This paper proposes a neural network that stores and retrieves sparse patterns categorically, the patterns being random realizations of a sequence of biased (0, 1) Bernoulli trials, The neural network, denoted as cate...
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This paper proposes a neural network that stores and retrieves sparse patterns categorically, the patterns being random realizations of a sequence of biased (0, 1) Bernoulli trials, The neural network, denoted as categorizing associative memory, consists of two modules: 1) an adaptive classifier (AC) module that categorizes input data and 2) an associative memory (AM) module that stores input patterns in each category according to a Hebbian learning rule, after the AC module has stabilized its learning of that category. We show that during Braining of the AC module, the weights in the AC module belonging to a category converge to the probability of a ''1'' occurring in a pattern from that category, This fact is used to set the thresholds of the AM module optimally without requiring any a priori knowledge about the stored patterns.
Keyframe selection is a common way to summarize video contents. However, delimiting shot boundaries to extract a representative keyframe from each shot is not trivial as most shot boundary techniques are heuristic and...
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Keyframe selection is a common way to summarize video contents. However, delimiting shot boundaries to extract a representative keyframe from each shot is not trivial as most shot boundary techniques are heuristic and sensitive to the types of video transitions. This paper proposes a new shot boundary detection algorithm, that learns a dictionary from the given video using sparse coding and updates atoms in the dictionary, following the philosophy that different shots cannot be reconstructed using the learned dictionary. Technically, our algorithm conducts the learning by simultaneously minimizing the reconstruction loss, restricting the sparsity of the reconstruction matrix, and preserving the structure across patches and frames. Once shot boundaries are determined, one representative keyframe is selected from each shot and then a video summary is constructed by concatenating the representative keyframes through a post process. On two standard video datasets across various genres, i.e., VSUMM and YouTube datasets, our method is shown to be powerful for video summarization with superior performance over several state-of-the-art techniques. (C) 2017 Elsevier B.V. All rights reserved.
sparse coding has received an increasing amount of interest in recent years. It finds a basis set that captures high-level semantics in the data and learns sparse coordinates in terms of the basis set. However, most o...
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sparse coding has received an increasing amount of interest in recent years. It finds a basis set that captures high-level semantics in the data and learns sparse coordinates in terms of the basis set. However, most of the existing approaches fail to consider the geometrical structure of the data space. Recently, a graph regularized sparse coding (GraphSC) is proposed to learn the sparse representations that explicitly take into account the local manifold structure, which used graph Laplacian as a smooth operator. However, the GraphSC based on graph Laplacian suffers from the fact that sparse coordinates are biased toward a constant and the Laplacian embedding often cannot preserve local topology well as we expected. In this paper, we propose a novel sparse coding algorithm called Hessian sparse coding (HessianSC). HessianSC is based on the second-order Hessian energy, which favors functions whose values vary linearly with respect to geodesic distance. HessianSC can overcome the drawbacks of Laplacian based methods. We show that our algorithm results in significantly improved performance when applied to image clustering task. (C) 2013 Elsevier B.V. All rights reserved.
The traditional image quality assessments, such as the mean squared error (MSE), the signal-to-noise ratio (SNR), and the Peak signal-to-noise ratio (PSNR), are all based on the absolute error of images. Structural si...
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The traditional image quality assessments, such as the mean squared error (MSE), the signal-to-noise ratio (SNR), and the Peak signal-to-noise ratio (PSNR), are all based on the absolute error of images. Structural similarity (SSIM) index is another important image quality assessment which has been shown to be more effective in the human vision system (HVS). Although there are many essential differences between MSE and SSIM, some important associations exist between them. In this paper, the associations between MSE and SSIM as cost functions in linear decomposition are investigated. Based on the associ-ations, a bit-allocation algorithm for sparse coding is proposed by considering both the reconstructed image quality and the reconstructed image contrast. In the proposed algorithm, the space occupied by a linear coefficient of a basis in sparse coding is reduced to only 9 to 10 bits, in which 1 bit is used to save the sign of linear coefficient, 3 bits are used to save the number of powers of 10 in scientific notation, and only 5 to 6 bits are used to save the significance digits. The experimental results show that the proposed bit-allocation algorithm for sparse coding can maintain both the image quality and the image contrast well. (c) 2020 Elsevier B.V. All rights reserved.
sparse coding represents a signal sparsely by using an overcomplete dictionary, and obtains promising performance in practical computer vision applications, especially for signal restoration tasks such as image denois...
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sparse coding represents a signal sparsely by using an overcomplete dictionary, and obtains promising performance in practical computer vision applications, especially for signal restoration tasks such as image denoising and image inpainting. In recent years, many discriminative sparse coding algorithms have been developed for classification problems, but they cannot naturally handle visual data represented by multiview features. In addition, existing sparse coding algorithms use graph Laplacian to model the local geometry of the data distribution. It has been identified that Laplacian regularization biases the solution towards a constant function which possibly leads to poor extrapolating power. In this paper, we present multiview Hessian discriminative sparse coding (mHDSC) which seamlessly integrates Hessian regularization with discriminative sparse coding for multiview learning problems. In particular, mHDSC exploits Hessian regularization to steer the solution which varies smoothly along geodesics in the manifold, and treats the label information as an additional view of feature for incorporating the discriminative power for image annotation. We conduct extensive experiments on PASCAL VOC'07 dataset and demonstrate the effectiveness of mHDSC for image annotation. (C) 2013 Elsevier Inc. All rights reserved.
This paper presents a single-trial evoked potential (EP) estimation method based on an autoregressive model with exogenous input modeling and sparse coding. This method uses sparse coding instead of the autoregressive...
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This paper presents a single-trial evoked potential (EP) estimation method based on an autoregressive model with exogenous input modeling and sparse coding. This method uses sparse coding instead of the autoregressive-moving-average model to model EPs, as the former is more flexible. The best matching atoms from the dictionary are used to represent the EP signal without needing to estimate the number of atoms beforehand. By transforming the electroencephalography signal into white noise, the single-trial EP estimation is transformed into a signal denoising problem for white noise. With the dictionary constructed specially for EPs, the EP signal can be extracted easily with sparse coding. Moreover, since the location of the atom in the dictionary has no influence on the effectiveness of sparse decomposition, variations of the amplitude and latency of EPs have only a minor impact on the performance of the proposed method. The proposed method can thus track EP signal variations. Experimental results also demonstrate that this method is effective.
The theoretical, practical and technical development of neural associative memories during the last 40 years is described. The importance of sparse coding of associative memory patterns is pointed out. The use of asso...
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The theoretical, practical and technical development of neural associative memories during the last 40 years is described. The importance of sparse coding of associative memory patterns is pointed out. The use of associative memory networks for large scale brain modeling is also mentioned. (C) 2012 Elsevier Ltd. All rights reserved.
As an emerging technology, device-free localization (DFL) using wireless sensor networks to detect targets not carrying any electronic devices, has spawned extensive applications, such as security safeguards and smart...
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As an emerging technology, device-free localization (DFL) using wireless sensor networks to detect targets not carrying any electronic devices, has spawned extensive applications, such as security safeguards and smart homes or hospitals. Previous studies formulate DFL as a classification problem, but there are still some challenges in terms of accuracy and robustness. In this paper, we exploit a generalized thresholding algorithm with parameter p as a penalty function to solve inverse problems with sparsity constraints for DFL. The function applies less bias to the large coefficients and penalizes small coefficients by reducing the value of p. By taking the distinctive capability of the p thresholding function to measure sparsity, the proposed approach can achieve accurate and robust localization performance in challenging environments. Extensive experiments show that the algorithm outperforms current alternatives.
sparse coding provides a powerful means to perform feature extraction on high-dimensional data and recently has attracted broad interest for applications. However, it still suffers from a big challenge to realize real...
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sparse coding provides a powerful means to perform feature extraction on high-dimensional data and recently has attracted broad interest for applications. However, it still suffers from a big challenge to realize real-time energy-efficient feature extraction with conventional CPUs/GPUs owing to its highly intensive computation. Benefitting from the non-volatility, low power, high speed, great scalability, and good compatibility with CMOS technology, spintronic devices, such as magnetic tunnel junction and domain wall motion (DWM) device, have been explored for applications, ranging from memory, logic, to neuromorphic computing. In this paper, we explore the possibility of hardware acceleration implementation of the sparse coding algorithm with spintronic devices by a series of design optimizations across the algorithm, architecture, circuit, and device. First, one sparse coding algorithm is selected well suited for parallelization and hardware acceleration. Then, a DWM-based compound spintronic device (CSD) is engineered and modeled, which is envisioned to achieve multiple conductance states. Sequentially, a parallel architecture is presented based on a dense cross-point array of the proposed DWM-based CSD, which can be envisioned to accelerate the selected sparse coding algorithm with a designed dedicated periphery read and write circuit owing to its massively parallel read and write operation. Experimental results show that the selected sparse coding algorithm can be accelerated by 1400x with the proposed parallel architecture in comparison with software implementation. Moreover, its energy dissipation is eight orders of magnitude smaller than that with software implementation. Additionally, an artificial neural circuit (ANC) with the proposed DWM-based CSD is also presented, which can achieve a multi-step transfer function. By using the proposed DWM-based CSD as a single synapse and the proposed ANC as one neuron, a fully forward-connected artificial neural netwo
Galerkin projection is a commonly used reduced order modeling approach;however, stability and accuracy of the resulting models are open issues for unsteady flow fields. Balance between production and dissipation of en...
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Galerkin projection is a commonly used reduced order modeling approach;however, stability and accuracy of the resulting models are open issues for unsteady flow fields. Balance between production and dissipation of energy is crucial for stability. Moreover, the rates of energy production and dissipation are function of large- and small-scale information captured chosen modes. Due to the highly nonlinear nature of the Navier-Stokes equations, the process of choosing an 'appropriate' set of modes from the simulation or experimental data is non-trivial. Recent work indicates that modal decompositions computed using a sparse coding approach yield multi-scale modes that provide improved low-order models compared to the commonly used proper orthogonal *** study seeks to use energy components analysis to develop a deeper understanding of the improved model performance with sparse modes. In addition, a to greedy search-based sparse coding algorithm is developed for basis extraction. The analysis is performed on two canonical problems of incompressible flow inside a lid-driven cavity and past a stationary cylinder. Results indicate that there is a direct link between the presense of multi-scale features in the reduced set of modes, balance between production and dissipation of energy, and reduced order model performance.
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