• 제목/요약/키워드: point estimation

검색결과 2,116건 처리시간 0.036초

Extraction of Geometric Primitives from Point Cloud Data

  • Kim, Sung-Il;Ahn, Sung-Joon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.2010-2014
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    • 2005
  • Object detection and parameter estimation in point cloud data is a relevant subject to robotics, reverse engineering, computer vision, and sport mechanics. In this paper a software is presented for fully-automatic object detection and parameter estimation in unordered, incomplete and error-contaminated point cloud with a large number of data points. The software consists of three algorithmic modules each for object identification, point segmentation, and model fitting. The newly developed algorithms for orthogonal distance fitting (ODF) play a fundamental role in each of the three modules. The ODF algorithms estimate the model parameters by minimizing the square sum of the shortest distances between the model feature and the measurement points. Curvature analysis of the local quadric surfaces fitted to small patches of point cloud provides the necessary seed information for automatic model selection, point segmentation, and model fitting. The performance of the software on a variety of point cloud data will be demonstrated live.

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영상모델링을 이용한 표면결함검출에 관한 연구 (A Study on the Detection of Surface Defect Using Image Modeling)

  • 목종수;사승윤;김광래;유봉환
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 추계학술대회 논문집
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    • pp.444-449
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    • 1996
  • The semiconductor, which is precision product, requires many inspection processes. The surface conditions of the semiconductor chip affect on the functions of the semiconductors. The defects of the chip surface are cracks or voids. As general inspection method requires many inspection procedure, the inspection system which searches immediately and precisely the defects of the semiconductor chip surface is required. We suggest the detection algorithm for inspecting the surface defects of the semiconductor surface. The proposed algorithm first regards the semiconductor surface as random texture and point spread function, and secondly presents the character of texture by linear estimation theorem. This paper assumes that the gray level of each pixel of an image is estimated from a weighted sum of gray levels of its neighbor pixels by linear estimation theorem. The weight coefficients are determined so that the mean square error is minimized. The obtained estimation window(two-dimensional estimation window) characterizes the surface texture of semiconductor and is used to discriminate the defects of semiconductor surface.

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신경망 시스템 기반의 소프트웨어 개발노력 추정모델 구축에 관한 연구 (Software Development Effort Estimation Using Neural Network Model)

  • 백승익;김병관
    • 한국IT서비스학회지
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    • 제5권1호
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    • pp.97-109
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    • 2006
  • As software becomes more complex and its scope dramatically increases, the importance of research on developing methods for estimating software development efforts has been increased. Such accurate estimation has a prominent impact on the development projects. To develop accurate effort estimation models, many studies have been conducted among the academia and the practitioners. Out of the numerous methods, Constructive Cost Model (COCOMO) based on Line of Code (LOC), Regression Model based on Function Point (FP) were the most popular models in the past. As today's development environments are dynamically changing, these traditional methods do not work anymore. There is an impending need to develop an accurate estimation model which accommodates itself to the new environments. As a possible solution, this research proposes and evaluates an software development estimation model based on function points and neural networks.

Minimum risk point estimation of two-stage procedure for mean

  • Choi, Ki-Heon
    • Journal of the Korean Data and Information Science Society
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    • 제20권5호
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    • pp.887-894
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    • 2009
  • The two-stage minimum risk point estimation of mean, the probability of success in a sequence of Bernoulli trials, is considered for the case where loss is taken to be symmetrized relative squared error of estimation, plus a fixed cost per observation. First order asymptotic expansions are obtained for large sample properties of two-stage procedure. Monte Carlo simulation is carried out to obtain the expected sample size that minimizes the risk and to examine its finite sample behavior.

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완전디지털 자동초점 시스템 구현을 위한 부화소단위 점확산함수 추정 (Sub-pixel Point Spread function Estimation for Fully Digital Auto-Focusing System)

  • 황성현;신정호;백준기
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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    • pp.1727-1730
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    • 2003
  • In this paper we propose a sub-pixel point spread function (PSF) estimation method for a fully digital auto-focusing system. We assume that the amount of out-of-focus is the same along the concentric circle. In order to estimate the accurate PSF, sub-pixel information is considered in the proposed PSF estimation procedure. The feasibility of the proposed algorithm is experimentally demonstrated.

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Change-point Estimation with Loess of Means

  • Kim, Jae-Hee
    • Communications for Statistical Applications and Methods
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    • 제12권2호
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    • pp.349-357
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    • 2005
  • We suggest a functional technique with loess smoothing for estimating the change-point when there is one change-point in the mean model. The proposed change-point estimator is consistent. Simulation study shows a good performance of the proposed change-point estimator in comparison with other parametric or nonparametric change-point estimators.

Nonparametric Discontinuity Point Estimation in Density or Density Derivatives

  • Huh, Jib
    • Journal of the Korean Statistical Society
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    • 제31권2호
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    • pp.261-276
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    • 2002
  • Probability density or its derivatives may have a discontinuity/change point at an unknown location. We propose a method of estimating the location and the jump size of the discontinuity point based on kernel type density or density derivatives estimators with one-sided equivalent kernels. The rates of convergence of the proposed estimators are derived, and the finite-sample performances of the methods are illustrated by simulated examples.

기능점수를 이용한 소프트웨어 개발노력 추정 (Software Development Effort Estimation Using Function Point)

  • 이상운;강정호;박중양
    • 정보처리학회논문지D
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    • 제9D권4호
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    • pp.603-612
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    • 2002
  • 소프트웨어공학에서 소프트웨어 측정분야는 30년 이상 수많은 연구가 있어 왔으나 아직까지 구체적인 소프트웨어 개발노력과 비용 추정 모델이 거의 없는 실정이다. 만약 소프트웨어 개발노력과 비용을 측정하려면 소프트웨어 규모를 추정해야 한다. 소프트웨어의 규모를 측정하기 위한 많은 소프트웨어 척도가 개발되었지만 가장 일반적인 척도가 LOC(line of code)와 FPA(Function Point Analysis)이다. FPA는 소프트웨어 규모를 측정하는데 LOC를 사용할 때의 단점을 극복할 수 있는 기법이다. 본 논문은 FP(Function Point)로 측정된 소프트웨어 규모로 소프트웨어 개발노력을 추정하는 단순회귀모델을 제안한다. 실험에 사용된 데이터들은 다양한 개발환경과 개발방법을 적용한 최근의 789개 소프트웨어 개발 프로젝트들이다. 실험 데이타들에 대한 산점도를 그려 개발노력과 FP의 적합한 관계로부터 단순회귀분석 모델을 유도하였다. 또한, 다양한 소프트웨어 개발환경과 개발방법 등을 고려해 개발된 최근의 대용량 프로젝트에 대해 제안된 단순회귀분석 모델이 기존의 회귀분석 모델들보다 개발노력 추정 정확성이 월등히 좋음을 보였다.

M-Estimation Functions Induced From Minimum L$_2$ Distance Estimation

  • Pak, Ro-Jin
    • Journal of the Korean Statistical Society
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    • 제27권4호
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    • pp.507-514
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    • 1998
  • The minimum distance estimation based on the L$_2$ distance between a model density and a density estimator is studied from M-estimation point of view. We will show that how a model density and a density estimator are incorporated in order to create an M-estimation function. This method enables us to create an M-estimating function reflecting the natures of both an assumed model density and a given set of data. Some new types of M-estimation functions for estimating a location and scale parameters are introduced.

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GIS를 이용한 유역별 오염부하량 산정시스템의 개발 (Development of Pollutant Loading Estimation System using GIS)

  • 함광준;김준현;심재민
    • 환경영향평가
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    • 제14권3호
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    • pp.97-107
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    • 2005
  • The purpose of this study is to develop a system, which estimates watershed pollutant loading rate through the combination of GIS and computational mode. Also, the applicability of this study was estimated by the application of the above system for Chuncheon City. The detailed results of these studies are as follows; The pollutant loading estimation system was developed for more convenient estimation of pollutant loading rate in watershed, and the system load was minimized by the separation of estimation module for point and non-point source. This system on the basis of GIS is very economical and efficient because it can be applied to other watershed with the watershed map. System modification is not needed. The pollutant loading estimation system for point source was developed to estimate the pollutant loading rate in watershed through the extraction of the proper data from all districts and yearly data and the execution of spatial analysis which is main function of GIS. From the verification result of spatial analysis, real watershed area and the administrative districtarea extracted by spatial analysis were $1,114,893,340.15m^2$ and $1,114,878,683.68m^2$, respectively. It shows that the spatial analysis results were very exact with only 0.001% error. The pollutant loading estimation system for non-point source was developed to calculate the pollutant loading rate through the overlaying of land-use and watershed map after the construction of new land-use map using the land register database with most exact land use classification. Application result for Chuncheon City shows that the proposed system results in one percent land use error while the statistical method results in five percent. More exact nonpoint source pollutant loading was estimated from this system.