• Title/Summary/Keyword: structure sparsity

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An Analysis on the Visual Structure from the Building Area around An-ap Pond (안압지 호안 건물지의 조망 경관구조 분석)

  • 박경자;이관규;양병이
    • Journal of the Korean Institute of Landscape Architecture
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    • v.29 no.2
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    • pp.14-21
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    • 2001
  • This study aims to analyze visual structure by evaluating the view from five building sites around An-ap pond, and attempt to determine which site commands the best view and will provide the most active use. The results of this study can be summarized as follows: According to the questionnaire survey of experts on the relations of dominancy-subordination(´chu-jong´), vacancy-solidness(´heo-sil´), sparsity-density(´so-mil´) based on ancient oriental Yin-Yang theory and analysis of visual structure on angle of elevation, depression, and the landscape-component ratio to be seen through five building sites around the west of An-ap pond, building site three was selected as the building site which has the best landscape. Therefore, it is estimated that building site three played the role of core-building site. According to the result of correlation analysis, the greater the increased in the component ratio of sky, mountain ,the greater the degree of harmony within the landscape. As well, the degree of harmony increased when the landscape component ratio of a distant view was greater than that of a near view. Moreover, it was proved that the relationships of ´chu-jong´, ´heo-sil´, ´so-mil´ are correlative, not independent.

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Analysis of Symmetric and Periodic Open Boundary Problem by Coupling of FEM and Fourier Series

  • Kim, Young Sun
    • Journal of Magnetics
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    • v.18 no.2
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    • pp.130-134
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    • 2013
  • Most electrical machines like motor, generator and transformer are symmetric in terms of magnetic field distribution and mechanical structure. In order to analyze these problems effectively, many coupling techniques have been introduced. This paper deals with a coupling scheme for open boundary problem of symmetric and periodic structure. It couples an analytical solution of Fourier series expansion with the standard finite element method. The analytical solution is derived for the magnetic field in the outside of the boundary, and the finite element method is for the magnetic field in the inside with source current and magnetic materials. The main advantage of the proposed method is that it retains sparsity and symmetry of system matrix like the standard FEM and it can also be easily applied to symmetric and periodic problems. Also, unknowns of finite elements at the boundary are coupled with Fourier series coefficients. The boundary conditions are used to derive a coupled system equation expressed in matrix form. The proposed algorithm is validated using a test model of a bush bar for the power supply. And the each result is compared with analytical solution respectively.

Adaptive ridge procedure for L0-penalized weighted support vector machines

  • Kim, Kyoung Hee;Shin, Seung Jun
    • Journal of the Korean Data and Information Science Society
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    • v.28 no.6
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    • pp.1271-1278
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    • 2017
  • Although the $L_0$-penalty is the most natural choice to identify the sparsity structure of the model, it has not been widely used due to the computational bottleneck. Recently, the adaptive ridge procedure is developed to efficiently approximate a $L_q$-penalized problem to an iterative $L_2$-penalized one. In this article, we proposed to apply the adaptive ridge procedure to solve the $L_0$-penalized weighted support vector machine (WSVM) to facilitate the corresponding optimization. Our numerical investigation shows the advantageous performance of the $L_0$-penalized WSVM compared to the conventional WSVM with $L_2$ penalty for both simulated and real data sets.

Parallel Computation Algorithm of Gauss Elimination in Power system Analysis (전력계통의 자코비안행렬 가우스소거의 병렬계산)

  • Suh, Eui-Suk;Oh, Tae-Kyoo
    • Proceedings of the KIEE Conference
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    • 1993.07a
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    • pp.163-166
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    • 1993
  • This paper describes an parallell computing algorithm in Gauss elimination of Jacobian matrix to large-scale power system. The structure of Jacobian matrix becomes different according to ordering method of buses. In sequential computation buses are ordered to minimize the number of fill-in in the triangulation of the Jacobian matrix. The proposed method using ND(nested dissection) ordering develops the parallelism in the Gauss elimination to have balance of computing load among processes and each processor uses the sequential computation method to preserve the sparsity of matrix.

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Tucker Modeling based Kronecker Constrained Block Sparse Algorithm

  • Zhang, Tingping;Fan, Shangang;Li, Yunyi;Gui, Guan;Ji, Yimu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.2
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    • pp.657-667
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    • 2019
  • This paper studies synthetic aperture radar (SAR) imaging problem which the scatterers are often distributed in block sparse pattern. To exploiting the sparse geometrical feature, a Kronecker constrained SAR imaging algorithm is proposed by combining the block sparse characteristics with the multiway sparse reconstruction framework with Tucker modeling. We validate the proposed algorithm via real data and it shows that the our algorithm can achieve better accuracy and convergence than the reference methods even in the demanding environment. Meanwhile, the complexity is smaller than that of the existing methods. The simulation experiments confirmed the effectiveness of the algorithm as well.

A Tree Regularized Classifier-Exploiting Hierarchical Structure Information in Feature Vector for Human Action Recognition

  • Luo, Huiwu;Zhao, Fei;Chen, Shangfeng;Lu, Huanzhang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.3
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    • pp.1614-1632
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    • 2017
  • Bag of visual words is a popular model in human action recognition, but usually suffers from loss of spatial and temporal configuration information of local features, and large quantization error in its feature coding procedure. In this paper, to overcome the two deficiencies, we combine sparse coding with spatio-temporal pyramid for human action recognition, and regard this method as the baseline. More importantly, which is also the focus of this paper, we find that there is a hierarchical structure in feature vector constructed by the baseline method. To exploit the hierarchical structure information for better recognition accuracy, we propose a tree regularized classifier to convey the hierarchical structure information. The main contributions of this paper can be summarized as: first, we introduce a tree regularized classifier to encode the hierarchical structure information in feature vector for human action recognition. Second, we present an optimization algorithm to learn the parameters of the proposed classifier. Third, the performance of the proposed classifier is evaluated on YouTube, Hollywood2, and UCF50 datasets, the experimental results show that the proposed tree regularized classifier obtains better performance than SVM and other popular classifiers, and achieves promising results on the three datasets.

Group-Sparse Channel Estimation using Bayesian Matching Pursuit for OFDM Systems

  • Liu, Yi;Mei, Wenbo;Du, Huiqian
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.2
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    • pp.583-599
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    • 2015
  • We apply the Bayesian matching pursuit (BMP) algorithm to the estimation of time-frequency selective channels in orthogonal frequency division multiplexing (OFDM) systems. By exploiting prior statistics and sparse characteristics of propagation channels, the Bayesian method provides a more accurate and efficient detection of the channel status information (CSI) than do conventional sparse channel estimation methods that are based on compressive sensing (CS) technologies. Using a reasonable approximation of the system model and a skillfully designed pilot arrangement, the proposed estimation scheme is able to address the Doppler-induced inter-carrier interference (ICI) with a relatively low complexity. Moreover, to further reduce the computational cost of the channel estimation, we make some modifications to the BMP algorithm. The modified algorithm can make good use of the group-sparse structure of doubly selective channels and thus reconstruct the CSI more efficiently than does the original BMP algorithm, which treats the sparse signals in the conventional manner and ignores the specific structure of their sparsity patterns. Numerical results demonstrate that the proposed Bayesian estimation has a good performance over rapidly time-varying channels.

The Structure and the Convergence Characteristics Analysis on the Generalized Subband Decomposition FIR Adaptive Filter in Wavelet Transform Domain (웨이블릿 변환을 이용한 일반화된 서브밴드 분해 FIR 적응 필터의 구조와 수렴특성 해석)

  • Park, Sun-Kyu;Park, Nam-Chun
    • Journal of the Institute of Convergence Signal Processing
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    • v.9 no.4
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    • pp.295-303
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    • 2008
  • In general, transform domain adaptive filters show faster convergence speed than the time domain adaptive filters, but the amount of calculation increases dramatically as the filter order increases. This problem can be solved by making use of the subband structure in transform domain adaptive filters. In this paper, to increase the convergence speed on the generalized subband decomposition FIR adaptive filters, a structure of the adaptive filter with subfilter of dyadic sparsity factor in wavelet transform domain is designed. And, in this adaptive filter, the equivalent input in transform domain is derived and, by using the input, the convergence properties for the LMS algorithm is analyzed and evaluated. By using this sub band adaptive filter, the inverse system modeling and the periodic noise canceller were designed, and, by computer simulation, the convergence speeds of the systems on LMS algorithm were compared with that of the subband adaptive filter using DFT(discrete Fourier transform).

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A Analysis on the Relations among Characters shown in SBS Wednesday and Thursday Dramas -Focusing on the Greimas' Actantial Model- (SBS 수목드라마에서 나타난 등장인물 관계분석 -그레마스 행위소 모델 중심으로-)

  • Lim, Woon-Joo
    • Journal of Digital Convergence
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    • v.13 no.1
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    • pp.481-486
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    • 2015
  • This study aimed to analyze how a variety of relations created by the actions of characters shown in SBS Wednesday and Thursday dramas are communicated by using Greimas' actantial model. This study analyzed the sparsity structure that the subject have in relations between the subject, and a desire structure that the subject have will appear if we look into the interactive and binding relation between the subject and the object in the process of solving those problems. In the relations between the subject and originator, the role of originator in the dramas was limited when his or her character is established as a poor character weaker than the subject and the one to be protected, whereas he or she was more authoritative than the subject in the structure that originator shares a role as an antagonist. Objectors shown in three works gave help to the solution of incident after all by turning coat as another cooperators of the subject and the object, showing a tendency to reach maturity rather than being unhappy.

A Sparse Target Matrix Generation Based Unsupervised Feature Learning Algorithm for Image Classification

  • Zhao, Dan;Guo, Baolong;Yan, Yunyi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.6
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    • pp.2806-2825
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    • 2018
  • Unsupervised learning has shown good performance on image, video and audio classification tasks, and much progress has been made so far. It studies how systems can learn to represent particular input patterns in a way that reflects the statistical structure of the overall collection of input patterns. Many promising deep learning systems are commonly trained by the greedy layerwise unsupervised learning manner. The performance of these deep learning architectures benefits from the unsupervised learning ability to disentangling the abstractions and picking out the useful features. However, the existing unsupervised learning algorithms are often difficult to train partly because of the requirement of extensive hyperparameters. The tuning of these hyperparameters is a laborious task that requires expert knowledge, rules of thumb or extensive search. In this paper, we propose a simple and effective unsupervised feature learning algorithm for image classification, which exploits an explicit optimizing way for population and lifetime sparsity. Firstly, a sparse target matrix is built by the competitive rules. Then, the sparse features are optimized by means of minimizing the Euclidean norm ($L_2$) error between the sparse target and the competitive layer outputs. Finally, a classifier is trained using the obtained sparse features. Experimental results show that the proposed method achieves good performance for image classification, and provides discriminative features that generalize well.