We investigate the dynamical origin for the occurrence of asynchronous hyperchaos and chaos via blowout bifurcations in coupled chaotic systems. An asynchronous hyperchaotic or chaotic attractor with a positive or neg...
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We investigate the dynamical origin for the occurrence of asynchronous hyperchaos and chaos via blowout bifurcations in coupled chaotic systems. An asynchronous hyperchaotic or chaotic attractor with a positive or negative second Lyapunov exponent appears through a blowout bifurcation. It is found that the sign of the second Lyapunov exponent of the newly born asynchronous attractor, exhibiting on-off intermittency, is determined through competition between its laminar and bursting components. When the “strength” (i.e., a weighted second Lyapunov exponent) of the bursting component is larger (smaller) than that of the laminar component, an asynchronous hyperchaotic (chaotic) attractor appears.
A neural-network-based iterative controller is presented focusing on the speed control of ultrasonic motors. Suitable ranges of the adaptive learning rates are presented through the theoretical analysis on the propose...
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A neural-network-based iterative controller is presented focusing on the speed control of ultrasonic motors. Suitable ranges of the adaptive learning rates are presented through the theoretical analysis on the proposed model, which could guarantee the fastest convergence of the neural network controller. Numerical results show that the neural-network-based controller is effective for various kinds of reference speeds of ultrasonic motors. Comparisons with the existing method show that the precision of control could be increased using the proposed method. Simulations also show that the proposed scheme is fairly robust against random disturbance to the control variables.
Much of the current research in the design of virtual environments is centred on laboratory prototypes and emphasis is placed on supporting cooperation within the virtual world itself. By way of contrast, this paper p...
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“Team Sweden” is the Swedish national team that entered the Sony legged robot league at the RoboCup2001 competition. The work was distributed over three universities in Sweden. This nationwide character has made the...
ISBN:
(纸本)3540439129
“Team Sweden” is the Swedish national team that entered the Sony legged robot league at the RoboCup2001 competition. The work was distributed over three universities in Sweden. This nationwide character has made the project organization particularly demanding, but has resulted in a rewarding cooperation experience, both scientific and human. The Team identity is as follows: Team Leader: Alessandro Saffiotti (asaffio@***) Team Members: include the authors, plus: R. Johansson (?rebro); P. Davidsson, D. Erman, and J. Kronqvist (Blekinge); J. Carstensen, P. Eklund, P. Larsson, and K. Prorok (Ume?). Sponsors: Swedish KK foundation, Qualisys AB, ?rebro University, Ume? University, and the Blekinge Institute of technology. Team home page: http://***/Living/RoboCup/.
We introduce the concept of variable-consistency monotonic decision tree induced from preference-ordered data concerning a multicriteria sorting (classification) problem. Given the data in form of an information table...
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This paper shows that Statecharts, a high-level specification technique, can be used to represent performance models. This is a powerful technique and is based on state-transition diagrams added with concepts of hiera...
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This paper shows that Statecharts, a high-level specification technique, can be used to represent performance models. This is a powerful technique and is based on state-transition diagrams added with concepts of hierarchy and orthogonality to represent a system behavior. It is shown that Statecharts may conveniently be used to represent models with richness and clarity. Using an analytical approach the technique to determine performance measurements is provided. Three examples are presented and the results show Statecharts’ potential for representing systems for performance evaluation. International Federation of Operational Research Societies 2002.
Neural networks are employed to predict the amount and location of propulsion system rotor unbalance. Vibration data used to train and test inverse system models are generated via a high-order structural dynamic finit...
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Neural networks are employed to predict the amount and location of propulsion system rotor unbalance. Vibration data used to train and test inverse system models are generated via a high-order structural dynamic finite element model. Several neural network methods, including feed forward neural network using back propagation, node-decoupled Kalman filter (NDEKF) and support vector machines (SVMs) are investigated. Training results and performance among the various methods are compared. Original applications to nonlinear structural models and damaged structure models are shown.
We propose the use of surface subdivision as adaptive and higher-order boundary elements for solving a Helmholtz partial differential equation to calculate accurate acoustic scattering on arbitrary manifolds. Such aco...
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We propose the use of surface subdivision as adaptive and higher-order boundary elements for solving a Helmholtz partial differential equation to calculate accurate acoustic scattering on arbitrary manifolds. Such acoustic transfer functions prove useful for designing and tuning hearing aid devices for hearing impaired individuals. The number of unknowns of the discretized linear system is the same as that in a linear element approach. Our results show that the accuracy of the subdivision approach is much better than that of the linear element approach.
A new method for the calculation of the magnetic field of beam guiding elements is presented. The method relates the calculation to measurement data of the magnetic field in a direct way. It can be applied to single b...
A new method for the calculation of the magnetic field of beam guiding elements is presented. The method relates the calculation to measurement data of the magnetic field in a direct way. It can be applied to single beam guiding elements as well as to clusters of elements. The presented description of the magnetic field differs from the classical approach in that it does not rely on power series approximations. It is also both divergence free and curl free, and takes fringe field effects up to any desired order into account. In the field description, pseudodifferential operators described by Bessel functions are used to obtain the various multipole contributions. Magnetic field data on a two-dimensional surface, e.g., a cylindrical surface or median plane, serve as input for the calculation of the three-dimensional magnetic field. A boundary element method is presented to fit the fields to a discrete set of field data, obtained, for instance, from field measurements, on the two-dimensional surface. Relative errors in the field approximation do not exceed the maximal relative errors in the input data. Methods for incorporating the obtained field in both analytical and numerical computation of transfer functions are outlined. Applications include easy calculation of the transfer functions of clusters of beam guiding elements and of generalized field gradients for any multipole contribution up to any order.
A = (a[sub ij]) ∈ R[sup n×n] is termed bisymmetric matrix if a[sub ij] = a[sub ji] = a[sup n ? j + 1, n ? i + 1], i, j = 1, 2 ··· n. We denote the set of all n x n bisymmetric matrices by BSR[sup ...
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A = (a[sub ij]) ∈ R[sup n×n] is termed bisymmetric matrix if a[sub ij] = a[sub ji] = a[sup n ? j + 1, n ? i + 1], i, j = 1, 2 ··· n. We denote the set of all n x n bisymmetric matrices by BSR[sup n x n]. This paper is mainly concerned with solving the following two problems: Problem I. Given X, B ∈ R[sup n×m], find A ∈ P[sub n] such that AX = B, where P[sub n] = {A ∈ BSR[sup n×n]| x[sup T] Ax ≥ 0, ?x ∈ R[sup n]}. Problem II. Given A[sup *] ∈ R[sup n×n], find ? ∈ S[sub E] such that ||A[sup *] - ?||[sub F] = ... ||A[sup *] - A||[sub F] where || · ||[sub F] is Frobenius norm, and S[sub E] denotes the solution set of problem I. The necessary and sufficient conditions for the solvability of problem I have been studied. The general form of S[sub E] has been given. For problem II the expression of the solution has been provided. [ABSTRACT FROM AUTHOR]
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