Previous research on data extraction and integration for data warehousing has concentrated mainly on the relational DBMS or partly on the object-oriented DBMS. Mostly, it describes issues related with the change data (deltas) capture and the incremental update by using the triggering technique of active database systems. But, little attention has been paid to data extraction approaches from other types of source systems like hierarchical DBMS, etc. and from source systems without triggering capability. This paper argues, from the practical point of view, that we need to consider not only the types of information sources and capabilities of ETT tools but also other factors of source systems such as operational characteristics (i.e., whether they support DBMS log, user log or no log, timestamp), and DBMS characteristics (i.e., whether they have the triggering capability or not, etc), in order to find out appropriate data extraction techniques that could be applied to different source systems. Having applied several different data extraction techniques (e.g., DBMS log, user log, triggering, timestamp-based extraction, file comparison) to S bank's source systems (e.g., IMS, DB2, ORACLE, and SAM file), we discovered that data extraction techniques available in a commercial ETT tool do not completely support data extraction from the DBMS log of IMS system. For such IMS systems, a new date extraction technique is proposed which first creates Index database and then updates the data warehouse using the Index database. We illustrates this technique using an example application.