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2017, 2017 International Artificial Intelligence and Data Processing Symposium (IDAP)
This paper introduces a novel deep recurrent support vector regressor (DRSVR) model for online regression. DRSVR model is constructed by a state equation followed by an output construction. The inner layer is actually a least squares support vector regressor (LS-SVR) of the states with an adaptive kernel function. In addition, an infinite impulse response (UR) filter is adopted in the model. LS-SVR and UR filter together constitute an intermediate layer which performs the recursive state update. Each internal state has a recurrency which is a function of the observed input-output data and the previous states. Hence, internal states track the temporal dependencies in the feature space. The outer layer is a linear combination of the states. The model parameters, including the Gaussian kernel width parameter, are updated simultaneously, that provides the model to capture the time-varying dynamics of the data quickly. Parameters are adaptively tuned using error-square minimization via c...
Journal of Soft Computing Paradigm
The nonlinear regression estimation issues are solved by successful application of a novel neural network technique termed as support vector machines (SVMs). Evaluation of recurrent neural networks (RNNs) can assist in pattern recognition of several real-time applications and reduce the pattern mismatch. This paper provides a robust prediction model for multiple applications. Traditionally, back-propagation algorithms were used for training RNN. This paper predict system reliability by applying SVM learning algorithm to RNN. Comparison of the proposed model is done with the existing systems for analysis of prediction performance. These results indicate that the performance of proposed system exceeds that of the existing ones.
IEEE Transactions on Circuits and Systems I: Fundamental Theory and Applications, 2000
The method of support vector machines (SVM's) has been developed for solving classification and static function approximation problems. In this paper we introduce SVM's within the context of recurrent neural networks. Instead of Vapnik's epsilon insensitive loss function, we consider a least squares version related to a cost function with equality constraints for a recurrent network. Essential features of SVM's remain, such as Mercer's condition and the fact that the output weights are a Lagrange multiplier weighted sum of the data points. The solution to recurrent least squares (LS-SVM's) is characterized by a set of nonlinear equations. Due to its high computational complexity, we focus on a limited case of assigning the squared error an infinitely large penalty factor with early stopping as a form of regularization. The effectiveness of the approach is demonstrated on trajectory learning of the double scroll attractor in Chua's circuit.
2008
This paper is about applying recurrent least squares support vector machines (LS-SVM) on three ESTSP08 competition datasets. Least squares support vector machines are used as nonlinear models in order to avoid local minima problems. Then prediction task is re-formulated as function approximation task. Recurrent LS-SVM uses nonlinear autoregressive exogenous (NARX) model to build nonlinear regressor, by estimating in each iteration the next output value, given the past output and input measurements.
IEEE Transactions on Neural Networks and Learning Systems, 2021
Recurrent neural networks (RNNs) are widely used for online regression due to their ability to generalize nonlinear temporal dependencies. As an RNN model, long short-term memory networks (LSTMs) are commonly preferred in practice, as these networks are capable of learning long-term dependencies while avoiding the vanishing gradient problem. However, due to their large number of parameters, training LSTMs requires considerably longer training time compared to simple RNNs (SRNNs). In this article, we achieve the online regression performance of LSTMs with SRNNs efficiently. To this end, we introduce a first-order training algorithm with a linear time complexity in the number of parameters. We show that when SRNNs are trained with our algorithm, they provide very similar regression performance with the LSTMs in two to three times shorter training time. We provide strong theoretical analysis to support our experimental results by providing regret bounds on the convergence rate of our algorithm. Through an extensive set of experiments, we verify our theoretical work and demonstrate significant performance improvements of our algorithm with respect to LSTMs and the other state-of-the-art learning models.
2007
Many approaches for obtaining systems with intelligent behavior are based on components that learn automatically from previous experience. The development of these learning techniques is the objective of the area of research known as machine learning. During the last decade, researchers have produced numerous and outstanding advances in this area, boosted by the successful application of machine learning techniques. This thesis presents one of this techniques, an online version of the algorithm for training the support vector machine for regression and also how it has been extended in order to be more flexible for the hyper parameter estimation. Furthermore the algorithm has been compared with a batch implementation
2002
This paper describes an on-line method for building ∈-insensitive support vector machines for regression as described in [12]. The method is an extension of the method developed by [1] for building incremental support vector machines for classification. Machines obtained by using this approach are equivalent to the ones obtained by applying exact methods like quadratic programming, but they are obtained more quickly and allow the incremental addition of new points, removal of existing points and update of target values for existing data. This development opens the application of SVM regression to areas such as on-line prediction of temporal series or generalization of value functions in reinforcement learning.
… , Systems Biology and …, 2009
Support vector machines are widely used for classification and regression tasks. They provide reliable static models, but their extension to the training of dynamic models is still an open problem. In the present paper, we describe Regularized Recurrent Support Vector Machines, which, in contrast to previous Recurrent Support Vector Machine, models, allow the design of dynamical models while retaining the built-in regularization mechanism present in Support Vector Machines. The principle is validated on academic examples; it is shown that the results compare favorably to those obtained by unregularized Recurrent Support Vector Machines and to regularized, partially recurrent Support Vector Machines.
2013
In this paper we describe a novel extension of the support vector machine, called the deep support vector machine (DSVM). The original SVM has a single layer with kernel functions and is therefore a shallow model. The DSVM can use an arbitrary number of layers, in which lower-level layers contain support vector machines that learn to extract relevant features from the input patterns or from the extracted features of one layer below. The highest level SVM performs the actual prediction using the highest-level extracted features as inputs. The system is trained by a simple gradient ascent learning rule on a min-max formulation of the optimization problem. A two-layer DSVM is compared to the regular SVM on ten regression datasets and the results show that the DSVM outperforms the SVM.
2019
Support Vector Machines, SVM, are one of the most popular machine learning models for supervised problems and have proved to achieve great performance in a wide broad of predicting tasks. However, they can suffer from scalability issues when working with large sample sizes, a common situation in the big data era. On the other hand, Deep Neural Networks (DNNs) can handle large datasets with greater ease and in this paper we propose Deep SVM models that combine the highly non-linear feature processing of DNNs with SVM loss functions. As we will show, these models can achieve performances similar to those of standard SVM while having a greater sample scalability.
ArXiv, 2020
We investigate online nonlinear regression with continually running recurrent neural network networks (RNNs), i.e., RNN-based online learning. For RNN-based online learning, we introduce an efficient first-order training algorithm that theoretically guarantees to converge to the optimum network parameters. Our algorithm is truly online such that it does not make any assumption on the learning environment to guarantee convergence. Through numerical simulations, we verify our theoretical results and illustrate significant performance improvements achieved by our algorithm with respect to the state-of-the-art RNN training methods.
2020
Deep Machine Learning takes place by adjusting the weights of deep neural networks – brain-like computational structures in order to optimize a given cost function. There exists a deep learning task where every neural model typically performs better. This paper explores optimization strategies for the GRU neural network such as dropout, gradient clipping and stacking ensembles of neural layers amongst others. The Recurrent Neural Networks (RNNs) are suited for classification and prediction problems based on time-series data. It has proven a challenging task for an ordinary RNN to learn long sequences leading to the invention of two other variants: Long Short Term Memory (LSTM) and the Gated Recurrent Unit (GRU). Whereas both of these compare well on most learning tasks, the structure of a LSTM is more complex with three gates and in effect has to compute and keep the cell state (Ct). This makes GRU simpler to implement and typically converges faster making it more appropriate for on...
Neural Processing Letters, 2005
A nonlinear black-box modeling approach using a state-space recurrent multilayer perceptron (RMLP) is considered in this paper. The unscented Kalman filter (UKF), which was proposed recently and is appropriate for state-space representation, is employed to train the RMLP. The UKF offers a derivative-free computation and an easy implementation, compared to the extended Kalman filter (EKF) widely used for training neural networks. In addition, the UKF has a fast convergence rate and an excellent capability of parameter estimation which are appropriate for online learning. Through modeling experiments of nonlinear systems, the effectiveness of the RMLP trained with the UKF is demonstrated.
… Intelligence in Robotics …, 2007
2020
Recurrent neural networks (RNNs) provide a powerful tool for online prediction in online partially observable problems. However, there are two primary issues one must overcome when training an RNN: the sensitivity of the learning algorithm’s performance to truncation length and and long training times. There are variety of strategies to improve training in RNNs, particularly with Backprop Through Time (BPTT) and by Real-Time Recurrent Learning. These strategies, however, are typically computationally expensive and focus computation on computing gradients back in time. In this work, we reformulate the RNN training objective to explicitly learn state vectors; this breaks the dependence across time and so avoids the need to estimate gradients far back in time. We show that for a fixed buffer of data, our algorithm—called Fixed Point Propagation (FPP)—is sound: it converges to a stationary point of the new objective. We investigate the empirical performance of our online FPP algorithm, ...
Physica D-nonlinear Phenomena, 1997
In feedforward networks, signals flow in only one direction without feedback. Applications in forecasting, signal processing and control require explicit treatment of dynamics. Feedforward networks can accommodate dynamics by including past input and target values in an augmented set of inputs. A much richer dynamic representation results from also allowing for internal network feedbacks. These types of network models are called recurrent network models and are used by Jordan (1986) for controlling and learning smooth robot movements, and by Elman (1990) for learning and representing temporal structure in linguistics. In Jordan's network, past values of network output feed back into hidden units; in Elman's network, past values of hidden units feed back into themselves.
European Journal of Control, 2001
In recent years neural networks as multilayer perceptrons and radial basis function networks have been frequently used in a wide range of fields, including control theory, signal processing and nonlinear modelling. A promising new methodology is Support Vector Machines (SVM), which has been originally introduced by Vapnik within the area of statistical learning theory and structural risk minimization. SVM approaches to classification, nonlinear function and density estimation lead to convex optimization problems, typically quadratic programming. However, due to their non-parametric nature, the present SVM methods were basically restricted to static problems. We discuss a method of least squares support vector machines (LS-SVM), which has been extended to recurrent models and use in optimal control problems. We explain how robust nonlinear estimation and sparse approximation can be done by means of this kernel based technique. A short overview of hyperparameter tuning methods is given. SVM methods are able to learn and generalize well in large dimensional input spaces and have outperformed many existing methods on benchmark data sets. Its full potential in a dynamical systems and control context remains to be explored.
this paper presents an auto-regressive network called the Auto-Regressive Multi-Context Recurrent Neural Network (ARMCRN), which forecasts the daily peak load for two large power plant systems. The auto-regressive network is a combination of both recurrent and non-recurrent networks. Weather component variables are the key elements in forecasting because any change in these variables affects the demand of energy load. So the AR-MCRN is used to learn the relationship between past, previous, and future exogenous and endogenous variables. Experimental results show that using the change in weather components and the change that occurred in past load as inputs to the AR-MCRN, rather than the basic weather parameters and past load itself as inputs to the same network, produce higher accuracy of predicted load. Experimental results also show that using exogenous and endogenous variables as inputs is better than using only the exogenous variables as inputs to the network.
Computing Research Repository, 2005
Traditional Support Vector Machines (SVMs) need pre-wired finite time windows to predict and classify time series. They do not have an internal state necessary to deal with sequences involving arbitrary long-term dependencies. Here we introduce a new class of recurrent, truly sequential SVM-like devices with internal adaptive states, trained by a novel method called EVOlution of systems with KErnel-based outputs (Evoke), an instance of the recent Evolino class of methods. Evoke evolves recurrent neural networks to detect and represent temporal dependencies while using quadratic programming/support vector regression to produce precise outputs. Evoke is the first SVM-based mechanism learning to classify a context-sensitive language. It also outperforms recent state-of-the-art gradient-based recurrent neural networks (RNNs) on various time series prediction tasks.
2002
This paper describes an on-line method for building ε-insensitive support vector machines for regression as described in (Vapnik, 1995). The method is an extension of the method developed by(Cauwenberghs & Poggio, 2000) for building incremental support vector machines for classification. Machines obtained byusing this approach are equivalent to the ones obtained byapply- ing exact methods like quadratic programming, but theyare obtained more quicklyand allow the incremental addition of new points, removal of exist- ing points and update of target values for existing data. This development opens the application of SVM regression to areas such as on-line prediction of temporal series or generalization of value functions in reinforcement learning.
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