• Title/Summary/Keyword: Curve fitting technique

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Quality Inspection of Dented Capsule using Curve Fitting-based Image Segmentation

  • Kwon, Ki-Hyeon;Lee, Hyung-Bong
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.12
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    • pp.125-130
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    • 2016
  • Automatic quality inspection by computer vision can be applied and give a solution to the pharmaceutical industry field. Pharmaceutical capsule can be easily affected by flaws like dents, cracks, holes, etc. In order to solve the quality inspection problem, it is required computationally efficient image processing technique like thresholding, boundary edge detection and segmentation and some automated systems are available but they are very expensive to use. In this paper, we have developed a dented capsule image processing technique using edge-based image segmentation, TLS(Total Least Squares) curve fitting technique and adopted low cost camera module for capsule image capturing. We have tested and evaluated the accuracy, training and testing time of the classification recognition algorithms like PCA(Principal Component Analysis), ICA(Independent Component Analysis) and SVM(Support Vector Machine) to show the performance. With the result, PCA, ICA has low accuracy, but SVM has good accuracy to use for classifying the dented capsule.

Measuring Structural Vibration from Video Signal Using Curve Fitting (영상 신호에서 커브 피팅을 이용한 구조물 진동 측정)

  • Jeon, Hyeong-Seop;Choi, Young-Chul;Park, Jong-Won
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.9
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    • pp.943-949
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    • 2009
  • Many studies for measuring vibration using image signal are suggested. These methods can measure vibration of multi-points simultaneously. However, it has the disadvantage that is very sensitive to an environment. If the measured environment is not good, image signals can be measured including much background noise. So, it is difficult to obtain accurate vibration from the measured image signals. Another problem is that camera imaging has a resolution limit. Because the resolution of the camera image is relatively much lower than that of a data acquisition system, accurate measuring vibration cannot be performed. In this paper, we proposed the enhanced technique for measuring vibration using camera signal. The key word of this paper is a curve fitting. The curve fitting can exactly detect the measurement line of interested object. So, we can measure the vibration in noisy environment. Also, it can overcome the resolution limit.

Errors in Recorded Information and Calibration of a Catchment Modelling System(II) - Monitoring Calibration Approach - (기록치 오차와 유역모형의 검정(II) - 모니터링 검정방법 -)

  • Choi, Kyung Sook
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.45 no.5
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    • pp.117-125
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    • 2003
  • Since the recorded information used for operation of a catchment modelling system contain errors that influence the calibration of catchment modelling system control parameter values, the accurate estimation of these parameters is difficult. Despite these influences, existing traditional calibration approaches focus only on achieving the best "curve fitting" between simulated and recorded data, and not on generic evaluation of control parameter values. This paper introduces an Early Stopping Technique which is aimed at avoiding the procedure of curve-fitting through monitoring improvements in the objective function used for assessing the optimal parameter set. Application of this approach to the calibration of SWMM (Storm Water Management Model) on the Centennial Park catchment in Sydney, Australia is outlined. outlined.

Improvement of Accuracy in Evaluating Hue Change Time in the Hue Detection Based Transient Liquid Crystals Technique (색상 검출방식의 천이 액정법에서 색상 변화 시간 산정의 정확도 향상)

  • Shin, So-Min;Jeon, Chang-Soo;Jung, Yong-Wun;Kwak, Jae-Su
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.11
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    • pp.918-925
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    • 2007
  • In this paper, different criteria fur determining hue change time in the hue detection based transient liquid crystals technique were compared. Results showed that methods utilizing threshold of intensity or saturation gave many missing points and quality of the calculated results were strongly depends on the value of threshold. Wider bandwidth in the hue bandwidth method showed better distribution of calculated hue change time, but induced ambiguity in the hue change time. In the time-hue curve fitting method, the distribution of evaluated hue change time was smooth and reasonable, and, by the nature of curve fitting, the noise effect on the hue was successfully considered in calculating of the hue change time. Compared to other methods, it is expected that the time-hue curve fitting method would provide better and accurate hue change time in the hue detection based transient liquid crystals technique.

Measurement of Shear Modulus at Small Strains using Cone Pressuremeter Test (Cone Pressuremeter Test를 이용한 미소변형에서 전단변형계수 측정)

  • Yi, Chang-Tok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.9 no.1
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    • pp.135-145
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    • 2005
  • Geotechnical design routinely requires that in-situ strength, stiffness of the ground be determined. In the working stress conditions, the strain level in a ground experienced by existing structures and during construction is less than about 0.1%~1%. In order to analyze the deformational behavior accurately, the in-situ testing technique which provides the reliable deformational characteristics at small strains, needs to be developed. Cone pressuremeter tests were performed on the western off-shore region of korea, and analyzed using cavity expansion theory and curve fitting technique to obtain the shear modulus at small strain level of $10^{-1}%$. The value of $E_u/S_u$ ratio for the marine clay shows about 589 at the small strain. However the value of $E_u/S_u$ estimated by lab tests are much smaller values ranged from 81 to 91. It is indicated that the curve fitting technique from CPM tests results can be used to obtain the shear modulus at small strain.

Determination of Undrained Shear Strength In Clay from Cone Pressuremeter Test (Cone Pressuremeter를 이용한 점성토의 전단 강도 산정)

  • 이장덕
    • Journal of the Korean Geotechnical Society
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    • v.20 no.8
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    • pp.49-58
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    • 2004
  • The cone pressuremeter test (CPM) is a new in-situ test which combines a standard cone penetration test with a pressuremeter. The cone pressuremeter tests in clay are presented and analyzed. An analytical solution of CPM incorporated non-linear soil behavior with no volume change is presented, and curve fitting technique is proposed to make use of both the loading and unloading portions of the pressuremeter test. The proposed method is accomplished by putting greater emphasis on the unloading portion. Twenty CPM tests are analyzed using the proposed method, and the derived undrained shear strength of soil is compared with other tests such as field vane tests and laboratory tests. The interpreted soil parameters had resonable values when compared to other in-situ and laboratory test results. The cone pressuremeter has provided reliable measures of undrained shear strength using curve fitting method.

The Derivation of Rating Curve using GRNNM and GA (GRNNM과 GA를 이용한 Rating Curve의 유도)

  • Kim, Seong-Won
    • Proceedings of the Korea Water Resources Association Conference
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    • 2005.05b
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    • pp.679-683
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    • 2005
  • The technique which connects Generalized Regression Neural Networks Model(GRNNM) with Genetic Algorithm (CA) is used to derive rating curve in the river basin. GRNNM architecture consists of 4 layers ; input, hidden, summation and output layer. GA method is applied to estimate the optimal smoothing factor when GRNNM is trained. The derivation of rating curve using GRNNM is considered different kinds of hydraulic characteristics such as water stage, area and mean velocity and is applied two stage stations; Sunsan and Jungam. Furthermore, it is compared with conventional curve-fitting method. Through the training and validation performance, the results show that GRNNM is much superior as compared to the conventional curve-fitting method.

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Experimental Vibration Analysis for Viscoelastically Damped Circular Cylindrical Shell Using Nonlinear Least Square Method (비선형 최소제곱법을 이용한 점탄성 감쇠를 갖는 원통셀의 실험진동해석)

  • Min, Cheon-Hong;Park, Han-Il;Bae, Soo-Ryong
    • Journal of Ocean Engineering and Technology
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    • v.22 no.3
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    • pp.41-46
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    • 2008
  • It is a recent trend for advanced ships and submarines to incorporate composite structures with viscoelastically damping material. Much research has been done on curve-fitting techniquesto identify vibration characteristic parameters such as natural frequencies, modal damping ratios, and mode shapes of the composite structure. In this study, an advanced technique for accurately determining vibration characteristic of a circular cylindrical shell-attached viscoelastically damping material is used, based on a multi-degree of freedom (MDOF) curve-fitting method. First, an initial value is obtained by using a linear least square method. Next, using the initial value, the exact modal parameters of the composite circular cylindrical shell are obtained by using a nonlinear least square method. Results show computation time is greatly decreased and accurate results are obtained by the MDOF curve-fitting method.

Study of the Measurement of Young's Modulus and Loss Factor for a Viscoelastic Damping Material Using a Multi Degree of Freedom Curve Fitting Method and RKU Equation (다자유도 곡선 맞춤법과 RKU 기법을 이용한 점탄성 감쇠재의 탄성 및 손실계수 추정방법 연구)

  • Min, Cheon-Hong;Park, Han-Il;Bae, Soo-Ryong;Jeon, Jae-Jin
    • Journal of Ocean Engineering and Technology
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    • v.25 no.1
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    • pp.67-72
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    • 2011
  • Offshore structures, such as a platform, a buoy, or a floating vessel, are exposed to several dynamic loads, and viscoelastic damping material is used to reduce the vibration of offshore structures. It is important to know the properties of viscoelastic materials because loss factor and Young's modulus of the viscoelastic damping material are dependent on frequency and temperature. In this study, an advanced technique for obtaining accurate loss factor and Young's modulus of the viscoelastic damping material is introduced based on a multi degree of freedom curve-fitting method and the RKU (Ross-Kerwin-Ungar) equations. The technique is based on a modified experimental procedure from ASTM E 756-04. Loss factor and Young's modulus of the viscoelastic damping material are measured for different temperatures by performing the test in a temperature-controlled vibration measurement room where temperature varies from 5 to 45 degrees Celsius.