The filter operator used in normal multichannel matching filter is physically realizable.This filter operator only delays seismic data in the filtering process.A noncausal multichannel matching filter based on a least...The filter operator used in normal multichannel matching filter is physically realizable.This filter operator only delays seismic data in the filtering process.A noncausal multichannel matching filter based on a least squares criterion is proposed to resolve the problem in which predicted multiple model data is Iater than real data.The diferences between causal and noncausal multichannel matching filters are compared using a synthetic shot gather,which demonstrates the validity of the noncausal matching filter.In addition,a variable length sliding window which changes with ofset and layer velocity is proposed to solve the count of events increasing with increasing ofset in a fixed Iength sliding window.This variable length sliding window is also introduced into the modified and expanded multichannel matching filter.This method is applied to the Pluto1.5 synthetic data set.The benefits of the non.causal filter operator and variable length sliding window are demonstrated bv the good multiple attenuation result.展开更多
Reversible watermarking technique enables to extract embedded information without any loss of the host signal. For the reduction of the embedding distortion, a desirable reversible watermarking approach should exploit...Reversible watermarking technique enables to extract embedded information without any loss of the host signal. For the reduction of the embedding distortion, a desirable reversible watermarking approach should exploit efficient prediction way to generate prediction errors with a smaller magnitude for expansion embedding. In this paper, we present a reversible audio watermarking scheme based on a new non-causal prediction method and embedding strategy. The proposed non-causal prediction method provides non-integer prediction errors and the proposed expansion embedding strategy can proceed them for a lower embedding distortion. Experimental results have shown that the proposed reversible technique has a lower embedding distortion for the same embedding payload in comparison with the existing state-of-the-art works.展开更多
This study investigated the impact of financial sector development on domestic investment in selected countries of the Economic Community of West African States(ECOWAS)for the years 1985–2017.The study employed the a...This study investigated the impact of financial sector development on domestic investment in selected countries of the Economic Community of West African States(ECOWAS)for the years 1985–2017.The study employed the augmented mean group procedure,which accounts for country-specific heterogeneity and crosssectional dependence,and the Granger non-causality test to test for causality in the presence of cross-sectional dependence.The results show that(1)The impact of financial sector development on domestic investment depends on the measure of financial sector development utilised;(2)Domestic credit to the private sector has a positive but insignificant impact on domestic investment in ECOWAS,whereas banking intermediation efficiency(i.e.,ability of the banks to transform deposits into credit)and broad money supply negatively and significant influence domestic investment;(3)Cross-country differences exist in the impact of financial sector development on domestic investment in the selected ECOWAS countries;and(4)Domestic credit to the private sector Granger causes domestic investment in ECOWAS.The study recommends careful consideration in the measure of financial development that is utilised as a policy instrument to foster domestic investment.We also highlight the importance of employing country-specific domestic investment policies to avoid blanket policy measures.Domestic credit to the private sector should be given priority when forecasting domestic investment into the future.展开更多
The origin of the universe?The origin of free will?The origin of space?Or simply the appearance of something out of nothing,with no causal before,likes a probability that transforms into an unpredictable particle actu...The origin of the universe?The origin of free will?The origin of space?Or simply the appearance of something out of nothing,with no causal before,likes a probability that transforms into an unpredictable particle actuality in quantum physics.In short,does better explanation for such questions await us?Or are we hamstrung by our tendency for“cause-and-effect”explanations or“something vs.nothing”ways of forcing the options?This essay explores the notion of beginnings-that is,the possibility of something from nothing.It begins by clarifying how the meaning of such terms is being intended,for example the question of whether the moon if no one sees it qualifies as a nothing,the question of an uncaused something or an effect minus an antecedent of any kind.In short,what does a something-from-nothing entail?And what is a something in the first place,as Heidegger asks in his essay,“What Is a Thing?”Having sketched out notions of“something”and“nothing”,the discussion proceeds to the central question,namely the possibility of a something from nothing.What is something?What is nothing?It may be that we need new categories of understanding for a better answer.This essay suggests such a quest.展开更多
In this paper, using the Guichardet space technique, the relationship between Fermion quantum stochastic calculus and non-causal calculus in Segal space L^2(H) is discussed, and an anticipating quantum stochastic calc...In this paper, using the Guichardet space technique, the relationship between Fermion quantum stochastic calculus and non-causal calculus in Segal space L^2(H) is discussed, and an anticipating quantum stochastic calculus is naturally given.展开更多
This study investigated the impact of a non-causative fault on the dynamic response of a nearby lined tunnel under the incidence of plane SV waves using the indirect boundary element method.The effects of several crit...This study investigated the impact of a non-causative fault on the dynamic response of a nearby lined tunnel under the incidence of plane SV waves using the indirect boundary element method.The effects of several critical parameters,such as the incident frequency,the inclination degree of the fault,the distance between the fault and the tunnel on the hoop stress of the lined inner and outer walls,were explored intensively.The numerical results indicated that the non-causative fault could significantly change the hoop stress distribution of inner and outer surfaces of the tunnels.In general,for the vertically incident seismic waves,when the tunnel was located in the foot wall(under the fault),the hoop stress within the tunnel was significantly greater than that of the tunnels in the non-fault half space,with an amplification factor of up to 117%.The amplification effect became more pronounced as the fault dip angle increased.However,when the tunnel was located in the hanging wall(above the fault),the non-causative fault could produce a significant shielding effect on the dynamic response of the tunnel under high frequency wave incidence,with the reduction of hoop stress being up to 81%.For lowfrequency waves,though,the fault could lead to an increase of the hoop stress of the tunnel of up to 152%.The research results will provide a reference for the seismic design and safety protection of underground structures in non-causative fault sites.展开更多
To identify the unsteady°uid dynamic model for a solid moving in the°uid,a new identication method that operates in the continuous time domain is proposed.It is illustrated that this new identication method ...To identify the unsteady°uid dynamic model for a solid moving in the°uid,a new identication method that operates in the continuous time domain is proposed.It is illustrated that this new identication method is more accurate and appropriate for identifying unsteady°uid dynamic model in incompressible°ow in comparison with the classical frequency domain or discrete domain method.This new method is applied to identify the unsteady°uid dynamic models of a NACA0012 airfoil and the e®ect of the°uid viscosity on the model parameter is analyzed.The result shows that the added mass in viscous°ow is dependent on the input signal frequency and is exactly the added mass in inviscid°ow when the frequency approaches innity.Based on this discovery,the long controversy on the relationship of added mass between viscous and inviscid°ow is solved.Then,the enlightenment of this discovery on the identication of both linear and nonlinear unsteady aerodynamic model in incompressible°ow is illustrated.At last,the advantage of the new acquired unsteady°uid dynamic model is discussed in comparison with the classical quasi-steady aerodynamic model.展开更多
基金supported by the National 863 Program (Grant No. 2006AA09A102-09)the National 973 Program (GrantNo. 2007CB209606)
文摘The filter operator used in normal multichannel matching filter is physically realizable.This filter operator only delays seismic data in the filtering process.A noncausal multichannel matching filter based on a least squares criterion is proposed to resolve the problem in which predicted multiple model data is Iater than real data.The diferences between causal and noncausal multichannel matching filters are compared using a synthetic shot gather,which demonstrates the validity of the noncausal matching filter.In addition,a variable length sliding window which changes with ofset and layer velocity is proposed to solve the count of events increasing with increasing ofset in a fixed Iength sliding window.This variable length sliding window is also introduced into the modified and expanded multichannel matching filter.This method is applied to the Pluto1.5 synthetic data set.The benefits of the non.causal filter operator and variable length sliding window are demonstrated bv the good multiple attenuation result.
基金Supported by the National Natural Science Foundation of China (61272414the Science and Technology Project of Guangzhou Province(2012J4100108)the Jinan University Outstanding Postgraduate Research and Innovation Program, Jinan University Outstanding Undergraduate Scientific Research Innovation Cultivation Project
文摘Reversible watermarking technique enables to extract embedded information without any loss of the host signal. For the reduction of the embedding distortion, a desirable reversible watermarking approach should exploit efficient prediction way to generate prediction errors with a smaller magnitude for expansion embedding. In this paper, we present a reversible audio watermarking scheme based on a new non-causal prediction method and embedding strategy. The proposed non-causal prediction method provides non-integer prediction errors and the proposed expansion embedding strategy can proceed them for a lower embedding distortion. Experimental results have shown that the proposed reversible technique has a lower embedding distortion for the same embedding payload in comparison with the existing state-of-the-art works.
文摘This study investigated the impact of financial sector development on domestic investment in selected countries of the Economic Community of West African States(ECOWAS)for the years 1985–2017.The study employed the augmented mean group procedure,which accounts for country-specific heterogeneity and crosssectional dependence,and the Granger non-causality test to test for causality in the presence of cross-sectional dependence.The results show that(1)The impact of financial sector development on domestic investment depends on the measure of financial sector development utilised;(2)Domestic credit to the private sector has a positive but insignificant impact on domestic investment in ECOWAS,whereas banking intermediation efficiency(i.e.,ability of the banks to transform deposits into credit)and broad money supply negatively and significant influence domestic investment;(3)Cross-country differences exist in the impact of financial sector development on domestic investment in the selected ECOWAS countries;and(4)Domestic credit to the private sector Granger causes domestic investment in ECOWAS.The study recommends careful consideration in the measure of financial development that is utilised as a policy instrument to foster domestic investment.We also highlight the importance of employing country-specific domestic investment policies to avoid blanket policy measures.Domestic credit to the private sector should be given priority when forecasting domestic investment into the future.
文摘The origin of the universe?The origin of free will?The origin of space?Or simply the appearance of something out of nothing,with no causal before,likes a probability that transforms into an unpredictable particle actuality in quantum physics.In short,does better explanation for such questions await us?Or are we hamstrung by our tendency for“cause-and-effect”explanations or“something vs.nothing”ways of forcing the options?This essay explores the notion of beginnings-that is,the possibility of something from nothing.It begins by clarifying how the meaning of such terms is being intended,for example the question of whether the moon if no one sees it qualifies as a nothing,the question of an uncaused something or an effect minus an antecedent of any kind.In short,what does a something-from-nothing entail?And what is a something in the first place,as Heidegger asks in his essay,“What Is a Thing?”Having sketched out notions of“something”and“nothing”,the discussion proceeds to the central question,namely the possibility of a something from nothing.What is something?What is nothing?It may be that we need new categories of understanding for a better answer.This essay suggests such a quest.
文摘In this paper, using the Guichardet space technique, the relationship between Fermion quantum stochastic calculus and non-causal calculus in Segal space L^2(H) is discussed, and an anticipating quantum stochastic calculus is naturally given.
基金supported by the National Natural Science Foundation of China(Grant Nos.51878434,51878108)Natural Science Foundation of Tianjin(Grant No.18JCZDJC 39200)Program of Tianjin Science and Technology Plan(Grant No.18ZXGDGX00050).
文摘This study investigated the impact of a non-causative fault on the dynamic response of a nearby lined tunnel under the incidence of plane SV waves using the indirect boundary element method.The effects of several critical parameters,such as the incident frequency,the inclination degree of the fault,the distance between the fault and the tunnel on the hoop stress of the lined inner and outer walls,were explored intensively.The numerical results indicated that the non-causative fault could significantly change the hoop stress distribution of inner and outer surfaces of the tunnels.In general,for the vertically incident seismic waves,when the tunnel was located in the foot wall(under the fault),the hoop stress within the tunnel was significantly greater than that of the tunnels in the non-fault half space,with an amplification factor of up to 117%.The amplification effect became more pronounced as the fault dip angle increased.However,when the tunnel was located in the hanging wall(above the fault),the non-causative fault could produce a significant shielding effect on the dynamic response of the tunnel under high frequency wave incidence,with the reduction of hoop stress being up to 81%.For lowfrequency waves,though,the fault could lead to an increase of the hoop stress of the tunnel of up to 152%.The research results will provide a reference for the seismic design and safety protection of underground structures in non-causative fault sites.
文摘To identify the unsteady°uid dynamic model for a solid moving in the°uid,a new identication method that operates in the continuous time domain is proposed.It is illustrated that this new identication method is more accurate and appropriate for identifying unsteady°uid dynamic model in incompressible°ow in comparison with the classical frequency domain or discrete domain method.This new method is applied to identify the unsteady°uid dynamic models of a NACA0012 airfoil and the e®ect of the°uid viscosity on the model parameter is analyzed.The result shows that the added mass in viscous°ow is dependent on the input signal frequency and is exactly the added mass in inviscid°ow when the frequency approaches innity.Based on this discovery,the long controversy on the relationship of added mass between viscous and inviscid°ow is solved.Then,the enlightenment of this discovery on the identication of both linear and nonlinear unsteady aerodynamic model in incompressible°ow is illustrated.At last,the advantage of the new acquired unsteady°uid dynamic model is discussed in comparison with the classical quasi-steady aerodynamic model.
