المؤلفون: Teh-Lu Liao, Chun-Wei Kao, Hsiao-Hwa Chen, Wen-Long Chin

المصدر: IEEE Transactions on Vehicular Technology. 63:1633-1644

مصطلحات موضوعية: Computer Networks and Communications, Orthogonal frequency-division multiplexing, Aerospace Engineering, Data_CODINGANDINFORMATIONTHEORY, Synchronization, Cyclic prefix, Cognitive radio, Signal-to-noise ratio, Carrier frequency offset, Automotive Engineering, Electronic engineering, Detection theory, Electrical and Electronic Engineering, Multipath propagation, Computer Science::Information Theory, Mathematics

الوصف: Despite many attractive features of an orthogonal frequency-division multiplexing (OFDM) system, the signal detection in an OFDM system over multipath fading channels remains a challenging issue, particularly in a relatively low signal-to-noise ratio (SNR) scenario. This paper presents an iterative synchronization-assisted OFDM signal detection scheme for cognitive radio (CR) applications over multipath channels in low-SNR regions. To detect an OFDM signal, a log-likelihood ratio (LLR) test is employed without additional pilot symbols using a cyclic prefix (CP). Analytical results indicate that the LLR of received samples at a low SNR can be approximated by their log-likelihood (LL) functions, thus allowing us to estimate synchronization parameters for signal detection. The LL function is complex and depends on various parameters, including correlation coefficient, carrier frequency offset (CFO), symbol timing offset, and channel length. Decomposing a synchronization problem into several relatively simple parameter estimation subproblems eliminates a multidimensional grid search. An iterative scheme is also devised to implement a synchronization process. Simulation results confirm the effectiveness of the proposed detector.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::8b07b930d09c6a2095f2976e1c635f60Test
https://doi.org/10.1109/tvt.2013.2285389Test

المؤلفون: Teh-Lu Liao, Jun-Juh Yan, Yi-You Hou

المصدر: IEEE Transactions on Systems, Man and Cybernetics, Part B (Cybernetics). 37:720-726

مصطلحات موضوعية: Stability criterion, Stability (learning theory), Pattern Recognition, Automated, Exponential stability, Computer Science::Systems and Control, Control theory, Computer Simulation, Electrical and Electronic Engineering, Mathematics, Stochastic Processes, Models, Statistical, Linear matrix inequality, General Medicine, Fuzzy control system, Markov Chains, Computer Science Applications, Human-Computer Interaction, Nonlinear Dynamics, Takagi sugeno, Control and Systems Engineering, Fuzzy cellular neural networks, Time derivative, Neural Networks, Computer, Algorithms, Software, Information Systems

الوصف: This correspondence investigates the global exponential stability problem of Takagi-Sugeno fuzzy cellular neural networks with time-varying delays (TSFDCNNs). Based on the Lyapunov-Krasovskii functional theory and linear matrix inequality technique, a less conservative delay-dependent stability criterion is derived to guarantee the exponential stability of TSFDCNNs. By constructing a Lyapunov-Krasovskii functional, the supplementary requirement that the time derivative of time-varying delays must be smaller than one is released in the proposed delay-dependent stability criterion. Two illustrative examples are provided to verify the effectiveness of the proposed results.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7ef56bb3879031dfe9342de582ec404aTest
https://doi.org/10.1109/tsmcb.2006.889628Test

المؤلفون: Chao-Jung Cheng, Teh-Lu Liao, Jun-Juh Yan, Chi-Chuan Hwang

المصدر: IEEE Transactions on Systems, Man and Cybernetics, Part B (Cybernetics). 36:209-215

مصطلحات موضوعية: Time Factors, Models, Neurological, Computer Science::Neural and Evolutionary Computation, Synaptic Transmission, Synchronization, Algebraic Riccati equation, Matrix (mathematics), Artificial Intelligence, Biological Clocks, Control theory, Cellular neural network, ComputingMethodologies_SYMBOLICANDALGEBRAICMANIPULATION, Animals, Humans, Computer Simulation, Electrical and Electronic Engineering, Eigenvalues and eigenvectors, Mathematics, Lyapunov stability, Hamiltonian matrix, Quantitative Biology::Neurons and Cognition, Artificial neural network, General Medicine, Computer Science Applications, Human-Computer Interaction, Nonlinear Dynamics, Control and Systems Engineering, Neural Networks, Computer, Software, Information Systems

الوصف: This paper aims to present a synchronization scheme for a class of delayed neural networks, which covers the Hopfield neural networks and cellular neural networks with time-varying delays. A feedback control gain matrix is derived to achieve the exponential synchronization of the drive-response structure of neural networks by using the Lyapunov stability theory, and its exponential synchronization condition can be verified if a certain Hamiltonian matrix with no eigenvalues on the imaginary axis. This condition can avoid solving an algebraic Riccati equation. Both the cellular neural networks and Hopfield neural networks with time-varying delays are given as examples for illustration.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4550857ee1df8f15beddb89e29dec0f9Test
https://doi.org/10.1109/tsmcb.2005.856144Test

المؤلفون: Tsun-I Chien, Teh-Lu Liao

المصدر: IEEE Transactions on Automatic Control. 45:977-980

مصطلحات موضوعية: Lyapunov function, Adaptive control, Basis (linear algebra), State (functional analysis), Tracking (particle physics), Computer Science Applications, Compensation (engineering), symbols.namesake, Exponential stability, Control and Systems Engineering, Control theory, Convergence (routing), symbols, Electrical and Electronic Engineering, Mathematics

الوصف: This note presents a novel adaptive compensation scheme for Coulomb friction in a servocontrol system. An adaptive observer for estimating the unknown Coulomb friction coefficient is also derived on the basis of the Lyapunov technique. In addition, a linearizing control law is developed to compensate for the friction force and obtain the tracking objective. The proposed adaptive compensation guarantees an exponential convergence for state errors and parameter error, and known adaptive schemes guarantee only an asymptotic (or stable) convergence. Simulation results demonstrate the effectiveness of the proposed method for a single-mass servocontrol system.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::8060a2e937c1afba00ede06e986d7ed2Test
https://doi.org/10.1109/9.855565Test

المؤلفون: Fong-Chin Wang, Teh-Lu Liao

المصدر: IEEE Transactions on Neural Networks. 11:1481-1484

مصطلحات موضوعية: Equilibrium point, Signal processing, Artificial neural network, Computer Networks and Communications, Stability (learning theory), General Medicine, Application software, computer.software_genre, Computer Science Applications, Exponential stability, Artificial Intelligence, Control theory, Cellular neural network, Cellular network, computer, Software, Mathematics

الوصف: In this paper, a sufficient condition related to the existence of a unique equilibrium point and its global asymptotic stability for cellular network networks with delay (DCNNs) is derived. It is shown that the condition relies on the feedback matrices and is independent of the delay parameter. Furthermore, this condition is less restrictive than that given in the literature.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7990580f9cf58e4050933deaa7747ceeTest
https://doi.org/10.1109/72.883480Test

المؤلفون: Teh-Lu Liao, Nan-Sheng Huang

المصدر: IEEE Transactions on Circuits and Systems I: Fundamental Theory and Applications. 46:1144-1150

مصطلحات موضوعية: Nonlinear Sciences::Chaotic Dynamics, CHAOS (operating system), Chaotic masking, Control theory, Computer science, Modulation, ComputerSystemsOrganization_MISCELLANEOUS, Synchronization of chaos, Transmitter, SIGNAL (programming language), Chaotic synchronization, Electrical and Electronic Engineering, Observer based

الوصف: In this paper a systematic approach, based on the linear-state-observer design for constructing two chaotically synchronized systems, is developed. The proposed method is then applied to suggest a means to secure communications. The method combines chaotic masking and chaotic modulation, where the information signal is injected into the transmitter and simultaneously transmitted to the receiver. Furthermore, two well-known chaotic systems, Rossler and Lorenz, and a hyperchaotic Rossler system are considered as illustrative examples to demonstrate the effectiveness of the proposed approach.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::b111963ab8b79ab816565067f13be960Test
https://doi.org/10.1109/81.788817Test

المؤلفون: Teh-Lu Liao, Tsun-I Chien

المصدر: IEEE Transactions on Automatic Control ; volume 45, issue 5, page 977-980 ; ISSN 0018-9286

الإتاحة: https://doi.org/10.1109/9.855565Test
http://xplorestaging.ieee.org/ielx5/9/18579/00855565.pdf?arnumber=855565Test