• Title/Summary/Keyword: Mahalanobis-Distance

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Permutation tests for the multivariate data

  • Park, Hyo-Il;Kim, Ju-Sung
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.4
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    • pp.1145-1155
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    • 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.

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

  • 류세진;은승엽
    • Proceedings of the IEEK Conference
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    • 2002.06d
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    • pp.49-52
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    • 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.

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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
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    • 1987.07a
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    • pp.86-89
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    • 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.

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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
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    • 2002.05c
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    • pp.299-302
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    • 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.

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A study on early faults detection of pressurizer pressure control system using MTS (MTS를 이용한 가압기 압력 제어 계통의 조기 고장 감지에 대한 연구)

  • Cha, Jae-Min;Kim, Joon-Young;Shin, Junguk;Yeom, Choongseob;Kang, Seong-Ki
    • The Korean Journal of Applied Statistics
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    • v.29 no.7
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    • pp.1385-1398
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    • 2016
  • A pressurizer is a major equipment system in a nuclear power plant (NPP) and controls the reactor cooling system pressure within the allowable range. Faults in the pressurizer can be critical to the NPP; therefore, early fault detection in the pressurizer is significant for NPP safety. This study applies Mahalanobis Taguchi system (MTS), which is one of the promising pattern classification methods, based on the Mahalanobis distance concept and Taguchi quality engineering theory to the early fault detection problem of the pressurizer pressure control system. We conducted experiments using data from full scope NPP simulator based on a pressurizer pressure transmitter faults scenario to validate the faults detection performance of MTS. As a result, MTS can rapidly detect the faults compared to conventional faults detection based on single sensor monitoring.

A Robust Method for Automatic Segmentation and Recognition of Apoptosis Cell (Apoptosis 세포의 자동화된 분할 및 인식을 위한 강인한 방법)

  • Liu, Hai-Ling;Shin, Young-Suk
    • Journal of KIISE:Computing Practices and Letters
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    • v.15 no.6
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    • pp.464-468
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    • 2009
  • In this paper we propose an image-based approach, which is different from the traditional flow cytometric method to detect shape of apoptosis cells. This method can overcome the defects of cytometry and give precise recognition of apoptosis cells. In this work K-means clustering was used to do the rough segmentation and an active contour model, called 'snake' was used to do the precise edge detection. And then some features were extracted including physical feature, shape descriptor and texture features of the apoptosis cells. Finally a Mahalanobis distance classifier classifies the segmentation images as apoptosis and non-apoptosis cell.

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
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    • v.39 no.6
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    • pp.625-629
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    • 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
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    • v.17 no.2
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    • pp.227-232
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    • 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.

Design of a Real-time Algorithm Using Block-DCT for the Recognition of Speed Limit Signs (Block-DCT를 이용한 속도 제한 표지판 실시간 인식 알고리듬의 설계)

  • Han, Seung-Wha;Cho, Han-Min;Kim, Kwang-Soo;Hwang, Sun-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.12B
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    • pp.1574-1585
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    • 2011
  • This paper proposes a real-time algorithm for speed limit sign recognition for advanced safety vehicle system. The proposed algorithm uses Block-DCT in extracting features from a given ROI(Region Of Interest) instead of using entire pixel values as in previous works. The proposed algorithm chooses parts of the DCT coefficients according to the proposed discriminant factor, uses correlation coefficients and variances among ROIs from training samples to reduce amount of arithmetic operations without performance degradation in classification process. The algorithm recognizes the speed limit signs using the information obtained during training process by calculating LDA and Mahalanobis Distance. To increase the hit rate of recognition, it uses accumulated classification results computed for a sequence of frames. Experimental results show that the hit rate of recognition for sequential frames reaches up to 100 %. When compared with previous works, numbers of multiply and add operations are reduced by 69.3 % and 67.9 %, respectively. Start after striking space key 2 times.

The Font Recognition of Printed Hangul Documents (인쇄된 한글 문서의 폰트 인식)

  • Park, Moon-Ho;Shon, Young-Woo;Kim, Seok-Tae;Namkung, Jae-Chan
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.8
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    • pp.2017-2024
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    • 1997
  • The main focus of this paper is the recognition of printed Hangul documents in terms of typeface, character size and character slope for IICS(Intelligent Image Communication System). The fixed-size blocks extracted from documents are analyzed in frequency domain for the typeface classification. The vertical pixel counts and projection profile of bounding box are used for the character size classification and the character slope classification, respectively. The MLP with variable hidden nodes and error back-propagation algorithm is used as typeface classifier, and Mahalanobis distance is used to classify the character size and slope. The experimental results demonstrated the usefulness of proposed system with the mean rate of 95.19% in typeface classification. 97.34% in character size classification, and 89.09% in character slope classification.

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