Nonlinear dynamics Research Papers - Academia.edu (original) (raw)

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  • Biomedical Engineering, Caenorhabditis elegans, Nonlinear dynamics, Fluorescence
• • by B. Pandurangan
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  • Nonlinear dynamics, Materials modeling, Computer Program, Particle Size

This paper presents a spike-based model which employs neurons with functionally distinct dendritic compartments for classifying high dimensional binary patterns. The synaptic inputs arriving on each dendritic subunit are nonlinearly... more

This paper presents a spike-based model which employs neurons with functionally distinct dendritic compartments for classifying high dimensional binary patterns. The synaptic inputs arriving on each dendritic subunit are nonlinearly processed before being linearly integrated at the soma, giving the neuron a capacity to perform a large number of input-output mappings. The model utilizes sparse synaptic connectivity; where each synapse takes a binary value. The optimal connection pattern of a neuron is learned by using a simple hardware-friendly, margin enhancing learning algorithm inspired by the mechanism of structural plasticity in biological neurons. The learning algorithm groups correlated synaptic inputs on the same dendritic branch. Since the learning results in modified connection patterns, it can be incorporated into current event-based neuromorphic systems with little overhead. This work also presents a branch-specific spike-based version of this structural plasticity rule. The proposed model is evaluated on benchmark binary classification problems and its performance is compared against that achieved using Support Vector Machine (SVM) and Extreme Learning Machine (ELM) techniques. Our proposed method attains comparable performance while utilizing 10 to 50% less computational resources than the other reported techniques.

• • by Shaista Hussain
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  • Algorithms, Nonlinear dynamics, Multidisciplinary, Animals
• • by Catherine M T Sherwin
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  • Research Design, Nonlinear dynamics, Pharmacokinetics, Software
• • by haydar ankışhan
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  • Applied Mathematics, Computer Science, Algorithms, Biomedical Engineering

In the analysis and prediction of real-world systems, two of the key problems are nonstationarity (often in the form of switching between regimes) and overfitting (particularly serious for noisy processes). This article addresses these... more

In the analysis and prediction of real-world systems, two of the key problems are nonstationarity (often in the form of switching between regimes) and overfitting (particularly serious for noisy processes). This article addresses these problems using gated experts, consisting of a (nonlinear) gating network, and several (also nonlinear) competing experts. Each expert learns to predict the conditional mean, and each expert adapts its width to match the noise level in its regime. The gating network learns to predict the probability of each expert, given the input. This article focuses on the case where the gating network bases its decision on information from the inputs. This can be contrasted to hidden Markov models where the decision is based on the previous state(s) (i.e. on the output of the gating network at the previous time step), as well as to averaging over several predictors. In contrast, gated experts soft-partition the input space, only learning to model their region. This...

• • by morgan mangeas
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  • Cognitive Science, Time Series, Nonlinear dynamics, Computers
• • by Victor Klemas
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  • Remote Sensing, Nonlinear dynamics, Multidisciplinary, Tides

In this paper, we numerically investigate the hyperchaotic behaviors in the fractional-order Chen hyperchaotic systems. By utilizing the fractional calculus techniques, we find that hyperchaos exists in the fractional-order Chen... more

In this paper, we numerically investigate the hyperchaotic behaviors in the fractional-order Chen hyperchaotic systems. By utilizing the fractional calculus techniques, we find that hyperchaos exists in the fractional-order Chen hyperchaotic system with the order less than 4. We found that the lowest order for hyperchaos to have in this system is 3.72. Our results are validated by the existence of two positive Lyapunov exponents. The generalized projective synchronization method is also presented for synchronizing the fractional-order Chen hyperchaotic systems. The present technique is based on the Laplace transform theory. This simple and theoretically rigorous synchronization approach enables synchronization of fractional-order hyperchaotic systems to be achieved and does not require the computation of the conditional Lyapunov exponents. Numerical simulations are performed to verify the effectiveness of the proposed synchronization scheme.

• • by Xiangjun Wu
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  • Engineering, Nonlinear dynamics, Numerical Simulation, Mathematical Sciences
• • by Rassul Karabalin
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  • Engineering, Algorithms, Nonlinear dynamics, Computer Simulation

The precise neural mechanisms underlying transitions between consciousness and anesthetic-induced unconsciousness remain unclear. Here, we studied intracortical neuronal dynamics leading to propofol-induced unconsciousness by recording... more

The precise neural mechanisms underlying transitions between consciousness and anesthetic-induced unconsciousness remain unclear. Here, we studied intracortical neuronal dynamics leading to propofol-induced unconsciousness by recording single-neuron activity and local field potentials directly in the functionally interconnecting somatosensory (S1) and frontal ventral premotor (PMv) network during a gradual behavioral transition from full alertness to loss of consciousness (LOC) and on through a deeper anesthetic level. Macaque monkeys were trained for a behavioral task designed to determine the trial-by-trial alertness and neuronal response to tactile and auditory stimulation. We show that disruption of coherent beta oscillations between S1 and PMv preceded, but did not coincide with, the LOC. LOC appeared to correspond to pronounced but brief gamma-/high-beta-band oscillations (lasting ∼3 min) in PMv, followed by a gamma peak in S1. We also demonstrate that the slow oscillations ap...

• • by Omar Essam Ahmed
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  • Neuroscience, Nonlinear dynamics, Electroencephalography, Brain Mapping
• • by Robert Sachdev
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  • Cognitive Science, Nonlinear dynamics, Transcription Factors, Brain Mapping
• • by Mofeed Rashid
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  • Engineering, Nonlinear dynamics, Mathematical Sciences, System Modeling and Simulation
• • by Nabil Maghrebi
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  • Nonlinear dynamics, Stock Market, Empirical evidence, Indexation

A randomization method is developed for the calculation of covariation between multiple variables that are linked nonlinearly to a dependent variable. Covariation is a phenomenon often invoked in the study of movement coordination to... more

A randomization method is developed for the calculation of covariation between multiple variables that are linked nonlinearly to a dependent variable. Covariation is a phenomenon often invoked in the study of movement coordination to capture the fact that in coordinated movement the outcome shows greater than expected consistency from the variability in the component processes. However, in most cases, the problem is that more than two variables covary in a nonlinear fashion, which makes quantification with the bivariate linear covariation and correlation coefficient inapplicable. This paper presents a generalization of the calculation of linear bivariate covariance using a variant of a randomization method that is based on the comparison between the empirically measured variability in the outcome and a covariation-free variability. The latter can be estimated by permuting data sets. A generalized correlation coefficient is derived, and it is shown how errors of estimation can be qua...

• • by Dagmar Sternad
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  • Cognitive Science, International organizations, Principal Component Analysis, Nonlinear dynamics
• • by Cynn Thu
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  • Cognitive Science, Psychophysics, Perception, Behavior
• • by Valeri Beck and +2
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  • Nonlinear dynamics, Biophysical Chemistry, Ion Channels, Molecular Mechanics
• • by Emilio Freire and +1
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  • Nonlinear dynamics, Control system, Oscillations, Electrical And Electronic Engineering
• • by Valipuram Manoranjan
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  • Environmental Engineering, Civil Engineering, Applied Mathematics, Water resources
• • by Sukumar Devotta
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  • Environmental Engineering, Air Quality, Time Series, Nonlinear dynamics
• • by Jean-Claude Desfontis
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  • Pharmacology, Pharmacy, Nonlinear dynamics, Pharmacology and Clinical pharmacy
• • by Gary Frank
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  • Biomedical Engineering, Nonlinear Elasticity, Nonlinear dynamics, Ultrasound

The expected seismic losses of structures with Rotational Friction Dampers (RFDs) are assessed by the Endurance Time (ET) method considering the optimal frictional moment of the devices. A practical method is proposed to obtain the... more

The expected seismic losses of structures with Rotational Friction Dampers (RFDs) are assessed by the Endurance Time (ET) method considering the optimal frictional moment of the devices. A practical method is proposed to obtain the optimal frictional moment of the dampers in multi-story structures at multiple seismic hazard levels. The ET method is used as the analytical tool in this research due to its ability to reduce the number of required analyses and providing good estimations of structural responses at various hazard levels. In order to investigate the effectiveness of the dampers, the life cycle costs of a weak steel structure equipped with optimal RFDs are compared with a standard structure with optimal RFDs and without RFDs. To this end, a comprehensive performance evaluation is performed on the structures based on FEMA P-58 methodology. The ET method is also used as a tool to assess the structural responses in the framework of this methodology. The probability of collapse, fatalities, and expected damage costs are estimated utilizing a Monte Carlo procedure considering uncertainties. Also, a cost-benefit analysis is performed to determine the payback period of investment for the additional cost of the rotational friction damping systems.

• • by Amir Shirkhani
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  • Civil Engineering, Structural Engineering, Earthquake Engineering, Nonlinear dynamics

We show that relativistic invariance is encoded in the multifractal structure of the Standard Model near the electroweak scale. The approximate scale invariance of this structure accounts for the flavor hierarchy and chiral symmetry... more

We show that relativistic invariance is encoded in the multifractal structure of the Standard Model near the electroweak scale. The approximate scale invariance of this structure accounts for the flavor hierarchy and chiral symmetry breaking in the electroweak sector. Surprisingly, it also accounts for breaking of conformal symmetry in General Relativity and the emergence of a non-vanishing cosmological constant.

• • by Ervin Goldfain
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  • Nonlinear dynamics
• • by richard rand
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  • Design Engineering, Applied Mathematics, Nonlinear dynamics, Behavior Analysis
• • by Max Mignotte
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  • Algorithms, Artificial Intelligence, Image Processing, Multidimensional Scaling
• • by Oskar Burger
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  • Reproduction, Nonlinear dynamics, Life history, Population Dynamics
• • by Marie-Noëlle Fiamma
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  • Algorithms, Nonlinear dynamics, Respiratory Physiology, Humans

Time-frequency distribution methods are being widely used for the analysis of a variety of biomedical signals. Recently, they have been applied also to study otoacoustic emissions (OAE's), the active acoustic response of the... more

Time-frequency distribution methods are being widely used for the analysis of a variety of biomedical signals. Recently, they have been applied also to study otoacoustic emissions (OAE's), the active acoustic response of the hearing end organ. Click-evoked otoacoustic emissions (CEOAE's) are time-varying signals with a clear frequency dispersion along with the time axis. Analysis of CEOAE's is of considerable interest due to their close relation with cochlear mechanisms. In this paper, several basic time-frequency distribution methods are considered and compared on the basis of both simulated signals and real CEOAE's. The particular structure of CEOAE's requires a method with both a satisfactory time and frequency resolution. Results from simulations and real CEOAE's revealed that the wavelet approach is highly suitable for the analysis of such signals. Some examples of the application of the wavelet transform to CEOAE's are provided here. Applications range from the extraction of normative data from adult and neonatal OAE's to the extraction of quantitative parameters for clinical purposes.

• • by Gabriella Tognola
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  • Biomedical Engineering, Nonlinear dynamics, Noise Induced Hearing Loss, Linear models
• • by Takashi Odagaki
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  • Engineering, Physics, Materials Science, Thermodynamics

Mizolastine is a second generation antihistamine agent approved in Europe for the treatment of allergic rhinitis and skin conditions for which Sanofi~Synthélabo is developing a pediatric solution. Our objective was to design the... more

Mizolastine is a second generation antihistamine agent approved in Europe for the treatment of allergic rhinitis and skin conditions for which Sanofi~Synthélabo is developing a pediatric solution. Our objective was to design the population pharmacokinetic (PK) study of mizolastine pediatric solution in children. A bioavailability study of this solution compared to the marketed tablet was performed in 18 young volunteers. These PK data were analyzed by nonlinear regression using a two-compartment open model with zero-order absorption. From the estimated parameters, we designed population PK studies in two groups of children: 6 to 12 years and 2 to 6 years, respectively. To compare several population designs and to derive the optimal ones, we used the determinant of the Fisher information matrix of the population characteristics using a first-order expansion of the model. We have evaluated a “reference” population design with 10 samples (from 0.25 to 36 hr after drug intake) per child...

• • by Catherine DUBRUC
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  • Research Design, Nonlinear dynamics, Humans, Child
• • by Teodor Buchner
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  • Mathematics, Applied Mathematics, Nonlinear dynamics, Chaos Theory
• • by Vasilis Marmarelis
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  • Engineering, Mathematics, Computational Neuroscience, Nonlinear dynamics
• • by Juan Manuel Zamorano Valdivia
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  • Mechanical Engineering, Aerospace Engineering, Nonlinear dynamics, Space

Liquid sloshing is an oscillatory motion of a free liquid surface that occurs inside partially filled containers. This phenomenon generates forces that can have a significant influence on a vehicle's safety and stability. Several studies... more

Liquid sloshing is an oscillatory motion of a free liquid surface that occurs inside partially filled containers. This phenomenon generates forces that can have a significant influence on a vehicle's safety and stability. Several studies report methodologies for predicting the liquid slosh in various containers or to the analysis of vehicle stability based upon simplified and linear models of liquid motion without sufficient consideration of the dynamic interactions between the liquid motion and vehicle stability. This work highlights the various parameters attributed to sloshing and gives a review of some selected investigations considering linear and also nonlinear dynamics.

• • by Maria Aline
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  • Nonlinear dynamics, Fluid Dynamics, Computational Fluid Dynamics (CFD) modelling and simulation, Liquid Sloshing
• • by Ricardo Ocaña-Riola
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  • Algorithms, Statistics, Biomedical Engineering, Data Analysis
• • by Jose Pinto
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  • Mechanical Engineering, Chemical Engineering, Nonlinear dynamics, Modeling

The study of transitions in low dimensional, nonlinear dynamical systems is a complex problem for which there is not yet a simple, global numerical method able to detect chaos–chaos, chaos– periodic bifurcations and symmetry-breaking,... more

The study of transitions in low dimensional, nonlinear dynamical systems is a complex problem for which there is not yet a simple, global numerical method able to detect chaos–chaos, chaos– periodic bifurcations and symmetry-breaking, symmetry-increasing bifurcations. We present here for the first time a general framework focusing on the symmetry concept of time series that at the same time reveals new kinds of recurrence. We propose several numerical tools based on the symmetry concept allowing both the qualification and quantification of different kinds of possible symmetry. By using several examples based on periodic symmetrical time series and on logistic and cubic maps, we show that it is possible with simple numerical tools to detect a large number of bifurcations of chaos–chaos, chaos–periodic, broken symmetry and increased symmetry types.

• • by Jean-Marc Girault
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  • Nonlinear dynamics, Time series analysis

In recent decades, shear walls and tube structures have been the most appropriate structural forms for the construction of high-rise concrete buildings. Thus, recent Reinforced Concrete (RC) tall buildings have more complicated structural... more

In recent decades, shear walls and tube structures have been the most appropriate structural forms for the construction of high-rise concrete buildings. Thus, recent Reinforced Concrete (RC) tall buildings have more complicated structural behaviour than before. Therefore, studying the structural systems and associated behaviour of these types of structures is very important. The main objective of this paper is to study the linear and nonlinear behaviour of one of the tallest RC buildings, a 56-storey structure, located in a high seismic zone in Iran. In this tower, shear wall systems with irregular openings are utilized under both gravity and lateral loads and may result in some especial issues in the behaviour of structural elements such as shear walls and coupling beams. The analytical methodologies and the results obtained in the evaluation of life-safety and collapse prevention of the building are also discussed. The weak zones of the structure based on the results are introduced, and a detailed discussion of some important structural aspects of the high-rise shear wall system with consideration of the concrete time dependency and constructional sequence effects is also included. Copyright © 2010 John Wiley & Sons, Ltd.

• • by siamak epackachi
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  • Civil Engineering, Nonlinear dynamics, Structural Design, Reinforced concrete
• • by Wlodzimierz Klonowski
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  • Physiotherapy, Nonlinear dynamics, Fractals, Magnetic field
• • by Zvi Shiller
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  • Optimal Control, Nonlinear dynamics, Computer Aided Design, Productivity
• • by Meng-Chuan Lai
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  • Cognitive Science, Nonlinear dynamics, Magnetic Resonance Imaging, Adolescent
• • by Moha Houssni
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  • Engineering, Nonlinear dynamics, Mathematical Sciences, Stability Analysis
• • by Carlo Laing
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  • Applied Mathematics, Algorithms, Nonlinear dynamics, Coupled Oscillator
• • by Rudolf Stollberger
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  • Algorithms, Biomedical Engineering, Nonlinear dynamics, Magnetic Resonance Imaging

Design a nonlinear controller for second order nonlinear uncertain dynamical systems (e.g., Internal Combustion Engine) is one of the most important challenging works. This paper focuses on the design of a robust backstepping adaptive... more

Design a nonlinear controller for second order nonlinear uncertain dynamical systems (e.g., Internal Combustion Engine) is one of the most important challenging works. This paper focuses on the design of a robust backstepping adaptive feedback linearization controller (FLC) for internal combustion (IC) engine in presence of uncertainties. In order to provide high performance nonlinear methodology, feedback linearization controller is selected. Pure feedback linearization controller can be used to control of partly unknown nonlinear dynamic parameters of IC engine. In order to solve the uncertain nonlinear dynamic parameters, implement easily and avoid mathematical model base controller, Mamdani’s performance/error-based fuzzy logic methodology with two inputs and one output and 49 rules is applied to pure feedback linearization controller. The results demonstrate that the error-based fuzzy feedback linearization controller is a model-free controllers which works well in certain and partly uncertain system. Pure feedback linearization controller and error-based feedback linearization like controller with have difficulty in handling unstructured model uncertainties. To solve this problem applied backstepping-based tuning method to error-based fuzzy feedback linearization controller for adjusting the feedback linearization controller gain ( ). This controller has acceptable performance in presence of uncertainty (e.g., overshoot=1%, rise time=0.48 second, steady state error = 1.3e-9 and RMS error=1.8e-11).

• • by FARZIN PILTAN and +1
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  • Electrical Engineering, Robotics, Control Systems Engineering, Artificial Intelligence

Interest in shape memory alloys (SMA) applications has increased dramatically in recent years. The primary problem in studying systems endowed with SMA devices involves quantifying their mechanical behavior. A most promising tool for this... more

Interest in shape memory alloys (SMA) applications has increased dramatically in recent years. The primary problem in studying systems endowed with SMA devices involves quantifying their mechanical behavior. A most promising tool for this task is the Preisach model, which, due to its abstract nature, is extremely versatile for capturing various hysteretic phenomena present in SMA. In this paper a procedure to calibrate the Preisach model to fit available experimental data is employed first. Then the random responses of SMA systems are investigated by focusing on the numerical implementation of the Preisach model. A version of the stochastic averaging technique is used for this purpose. The probability density function of the amplitude and the power spectral density of the response are determined. Also, the probability density function of the response process is estimated. The analytical results are found in good agreement with those derived by a pertinent Monte Carlo study. Obviously, the methodology described herein can be applied for the study of other hysteretic systems, such as mechanical joints, provided that adequate calibration of the Preisach model has been performed a priori.

• • by Pierfrancesco Cacciola
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  • Engineering, Nonlinear dynamics, Mathematical Sciences
• • by Arindam Basu
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  • Biomedical Engineering, Nonlinear dynamics, Low Power, Nonlinear Model
• • by Octavian Bass
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  • Computer Science, Nonlinear dynamics, Cryptography, Case Study

In this paper, we study the stability problem of nonlinear dynamical control systems. We consider continuous-time dynamical systems whose nominal part is stable and whose perturbed part (uncertainties) is norm-bounded by a positive... more

In this paper, we study the stability problem of nonlinear dynamical control systems. We consider continuous-time dynamical systems whose nominal part is stable and whose perturbed part (uncertainties) is norm-bounded by a positive function. Under some conditions on the perturbation, by using Lyapunov techniques, we show that the system can be uniformly asymptotically stable by a continuous controller.

• • by Mohamed Hammami
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  • Mathematics, Applied Mathematics, Dynamical Systems, Nonlinear dynamics
• • by Tony Fitzgerald
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  • Statistics, Nonlinear dynamics, Adolescent, Medicine