The dynamic behavior of a two-degree-of-freedom oblique impact system consisted of two pendulums with non-fixed impact positions is investigated. The relations between the restitution coefficient, the friction coeffic...The dynamic behavior of a two-degree-of-freedom oblique impact system consisted of two pendulums with non-fixed impact positions is investigated. The relations between the restitution coefficient, the friction coefficient, as well as other parameters of the system and the states before or after impact, are clarified in this oblique impact process. The existence criterion of single impact periodic-n subharrnonic motions is deduced based on the Poincare map method and the oblique impact relations with non-fixed impact positions. The stability of these subharrnonic periodic motions is analyzed by the Floquet theory, and the formulas to calculate the Flocluet multipliers are given. The validity of this method is shown through numerical simulation. At the same time, the probability distribution of impact positions in this oblique system with nonfixed impact positions is analyzed.展开更多
Enhanced speech based on the traditional wavelet threshold function had auditory oscillation distortion and the low signal-to-noise ratio (SNR). In order to solve these problems, a new continuous differentiable thresh...Enhanced speech based on the traditional wavelet threshold function had auditory oscillation distortion and the low signal-to-noise ratio (SNR). In order to solve these problems, a new continuous differentiable threshold function for speech enhancement was presented. Firstly, the function adopted narrow threshold areas, preserved the smaller signal speech, and improved the speech quality; secondly, based on the properties of the continuous differentiable and non-fixed deviation, each area function was attained gradually by using the method of mathematical derivation. It ensured that enhanced speech was continuous and smooth; it removed the auditory oscillation distortion; finally, combined with the Bark wavelet packets, it further improved human auditory perception. Experimental results show that the segmental SNR and PESQ (perceptual evaluation of speech quality) of the enhanced speech using this method increase effectively, compared with the existing speech enhancement algorithms based on wavelet threshold.展开更多
Labor Contract Law receives mixed evaluations since its implementation.The call for the amendment is hot and even some scholars regard it as the"tiger in the road"which hinders the economic development. The ...Labor Contract Law receives mixed evaluations since its implementation.The call for the amendment is hot and even some scholars regard it as the"tiger in the road"which hinders the economic development. The Central Committee of the Communist Party of China pays high attention to the construction of harmonious labor relation and the amendment has been a top priority. Labor Contract Law leads to two"deadlocks"of which the entrepreneurs are afraid. The first one is that the non-fixed term labor contract cannot be cancelled and the second one is that they must pay the economic compensation at the expiration of contract. These two rules hinder the employment enthusiasm of entrepreneurs. The current laws have excessive expectation for the non-fixed term labor contract and too strict regulations; as for the economic compensation at the expiration of contract, it increases the enterprise cost. The amendment of these two articles will benefit the recovery of Chinese economy and make the labor relation more harmonious.展开更多
In 2020,Niu et al.[Cryptogr.Commun.,2020,12(2):165–185]studied the fixed points of involutions over the finite field with q-elements.This paper further discusses the relationship between the fixed points set and the ...In 2020,Niu et al.[Cryptogr.Commun.,2020,12(2):165–185]studied the fixed points of involutions over the finite field with q-elements.This paper further discusses the relationship between the fixed points set and the non-fixed points set of two involutions f_(1)(x)and f_(2)(x)over the finite field F_(q),and then obtains a necessary and sufficient condition for that the composite function f_(1)■f_(2)(x)is also an involution over F_(q).In particular,a special class of involutions over some finite fields is determined completely.展开更多
文摘The dynamic behavior of a two-degree-of-freedom oblique impact system consisted of two pendulums with non-fixed impact positions is investigated. The relations between the restitution coefficient, the friction coefficient, as well as other parameters of the system and the states before or after impact, are clarified in this oblique impact process. The existence criterion of single impact periodic-n subharrnonic motions is deduced based on the Poincare map method and the oblique impact relations with non-fixed impact positions. The stability of these subharrnonic periodic motions is analyzed by the Floquet theory, and the formulas to calculate the Flocluet multipliers are given. The validity of this method is shown through numerical simulation. At the same time, the probability distribution of impact positions in this oblique system with nonfixed impact positions is analyzed.
基金Project(61072087) supported by the National Natural Science Foundation of ChinaProject(2011-035) supported by Shanxi Province Scholarship Foundation, China+2 种基金Project(20120010) supported by Universities High-tech Foundation Projects, ChinaProject (2013021016-1) supported by the Youth Science and Technology Foundation of Shanxi Province, ChinaProjects(2013011016-1, 2012011014-1) supported by the Natural Science Foundation of Shanxi Province, China
文摘Enhanced speech based on the traditional wavelet threshold function had auditory oscillation distortion and the low signal-to-noise ratio (SNR). In order to solve these problems, a new continuous differentiable threshold function for speech enhancement was presented. Firstly, the function adopted narrow threshold areas, preserved the smaller signal speech, and improved the speech quality; secondly, based on the properties of the continuous differentiable and non-fixed deviation, each area function was attained gradually by using the method of mathematical derivation. It ensured that enhanced speech was continuous and smooth; it removed the auditory oscillation distortion; finally, combined with the Bark wavelet packets, it further improved human auditory perception. Experimental results show that the segmental SNR and PESQ (perceptual evaluation of speech quality) of the enhanced speech using this method increase effectively, compared with the existing speech enhancement algorithms based on wavelet threshold.
基金Projects of the National Social Science Foundation of China“research on the response of the labor standard under new normal for the group hostility between capital and labor”(15BGL184)
文摘Labor Contract Law receives mixed evaluations since its implementation.The call for the amendment is hot and even some scholars regard it as the"tiger in the road"which hinders the economic development. The Central Committee of the Communist Party of China pays high attention to the construction of harmonious labor relation and the amendment has been a top priority. Labor Contract Law leads to two"deadlocks"of which the entrepreneurs are afraid. The first one is that the non-fixed term labor contract cannot be cancelled and the second one is that they must pay the economic compensation at the expiration of contract. These two rules hinder the employment enthusiasm of entrepreneurs. The current laws have excessive expectation for the non-fixed term labor contract and too strict regulations; as for the economic compensation at the expiration of contract, it increases the enterprise cost. The amendment of these two articles will benefit the recovery of Chinese economy and make the labor relation more harmonious.
基金supported by the Notional Natural Science Foundation of China(Grant No.12071321).
文摘In 2020,Niu et al.[Cryptogr.Commun.,2020,12(2):165–185]studied the fixed points of involutions over the finite field with q-elements.This paper further discusses the relationship between the fixed points set and the non-fixed points set of two involutions f_(1)(x)and f_(2)(x)over the finite field F_(q),and then obtains a necessary and sufficient condition for that the composite function f_(1)■f_(2)(x)is also an involution over F_(q).In particular,a special class of involutions over some finite fields is determined completely.
