• Title/Summary/Keyword: l1-norm

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The Usage of Color & Edge Histogram Descriptors for Image Mining (칼라와 에지 히스토그램 기술자를 이용한 영상 마이닝 향상 기법)

  • An, Syungog;Park, Dong-Won;Singh, Kulwinder;Ma, Ming
    • The Journal of Korean Association of Computer Education
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    • v.7 no.5
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    • pp.111-120
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    • 2004
  • The MPEG-7 standard defines a set of descriptors that extracts low-level features such as color, texture and object shape from an image and generates metadata in order to represent these extracted information. But the matching performance for image mining ma y not be satisfactory by u sing only on e of these features. Rather than by combining these features we can achieve a better query performance. In this paper we propose a new image retrieval technique for image mining that combines the features extracted from MPEG-7 visual color and texture descriptors. Specifically, we use only some specifications of Scalable Color Descriptor (SCD) and Non-Homogeneous Texture Descriptor also known as Edge Histogram Descriptor (EHD) for the implementation of the color and edge histograms respectively. MPEG-7 standard defines $l_{1}$-norm based matching in EHD and SCD. But in our approach, for distance measurement, we achieve a better result by using cosine similarity coefficient for color histograms and Euclidean distance for edge histograms. Our approach toward this system is more experimental based than hypothetical.

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A Pansharpening Algorithm of KOMPSAT-3A Satellite Imagery by Using Dilated Residual Convolutional Neural Network (팽창된 잔차 합성곱신경망을 이용한 KOMPSAT-3A 위성영상의 융합 기법)

  • Choi, Hoseong;Seo, Doochun;Choi, Jaewan
    • Korean Journal of Remote Sensing
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    • v.36 no.5_2
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    • pp.961-973
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    • 2020
  • In this manuscript, a new pansharpening model based on Convolutional Neural Network (CNN) was developed. Dilated convolution, which is one of the representative convolution technologies in CNN, was applied to the model by making it deep and complex to improve the performance of the deep learning architecture. Based on the dilated convolution, the residual network is used to enhance the efficiency of training process. In addition, we consider the spatial correlation coefficient in the loss function with traditional L1 norm. We experimented with Dilated Residual Networks (DRNet), which is applied to the structure using only a panchromatic (PAN) image and using both a PAN and multispectral (MS) image. In the experiments using KOMPSAT-3A, DRNet using both a PAN and MS image tended to overfit the spectral characteristics, and DRNet using only a PAN image showed a spatial resolution improvement over existing CNN-based models.

Comparative analysis of methods for digital simulation (디지털 전산모사를 위한 방법론 비교분석)

  • Yi, Dokkyun;Park, Jieun
    • Journal of Digital Convergence
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    • v.13 no.9
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    • pp.209-218
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    • 2015
  • Computer simulation plays an important role for a theoretical foundation in convergence technology and the interpolation is to know the unknown values from known values on grid points. Therefore it is an important problem to select an interpolation method for digital simulation. The aim of this paper is to compare analysis of interpolation methods for digital simulation. we test six different interpolation methods namely: Quartic-Lagrangian, Cubic Spline, Fourier, Hermit, PWENO and SL-WENO. Through digital simulation of a linear advection equation, we analyse pros and cons for each method. In order to compare performance, we introduce accuracy computing and Error functions. The accuracy computing is used well-known $L^1-norm$ and the Error functions are dispersion function, dissipation function and total error function. High-order methods well apply to computer simulation, unfortunately, side-effects (Oscillation) happen.

Random Partial Haar Wavelet Transformation for Single Instruction Multiple Threads (단일 명령 다중 스레드 병렬 플랫폼을 위한 무작위 부분적 Haar 웨이블릿 변환)

  • Park, Taejung
    • Journal of Digital Contents Society
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    • v.16 no.5
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    • pp.805-813
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    • 2015
  • Many researchers expect the compressive sensing and sparse recovery problem can overcome the limitation of conventional digital techniques. However, these new approaches require to solve the l1 norm optimization problems when it comes to signal reconstruction. In the signal reconstruction process, the transform computation by multiplication of a random matrix and a vector consumes considerable computing power. To address this issue, parallel processing is applied to the optimization problems. In particular, due to huge size of original signal, it is hard to store the random matrix directly in memory, which makes one need to design a procedural approach in handling the random matrix. This paper presents a new parallel algorithm to calculate random partial Haar wavelet transform based on Single Instruction Multiple Threads (SIMT) platform.

A Study on Correlation between Power of Trunk Flexors, Extensors and Lumbar Lordotic Angle in Normal Adults (정상 성인에서 체간 굴근, 신근의 근력과 요추 전만각의 상관관계에 관한 연구)

  • Choi, Bo-Mi;Yi, Jeong-Min;Kim, Hyun-Soo
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.7 no.2
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    • pp.39-52
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    • 2012
  • Objectives : The purpose of this study was to investigate the correlation between lumbar lordotic angle and the power of trunk flexors, extensors in normal adults Methods : 34 normal participants participated in this study. Their lumbar lordotic angle(L1-S1 Cobb's angle and L1-L5 cobb's angle) was measured by x-ray taken on lateral direction, erect cross-arm position. And muscle power of trunk flexors and extensors of each participant measured using Cybex HUMAC NORM. Results : 1. The average of L1-S1 Cobb's angle was $47.21{\pm}8.88^{\circ}$ and the average of L1-L5 Cobb's angle was $36.32{\pm}9.62^{\circ}$(Table IV). 2. The average ratio of trunk flexors/extensors was $6.44{\pm}19.31%$(Table V). The average power of the trunk flexors was $165.18{\pm}55.05$(Newton-Meter/kg), and the power of trunk extensors was $257.18{\pm}85.53$ (Newton-Meter/kg)(Table VI). 3. Lumbar lordotic angle has no relation to the ratio of trunk flexors/extensors(Table VII, Fig. 4). 4. Lumbar lordotic angle has no relation to both the power of the trunk flexors and extensors(Table VIII, Fig. 5, Fig. 6). Conclusions : These results suggest that the lumbar lordotic angle measured by radiograph could not evaluate the power and ratio of trunk flexors, extensors.

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Robust Restoration of Barcode Signals (바코드 신호의 강인한 복원)

  • Lee, Han-A;Lee, Jeong-Tae
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.10
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    • pp.1859-1864
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    • 2007
  • Existing barcode signal restoration algorithms are not robust to unmodeled outliers that may exist in scanned barcode images due to scratches, dirts, etc. In this paper, we describe a robust barcode signal restoration algorithm that uses the hybrid $L_1-L_2$ norm as a similarity measure. To optimze the similarity measure, we propose a modified iterative reweighted least squares algorithm based on the one step minimization of a quadratic surrogate function. In the simulations and experiments with barcode images, the proposed method showed better robustness than the conventional MSE based method. In addition, the proposed method converged quickly during optimization process.

Approximation of Pulse Transfer Function of Impulse Response Data (임펄스응답 데이타의 펄스전달함수의 근사)

  • Lee, Dong-Cheol;Bae, Jong-Il;Chung, Hyeng-Hwan
    • Proceedings of the KIEE Conference
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    • 1999.07b
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    • pp.683-685
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    • 1999
  • As a method of obtaining pulse transfer function. transfer function of discrete-time from input-output data, there are method of obtaining unknown parameter of pulse transfer function from estimated impulse response before(1-3). There is no need to approximate to several meanings because of not being established algebraical relations between impulse response for estimation error and parameter of transfer function exactly. In this paper, I inquire the method[4] of obtaining the optimal pulse transfer function as a meaning of Hankel norm approximation from impulse response data and examine estimated property as computer simulation from this method.

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Face Recognition by Using Factorial Face Code of FP-ICA (FP-ICA의 인수부호에 의한 얼굴인식)

  • Cho, Yong-Hyun;Hong, Seong-Jun
    • Proceedings of the Korea Information Processing Society Conference
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    • 2005.05a
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    • pp.797-800
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    • 2005
  • 본 논문에서는 고정점 알고리즘의 독립성분분석을 이용하여 얼굴영상의 인수부호를 찾아 얼굴을 인식하는 기법을 제안하였다. 여기서 고정점 알고리즘은 뉴우턴법에 기초한 것으로 빠른 특징추출을 위함이고, 독립성분분석의 이용은 통계적으로 독립인 계수로 구성된 인수부호를 효과적으로 추출하기 위함이다. 제안된 기법을 Yale 얼굴영상 데이터베이스로부터 선택된 20개의 $324{\ast}243$ 픽셀의 영상을 대상으로 시뮬레이션한 결과, 기저영상의 개수에 따른 압축성능과 L1- 및 L2-norm의 거리척도에 따른 분류에서 우수한 인식성능이 있음을 확인할 수 있었다.

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Adaptive Hyperspectral Image Classification Method Based on Spectral Scale Optimization

  • Zhou, Bing;Bingxuan, Li;He, Xuan;Liu, Hexiong
    • Current Optics and Photonics
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    • v.5 no.3
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    • pp.270-277
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    • 2021
  • The adaptive sparse representation (ASR) can effectively combine the structure information of a sample dictionary and the sparsity of coding coefficients. This algorithm can effectively consider the correlation between training samples and convert between sparse representation-based classifier (SRC) and collaborative representation classification (CRC) under different training samples. Unlike SRC and CRC which use fixed norm constraints, ASR can adaptively adjust the constraints based on the correlation between different training samples, seeking a balance between l1 and l2 norm, greatly strengthening the robustness and adaptability of the classification algorithm. The correlation coefficients (CC) can better identify the pixels with strong correlation. Therefore, this article proposes a hyperspectral image classification method called correlation coefficients and adaptive sparse representation (CCASR), based on ASR and CC. This method is divided into three steps. In the first step, we determine the pixel to be measured and calculate the CC value between the pixel to be tested and various training samples. Then we represent the pixel using ASR and calculate the reconstruction error corresponding to each category. Finally, the target pixels are classified according to the reconstruction error and the CC value. In this article, a new hyperspectral image classification method is proposed by fusing CC and ASR. The method in this paper is verified through two sets of experimental data. In the hyperspectral image (Indian Pines), the overall accuracy of CCASR has reached 0.9596. In the hyperspectral images taken by HIS-300, the classification results show that the classification accuracy of the proposed method achieves 0.9354, which is better than other commonly used methods.

A RANDOM DISPERSION SCHRÖDINGER EQUATION WITH NONLINEAR TIME-DEPENDENT LOSS/GAIN

  • Jian, Hui;Liu, Bin
    • Bulletin of the Korean Mathematical Society
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    • v.54 no.4
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    • pp.1195-1219
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    • 2017
  • In this paper, the limit behavior of solution for the $Schr{\ddot{o}}dinger$ equation with random dispersion and time-dependent nonlinear loss/gain: $idu+{\frac{1}{{\varepsilon}}}m({\frac{t}{{\varepsilon}^2}}){\partial}_{xx}udt+{\mid}u{\mid}^{2{\sigma}}udt+i{\varepsilon}a(t){\mid}u{\mid}^{2{\sigma}_0}udt=0$ is studied. Combining stochastic Strichartz-type estimates with $L^2$ norm estimates, we first derive the global existence for $L^2$ and $H^1$ solution of the stochastic $Schr{\ddot{o}}dinger$ equation with white noise dispersion and time-dependent loss/gain: $idu+{\Delta}u{\circ}d{\beta}+{\mid}u{\mid}^{2{\sigma}}udt+ia(t){\mid}u{\mid}^{2{\sigma}_0}udt=0$. Secondly, we prove rigorously the global diffusion-approximation limit of the solution for the former as ${\varepsilon}{\rightarrow}0$ in one-dimensional $L^2$ subcritical and critical cases.