• Title/Summary/Keyword: cubic spline

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Appendix Extraction from Ultrasound Image using ART2 (ART2 알고리즘을 이용한 초음파 영상에서의 충수 추출)

  • Kim, Kwang Baek
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.11
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    • pp.2540-2545
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    • 2015
  • In this paper, we propose a novel method to extract appendix from ultrasound image automatically to avoid such subjectivity issue. In the process, we apply a series of image processing algorithms such as Ends_in search stretching for emphasizing brightness contrast and binarization, region labelling, and cubic spline interpolation for extracting lower bound fasicia line that is the base of extracting the appendix. Knowing that the appendix is located at the lower organ area below the bottom fascia line, we conduct a series of image processing techniques to find the fascia line correctly. And then we apply ART2 algorithm to the organ area in order to extract appendix accurately. Through experiment, the effectiveness of the proposed method is verified based on the field experts' evaluations.

Extraction and analysis of rotator cuff tear area Using Clustering Based Quantization (클러스터링 기법 기반 양자화를 이용한 회전근개 건 파열 영역 추출 및 분석)

  • Park, Ji-Hun;Choi, Cheol-Ho;Song, Yu-Seon;Kim, Kwang Beak
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2017.10a
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    • pp.494-496
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    • 2017
  • 본 논문에서는 기존의 회전근개 건 파열 추출 방법을 개선하기 위하여 초음파 영상에서 환자 정보를 제거하여 ROI 영역을 추출한다. 추출된 ROI 영역에서 명암 대비를 강조하기 위해 기존의 사다리꼴 형태의 퍼지 스트레칭 기법에서 소속 함수를 개선한 퍼지 스트레칭 기법을 적용하여 힘줄과 연골 영역을 효과적으로 강조한다. 강조된 ROI 영역에서 Max-Min 이진화와 8방향 윤곽선 추적 기법 및 Monoton Cubic Spline 기법을 적용한 후에 라벨링 기법을 적용하여 힘줄 및 연골 영역을 추출한다. 추출된 힘줄과 연골 영역을 이용하여 회전근개 영역을 추출한다. 추출한 회전근개 영역에 SOM 기반 양자화 기법을 적용하여 회전근개 건 파열 영역을 추출한다. 제안된 회전근개 건 파열 영역 추출 방법을 다양한 초음파 회전근개 건 파열 영상을 대상으로 실험한 결과, 제안된 회전근개 건 파열 영역이 기존의 추출 방법보다 TPR 값이 증가되어 회전근개 건 파열 분석에 효과적인 것을 확인할 수 있었다.

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Extraction of Ganglion from Ultrasonic Images Using Nonlinear Fuzzy Stretching and Fuzzy Clustering Method (비선형 퍼지 스트레칭 기법과 퍼지 클러스터링 기법을 이용한 초음파 영상에서의 결절종 추출)

  • Cho, Jae-Hun;Lee, Jae-Min;Kim, Kwang Baek
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2017.10a
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    • pp.68-70
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    • 2017
  • 본 논문에서는 결절종을 추출하는 과정에서 비선형 퍼지 스트레칭 기법과 FCM 기반 양자화 기법을 적용하여 결절종을 추출하는 방법을 제안한다. 제안된 결절종 추출 방법은 비선형 형태의 퍼지 스트레칭 기법을 적용하여 명암 대비를 강조한 ROI 영역에 Monotone Cubic Spline기법과 FCM 기반 양자화 기법을 적용하여 Monotone Cubic Spline기법이 적용된 상단 부분을 분리한다. 분리된 상단 영역들에서 결절종이 명암도가 낮고 타원 형태를 가진다는 형태학적 특징을 이용하기 위해서 침식 기법을 적용하여 결절종의 후보 영역을 추출하고 8 방향 윤곽선 추적 알고리즘을 적용하여 잡음 영역을 제거한다. 잡음이 제거된 결절종 후보 영역에서 최종 결절종 영역을 추출하기 위해 라벨링 기법을 적용한다. 제안된 결절종 추출 방법의 성능을 분석하기 위해서 필립스 초음파 장비를 이용하여 20명 환자에서 획득한 20장의 영상을 대상으로 실험한 결과 기존의 방법보다 TPR(Ture Positive Rate)이 높게 나타나는 것을 확인하였다.

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Analysis of Gear Noise and Design for Gear Noise Reduction (저소음 치차설계를 위한 치형수정에 관한 연구)

  • Yoon, Koo-Young;Park, Wang-Jun
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.4
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    • pp.129-135
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    • 1996
  • The area of gear vibration and noise, has recently been the focus of many studies. The proper kinematic and geometric design of gears, the mathematical modeling of gear system are essential for a good design. This work present a gear disign for reducing noise, and practical approaches used for machinery noise reduction slong with the summary of methods available for predicting gear noise in terms of the transmis- sion error, and show a comparative study with other methods. A new tooth profile modification is proposed for reducing vibration and noise of involute gears. The method is based on the use of cubic spline curves. The tooth profile is constrained to assume an involute shape during the loaded operation. Thus the new gear profile assures conjugate motion at all points along the line of action. The new profile is found to result in a more uniform static transmission error compared to not only standard involute profile but also modificated profile therby contributing to the improvement of vibration and noise characteristics of the gear.

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Sketch-based Modification of the Cubic B-Splines for the Pen-input Displays (펜-입력 디스플레이에서의 큐빅 B-Spline의 스케치-기반 편집 방법 연구)

  • Kim, Dae-Hyun;Kim, Myoung-Jun
    • Journal of KIISE:Computer Systems and Theory
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    • v.33 no.4
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    • pp.205-215
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    • 2006
  • Pen-input displays, such as LCD tablets and tablet PCs, are already popular for its usability in CAD design, in particular. in concept design phase. We propose an intuitive B-Spline modification scheme that can be used for the CAD systems targeting for such devices. Differently from the control point based modification schemes for the B-splines, our scheme relates user pen marking to determining the final shape of the target curve and surface. This, eventually, reduces time for interacting with the shape parameters (i.e., by control points or direct manipulators), which has been regarded as an unavoidable routine tasks for design. To prove its usability, we made an experiments with selected subjects who have been working for industrial design.

A Unified Surface Modeling Technique Using a Bezier Curve Model (de Casteljau Algorithm) (베지에 곡선모델 (드 카스텔죠 알고리듬) 을 이용한 곡면 통합 모델링 기법)

  • Rhim, Joong-Hyun;Lee, Kyu-Yeul
    • Journal of the Society of Naval Architects of Korea
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    • v.34 no.4
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    • pp.127-138
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    • 1997
  • In this study, a new technique is presented, by which one can define ship hull form with full fairness from the input data of lines. For curve modeling, the de Casteljau Algorithm and Bezier control points are used to express free curves and to establish the unified curve modeling technique which enables one to convert non-uniform B-spline (NUB) curve or cubic spline curve into composite Bezier curves. For surface modeling, the mesh curve net which is required to define surface of ship hull form is interpolated by the method of the unified curve modeling, and the boundary curve segments of Gregory surface patches are generated by remeshing(rearranging) the given mesh curve net. From these boundary information, composite Gregory surfaces of good quality in fairness can be formulated.

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A continuous solution of the heat equation based on a fuzzy system

  • Moon, Byung-Soo;Hwang, In-Koo;Kwon, Kee-Choon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.3 no.1
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    • pp.13-17
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    • 2003
  • A continuous solution of the Dirichlet boundary value problem for the heat equation $u_t$$a2u_{xx}$ using a fuzzy system is described. We first apply the Crank-Nicolson method to obtain a discrete solution at the grid points for the heat equation. Then we find a continuous function to represent approximately the discrete values at the grid points in the form of a bicubic spline function (equation omitted) that can in turn be represented exactly by a fuzzy system. We show that the computed values at non-grid points using the bicubic spline function is much smaller than the ones obtained by linear interpolations of the values at the grid points. We also show that the fuzzy rule table in the fuzzy system representation of the bicubic spline function can be viewed as a gray scale image. Hence, the fuzzy rules provide a visual representation of the functions of two variables where the contours of different levels for the function are shown in different gray scale levels

Vibration of antisymmetric angle-ply laminated plates under higher order shear theory

  • Javed, Saira;Viswanathan, K.K.;Aziz, Z.A.;Karthik, K.;Lee, J.H.
    • Steel and Composite Structures
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    • v.22 no.6
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    • pp.1281-1299
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    • 2016
  • This paper deals with the analysis of vibration of antisymmetric angle-ply plates using spline method for higher order shear theory. Free vibration of laminated plates is addressed to show the capability of the present method in the vicinity of higher order shear deformation theory and simply supported edges of plates. The coupled differential equations are obtained in terms displacement and rotational functions. These displacement and rotational functions are approximated using cubic and quantic spline. A generalized eigenvalue problem is obtained and solved numerically for an eigenfrequency parameter and an associated eigenvector of spline coefficients. The antisymmetric angle-ply fiber orientation are taken as design variables. Numerical results enable us to examine the frequencies for various geometric and material parameters and accuracy and effectiveness of the proposed method is also verified by comparative study.

Performance Improvement of Material Recognition Sensor Using Cubic Spline Interpolation (Spline보간식을 이용한 물체재질인식센서의 성능개선)

  • Park, J.G.;Lim, Y.C.;Cho, K.Y.;Kim, Y.G,;Chang, Y.H.
    • Journal of Sensor Science and Technology
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    • v.1 no.1
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    • pp.43-51
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    • 1992
  • This paper describes a noble robot sensor designed to recognize an unknown material by measuring its thermal conductivity on various ambient temperature. The excellent agreement has been obtained between the measured sensor temperature and the calculated sensor temperature by cubic spline interpolation. The active sensor to measure the thermal conductivity of a gripped object was designed and the software program using C language to discriminate objects made of different materials was developed. The temperature response characteristics of different materials on the same ambient temperature was investigated. The temperatures on three comparing points varied linearly and had parallel relation with one another in accordance with various ambient temperature.

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Estimation of Uncertain Past and Future Locations of Moving objects (이동 객체의 불확실한 과거 및 미래의 위치 추정)

  • 안윤애;류근호
    • Journal of KIISE:Databases
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    • v.29 no.6
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    • pp.441-452
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    • 2002
  • If continuous moving objects are managed by conventional database, it is not possible for them to store all position information changed over time in the database. Therefore, a time period of regular rate is determined and position information of moving objects are discretely stored in the system for every time period. However, if continuous moving objects are managed as discrete model, we will have problems which cannot properly answer to the query about uncertain past or future position information. To solve this problem, in this paper, we propose the method and algorithm which use the history information stored in the same database, to estimate the past or future location of moving objects. The cubic spline interpolation is used to estimate the past location and the mean movement value of the history information is used to predict the future location of moving objects. Finally, from the location estimation experimentation of using virtual trajectory and location sample, we proved that the proposed cubic spline function has less error than the linear function.