Photograph aesthetical evaluation has been widely investigated in these decades. For fine-granularity aesthetic quality prediction, a novel aesthetics classifier based on improved artificial neural network combined wi...
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Photograph aesthetical evaluation has been widely investigated in these decades. For fine-granularity aesthetic quality prediction, a novel aesthetics classifier based on improved artificial neural network combined with an autoencoder technique is presented. First, we download large consumer photographic images from a well-known online photograph portal. Then, we extract 56 features normalized to 0-1 and train the networks with photographs of high and low ratings to test the quality of photos. Experimental results show that the accuracy of classification is above 86.67%, which is better than all state-of-the-art methods. Meanwhile, it is observed from experiments that the extracted features are consistent with the humans' visual perception systems. (C) 2015 Elsevier B.V. All rights reserved.
Hyperspectral unmixing, which estimates end-members and their corresponding abundance fractions simultaneously, is an important task for hyperspectral applications. In this article, we propose a new autoencoder-based ...
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Hyperspectral unmixing, which estimates end-members and their corresponding abundance fractions simultaneously, is an important task for hyperspectral applications. In this article, we propose a new autoencoder-based hyperspectral unmixing model with three novel components. First, we propose a new sparse prior to abundance maps. The proposed prior, called orthogonal sparse prior (OSP), is based on the observations that different abundance maps are close to orthogonal because, generally, no more than two end-members are mixed within one pixel. As opposed to the conventional norm-based sparse prior that assumes the abundance maps are independent, the proposed OSP explores the orthogonality between the abundance maps. Second, we propose the hyper-Laplacian loss to model the reconstruction error. The key observation is that the reconstruction error distribution usually has a heavy-tailed shape, which is better modeled by the hyper-Laplacian distribution rather than the commonly used Gaussian distribution. Third, to ease the side effect of outliers for end-member initializations, we develop a data-driven approach to detect outliers from the raw hyperspectral images. Extensive experiments on both synthetic and real-world data sets show that the proposed method significantly and consistently outperforms the compared state-of-the-art methods, with up to more than 50% improvements.
As an unsupervised learning method, the autoencoder (AE) plays a very important role in model pre-training. However, the current AEs pre-training methods are still faced with the problems of not being able to reconstr...
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As an unsupervised learning method, the autoencoder (AE) plays a very important role in model pre-training. However, the current AEs pre-training methods are still faced with the problems of not being able to reconstruct pictures better and mining deeper features. In this paper, we come up with a new AE, overall improved autoencoder (OIAE). Its main contribution is twofold: Wasserstein Generative Adversarial Networks (WGAN) is used to study the relationship between AEs reconstruction ability and pre-training performance and a regularization method is proposed to enable the autoencoder to learn discriminative features. We set up ablation experiments to prove the effectiveness of our two improvements and OIAE and compare them with baseline. The classification accuracy of the OIAE pre-trained classification network improved by 0.74% on the basic dataset and 16.44% on the more difficult dataset. These promising results demonstrate the effectiveness of our method in AEs pre-training tasks.
The aim of this correspondence is two-fold: (i) to assess the performance of a conventional wireless system jointly subject to short-term fading (alpha-mu model), long-term fading (Gamma model), path loss (power law d...
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The aim of this correspondence is two-fold: (i) to assess the performance of a conventional wireless system jointly subject to short-term fading (alpha-mu model), long-term fading (Gamma model), path loss (power law decay), and mobility (random waypoint model) through analytical formulations;and (ii) to assess the performance of a non-conventional wireless system subject to the same conditions as before but with the transmission-medium-receiving chain replaced by an autoencoder using deep neural networks. The paper derives novel closed-form expressions for the probability density function, cumulative distribution function, and moment-generating function of the received signal. The performance analysis under investigation concerns outage probability, symbol error probability, asymptotic analyses, and channel capacity, all in closed-form formulations. In addition to showing that mobility has a beneficial effect on the overall mean performance, this work also illustrates that the said unconventional system may achieve as good a performance of the conventional one.
The lack of an efficient compression model remains a challenge for the wireless transmission of gearbox data in non-contact gear fault diagnosis problems. In this paper, we present a signal-adaptive asymmetrical autoe...
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The lack of an efficient compression model remains a challenge for the wireless transmission of gearbox data in non-contact gear fault diagnosis problems. In this paper, we present a signal-adaptive asymmetrical autoencoder with a transform domain layer to compress sensor signals. First, a new discrete cosine Stockwell transform (DCST) layer is introduced to replace linear layers in a multi-layer autoencoder. A trainable filter is implemented in the DCST domain by utilizing the multiplication property of the convolution. A trainable hard-thresholding layer is applied to reduce redundant data in the DCST layer to make the feature map sparse. In comparison to the linear layer, the DCST layer reduces the number of trainable parameters and improves the accuracy of data reconstruction. Second, training the autoencoder with a sparsifying DCST layer only requires a small number of datasets. The proposed method is superior to other autoencoder-based methods on the University of Connecticut (UoC) and Southeast University (SEU) gearbox datasets, as the average quality score is improved by 2.00% at the lowest and 32.35% at the highest with a limited number of training samples.
In the task of multi-label classification, it is a key challenge to determine the correlation between labels. One solution to this is the Target Embedding autoencoder (TEA), but most TEA-based frameworks have numerous...
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In the task of multi-label classification, it is a key challenge to determine the correlation between labels. One solution to this is the Target Embedding autoencoder (TEA), but most TEA-based frameworks have numerous parameters, large models, and high complexity, which makes it difficult to deal with the problem of large-scale learning. To address this issue, we provide a Target Embedding autoencoder framework based on Knowledge Distillation (KD-TEA) that compresses a Teacher model with large parameters into a small Student model through knowledge distillation. Specifically, KD-TEA transfers the dark knowledge learned from the Teacher model to the Student model. The dark knowledge can provide effective regularization to alleviate the over-fitting problem in the training process, thereby enhancing the generalization ability of the Student model, and better completing the multi-label task. In order to make the Student model learn the knowledge of the Teacher model directly, we improve the distillation loss: KD-TEA uses MSE loss instead of KL divergence loss to improve the performance of the model in multi-label tasks. Experiments on multiple datasets show that our KD-TEA framework is superior to the most advanced multi-label classification methods in both performance and efficiency.
Electrocardiography is essential for the early diagnosis and treatment of heart diseases, as undiagnosed heart diseases can lead to unfortunate outcomes such as patient loss. autoencoder-based models have been used in...
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Electrocardiography is essential for the early diagnosis and treatment of heart diseases, as undiagnosed heart diseases can lead to unfortunate outcomes such as patient loss. autoencoder-based models have been used in the literature for ECG heartbeat classification. However, these models usually use the autoencoder in the feature extraction stage. The features obtained from the previous step are passed through a classifier for training. This indicates that the training procedure occurs in two phases. In this study, we performed autoencoder and classifier training simultaneously. This way, the network learned to minimize the overall loss while correctly reconstructing the input and extracting relevant features from the input data that are useful for the classification task. Such an approach has yet to be seen in the literature for ECG detection. The classification of six heartbeats (normal beat, left bundle branch block beat, right bundle branch block beat, premature ventricular contraction, atrial premature beat, and paced beat) obtained from the MIT-BIH dataset was performed using a convolutional autoencoder with an integrated classifier. The classification accuracy obtained in the test was found to be 99.99%.
Existing deep learning methods for clustering high-dimensional data perform feature selection and clustering separately, which can result in the exclusion of some important features for clustering. In this paper, we p...
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Existing deep learning methods for clustering high-dimensional data perform feature selection and clustering separately, which can result in the exclusion of some important features for clustering. In this paper, we propose a method that performs deep clustering and feature selection simultaneously by inserting a concrete selector layer between the input layer and the first encoder layer of a modified autoencoder. The concrete selector layer performs feature selection, while the modified autoencoder performs clustering in the latent space by incorporating K-means loss and inter-cluster distances. The proposed method, called the K-concrete autoencoder, selects features important for clustering and uses only the selected features to learn K-means-friendly latent representations of the data. Moreover, we propose an extension of the K-concrete autoencoder to provide relative importance of each selected feature. We demonstrate the effectiveness of the proposed method using simulated and real datasets.
The hash index plays an important role in improving query efficiency in databases. Because traditional hash algorithms cannot use the original data distribution, there is often a high collision rate in large-scale dat...
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The hash index plays an important role in improving query efficiency in databases. Because traditional hash algorithms cannot use the original data distribution, there is often a high collision rate in large-scale datasets. Additionally, some traditional hashing algorithms are data-dependent and cannot be accelerated in parallel. The learned index provides a new method for index design in data management systems. The key idea of the learned index is to consider the index as a model that can be learned. In this paper, we propose a learning hash algorithm based on a shallow autoencoder that can make full use of the original data characteristics and take advantage of the parallelism of matrix operations. Therefore, compared with traditional hash functions, the proposed method has a lower collision rate and higher efficiency. Finally, we verify the effectiveness of the proposed method through a series of experiments on synthetic datasets and real datasets. Experimental results show that the proposed hash algorithm has considerable advantages in reducing the collision rate and computing time while improving the retrieval efficiency.
Remaining useful life (RUL) prediction plays a significant role in the prognostic and health management (PHM) of rotating machineries. A good health indicator (HI) can ensure the accuracy and reliability of RUL predic...
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Remaining useful life (RUL) prediction plays a significant role in the prognostic and health management (PHM) of rotating machineries. A good health indicator (HI) can ensure the accuracy and reliability of RUL prediction. However, numerous existing deep learning-based HI construction approaches rely heavily on the prior knowledge, and they are difficult to capture the key information in the process of machinery degradation from raw signals, thereby affecting the performance of RUL prediction. To tackle the aforementioned problem, a new supervised multi-head self-attention autoencoder (SMSAE) is proposed for extracting the HI that effectively reflects the degraded state of rotating machinery. By embedding the multi-head self-attention (MS) module into autoencoder and imposing the constraint of power function-type labels on the hidden variable, SMSAE can directly extract the HIs from raw vibration signals. As the current HI evaluation indexes don't consider the global monotonicity and variation law of HI, two improved monotonicity and robustness indexes are designed for the better evaluation of HI. With the proposed HI, a two-stage residual life prediction framework based on similarity is developed. Extensive experiments have been performed on an actual wind turbine gearbox bearing dataset and a well-known open commercial modular aero-propulsion system simulation (C-MAPSS) dataset. The comparative results verify that the constructed SMSAE HI has better comprehensive performance than the typical HIs, and the proposed prediction method is competitive with the state-of-the-art methods.
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