• Title/Summary/Keyword: Mahalanobis

Search Result 182, Processing Time 0.025 seconds

On Assessing Inter-observer Agreement Independent of Variables' Measuring Units

  • Um, Yong-Hwan
    • Journal of the Korean Data and Information Science Society
    • /
    • v.17 no.2
    • /
    • pp.529-536
    • /
    • 2006
  • Investigators use either Euclidean distance or volume of a simplex defined composed of data points as agreement index to measure chance-corrected agreement among observers for multivariate interval data. The agreement coefficient proposed by Um(2004) is based on a volume of a simplex and does not depend on the variables' measuring units. We consider a comparison of Um(2004)'s agreement coefficient with others based on two unit-free distance measures, Pearson distance and Mahalanobis distance. Comparison among them is made using hypothetical data set.

  • PDF

VISIBLE/NEAR-IR REFLECTANCE SPECTROSCOPY FOR THE CLASSIFICATION OF POULTRY CARCASSES

  • Chen, Yud-Ren
    • Proceedings of the Korean Society for Agricultural Machinery Conference
    • /
    • 1993.10a
    • /
    • pp.403-412
    • /
    • 1993
  • This paper presents the progress of the development of a nondestructive technique for the classification of normal, septicemic , and cadaver poultry carcasses by the Instrumentation and Sensing Laboratory at Beltsville, Maryland, U.S.A. The Sensing technique is based on the diffuse reflectance spectroscopy of poultry carcasses.

  • PDF

Permutation tests for the multivariate data

  • Park, Hyo-Il;Kim, Ju-Sung
    • Journal of the Korean Data and Information Science Society
    • /
    • v.18 no.4
    • /
    • pp.1145-1155
    • /
    • 2007
  • In this paper, we consider the permutation tests for the multivariate data under the two-sample problem setting. We review some testing procedures, which are parametric and nonparametric and compare them with the permutation ones. Then we consider to try to apply the permutation tests to the multivariate data having the continuous and discrete components together by choosing some suitable combining function through the partial testing. Finally we discuss more aspects for the permutation tests as concluding remarks.

  • PDF

Face Detction Using Face Geometry (얼굴 기하에 기반한 얼굴 검출 알고리듬)

  • 류세진;은승엽
    • Proceedings of the IEEK Conference
    • /
    • 2002.06d
    • /
    • pp.49-52
    • /
    • 2002
  • This paper presents a fast algorithm for face detection from color images on internet. We use Mahalanobis distance between standard skin color and actual pixel color on IQ color space to segment skin color regions. The skin color regions are the candidate face region. Further, the locations of eyes and mouth regions are found by computing average pixel values on horizontal and vertical pixel lines. The geometry of mouth and eye locations is compared to the standard face geometry to eliminate false face regions. Our Method is simple and fast so that it can be applied to face search engine for internet.

  • PDF

A Study on a Optical Feature Extraction using Radon Transform (Radon 변환을 이용한 광학적 특징 추출에 관한 연구)

  • Pan, J.K.;Kwon, W.H.;Park, H.K.
    • Proceedings of the KIEE Conference
    • /
    • 1987.07a
    • /
    • pp.86-89
    • /
    • 1987
  • In this paper, feature vectors composed of 6 features of Fourier spectrum of 2-D image at each projection angle and 7 features of invariant moments are defined. The feature are extracted by optical Fourier transformer and Radon transformer. After extracting the feature, the input pattern is recognized using the squared Mahalanobis distance.

  • PDF

Vowels(a,e,i,o,u) Analysis Using Optical Flow (Optical Flow를 이용한 단모음(아,에,이,오,우) 분석)

  • 이미애;박기수
    • Proceedings of the Korea Multimedia Society Conference
    • /
    • 2002.05c
    • /
    • pp.299-302
    • /
    • 2002
  • 컴퓨터를 이용한 독순 연구는 Man Machine Interface, 지적부호화에 있어서의 송신측 기술, 청각 장애인의 독순 훈련 시스템 등 다방면에서 그 응용이 기대된다. 본 논문은, 움직임 정보는 입술의 에지영역에 집중하고 있음에 주목하여, 입술 에지영역의 Optical Flow 추정값을 독순정보로 이용하는 방법을 제안한다. 휘도값을 갖지 않는 에지에, 선형 가상 휘도값를 정해주어 Optical Flow를 추정하는 VGM을 도입해 특징 파라미터를 계산하고, 마할라노비스 평방거리(Mahalanobis's square distance)에 기초한 최대우도판별함수를 이용하여 단모음을 분석하는 알고리즘을 제안한다.

  • PDF

Image Restoration of Remote Sensing High Resolution Imagery Using Point-Jacobian Iterative MAP Estimation (Point-Jacobian 반복 MAP 추정을 이용한 고해상도 영상복원)

  • Lee, Sang-Hoon
    • Korean Journal of Remote Sensing
    • /
    • v.30 no.6
    • /
    • pp.817-827
    • /
    • 2014
  • In the satellite remote sensing, the operational environment of the satellite sensor causes image degradation during the image acquisition. The degradation results in noise and blurring which badly affect identification and extraction of useful information in image data. This study proposes a maximum a posteriori (MAP) estimation using Point-Jacobian iteration to restore a degraded image. The proposed method assumes a Gaussian additive noise and Markov random field of spatial continuity. The proposed method employs a neighbor window of spoke type which is composed of 8 line windows at the 8 directions, and a boundary adjacency measure of Mahalanobis square distance between center and neighbor pixels. For the evaluation of the proposed method, a pixel-wise classification was used for simulation data using various patterns similar to the structure exhibited in high resolution imagery and an unsupervised segmentation for the remotely-sensed image data of 1 mspatial resolution observed over the north area of Anyang in Korean peninsula. The experimental results imply that it can improve analytical accuracy in the application of remote sensing high resolution imagery.

An On-line Construction of Generalized RBF Networks for System Modeling (시스템 모델링을 위한 일반화된 RBF 신경회로망의 온라인 구성)

  • Kwon, Oh-Shin;Kim, Hyong-Suk;Choi, Jong-Soo
    • Journal of the Institute of Electronics Engineers of Korea CI
    • /
    • v.37 no.1
    • /
    • pp.32-42
    • /
    • 2000
  • This paper presents an on-line learning algorithm for sequential construction of generalized radial basis function networks (GRBFNs) to model nonlinear systems from empirical data. The GRBFN, an extended from of standard radial basis function (RBF) networks with constant weights, is an architecture capable of representing nonlinear systems by smoothly integrating local linear models. The proposed learning algorithm has a two-stage learning scheme that performs both structure learning and parameter learning. The structure learning stage constructs the GRBFN model using two construction criteria, based on both training error criterion and Mahalanobis distance criterion, to assign new hidden units and the linear local models for given empirical training data. In the parameter learning stage the network parameters are updated using the gradient descent rule. To evaluate the modeling performance of the proposed algorithm, simulations and their results applied to two well-known benchmarks are discussed.

  • PDF

Prognostics for Stator Windings of Water-Cooled Generator Against Water Absorption (수냉식 발전기 고정자 권선의 흡습 건전성 예지)

  • Jang, Beom Chan;Youn, Byeng D.;Kim, Hee Soo;Bae, Yong Chae
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.39 no.6
    • /
    • pp.625-629
    • /
    • 2015
  • In this study, we develop a prognostic method of assessing the stator windings of power generators against water absorption through statistical data analysis and degradation modeling. The 42 windings of the generator are divided into two groups: the absorption and normal groups. A degradation model of a winding is constructed using Fick's second law to predict the level of absorption. By analyzing data from the normal group, we can determine the distribution of the data of normal windings. The health index of a winding is estimated using the directional Mahalanobis distance (DMD) method. Finally, the probability distributions of the failure time of the windings are determined.

Studies on Representative Body Sizes and 3D Body Scan Data of Korean Adolescents (한국 청소년의 대표 인체치수 및 3D 인체형상자료에 관한 연구)

  • Choi, Seung-il
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.2
    • /
    • pp.227-232
    • /
    • 2016
  • 3D body scan data are used widely in various fields to make products and living spaces for superior human body fitness. Based on the 3D measurements of human bodies for teens in Size Korea 2013, this research provides a way of finding the representative body sizes and 3D body scan data. First, a multi-dimensional vector space consisting of many measurement items was projected onto a 2D vector space with circumference and length components via factor analysis. The representative body sizes and 3D scan data close to these values were obtained via the Mahalanobis distance in 2D space. Considering the adolescent growth pattern shown on this 2D space, males were divided into 4 age groups and females were divided into 3 age groups. Using the eigenbodies corresponding to the column vectors of the component score coefficient matrix, the representative body sizes of 13 measurement items (male) and 14 measurement items (female) for each age group were calculated. The representative body sizes and 3D scan data are very useful for modeling representative 3D human figures.