We numerically study the dynamics of meandering spiral waves in the excitable system subjected to a feedback signal coming from two measuring points located on a straight line together with the initial spiral core. Th...We numerically study the dynamics of meandering spiral waves in the excitable system subjected to a feedback signal coming from two measuring points located on a straight line together with the initial spiral core. The core location and size radius of the final attractors are computed, and they change with the position of the moving measuring point in a unique way. By the Fourier Spectral analysis, we find the frequency-locked behaviors different from the driving scheme of the external periodic force. It when the moving measuring point approaches closely is also found that the meandering spiral wave can be eliminated the boundary and its feedback gain is large enough. This offers an effective and convenient method for eliminating meandering spiral waves.展开更多
Recently,Quality of Experience(QoE)has been introduced as a subjective measure of a user’s experience of communication services.QoE was expected to take the place of traditional Quality of Service(QoS)measure in that...Recently,Quality of Experience(QoE)has been introduced as a subjective measure of a user’s experience of communication services.QoE was expected to take the place of traditional Quality of Service(QoS)measure in that QoE may express a direct and accurate user experience.In this paper,we propose a QoE management scheme which is based on a user’s simple feedback.We explain the proposed QoE management steps and the dominant reason extraction algorithm to determine the quality-falling instance.We also present a QoE prediction method that will provide an optimal quality management scheme in communication services.Experiments on multimedia streaming service prove the efficiency of the dominant factor extraction algorithm,and the experiment using the QoE prediction method present a very high accuracy.The QoE management scheme proposed in this paper can be generally adapted to any communication services,to increase the efficiency and effectiveness of quality management systems.展开更多
We consider the system consisting of two qubits collectively damped, with the output being unit-efficiency measured and subsequently fed back to control the system state. Our primary goal in this paper is （i） to sol...We consider the system consisting of two qubits collectively damped, with the output being unit-efficiency measured and subsequently fed back to control the system state. Our primary goal in this paper is （i） to solve the feedback-modified master equation, （ii） to demonstrate the ability of feedback control based on the solutions, and （iii） to pick out different steady states by choosing different driving strengths and feedback strengths to counteract the effects of both damping and the measurement back-action on the system. We further investigate some properties of the equilibrium steady state, its distribution probability and entanglement vs. the driving and feedback amplitudes. We find that in our feedback model feedback plays a negative role in producing entanglement.展开更多
A control problem of a chain of integrator system with measurement noise on feedback sensor is considered. We propose a gain-scaling controller for compensating measurement noise of feedback sensor. Because control sy...A control problem of a chain of integrator system with measurement noise on feedback sensor is considered. We propose a gain-scaling controller for compensating measurement noise of feedback sensor. Because control systems operate via feedback sensor＇s signal, the measurement noise in sensor＇ signal results in performance degradation or even system failure. Therefore, control systems often demand on compensating measurement noise. Our controller is equipped with a compensator and gain-scaling factor in order to reduce the effect of measurement noise on feedback sensor.展开更多
Optical-phase-retardation elements are widely used in many fields.Accurate measurement of their phase retardation is crucial to the practical effect of the element's processing and application.The development and ...Optical-phase-retardation elements are widely used in many fields.Accurate measurement of their phase retardation is crucial to the practical effect of the element's processing and application.The development and present situation of the methods for optical phase retardation measurement are reviewed,with the wave plate,the most typical phase-retardation element,as an example.The latest research progress in this field is introduced;the principles and characteristics of individual measurement method are summarized and discussed.Three new methods based on laser frequency splitting or laser feedback are presented in detail,in which the laser is not only regarded as a light source but also plays a role of sensor.Moreover,no standard wave plates are needed and arbitrary phase retardation can be measured.Traceability,high precision and high repeatability are achieved as well.展开更多
We investigate asymptotical stabilization for a class of chaotic systems by means of quantization measurements of states.The quantizer adopted in this paper takes finite many values.In particular,one zoomer is placed ...We investigate asymptotical stabilization for a class of chaotic systems by means of quantization measurements of states.The quantizer adopted in this paper takes finite many values.In particular,one zoomer is placed at the input terminal of the quantizer,and another zoomer is located at the output terminal of the quantizer.The zoomers possess a common adjustable time-varying parameter.By using the adaptive laws for the time-varying parameter and estimating boundary error of values of quantization,the stabilization feedback controller with the quantized state measurements is proposed for a class of chaotic systems.Finally,some numerical examples are given to demonstrate the validity of the proposed methods.展开更多
We study the performance of space division multiple access （SDMA） under a non-ideal engineering situation. When the SDMA channel is of high inter-layer correlation and the condition number is large, the multiple use...We study the performance of space division multiple access （SDMA） under a non-ideal engineering situation. When the SDMA channel is of high inter-layer correlation and the condition number is large, the multiple user multiple input and multiple output user equipment （MUMIMOUE） grouping should be optimized, and in some cases further dimension-reduction should be applied. As the channel measuring is always non-ideal, we use two methods, feedback mode and non-feedback mode, in terms of performance and overhead. It is proposed that the non-feedback mode is preferable even for some non-reciprocal channels. Prin- ciple analysis and test results are given.展开更多
We consider an open quantum system subjected to a noise channel under measurement-based feedback control and two prototypical classes of decoherence channels are considered： phase damping and generalized amplitude da...We consider an open quantum system subjected to a noise channel under measurement-based feedback control and two prototypical classes of decoherence channels are considered： phase damping and generalized amplitude damping. Based on quantum trajectory theory, we obtain an extended master equation for the dynamics of the reduced system in the presence of feedback control. For a qubit system we analytically solve this master equation and obtain the solution of the state vector dynamics. Then we propose an effective feedback control scheme for preparing an arbitrary quantum pure state. We also study how to protect two nonorthogonai states effectively, and find that projective measurement with unbiazed basis is not optimal for this task, while weak measurement with biased basis could realize the best protection of two nonorthogonal states. Furthermore, the inefficiencies in the feedback process are also discussed展开更多
基金Supported by the National Natural Science Foundation of China under Grant No. 11005030Science Foundations of Hebei Education Department under Grant No. 2009135+1 种基金Science Foundations of Inner Mongolia Education Department under Grant No. NJ09178Science Foundation of Hebei Normal University
文摘We numerically study the dynamics of meandering spiral waves in the excitable system subjected to a feedback signal coming from two measuring points located on a straight line together with the initial spiral core. The core location and size radius of the final attractors are computed, and they change with the position of the moving measuring point in a unique way. By the Fourier Spectral analysis, we find the frequency-locked behaviors different from the driving scheme of the external periodic force. It when the moving measuring point approaches closely is also found that the meandering spiral wave can be eliminated the boundary and its feedback gain is large enough. This offers an effective and convenient method for eliminating meandering spiral waves.
基金supported by the Ministry of Knowledge Economy (MKE), Korea, under the Convergence Information Technology Research Center (CITRC) support program, under Grant No. NIPA-2012-H0401-12-1002supervised by the National IT Industry Promotion Agency (NIPA)
文摘Recently,Quality of Experience(QoE)has been introduced as a subjective measure of a user’s experience of communication services.QoE was expected to take the place of traditional Quality of Service(QoS)measure in that QoE may express a direct and accurate user experience.In this paper,we propose a QoE management scheme which is based on a user’s simple feedback.We explain the proposed QoE management steps and the dominant reason extraction algorithm to determine the quality-falling instance.We also present a QoE prediction method that will provide an optimal quality management scheme in communication services.Experiments on multimedia streaming service prove the efficiency of the dominant factor extraction algorithm,and the experiment using the QoE prediction method present a very high accuracy.The QoE management scheme proposed in this paper can be generally adapted to any communication services,to increase the efficiency and effectiveness of quality management systems.
基金Supported by the National Natural Science Foundation of China under Grant Nos.10775100,10974137 and 10805034the Fund of Theoretical Nuclear Center of HIRFL of Chinathe Scientific Research Foundation of CUIT under Grant No.KYTZ201024
文摘We consider the system consisting of two qubits collectively damped, with the output being unit-efficiency measured and subsequently fed back to control the system state. Our primary goal in this paper is （i） to solve the feedback-modified master equation, （ii） to demonstrate the ability of feedback control based on the solutions, and （iii） to pick out different steady states by choosing different driving strengths and feedback strengths to counteract the effects of both damping and the measurement back-action on the system. We further investigate some properties of the equilibrium steady state, its distribution probability and entanglement vs. the driving and feedback amplitudes. We find that in our feedback model feedback plays a negative role in producing entanglement.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology(2010-0007325)
文摘A control problem of a chain of integrator system with measurement noise on feedback sensor is considered. We propose a gain-scaling controller for compensating measurement noise of feedback sensor. Because control systems operate via feedback sensor＇s signal, the measurement noise in sensor＇ signal results in performance degradation or even system failure. Therefore, control systems often demand on compensating measurement noise. Our controller is equipped with a compensator and gain-scaling factor in order to reduce the effect of measurement noise on feedback sensor.
基金supported by the Key Program of National Natural Science Foundation of China(Grant No.61036016)
文摘Optical-phase-retardation elements are widely used in many fields.Accurate measurement of their phase retardation is crucial to the practical effect of the element's processing and application.The development and present situation of the methods for optical phase retardation measurement are reviewed,with the wave plate,the most typical phase-retardation element,as an example.The latest research progress in this field is introduced;the principles and characteristics of individual measurement method are summarized and discussed.Three new methods based on laser frequency splitting or laser feedback are presented in detail,in which the laser is not only regarded as a light source but also plays a role of sensor.Moreover,no standard wave plates are needed and arbitrary phase retardation can be measured.Traceability,high precision and high repeatability are achieved as well.
基金Supported by the National Science Foundation of China under Grant No.11172017the Guangdong Natural Science Foundation under Grant No.8151009001000061Natural Science Joint Research Program Foundation of Guangdong Province under Grant No.8351009001000002
文摘We investigate asymptotical stabilization for a class of chaotic systems by means of quantization measurements of states.The quantizer adopted in this paper takes finite many values.In particular,one zoomer is placed at the input terminal of the quantizer,and another zoomer is located at the output terminal of the quantizer.The zoomers possess a common adjustable time-varying parameter.By using the adaptive laws for the time-varying parameter and estimating boundary error of values of quantization,the stabilization feedback controller with the quantized state measurements is proposed for a class of chaotic systems.Finally,some numerical examples are given to demonstrate the validity of the proposed methods.
文摘We study the performance of space division multiple access （SDMA） under a non-ideal engineering situation. When the SDMA channel is of high inter-layer correlation and the condition number is large, the multiple user multiple input and multiple output user equipment （MUMIMOUE） grouping should be optimized, and in some cases further dimension-reduction should be applied. As the channel measuring is always non-ideal, we use two methods, feedback mode and non-feedback mode, in terms of performance and overhead. It is proposed that the non-feedback mode is preferable even for some non-reciprocal channels. Prin- ciple analysis and test results are given.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11274043 and 11375025
文摘We consider an open quantum system subjected to a noise channel under measurement-based feedback control and two prototypical classes of decoherence channels are considered： phase damping and generalized amplitude damping. Based on quantum trajectory theory, we obtain an extended master equation for the dynamics of the reduced system in the presence of feedback control. For a qubit system we analytically solve this master equation and obtain the solution of the state vector dynamics. Then we propose an effective feedback control scheme for preparing an arbitrary quantum pure state. We also study how to protect two nonorthogonai states effectively, and find that projective measurement with unbiazed basis is not optimal for this task, while weak measurement with biased basis could realize the best protection of two nonorthogonal states. Furthermore, the inefficiencies in the feedback process are also discussed
