The effectiveness of non-parametric methods for regression comes at the price of high computational complexity. In fact, these methods scale as O(N 3 ), where N is the number of available data points. One possible opt...
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The effectiveness of non-parametric methods for regression comes at the price of high computational complexity. In fact, these methods scale as O(N 3 ), where N is the number of available data points. One possible option to address this issue consists in introducing a set of fictitious (pseudo-) inputs of size M ≪ N such that the computational effort is reduced to O(M 2 N). To estimate hyper-parameters and pseudo-inputs, a non-convex optimization problem needs to be solved. As opposed to the conventional gradient-based approach used in the literature, this paper proposes a stochastic scheme leveraging Markov Chain Monte Carlo methods. Numerical comparisons show that the latter returns a more efficient set of pseudo-inputs, leading to a superior performance in terms of mean squared error.
Electroencephalography(EEG) contains a wealth of information, including neuron activity, allowing for a partial understanding of the brain's state. As a reliable tool, EEG, combined with deep neural networks, has ...
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ISBN:
(数字)9789887581581
ISBN:
(纸本)9798350366907
Electroencephalography(EEG) contains a wealth of information, including neuron activity, allowing for a partial understanding of the brain's state. As a reliable tool, EEG, combined with deep neural networks, has been increasingly utilized to assist in the detection of depression and has achieved satisfactory results. However, there are still some limitations in the current models. Firstly, it is worth noting that many existing models are binary classification models. These models can determine whether a subject is depressed or not, but they lack the capability to differentiate the severity of depression. Besides, the variations in EEG signals among various individuals have not been thoroughly taken into account, leading to subpar performance when applying the trained model to new subjects. To address the aforementioned issues, we suggest implementing a multi-classification model that utilizes a graph convolutional neural network(GCN) to identify levels of depression. Additionally,to mitigate the problem of imbalanced samples in multi-classification tasks, we introduce a penalty coefficient for the smaller categories. At the same time, the issue of signal discrepancies among subjects was taken into account, leading to the introduction of the domain generalization module. Finally, the depression level identification task on the MODMA and PRED+CT dataset achieved an accuracy of 75.47% and 77.97% respectively, surpassing the performance of the state-of-the-art(SOTA) model. In addition, numerous ablation experiments were conducted to validate the efficacy of each module.
The energy system is becoming increasingly complex due to a surge of low carbon technologies driven by an intensified trend of carbon mitigation strategies. How to develop the energy technologies in a smooth and rapid...
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The emission of carbon oxides(COX), nitrogen oxides(NOX), sulfur compounds, and volatile organic compounds(VOCs) from vehicles has significantly impacted the air quality, thus posing threats to the environmental...
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ISBN:
(数字)9789887581581
ISBN:
(纸本)9798350366907
The emission of carbon oxides(COX), nitrogen oxides(NOX), sulfur compounds, and volatile organic compounds(VOCs) from vehicles has significantly impacted the air quality, thus posing threats to the environmental resources and human health. This work presents the development of a non-dispersive infrared(NDIR) multi-gas detection system featuring three broadband light sources, a sealed gas chamber, and three multi-channel pyroelectric detectors with a response time shorter than 32 ms. The proposed system is used for constructing an odor dataset comprising five target gases, including carbon dioxide(CO),carbon monoxide(CO), nitric oxide(NO), sulfur dioxide(SO), and propane(CH). We perform odor recognition experiments using the traditional machine learning methods, as well as one-dimensional convolutional neural network(1D-CNN) and depthwise separable convolutional neural network(DS-CNN). The results show that the proposed DS-CNN model achieves an accuracy of 94.75% in recognizing different odors, thus outperforming other classification algorithms. This work demonstrates that the proposed detection system exhibits rapid response and precise recognition, thus establishing it as an effective approach for analyzing the primary components of automobile exhaust.
Saccharide production is critical to the development of biotechnology in the field of food and *** extraction of saccharide from biomass-based hydrolysate mixtures has become a trend due to low cost and abundant bioma...
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Saccharide production is critical to the development of biotechnology in the field of food and *** extraction of saccharide from biomass-based hydrolysate mixtures has become a trend due to low cost and abundant biomass *** to conventional methods of fractionation and recovery of saccharides,nanofiltration(NF)has received considerable attention in recent decades because of its high selectivity and low energy consumption and environmental *** this review the advantages and challenges of NF based technology in the separation of saccharides are critically *** membrane processes,i.e.,combining NF with ultrafiltration,can complement each other to provide an efficient approach for removal of unwanted solutes to obtain higher purity ***,use of NF membrane separation technology is limited due to irreversible membrane fouling that results in high capital and operating *** development of NF membrane technology should therefore focus on improving material stability,antifouling ability and saccharide targeting selectivity,as well as on engineering aspects such as process optimisation and membrane module design.
Si anode is of paramount importance for advanced energy-dense lithium-ion batteries(LIBs).However,the large volume change as well as stress generates during its lithiation-delithiation process poses a great challenge ...
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Si anode is of paramount importance for advanced energy-dense lithium-ion batteries(LIBs).However,the large volume change as well as stress generates during its lithiation-delithiation process poses a great challenge to the long-term cycling and hindering its *** this work,a composite binder is prepared with a soft component,guar gum(GG),and a rigid linear polymer,anionic polyacrylamide(APAM).Rich hydroxy,carboxyl,and amide groups on the polymer chains not only enable intermolecular crosslinking to form a web-like binder,A2G1,but also realize strong chemical binding as well as physical encapsulating to Si *** resultant electrode shows limited thickness change of merely 9%on lithiation and almost recovers its original thickness on *** demonstrates high reversible capacity of 2104.3 mAh g^(-1)after 100 cycles at a current density of 1800 mA g^(-1),and in constant capacity(1000 mAh g^(-1))test,it also shows a long life of 392 ***,this soft-hard combining web-like binder illustrates its great potential in the future applications.
The implementation of synthetic polymer membranes in gas separations,ranging from natural gas sweetening,hydrogen separation,helium recovery,carbon capture,oxygen/nitrogen enrichment,etc.,has stimulated the vigorous d...
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The implementation of synthetic polymer membranes in gas separations,ranging from natural gas sweetening,hydrogen separation,helium recovery,carbon capture,oxygen/nitrogen enrichment,etc.,has stimulated the vigorous development of high-performance membrane ***,size-sieving types of synthetic polymer membranes are frequently subject to a trade-off between permeability and selectivity,primarily due to the lack of ability to boost fractional free volume while simultaneously controlling the micropore size ***,we review recent research progress on microporosity manipulation in high-free-volume polymeric gas separation membranes and their gas separation performance,with an emphasis on membranes with hourglass-shaped or bimodally distributed ***-of-the-art strategies to construct tailorable and hierarchically microporous structures,microporosity characterization,and microcavity architecture that govern gas separation performance are systematically summarized.
Surface roughness plays an important role which affects the fatigue performance of additively manufactured metal components. Surface roughness generally contains micro-notches which form stress concentration and signi...
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The distributed nonconvex optimization problem of minimizing a global cost function formed by a sum of n local cost functions by using local information exchange is *** problem is an important component of many machin...
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The distributed nonconvex optimization problem of minimizing a global cost function formed by a sum of n local cost functions by using local information exchange is *** problem is an important component of many machine learning techniques with data parallelism,such as deep learning and federated *** propose a distributed primal-dual stochastic gradient descent(SGD)algorithm,suitable for arbitrarily connected communication networks and any smooth(possibly nonconvex)cost *** show that the proposed algorithm achieves the linear speedup convergence rate O(1/(√nT))for general nonconvex cost functions and the linear speedup convergence rate O(1/(nT)) when the global cost function satisfies the Polyak-Lojasiewicz(P-L)condition,where T is the total number of *** also show that the output of the proposed algorithm with constant parameters linearly converges to a neighborhood of a global *** demonstrate through numerical experiments the efficiency of our algorithm in comparison with the baseline centralized SGD and recently proposed distributed SGD algorithms.
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