• Title/Summary/Keyword: Spline curve

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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.

Color Transfer using Color Contrast Based Templates (색의대비 기반 템플릿을 이용한 색상 변환)

  • Park, Young-Sup;Yoon, Kyung-Hyun;Lee, Eun-Seok
    • Journal of Korea Multimedia Society
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    • v.12 no.5
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    • pp.633-643
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    • 2009
  • We propose a color transfer method that used color contrast based templates to express the visual difference clearly between objects, while remaining the quality of the input image. Our algorithm employs colors of both the input image and template distributed on the $a^{\ast}b^{\ast}$chrominance plane of CIE $L^{\ast}a^{\ast}b^{\ast}$color space. The templates are made by considering the effect of color contrast and have the shape of either a line or a curve represented color distribution of the basic colors based gradation image. These tempates can be modeled on spline curves. We also generate simply new templates with the different basic colors by moving the control points of that curve. The color transfer method using the templates is done through a regressive analysis and color matching. We maintained color coherence of the input image by transforming similarly the color distribution of an input image to the one of templates.

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Beam on Elasto-Plastic Foundation Modeling of Tieback Walls (앵커토류벽의 탄소성보 해석에 관한 연구)

  • 김낙경
    • Geotechnical Engineering
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    • v.14 no.6
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    • pp.81-92
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    • 1998
  • A beam on elasto-plastic foundation modeling of soldier pile and woodlagging tieback walls or anchored walls was developed and tested. An instrumented full scale tieback wall in sand was constructed at the National Geotechnical Experimentation Bite located on Texas A&M University. The experimental earth pressure deflection relationship (p-y curves) was developed from the measurements. The construction sequence was simulated in the proposed method. The conceptual methodology of an anchored wall design was introduced by using the proposed method. The proposed method was evaluated with the measurements of case histories in sand and clay. A parametric research was performed to study the most influencing factors for the proposed method. It is concluded that the proposed method represents a significant improvement on the prediction of bending moments and deflections of the properly designed walls.

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Numerical simulation of fully nonlinear sloshing waves in three-dimensional tank under random excitation

  • Xu, Gang;Hamouda, A.M.S.;Khoo, B.C.
    • Ocean Systems Engineering
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    • v.1 no.4
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    • pp.355-372
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    • 2011
  • Based on the fully nonlinear velocity potential theory, the liquid sloshing in a three dimensional tank under random excitation is studied. The governing Laplace equation with fully nonlinear boundary conditions on the moving free surface is solved using the indirect desingularized boundary integral equation method (DBIEM). The fourth-order predictor-corrector Adams-Bashforth-Moulton scheme (ABM4) and mixed Eulerian-Lagrangian (MEL) method are used for the time-stepping integration of the free surface boundary conditions. A smoothing scheme, B-spline curve, is applied to both the longitudinal and transverse directions of the tank to eliminate the possible saw-tooth instabilities. When the tank is undergoing one dimensional regular motion of small amplitude, the calculated results are found to be in very good agreement with linear analytical solution. In the simulation, the normal standing waves, travelling waves and bores are observed. The extensive calculation has been made for the tank undergoing specified random oscillation. The nonlinear effect of random sloshing wave is studied and the effect of peak frequency used for the generation of random oscillation is investigated. It is found that, even as the peak value of spectrum for oscillation becomes smaller, the maximum wave elevation on the side wall becomes bigger when the peak frequency is closer to the natural frequency.

Physical Properties Analysis of Mango using Computer Vision

  • Yimyam, Panitnat;Chalidabhongse, Thanarat;Sirisomboon, Panmanas;Boonmung, Suwanee
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.746-750
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    • 2005
  • This paper describes image processing techniques that can detect, segment, and analyze the mango's physical properties such as size, shape, surface area, and color from images. First, images of mangoes taken by a digital camera are analyzed and segmented. The segmentation is done based on constructed hue model of the sample mangoes. Some morphological and filtering techniques are then applied to clean noises before fitting spline curve on the mango boundary. From the clean segmented image, the mango projected area can be computed. The shape of the mango is then analyzed using some structuring models. Color is also spatially analyzed and indexed in the database for future classification. To obtain the surface area, the mango is peeled. The scanned image of its peels is then segmented and filtered using similar approach. With calibration parameters, the surface area could then be computed. We employed the system to evaluate physical properties of a mango cultivar called "Nam Dokmai". There were sixty mango samples in three various sizes graded by an experienced farmer's eyes and hands. The results show the techniques could be a good alternative and more feasible method for grading mango comparing to human's manual grading.

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Tear Extraction from Ultrasonic Images of Shoulder using Fuzzy Stretching and SOM Based Quantization (퍼지 스트레칭과 SOM 기반 양자화를 이용한 어깨 초음파 영상에서의 인대 손상 영역 추출)

  • Kim, Yoon-Ho;Kim, Min-Ha;Song, Yu-Seon;Kim, Kwang-Beak
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2017.01a
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    • pp.9-12
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    • 2017
  • 본 논문에서는 어깨 초음파 영상을 분석하여 인대 손상(Tear) 영역을 추출하는 방법을 제안한다. 제안된 방법은 초음파 영상에서 ROI(Region of Interest) 영역을 추출하고 추출된 ROI 영역에서 사다리꼴 형태의 소속 함수를 적용한 퍼지 스트레칭 기법을 이용하여 명암 대비를 높인다. 명암 대비가 조정된 ROI 영역에서 밝기 평균 이진화 기법을 적용하여 ROI 영역을 이진화한다. 이진화가 적용된 ROI 영역에서 워터쉐드 기법을 적용하여 연골과 힘줄의 후보 영역들을 추출한다. 추출된 연골과 힘줄의 후보 영역들 중에서 위에서 아래로 스캔하여 수평 너비가 가장 큰 영역에 해당하는 힘줄 영역의 상단 경계선을 추출한다. 그리고 아래에서 위로 스캔하여 수평 너비가 가장 큰 영역의 상단 경계에 스플라인 곡선을 적용하여 연골 영역의 상단 경계선을 추출한다. 힘줄 영역의 상단 경계선과 연골 영역의 상단 경계선 양 끝에 2차 함수 곡선을 적용하여 곡선 사이의 양자화할 영역을 추출한 후, SOM 기법을 적용하여 인대 손상 후보 영역을 양자화한다. 양자화된 인대 손상 후보 영역을 분석하여 어깨 힘줄의 손상 영역과 비손상 영역을 구분하고 인대 손상(Tear) 영역을 추출한다. 제안된 방법을 어깨 힘줄이 있는 초음파 영상을 대상으로 실험한 결과, 인대 손상(Tear) 영역이 비교적 정확히 추출되었다.

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Real-Time Tool-Path Generation for 3-Axis CNC Machining of NURBS Surfaces (NURBS 곡면의 3축 CNC 가공을 위한 실시간 공구경로 생성)

  • Koo, Tae-Hoon;Jee, Sung-Chul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.8
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    • pp.1418-1425
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    • 2003
  • In CAD systems, a surface to be machined is expressed by a series of curves, such as B-spline, Bezier and NURBS curves, which compose the surface and then in CAM systems the curves are divided into a large number of line or arc segments. These divided movement commands, however, cause many problems including their excessive size of NC data that makes almost impossible local adjustment or modification of the surface. To cope with those problems, the necessity of real-time curve or surface interpolators was embossed. This paper presents an efficient real-time tool-path generation method fur interpolation of NURBS surfaces in CNC machining. The proposed tool-path generation method is based on an improved iso-scallop strategy and can provide better precision than the existing methods. The proposed method is designed such that tool-path planning is easily managed in real-time. It proposed a new algorithm for regulation of a scallop height, which can efficiently generate tool-paths and can save machining time compared with the existing method. Through computer simulations, the performance of the proposed method is analyzed and compared with the existing method in terms of federate, total machining time and a degree of constraint on the scallop height.

A Pilot Project to Measure Propagated Error in Buffering Process (버퍼링 과정에서의 오차전파 측정을 위한 선험 프로젝트 수행)

  • Yu, Ki-Yun
    • Journal of Korean Society for Geospatial Information Science
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    • v.9 no.2 s.18
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    • pp.17-27
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    • 2001
  • Buffering is one of the popular spatial analytical functions widely used in many proximity analyses. The buffeting inevitably entails a new polygon of specified edge that is simulated by rolling a ball around the buffering object. While buffering, the error on the buffering object propagates to the new buffered object. In this paper the error propagation behavior during the buffering operation is analyzed based on a pilot project for two different data models: polyline and spline curve. Thus, the error on the buffered objects are classified, mathematically defined, and measured. For measurements, the pilot project is designed and performed using a test site that is a lake boundary at Wisconsin, USA.

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Rendering of Sweep Surfaces using Programmable Graphics Hardware (그래픽스 하드웨어를 이용한 스윕 곡면의 렌더링)

  • Ko, Dae-Hyun;Yoon, Seung-Hyun;Lee, Ji-Eun
    • Journal of the Korea Computer Graphics Society
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    • v.16 no.4
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    • pp.11-16
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    • 2010
  • We present an efficient algorithm for rendering sweep surfaces using programmable graphics hardware. A sweep surface can be represented by a cross-section curve undergoing a spline motion. This representation has a simple matrix-vector multiplication structure that can easily be adapted to programmable graphics hardware. The data for the motion and cross-section curves are stored in texture memory. The vertex processor considers a pair of surface parameters as a vertex and evaluates its coordinates and normal vector with a single matrix multiplication. Using the GPU in this way is between 10 and 40 times as fast as CPU-based rendering.

Model Fitting using an Active Surface with Global Detormations (전역 변형을 갖는 활성곡면을 사용한 모델 적합)

  • Kim, Dong-Geun;Choe, Jeung-Won;Hwang, Chi-Jeong
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.3
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    • pp.792-801
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    • 1997
  • In this paper we propose an algorithm which fits a surface to noise-corrupted data points using an aceive sur-vace with global deformations.It is 3-dimensional surface extension of our precious works on 2-dimensional curve modell[11,12].We use fimite differences,and represent shapes of surface as global transfromation suring evolution based on the ballon [odel[2,3]which allows partial inflation or deflation by using niegborhood'sextermal foreces on each node points.At first,we make local deformations based on the balloon [odel,and then the blobal transformation from the surface before deformations to the defomed surface is calcualted by the deterministic lest squre method,finally we apply the global transformation to the surface before deformations.In experiments we fit a surface(elliposid,B-spline)to noise-corrupted 3D data points using the active surface with affine deformations.

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