This paper proposes the continuous-time singular value decomposition (SVD) for the impulse response function, a special kind of Green’s functions, in order to find a set of singular functions and singular values so t...This paper proposes the continuous-time singular value decomposition (SVD) for the impulse response function, a special kind of Green’s functions, in order to find a set of singular functions and singular values so that the convolutions of such function with the set of singular functions on a specified domain are the solutions to the inhomogeneous differential equations for those singular functions. A numerical example was illustrated to verify the proposed method. Besides the continuous-time SVD, a discrete-time SVD is also presented for the impulse response function, which is modeled using a Toeplitz matrix in the discrete system. The proposed method has broad applications in signal processing, dynamic system analysis, acoustic analysis, thermal analysis, as well as macroeconomic modeling.展开更多
The paper deals with impulse switching function which are used as exciting functions of one- and multidimensional state-space models of power electronic converters. Obviously, these functions are harmonic but using po...The paper deals with impulse switching function which are used as exciting functions of one- and multidimensional state-space models of power electronic converters. Obviously, these functions are harmonic but using power converters they can be strongly non-harmonic, sometimes piecewise constants with zero spaces between them. Then, one deals with power series of time pulses. The impulse switching functions which are orthogonal ones can be derived from these series. The new impulse switching functions are created using Z-transform, inverse Z-transform and numerical series/sequences. The impulse switching functions created this way can be used for both steady- and transient state investigation of converters.展开更多
Delta function is an important function in mathematics and physics. In this paper, the Laplace transforms of δ(t)and δ(t-τ)have been discussed in detail. After the Laplace transform of δ(t)is analyzed, the author ...Delta function is an important function in mathematics and physics. In this paper, the Laplace transforms of δ(t)and δ(t-τ)have been discussed in detail. After the Laplace transform of δ(t)is analyzed, the author has found that three aspects should be taken into account, i.e. τ→0+, τ→0- andτ=0; and it is the same with the Laplace transform of δ(t-τ). Then the results of the Laplace transform of Delta function have been obtained in a rigorous and comprehensive sense.展开更多
In this paper, we investigate the stability of a class of impulsive functional differential equations by using Lyapunov functional and Jensen＇s inequality. Some new stability theorems are obtained. Examples are given...In this paper, we investigate the stability of a class of impulsive functional differential equations by using Lyapunov functional and Jensen＇s inequality. Some new stability theorems are obtained. Examples are given to demonstrate the advantage of the obtained results.展开更多
In this paper, the Razumikhin approach is applied to the study of both p-th moment and almost sure stability on a general decay for a class of impulsive stochastic functional differential systems with Markovian switch...In this paper, the Razumikhin approach is applied to the study of both p-th moment and almost sure stability on a general decay for a class of impulsive stochastic functional differential systems with Markovian switching. Based on the Lyapunov-Razumikhin methods, some sufficient conditions are derived to check the stability of impulsive stochastic functional differential systems with Markovian switching. One numerical example is provided to demonstrate the effectiveness of the results.展开更多
From the perspective of long-term and short-term, the methods of TY causality test, generalized impulse response function, variance decomposition were used to investigate the impacts of international oil prices and ma...From the perspective of long-term and short-term, the methods of TY causality test, generalized impulse response function, variance decomposition were used to investigate the impacts of international oil prices and macroeconomic variables on Chinese gold, silver and platinum prices, but also the feedback effects of Chinese precious metal prices under this impact. The results show that international oil prices play an important role in precious metal price variation both in long-term and short-term, and exchange rate only has an effect in short-term, while interest rate is ineffective in predicting precious metal prices. In addition, precious metal prices have some feedback effects on international oil prices and interest rate in short-term.展开更多
In this paper,we highlight some recent developments of a new route to evaluate macroeconomic policy effects,which are investigated under the framework with potential outcomes.First,this paper begins with a brief intro...In this paper,we highlight some recent developments of a new route to evaluate macroeconomic policy effects,which are investigated under the framework with potential outcomes.First,this paper begins with a brief introduction of the basic model setup in modern econometric analysis of program evaluation.Secondly,primary attention goes to the focus on causal effect estimation of macroeconomic policy with single time series data together with some extensions to multiple time series data.Furthermore,we examine the connection of this new approach to traditional macroeconomic models for policy analysis and evaluation.Finally,we conclude by addressing some possible future research directions in statistics and econometrics.展开更多
A scheme for the impulsive control of nonlinear systems with time-varying delays is investigated in this paper. Based on the Lyapunov-like stability theorem for impulsive functional differential equations （FDEs）, so...A scheme for the impulsive control of nonlinear systems with time-varying delays is investigated in this paper. Based on the Lyapunov-like stability theorem for impulsive functional differential equations （FDEs）, some sufficient conditions are presented to guarantee the uniform asymptotic stability of impulsively controlled nonlinear systems with time-varying delays. These conditions are more effective and less conservative than those obtained. Finally, two numerical examples are provided to demonstrate the effectiveness of the proposed method.展开更多
Consideration of structure-foundation-soil dynamic interaction is a basic requirement in the evaluation of the seismic safety of nuclear power facilities. An efficient and accurate dynamic interaction numerical model ...Consideration of structure-foundation-soil dynamic interaction is a basic requirement in the evaluation of the seismic safety of nuclear power facilities. An efficient and accurate dynamic interaction numerical model in the time domain has become an important topic of current research. In this study, the scaled boundary finite element method （SBFEM） is improved for use as an effective numerical approach with good application prospects. This method has several advantages, including dimensionality reduction, accuracy of the radial analytical solution, and unlike other boundary element methods, it does not require a fundamental solution. This study focuses on establishing a high performance scaled boundary finite element interaction analysis model in the time domain based on the acceleration unit-impulse response matrix, in which several new solution techniques, such as a dimensionless method to solve the interaction force, are applied to improve the numerical stability of the actual soil parameters and reduce the amount of calculation. Finally, the feasibility of the time domain methods are illustrated by the response of the nuclear power structure and the accuracy of the algorithms are dynamically verified by comparison with the refinement of a large-scale viscoelastic soil model.展开更多
Over the past 30 years China＇s economy has made tremendous development and going on the road of opening-up is an important aspect of the successful experience, which should be unswervingly adhered to in the further. ...Over the past 30 years China＇s economy has made tremendous development and going on the road of opening-up is an important aspect of the successful experience, which should be unswervingly adhered to in the further. However, rationally looking at how different the impact of foreign economic activities on China＇s economy and society is economic workers＇ main task. From 1982 to 2006, based on six categories of China＇s environmental indicators, the paper improves the entropy method to calculate the environmental pollution index which can represent China＇s overall environmental situation, uses the VAR model of the impulse response function and variance decomposition method to study the impact of foreign trade, FDI on China＇s environmental pollution in the long-term. The results show that, FDI and import trade is conducive to the improvement of the quality of our environment and export trade is the deterioration of our environment, ＂pollution haven＂ hypothesis is proved in China. Export trade is an important variable that aggravates environmental pollution.展开更多
Negative step response experimental method is used in wrist force sensor＇s dynamic performance calibration. The exciting manner of negative step response method is the same as wrist force sensor＇s load in working. T...Negative step response experimental method is used in wrist force sensor＇s dynamic performance calibration. The exciting manner of negative step response method is the same as wrist force sensor＇s load in working. This experimental method needn＇t special experiment equipments. Experiment＇s dynamic repeatability is good. So wrist force sensor＇s dynamic performance is suitable to be calibrated by negative step response method. A new correlation wavelet transfer method is studied. By wavelet transfer method, the signal is decomposed into two dimensional spaces of time-frequency. So the problem of negative step exciting energy concentrating in the low frequency band is solved. Correlation wavelet transfer doesn＇t require that wavelet primary function be orthogonal and needn＇t wavelet reconstruction. So analyzing efficiency is high. An experimental bench is designed and manufactured to load the wrist force sensor orthogonal excitation force/moment. A piezoelectric force sensor is used to setup soft trigger and calculate the value of negative step excitation. A wrist force sensor is calibrated. The pulse response function is calculated after negative step excitation and step response have been transformed to positive step excitation and step response. The pulse response function is transferred to frequency response function. The wrist force sensor＇s dynamic characteristics are identified by the frequency response function.展开更多
Cardiovascular system is a complex interactive system. The study of ventriculo_arterial coupling can be greatly helpful to reveal the mechanism and regularity of cardiovascular system diseases. The dynamic process of ...Cardiovascular system is a complex interactive system. The study of ventriculo_arterial coupling can be greatly helpful to reveal the mechanism and regularity of cardiovascular system diseases. The dynamic process of the ventriculo_arterial coupling is considered making use of E(t)_R model for the left ventricle and T_Y tube model for the arterial tree. The predicted pressure and flow waveforms agree well with the experimental data. The effects of the SA and LV properties on the LV/SA function and the optimal coupling of ventriculo_arterial are also discussed. The results have clinical significance.展开更多
A low jitter All-Digital Phase-Locked Loop （ADPLL） used as a clock generator is designed. The Digital-Controlled Oscillator （DCO） for this ADPLL is a seven-stage ring oscillator with the delay of each stage change...A low jitter All-Digital Phase-Locked Loop （ADPLL） used as a clock generator is designed. The Digital-Controlled Oscillator （DCO） for this ADPLL is a seven-stage ring oscillator with the delay of each stage changeable. Based on the Impulse Sensitivity Function （ISF） analysis, an effective way is proposed to reduce the ADPLL＇s jitter by the careful design of the sizes of the inverters used in the DCO with a simple architecture other than a complex one. The ADPLL is implemented in a 0.18μm CMOS process with 1.SV supply voltage, occupies 0.046mm^2 of on-chip area. According to the measured results, the ADPLL can operate from 108MHz to 304MHz, and the peak-to-peak jitter is 139ps when the DCO＇s output frequency is 188MHz.展开更多
This study investigates the extent of the influence of imported fishmeal price changes on the market price of pisciculture products. To date, there have been only a few insufficient researches on this topic in Japan. ...This study investigates the extent of the influence of imported fishmeal price changes on the market price of pisciculture products. To date, there have been only a few insufficient researches on this topic in Japan. This paper aims to reveal the causality relationship between the market price of imported fishmeal and the market price of pisciculture products using the granger causality test, and to simulate the market price of pisciculture products using impulse response functions as the price of imported fishmeal increases. The results of the granger causality test and impulse response function analyses were as follows： （1） there is a market linkage from the price of imported fishmeal to the market price of sea bream, but no causality with the market price yellowtail; and （2） this has a positive impact on the market price of sea bream when the price of imported fishmeal changes. Moreover, spillover effects were noticed in this simple scenario （at a market price of 800 yen/kg and one unit shock of 1 yen） of about 3 yen/kg.展开更多
This paper aims to examine the effects of oil price shocks on the manufacturing sector in Saudi Arabia during the period 2002-2014, using quarterly data. The paper has conducted a unit root test. The data are shown to...This paper aims to examine the effects of oil price shocks on the manufacturing sector in Saudi Arabia during the period 2002-2014, using quarterly data. The paper has conducted a unit root test. The data are shown to be non-stationary in the level, and they became stationary in the first difference for all variables. The co-integration model was applied, and the results indicated that no co-integrating equation exists, which means that there is no long run effect of oil price shocks on the manufacturing sector. Therefore, the paper estimated a VAR model, the results of which implied that oil price shocks do not affect the manufacturing sector in the short run, and it may have an effect on the manufacturing sector after 10 quarters according to the Impulse Response Function~ The recent fall of oil prices since June 2014 is just one round of a series of fluctuations, in the form of shocks, in oil prices. Nevertheless, a debate has arisen about the effect of this price falls on the world economy in general and on oil exporting countries in particular. The economy of Saudi Arabia, the major oil exporting country, is not an exception in this matter of course. The main objective of this paper is to estimate quantitatively, in the economy of Saudi Arabia, whether there exists an impact of oil price shockson the output of the manufacturing sector, and whether it is a positive （direct） or a negative （inverse） relationship. The focus on the manufacturing sector here is for two reasons. First, the Saudi economic planning and policy have long targeted to diversify the sources of generating GDP. The manufacturing sector is, no doubt, a very important element in this diversification process. Second, the increase in manufacturing sector （as a percentage of GDP） is one of the important measures and/or indicators of economic development. For both reasons, the researchers have chosen to study ＂the effect of oil price shocks on the Saudi manufacturing sector＂ in this paper.展开更多
In this paper, some theorems of uniform stability and uniform asymptotic stability for impulsive functional differential equations with infinite delay are proved by using Lyapunov functionals and Razumikhin techniques...In this paper, some theorems of uniform stability and uniform asymptotic stability for impulsive functional differential equations with infinite delay are proved by using Lyapunov functionals and Razumikhin techniques. An example is also proved at the end to illustrate the application of the obtained results.展开更多
This paper uses the method of upper and lower solutions and the monotone iterative technique to investigate the existence of maximal and minimal solutions of the periodic boundary value problem for first order impulsi...This paper uses the method of upper and lower solutions and the monotone iterative technique to investigate the existence of maximal and minimal solutions of the periodic boundary value problem for first order impulsive functional differential equations.展开更多
Many practical systems in physical and technical sciences have impulsive dynamical behaviors during the evolution process which can be modeled by impulsive differential equations. In this paper, we prove the approxima...Many practical systems in physical and technical sciences have impulsive dynamical behaviors during the evolution process which can be modeled by impulsive differential equations. In this paper, we prove the approximate controllability of control systems governed by a class of impulsive neutral stochastic functional differential system with state-dependent delay in Hilbert spaces. Sufficient conditions for approximate controllability of the control systems are established under the natural assumption that the corresponding linear system is approximately controllable. The results are obtained by using semigroup theory, stochastic analysis techniques, fixed point approach and abstract phase space axioms. An example is provided to illustrate the application of the obtained results.展开更多
Price discovery is one of the main functions of stock index futures.Using the daily closing prices of the CSI 300 index and its index futures from April 2010 to April 2012,this paper applies a vector error correction ...Price discovery is one of the main functions of stock index futures.Using the daily closing prices of the CSI 300 index and its index futures from April 2010 to April 2012,this paper applies a vector error correction model(VECM)and an impulse response function to conduct an empirical analysis on the price discovery function of index futures in China.This paper has the following four findings:(1)a solid cointegration relationship between the CSI 300 index and its index futures exists in the long run;(2)when prices deviate from the longterm equilibrium,the stock index reverses weakly,while the reversal of index futures is much stronger;(3)the daily lead-lag relationship between the prices of the CSI 300 index and its index futures contracts is not significant in the short run;()shocks from the spot market have a lasting impact upon the futures market,but not vice versa,due to the limited short-term adjustment ability of the spot market.展开更多
文摘This paper proposes the continuous-time singular value decomposition (SVD) for the impulse response function, a special kind of Green’s functions, in order to find a set of singular functions and singular values so that the convolutions of such function with the set of singular functions on a specified domain are the solutions to the inhomogeneous differential equations for those singular functions. A numerical example was illustrated to verify the proposed method. Besides the continuous-time SVD, a discrete-time SVD is also presented for the impulse response function, which is modeled using a Toeplitz matrix in the discrete system. The proposed method has broad applications in signal processing, dynamic system analysis, acoustic analysis, thermal analysis, as well as macroeconomic modeling.
文摘The paper deals with impulse switching function which are used as exciting functions of one- and multidimensional state-space models of power electronic converters. Obviously, these functions are harmonic but using power converters they can be strongly non-harmonic, sometimes piecewise constants with zero spaces between them. Then, one deals with power series of time pulses. The impulse switching functions which are orthogonal ones can be derived from these series. The new impulse switching functions are created using Z-transform, inverse Z-transform and numerical series/sequences. The impulse switching functions created this way can be used for both steady- and transient state investigation of converters.
基金Funded by by Natural Science Foundation Project of CQ CSTC (Grant No: cstc2012jjA50018)the Basic Research of Chongqing Municipal Education Commission (Grant No:KJ120613)
文摘Delta function is an important function in mathematics and physics. In this paper, the Laplace transforms of δ(t)and δ(t-τ)have been discussed in detail. After the Laplace transform of δ(t)is analyzed, the author has found that three aspects should be taken into account, i.e. τ→0+, τ→0- andτ=0; and it is the same with the Laplace transform of δ(t-τ). Then the results of the Laplace transform of Delta function have been obtained in a rigorous and comprehensive sense.
基金supported by the National Natural Science Foundation of China (No. 10871063)Scientific Research Fund of Hunan Provincial Education Department (No. 07A038)
文摘In this paper, we investigate the stability of a class of impulsive functional differential equations by using Lyapunov functional and Jensen＇s inequality. Some new stability theorems are obtained. Examples are given to demonstrate the advantage of the obtained results.
文摘In this paper, the Razumikhin approach is applied to the study of both p-th moment and almost sure stability on a general decay for a class of impulsive stochastic functional differential systems with Markovian switching. Based on the Lyapunov-Razumikhin methods, some sufficient conditions are derived to check the stability of impulsive stochastic functional differential systems with Markovian switching. One numerical example is provided to demonstrate the effectiveness of the results.
基金Project(13&ZD169)supported by the Major Program of the National Social Science Foundation,ChinaProject(13YJAZH149)supported by Research Project in Humanities and Social Sciences Conducted by the Ministry of Education,China+2 种基金Project(2011ZK2043)supported by the Key Program of the Soft Science Research Project of Hunan Province,ChinaProject(2015JJ2182)supported by Natural Science Foundation of Hunan Province of ChinaProject(2009JYJR035)supported by Emergency Project "The Study of International Financial Crisis" of Ministry of Education of China
文摘From the perspective of long-term and short-term, the methods of TY causality test, generalized impulse response function, variance decomposition were used to investigate the impacts of international oil prices and macroeconomic variables on Chinese gold, silver and platinum prices, but also the feedback effects of Chinese precious metal prices under this impact. The results show that international oil prices play an important role in precious metal price variation both in long-term and short-term, and exchange rate only has an effect in short-term, while interest rate is ineffective in predicting precious metal prices. In addition, precious metal prices have some feedback effects on international oil prices and interest rate in short-term.
基金the National Natural Science Foundation of China(71631004,Key Project)the National Science Fund for Distinguished Young Scholars(71625001)+2 种基金the Basic Scientific Center Project of National Science Foundation of China:Econometrics and Quantitative Policy Evaluation(71988101)the Science Foundation of Ministry of Education of China(19YJA910003)China Scholarship Council Funded Project(201806315045).
文摘In this paper,we highlight some recent developments of a new route to evaluate macroeconomic policy effects,which are investigated under the framework with potential outcomes.First,this paper begins with a brief introduction of the basic model setup in modern econometric analysis of program evaluation.Secondly,primary attention goes to the focus on causal effect estimation of macroeconomic policy with single time series data together with some extensions to multiple time series data.Furthermore,we examine the connection of this new approach to traditional macroeconomic models for policy analysis and evaluation.Finally,we conclude by addressing some possible future research directions in statistics and econometrics.
基金supported by the National Natural Science Foundation of China (Grant Nos 60534010,60774048,60728307,60804006 and 60521003)the National High Technology Research and Development Program of China (Grant No 2006AA04Z183)+1 种基金Liaoning Provincial Natural Science Foundation,China (Grant No 20062018)111 Project (Grant No B08015)
文摘A scheme for the impulsive control of nonlinear systems with time-varying delays is investigated in this paper. Based on the Lyapunov-like stability theorem for impulsive functional differential equations （FDEs）, some sufficient conditions are presented to guarantee the uniform asymptotic stability of impulsively controlled nonlinear systems with time-varying delays. These conditions are more effective and less conservative than those obtained. Finally, two numerical examples are provided to demonstrate the effectiveness of the proposed method.
基金the State Key Program of National Natural Science of China under Grant No.51138001Science Fund for Creative Research Groups of the National Natural Science Foundation of China under Grant No.51121005Open Research Fund Program of State key Laboratory of Hydro science and Engineering under Grant No.shlhse-2010-C-03
文摘Consideration of structure-foundation-soil dynamic interaction is a basic requirement in the evaluation of the seismic safety of nuclear power facilities. An efficient and accurate dynamic interaction numerical model in the time domain has become an important topic of current research. In this study, the scaled boundary finite element method （SBFEM） is improved for use as an effective numerical approach with good application prospects. This method has several advantages, including dimensionality reduction, accuracy of the radial analytical solution, and unlike other boundary element methods, it does not require a fundamental solution. This study focuses on establishing a high performance scaled boundary finite element interaction analysis model in the time domain based on the acceleration unit-impulse response matrix, in which several new solution techniques, such as a dimensionless method to solve the interaction force, are applied to improve the numerical stability of the actual soil parameters and reduce the amount of calculation. Finally, the feasibility of the time domain methods are illustrated by the response of the nuclear power structure and the accuracy of the algorithms are dynamically verified by comparison with the refinement of a large-scale viscoelastic soil model.
文摘Over the past 30 years China＇s economy has made tremendous development and going on the road of opening-up is an important aspect of the successful experience, which should be unswervingly adhered to in the further. However, rationally looking at how different the impact of foreign economic activities on China＇s economy and society is economic workers＇ main task. From 1982 to 2006, based on six categories of China＇s environmental indicators, the paper improves the entropy method to calculate the environmental pollution index which can represent China＇s overall environmental situation, uses the VAR model of the impulse response function and variance decomposition method to study the impact of foreign trade, FDI on China＇s environmental pollution in the long-term. The results show that, FDI and import trade is conducive to the improvement of the quality of our environment and export trade is the deterioration of our environment, ＂pollution haven＂ hypothesis is proved in China. Export trade is an important variable that aggravates environmental pollution.
基金National Hi-tech Research and Development Program of China(863 Program,No.2001AA42330).
文摘Negative step response experimental method is used in wrist force sensor＇s dynamic performance calibration. The exciting manner of negative step response method is the same as wrist force sensor＇s load in working. This experimental method needn＇t special experiment equipments. Experiment＇s dynamic repeatability is good. So wrist force sensor＇s dynamic performance is suitable to be calibrated by negative step response method. A new correlation wavelet transfer method is studied. By wavelet transfer method, the signal is decomposed into two dimensional spaces of time-frequency. So the problem of negative step exciting energy concentrating in the low frequency band is solved. Correlation wavelet transfer doesn＇t require that wavelet primary function be orthogonal and needn＇t wavelet reconstruction. So analyzing efficiency is high. An experimental bench is designed and manufactured to load the wrist force sensor orthogonal excitation force/moment. A piezoelectric force sensor is used to setup soft trigger and calculate the value of negative step excitation. A wrist force sensor is calibrated. The pulse response function is calculated after negative step excitation and step response have been transformed to positive step excitation and step response. The pulse response function is transferred to frequency response function. The wrist force sensor＇s dynamic characteristics are identified by the frequency response function.
文摘Cardiovascular system is a complex interactive system. The study of ventriculo_arterial coupling can be greatly helpful to reveal the mechanism and regularity of cardiovascular system diseases. The dynamic process of the ventriculo_arterial coupling is considered making use of E(t)_R model for the left ventricle and T_Y tube model for the arterial tree. The predicted pressure and flow waveforms agree well with the experimental data. The effects of the SA and LV properties on the LV/SA function and the optimal coupling of ventriculo_arterial are also discussed. The results have clinical significance.
文摘A low jitter All-Digital Phase-Locked Loop （ADPLL） used as a clock generator is designed. The Digital-Controlled Oscillator （DCO） for this ADPLL is a seven-stage ring oscillator with the delay of each stage changeable. Based on the Impulse Sensitivity Function （ISF） analysis, an effective way is proposed to reduce the ADPLL＇s jitter by the careful design of the sizes of the inverters used in the DCO with a simple architecture other than a complex one. The ADPLL is implemented in a 0.18μm CMOS process with 1.SV supply voltage, occupies 0.046mm^2 of on-chip area. According to the measured results, the ADPLL can operate from 108MHz to 304MHz, and the peak-to-peak jitter is 139ps when the DCO＇s output frequency is 188MHz.
文摘This study investigates the extent of the influence of imported fishmeal price changes on the market price of pisciculture products. To date, there have been only a few insufficient researches on this topic in Japan. This paper aims to reveal the causality relationship between the market price of imported fishmeal and the market price of pisciculture products using the granger causality test, and to simulate the market price of pisciculture products using impulse response functions as the price of imported fishmeal increases. The results of the granger causality test and impulse response function analyses were as follows： （1） there is a market linkage from the price of imported fishmeal to the market price of sea bream, but no causality with the market price yellowtail; and （2） this has a positive impact on the market price of sea bream when the price of imported fishmeal changes. Moreover, spillover effects were noticed in this simple scenario （at a market price of 800 yen/kg and one unit shock of 1 yen） of about 3 yen/kg.
文摘This paper aims to examine the effects of oil price shocks on the manufacturing sector in Saudi Arabia during the period 2002-2014, using quarterly data. The paper has conducted a unit root test. The data are shown to be non-stationary in the level, and they became stationary in the first difference for all variables. The co-integration model was applied, and the results indicated that no co-integrating equation exists, which means that there is no long run effect of oil price shocks on the manufacturing sector. Therefore, the paper estimated a VAR model, the results of which implied that oil price shocks do not affect the manufacturing sector in the short run, and it may have an effect on the manufacturing sector after 10 quarters according to the Impulse Response Function~ The recent fall of oil prices since June 2014 is just one round of a series of fluctuations, in the form of shocks, in oil prices. Nevertheless, a debate has arisen about the effect of this price falls on the world economy in general and on oil exporting countries in particular. The economy of Saudi Arabia, the major oil exporting country, is not an exception in this matter of course. The main objective of this paper is to estimate quantitatively, in the economy of Saudi Arabia, whether there exists an impact of oil price shockson the output of the manufacturing sector, and whether it is a positive （direct） or a negative （inverse） relationship. The focus on the manufacturing sector here is for two reasons. First, the Saudi economic planning and policy have long targeted to diversify the sources of generating GDP. The manufacturing sector is, no doubt, a very important element in this diversification process. Second, the increase in manufacturing sector （as a percentage of GDP） is one of the important measures and/or indicators of economic development. For both reasons, the researchers have chosen to study ＂the effect of oil price shocks on the Saudi manufacturing sector＂ in this paper.
基金Supported by NNSF of China (Grant No. 10671069)NSF of Shanghai (Grant No. 09ZR1408900)Shanghai Leading Academic Discipline Project (Grant No. B407)
文摘In this paper, some theorems of uniform stability and uniform asymptotic stability for impulsive functional differential equations with infinite delay are proved by using Lyapunov functionals and Razumikhin techniques. An example is also proved at the end to illustrate the application of the obtained results.
文摘This paper uses the method of upper and lower solutions and the monotone iterative technique to investigate the existence of maximal and minimal solutions of the periodic boundary value problem for first order impulsive functional differential equations.
基金supported by Indo-US Science and Technology Forum (IUSSTF), New Delhi, India and UGC Special Assistance Programme (SAP)DRS-Ⅱ,University Grants Commission, New Delhi, India (No. F.510/2/DRS/2009(SAP-Ⅰ)
文摘Many practical systems in physical and technical sciences have impulsive dynamical behaviors during the evolution process which can be modeled by impulsive differential equations. In this paper, we prove the approximate controllability of control systems governed by a class of impulsive neutral stochastic functional differential system with state-dependent delay in Hilbert spaces. Sufficient conditions for approximate controllability of the control systems are established under the natural assumption that the corresponding linear system is approximately controllable. The results are obtained by using semigroup theory, stochastic analysis techniques, fixed point approach and abstract phase space axioms. An example is provided to illustrate the application of the obtained results.
文摘Price discovery is one of the main functions of stock index futures.Using the daily closing prices of the CSI 300 index and its index futures from April 2010 to April 2012,this paper applies a vector error correction model(VECM)and an impulse response function to conduct an empirical analysis on the price discovery function of index futures in China.This paper has the following four findings:(1)a solid cointegration relationship between the CSI 300 index and its index futures exists in the long run;(2)when prices deviate from the longterm equilibrium,the stock index reverses weakly,while the reversal of index futures is much stronger;(3)the daily lead-lag relationship between the prices of the CSI 300 index and its index futures contracts is not significant in the short run;()shocks from the spot market have a lasting impact upon the futures market,but not vice versa,due to the limited short-term adjustment ability of the spot market.
