Chaos Synchronization Using Adaptive Dynamic Neural Network Controller with Variable Learning Rates

This paper addresses the synchronization of chaotic gyros with unknown parameters and external disturbance via an adaptive dynamic neural network control (ADNNC) system. The proposed ADNNC system is composed of a neural controller and a smooth compensator. The neural controller uses a dynamic RBF (DRBF) network to online approximate an ideal controller. The DRBF network can create new hidden neurons online if the input data falls outside the hidden layer and prune the insignificant hidden neurons online if the hidden neuron is inappropriate. The smooth compensator is designed to compensate for the approximation error between the neural controller and the ideal controller. Moreover, the variable learning rates of the parameter adaptation laws are derived based on a discrete-type Lyapunov function to speed up the convergence rate of the tracking error. Finally, the simulation results which verified the chaotic behavior of two nonlinear identical chaotic gyros can be synchronized using the proposed ADNNC scheme

Journal of Telecommunications and Information Technology, nr 4

kwartalni

ESSE 2017. Proceedings of the International Conference on Environmental Science and Sustainable Energy

Environmental science is an interdisciplinary academic field that integrates physical-, biological-, and information sciences to study and solve environmental problems. ESSE - The International Conference on Environmental Science and Sustainable Energy provides a platform for experts, professionals, and researchers to share updated information and stimulate the communication with each other. In 2017 it was held in Suzhou, China June 23-25, 2017

NASA Tech Briefs, December 1994

Topics: Test and Measurement; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Report

Impact of environmental risk factors for schizophrenia on the developing brain, characterisation of the effects of polyIC and THC on functional neural systems and behaviour

Strathclyde theses - ask staff. Thesis no. : T13455Cannabis abuse can produce deficits in cognition and has been implicated as a 'late' environmental risk factor in the pathogenesis of the poly-factorial disorder schizophrenia. Evidence suggests an age-related susceptibility to the deleterious effects of cannabis as early onset of use may increase the vulnerability of the brain to the adverse consequences of cannabis abuse. Animal models are crucial for exploration of mechanistic and causative theories, and long-term behavioural consequences of adolescent cannabis abuse in a controlled experimental environment. This thesis evaluates the vulnerability of the adolescent/peripubertal brain to Δ9-tetrahydrocannabinol (THC), the principal psychoactive constituent of cannabis, and explores the potential interplay between this schizophrenia-related 'late' environmental risk factor and an 'early' environmental risk factor (prenatal infection - maternal immune activation (MIA)) on functional neural systems and behaviours relevant to schizophrenia. Cannabinoid CB1 receptor ontogeny (activated in the brain by the receptor ligand THC) within important cognitive substrates, the prefrontal cortex (PFC) and hippocampus, was investigated to delineate a period of neurodevelopmental vulnerability for peripubertal THC treatment. CB1 receptor ligand binding revealed that the PFC and hippocampus follow differential late maturational trajectories throughout the peripubertal period. The 'vulnerability window' for peripubertal THC treatment was defined as post-natal day (PD) 35-56 to encompass the dynamic peripubertal ontogenetic patterns of the CB1 receptor in both these regions. Furthermore, age-related alterations in cerebral metabolism and regional functional connectivity profiles were evident in the hippocampus and important neuromodulatory nuclei including the ventral tegmental area, dorsal raphe, locus coeruleus and the diagonal band of Broca.;Acute THC administration (5mg/kg) produced hypometabolism in the thalamus and an altered functional connectivity profile between thalamic nuclei and the PFC, hippocampus and the nucleus accumbens. THC-induced anomalistic neural activity was evident in key neuromodulatory nuclei and produced perturbed functional connectivity within acetylcholine, noradrenaline, and dopamine neural pathways. Acute THC treatment resulted in alterations in cerebral metabolism in the amygdala and aberrant functional connectivity profiles between amygdaloid nuclei and the hippocampus, PFC and nucleus accumbens. There appeared to be an age-related sensitivity to THC in several thalamic, neuromodulatory and amygdaloid nuclei. Peripubertal low-dose intermittent THC (3.5mg/kg, 3 times a week), mimetic of light, recreational adolescent cannabis use, produced long-term cognitive inflexibility, as measured by the attentional-set shifting task, perturbed cerebral metabolism in the dorsolateral orbital cortex and the nucleus accumbens core and altered functional coupling between both these regions and neural substrates subserving reward-related learning including prefrontal, septal and amygdala subfields. High-dose daily THC (7mg/kg) throughout the peripubertal period, mimetic of heavy daily cannabis abuse, did not precipitate any schizophrenia-related behaviours in adulthood. MIA induced by prenatal exposure to the immune-stimulating agent polyriboinosinic-polyribocytidilic acid (PolyIC) did not produce any schizophrenia-related phenotypes in adulthood. However, prenatal PolyIC exposure produced residual hypermetabolism within discrete components of the prefrontal cortex dorsolateral orbital and cingulate cortices and hypometabolism within the CA3 subfield of the hippocampus. The functional connectivity signatures of all these regions indicated a unified MIA effect of aberrant mesocorticolimbic functional coupling in adulthood. Furthermore, chronic intermittent treatment with low-dose THC during the peripubertal period caused an increase in sensitivity to amphetamine (indicative of aberrant mesolimbic dopamine transmission) in PolyIC-treated offspring compared to PBS-treated offspring, suggestive of a synergistic effect of these two environmental risk factors. In conclusion, the findings presented in this thesis have provided clear evidence of dose-specific detrimental effects of 'adolescent' THC exposure on behaviour and the functional neural systems that may underpin these deficits which impact on behaviour and neural systems into adulthood.Cannabis abuse can produce deficits in cognition and has been implicated as a 'late' environmental risk factor in the pathogenesis of the poly-factorial disorder schizophrenia. Evidence suggests an age-related susceptibility to the deleterious effects of cannabis as early onset of use may increase the vulnerability of the brain to the adverse consequences of cannabis abuse. Animal models are crucial for exploration of mechanistic and causative theories, and long-term behavioural consequences of adolescent cannabis abuse in a controlled experimental environment. This thesis evaluates the vulnerability of the adolescent/peripubertal brain to Δ9-tetrahydrocannabinol (THC), the principal psychoactive constituent of cannabis, and explores the potential interplay between this schizophrenia-related 'late' environmental risk factor and an 'early' environmental risk factor (prenatal infection - maternal immune activation (MIA)) on functional neural systems and behaviours relevant to schizophrenia. Cannabinoid CB1 receptor ontogeny (activated in the brain by the receptor ligand THC) within important cognitive substrates, the prefrontal cortex (PFC) and hippocampus, was investigated to delineate a period of neurodevelopmental vulnerability for peripubertal THC treatment. CB1 receptor ligand binding revealed that the PFC and hippocampus follow differential late maturational trajectories throughout the peripubertal period. The 'vulnerability window' for peripubertal THC treatment was defined as post-natal day (PD) 35-56 to encompass the dynamic peripubertal ontogenetic patterns of the CB1 receptor in both these regions. Furthermore, age-related alterations in cerebral metabolism and regional functional connectivity profiles were evident in the hippocampus and important neuromodulatory nuclei including the ventral tegmental area, dorsal raphe, locus coeruleus and the diagonal band of Broca.;Acute THC administration (5mg/kg) produced hypometabolism in the thalamus and an altered functional connectivity profile between thalamic nuclei and the PFC, hippocampus and the nucleus accumbens. THC-induced anomalistic neural activity was evident in key neuromodulatory nuclei and produced perturbed functional connectivity within acetylcholine, noradrenaline, and dopamine neural pathways. Acute THC treatment resulted in alterations in cerebral metabolism in the amygdala and aberrant functional connectivity profiles between amygdaloid nuclei and the hippocampus, PFC and nucleus accumbens. There appeared to be an age-related sensitivity to THC in several thalamic, neuromodulatory and amygdaloid nuclei. Peripubertal low-dose intermittent THC (3.5mg/kg, 3 times a week), mimetic of light, recreational adolescent cannabis use, produced long-term cognitive inflexibility, as measured by the attentional-set shifting task, perturbed cerebral metabolism in the dorsolateral orbital cortex and the nucleus accumbens core and altered functional coupling between both these regions and neural substrates subserving reward-related learning including prefrontal, septal and amygdala subfields. High-dose daily THC (7mg/kg) throughout the peripubertal period, mimetic of heavy daily cannabis abuse, did not precipitate any schizophrenia-related behaviours in adulthood. MIA induced by prenatal exposure to the immune-stimulating agent polyriboinosinic-polyribocytidilic acid (PolyIC) did not produce any schizophrenia-related phenotypes in adulthood. However, prenatal PolyIC exposure produced residual hypermetabolism within discrete components of the prefrontal cortex dorsolateral orbital and cingulate cortices and hypometabolism within the CA3 subfield of the hippocampus. The functional connectivity signatures of all these regions indicated a unified MIA effect of aberrant mesocorticolimbic functional coupling in adulthood. Furthermore, chronic intermittent treatment with low-dose THC during the peripubertal period caused an increase in sensitivity to amphetamine (indicative of aberrant mesolimbic dopamine transmission) in PolyIC-treated offspring compared to PBS-treated offspring, suggestive of a synergistic effect of these two environmental risk factors. In conclusion, the findings presented in this thesis have provided clear evidence of dose-specific detrimental effects of 'adolescent' THC exposure on behaviour and the functional neural systems that may underpin these deficits which impact on behaviour and neural systems into adulthood

Haptics: Science, Technology, Applications

This open access book constitutes the proceedings of the 12th International Conference on Human Haptic Sensing and Touch Enabled Computer Applications, EuroHaptics 2020, held in Leiden, The Netherlands, in September 2020. The 60 papers presented in this volume were carefully reviewed and selected from 111 submissions. The were organized in topical sections on haptic science, haptic technology, and haptic applications. This year's focus is on accessibility

Large space structures and systems in the space station era: A bibliography with indexes (supplement 03)

Bibliographies and abstracts are listed for 1221 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1991 and June 30, 1991. Topics covered include large space structures and systems, space stations, extravehicular activity, thermal environments and control, tethering, spacecraft power supplies, structural concepts and control systems, electronics, advanced materials, propulsion, policies and international cooperation, vibration and dynamic controls, robotics and remote operations, data and communication systems, electric power generation, space commercialization, orbital transfer, and human factors engineering

NASA Tech Briefs, April 2000

Topics covered include: Imaging/Video/Display Technology; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Bio-Medical; Test and Measurement; Mathematics and Information Sciences; Books and Reports