• Title/Summary/Keyword: Dimensionality Reduction

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SAR Recognition of Target Variants Using Channel Attention Network without Dimensionality Reduction (차원축소 없는 채널집중 네트워크를 이용한 SAR 변형표적 식별)

  • Park, Ji-Hoon;Choi, Yeo-Reum;Chae, Dae-Young;Lim, Ho
    • Journal of the Korea Institute of Military Science and Technology
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    • v.25 no.3
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    • pp.219-230
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    • 2022
  • In implementing a robust automatic target recognition(ATR) system with synthetic aperture radar(SAR) imagery, one of the most important issues is accurate classification of target variants, which are the same targets with different serial numbers, configurations and versions, etc. In this paper, a deep learning network with channel attention modules is proposed to cope with the recognition problem for target variants based on the previous research findings that the channel attention mechanism selectively emphasizes the useful features for target recognition. Different from other existing attention methods, this paper employs the channel attention modules without dimensionality reduction along the channel direction from which direct correspondence between feature map channels can be preserved and the features valuable for recognizing SAR target variants can be effectively derived. Experiments with the public benchmark dataset demonstrate that the proposed scheme is superior to the network with other existing channel attention modules.

The Kernel Trick for Content-Based Media Retrieval in Online Social Networks

  • Cha, Guang-Ho
    • Journal of Information Processing Systems
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    • v.17 no.5
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    • pp.1020-1033
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    • 2021
  • Nowadays, online or mobile social network services (SNS) are very popular and widely spread in our society and daily lives to instantly share, disseminate, and search information. In particular, SNS such as YouTube, Flickr, Facebook, and Amazon allow users to upload billions of images or videos and also provide a number of multimedia information to users. Information retrieval in multimedia-rich SNS is very useful but challenging task. Content-based media retrieval (CBMR) is the process of obtaining the relevant image or video objects for a given query from a collection of information sources. However, CBMR suffers from the dimensionality curse due to inherent high dimensionality features of media data. This paper investigates the effectiveness of the kernel trick in CBMR, specifically, the kernel principal component analysis (KPCA) for dimensionality reduction. KPCA is a nonlinear extension of linear principal component analysis (LPCA) to discovering nonlinear embeddings using the kernel trick. The fundamental idea of KPCA is mapping the input data into a highdimensional feature space through a nonlinear kernel function and then computing the principal components on that mapped space. This paper investigates the potential of KPCA in CBMR for feature extraction or dimensionality reduction. Using the Gaussian kernel in our experiments, we compute the principal components of an image dataset in the transformed space and then we use them as new feature dimensions for the image dataset. Moreover, KPCA can be applied to other many domains including CBMR, where LPCA has been used to extract features and where the nonlinear extension would be effective. Our results from extensive experiments demonstrate that the potential of KPCA is very encouraging compared with LPCA in CBMR.

Asymptotic Test for Dimensionality in Sliced Inverse Regression (분할 역회귀모형에서 차원결정을 위한 점근검정법)

  • Park, Chang-Sun;Kwak, Jae-Guen
    • The Korean Journal of Applied Statistics
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    • v.18 no.2
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    • pp.381-393
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    • 2005
  • As a promising technique for dimension reduction in regression analysis, Sliced Inverse Regression (SIR) and an associated chi-square test for dimensionality were introduced by Li (1991). However, Li's test needs assumption of Normality for predictors and found to be heavily dependent on the number of slices. We will provide a unified asymptotic test for determining the dimensionality of the SIR model which is based on the probabilistic principal component analysis and free of normality assumption on predictors. Illustrative results with simulated and real examples will also be provided.

Asymptotic Test for Dimensionality in Probabilistic Principal Component Analysis with Missing Values

  • Park, Chong-sun
    • Communications for Statistical Applications and Methods
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    • v.11 no.1
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    • pp.49-58
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    • 2004
  • In this talk we proposed an asymptotic test for dimensionality in the latent variable model for probabilistic principal component analysis with missing values at random. Proposed algorithm is a sequential likelihood ratio test for an appropriate Normal latent variable model for the principal component analysis. Modified EM-algorithm is used to find MLE for the model parameters. Results from simulations and real data sets give us promising evidences that the proposed method is useful in finding necessary number of components in the principal component analysis with missing values at random.

Multifactor Dimensionality Reduction(MDR) Analysis by Dummy Variables (더미(dummy) 변수를 활용한 다중인자 차원 축소(MDR) 방법)

  • Lee, Jea-Young;Lee, Ho-Guen
    • The Korean Journal of Applied Statistics
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    • v.22 no.2
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    • pp.435-442
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    • 2009
  • Multiple genes interacting is a difficult due to the limitations of parametric statistical method like as logistic regression for detection of gene effects that are dependent solely on interactions with other genes and with environmental exposures. Multifactor dimensionality reduction(MDR) statistical method by dummy variables was applied to identify interaction effects of single nucleotide polymorphisms(SNPs) responsible for longissimus mulcle dorsi area(LMA), carcass cold weight(CWT) and average daily gain(ADG) in a Hanwoo beef cattle population.

Structure Preserving Dimensionality Reduction : A Fuzzy Logic Approach

  • Nikhil R. Pal;Gautam K. Nandal;Kumar, Eluri-Vijaya
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.06a
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    • pp.426-431
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    • 1998
  • We propose a fuzzy rule based method for structure preserving dimensionality reduction. This method selects a small representative sample and applies Sammon's method to project it. The input data points are then augmented by the corresponding projected(output) data points. The augmented data set thus obtained is clustered with the fuzzy c-means(FCM) clustering algorithm. Each cluster is then translated into a fuzzy rule for projection. Our rule based system is computationally very efficient compared to Sammon's method and is quite effective to project new points, i.e., it has good predictability.

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Statistical Interaction for Major Gene Combinations (우수 유전자 조합 선별을 위한 통계적 상호작용 방법비교)

  • Lee, Jea-Young;Lee, Yong-Won;Choi, Young-Jin
    • The Korean Journal of Applied Statistics
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    • v.23 no.4
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    • pp.693-703
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    • 2010
  • Diseases of human or economical traits of cattles are occured by interaction of genes. We introduce expanded multifactor dimensionality reduction(E-MDR), dummy multifactor dimensionality reduction(D-MDR) and SNPHarvester which are developed to find interaction of genes. We will select interaction of outstanding gene combinations and select final best genotype groups.

A Real-Time Pattern Recognition for Multifunction Myoelectric Hand Control

  • Chu, Jun-Uk;Moon, In-Hyuk;Mun, Mu-Seong
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.842-847
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    • 2005
  • This paper proposes a novel real-time EMG pattern recognition for the control of a multifunction myoelectric hand from four channel EMG signals. To cope with the nonstationary signal property of the EMG, features are extracted by wavelet packet transform. For dimensionality reduction and nonlinear mapping of the features, we also propose a linear-nonlinear feature projection composed of PCA and SOFM. The dimensionality reduction by PCA simplifies the structure of the classifier, and reduces processing time for the pattern recognition. The nonlinear mapping by SOFM transforms the PCA-reduced features to a new feature space with high class separability. Finally a multilayer neural network is employed as the pattern classifier. We implement a real-time control system for a multifunction virtual hand. From experimental results, we show that all processes, including virtual hand control, are completed within 125 msec, and the proposed method is applicable to real-time myoelectric hand control without an operation time delay.

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Dimensionality Reduction Using PCA for Edge Computing (Edge Computing 환경에서의 PCA를 이용한 Dimensionality 감축 기법)

  • Lim, Hwan-Hee;Kim, Se-Jun;Kim, Kyoung-Tae;Youn, Hee-Yong
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2018.01a
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    • pp.95-96
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    • 2018
  • Edge Computing은 Cloud Computing의 단점을 보완하기 위해 등장 하였으나, 자원 제한을 가지고 있는 Edge Node에서 데이터 분석 및 처리해야 하는 문제점이 있다. 이를 해결하기 위해 K-means clustering 알고리즘과 PCA 기법을 이용해 차원 추축을 이용한 계산비용과 처리시간을 줄이는 기법을 제안하였다. PCA란, 차원 축소 및 데이터 압축에 사용되는 기계학습 알고리즘 중 하나이며, 데이터에서 중요한 정보만 추출해 차원을 줄일 수 있다. 이를 통해 제안한 기법이 기존의 Reduction first clustering second(RFCS) 기법에 비해 성능이 우수한 것을 확인할 수 있었다.

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A Method for Microarray Data Analysis based on Bayesian Networks using an Efficient Structural learning Algorithm and Data Dimensionality Reduction (효율적 구조 학습 알고리즘과 데이타 차원축소를 통한 베이지안망 기반의 마이크로어레이 데이타 분석법)

  • 황규백;장정호;장병탁
    • Journal of KIISE:Software and Applications
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    • v.29 no.11
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    • pp.775-784
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    • 2002
  • Microarray data, obtained from DNA chip technologies, is the measurement of the expression level of thousands of genes in cells or tissues. It is used for gene function prediction or cancer diagnosis based on gene expression patterns. Among diverse methods for data analysis, the Bayesian network represents the relationships among data attributes in the form of a graph structure. This property enables us to discover various relations among genes and the characteristics of the tissue (e.g., the cancer type) through microarray data analysis. However, most of the present microarray data sets are so sparse that it is difficult to apply general analysis methods, including Bayesian networks, directly. In this paper, we harness an efficient structural learning algorithm and data dimensionality reduction in order to analyze microarray data using Bayesian networks. The proposed method was applied to the analysis of real microarray data, i.e., the NC160 data set. And its usefulness was evaluated based on the accuracy of the teamed Bayesian networks on representing the known biological facts.