Magazine et Edition

Volume 32 (2022): Edition 3 (September 2022)
Recent Advances in Modelling, Analysis and Implementation of Cyber-Physical Systems (Special section, pp. 345-413), Remigiusz Wiśniewski, Luis Gomes and Shaohua Wan (Eds.)

Volume 32 (2022): Edition 2 (June 2022)
Towards Self-Healing Systems through Diagnostics, Fault-Tolerance and Design (Special section, pp. 171-269), Marcin Witczak and Ralf Stetter (Eds.)

Volume 32 (2022): Edition 1 (March 2022)

Volume 31 (2021): Edition 4 (December 2021)
Advanced Machine Learning Techniques in Data Analysis (special section, pp. 549-611), Maciej Kusy, Rafał Scherer, and Adam Krzyżak (Eds.)

Volume 31 (2021): Edition 3 (September 2021)

Volume 31 (2021): Edition 2 (June 2021)

Volume 31 (2021): Edition 1 (March 2021)

Volume 30 (2020): Edition 4 (December 2020)

Volume 30 (2020): Edition 3 (September 2020)
Big Data and Signal Processing (Special section, pp. 399-473), Joanna Kołodziej, Sabri Pllana, Salvatore Vitabile (Eds.)

Volume 30 (2020): Edition 2 (June 2020)

Volume 30 (2020): Edition 1 (March 2020)

Volume 29 (2019): Edition 4 (December 2019)
New Perspectives in Nonlinear and Intelligent Control (In Honor of Alexander P. Kurdyukov) (special section, pp. 629-712), Julio B. Clempner, Enso Ikonen, Alexander P. Kurdyukov (Eds.)

Volume 29 (2019): Edition 3 (September 2019)
Information Technology for Systems Research (special section, pp. 427-515), Piotr Kulczycki, Janusz Kacprzyk, László T. Kóczy, Radko Mesiar (Eds.)

Volume 29 (2019): Edition 2 (June 2019)
Advances in Complex Cloud and Service Oriented Computing (special section, pp. 213-274), Anna Kobusińska, Ching-Hsien Hsu, Kwei-Jay Lin (Eds.)

Volume 29 (2019): Edition 1 (March 2019)
Exploring Complex and Big Data (special section, pp. 7-91), Johann Gamper, Robert Wrembel (Eds.)

Volume 28 (2018): Edition 4 (December 2018)

Volume 28 (2018): Edition 3 (September 2018)

Volume 28 (2018): Edition 2 (June 2018)
Advanced Diagnosis and Fault-Tolerant Control Methods (special section, pp. 233-333), Vicenç Puig, Dominique Sauter, Christophe Aubrun, Horst Schulte (Eds.)

Volume 28 (2018): Edition 1 (March 2018)
Editions in Parameter Identification and Control (special section, pp. 9-122), Abdel Aitouche (Ed.)

Volume 27 (2017): Edition 4 (December 2017)

Volume 27 (2017): Edition 3 (September 2017)
Systems Analysis: Modeling and Control (special section, pp. 457-499), Vyacheslav Maksimov and Boris Mordukhovich (Eds.)

Volume 27 (2017): Edition 2 (June 2017)

Volume 27 (2017): Edition 1 (March 2017)

Volume 26 (2016): Edition 4 (December 2016)

Volume 26 (2016): Edition 3 (September 2016)

Volume 26 (2016): Edition 2 (June 2016)

Volume 26 (2016): Edition 1 (March 2016)

Volume 25 (2015): Edition 4 (December 2015)
Special issue: Complex Problems in High-Performance Computing Systems, Editors: Mauro Iacono, Joanna Kołodziej

Volume 25 (2015): Edition 3 (September 2015)

Volume 25 (2015): Edition 2 (June 2015)

Volume 25 (2015): Edition 1 (March 2015)
Safety, Fault Diagnosis and Fault Tolerant Control in Aerospace Systems, Silvio Simani, Paolo Castaldi (Eds.)

Volume 24 (2014): Edition 4 (December 2014)

Volume 24 (2014): Edition 3 (September 2014)
Modelling and Simulation of High Performance Information Systems (special section, pp. 453-566), Pavel Abaev, Rostislav Razumchik, Joanna Kołodziej (Eds.)

Volume 24 (2014): Edition 2 (June 2014)
Signals and Systems (special section, pp. 233-312), Ryszard Makowski and Jan Zarzycki (Eds.)

Volume 24 (2014): Edition 1 (March 2014)
Selected Problems of Biomedical Engineering (special section, pp. 7 - 63), Marek Kowal and Józef Korbicz (Eds.)

Volume 23 (2013): Edition 4 (December 2013)

Volume 23 (2013): Edition 3 (September 2013)

Volume 23 (2013): Edition 2 (June 2013)

Volume 23 (2013): Edition 1 (March 2013)

Volume 22 (2012): Edition 4 (December 2012)
Hybrid and Ensemble Methods in Machine Learning (special section, pp. 787 - 881), Oscar Cordón and Przemysław Kazienko (Eds.)

Volume 22 (2012): Edition 3 (September 2012)

Volume 22 (2012): Edition 2 (June 2012)
Analysis and Control of Spatiotemporal Dynamic Systems (special section, pp. 245 - 326), Dariusz Uciński and Józef Korbicz (Eds.)

Volume 22 (2012): Edition 1 (March 2012)
Advances in Control and Fault-Tolerant Systems (special issue), Józef Korbicz, Didier Maquin and Didier Theilliol (Eds.)

Volume 21 (2011): Edition 4 (December 2011)

Volume 21 (2011): Edition 3 (September 2011)
Editions in Advanced Control and Diagnosis (special section, pp. 423 - 486), Vicenç Puig and Marcin Witczak (Eds.)

Volume 21 (2011): Edition 2 (June 2011)
Efficient Resource Management for Grid-Enabled Applications (special section, pp. 219 - 306), Joanna Kołodziej and Fatos Xhafa (Eds.)

Volume 21 (2011): Edition 1 (March 2011)
Semantic Knowledge Engineering (special section, pp. 9 - 95), Grzegorz J. Nalepa and Antoni Ligęza (Eds.)

Volume 20 (2010): Edition 4 (December 2010)

Volume 20 (2010): Edition 3 (September 2010)

Volume 20 (2010): Edition 2 (June 2010)

Volume 20 (2010): Edition 1 (March 2010)
Computational Intelligence in Modern Control Systems (special section, pp. 7 - 84), Józef Korbicz and Dariusz Uciński (Eds.)

Volume 19 (2009): Edition 4 (December 2009)
Robot Control Theory (special section, pp. 519 - 588), Cezary Zieliński (Ed.)

Volume 19 (2009): Edition 3 (September 2009)
Verified Methods: Applications in Medicine and Engineering (special issue), Andreas Rauh, Ekaterina Auer, Eberhard P. Hofer and Wolfram Luther (Eds.)

Volume 19 (2009): Edition 2 (June 2009)

Volume 19 (2009): Edition 1 (March 2009)

Volume 18 (2008): Edition 4 (December 2008)
Editions in Fault Diagnosis and Fault Tolerant Control (special issue), Józef Korbicz and Dominique Sauter (Eds.)

Volume 18 (2008): Edition 3 (September 2008)
Selected Problems of Computer Science and Control (special issue), Krzysztof Gałkowski, Eric Rogers and Jan Willems (Eds.)

Volume 18 (2008): Edition 2 (June 2008)
Selected Topics in Biological Cybernetics (special section, pp. 117 - 170), Andrzej Kasiński and Filip Ponulak (Eds.)

Volume 18 (2008): Edition 1 (March 2008)
Applied Image Processing (special issue), Anton Kummert and Ewaryst Rafajłowicz (Eds.)

Volume 17 (2007): Edition 4 (December 2007)

Volume 17 (2007): Edition 3 (September 2007)
Scientific Computation for Fluid Mechanics and Hyperbolic Systems (special issue), Jan Sokołowski and Eric Sonnendrücker (Eds.)

Volume 17 (2007): Edition 2 (June 2007)

Volume 17 (2007): Edition 1 (March 2007)

Détails du magazine
Format
Magazine
eISSN
2083-8492
Première publication
05 Apr 2007
Période de publication
4 fois par an
Langues
Anglais

Chercher

Volume 31 (2021): Edition 2 (June 2021)

Détails du magazine
Format
Magazine
eISSN
2083-8492
Première publication
05 Apr 2007
Période de publication
4 fois par an
Langues
Anglais

Chercher

12 Articles
Accès libre

On a stable solution of the problem of disturbance reduction

Publié en ligne: 08 Jul 2021
Pages: 187 - 194

Résumé

Abstract

We study the problem of active reduction of the influence of a disturbance on the output of a linear control system. We consider a system of linear differential equations under the action of an unknown disturbance and a control to be formed. Our goal is to design an algorithm for reducing the disturbance by means of an appropriate control on the basis of inaccurate measurements of the system phase coordinates. This algorithm should form a feedback control that would guarantee that the trajectory of a given system tracks the trajectory of the reference system, i.e., the system described by the same differential equations but with zero control and disturbance. We present an algorithm for solving this problem. The algorithm, based on the constructions of guaranteed control theory, is stable with respect to informational noises and computational errors.

Mots clés

  • disturbance reduction
  • dynamical controlled system
  • guaranteed control theory
Accès libre

Comparison of direct and perturbation approaches to analysis of infinite–dimensional feedback control systems

Publié en ligne: 08 Jul 2021
Pages: 195 - 218

Résumé

Abstract

For general boundary control systems in factor form some necessary and sufficient conditions for generation of an analytic exponentially stable semigroup are proposed in both direct and perturbation forms for comparison. The direct approach is applicable to operators with the numerical range satisfying certain additional conditions. In particular, it applies to operators similar to convexoids and therefore it generalizes previous results known for hyponormal operators. The perturbation result (indirect approach) is derived and formulated as an exponential stability robustness result using the frequence-domain considerations. It is expressed in terms of some estimates of the resolvent growth over the open right complex half-plane and compared with some recent results. The analysis is illustrated in detail with examples of an unloaded and loaded electric RC-transmission line with proportional negative feedback.

Mots clés

  • perturbation
  • semigroups
  • systems in factor form
  • spectral operators
Accès libre

Mittag-Leffler stability for a Timoshenko problem

Publié en ligne: 08 Jul 2021
Pages: 219 - 232

Résumé

Abstract

A Timoshenko system of a fractional order between zero and one is investigated here. Using a fractional version of resolvents, we establish an existence and uniqueness theorem in an appropriate space. Moreover, it is proved that lower order fractional terms (in the rotation component) are capable of stabilizing the system in a Mittag-Leffler fashion. Therefore, they deserve to be called damping terms. This is shown through the introduction of some new functionals and some fractional inequalities, and the establishment of some properties, involving fractional derivatives. In the case of different wave speeds of propagation we obtain convergence to zero.

Mots clés

  • Caputo fractional derivative
  • Mittag-Leffler stability
  • multiplier technique
  • resolvent operator
Accès libre

A mixed type boundary–value problem related to the electrostatics of cold plasma jet reactors based on dielectric barrier discharge

Publié en ligne: 08 Jul 2021
Pages: 233 - 245

Résumé

Abstract

A semi-analytical model is presented for the determination of the electric field in reactors used for cold atmospheric pressure plasma (CAPP) jet production, based on the concept of dielectric barrier discharge (DBD). These systems are associated with various applications in contemporary engineering, ranging from material processing to biomedicine, and at the same time they provide many challenges for fundamental research. Here, we consider a simplified system configuration of a single driven electrode, surrounding a thin dielectric tube, which does not contribute to the electric field, since the potential variation is immediate due to its negligible size. By employing the cylindrical coordinate system that perfectly fits the present plasma jet reactor, we separate the area of electric activity into three distinct domains according to the imposed external conditions, while our analysis is restricted to the electrostatic limit of Maxwell’s equations. To this end, cylindrical harmonic field expansions are used for the potential, which produce the corresponding electric fields in each subdomain. Due to the imposed mixed-type boundary value problem, additional linear terms are incorporated, leading to three possible analytical solutions of the physical problem under consideration. The efficiency of the method is demonstrated by comparing the final formulae with a numerical solution, followed by the relevant discussion.

Mots clés

  • DBD
  • cold plasma jet
  • reactor
  • mixed-type boundary-value problem
  • electrostatic potential theory
Accès libre

A fault estimation and fault–tolerant control based sliding mode observer for LPV descriptor systems with time delay

Publié en ligne: 08 Jul 2021
Pages: 247 - 258

Résumé

Abstract

This paper considers the problem of fault-tolerant control (FTC) and fault reconstruction of actuator faults for linear parameter varying (LPV) descriptor systems with time delay. A polytopic sliding mode observer (PSMO) is synthesized to achieve simultaneous reconstruction of LPV polytopic descriptor system states and actuator faults. Exploiting the reconstructed actuator faults and state estimates, a fault-tolerant controller is designed to compensate the impact of actuator faults on system performance by stabilizing the closed-loop LPV delayed descriptor system. Besides, the controller and PSMO gains are obtained throughout the resolution of linear matrix inequalities (LMIs) using convex optimization techniques. The developed PSMO could force the output estimation error to converge to zero in a finite time when the actuators faults are bounded through the reinjection of the output estimation error via a nonlinear switching term. Simulation results applied to a given numerical system are presented to highlight the superiority and effectiveness of the proposed approach.

Mots clés

  • fault estimation
  • fault-tolerant control
  • LPV descriptor systems
  • sliding mode observer
  • time delay
  • LMIs
Accès libre

An interval Kalman filter enhanced by lowering the covariance matrix upper bound

Publié en ligne: 08 Jul 2021
Pages: 259 - 269

Résumé

Abstract

This paper proposes a variance upper bound based interval Kalman filter that enhances the interval Kalman filter based on the same principle proposed by Tran et al. (2017) for uncertain discrete time linear models. The systems under consideration are subject to bounded parameter uncertainties not only in the state and observation matrices, but also in the covariance matrices of the Gaussian noises. By using the spectral decomposition of a symmetric matrix and by optimizing the gain matrix of the proposed filter, we lower the minimal upper bound on the state estimation error covariance for all admissible uncertainties. This paper contributes with an improved algorithm that provides a less conservative error covariance upper bound than the approach proposed by Tran et al. (2017). The state estimates are determined using interval analysis in order to enclose the set of all possible solutions of the classical Kalman filter consistent with the uncertainties.

Mots clés

  • uncertain linear systems
  • Kalman filter
  • interval analysis
  • estimation
  • covariance matrix
Accès libre

Dynamic location models of mobile sensors for travel time estimation on a freeway

Publié en ligne: 08 Jul 2021
Pages: 271 - 287

Résumé

Abstract

Travel time estimation for freeways has attracted much attention from researchers and traffic management departments. Because of various uncertain factors, travel time on a freeway is stochastic. To obtain travel time estimates for a freeway accurately, this paper proposes two traffic sensor location models that consider minimizing the error of travel time estimation and maximizing the collected traffic flow. First, a dynamic optimal location model of the mobile sensor is proposed under the assumption that there are no traffic sensors on a freeway. Next, a dynamic optimal combinatorial model of adding mobile sensors taking account of fixed sensors on a freeway is presented. It should be pointed out that the technology of data fusion will be adopted to tackle the collected data from multiple sensors in the second optimization model. Then, a simulated annealing algorithm is established to find the solutions of the proposed two optimization models. Numerical examples demonstrate that dynamic optimization of mobile sensor locations for the estimation of travel times on a freeway is more accurate than the conventional location model.

Mots clés

  • traffic mobile sensor
  • dynamic location model
  • travel time estimation
  • simulated annealing algorithm
  • data fusion
Accès libre

Path planning for an autonomous underwater vehicle in a cluttered underwater environment based on the heat method

Publié en ligne: 08 Jul 2021
Pages: 289 - 301

Résumé

Abstract

This paper proposes a novel autonomous underwater vehicle path planning algorithm in a cluttered underwater environment based on the heat method. The algorithm calculates the isotropic and anisotropic geodesic distances by adding the direction and magnitude of the currents to the heat method, which is named the anisotropy-based heat method. Taking account of the relevant influence of the environment on the cost functions, such as currents, obstacles and turn of the vehicle, an efficient collision-free and energy-optimized path solution can be obtained. Simulation results show that the anisotropy-based heat method is able to find a good trajectory in both static and dynamic clutter fields (including uncertain obstacles and changing currents). Compared with the fast marching (FM) algorithm, the anisotropy-based heat method is not only robust, flexible, and simple to implement, but it also greatly saves time consumption and memory footprint in a time-variant environment. Finally, the evaluation criteria of paths are proposed in terms of length, arrival time, energy consumption, and smoothness.

Mots clés

  • autonomous underwater vehicle
  • path planning
  • heat method
  • heat diffusion
  • cost function
Accès libre

An outlier–robust neuro–fuzzy system for classification and regression

Publié en ligne: 08 Jul 2021
Pages: 303 - 319

Résumé

Abstract

Real life data often suffer from non-informative objects—outliers. These are objects that are not typical in a dataset and can significantly decline the efficacy of fuzzy models. In the paper we analyse neuro-fuzzy systems robust to outliers in classification and regression tasks. We use the fuzzy c-ordered means (FCOM) clustering algorithm for scatter domain partition to identify premises of fuzzy rules. The clustering algorithm elaborates typicality of each object. Data items with low typicalities are removed from further analysis. The paper is accompanied by experiments that show the efficacy of our modified neuro-fuzzy system to identify fuzzy models robust to high ratios of outliers.

Mots clés

  • outliers
  • neuro-fuzzy systems
  • clustering
  • classification
  • regression
Accès libre

Data–driven online modelling for a UGI gasification process using modified lazy learning with a relevance vector machine

Publié en ligne: 08 Jul 2021
Pages: 321 - 335

Résumé

Abstract

A modified lazy learning algorithm combined with a relevance vector machine (MLL-RVM) is presented to address a data-driven modelling problem for a gasification process inside a united gas improvement (UGI) gasifier. During the UGI gasification process, the measured online temperature of the produced crude gas is a crucial aspect. However, the gasification process complexities, especially severe changes in the temperature versus infrequent manipulation of the gasifier and the unknown noise in collected data, pose difficulties in dynamics process descriptions via conventional first principles. In the MLL-RVM, a novel weighted neighbour selection method is adopted based on the proposed dynamic cost functions. Moreover, the RVM is utilized in the implementation and design of the proposed online local modelling owing to its short test time and sparseness. Furthermore, the leave-one-out cross-validation technique is used for local model validation, by which the modelling performance is further improved. The MLL-RVM is applied to a series of real data collected from a pragmatic UGI gasifier, and its effectiveness is verified.

Mots clés

  • data-driven modelling
  • UGI gasification process
  • relevance vector machine
  • modified lazy learning
Accès libre

Minimal state automata for detecting a β globin gene mutation

Publié en ligne: 08 Jul 2021
Pages: 337 - 351

Résumé

Abstract

Beta-thalassemia is an autosomal recessive blood disorder characterized by abnormalities in the synthesis of β globin. Together with α globin, it is a subunit of globin protein, called hemoglobin, located inside our red blood cells to deliver oxygen from the lungs to all of the tissues throughout our body. Thereby, individuals with β-thalassemia will often feel limp due to a lack of oxygen dissolved in their blood. In this paper, a finite state automaton to detect and classify β globin gene mutations using its DNA sequence is constructed. Finite state automata have a close connection to an algebraic structure, that is, a monoid. Together with the theory of the syntactic monoid, we present a methodology to minimize the number of the internal states of an automaton to have minimal state automata. Therefore, a minimal state automaton can be constructed to detect β globin gene mutation causing the β-thalassemia disease. We have developed a MATLAB program to conduct the appropriate simulations.

Mots clés

  • minimal state automata
  • syntactic monoid
  • -thalassemia
  • biological sequences
Accès libre

A decentralized group signature scheme for privacy protection in a blockchain

Publié en ligne: 08 Jul 2021
Pages: 353 - 364

Résumé

Abstract

Group signature schemes play a vital role in protecting identity privacy of a member of a group who signs a message using the group signature. However, in the existing group signature schemes the centralized group manager has control over all the participants, and these managers can be malicious. They may take a biased decision when there is a dispute among the group members or while revealing the identity of a group member. To overcome the trust issues related to centralized group managers and to improve user privacy, a decentralized group signature scheme (DGSS) is proposed by decentralizing the role of the group manager. The proposed scheme will be more suitable for decentralized environments like a blockchain. Security analysis along with the proof of correctness is also provided for the proposed scheme. A framework for a blockchain-based e-auction protocol using the DGSS is also proposed in this paper.

Mots clés

  • blockchain
  • decentralization
  • e-auction
  • group signature
  • privacy
  • smart contract
12 Articles
Accès libre

On a stable solution of the problem of disturbance reduction

Publié en ligne: 08 Jul 2021
Pages: 187 - 194

Résumé

Abstract

We study the problem of active reduction of the influence of a disturbance on the output of a linear control system. We consider a system of linear differential equations under the action of an unknown disturbance and a control to be formed. Our goal is to design an algorithm for reducing the disturbance by means of an appropriate control on the basis of inaccurate measurements of the system phase coordinates. This algorithm should form a feedback control that would guarantee that the trajectory of a given system tracks the trajectory of the reference system, i.e., the system described by the same differential equations but with zero control and disturbance. We present an algorithm for solving this problem. The algorithm, based on the constructions of guaranteed control theory, is stable with respect to informational noises and computational errors.

Mots clés

  • disturbance reduction
  • dynamical controlled system
  • guaranteed control theory
Accès libre

Comparison of direct and perturbation approaches to analysis of infinite–dimensional feedback control systems

Publié en ligne: 08 Jul 2021
Pages: 195 - 218

Résumé

Abstract

For general boundary control systems in factor form some necessary and sufficient conditions for generation of an analytic exponentially stable semigroup are proposed in both direct and perturbation forms for comparison. The direct approach is applicable to operators with the numerical range satisfying certain additional conditions. In particular, it applies to operators similar to convexoids and therefore it generalizes previous results known for hyponormal operators. The perturbation result (indirect approach) is derived and formulated as an exponential stability robustness result using the frequence-domain considerations. It is expressed in terms of some estimates of the resolvent growth over the open right complex half-plane and compared with some recent results. The analysis is illustrated in detail with examples of an unloaded and loaded electric RC-transmission line with proportional negative feedback.

Mots clés

  • perturbation
  • semigroups
  • systems in factor form
  • spectral operators
Accès libre

Mittag-Leffler stability for a Timoshenko problem

Publié en ligne: 08 Jul 2021
Pages: 219 - 232

Résumé

Abstract

A Timoshenko system of a fractional order between zero and one is investigated here. Using a fractional version of resolvents, we establish an existence and uniqueness theorem in an appropriate space. Moreover, it is proved that lower order fractional terms (in the rotation component) are capable of stabilizing the system in a Mittag-Leffler fashion. Therefore, they deserve to be called damping terms. This is shown through the introduction of some new functionals and some fractional inequalities, and the establishment of some properties, involving fractional derivatives. In the case of different wave speeds of propagation we obtain convergence to zero.

Mots clés

  • Caputo fractional derivative
  • Mittag-Leffler stability
  • multiplier technique
  • resolvent operator
Accès libre

A mixed type boundary–value problem related to the electrostatics of cold plasma jet reactors based on dielectric barrier discharge

Publié en ligne: 08 Jul 2021
Pages: 233 - 245

Résumé

Abstract

A semi-analytical model is presented for the determination of the electric field in reactors used for cold atmospheric pressure plasma (CAPP) jet production, based on the concept of dielectric barrier discharge (DBD). These systems are associated with various applications in contemporary engineering, ranging from material processing to biomedicine, and at the same time they provide many challenges for fundamental research. Here, we consider a simplified system configuration of a single driven electrode, surrounding a thin dielectric tube, which does not contribute to the electric field, since the potential variation is immediate due to its negligible size. By employing the cylindrical coordinate system that perfectly fits the present plasma jet reactor, we separate the area of electric activity into three distinct domains according to the imposed external conditions, while our analysis is restricted to the electrostatic limit of Maxwell’s equations. To this end, cylindrical harmonic field expansions are used for the potential, which produce the corresponding electric fields in each subdomain. Due to the imposed mixed-type boundary value problem, additional linear terms are incorporated, leading to three possible analytical solutions of the physical problem under consideration. The efficiency of the method is demonstrated by comparing the final formulae with a numerical solution, followed by the relevant discussion.

Mots clés

  • DBD
  • cold plasma jet
  • reactor
  • mixed-type boundary-value problem
  • electrostatic potential theory
Accès libre

A fault estimation and fault–tolerant control based sliding mode observer for LPV descriptor systems with time delay

Publié en ligne: 08 Jul 2021
Pages: 247 - 258

Résumé

Abstract

This paper considers the problem of fault-tolerant control (FTC) and fault reconstruction of actuator faults for linear parameter varying (LPV) descriptor systems with time delay. A polytopic sliding mode observer (PSMO) is synthesized to achieve simultaneous reconstruction of LPV polytopic descriptor system states and actuator faults. Exploiting the reconstructed actuator faults and state estimates, a fault-tolerant controller is designed to compensate the impact of actuator faults on system performance by stabilizing the closed-loop LPV delayed descriptor system. Besides, the controller and PSMO gains are obtained throughout the resolution of linear matrix inequalities (LMIs) using convex optimization techniques. The developed PSMO could force the output estimation error to converge to zero in a finite time when the actuators faults are bounded through the reinjection of the output estimation error via a nonlinear switching term. Simulation results applied to a given numerical system are presented to highlight the superiority and effectiveness of the proposed approach.

Mots clés

  • fault estimation
  • fault-tolerant control
  • LPV descriptor systems
  • sliding mode observer
  • time delay
  • LMIs
Accès libre

An interval Kalman filter enhanced by lowering the covariance matrix upper bound

Publié en ligne: 08 Jul 2021
Pages: 259 - 269

Résumé

Abstract

This paper proposes a variance upper bound based interval Kalman filter that enhances the interval Kalman filter based on the same principle proposed by Tran et al. (2017) for uncertain discrete time linear models. The systems under consideration are subject to bounded parameter uncertainties not only in the state and observation matrices, but also in the covariance matrices of the Gaussian noises. By using the spectral decomposition of a symmetric matrix and by optimizing the gain matrix of the proposed filter, we lower the minimal upper bound on the state estimation error covariance for all admissible uncertainties. This paper contributes with an improved algorithm that provides a less conservative error covariance upper bound than the approach proposed by Tran et al. (2017). The state estimates are determined using interval analysis in order to enclose the set of all possible solutions of the classical Kalman filter consistent with the uncertainties.

Mots clés

  • uncertain linear systems
  • Kalman filter
  • interval analysis
  • estimation
  • covariance matrix
Accès libre

Dynamic location models of mobile sensors for travel time estimation on a freeway

Publié en ligne: 08 Jul 2021
Pages: 271 - 287

Résumé

Abstract

Travel time estimation for freeways has attracted much attention from researchers and traffic management departments. Because of various uncertain factors, travel time on a freeway is stochastic. To obtain travel time estimates for a freeway accurately, this paper proposes two traffic sensor location models that consider minimizing the error of travel time estimation and maximizing the collected traffic flow. First, a dynamic optimal location model of the mobile sensor is proposed under the assumption that there are no traffic sensors on a freeway. Next, a dynamic optimal combinatorial model of adding mobile sensors taking account of fixed sensors on a freeway is presented. It should be pointed out that the technology of data fusion will be adopted to tackle the collected data from multiple sensors in the second optimization model. Then, a simulated annealing algorithm is established to find the solutions of the proposed two optimization models. Numerical examples demonstrate that dynamic optimization of mobile sensor locations for the estimation of travel times on a freeway is more accurate than the conventional location model.

Mots clés

  • traffic mobile sensor
  • dynamic location model
  • travel time estimation
  • simulated annealing algorithm
  • data fusion
Accès libre

Path planning for an autonomous underwater vehicle in a cluttered underwater environment based on the heat method

Publié en ligne: 08 Jul 2021
Pages: 289 - 301

Résumé

Abstract

This paper proposes a novel autonomous underwater vehicle path planning algorithm in a cluttered underwater environment based on the heat method. The algorithm calculates the isotropic and anisotropic geodesic distances by adding the direction and magnitude of the currents to the heat method, which is named the anisotropy-based heat method. Taking account of the relevant influence of the environment on the cost functions, such as currents, obstacles and turn of the vehicle, an efficient collision-free and energy-optimized path solution can be obtained. Simulation results show that the anisotropy-based heat method is able to find a good trajectory in both static and dynamic clutter fields (including uncertain obstacles and changing currents). Compared with the fast marching (FM) algorithm, the anisotropy-based heat method is not only robust, flexible, and simple to implement, but it also greatly saves time consumption and memory footprint in a time-variant environment. Finally, the evaluation criteria of paths are proposed in terms of length, arrival time, energy consumption, and smoothness.

Mots clés

  • autonomous underwater vehicle
  • path planning
  • heat method
  • heat diffusion
  • cost function
Accès libre

An outlier–robust neuro–fuzzy system for classification and regression

Publié en ligne: 08 Jul 2021
Pages: 303 - 319

Résumé

Abstract

Real life data often suffer from non-informative objects—outliers. These are objects that are not typical in a dataset and can significantly decline the efficacy of fuzzy models. In the paper we analyse neuro-fuzzy systems robust to outliers in classification and regression tasks. We use the fuzzy c-ordered means (FCOM) clustering algorithm for scatter domain partition to identify premises of fuzzy rules. The clustering algorithm elaborates typicality of each object. Data items with low typicalities are removed from further analysis. The paper is accompanied by experiments that show the efficacy of our modified neuro-fuzzy system to identify fuzzy models robust to high ratios of outliers.

Mots clés

  • outliers
  • neuro-fuzzy systems
  • clustering
  • classification
  • regression
Accès libre

Data–driven online modelling for a UGI gasification process using modified lazy learning with a relevance vector machine

Publié en ligne: 08 Jul 2021
Pages: 321 - 335

Résumé

Abstract

A modified lazy learning algorithm combined with a relevance vector machine (MLL-RVM) is presented to address a data-driven modelling problem for a gasification process inside a united gas improvement (UGI) gasifier. During the UGI gasification process, the measured online temperature of the produced crude gas is a crucial aspect. However, the gasification process complexities, especially severe changes in the temperature versus infrequent manipulation of the gasifier and the unknown noise in collected data, pose difficulties in dynamics process descriptions via conventional first principles. In the MLL-RVM, a novel weighted neighbour selection method is adopted based on the proposed dynamic cost functions. Moreover, the RVM is utilized in the implementation and design of the proposed online local modelling owing to its short test time and sparseness. Furthermore, the leave-one-out cross-validation technique is used for local model validation, by which the modelling performance is further improved. The MLL-RVM is applied to a series of real data collected from a pragmatic UGI gasifier, and its effectiveness is verified.

Mots clés

  • data-driven modelling
  • UGI gasification process
  • relevance vector machine
  • modified lazy learning
Accès libre

Minimal state automata for detecting a β globin gene mutation

Publié en ligne: 08 Jul 2021
Pages: 337 - 351

Résumé

Abstract

Beta-thalassemia is an autosomal recessive blood disorder characterized by abnormalities in the synthesis of β globin. Together with α globin, it is a subunit of globin protein, called hemoglobin, located inside our red blood cells to deliver oxygen from the lungs to all of the tissues throughout our body. Thereby, individuals with β-thalassemia will often feel limp due to a lack of oxygen dissolved in their blood. In this paper, a finite state automaton to detect and classify β globin gene mutations using its DNA sequence is constructed. Finite state automata have a close connection to an algebraic structure, that is, a monoid. Together with the theory of the syntactic monoid, we present a methodology to minimize the number of the internal states of an automaton to have minimal state automata. Therefore, a minimal state automaton can be constructed to detect β globin gene mutation causing the β-thalassemia disease. We have developed a MATLAB program to conduct the appropriate simulations.

Mots clés

  • minimal state automata
  • syntactic monoid
  • -thalassemia
  • biological sequences
Accès libre

A decentralized group signature scheme for privacy protection in a blockchain

Publié en ligne: 08 Jul 2021
Pages: 353 - 364

Résumé

Abstract

Group signature schemes play a vital role in protecting identity privacy of a member of a group who signs a message using the group signature. However, in the existing group signature schemes the centralized group manager has control over all the participants, and these managers can be malicious. They may take a biased decision when there is a dispute among the group members or while revealing the identity of a group member. To overcome the trust issues related to centralized group managers and to improve user privacy, a decentralized group signature scheme (DGSS) is proposed by decentralizing the role of the group manager. The proposed scheme will be more suitable for decentralized environments like a blockchain. Security analysis along with the proof of correctness is also provided for the proposed scheme. A framework for a blockchain-based e-auction protocol using the DGSS is also proposed in this paper.

Mots clés

  • blockchain
  • decentralization
  • e-auction
  • group signature
  • privacy
  • smart contract

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