Machine learning approaches can build a computational model to predict cognitive workload levels by using electroencephalogram (EEG) feature inputs at the same time instant. However, when the EEG signals are recorded ...
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Machine learning approaches can build a computational model to predict cognitive workload levels by using electroencephalogram (EEG) feature inputs at the same time instant. However, when the EEG signals are recorded on different people, the accuracy of such a model could be impaired due to its incapability of fitting varied statistical distributions across different individuals. To this end, we propose an individual-independent workload estimator, a cascade ensemble of multilayer autoencoders to tackle the individual difference within the EEG features. It could assess the workload levels of an unseen subject by adapting the EEG data recorded from non-overlapped existing subjects. We first construct a deep stacked denoising autoencoder to abstract EEG features from a specific individual. Its shallow weights are optimized with individual-specific geometrical information of the features. Then, to find generalizable feature properties, we introduce Q-statistics to measure the independence between base learners. Finally, a regularized extreme learning machine is used as a cascade metaclassifier to fuse and filter high-level EEG abstractions and determine workload levels. We employ databases from two different experiments to validate our approach. The proposed framework can lead to acceptable accuracy and computational complexity compared to several existing workload classifiers.
作者:
Yu, JianboTongji Univ
Sch Mech Engn 4800 CaoAn Rd Shanghai 201804 Peoples R China
Vibration signals are widely used as an effective way to fulfill gearbox fault diagnosis. However, it is quite challenging to extract effective fault features from noisy vibration signals and then to construct a relia...
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Vibration signals are widely used as an effective way to fulfill gearbox fault diagnosis. However, it is quite challenging to extract effective fault features from noisy vibration signals and then to construct a reliable fault diagnosis model. This paper proposes a selective stacked denoising autoencoders (SDAE) with negative correlation learning (NCL) (SSDAE-NCL) for gearbox fault diagnosis. The component SDAEs are firstly constructed to extract effective fault features from vibration signals in the unsupervised-learning phase of SSDAE-NCL. Based on the extracted features, NCL is used to fine-tune the SDAE components to construct component classifiers in the supervised-learning phase of SSDAE-NCL. Finally, a selective ensemble is finished based on these divers and accurate component SDAEs for gearbox fault diagnosis. The motivation for developing ensemble of deep neural networks (DNNs) is that they can achieve higher accuracy and applicability than single component in machinery fault diagnosis. Furthermore, it can make an overall ensemble model easy to use in real cases for users, because it does not need too much prior knowledge about setup of a DNN model. The effectiveness of this SSDAE-NCL-based fault diagnosis method has been verified by experimental results on the vibration signal data from a gearbox test rig. The results illustrate that SSDAE-NCL learns effective discriminative features from vibration signals and achieves the better diagnosis accuracy in comparison with those typical DNNs (e.g.;SDAE, deep belief network (DBN)). (C) 2019 The Author. Published by Elsevier B.V.
The collaborative filtering method is widely used in the traditional recommendation system. The collaborative filtering method based on matrix factorization treats the user's preference for the item as a linear co...
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The collaborative filtering method is widely used in the traditional recommendation system. The collaborative filtering method based on matrix factorization treats the user's preference for the item as a linear combination of the user and the item latent vectors, and cannot learn a deeper feature representation. In addition, the cold start and data sparsity remain major problems for collaborative filtering. To tackle these problems, some scholars have proposed to use deep neural network to extract text information, but did not consider the impact of long-distance dependent information and key information on their models. In this paper, we propose a neural collaborative filtering recommender method that integrates user and item auxiliary information. This method fully integrates user-item rating information, user assistance information and item text assistance information for feature extraction. First, stackeddenoising Auto Encoder is used to extract user features, and Gated Recurrent Unit with auxiliary information is used to extract items' latent vectors, respectively. The attention mechanism is used to learn key information when extracting text features. Second, the latent vectors learned by deep learning techniques are used in multi-layer nonlinear networks to learn more abstract and deeper feature representations to predict user preferences. According to the verification results on the MovieLens data set, the proposed model outperforms other traditional approaches and deep learning models making it state of the art.
High-frequency market making is a liquidity-providing trading strategy that simultaneously generates many bids and asks for a security at ultra-low latency while maintaining a relatively neutral position. The strategy...
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ISBN:
(纸本)9798400704864
High-frequency market making is a liquidity-providing trading strategy that simultaneously generates many bids and asks for a security at ultra-low latency while maintaining a relatively neutral position. The strategy makes a profit from the bid-ask spread for every buy and sell transaction, against the risk of adverse selection, uncertain execution and inventory risk. We design realistic simulations of limit order markets and develop a high-frequency market making strategy in which agents process order book information to post the optimal price, order type and execution time. By introducing the Deep Hawkes process to the high-frequency market making strategy, we allow a feedback loop to be created between order arrival and the state of the limit order book, together with self- and cross-excitation effects. Our high-frequency market making strategy accounts for the cancellation of orders that influence order queue position, profitability, bid-ask spread and the value of the order. The experimental results show that our trading agent outperforms the baseline strategy, which uses a probability density estimate of the fundamental price. We investigate the effect of cancellations on market quality and the agent's profitability. We validate how closely the simulation framework approximates reality by reproducing stylised facts from the empirical analysis of the simulated order book data.
A deep learning intrusion detection algorithm based on stacked denoising autoencoder and extreme learning machine (SDA-ELM) is proposed to solve the problem that the traditional machine learning algorithm can't co...
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ISBN:
(数字)9783030794637
ISBN:
(纸本)9783030794620;9783030794637
A deep learning intrusion detection algorithm based on stacked denoising autoencoder and extreme learning machine (SDA-ELM) is proposed to solve the problem that the traditional machine learning algorithm can't cope with the classification of multisource heterogeneous network intrusion data. The algorithm use Dropout regularization to improve the SDA deep learning model, and the integration features of low dimensionality and high robustness are extracted. Then the model use ELM to carry out a supervised learning for the low dimension data to recognize the network attack. The algorithm combines the abstract feature extraction capability of SDA and the fast learning ability of ELM. The experimental results show that the SDA-ELM algorithm improves the accuracy of classification and the detection rate of small sample attacks, reduces the false alarm rate.
Accurate and reliable prediction of exhaust emissions is crucial for combustion optimization control and environmental protection. This study proposes a novel ensemble deep learning model for exhaust emissions (NOx an...
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Accurate and reliable prediction of exhaust emissions is crucial for combustion optimization control and environmental protection. This study proposes a novel ensemble deep learning model for exhaust emissions (NOx and CO2) prediction. In this ensemble learning model, the stacked denoising autoencoder is established to extract the deep features of flame images. Four forecasting engines include artificial neural network, extreme learning machine, support vector machine and least squares support vector machine are employed for preliminary prediction of NOx and CO2 emissions based on the extracted image deep features. After that, these preliminary predictions are combined by Gaussian process regression in a nonlinear manner to achieve a final prediction of the emissions. The effectiveness of the proposed ensemble deep learning model is evaluated through 4.2 MW heavy oil-fired boiler flame images. Experimental results suggest that the predictions are achieved from the four forecasting engines are inconsistent, however, an accurate prediction accuracy has been achieved through the proposed model. The proposed ensemble deep learning model not only provides accurate point prediction but also generates satisfactory confidence interval.
For line-commutated converter (LCC) based HVDC system, successive commutation failure (SCF) can result in continual cessations of power transmission or even forced blocking of the DC system. AC grid cascading failure ...
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For line-commutated converter (LCC) based HVDC system, successive commutation failure (SCF) can result in continual cessations of power transmission or even forced blocking of the DC system. AC grid cascading failure near inverters is an important reason for the SCF. The SCF probability is utilized to represent the impact of AC grid cascading failures on DC systems. This paper proposes a fast probability estimation method of SCF based on sequential importance sampling (SIS) and stacked denoising autoencoder (SDAE). Firstly, the probability estimation of SCF caused by cascading failures is transformed into a statistical analysis problem. Secondly, considering AC line failures have different impacts on DC system, a cascading failure sampling method based on SIS is presented to efficiently generate cascading failure samples and evaluate the SCF probability. Thirdly, SDAE based assessment network is established to quickly assess the impact of AC failures on SCF. Topology features related to AC grid structure and short-circuit fault locations are selected as inputs of the assessment network. Finally, real-life hybrid AC/DC grids are adopted to demonstrate the validity of the proposed method.
Bone age plays an important role in the scene of pediatrics and judicial identification, because the traditional bone age assessment is time-consuming, laborious and depends on the experience of physicians, the result...
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ISBN:
(纸本)9781450396899
Bone age plays an important role in the scene of pediatrics and judicial identification, because the traditional bone age assessment is time-consuming, laborious and depends on the experience of physicians, the results of artificial bone age assessment will vary from person to person. This paper has collected the X-ray image from a class A tertiary children's hospital, and presents the convolutional neural network suitable for China 05 bone age assessment. For the collected Chinese 3-16-year-old youth hand bone image, using the stacked denoising autoencoder (SDAE) combined with ResNet50, while reducing the noise of soft tissue and effectively improving the feature extraction ability of the model; Secondly, the 3×3 convolution in the ResNet50 residual block is replaced with a pyramid split attention (PSA) module to get the new model, fusion multi-level features of space and channel attention, adapt to re-define features; Presents the adaptive dual-channel pooling layer by combining the max pooling and average pooling; Use pre-excitement to speed up convergence and label smooth loss function to prevent the model from overfitting, and finally establish a deep learning classification model for China 05 bone age assessment. The experimental results show that the accuracy of ±1 year in this method reaches 93.22% of men, and 91.71% of women. The Mean Absolute Error (MAE) also decreases.
Deep learning plays an important role in soft sensors of industrial processes for the timely measurement of key quality variables. However, since sensors are often operated under noisy and nonstationary industrial con...
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Deep learning plays an important role in soft sensors of industrial processes for the timely measurement of key quality variables. However, since sensors are often operated under noisy and nonstationary industrial conditions, the collected industrial process data exhibit extreme complexity, which severely restricts the learning capacity and measurement accuracy of deep learning methods. In this paper, a novel denoising and multiscale residual deep network (DMRDN) is proposed for soft sensor modeling. Firstly, a stacked denoising autoencoder with level-aware attention is developed to denoise the process data, in which denoised features on different levels are learned and fused. Secondly, the denoised features are fed into multiscale residual convolutional neural network with scale-aware attention, which is designed to capture and fuse deep dynamic features from different scales. Finally, experiments were conducted on an industrial debutanizer column. The experimental results demonstrate that the proposed DMRDN greatly strengthens the learning ability and achieves better prediction performance compared with other methods.
Clinical data, such as evaluations, treatments, vital sign and lab test results, are usually observed and recorded in hospital systems. Making use of such data to help physicians to evaluate the mortality risk of in-h...
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ISBN:
(纸本)9781538668054
Clinical data, such as evaluations, treatments, vital sign and lab test results, are usually observed and recorded in hospital systems. Making use of such data to help physicians to evaluate the mortality risk of in-hospital patients provides an invaluable source of information that can ultimately help with improving healthcare services. In particular, quick and accurate predictions of mortality can be valuable for physicians who are making decisions about interventions. In this work we introduce the use of a predictive Deep Learning model to help evaluate the mortality risk for in-hospital patients. stacked denoising autoencoder (SDA) has been trained using a unique time-stamped dataset (King Abdullah International Research Center -KAIMRC) which is naturally imbalanced. The results are compared to those from common deep learning approaches, using different methods for data balancing. The proposed model demonstrated here aims to overcome the problem of imbalanced data, and outperforms common deep learning approaches with an accuracy of 77.13% for the Recall macro
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