• Title/Summary/Keyword: least squares fitting

Search Result 143, Processing Time 0.024 seconds

Finite Step Method for the Constrained Optimization Problem in Phase Contrast Microscopic Image Restoration

  • Adiya, Enkhbolor;Yadam, Bazarsad;Choi, Heung-Kook
    • Journal of Multimedia Information System
    • /
    • v.1 no.1
    • /
    • pp.87-93
    • /
    • 2014
  • The aim of microscopic image restoration is to recover the image by applying the inverse process of degradation, and the results facilitate automated and improved analysis of the image. In this work, we consider the problem of image restoration as a minimization problem of convex cost function, which consists of a least-squares fitting term and regularization terms with non-negative constraints. The finite step method is proposed to solve this constrained convex optimization problem. We demonstrate the convergence of this method. Efficiency and restoration capability of the proposed method were tested and illustrated through numerical experiments.

  • PDF

A Graphical Method for Evaluating the Effect of Blocking in Response surface Designs Using Cuboidal Regions

  • Sang-Hyun Park;Dae-Heung Jang
    • Communications for Statistical Applications and Methods
    • /
    • v.5 no.3
    • /
    • pp.607-621
    • /
    • 1998
  • When fitting a response surface model, the least squares estimates of the model's parameters and the prediction variance will generally depend on how the response surface design is blocked. That is, the choice of a blocking arrangement for a response surface design can have a considerable effect on estimating the mean response and on the size of the prediction variance even if the experimental runs are the same. Therefore, care should be exercised in the selection of blocks. In this paper, we prognose a graphical method for evaluating the effect of blocking in a response surface designs using cuboidal regions in the presence of a fixed block effect. This graphical method can be used to investigate how the blocking has influence on the prediction variance throughout the entire experimental region of interest when this region is cuboidal, and compare the block effect in the cases of the orthogonal and non-orthogonalblockdesigns, resfectively.

  • PDF

An alternative method for estimation of annual extreme wind speeds

  • Hui, Yi;Yang, Qingshan;Li, Zhengnong
    • Wind and Structures
    • /
    • v.19 no.2
    • /
    • pp.169-184
    • /
    • 2014
  • This paper presents a method of estimation of extreme wind. Assuming the extreme wind follows the Gumbel distribution, it is modeled through fitting an exponential function to the numbers of storms over different thresholds. The comparison between the estimated results with the Improved Method of Independent Storms (IMIS) shows that the proposed method gives reliable estimation of extreme wind. The proposed method also shows its advantage on the insensitiveness of estimated results to the precision of the data. The volume of extreme storms used in the estimation leads to more than 5% differences in the estimated wind speed with 50-year return period. The annual rate of independent storms is not a significant factor to the estimation.

The Three Dimensional Modeling Method of Structure in Urban Areas using Airborne Multi-sensor Data (다중센서 데이터를 이용한 구조물의 3차원 모델링)

  • Son, Ho-Woong;Kim, Ki-Young;Kim, Young-Kyung
    • Journal of the Korean Geophysical Society
    • /
    • v.9 no.1
    • /
    • pp.7-19
    • /
    • 2006
  • Laser scanning is a new technology for obtaining Digital Surface Models(DSM) of the earth surface.It is a fast method for sampling the earth surface with high density and high point accuracy. This paper is for buildings extraction from LiDAR points data. The core part of building construction is based on a parameters filter for distinguishing between terrain and non-terrain laser points. The 3D geometrical properties of the building facades are obtained based on plane fitting using least-squares adjustment. The reconstruction part of the procedure is based on the adjacency among the roof facades. Primitive extraction and facade intersections are used for building reconstruction. For overcome the difficulty just reconstruct of laser points data used with digital camera images. Also, 3D buildings of city area reconstructed using digital map. Finally, In this paper show 3D building Modeling using digital map and LiDAR data.

  • PDF

Object Recognition-based Global Localization for Mobile Robots (이동로봇의 물체인식 기반 전역적 자기위치 추정)

  • Park, Soon-Yyong;Park, Mignon;Park, Sung-Kee
    • The Journal of Korea Robotics Society
    • /
    • v.3 no.1
    • /
    • pp.33-41
    • /
    • 2008
  • Based on object recognition technology, we present a new global localization method for robot navigation. For doing this, we model any indoor environment using the following visual cues with a stereo camera; view-based image features for object recognition and those 3D positions for object pose estimation. Also, we use the depth information at the horizontal centerline in image where optical axis passes through, which is similar to the data of the 2D laser range finder. Therefore, we can build a hybrid local node for a topological map that is composed of an indoor environment metric map and an object location map. Based on such modeling, we suggest a coarse-to-fine strategy for estimating the global localization of a mobile robot. The coarse pose is obtained by means of object recognition and SVD based least-squares fitting, and then its refined pose is estimated with a particle filtering algorithm. With real experiments, we show that the proposed method can be an effective vision- based global localization algorithm.

  • PDF

Pointwise Estimation of Density of Heteroscedastistic Response in Regression

  • Hyun, Ji-Hoon;Kim, Si-Won;Lee, Sung-Dong;Byun, Wook-Jae;Son, Mi-Kyoung;Kim, Choong-Rak
    • The Korean Journal of Applied Statistics
    • /
    • v.25 no.1
    • /
    • pp.197-203
    • /
    • 2012
  • In fitting a regression model, we often encounter data sets which do not follow Gaussian distribution and/or do not have equal variance. In this case estimation of the conditional density of a response variable at a given design point is hardly solved by a standard least squares method. To solve this problem, we propose a simple method to estimate the distribution of the fitted vales under heteroscedasticity using the idea of quantile regression and the histogram techniques. Application of this method to a real data sets is given.

Estimation of Real Boundary with Subpixel Accuracy in Digital Imagery (디지털 영상에서 부화소 정밀도의 실제 경계 추정)

  • Kim, Tae-Hyeon;Moon, Young-Shik;Han, Chang-Soo
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.16 no.8
    • /
    • pp.16-22
    • /
    • 1999
  • In this paper, an efficient algorithm for estimating real edge locations to subpixel values is described. Digital images are acquired by projection into image plane and sampling process. However, most of real edge locations are lost in this process, which causes low measurement accuracy. For accurate measurement, we propose an algorithm which estimates the real boundary between two adjacent pixels in digital imagery, with subpixel accuracy. We first define 1D edge operator based on the moment invariant. To extend it to 2D data, the edge orientation of each pixel is estimated by the LSE(Least Squares Error)line/circle fitting of a set of pixels around edge boundary. Then, using the pixels along the line perpendicular to the estimated edge orientation the real boundary is calculated with subpixel accuracy. Experimental results using real images show that the proposed method is robust in local noise, while maintaining low measurement error.

  • PDF

Quadratic polynomial fitting algorithm for peak point detection of white light scanning interferograms (백색광주사간섭무늬의 정점검출을 위한 이차다항식맞춤 알고리즘)

  • 박민철;김승우
    • Korean Journal of Optics and Photonics
    • /
    • v.9 no.4
    • /
    • pp.245-250
    • /
    • 1998
  • A new computational algorithm is presented for the peak point detection of white light interferograms. Assuming the visibility function of white light interferograms as a quadratic polynomial, the peak point is searched so as to minimize the error sum between the measured intensity data and the analytical intensity. As compared with other existing algorithms, this new algorithm requires less computation since the peak point is simply determined with a single step matrix multiplication. In addition, a good robustness is obtained against external random disturbances on measured intensities since the algorithm is based upon least squares principles.

  • PDF

Application of the Gradient-Based 3D Patch Extraction Method to Terrain and Man-made Objects for Construction of 3D CyberCity (3차원 사이버도시구축을 위한 그래디언트기반 3차원 평면추출기법의 지형 및 인공지물지역에의 적용에 관한 연구)

  • Seo, Su-Young
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
    • /
    • 2010.04a
    • /
    • pp.227-229
    • /
    • 2010
  • This study presents an application of the 3D patch extraction method which is based on gradient-driven properties to obtain 3D planar patches over the terrain and man-made objects from lidar data. The method which was exploited in this study is composed of a sequence of processes: segmentation by slope, initiation of triggering patches by mode selection, and expansion of the triggering patches. Since urban areas contain many planar regions over the terrain surface, application of the method has been experimented to extract 3D planar patches not only from non-terrain objects but also from the terrain. The experimental result shows that the method is efficient to acquire 3D planar patches.

  • PDF

DESIGN OF ADAPTIVE CONTROLLER OF DC SERVO MOTOR (직류전동기의 적응 제어기 설계에 관한 연구)

  • Chang, S.G.;Won, J.S.
    • Proceedings of the KIEE Conference
    • /
    • 1987.11a
    • /
    • pp.25-28
    • /
    • 1987
  • Design procedure of adaptive controller with variable load condition is present and applied to velocity control of small, permanent magnet DC servo motor. The state feedback control scheme is adopted and Recursive Least Squares algorithm is used for parameter estimation. In order to reduce the time consuming. In the procedure of adaptation-gain tuning of state feedback controller, approximate curve fitting technique is applied to the relations between load condition and poles of the system, load condition and feedback gains. With this method, fast adaptation can be accomplished. It is shown that this procedure can be applied not only to variable load condition but also to variation of other system constants, for example variation of resistance and inductance etc.. Simulation results is present for both cases - variable inertia load, variable motor resistance to verify performance improvements. This design procedure produces an adaptive con troller which is feasible for implementation with microprocessor by reducing calculation time.

  • PDF