The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform
Zidong Wang - One of the best experts on this subject based on the ideXlab platform.
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Mean-Square $H_\infty $ Consensus Control for a Class of Nonlinear Time-Varying Stochastic Multiagent Systems: The Finite-Horizon Case
IEEE Transactions on Systems Man and Cybernetics: Systems, 2017Co-Authors: Zidong WangAbstract:This paper deals with the consensus control problem for a class of nonlinear discrete time-varying stochastic multiagent systems (MASs) over a finite horizon via static output feedback. The measurement output available for the controller is not only from the individual agent itself but also from its neighboring ones according to the given topology. The nonlinearities described by statistical means can encompass several classes of well-studied nonlinearities in the literature. A new index of mean-square consensus performance, which quantifies the deviation level from the state of individual agent to the average value of all agents' states, is proposed to reflect the transient consensus behavior of the MAS. The purpose of the addressed problem is to design a time-varying output feedback controller such that: 1) the H∞ consensus performance defined over a given finite horizon is guaranteed with respect to the additive noises and 2) at each time step, the mean-square consensus performance satisfies the prespecified Upper Bound Constraint. By using a set of recursive matrix inequalities, sufficient conditions are derived for the existence of the desired control scheme for achieving both H∞ and mean-square consensus performance requirements. Finally, a simulation example is utilized to illustrate the usefulness of the proposed control protocol.
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robust h sub spl infin filter design with variance Constraints and parabolic pole assignment
IEEE Signal Processing Letters, 2006Co-Authors: Zidong Wang, Jianan FangAbstract:In this letter, we consider a multiobjective filtering problem for uncertain linear continuous time-invariant systems subject to error variance Constraints. A linear filter is used to estimate a linear combination of the system states. The problem addressed is the design of a filter such that, for all admissible parameter uncertainties, the following three objectives are simultaneously achieved: 1) the filtering process is P-stable, i.e., the poles of the filtering matrix are located inside a parabolic region; 2) the steady-state variance of the estimation error of each state is not more than the individual prespecified value; and 3) the transfer function from exogenous noise inputs to error state outputs meets the prespecified H/sub /spl infin// norm Upper-Bound Constraint. An effective algebraic matrix inequality approach is developed to derive both the existence conditions and the explicit expression of the desired filters. An illustrative example is used to demonstrate the usefulness of the proposed design approach.
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Robust filtering for uncertain linear systems with delayed states and outputs
IEEE Transactions on Circuits and Systems I: Fundamental Theory and Applications, 2002Co-Authors: Zidong Wang, Fuwen YangAbstract:Deals with the robust filtering problem for uncertain linear systems with delayed states and outputs. Both time-invariant and time-varying cases are considered. For the time-invariant case, an algebraic Riccati matrix inequality approach is proposed to design a robust H/sub /spl infin// filter such that the filtering process remains asymptotically stable for all admissible uncertainties, and the transfer function from the disturbance inputs to error state outputs satisfies the prespecified H/sub /spl infin// norm Upper Bound Constraint. We establish the conditions under which the desired robust H/sub /spl infin// filters exist, and derive the explicit expression of these filters. For the time-varying case, we develop a differential Riccati inequality method to design the robust filters. A numerical example is provided to demonstrate the validity of the proposed design approach.
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Robust H/sub 2//H/sub /spl infin// filtering for linear systems with error variance Constraints
IEEE Transactions on Signal Processing, 2000Co-Authors: Zidong Wang, Biao HuangAbstract:In this correspondence, we consider the robust H/sub 2//H/sub /spl infin// filtering problem for linear perturbed systems with steady-state error variance Constraints. The purpose of this multiobjective problem is to design a linear filter that does not depend on the parameter perturbations such that the following three performance requirements are simultaneously satisfied. (1) The filtering process is asymptotically stable. (2) The steady-state variance of the estimation error of each state is not more than the individual prespecified value. (3) The transfer function from exogenous noise inputs to error state outputs meets the prespecified H/sub /spl infin// norm Upper Bound Constraint. We show that in both continuous and discrete-time cases, the addressed filtering problem can effectively be solved in terms of the solutions of a couple of algebraic Riccati-like equations/inequalities. We present both the existence conditions and the explicit expression of desired robust filters. An illustrative numerical example is provided to demonstrate the flexibility of the proposed design approach.
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technical communique robust h observer design of linear state delayed systems with parametric uncertainty the discrete time case
Automatica, 1999Co-Authors: Zidong Wang, Biao Huang, H. UnbehauenAbstract:In this note we consider the problem of H"~ observer design for a class of uncertain linear discrete-time systems with delayed state and parameter uncertainties. The goal of this problem is to design a linear state observer such that, for the positive integer state time-delay and all admissible norm-Bounded parameter uncertainties, the observation process remains robustly stable and the transfer function from exogenous disturbances to error state outputs meets the prespecified H"~-norm Upper-Bound Constraint. The observer structure does not depend on the parameter uncertainties. A simple, effective algebraic methodology is developed to derive the conditions for the existence of the desired robust H"~ observers, and the analytical expression of these observers is then characterized in terms of the matrix Riccati-like equations/inequalities. We provide a numerical example to demonstrate the validity and the applicability of the proposed approach.
H. Unbehauen - One of the best experts on this subject based on the ideXlab platform.
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technical communique robust h observer design of linear state delayed systems with parametric uncertainty the discrete time case
Automatica, 1999Co-Authors: Zidong Wang, Biao Huang, H. UnbehauenAbstract:In this note we consider the problem of H"~ observer design for a class of uncertain linear discrete-time systems with delayed state and parameter uncertainties. The goal of this problem is to design a linear state observer such that, for the positive integer state time-delay and all admissible norm-Bounded parameter uncertainties, the observation process remains robustly stable and the transfer function from exogenous disturbances to error state outputs meets the prespecified H"~-norm Upper-Bound Constraint. The observer structure does not depend on the parameter uncertainties. A simple, effective algebraic methodology is developed to derive the conditions for the existence of the desired robust H"~ observers, and the analytical expression of these observers is then characterized in terms of the matrix Riccati-like equations/inequalities. We provide a numerical example to demonstrate the validity and the applicability of the proposed approach.
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Robust H/sub 2//H/sub /spl infin//-state estimation for systems with error variance Constraints: the continuous-time case
IEEE Transactions on Automatic Control, 1999Co-Authors: Zidong Wang, H. UnbehauenAbstract:The paper is concerned with the state estimator design problem for perturbed linear continuous-time systems with H/sub /spl infin// norm and variance Constraints. The perturbation is assumed to be time-invariant and norm-Bounded and enters into both the state and measurement matrices. The problem we address is to design a linear state estimator such that, for all admissible measurable perturbations, the variance of the estimation error of each state is not more than the individual prespecified value, and the transfer function from disturbances to error state outputs satisfies the prespecified H/sub /spl infin// norm Upper Bound Constraint, simultaneously. Existence conditions of the desired estimators are derived in terms of Riccati-type matrix inequalities, and the analytical expression of these estimators is also presented. A numerical example is provided to show the directness and effectiveness of the proposed design approach.
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A novel approach to H/sub 2//H/sub /spl infin// robotic control with state estimation feedback
Proceedings of the 1998 IEEE International Conference on Control Applications (Cat. No.98CH36104), 1998Co-Authors: Zidong Wang, H. Zeng, H. UnbehauenAbstract:We consider the problem of designing H/sub /spl infin// controllers for linear continuous- and discrete-time systems with Upper Bound Constraints on the steady-state variances. The feedback is based on the state estimation. The goal of this problem is to design the state estimation feedback controller such that: 1) the steady-state variance of each state is not more than the individual prespecified Upper Bound; and 2) the H/sub /spl infin// norm of the transfer function from disturbance inputs to state estimate output meets the prespecified Upper Bound Constraint, simultaneously. An algebraic matrix equation approach is developed to solve the problem addressed. Both the existence conditions and the explicit expression of desired controllers are derived, and an illustrative simulation example is used to demonstrate the applicability of the proposed design procedure in a manipulator control problem.
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Robust H/sub 2//H/sub /spl infin//-state estimation for discrete-time systems with error variance Constraints
IEEE Transactions on Automatic Control, 1997Co-Authors: Zidong Wang, H. UnbehauenAbstract:This paper studies the problem of an H/sub /spl infin//-norm and variance-constrained state estimator design for uncertain linear discrete-time systems. The system under consideration is subjected to time-invariant norm-Bounded parameter uncertainties in both the state and measurement matrices. The problem addressed is the design of a gain-scheduled linear state estimator such that, for all admissible measurable uncertainties, the variance of the estimation error of each state is not more than the individual prespecified value, and the transfer function from disturbances to error state outputs satisfies the prespecified H/sub /spl infin//-norm Upper Bound Constraint, simultaneously. The conditions for the existence of desired estimators are obtained in terms of matrix inequalities, and the explicit expression of these estimators is also derived. A numerical example is provided to demonstrate various aspects of theoretical results.
Biao Huang - One of the best experts on this subject based on the ideXlab platform.
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monitoring control performance via structured closed loop response subject to output variance covariance Upper Bound
Journal of Process Control, 2006Co-Authors: Fangwei Xu, Biao HuangAbstract:Abstract Owing to the process time delays, the closed-loop response can be divided into feedback control invariant part and feedback controller dependent part. If the latter part is replaced by a user specified response trajectory, we refer to the resultant closed-loop response as structured closed-loop response. The user specified structured closed-loop response has been used as an achievable control against which one can assess performance of control loops. In the control performance monitoring literature, the user specified response is often given as a first-order transfer function with some specified performance requirement, such as time constant. In this paper, we solve this problem from a systematic approach, i.e., in viewpoint of a variance/covariance Upper Bound on the outputs. With available closed-loop routine operating output data and process time delay/interactor matrix, the desired structured closed-loop response can be obtained directly via estimated closed-loop time series model. A significant feature is that the output variance/covariance Upper Bound Constraint can be explicitly specified according to the product specifications and is always satisfied when the problem is feasible. This desired structured closed-loop response can thus be served as a benchmark against which the existing controller performance can be compared. We also show that two approaches, linearizing change of variables and Frank and Wolfe algorithm, are suitable for solving this problem, which result in a full order and a reduced order structured closed-loop response, respectively. Both approaches are illustrated by two case studies.
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Robust H/sub 2//H/sub /spl infin// filtering for linear systems with error variance Constraints
IEEE Transactions on Signal Processing, 2000Co-Authors: Zidong Wang, Biao HuangAbstract:In this correspondence, we consider the robust H/sub 2//H/sub /spl infin// filtering problem for linear perturbed systems with steady-state error variance Constraints. The purpose of this multiobjective problem is to design a linear filter that does not depend on the parameter perturbations such that the following three performance requirements are simultaneously satisfied. (1) The filtering process is asymptotically stable. (2) The steady-state variance of the estimation error of each state is not more than the individual prespecified value. (3) The transfer function from exogenous noise inputs to error state outputs meets the prespecified H/sub /spl infin// norm Upper Bound Constraint. We show that in both continuous and discrete-time cases, the addressed filtering problem can effectively be solved in terms of the solutions of a couple of algebraic Riccati-like equations/inequalities. We present both the existence conditions and the explicit expression of desired robust filters. An illustrative numerical example is provided to demonstrate the flexibility of the proposed design approach.
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technical communique robust h observer design of linear state delayed systems with parametric uncertainty the discrete time case
Automatica, 1999Co-Authors: Zidong Wang, Biao Huang, H. UnbehauenAbstract:In this note we consider the problem of H"~ observer design for a class of uncertain linear discrete-time systems with delayed state and parameter uncertainties. The goal of this problem is to design a linear state observer such that, for the positive integer state time-delay and all admissible norm-Bounded parameter uncertainties, the observation process remains robustly stable and the transfer function from exogenous disturbances to error state outputs meets the prespecified H"~-norm Upper-Bound Constraint. The observer structure does not depend on the parameter uncertainties. A simple, effective algebraic methodology is developed to derive the conditions for the existence of the desired robust H"~ observers, and the analytical expression of these observers is then characterized in terms of the matrix Riccati-like equations/inequalities. We provide a numerical example to demonstrate the validity and the applicability of the proposed approach.
Jinjun Chen - One of the best experts on this subject based on the ideXlab platform.
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A privacy leakage Upper Bound Constraint-based approach for cost-effective privacy preserving of intermediate data sets in cloud
IEEE Transactions on Parallel and Distributed Systems, 2013Co-Authors: Xuyun Zhang, Suraj Pandey, Surya Nepal, Chang Liu, Jinjun ChenAbstract:Cloud computing provides massive computation power and storage capacity which enable users to deploy computation and data-intensive applications without infrastructure investment. Along the processing of such applications, a large volume of intermediate data sets will be generated, and often stored to save the cost of recomputing them. However, preserving the privacy of intermediate data sets becomes a challenging problem because adversaries may recover privacy-sensitive information by analyzing multiple intermediate data sets. Encrypting ALL data sets in cloud is widely adopted in existing approaches to address this challenge. But we argue that encrypting all intermediate data sets are neither efficient nor cost-effective because it is very time consuming and costly for data-intensive applications to en/decrypt data sets frequently while performing any operation on them. In this paper, we propose a novel Upper Bound privacy leakage Constraint-based approach to identify which intermediate data sets need to be encrypted and which do not, so that privacy-preserving cost can be saved while the privacy requirements of data holders can still be satisfied. Evaluation results demonstrate that the privacy-preserving cost of intermediate data sets can be significantly reduced with our approach over existing ones where all data sets are encrypted.
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SKG - Dynamic Setting, Verification and Adjustment of Upper Bound Constraints in Grid Workflow Systems
2006 Semantics Knowledge and Grid Second International Conference on, 2006Co-Authors: Jinjun Chen, Yun YangAbstract:Upper Bound Constraints are often set when complex scientific or business processes are modelled as grid workflow specifications. However, many existing processes such as climate modelling or international stock market analysis often have only one end-to-end Upper Bound Constraint. This is not sufficient to control overall temporal correctness as we may not find temporal violations until the last activity. Then, it is too late to take any handling actions. Consequently, the execution results may not be useful and overall cost-effectiveness would be impacted. Therefore, in this paper, we systematically investigate how to set, verify and adjust sub-Upper Bound Constraints within the timeframe of one end-to-end Upper Bound Constraint so that we can control grid workflow execution locally. We develop corresponding setting, verification and adjustment methods and algorithms. The quantitative evaluation demonstrates that with sub-Upper Bound Constraints, we can achieve better cost-effectiveness than only based on one end-to-end Upper Bound Constraint.
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Dynamic Setting, Verification and Adjustment of Upper Bound Constraints in Grid Workflow Systems
2006 Semantics Knowledge and Grid Second International Conference on, 2006Co-Authors: Jinjun Chen, Yun YangAbstract:Upper Bound Constraints are often set when complex scientific or business processes are modelled as grid workflow specifications. However, many existing processes such as climate modelling or international stock market analysis often have only one end-to-end Upper Bound Constraint. This is not sufficient to control overall temporal correctness as we may not find temporal violations until the last activity. Then, it is too late to take any handling actions. Consequently, the execution results may not be useful and overall cost-effectiveness would be impacted. Therefore, in this paper, we systematically investigate how to set, verify and adjust sub-Upper Bound Constraints within the timeframe of one end-to-end Upper Bound Constraint so that we can control grid workflow execution locally. We develop corresponding setting, verification and adjustment methods and algorithms. The quantitative evaluation demonstrates that with sub-Upper Bound Constraints, we can achieve better cost-effectiveness than only based on one end-to-end Upper Bound Constraint.
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e-Science - Multiple temporal consistency states for dynamical verification of Upper Bound Constraints in grid workflow systems
First International Conference on e-Science and Grid Computing (e-Science'05), 2005Co-Authors: Jinjun Chen, Yun YangAbstract:Conventional Upper Bound Constraint verification in grid workflow systems is based on the key assumption that an Upper Bound Constraint only has two states: consistency and inconsistency. However, due to complexity of grid workflows and dynamic availability of participating grid services, this assumption is too restrictive as there may be some intermediate states. Therefore, in this paper, we introduce four states for an Upper Bound Constraint. Namely, we treat conventional consistency as strong consistency and divide conventional inconsistency into weak consistency, weak inconsistency and strong inconsistency. Correspondingly, we develop their verification methods. For weak consistency, we present some algorithms on how to adjust it to strong consistency without triggering exception handling as in conventional work. For weak inconsistency, we analyse why it can rely on less costly exception handling than conventional work. The final evaluation demonstrates that our four-state approach can achieve better cost-effectiveness than the conventional two-state approach
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Multiple temporal consistency states for dynamical verification of Upper Bound Constraints in grid workflow systems
First International Conference on e-Science and Grid Computing (e-Science'05), 2005Co-Authors: Jinjun Chen, Yun YangAbstract:Conventional Upper Bound Constraint verification in grid workflow systems is based on the key assumption that an Upper Bound Constraint only has two states: consistency and inconsistency. However, due to complexity of grid workflows and dynamic availability of participating grid services, this assumption is too restrictive as there may be some intermediate states. Therefore, in this paper, we introduce four states for an Upper Bound Constraint. Namely, we treat conventional consistency as strong consistency and divide conventional inconsistency into weak consistency, weak inconsistency and strong inconsistency. Correspondingly, we develop their verification methods. For weak consistency, we present some algorithms on how to adjust it to strong consistency without triggering exception handling as in conventional work. For weak inconsistency, we analyse why it can rely on less costly exception handling than conventional work. The final evaluation demonstrates that our four-state approach can achieve better cost-effectiveness than the conventional two-state approach
Yun Yang - One of the best experts on this subject based on the ideXlab platform.
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SKG - Dynamic Setting, Verification and Adjustment of Upper Bound Constraints in Grid Workflow Systems
2006 Semantics Knowledge and Grid Second International Conference on, 2006Co-Authors: Jinjun Chen, Yun YangAbstract:Upper Bound Constraints are often set when complex scientific or business processes are modelled as grid workflow specifications. However, many existing processes such as climate modelling or international stock market analysis often have only one end-to-end Upper Bound Constraint. This is not sufficient to control overall temporal correctness as we may not find temporal violations until the last activity. Then, it is too late to take any handling actions. Consequently, the execution results may not be useful and overall cost-effectiveness would be impacted. Therefore, in this paper, we systematically investigate how to set, verify and adjust sub-Upper Bound Constraints within the timeframe of one end-to-end Upper Bound Constraint so that we can control grid workflow execution locally. We develop corresponding setting, verification and adjustment methods and algorithms. The quantitative evaluation demonstrates that with sub-Upper Bound Constraints, we can achieve better cost-effectiveness than only based on one end-to-end Upper Bound Constraint.
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Dynamic Setting, Verification and Adjustment of Upper Bound Constraints in Grid Workflow Systems
2006 Semantics Knowledge and Grid Second International Conference on, 2006Co-Authors: Jinjun Chen, Yun YangAbstract:Upper Bound Constraints are often set when complex scientific or business processes are modelled as grid workflow specifications. However, many existing processes such as climate modelling or international stock market analysis often have only one end-to-end Upper Bound Constraint. This is not sufficient to control overall temporal correctness as we may not find temporal violations until the last activity. Then, it is too late to take any handling actions. Consequently, the execution results may not be useful and overall cost-effectiveness would be impacted. Therefore, in this paper, we systematically investigate how to set, verify and adjust sub-Upper Bound Constraints within the timeframe of one end-to-end Upper Bound Constraint so that we can control grid workflow execution locally. We develop corresponding setting, verification and adjustment methods and algorithms. The quantitative evaluation demonstrates that with sub-Upper Bound Constraints, we can achieve better cost-effectiveness than only based on one end-to-end Upper Bound Constraint.
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e-Science - Multiple temporal consistency states for dynamical verification of Upper Bound Constraints in grid workflow systems
First International Conference on e-Science and Grid Computing (e-Science'05), 2005Co-Authors: Jinjun Chen, Yun YangAbstract:Conventional Upper Bound Constraint verification in grid workflow systems is based on the key assumption that an Upper Bound Constraint only has two states: consistency and inconsistency. However, due to complexity of grid workflows and dynamic availability of participating grid services, this assumption is too restrictive as there may be some intermediate states. Therefore, in this paper, we introduce four states for an Upper Bound Constraint. Namely, we treat conventional consistency as strong consistency and divide conventional inconsistency into weak consistency, weak inconsistency and strong inconsistency. Correspondingly, we develop their verification methods. For weak consistency, we present some algorithms on how to adjust it to strong consistency without triggering exception handling as in conventional work. For weak inconsistency, we analyse why it can rely on less costly exception handling than conventional work. The final evaluation demonstrates that our four-state approach can achieve better cost-effectiveness than the conventional two-state approach
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Multiple temporal consistency states for dynamical verification of Upper Bound Constraints in grid workflow systems
First International Conference on e-Science and Grid Computing (e-Science'05), 2005Co-Authors: Jinjun Chen, Yun YangAbstract:Conventional Upper Bound Constraint verification in grid workflow systems is based on the key assumption that an Upper Bound Constraint only has two states: consistency and inconsistency. However, due to complexity of grid workflows and dynamic availability of participating grid services, this assumption is too restrictive as there may be some intermediate states. Therefore, in this paper, we introduce four states for an Upper Bound Constraint. Namely, we treat conventional consistency as strong consistency and divide conventional inconsistency into weak consistency, weak inconsistency and strong inconsistency. Correspondingly, we develop their verification methods. For weak consistency, we present some algorithms on how to adjust it to strong consistency without triggering exception handling as in conventional work. For weak inconsistency, we analyse why it can rely on less costly exception handling than conventional work. The final evaluation demonstrates that our four-state approach can achieve better cost-effectiveness than the conventional two-state approach
