A new robust controller is proposed to regulate both flexural vibrations and rigid body motion of a hydraulically driven flexible arm. The controller combines backstepping control and sliding mode to arrive at a contr...A new robust controller is proposed to regulate both flexural vibrations and rigid body motion of a hydraulically driven flexible arm. The controller combines backstepping control and sliding mode to arrive at a controller capable of dealing with a nonlinear system with uncertainties. The sliding mode technique is used to achieve an asymptotic joint angle and vibration regulation in the presence of payload uncertainty by providing a virtual torque input at the joint while the backstepping technique is used to regulate the spool position of a hydraulic valve to provide the required torque. It is shown that there is no chatter in the hydraulic valve, which results in smoother operation of the system.展开更多
By using Impulsive Maximum Principal and three stage optimization method,this paper discusses optimization problems for linear impulsive switched systems with hybridcontrols, which includes continuous control and impu...By using Impulsive Maximum Principal and three stage optimization method,this paper discusses optimization problems for linear impulsive switched systems with hybridcontrols, which includes continuous control and impulsive control. The linear quadratic optimizationproblems without constraints such as optimal hybrid control, optimal stability and optimalswitching instants are addressed in detail. These results are applicable to optimal control problemsin economics,mechanics, and management.展开更多
The classical deterministic dynamics of a Brownian particle with a time-dependent periodic perturbation in a spatially periodic potential is investigated. We have constructed a perturbed chaotic solution near the hete...The classical deterministic dynamics of a Brownian particle with a time-dependent periodic perturbation in a spatially periodic potential is investigated. We have constructed a perturbed chaotic solution near the heteroclinic orbit of the nonlinear dynamics system by using the Constant-Variation method. Theoretical analysis and numerical result show that the motion of the Brownian particle is a kind of chaotic motion. The corresponding chaotic region in parameter space is obtained analytically and numerically.展开更多
We present a stability and error analysis of an embedded-hybridized discontinuous Galerkin(EDG-HDG)finite element method for coupled Stokes-Darcy flow and transport.The flow problem,governed by the Stokes-Darcy equati...We present a stability and error analysis of an embedded-hybridized discontinuous Galerkin(EDG-HDG)finite element method for coupled Stokes-Darcy flow and transport.The flow problem,governed by the Stokes-Darcy equations,is discretized by a recently introduced exactly mass conserving EDG-HDG method while an embedded discontinuous Galerkin(EDG)method is used to discretize the transport equation.We show that the coupled flow and transport discretization are compatible and stable.Furthermore,we show the existence and uniqueness of the semi-discrete transport problem and develop optimal a priori error estimates.We provide numerical examples illustrating the theoretical results.In particu-lar,we compare the compatible EDG-HDG discretization to a discretization of the coupled Stokes-Darcy and transport problem that is not compatible.We demonstrate that where the incompatible discretization may result in spurious oscillations in the solution to the trans-port problem,the compatible discretization is free of oscillations.An additional numerical example with realistic parameters is also presented.展开更多
In this paper, a novel biometric identification system is presented toidentify a person''s identity by his/her palmprint. In contrast to existing palmprint systems forcriminal applications, the proposed system...In this paper, a novel biometric identification system is presented toidentify a person''s identity by his/her palmprint. In contrast to existing palmprint systems forcriminal applications, the proposed system targets at the civil applications, which requireidentifying a person in a large database with high accuracy in real-time. The system is constitutedby four major components: User Interface Module, Acquisition Module, Recognition Module and ExternalModule. More than 7,000 palmprint images have been collected to test the performance of the system.The system can identify 400 palms with a low false acceptance rate, 0.02%, and a high genuineacceptance rate, 98.83%. For verification, the system can operate at a false acceptance rate, 0.017%and a false rejection rate, 0.86%. The execution time for the whole process including imagecollection, preprocessing, feature extraction and matching is less than 1 second.展开更多
A graph property is a set of graphs such that if the set contains some graph G then it also contains each isomorphic copy of G (with the same vertex set). A graph property P on n ventices is said to be elusive, if eve...A graph property is a set of graphs such that if the set contains some graph G then it also contains each isomorphic copy of G (with the same vertex set). A graph property P on n ventices is said to be elusive, if every decision tree algorithm recognizing P must examine all n(n - 1)/2 pairs of ventices in the worst case. Karp conjectured that every nontrivial monotone graph property is elusive. In this paper, this conjecture is proved for some cases. Especially,it is shown that if the abstract simplicial complex of a nontrivial monotone graph property P has dimension not exceeding 5, then P is elusive.展开更多
This note settles the complexity of the single genotype resolution problemshowing it is NP-complete. This solves an open problem raised by P. Bonizzoni, G.D. Vedova, R.Dondi, and J. Li. The same proof also gives an al...This note settles the complexity of the single genotype resolution problemshowing it is NP-complete. This solves an open problem raised by P. Bonizzoni, G.D. Vedova, R.Dondi, and J. Li. The same proof also gives an alternative and simpler reduction of the NP-hardnessof Maximum Resolution problem.展开更多
This paper investigates periodic boundary value problem for first order nonlinear impulsive integro-differelltial equations of mixed type in a Banach space. By establishing a comparison result, criteria on the existen...This paper investigates periodic boundary value problem for first order nonlinear impulsive integro-differelltial equations of mixed type in a Banach space. By establishing a comparison result, criteria on the existence of maximal and minimal solutions are obtained.展开更多
文摘A new robust controller is proposed to regulate both flexural vibrations and rigid body motion of a hydraulically driven flexible arm. The controller combines backstepping control and sliding mode to arrive at a controller capable of dealing with a nonlinear system with uncertainties. The sliding mode technique is used to achieve an asymptotic joint angle and vibration regulation in the presence of payload uncertainty by providing a virtual torque input at the joint while the backstepping technique is used to regulate the spool position of a hydraulic valve to provide the required torque. It is shown that there is no chatter in the hydraulic valve, which results in smoother operation of the system.
文摘By using Impulsive Maximum Principal and three stage optimization method,this paper discusses optimization problems for linear impulsive switched systems with hybridcontrols, which includes continuous control and impulsive control. The linear quadratic optimizationproblems without constraints such as optimal hybrid control, optimal stability and optimalswitching instants are addressed in detail. These results are applicable to optimal control problemsin economics,mechanics, and management.
文摘The classical deterministic dynamics of a Brownian particle with a time-dependent periodic perturbation in a spatially periodic potential is investigated. We have constructed a perturbed chaotic solution near the heteroclinic orbit of the nonlinear dynamics system by using the Constant-Variation method. Theoretical analysis and numerical result show that the motion of the Brownian particle is a kind of chaotic motion. The corresponding chaotic region in parameter space is obtained analytically and numerically.
基金the Natural Sciences and Engineering Research Council of Canada through the Discovery Grant program(RGPIN-05606-2015).
文摘We present a stability and error analysis of an embedded-hybridized discontinuous Galerkin(EDG-HDG)finite element method for coupled Stokes-Darcy flow and transport.The flow problem,governed by the Stokes-Darcy equations,is discretized by a recently introduced exactly mass conserving EDG-HDG method while an embedded discontinuous Galerkin(EDG)method is used to discretize the transport equation.We show that the coupled flow and transport discretization are compatible and stable.Furthermore,we show the existence and uniqueness of the semi-discrete transport problem and develop optimal a priori error estimates.We provide numerical examples illustrating the theoretical results.In particu-lar,we compare the compatible EDG-HDG discretization to a discretization of the coupled Stokes-Darcy and transport problem that is not compatible.We demonstrate that where the incompatible discretization may result in spurious oscillations in the solution to the trans-port problem,the compatible discretization is free of oscillations.An additional numerical example with realistic parameters is also presented.
文摘In this paper, a novel biometric identification system is presented toidentify a person''s identity by his/her palmprint. In contrast to existing palmprint systems forcriminal applications, the proposed system targets at the civil applications, which requireidentifying a person in a large database with high accuracy in real-time. The system is constitutedby four major components: User Interface Module, Acquisition Module, Recognition Module and ExternalModule. More than 7,000 palmprint images have been collected to test the performance of the system.The system can identify 400 palms with a low false acceptance rate, 0.02%, and a high genuineacceptance rate, 98.83%. For verification, the system can operate at a false acceptance rate, 0.017%and a false rejection rate, 0.86%. The execution time for the whole process including imagecollection, preprocessing, feature extraction and matching is less than 1 second.
文摘A graph property is a set of graphs such that if the set contains some graph G then it also contains each isomorphic copy of G (with the same vertex set). A graph property P on n ventices is said to be elusive, if every decision tree algorithm recognizing P must examine all n(n - 1)/2 pairs of ventices in the worst case. Karp conjectured that every nontrivial monotone graph property is elusive. In this paper, this conjecture is proved for some cases. Especially,it is shown that if the abstract simplicial complex of a nontrivial monotone graph property P has dimension not exceeding 5, then P is elusive.
文摘This note settles the complexity of the single genotype resolution problemshowing it is NP-complete. This solves an open problem raised by P. Bonizzoni, G.D. Vedova, R.Dondi, and J. Li. The same proof also gives an alternative and simpler reduction of the NP-hardnessof Maximum Resolution problem.
文摘This paper investigates periodic boundary value problem for first order nonlinear impulsive integro-differelltial equations of mixed type in a Banach space. By establishing a comparison result, criteria on the existence of maximal and minimal solutions are obtained.
