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Quantum-Classical Algorithm for an Instantaneous Spectral Analysis of Signals:A Complement to Fourier Theory 被引量:2
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作者 Mario Mastriani 《Journal of Quantum Information Science》 2018年第2期52-77,共26页
A quantum time-dependent spectrum analysis, or simply, quantum spectral analysis (QSA) is presented in this work, and it’s based on Schr&#246;dinger’s equation. In the classical world, it is named frequency in t... A quantum time-dependent spectrum analysis, or simply, quantum spectral analysis (QSA) is presented in this work, and it’s based on Schr&#246;dinger’s equation. In the classical world, it is named frequency in time (FIT), which is used here as a complement of the traditional frequency-dependent spectral analysis based on Fourier theory. Besides, FIT is a metric which assesses the impact of the flanks of a signal on its frequency spectrum, not taken into account by Fourier theory and lets alone in real time. Even more, and unlike all derived tools from Fourier Theory (i.e., continuous, discrete, fast, short-time, fractional and quantum Fourier Transform, as well as, Gabor) FIT has the following advantages, among others: 1) compact support with excellent energy output treatment, 2) low computational cost, O(N) for signals and O(N2) for images, 3) it does not have phase uncertainties (i.e., indeterminate phase for a magnitude = 0) as in the case of Discrete and Fast Fourier Transform (DFT, FFT, respectively). Finally, we can apply QSA to a quantum signal, that is, to a qubit stream in order to analyze it spectrally. 展开更多
关键词 fourier theory Heisenberg’s Uncertainty Principle Quantum fourier Transform Quantum Information Processing Quantum Signal Processing Schrodinger’s Equation Spectral Analysis
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Mechanism of micro-waviness induced KH_2PO_4 crystal laser damage and the corresponding vibration source 被引量:1
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作者 李明全 陈明君 +4 位作者 安晨辉 周炼 程健 肖勇 姜伟 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第5期34-42,共9页
The low laser induced damage threshold of the KH2PO4 crystal seriously restricts the output power of inertial confinement fusion.The micro-waviness on the KH2PO4 surface processed by single point diamond turning has a... The low laser induced damage threshold of the KH2PO4 crystal seriously restricts the output power of inertial confinement fusion.The micro-waviness on the KH2PO4 surface processed by single point diamond turning has a significant influence on the damage threshold.In this paper,the influence of micro-waviness on the damage threshold of the KH2PO4 crystal and the chief sources introducing the micro-waviness are analysed based on the combination of the Fourier modal theory and the power spectrum density method.Research results indicate that among the sub-wavinesses with different characteristic spatial frequencies there exists the most dangerous frequency which greatly reduces the damage threshold,although it may not occupy the largest proportion in the original surface.The experimental damage threshold is basically consistent with the theoretical calculation.For the processing parameters used,the leading frequency of micro-waviness which causes the damage threshold to decrease is between 350-1 μm-1 and 30-1 μm-1,especially between 90-1 μm-1 and 200-1 μm-1.Based on the classification study of the time frequencies of microwaviness,we find that the axial vibration of the spindle is the chief source introducing the micro-waviness,nearly all the leading frequencies are related to the practical spindle frequency(about 6.68 Hz,400 r/min) and a special middle frequency(between 1.029 Hz and 1.143 Hz). 展开更多
关键词 laser induced damage threshold micro-waviness fourier modal theory power spectrum density
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Rough singular integrals associated with surfaces of Van der Corput type 被引量:2
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作者 LIU Feng WU Huo-xiong 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2014年第1期86-100,共15页
In this paper, the authors establish the LV-mapping properties for a class of singular integrals along surfaces in Rn of the form {Ф(lul)u' : u ε ]t^n} as well as the related maimal operators provided that the f... In this paper, the authors establish the LV-mapping properties for a class of singular integrals along surfaces in Rn of the form {Ф(lul)u' : u ε ]t^n} as well as the related maimal operators provided that the function Ф satisfies certain oscillatory integral estimates of Van der Corput type, and the integral kernels are given by the radial function h E ε△γ(R+) for γ 〉 1 and the sphere function ΩεFβ(S^n-1) for someβ 〉 0 which is distinct from HI(Sn-1). 展开更多
关键词 42B20 42B25 42B30 Singular integrals surfaces of Van der Corput type maximal operators Littlewood-Paley theory fourier transform estimates
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A Reexamination on the Problem of Advanced Response
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作者 谭天荣 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2003年第2期261-269,共9页
In the theory of signal analysis, the existence of the advanced response, whose appearance is earlier than the input, violates the law of causation. It is believed that the presence of advanced response is due to unre... In the theory of signal analysis, the existence of the advanced response, whose appearance is earlier than the input, violates the law of causation. It is believed that the presence of advanced response is due to unreasonable setting of the characteristic of the system. Hereof, by means of nonstandard analysis, it is concluded that the advanced response arises from the course of Fourier analysis other than the transmission process of the signal. 展开更多
关键词 nonstandard analysis theory: fourier analysis δ-function SIGNAL advanced response
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