• Title/Summary/Keyword: Cubic spline method

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A Baseline Correction for Effective Analysis of Alzheimer’s Disease based on Raman Spectra from Platelet (혈소판 라만 스펙트럼의 효율적인 분석을 위한 기준선 보정 방법)

  • Park, Aa-Ron;Baek, Sung-June
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.49 no.1
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    • pp.16-22
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    • 2012
  • In this paper, we proposed a method of baseline correction for analysis of Raman spectra of platelets from Alzheimer's disease (AD) transgenic mice. Measured Raman spectra include the meaningful information and unnecessary noise which is composed of baseline and additive noise. The Raman spectrum is divided into the local region including several peaks and the spectrum of the region is modeled by curve fitting using Gaussian model. The additive noise is clearly removed from the process of replacing the original spectrum with the fitted model. The baseline correction after interpolating the local minima of the fitted model with linear, piecewise cubic Hermite and cubic spline algorithm. The baseline corrected models extract the feature with principal component analysis (PCA). The classification result of support vector machine (SVM) and maximum $a$ posteriori probability (MAP) using linear interpolation method showed the good performance about overall number of principal components, especially SVM gave the best performance which is about 97.3% true classification average rate in case of piecewise cubic Hermite algorithm and 5 principal components. In addition, it confirmed that the proposed baseline correction method compared with the previous research result could be effectively applied in the analysis of the Raman spectra of platelet.

Two-Dimensional Flow Behavior Through a Stage of an Axial Compressor (축류 압축기내의 2차원 유동 특성)

  • Hong, Seong-Hun;Baek, Je-Hyeon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.8
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    • pp.2561-2571
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    • 1996
  • The flow in the turbomachinery is very unsteady due to the stator-rotor interaction. It has been indicated that the stator-rotor interaction has three distinct causes of unsteadiness: that is, the viscous vortex shedding, wake rotor interaction and potential stator-rotor interaction. In this paper, the mechanism of unsteady potential interaction and wake interaction in the stator-rotor stage flow is numerically investigated in two-dimensional view point. The numerical technique used is the upwind scheme of Van Leer's Flux Vector Splitting(FVS) and cubic spline interpolation is applied on zonal interface. Then, the flow field of a compressor stage composed of NACA 65410 is analyzed. Flow fields are found to be simulated reasonably by this method and the sensitivity due to back-pressure variation is more stronger than rotor-velocity variation.

Dynamic Gait embody using angular acceleration for a Walking Robot (각가속도를 이용한 이족 로봇의 동적 걸음새 구현)

  • Park, Jae-Mun;Park, Seung-Yub;Ko, Bong-Jin
    • Journal of Advanced Navigation Technology
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    • v.11 no.2
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    • pp.209-216
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    • 2007
  • In this paper, we embodied posture-stabilization and dynamic gait in a walking robot. 10 RC servo motors are used to operate joints. And the joints have enough moving ranges suitable in any walking pattern. Each joint trajectory is generated by cubic spline interpolation method and the stability of the trajectory is verified by using Zero Moment Point from the robot modeling. To avoid complex structure and expression, Zero Moment Point of the biped robot used angular acceleration is suggested. To measure the stability of the biped robot, Tilt sensor and gyro sensor are used. Finally, Personal Computer is used computer monitoring and data processing. Most of computation, such as 10 RC servo motor control, joint trajectory generating, ZMP compensation, sense measuring, etc, was used Digital Signal Processor.

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Non-rigid Image Registration using Constrained Optimization (Constrained 최적화 기법을 이용한 Non-rigid 영상 등록)

  • Kim Jeong tae
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.10C
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    • pp.1402-1413
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    • 2004
  • In non-rigid image registration, the Jacobian determinant of the estimated deformation should be positive everywhere since physical deformations are always invertible. We propose a constrained optimization technique at ensures the positiveness of Jacobian determinant for cubic B-spline based deformation. We derived sufficient conditions for positive Jacobian determinant by bounding the differences of consecutive coefficients. The parameter set that satisfies the conditions is convex; it is the intersection of simple half spaces. We solve the optimization problem using a gradient projection method with Dykstra's cyclic projection algorithm. Analytical results, simulations and experimental results with inhale/exhale CT images with comparison to other methods are presented.

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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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

Real-time Implementation and Comparative Study on Trajectory Planning Methods for Robot Manipulators (로보트 매니퓰레이터에 대한 궤적 계획 방법들의 실시간 구현 및 상호 비교 연구)

  • Cho, Jeong-Ho;Suh, Il-Hong;Li, Joon-Hong;Yang, Hai-Won;Im, Dal-Ho
    • Proceedings of the KIEE Conference
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    • 1989.11a
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    • pp.462-466
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    • 1989
  • This paper describes the methods of spline low-order polynomial trajectory planning using only a few limited look-ahead knots on the desired trajectory for the real-time computing. Specifically presented are the mixed joint trajectory planning methods which apply linear or LSPB method to initial and finial segments, overlapped cubic spline method to the other segments, where the displacements for initial and finial segments are chosen to be relatively smaller than the displacements for the other, equidistant segments. Experimental and simulation results of these methods show smooth motions and improved path tracking performances compared with any other interpolated joint trajectory planning methods.

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Computer Simulation of Solidification in L-Sections (L형(型) 주물응고(鑄物凝固)에 대한 Computer Simulation)

  • Han, Yoon-Hee;Kim, Myung-Han;Kim, Dong-Ok
    • Journal of Korea Foundry Society
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    • v.5 no.2
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    • pp.125-136
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    • 1985
  • The most desirable method for the solution of solidification problems in castings must be the one which combines accuracy, simplicity, and low computer usage cost. The purpose of the present study is to develop a method which includes all these advantages. The purpose of the present research was approached by the introduction of two methods: (1) A pour-out test, employed with very high purity aluminum, for the purpose of obtaining accurate solidification data in L-sections; and (2) an numerical technique, using the cubic spline function for defining solidification curves.

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