scholarly journals Semisupervised Association Learning Based on Partial Differential Equations for Sparse Representation of Image Class Attributes

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Wei Song ◽  
Guang Hu ◽  
Liuqing OuYang ◽  
Zhenjie Zhu

Semisupervised learning is an idea that addresses how to use a large number of unlabeled samples and a limited number of labeled samples to learn decision knowledge together. In this paper, we propose a multitask multiview semisupervised learning model based on partial differential equation random field and Hilbert independent standard probability image genus attribute model, i.e., shared semantics. In the framework of the image-like genus attribute model, data from different data sources are generated by their shared hidden space representation. Different from the traditional model, this paper uses the Hilbert independence criterion to inscribe the shared relationship of hidden expressions. Meanwhile, to exploit the correlations between labels in the label space as well, this paper uses the partial differential equation random field to inscribe the correlations between different kinds of labels in the label space and the correlations between hidden features and labels. Using the variational expectation-maximization algorithm, the whole generative process model can be inferred. To verify the effectiveness of the model, two artificial datasets and three real datasets are tested in this paper, and the experimental results verify the effectiveness of the algorithm in the paper. On the one hand, it not only improves the classification accuracy of the multiclassification problem and the multilabel problem; it also outputs the association structure between different kinds of labels and between hidden features and labels.

Author(s):  
Adamu Yebi ◽  
Beshah Ayalew

This paper proposes a feedback control system for curing thick film resins using ultraviolet (UV) radiation. A model-based distributed parameter control scheme is constructed for addressing the challenge of achieving through cure while reducing temperature gradients in thick films in composite laminates. The UV curing process is modeled with a parabolic partial differential equation (PDE) that includes an in-domain radiative input along with a nonlinear spatial attenuation function. The control problem is first cast as a distributed temperature trajectory-tracking problem where only surface temperature measurements are available. By transforming the original process model to an equivalent boundary input problem, backstepping boundary PDE control designs are applied to explicitly obtain both the controller and the observer gain kernels. Offline optimization may be used to generate the desired temperature trajectory, considering quality constraints such as prespecified spatial gradients and UV source limitations. The workings and the performance of the proposed control scheme are illustrated through simulations of the process model. It is shown that feedforward compensation can be added to achieve improved tracking with the PDE controller in the presence of measurement noise and other process disturbances.


2020 ◽  
pp. 2150028
Author(s):  
Xuebin Lü ◽  
Wanyang Dai

We study a non-conservation second-order stochastic partial differential equation (SPDE) driven by multi-parameter anisotropic fractional Lévy noise (AFLN) and under different initial and/or boundary conditions. It includes the time-dependent linear heat equation and quasi-linear heat equation under the fractional noise as special cases. Unique existence and expressions of solution to the equation are proved and constructed. An AFLN is defined as the derivative of an anisotropic fractional Lévy random field (AFLRF) in certain sense. Comparing with existing noise systems, our non-Gaussian fractional noises are essentially observed from random disturbances on system accelerations rather than from those on system moving velocities. In the process of proving our claims, there are three folds. First, we consider the AFLRF as the generalized functional of sample paths of a pure jump Lévy process. Second, we build Skorohod integration with respect to the AFLN by white noise approach. Third, by combining this noise analysis method with the conventional PDE solution techniques, we provide solid proofs for our claims.


2000 ◽  
Vol 42 (3-4) ◽  
pp. 417-422 ◽  
Author(s):  
T.Y. Pai ◽  
C.F. Ouyang ◽  
Y.C. Liao ◽  
H.G. Leu

Oxygen diffused to water in gravity sewer pipes was studied in a 21 m long, 0.15 m diameter model sewer. At first, the sodium sulfide was added into the clean water to deoxygenate, then the pump was started to recirculate the water and the deoxygenated water was reaerated. The dissolved oxygen microelectrode was installed to measure the dissolved oxygen concentrations varied with flow velocity, time and depth. The dissolved oxygen concentration profiles were constructed and observed. The partial differential equation diffusion model that considered Fick's law including the molecular diffusion term and eddy diffusion term were derived. The analytic solution of the partial differential equation was used to determine the diffusivities by the method of nonlinear regression. The diffusivity values for the oxygen transfer was found to be a function of molecular diffusion, eddy diffusion and flow velocity.


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