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Concept

Nilpotent matrix

Related publications (18)

Koopman-based Data-driven Robust Control of Nonlinear Systems Using Integral Quadratic Constraints

Alireza Karimi, Mert Eyuboglu

This paper introduces a novel method for data-driven robust control of nonlinear systems based on the Koopman operator, utilizing Integral Quadratic Constraints (IQCs). The Koopman operator theory facilitates the linear representation of nonlinear system d ...

2024

Lie groups as permutation groups: Ulam's problem in the nilpotent case

Nicolas Monod

Ulam asked whether every connected Lie group can be represented on a countable structure. This is known in the linear case. We establish it for the first family of non-linear groups, namely in the nilpotent case. Further context is discussed to illustrate ...

WALTER DE GRUYTER GMBH2022

A convex set of robust D—stabilizing controllers using Cauchy's argument principle

Alireza Karimi, Philippe Louis Schuchert

A new approach is presented to obtain a convex set of robust D—stabilizing fixed structure controllers, relying on Cauchy's argument principle. A convex set of D—stabilizing controllers around an initial D—stabilizing controller for a multi-model set is re ...

Elsevier2022

Discrete-time regional pole-placement using convex approximations: Theory and application to a boost converter

Emilio Maddalena

The problem of allocating the closed-loop poles of linear systems in specific regions of the complex plane defined by discrete time-domain requirements is addressed. The resulting non-convex set is inner-approximated by a convex region described with linea ...

2019

Decentralized and distributed robust control invariance for constrained linear systems

Giancarlo Ferrari Trecate

In this paper we propose an efficient procedure to compute time-varying Robust Control Invariant (RCI) sets for large-scale systems arising from the interconnection of M Linear Time-Invariant (LTI) constrained subsystems. In particular, the associated stat ...

IEEE2017

Fixed-order Linear Parameter Varying Controller Design for a 2DOF Gyroscope

Alireza Karimi, Zlatko Emedi

This paper presents an approach for fixed-order Linear Parameter Varying (LPV) controller design with application to a 2 Degree-of-Freedom (2DOF) gyroscope experimental setup. Inner convex approximation of the non-convex set of all stabilizing fixed-order ...

2015

Fixed-structure LPV Discrete-time Controller Design with Induced l2-Norm and H2 Performance

Alireza Karimi, Zlatko Emedi

A new method for the design of fixed-structure dynamic output-feedback Linear Parameter Varying (LPV) controllers for discrete-time LPV systems with bounded scheduling parameter variations is presented. Sufficient conditions for the stability, $\mathscr{H} ...

2015

Fixed-structure H-2 controller design for polytopic systems via LMIs

Alireza Karimi

In this paper a new approach for fixed-structure H2 controller design in terms of solutions to a set of linear matrix inequalities are given. Both discrete- and continuous-time single-input single-output (SISO) time- invariant systems are considered. Then ...

Wiley-Blackwell2015

A totally unimodular view of structured sparsity

Volkan Cevher, Marwa El Halabi

This paper describes a simple framework for structured sparse recovery based on convex optimization. We show that many interesting structured sparsity models can be naturally represented by linear matrix inequalities on the support of the unknown parameter ...

2015

Robust Performance Analysis of Single Parameter-dependent Systems with Polynomially Parameter-dependent Lyapunov Matrices

Alireza Karimi

This paper addresses the problem of H-infinity and H-2 performance analysis of continuous-time affine single parameter-dependent systems with polynomially parameter-dependent Lyapunov matrices. First, some necessary and sufficient conditions in terms of li ...

2014

Fixed-order Discrete-time LPV Controller Design

Alireza Karimi, Zlatko Emedi

A new method for the design of fixed-order dynamic output-feedback Linear Parameter Varying (LPV) controllers for discrete-time LPV systems with bounded scheduling parameter variations is presented in this paper. Sufficient conditions for the stability, H2 ...

2014

Semisupervised Manifold Alignment of Multimodal Remote Sensing Images

Devis Tuia

We introduce a method for manifold alignment of different modalities (or domains) of remote sensing images. The problem is recurrent when a set of multitemporal, multisource, multisensor, and multiangular images is available. In these situations, images sh ...

Ieee-Inst Electrical Electronics Engineers Inc2014

Fixed-order Controller Design for State Space Polytopic Systems by Convex Optimization

Alireza Karimi

In this paper, a new method for fixed-order controller design of systems with polytopic uncertainty in their state space representation is proposed. The approach uses the strictly positive realness (SPRness) of some transfer functions, as a tool to decoupl ...

2013

Fixed-order LPV Controller Design for Rejection of a Sinusoidal Disturbance with Time-varying Frequency

Alireza Karimi, Zlatko Emedi

A new method for the design of fixed-order Linear Parameter Varying (LPV) controllers with polytopic representation for LTI plants is proposed. The stability constraints for the closed-loop system are presented through a set of Linear Matrix Inequalities ( ...

2012

Fixed-order H-infinity controller design for systems with ellipsoidal parametric uncertainty

Alireza Karimi

In this paper, fixed-order robust H-infinity controller design for systems with ellipsoidal parametric uncertainty based on parameter dependent Lyapunov functions is studied. Using the concept of Strictly Positive Realness (SPRness) of transfer functions, ...

Taylor & Francis2011

Frequency-domain analysis of ground electrodes buried in an ionized soil when subjected to surge currents: A MoM–AOM approach

Farhad Rachidi-Haeri, Keyhan Sheshyekani

A frequency-domain method is proposed for the transient analysis of grounding systems with ionized soil. The method involves two stages. First, the grounding system is transformed into a nonlinear equivalent circuit, in which the frequency-domain circuit p ...

Elsevier2011

Nilpotent subalgebras of semisimple Lie algebras

Donna Testerman

Let g be the Lie algebra of a semisimple linear algebraic group. Under mild conditions on the characteristic of the underlying field, one can show that any subalgebra of g consisting of nilpotent elements is contained in some Borel subalgebra. In this Note ...

2009

Nilpotent centralizers and Springer isomorphisms

Donna Testerman

Let GG be a semisimple algebraic group over a field KK whose characteristic is very good for GG, and let σσ be any GG-equivariant isomorphism from the nilpotent variety to the unipotent variety; the map σσ is known as a Springer isomorphism. Let y∈G(K)y∈G( ...

2009