4 research outputs found
Intelligent Feature Extraction, Data Fusion and Detection of Concrete Bridge Cracks: Current Development and Challenges
As a common appearance defect of concrete bridges, cracks are important
indices for bridge structure health assessment. Although there has been much
research on crack identification, research on the evolution mechanism of bridge
cracks is still far from practical applications. In this paper, the
state-of-the-art research on intelligent theories and methodologies for
intelligent feature extraction, data fusion and crack detection based on
data-driven approaches is comprehensively reviewed. The research is discussed
from three aspects: the feature extraction level of the multimodal parameters
of bridge cracks, the description level and the diagnosis level of the bridge
crack damage states. We focus on previous research concerning the quantitative
characterization problems of multimodal parameters of bridge cracks and their
implementation in crack identification, while highlighting some of their major
drawbacks. In addition, the current challenges and potential future research
directions are discussed.Comment: Published at Intelligence & Robotics; Its copyright belongs to
author
Physicsâconstrained nonâGaussian probabilistic learning on manifolds
International audienceAn extension of the probabilistic learning on manifolds (PLoM), recently introduced by the authors, has been presented: In addition to the initial data set given for performing the probabilistic learning, constraints are given, which correspond to statistics of experiments or of physical models. We consider a non-Gaussian random vector whose unknown probability distribution has to satisfy constraints. The method consists in constructing a generator using the PLoM and the classical Kullback-Leibler minimum cross-entropy principle. The resulting optimization problem is reformulated using Lagrange multipliers associated with the constraints. The optimal solution of the Lagrange multipliers is computed using an efficient iterative algorithm. At each iteration, the Markov chainMonte Carlo algorithm developed for the PLoM is used, consisting in solving an ItĂŽ stochastic differential equation that is projected on a diffusion-maps basis. The method and the algorithm are efficient and allow the construction ofprobabilistic models for high-dimensional problems from small initial data sets and for which an arbitrary number of constraints are specified. The first application is sufficiently simple in order to be easily reproduced. The second one is relative to a stochastic elliptic boundary value problem in high dimension
Broad Learning System Based on Maximum Correntropy Criterion
As an effective and efficient discriminative learning method, Broad Learning
System (BLS) has received increasing attention due to its outstanding
performance in various regression and classification problems. However, the
standard BLS is derived under the minimum mean square error (MMSE) criterion,
which is, of course, not always a good choice due to its sensitivity to
outliers. To enhance the robustness of BLS, we propose in this work to adopt
the maximum correntropy criterion (MCC) to train the output weights, obtaining
a correntropy based broad learning system (C-BLS). Thanks to the inherent
superiorities of MCC, the proposed C-BLS is expected to achieve excellent
robustness to outliers while maintaining the original performance of the
standard BLS in Gaussian or noise-free environment. In addition, three
alternative incremental learning algorithms, derived from a weighted
regularized least-squares solution rather than pseudoinverse formula, for C-BLS
are developed.With the incremental learning algorithms, the system can be
updated quickly without the entire retraining process from the beginning, when
some new samples arrive or the network deems to be expanded. Experiments on
various regression and classification datasets are reported to demonstrate the
desirable performance of the new methods