• 제목/요약/키워드: least squares fitting

검색결과 143건 처리시간 0.025초

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
    • /
    • 제1권1호
    • /
    • 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
    • /
    • 제5권3호
    • /
    • 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
    • /
    • 제19권2호
    • /
    • 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.

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

  • 손호웅;김기영;김영경
    • 지구물리
    • /
    • 제9권1호
    • /
    • 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

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

  • 박순용;박민용;박성기
    • 로봇학회논문지
    • /
    • 제3권1호
    • /
    • 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
    • 응용통계연구
    • /
    • 제25권1호
    • /
    • 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.

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

  • 김태현;문영식;한창수
    • 한국정밀공학회지
    • /
    • 제16권8호
    • /
    • 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

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

  • 박민철;김승우
    • 한국광학회지
    • /
    • 제9권4호
    • /
    • pp.245-250
    • /
    • 1998
  • 본 논문에서는 백색광주사간섭무늬의 정점검출을 위한 새로운 디지털처리 알고리즘을 제안한다. 본 알고리즘은 백색광주사간섭무늬의 가시도함수를 이차의 다항식으로 가정하고, 측정된 광강도 값들을 최소자승법을 이용하여 직접적으로 곡선맞춤하여 가시도함수의 정점의 위치를 검출한다. 기존의 정점검출 알고리즘들과 비교하여, 본 이차다항식맞춤 알고리즘은 가시도함수의 추출을 위한 별도의 연산이 요구되지 않아 3N+29의 작은 곱셈 계산량만으로 연산을 완료 할 수 있다. 또한 최소자승법을 사용함으로써 간섭무늬가 갖는 외부 교란을 효과적으로 억제하여 안정된 해를 제공하는 장점을 갖는다.

  • PDF

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

  • 서수영
    • 한국측량학회:학술대회논문집
    • /
    • 한국측량학회 2010년 춘계학술발표회 논문집
    • /
    • 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

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

  • 장서건;원종수
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
    • /
    • 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