• 제목/요약/키워드: principle component analysis

검색결과 386건 처리시간 0.025초

주성분 분석과 서포트 백터 머신을 이용한 효과적인 얼굴 검출 시스템 (Effective Face Detection Using Principle Component Analysis and Support Vector Machine)

  • 강병두;권오화;성치영;전재덕;엄재성;김종호;이재원;김상균
    • 한국멀티미디어학회논문지
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    • 제9권11호
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    • pp.1435-1444
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    • 2006
  • 본 논문은 얼굴 영상에서 추출된 특징 값들을 주성분 분석(Principle Component Analysis; 이하 PCA)을 이용하여 재해석하고, 서포트 벡터 머신(Support Vector Machine; 이하 SVM)을 이용한 이진 분류를 통하여 효과적이면서 실시간으로 얼굴을 검출할 수 있는 방법론을 제안한다. 얼굴과 얼굴이 아닌 영상들로 학습데이터를 구성하여, 이 영상들로부터 Haar-like 특징값들을 추출한다. 추출된 다량의 특징 값들 중에 얼굴과 얼굴이 아닌 영역에 대하여 판별 능력이 우수한 특징값들은 PCA를 이용하여 재해석되고 유용한 특징들을 선별한다. 선별된 특징들을 SVM의 입력 차원으로 사용하여 최종 분류기를 학습 및 구성한다. 제안하는 분류기는 학습데이터 집단의 구성에 크게 영향을 받지 않고, 소량의 학습데이터만으로도 90.1%의 만족할만한 얼굴 검출률을 보여주며, $320{\times}240$ 크기의 영상에 대하여 실시간 얼굴 검출에 사용 가능한 초당 8프레임의 처리속도를 보여주었다.

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Theoretical and experimental study on damage detection for beam string structure

  • He, Haoxiang;Yan, Weiming;Zhang, Ailin
    • Smart Structures and Systems
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    • 제12권3_4호
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    • pp.327-344
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    • 2013
  • Beam string structure (BSS) is introduced as a new type of hybrid prestressed string structures. The composition and mechanics features of BSS are discussed. The main principles of wavelet packet transform (WPT), principal component analysis (PCA) and support vector machine (SVM) have been reviewed. WPT is applied to the structural response signals, and feature vectors are obtained by feature extraction and PCA. The feature vectors are used for training and classification as the inputs of the support vector machine. The method is used to a single one-way arched beam string structure for damage detection. The cable prestress loss and web members damage experiment for a beam string structure is carried through. Different prestressing forces are applied on the cable to simulate cable prestress loss, the prestressing forces are calculated by the frequencies which are solved by Fourier transform or wavelet transform under impulse excitation. Test results verify this method is accurate and convenient. The damage cases of web members on the beam are tested to validate the efficiency of the method presented in this study. Wavelet packet decomposition is applied to the structural response signals under ambient vibration, feature vectors are obtained by feature extraction method. The feature vectors are used for training and classification as the inputs of the support vector machine. The structural damage position and degree can be identified and classified, and the test result is highly accurate especially combined with principle component analysis.

Construction of Scientific Impact Evaluation Model Based on Altmetrics

  • Li, Jiapei;Shin, Seong Yoon;Lee, Hyun Chang
    • Journal of information and communication convergence engineering
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    • 제15권3호
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    • pp.165-169
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    • 2017
  • Altmetrics is an emergent research area whereby social media is applied as a source of metrics to evaluate scientific impact. Recently, the interest in altmetrics has been growing. Traditional scientific impact evaluation indictors are based on the number of publications, citation counts and peer reviews of a researcher. As research publications were increasingly placed online, usage metrics as well as webometrics appeared. This paper explores the potential benefits of altmetrics and the deep relationship between each metrics. Firstly, we found a weak-to-medium correlation among the 11 altmetrics and visualized such correlation. Secondly, we conducted principal component analysis and exploratory factor analysis on altmetrics of social media, divided the 11 altmetrics into four feature sets, confirming the dispersion and relative concentration of altmetrics groups and developed the altmetrics evaluation model. We can use this model to evaluate the scientific impact of articles on social media.

차체 구조물의 피로수명 예측을 위한 컴퓨터 시뮬레이션 방법에 관한 연구 (A Study on Computational Method for Fatigue Life Prediction of Vehicle Structures)

  • 이상범;박태원;임홍재
    • 소음진동
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    • 제10권4호
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    • pp.686-691
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    • 2000
  • In this paper a computer aided analysis method is proposed for durability assessment in the early design stages using dynamic analysis, stress analysis and fatigue life prediction method. From dynamic analysis of a vehicle suspension system, dynamic load time histories of a suspension component are calculated. From the dynamic load time histories and the stress of the suspension component, a dynamic stress time history at the critical location is produced using the superposition principle. Using linear damage law and cycle counting method, fatigue life cycle is calculated. The predicted fatigue life cycle is verified by experimental durability tests.

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차체 구조물의 피로수명 예측을 위한 컴퓨터 시뮬레이션 방법에 관한 연구 (A Study on Computational Method for Fatigue Life Prediction of Vehicle Structures)

  • 이상범;박태원;박종성;이선병;임홍재
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 춘계학술대회논문집
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    • pp.1883-1888
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    • 2000
  • In this paper a computer aided analysis method is proposed for durability assessment in the early design stages using dynamic analysis, stress analysis and fatigue life prediction method. From dynamic analysis of a vehicle suspension system, dynamic load time histories of a suspension component are calculated. From the dynamic load time histories and the stress of the suspension component, a dynamic stress time history at the critical location is produced using the superposition principle. Using linear damage law and cycle counting method, fatigue life cycle is calculated. The predicted fatigue life cycle is verified by experimental durability tests.

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모드합성법을 이용한 음향부분구조합성법의 개발 (Development of Acoustic Substructure Synthesis Method using Component Mode Synthesis Method)

  • 고상철;조용구;오재응;김준태;김진오
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1996년도 추계학술대회논문집; 한국과학기술회관, 8 Nov. 1996
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    • pp.118-123
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    • 1996
  • The purpose of this study is to develop acoustic substructure synthesis method that can be applied to acoustic modal analysis of complex acoustic systems. Acoustic modal analysis method to be introduced here is a method that analyze acoustic natural mode shape of the complex acoustic system by the principle of CMS(component mode synthesis method). This paper describes the acoustic modal analysis of the acoustic finite element model of simple expansion pipe by acoustic substructure synthesis method. The results of acoustic modal analysis analyzed by Acoustic substructure synthesis method and the results, by FEM(finite element method) shows good agreement.

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Seismic response of a high-rise flexible structure under H-V-R ground motion

  • We, Wenhui;Hu, Ying;Jiang, Zhihan
    • Earthquakes and Structures
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    • 제23권2호
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    • pp.169-181
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    • 2022
  • To research the dynamic response of the high-rise structure under the rocking ground motion, which we believed that the effect cannot be ignored, especially accompanied by vertical ground motion. Theoretical analysis and shaking table seismic simulation tests were used to study the response of a high-rise structure to excitation of a H-V-R ground motion that included horizontal, vertical, and rocking components. The use of a wavelet analysis filtering technique to extract the rocking component from data for the primary horizontal component in the first part, based on the principle of horizontal pendulum seismogram and the use of a wavelet analysis filtering technique. The dynamic equation of motion for a high-rise structure under H-V-R ground motion was developed in the second part, with extra P-△ effect due to ground rocking displacement was included in the external load excitation terms of the equation of motion, and the influence of the vertical component on the high-rise structure P-△ effect was also included. Shaking table tests were performed for H-V-R ground motion using a scale model of a high-rise TV tower structure in the third part, while the results of the shaking table tests and theoretical calculation were compared in the last part, and the following conclusions were made. The results of the shaking table test were consistent with the theoretical calculation results, which verified the accuracy of the theoretical analysis. The rocking component of ground motion significantly increased the displacement of the structure and caused an asymmetric displacement of the structure. Thus, the seismic design of an engineering structure should consider the additional P-△ effect due to the rocking component. Moreover, introducing the vertical component caused the geometric stiffness of the structure to change with time, and the influence of the rocking component on the structure was amplified due to this effect.

농촌체험프로그램 운영 유형 및 실태분석 : 농촌마을종합개발사업을 중심으로 (Operational Management System and Characteristics Analysis on the Rural Experience Programs: the Case of Comprehensive Rural Village Development Projects)

  • 황한철;노용식;박정수
    • 농촌계획
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    • 제21권2호
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    • pp.103-114
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    • 2015
  • The comprehensive rural village development projects (CRVDP) have been carried out as the core one of the rural development schemes in Korea since 2004. CRVDP included the various rural experience programs to increase rural income and in order to promote rural community development in the project area. This study analyzed the operating management conditions, types and characteristics of the rural experience programs targeting the 168 CRVDPs have been completed so that the recommendations and lessons which were found the usefulness, challenges and improvements to the CRVDP can be provided to be better the same kinds of rural development projects. We identified the relationships between performances such as increasing village income and utilization of rural amenity resources to the CRVDP and operational management types of the rural experience programs as well. Employing principle component analysis and cluster analysis technique, this study found 5 clusters of rural experience programs among 168 CRVDPs. The results of analysis of variance indicated that there were significant the mean differences between clusters such as the utilization of rural amenity resources(0.01), income of rural experience programs(0.1). According to the result of the Chi-squire test, there was very significant differences between internet homepage operation and clusters(0.01). Finally, the analysis of covariance about the income of rural experience programs showed that there were significant the mean differences between clusters(0.05).

Probabilistic penalized principal component analysis

  • Park, Chongsun;Wang, Morgan C.;Mo, Eun Bi
    • Communications for Statistical Applications and Methods
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    • 제24권2호
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    • pp.143-154
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    • 2017
  • A variable selection method based on probabilistic principal component analysis (PCA) using penalized likelihood method is proposed. The proposed method is a two-step variable reduction method. The first step is based on the probabilistic principal component idea to identify principle components. The penalty function is used to identify important variables in each component. We then build a model on the original data space instead of building on the rotated data space through latent variables (principal components) because the proposed method achieves the goal of dimension reduction through identifying important observed variables. Consequently, the proposed method is of more practical use. The proposed estimators perform as the oracle procedure and are root-n consistent with a proper choice of regularization parameters. The proposed method can be successfully applied to high-dimensional PCA problems with a relatively large portion of irrelevant variables included in the data set. It is straightforward to extend our likelihood method in handling problems with missing observations using EM algorithms. Further, it could be effectively applied in cases where some data vectors exhibit one or more missing values at random.

텍스처 정보 기반의 PCA를 이용한 문서 영상의 분석 (Texture-based PCA for Analyzing Document Image)

  • 김보람;김욱현
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2006년도 하계종합학술대회
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    • pp.283-284
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    • 2006
  • In this paper, we propose a novel segmentation and classification method using texture features for the document image. First, we extract the local entropy and then segment the document image to separate the background and the foreground using the Otsu's method. Finally, we classify the segmented regions into each component using PCA(principle component analysis) algorithm based on the texture features that are extracted from the co-occurrence matrix for the entropy image. The entropy-based segmentation is robust to not only noise and the change of light, but also skew and rotation. Texture features are not restricted from any form of the document image and have a superior discrimination for each component. In addition, PCA algorithm used for the classifier can classify the components more robustly than neural network.

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