We consider the blind separation of source layers from superimposed mixtures thereof, involving unknown motions and unknown mixing coefficients of layers in each mixture. Previous blind separation approaches for such ...
详细信息
We consider the blind separation of source layers from superimposed mixtures thereof, involving unknown motions and unknown mixing coefficients of layers in each mixture. Previous blind separation approaches for such problems assume motions to be uniform translations, and hence are limited for real world applications. In this paper, we develop a sparse blind separation algorithm to estimate both parameterized motions and mixing coefficients. Then, a novel reconstruction approach is presented to recover all layers, by utilizing not only the mixing model but also the statistical properties of natural images. The whole method can handle more general motions than translations, including scalings, rotations and other transformations. In addition, the number of layers is automatically identified, and all layers can be recovered even in the under-determined case where mixtures are fewer than layers. The effectiveness of this technology is shown in the experiments on two simulated mixtures of four layers, real photos containing transparency and reflections, and real crossfade images from videos.
In this paper, we propose a fast mean-field method called LHMF to handle probabilistic models of large-scale data in high dimensional space. By using diffusion map locally linear embedding method which is a non-linear...
详细信息
In this paper, we propose a fast mean-field method called LHMF to handle probabilistic models of large-scale data in high dimensional space. By using diffusion map locally linear embedding method which is a non-linear dimensionality reduction method, we first embed the high dimensional data into a low dimensional space. Then we construct a coarse-grained graph which preserves the spectral properties of original weighted graph in the high dimensional space by clustering. A new spin model is defined in the diffusion space and the geometric centroids of clusters represent variables in the new spin model. The calculation demand of mean-field methods can be reduced greatly on the coarse-grained spin model. The final marginal moments of original variables are derived from the states of geometric centroids by using geometric harmonics. We first tested the proposed method on the MNIST hand-written digits dataset. Experimental results show that the LHMF method is competent with consistency approach, a state-of-the-art semi-supervised learning method. Then we applied the proposed method to a large-scale colonic polyp dataset from computed tomography (CT) scans. Free-response operator characteristic analysis shows that our method achieves higher sensitivity with lower false positive rate compared with support vector machines.
Inverse kinematic motion planning of redundant manipulators by using recurrent neural networks in the presence of obstacles and uncertainties is a real-time nonlinear optimization problem. To tackle this problem, two ...
详细信息
Inverse kinematic motion planning of redundant manipulators by using recurrent neural networks in the presence of obstacles and uncertainties is a real-time nonlinear optimization problem. To tackle this problem, two subproblems should be resolved in real time. One is the determination of critical points on a given manipulator closest to obstacles, and the other is the computation of joint velocities of the manipulator which can direct the manipulator following a desired trajectory and away from obstacles if it is getting close to them. Different from our previous approaches where the critical points on the manipulator were assumed to be known, these points are to be computed by using a recurrent neural network in the paper. A time-varying quadratic programming problem is formulated for avoiding polyhedral obstacles. In view that the problem is not strictly convex, an existing recurrent neural network, general projection neural network, is applied for solving it. By introducing a velocity smoothing technique into our previous quadratic programming formulation of the joint velocity assignment problem, a recently developed recurrent neural network, improved dual neural network, is proposed to solve it, which features lower structural complexity compared with existing neural networks. Moreover, The effectiveness of the proposed neural networks is demonstrated by simulations on the Mitsubishi PA10-7C manipulator.
Home automationsystems based on wireless sensor/actuator networks are characterized by diversity of node power sources, limited computational power, and mobility. We propose a routing protocol that fully uses the loc...
详细信息
Home automationsystems based on wireless sensor/actuator networks are characterized by diversity of node power sources, limited computational power, and mobility. We propose a routing protocol that fully uses the location of static nodes to limit the search for a route to a small zone based on the analysis of characteristics and requirements. The calculation of two different kinds of zone and the route discovery procedure are described in this paper. According to the environment of home automation, we compared the performance of our routing protocols with the ad-hoc on-demand distance-vector protocol using simulation and gave suggestions for zone selection. Simulation results showed that our routing protocol dramatically reduced the routing overhead and increased the reliability.
We address robust stabilization problem for networked control systems with nonlinear uncertainties and packet losses by modelling such systems as a class of uncertain switched systems. Based on theories on switched Ly...
详细信息
ISBN:
(纸本)9781424445233
We address robust stabilization problem for networked control systems with nonlinear uncertainties and packet losses by modelling such systems as a class of uncertain switched systems. Based on theories on switched Lyapunov functions, we derive the robustly stabilizing conditions for state feedback stabilization and design packet-loss dependent controllers by solving some matrix inequalities. A numerical example and some simulations are worked out to demonstrate the effectiveness of the proposed design method.
Interactive network traffic replay is the newest method for testing and evaluation of network devices such as Firewalls, IPSes, routers, switches, etc. Currently state-checking method is used for interactive TCP traff...
详细信息
Interactive network traffic replay is the newest method for testing and evaluation of network devices such as Firewalls, IPSes, routers, switches, etc. Currently state-checking method is used for interactive TCP traffic replay. This paper proposes a new method for interactive TCP traffic replay which is based on the balance status between transmitted and received packets. By checking the balance conditions before sending out TCP packets, the method can significantly reduce the cost of state-checking and enhance the replay performance. The authors made a comparison on the differences of replay methods when introducing the balance mechanism. The efficiency of the method is also investigated and evaluated from aspects of a single TCP session, multi-session traffic, packet losses and latency. Experimental results show that the method outperforms the original state-checking method when replaying actual TCP traffics.
In some real-world classification tasks, the classifier may be trained on a data set which does not reflect the class distribution of the real data set. Such sampling bias or virtual concept drift may seriously affect...
详细信息
In some real-world classification tasks, the classifier may be trained on a data set which does not reflect the class distribution of the real data set. Such sampling bias or virtual concept drift may seriously affect the classification accuracy. Previous researches on this topic mainly concern classifiers with explicit a posteriori probabilities output. There has been a framework to adjust the original classifier using Expectation Maximization (EM) algorithm for such classifiers. The margin based classifier Support Vector Machine (SVM), has not been studied under this framework because of the lack of probabilistic output. In this paper, we discuss the probabilistic output of SVM and propose a Gaussian Mixture Model (GMM) to approximate the class conditional distribution of the margin so as to adjust the classifier using the EM framework. Experimental results on standard machine learning data sets show that the proposed algorithm can improve the classification accuracy on most of these problems. It performs especially well on those data sets with low classification accuracy.
暂无评论