We study optimization problems subject to possible fatal failures. The probability of failure should not exceed a given confidence level. The distribution of the failure event is assumed unknown, but it can be generat...
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We study optimization problems subject to possible fatal failures. The probability of failure should not exceed a given confidence level. The distribution of the failure event is assumed unknown, but it can be generated via simulation or observation of historical data. gradient-based simulation-optimization methods pose the difficulty of the estimation of the gradient of the probability constraint under no knowledge of the distribution. In this work we provide two single-path estimators with bias: a convolution method and a finite difference, and we provide a full analysis of convergence of the Arrow-Hurwicz algorithm, which we use as our solver for optimization. Convergence results are used to tune the parameters of the numerical algorithms in order to achieve best convergence rates, and numerical results are included via an example of application in finance. (C) 2011 Elsevier B.V. All rights reserved.
This paper addresses the combined estimation issues of the parameters and states for fractional-order Hammerstein state space systems with colored noises. An extended state estimator is derived by using the parameter ...
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This paper addresses the combined estimation issues of the parameters and states for fractional-order Hammerstein state space systems with colored noises. An extended state estimator is derived by using the parameter estimates to replace the unknown system parameters in Kalman filter. The hierarchical identification principle is introduced to solve the unknown parameters of measurement noises. By introducing the forgetting factor, an extended Kalman filtering-based hierarchical forgetting factor stochastic gradient algorithm is presented to estimate the unknown states, parameters and fractional-order. A numerical example is respectively presented to demonstrate the feasibility of the proposed identification algorithm. It can be seen that the estimation errors are relatively small, which reflects the proposed algorithms have good identification effect.
This paper analyzes the training process of generative adversarial networks (GANs) via stochastic differential equations (SDEs). It first establishes SDE approximations for the training of GANs under stochastic gradie...
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This paper analyzes the training process of generative adversarial networks (GANs) via stochastic differential equations (SDEs). It first establishes SDE approximations for the training of GANs under stochastic gradient algorithms, with precise error bound analysis. It then describes the long-run behavior of GAN training via the invariant measures of its SDE approximations under proper conditions. This work builds a theoretical foundation for GAN training and provides analytical tools to study its evolution and stability.
The autoregressive moving average exogenous (ARMAX) model is commonly adopted for describing linear stochastic systems driven by colored noise. The model is a finite mixture with the ARMA component and external inpu...
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The autoregressive moving average exogenous (ARMAX) model is commonly adopted for describing linear stochastic systems driven by colored noise. The model is a finite mixture with the ARMA component and external inputs. In this paper we focus on a parameter estimate of the ARMAX model. Classical modeling methods are usually based on the assumption that the driven noise in the moving average (MA) part has bounded variances, while in the model considered here the variances of noise may increase by a power of log n. The plant parameters are identified by the recursive stochastic gradient algorithm. The diminishing excitation technique and some results of martingale difference theory are adopted in order to prove the convergence of the identification. Finally, some simulations are given to show the reliability of the theoretical results.
In this paper we study and solve two different variants of static knapsack problems with random weights: The stochastic knapsack problem with simple recourse as well as the stochastic knapsack problem with probabilist...
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In this paper we study and solve two different variants of static knapsack problems with random weights: The stochastic knapsack problem with simple recourse as well as the stochastic knapsack problem with probabilistic constraint. Special interest is given to the corresponding continuous problems and three different problem solving methods are presented. The resolution of the continuous problems allows to provide upper bounds in a branch-and-bound framework in order to solve the original problems. Numerical results on a dataset from the literature as well as a set of randomly generated instances are given.
This article proposes the methods of parameter estimation and state estimation to calculate state space systems with delay. Associating the properties of linear conversion and shift operators, the state space model ca...
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This article proposes the methods of parameter estimation and state estimation to calculate state space systems with delay. Associating the properties of linear conversion and shift operators, the state space model can be equal to the standard state space model, which can then be converted into the recognition model. The proposed stochasticgradient method is brought to calculate the system and converge to the recursive least squares estimates for state space models. Finally, one example is proposed to certify the theorems of this paper.
In this paper, we apply machine learning to distributed private data owned by multiple data owners, entities with access to non-overlapping training datasets. We use noisy, differentially-private gradients to minimize...
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ISBN:
(数字)9781728134970
ISBN:
(纸本)9781728134970
In this paper, we apply machine learning to distributed private data owned by multiple data owners, entities with access to non-overlapping training datasets. We use noisy, differentially-private gradients to minimize the fitness cost of the machine learning model using stochasticgradient descent. We quantify the quality of the trained model, using the fitness cost, as a function of privacy budget and size of the distributed datasets to capture the trade-off between privacy and utility in machine learning. This way, we can predict the outcome of collaboration among privacy-aware data owners prior to executing potentially computationally-expensive machine learning algorithms. Particularly, we show that the difference between the fitness of the trained machine learning model using differentially-private gradient queries and the fitness of the trained machine model in the absence of any privacy concerns is inversely proportional to the size of the training datasets squared and the privacy budget squared. We successfully validate the performance prediction with the actual performance of the proposed privacy-aware learning algorithms, applied to: financial datasets for determining interest rates of loans using regression;and detecting credit card frauds using support vector machines.
In this paper. we propose a novel estimation algorithm for a dual-rate system with preload nonlinearity. The input-output data are measured two different sampling rates. A switching function and a polynomial transform...
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ISBN:
(数字)9783642273292
ISBN:
(纸本)9783642273285;9783642273292
In this paper. we propose a novel estimation algorithm for a dual-rate system with preload nonlinearity. The input-output data are measured two different sampling rates. A switching function and a polynomial transformation technique are employed to derive a mathematical model for such a dual-rate and nonlinear system. Furthermore, two modified stochastic gradient algorithms are given to improve the convergence rate. Finally a simulation example is provided to verify the effectiveness of the proposed method.
This paper considers the identification problem of linear regression model with quantized observations. We propose a modified stochastic gradient algorithm to estimate unknown parameters using the quanized observation...
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ISBN:
(纸本)9798350366907;9789887581581
This paper considers the identification problem of linear regression model with quantized observations. We propose a modified stochastic gradient algorithm to estimate unknown parameters using the quanized observations. Under the "weakest" excitation condition, we show that the proposed algorithm converges to the true parameters without requiring the commonly used i.i.d. conditions. Based on this, the convergence rate is further considered. Finally, simulation results are given to demonstrate the effectiveness of the proposed algorithm.
It is well known, combination scheme is suitable for improving the performance of adaptive algorithms. In this paper, we propose a subband combination scheme for sparse impulse response system. The combination is carr...
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ISBN:
(纸本)9781612848570
It is well known, combination scheme is suitable for improving the performance of adaptive algorithms. In this paper, we propose a subband combination scheme for sparse impulse response system. The combination is carried out in subband domain. In this convex combination, SIPNLMS and SNLMS are derived for fast convergence and small steady state error respectively. And mixing parameters are described by minimum mean square error and stochastic gradient algorithm. In adaptive system identification scenario, the advantages of this proposed method are illustrated.
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