The Experts below are selected from a list of 135 Experts worldwide ranked by ideXlab platform

Julio H. Braslavsky - One of the best experts on this subject based on the ideXlab platform.

  • Feedback stabilisation of switched systems via iterative Approximate Eigenvector assignment
    arXiv: Systems and Control, 2010
    Co-Authors: Hernan Haimovich, Julio H. Braslavsky
    Abstract:

    This paper presents and implements an iterative feedback design algorithm for stabilisation of discrete-time switched systems under arbitrary switching regimes. The algorithm seeks state feedback gains so that the closed-loop switching system admits a common quadratic Lyapunov function (CQLF) and hence is uniformly globally exponentially stable. Although the feedback design problem considered can be solved directly via linear matrix inequalities (LMIs), direct application of LMIs for feedback design does not provide information on closed-loop system structure. In contrast, the feedback matrices computed by the proposed algorithm assign closed-loop structure approximating that required to satisfy Lie-algebraic conditions that guarantee existence of a CQLF. The main contribution of the paper is to provide, for single-input systems, a numerical implementation of the algorithm based on iterative Approximate common Eigenvector assignment, and to establish cases where such algorithm is guaranteed to succeed. We include pseudocode and a few numerical examples to illustrate advantages and limitations of the proposed technique.

  • CDC - Feedback stabilisation of switched systems via iterative Approximate Eigenvector assignment
    49th IEEE Conference on Decision and Control (CDC), 2010
    Co-Authors: Hernan Haimovich, Julio H. Braslavsky
    Abstract:

    This paper presents and implements an iterative feedback design algorithm for stabilisation of discrete-time switched systems under arbitrary switching regimes. The algorithm seeks state feedback gains so that the closed-loop switching system admits a common quadratic Lyapunov function (CQLF) and hence is uniformly globally exponentially stable. Although the feedback design problem considered can be solved directly via linear matrix inequalities (LMIs), direct application of LMIs for feedback design does not provide information on closed-loop system structure. In contrast, the feedback matrices computed by the proposed algorithm assign closed-loop structure approximating that required to satisfy Lie-algebraic conditions that guarantee existence of a CQLF. The main contribution of the paper is to provide, for single-input systems, a numerical implementation of the algorithm based on iterative Approximate common Eigenvector assignment, and to establish cases where such algorithm is guaranteed to succeed. We include pseudocode and a few numerical examples to illustrate advantages and limitations of the proposed technique.

Markowitch Olivier - One of the best experts on this subject based on the ideXlab platform.

  • Multi-party (leveled) homomorphic encryption on identity-based and attribute-based settings
    'Springer Science and Business Media LLC', 2018
    Co-Authors: Kuchta Veronika, Sharma Gaurav, Sahu, Rajeev Anand, Markowitch Olivier
    Abstract:

    We present constructions of CPA-secure (leveled) homomorphic encryption from learning with errors (LWE) problem. We use the construction introduced by Gentry, Sahai and Waters 'GSW' (CRYPTO'13) as building blocks of our schemes. We apply their Approximate Eigenvector method to our scheme. In contrast to the GSW scheme we provide extensions of the (leveled) homomorphic identity-based encryption (IBE) and (leveled) homomorphic attribute-based encryption (ABE) on the multi-identity and multi-attribute settings respectively. We realize the (leveled) homomorphic property for the multi-party setting by applying tensor product and natural logarithm. Tensor product and natural logarithm allow to evaluate different ciphertexts computed under different public keys. Similar to the GSW scheme, our constructions do not need any evaluation key, which enables evaluation even without the knowledge of user's public key

  • Multi-Party (Leveled) Homomorphic Encryption on Identity-Based and Attribute-Based Settings: Information security and cryptography - ICISC
    'Springer Science and Business Media LLC', 2017
    Co-Authors: Kuchta Veronika, Sharma Gaurav, Sahu, Rajeev Anand, Markowitch Olivier
    Abstract:

    We present constructions of CPA-secure (leveled) homomorphic encryption from learning with errors (LWE) problem. We use the construction introduced by Gentry, Sahai and Waters ‘GSW’ (CRYPTO’13) as building blocks of our schemes. We apply their Approximate Eigenvector method to our scheme. In contrast to the GSW scheme we provide extensions of the (leveled) homomorphic identity-based encryption (IBE) and (leveled) homomorphic attribute-based encryption (ABE) on the multi-identity and multi-attribute settings respectively. We realize the (leveled) homomorphic property for the multi-party setting by applying tensor product and natural logarithm. Tensor product and natural logarithm allow to evaluate different ciphertexts computed under different public keys. Similar to the GSW scheme, our constructions do not need any evaluation key, which enables evaluation even without the knowledge of user’s public key.SCOPUS: cp.kinfo:eu-repo/semantics/publishe

Claudio Padra - One of the best experts on this subject based on the ideXlab platform.

  • A POSTERIORI ERROR ESTIMATORS FOR MIXED APPROXIMATIONS OF EIGENVALUE PROBLEMS
    Mathematical Models and Methods in Applied Sciences, 1999
    Co-Authors: Ricardo G. Durán, Lucia Gastaldi, Claudio Padra
    Abstract:

    In this paper we introduce and analyze an a posteriori error estimator for the approximation of the eigenvalues and Eigenvectors of a second-order elliptic problem obtained by the mixed finite element method of Raviart–Thomas of the lowest order. We define an error estimator of the residual type which can be computed locally from the Approximate Eigenvector and prove that the estimator is equivalent to the norm of the error in the approximation of the Eigenvector up to higher order terms. The constants involved in this equivalence depend on the corresponding eigenvalue but are independent of the mesh size, provided the meshes satisfy the usual minimum angle condition. Moreover, the square root of the error in the approximation of the eigenvalue is also bounded by a constant times the estimator.

Hernan Haimovich - One of the best experts on this subject based on the ideXlab platform.

  • Feedback stabilisation of switched systems via iterative Approximate Eigenvector assignment
    arXiv: Systems and Control, 2010
    Co-Authors: Hernan Haimovich, Julio H. Braslavsky
    Abstract:

    This paper presents and implements an iterative feedback design algorithm for stabilisation of discrete-time switched systems under arbitrary switching regimes. The algorithm seeks state feedback gains so that the closed-loop switching system admits a common quadratic Lyapunov function (CQLF) and hence is uniformly globally exponentially stable. Although the feedback design problem considered can be solved directly via linear matrix inequalities (LMIs), direct application of LMIs for feedback design does not provide information on closed-loop system structure. In contrast, the feedback matrices computed by the proposed algorithm assign closed-loop structure approximating that required to satisfy Lie-algebraic conditions that guarantee existence of a CQLF. The main contribution of the paper is to provide, for single-input systems, a numerical implementation of the algorithm based on iterative Approximate common Eigenvector assignment, and to establish cases where such algorithm is guaranteed to succeed. We include pseudocode and a few numerical examples to illustrate advantages and limitations of the proposed technique.

  • CDC - Feedback stabilisation of switched systems via iterative Approximate Eigenvector assignment
    49th IEEE Conference on Decision and Control (CDC), 2010
    Co-Authors: Hernan Haimovich, Julio H. Braslavsky
    Abstract:

    This paper presents and implements an iterative feedback design algorithm for stabilisation of discrete-time switched systems under arbitrary switching regimes. The algorithm seeks state feedback gains so that the closed-loop switching system admits a common quadratic Lyapunov function (CQLF) and hence is uniformly globally exponentially stable. Although the feedback design problem considered can be solved directly via linear matrix inequalities (LMIs), direct application of LMIs for feedback design does not provide information on closed-loop system structure. In contrast, the feedback matrices computed by the proposed algorithm assign closed-loop structure approximating that required to satisfy Lie-algebraic conditions that guarantee existence of a CQLF. The main contribution of the paper is to provide, for single-input systems, a numerical implementation of the algorithm based on iterative Approximate common Eigenvector assignment, and to establish cases where such algorithm is guaranteed to succeed. We include pseudocode and a few numerical examples to illustrate advantages and limitations of the proposed technique.

Kuchta Veronika - One of the best experts on this subject based on the ideXlab platform.

  • Multi-party (leveled) homomorphic encryption on identity-based and attribute-based settings
    'Springer Science and Business Media LLC', 2018
    Co-Authors: Kuchta Veronika, Sharma Gaurav, Sahu, Rajeev Anand, Markowitch Olivier
    Abstract:

    We present constructions of CPA-secure (leveled) homomorphic encryption from learning with errors (LWE) problem. We use the construction introduced by Gentry, Sahai and Waters 'GSW' (CRYPTO'13) as building blocks of our schemes. We apply their Approximate Eigenvector method to our scheme. In contrast to the GSW scheme we provide extensions of the (leveled) homomorphic identity-based encryption (IBE) and (leveled) homomorphic attribute-based encryption (ABE) on the multi-identity and multi-attribute settings respectively. We realize the (leveled) homomorphic property for the multi-party setting by applying tensor product and natural logarithm. Tensor product and natural logarithm allow to evaluate different ciphertexts computed under different public keys. Similar to the GSW scheme, our constructions do not need any evaluation key, which enables evaluation even without the knowledge of user's public key

  • Multi-Party (Leveled) Homomorphic Encryption on Identity-Based and Attribute-Based Settings: Information security and cryptography - ICISC
    'Springer Science and Business Media LLC', 2017
    Co-Authors: Kuchta Veronika, Sharma Gaurav, Sahu, Rajeev Anand, Markowitch Olivier
    Abstract:

    We present constructions of CPA-secure (leveled) homomorphic encryption from learning with errors (LWE) problem. We use the construction introduced by Gentry, Sahai and Waters ‘GSW’ (CRYPTO’13) as building blocks of our schemes. We apply their Approximate Eigenvector method to our scheme. In contrast to the GSW scheme we provide extensions of the (leveled) homomorphic identity-based encryption (IBE) and (leveled) homomorphic attribute-based encryption (ABE) on the multi-identity and multi-attribute settings respectively. We realize the (leveled) homomorphic property for the multi-party setting by applying tensor product and natural logarithm. Tensor product and natural logarithm allow to evaluate different ciphertexts computed under different public keys. Similar to the GSW scheme, our constructions do not need any evaluation key, which enables evaluation even without the knowledge of user’s public key.SCOPUS: cp.kinfo:eu-repo/semantics/publishe