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172 results on '"Wu, Jian-Da"'

2. Properties of Geometric Potential in the Invariant Adiabatic Theory

Author

Zhao, Mei-sheng, Wu, Jian-da, Chen, Jian-lan, and Zhang, Yong-de

Subjects
Quantum Physics
Abstract

We concentrate on the geometric potential in the invariant perturbation theory of quantum adiabatic process which is presented in our recent papers. It is found out to be related to the geodesic curvature of the spherical curve in 2-dimension quantum systems. We also show that the geometric potential may affect adiabatic approximation remarkably., Comment: 4 pages, 6 figures

Published
2007

3. Invariant Perturbation Theory of Adiabatic Process

Author

Chen, Jian-Lan, Zhao, Mei-sheng, Wu, Jian-da, and Zhang, Yong-de

Subjects
Quantum Physics
Abstract

In this paper we present an invariant perturbation theory to adiabatic process according to the concepts of adiabatic orbits, adiabatic evolution orbit and U(1)-invariant adiabatic orbit. The probabilities of keeping the adiabatic orbit in the first-order and the second-order approximation are calculated, respectively. We also give a convenient sufficient condition., Comment: 4 pages, no figures

Published
2007

4. Adiabatic Approximation Condition

Author

Wu, Jian-da, Zhao, Mei-sheng, Chen, Jian-lan, and Zhang, Yong-de

Subjects
Quantum Physics
Abstract

In this paper, we present an invariant perturbation theory of the adiabatic process based on the concepts of U(1)-invariant adiabatic orbit and U(1)-invariant adiabatic expansion. As its application, we propose and discuss new adiabatic approximation conditions., Comment: 4 pages, no figures

Published
2007

5. The Generation and Exchange of Entanglement via Zeeman Effect

Author

Wu, Jian-da, Chen, Jian-lan, and Zhang, Yong-de

Subjects
Quantum Physics
Abstract

In this paper we show a new way to generate entanglement via two identical three-level atoms splitting in the magnetic field interacting with the cavity field. By the system we investigate, We can acquire the EPR state, multi-dimensional entangled states etc. which are more stable than usual realization by high-energy-level Rydberg atoms and we can realize the local exchange operator too. We also achieve the goal of maintaining long- time entanglement between atoms. At last, by using the procedure of local exchange, we put forward an experimental scheme for quantum feedback., Comment: 9 pages, 1 figure

Published
2006

46. Acoustic Emission Signal Classification Using Feature Analysis and Deep Learning Neural Network.

Author

Wu, Jian-Da, Wong, Yu-Han, Luo, Wen-Jun, and Yao, Kai-Chao

Subjects
*SIGNAL classification, *ACOUSTIC emission, *ARTIFICIAL intelligence, *WAVELET transforms, *DEEP learning, *FEATURE extraction, *DATA analysis
Abstract

With the development of artificial intelligence in recent years, deep learning has been widely used in mechanical system signal classification but the impact of different feature extractions on the efficiency and effectiveness of deep learning neural networks is more important. In this study, a vehicle classification based on engine acoustic emission signal in the time domain, the frequency domain and the wavelet transform domain for deep learning network techniques is presented and compared. In signal classification, different feature extractions will show in different decomposition levels and can be used to recognize the various acoustic conditions. In the experimental work, as engines from 10 different ground vehicles operate, the measured sound signal is converted into a digital signal, and the established data set is classified and identified by the deep learning method. The number of samples, identification rate and identification time in the various signal domains are compared and discussed in this study. Finally, the experimental results and data analysis show that by using the wavelet signal and the deep learning method, excellent identification time and identification rate can be achieved, compared with traditional time and frequency domain signals. [ABSTRACT FROM AUTHOR]

Published
2021
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47. From the transverse field Ising chain to the quantum E8 integrable model

Author

Wang Xiao, Wu Jian-Da, and Yang Jia-Hao

Subjects
Physics, Ising chain, Integrable system, Transverse field, General Physics and Astronomy, Quantum, Mathematical physics
Abstract

This review reports a series of theoretical and experimental progress on researches of the transverse field Ising chain (TFIC) and the quantum E8 integrable model. For the TFIC, on one hand, a unique exotic quantum critical behavior of Grüneisen ratio (a ratio from magnetic or thermal expansion coefficient to specific heat) is theoretically established; on the other hand microscopic models can accommodate the TFIC universality class are substantially expanded. These progresses successfully promote a series of experiments collaborations to first-time realize the TFIC universality class in quasi one-dimensional anti-ferromagnetic material BaCo2V2O8 and SrCo2V2O8. For the quantum E8 integrable model, the low temperature local dynamics and the dynamical structure factor with zero transfer momentum of this system are analytically determined, where a cascade of edge singularities with power-law divergences are obtained in the continuum region of the dynamical structure factor. After combining with detailed quantum critical scaling behaviors analysis and large scale iTEBD calculation, it successfully facilitates a series of experiments, including THz spectrum measurements, inelastic neutron scattering and NMR experiments, to realize the quantum E8 integrable model in BaCo2V2O8 for the first time. The experimental realization of the quantum E8 integrable model substantially extends the frontiers of studying quantum integrable models in real materials. The series of progress and developments on the TFIC and the quantum E8 integrable model lay down a concrete ground to go beyond quantum integrability, and can inspire studies in condensed matter systems, cold atom systems, statistical field theory and conformal field theory.

Published
2021

50. Experimental investigation of active vibration control for gear set shaft

Author

Wu, Jian-Da and Lin, Jia-Hong

Subjects
Gearing -- Analysis, Automobile industry
Abstract

Byline: Jian-Da Wu, Jia-Hong Lin In this study, three different active vibration control (AVC) algorithms are implemented and compared in the experimental investigation of gear set shaft vibration control. Apart from feedforward and feedback control system, a hybrid controller is proposed, which is a combination of the adaptive control with filtered-x least mean squares (FXLMS) algorithm and feedback structure with robust synthesis theory for obtaining the fast convergence and good robust performance. The control plant configuration is identified by the frequency domain technique and implemented by using a digital signal processor (DSP). Experiments are carried out to evaluate the vibration attenuation performance of three control systems at gear set shaft. The results of the experiment indicate that the hybrid technique is effective in reducing the vibration and yield the best performance in experimental investigation. The experimental comparison and analysis of the proposed controllers are also described in this paper.

Published
2005

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