This article is concerned with a class of control systems with Markovian switching, in which an It5 formula for Markov-modulated processes is derived. Moreover, an optimal control law satisfying the generalized Hamilt...This article is concerned with a class of control systems with Markovian switching, in which an It5 formula for Markov-modulated processes is derived. Moreover, an optimal control law satisfying the generalized Hamilton-Jacobi-Bellman (HJB) equation with Markovian switching is characterized. Then, through the generalized HJB equation, we study an optimal consumption and portfolio problem with the financial markets of Markovian switching and inflation. Thus, we deduce the optimal policies and show that a modified Mutual Fund Theorem consisting of three funds holds. Finally, for the CRRA utility function, we explicitly give the optimal consumption and portfolio policies. Numerical examples are included to illustrate the obtained results.展开更多
Parameter estimation is defined as the process to adjust or optimize the model parameter using observations.A long-term problem in ensemble-based parameter estimation methods is that the parameters are assumed to be c...Parameter estimation is defined as the process to adjust or optimize the model parameter using observations.A long-term problem in ensemble-based parameter estimation methods is that the parameters are assumed to be constant during model integration.This assumption will cause underestimation of parameter ensemble spread,such that the parameter ensemble tends to collapse before an optimal solution is found.In this work,a two-stage inflation method is developed for parameter estimation,which can address the collapse of parameter ensemble due to the constant evolution of parameters.In the first stage,adaptive inflation is applied to the augmented states,in which the global scalar parameter is transformed to fields with spatial dependence.In the second stage,extra multiplicative inflation is used to inflate the scalar parameter ensemble to compensate for constant parameter evolution,where the inflation factor is determined according to the spread growth ratio of model states.The observation system simulation experiment with Community Earth System Model(CESM)shows that the second stage of the inflation scheme plays a crucial role in successful parameter estimation.With proper multiplicative inflation factors,the parameter estimation can effectively reduce the parameter biases,providing more accurate analyses.展开更多
The emergency transformation of various aspects of life and business these days requires prompt evaluation of autonomous vehicles.One of the primary reassessments deals with the applicability of the vehicle passive sa...The emergency transformation of various aspects of life and business these days requires prompt evaluation of autonomous vehicles.One of the primary reassessments deals with the applicability of the vehicle passive safety system to the protec-tion of arbitrarily positioned passengers.To mitigate possible risks caused by the simultaneous deployment of several big airbags,a new principle of their operation is required.Herein,the aspirated inflator for a driver airbag is developed that can provide 50L-airbag inflation within 30-40 ms.As a result,about 3/4 of the air is to be entrained into an airbag from the vehicle compartment.The process is initiated by a supersonic pulse jet(1/3 air volume)generated pyrotechnically.Then the Prandtl-Meyer problem formulation enables guiding linear and angular dimensions of the essential parts of the device.Accordingly,a family of experimental models of varied geometry is fabricated and tested to determine their operational effectiveness in a range of motive pressure within~3-7 MPa.Experiments are performed on a specially designed facility equipped with compressed-air tanks and a high-speed valve to mimic the inflator operation with the pyrotechnic gas generator.The aspirated inflator operability is characterized using multivariate measurements of pressure fields,high-speed video-recording of the airbag inflation process,and evaluation of aspiration(entrainment)ratio.The average volume aspiration ratio measured at 300 K is found to reach 2.8 and it’s expected to almost double at 1200 K.展开更多
This paper submits that the advantages gained by introducing a single currency at the domestic level, applies equally to the economy at the global level. The advantages gained are (1) a reduction of the inflation ra...This paper submits that the advantages gained by introducing a single currency at the domestic level, applies equally to the economy at the global level. The advantages gained are (1) a reduction of the inflation rate to one common rate (if required) amongst all states, (2) a possible reduced interest rate, (3) an expansion in investment, (4) an increase in development and trade due to the removal of uncertainty, (5) the reduction in transaction costs, and (6) the reduction in the cost of capital (Moshirian, 2004, p. 306). A single global currency has immediate implications in accounting for inflation as it presents an opportunity for the permanent removal of problems associated with accounting for inflation. This paper addresses the phenomenon of inflation and how accounting measurement and valuation associated with inflation is removed by the introduction of a single global currency.展开更多
A computational framework for parachute inflation is developed based on the immersed boundary/finite element approach within the open-source IBAMR library.The fluid motion is solved by Peskin's diffuse-interface i...A computational framework for parachute inflation is developed based on the immersed boundary/finite element approach within the open-source IBAMR library.The fluid motion is solved by Peskin's diffuse-interface immersed boundary(IB)method,which is attractive for simulating moving-boundary flows with large deformations.The adaptive mesh refinement technique is employed to reduce the computational cost while retain the desired resolution.The dynamic response of the parachute is solved with the finite element approach.The canopy and cables of the parachute system are modeled with the hyperelastic material.A tether force is introduced to impose rigidity constraints for the parachute system.The accuracy and reliability of the present framework is validated by simulating inflation of a constrained square plate.Application of the present framework on several canonical cases further demonstrates its versatility for simulation of parachute inflation.展开更多
A new congestion driven placement Algorithm is described based on the cell inflation. In this approach, the methods of probability estimation and star model are used to evaluate the routing of nets. Global placemen...A new congestion driven placement Algorithm is described based on the cell inflation. In this approach, the methods of probability estimation and star model are used to evaluate the routing of nets. Global placement can be done by using the algorithm of global optimization and slicing partitioning. The denotation of virtual area of cell is given to indicate not only the area of cell but also the routing demand.The virtual area of a cell is got by using the strategy of cell inflation, with which in the slicing partitioning, the routing congestion is eliminated. Further reduction in congestion is achieved by cell moving. The algorithm has been tested on a set of sample circuits from American companies, with great improvement in routablity having been obtained.展开更多
Suppression effect in multiple regression analysis may be more common in research than what is currently recognized. We have reviewed several literatures of interest which treats the concept and types of suppressor va...Suppression effect in multiple regression analysis may be more common in research than what is currently recognized. We have reviewed several literatures of interest which treats the concept and types of suppressor variables. Also, we have highlighted systematic ways to identify suppression effect in multiple regressions using statistics such as: R2, sum of squares, regression weight and comparing zero-order correlations with Variance Inflation Factor (VIF) respectively. We also establish that suppression effect is a function of multicollinearity;however, a suppressor variable should only be allowed in a regression analysis if its VIF is less than five (5).展开更多
The inflation mechanism is examined for a composite cylindrical tube composed of two incompressible rubber materials, and the inner surface of the tube is subjected to a suddenly applied radial pressure. The mathemati...The inflation mechanism is examined for a composite cylindrical tube composed of two incompressible rubber materials, and the inner surface of the tube is subjected to a suddenly applied radial pressure. The mathematical model of the problem is formulated, and the corresponding governing equation is reduced to a second-order ordinary differential equation by means of the incompressible condition of the material, the boundary conditions, and the continuity conditions of the radial displacement and the radial stress of the cylindrical tube. Moreover, the first integral of the equation is obtained. The qualitative analyses of static inflation and dynamic inflation of the tube are presented. Particularly, the effects of material parameters, structure parameters, and the radial pressure on radial inflation and nonlinearly periodic oscillation of the tube are discussed by combining numerical examples.展开更多
Taking the Hubble parameter directly as a function of the scalar field instead of as a function of time,H = H( ), we present a new exact solution in the new inflation model with induced gravity. This includes solution...Taking the Hubble parameter directly as a function of the scalar field instead of as a function of time,H = H( ), we present a new exact solution in the new inflation model with induced gravity. This includes solution which is inflation for < > end, and develops smoothly towards radiation-like evolution for ≥ end. The inflation is driven by the evolution of the field with inflation potential, V( ) = λ 2 v2)2.density, ns, is computed and ns lies well inside the limits set by the cosmic background explorer (COBE) satellite.the dex of the scalar effective cosmological constant Aeff tends to zero when inflation ends.展开更多
Taking the cosmological expansion rate directly as a function of field , H = H( ), we present a new exact solution to Einstein's equations that describe the evolution of cosmological chaotic inflation model. The i...Taking the cosmological expansion rate directly as a function of field , H = H( ), we present a new exact solution to Einstein's equations that describe the evolution of cosmological chaotic inflation model. The inflation is driven by the evolution of scalar field with inflation potential V( ) = λ 2 v2)2.8 ( 2- 2)2.The spectral indices of the scalar density ns and gravitational wave fluctuations ng are computed. The value of ns lies well inside the limits set by the cosmic background explorer satellite.展开更多
The inflation of a five-ring cone parachute with the airflow velocity of 18 m/s is studied based on the simplified arbitrary Lagrange Euler (SALE)/fluid-structure interaction (FSI) method. The numerical results of...The inflation of a five-ring cone parachute with the airflow velocity of 18 m/s is studied based on the simplified arbitrary Lagrange Euler (SALE)/fluid-structure interaction (FSI) method. The numerical results of the canopy shape, stability, opening load, and drag area are obtained, and they are well consistent with the experimental data gained from wind tunnel tests. The method is then used to simulate the opening process under different velocities. It is found that the first load shock affected by the velocity often occurs at the end of the initial inflation stage. For the first time, the phenomena that the inflation distance proportion coefficient increases and the dynamic load coefficient decreases, respectively, with the increase in the velocity are revealed. The above proposed method is competent to solve the large deformation problem without empirial coefficients, and can collect more space-time details of fluid-structure-motion information when it is compared with the traditional method.展开更多
The purpose of this study is to contribute to the literature by studying the effects of sudden changes both on crude oil import price and domestic gasoline price on inflation for Turkey, an emerging country. Since an ...The purpose of this study is to contribute to the literature by studying the effects of sudden changes both on crude oil import price and domestic gasoline price on inflation for Turkey, an emerging country. Since an inflation targeting regime is being carried out by the Central Bank of Turkey, determination of such effects is becoming more important. Therefore empirical evidence in this paper will serve as guidance for those countries, which have an in- flation targeting regime. Analyses have been done in the period of October 2005-December 2012 by Markovswitching vector autoregressive (MS-VAR) models which are successful in capturing the nonlinear properties of variables. Using MS-VAR analysis, it is found that there are 2 regimes in the analysis period. Furthermore, regime changes can be dated and the turning points of economic cycles can be determined. In addition, it is found that the effect of the changes in crude oil and domestic gasoline prices on consumer prices and core inflation is not the same under different regimes. Moreover, the sudden increase in gasoline price is more important for consumer price infla- tion than crude oil price shocks. Another finding is the presence of a pass-through effect from oil price and ga- soline price to core inflation.展开更多
We use Extended Merton model(EMM)for estimating the firm’s credit risks in the presence of inflation.We show quantitatively that inflation is an influential factor making either a benign or adverse effect on the firm...We use Extended Merton model(EMM)for estimating the firm’s credit risks in the presence of inflation.We show quantitatively that inflation is an influential factor making either a benign or adverse effect on the firm’s survival,supporting at the microeconomic level New Keynesian findings of the nonlinear inflation effect on output growth.Lower inflation increasing the firm’s expected rate of return can raise its mean year returns and decrease its default probability.Higher inflation,decreasing the expected rate return,makes the opposite effect.The magnitude of the adverse effect depends on the firm strength:for a steady firm,this effect is small,whereas for a weaker firm,it can be fatal.EMM is the only model taking account of inflation.It can be useful for banks or insurance companies estimating credit risks of commercial borrowers over the debt maturity,and for the firm’s management planning long-term business operations.展开更多
In this paper, the Holt’s exponential smoothing and Auto-Regressive Integrated Moving Average (ARIMA) models were used to forecast inflation rate of Zambia using the monthly consumer price index (CPI) data from May 2...In this paper, the Holt’s exponential smoothing and Auto-Regressive Integrated Moving Average (ARIMA) models were used to forecast inflation rate of Zambia using the monthly consumer price index (CPI) data from May 2010 to May 2014. Results show that the ARIMA ((12), 1, 0) is an adequate model which best fits the CPI time series data and is therefore suitable for forecasting CPI and subsequently the inflation rate. However, the choice of the Holt’s exponential smoothing is as good as an ARIMA model considering the smaller deviations in the mean absolute percentage error and mean square error. Moreover, the Holt’s exponential smoothing model is less complicated since you do not require specialised software to implement it as is the case for ARIMA models. The forecasted inflation rate for April and May, 2015 is 7.0 and 6.6 respectively.展开更多
We were interested, along this work, in the phenomena of the quintessence and the inflation due to the F-harmonic maps, in other words, in the functions of the scalar field such as the exponential and trigo-harmonic m...We were interested, along this work, in the phenomena of the quintessence and the inflation due to the F-harmonic maps, in other words, in the functions of the scalar field such as the exponential and trigo-harmonic maps. We showed that some F-harmonic map such as the trigonometric functions instead of the scalar field in the lagrangian, allow, in the absence of term of potential, reproduce the inflation. However, there are other F-harmonic maps such as exponential maps which can’t produce the inflation;the pressure and the density of this exponential harmonic field being both of the same sign. On the other hand, these exponential harmonic fields redraw well the phenomenon of the quintessence when the variation of these fields remains weak. The problem of coincidence, however remains.展开更多
Since July 2010,the prices of geographical indication products have risen with the occurrence of inflation.In contrast with other products,geographical indication products are distinct.The increasing prices of geograp...Since July 2010,the prices of geographical indication products have risen with the occurrence of inflation.In contrast with other products,geographical indication products are distinct.The increasing prices of geographical indication goods have their own necessities.From the perspective of the products,they are equipped with appreciation potential due to the cultural pe culiarities.From the historical standpoint,their prices have not been high as well as other agricultural products.Realistically,the increase in their prices results from the costs of labors and raw materials.Therefore,the prices of geographical indication products rise to catch up.Not only are their prices at a reasonable level,but also they are beneficial to increase peasants'income.In con clusion,it is necessary that the strategies which are different from those of other products be adopted to regulate and control the prices of geographical indication products.展开更多
The early universe inflation is well known as a promising theory to explain the origin of large-scale structure of universe and to solve the early universe pressing problems. For a reasonable inflation model, the pote...The early universe inflation is well known as a promising theory to explain the origin of large-scale structure of universe and to solve the early universe pressing problems. For a reasonable inflation model, the potential during inflation must be very flat, at least, in the direction of the inflaton. To construct the inflaton potential all the known related astrophysics observations should be included. For a general tree-level hybrid inflation potential, which is notdiscussed fully so far, the parameters in it are shown how to be constrained via the astrophysics data observed and to be obtained to the expected accuracy, and to be consistent with cosmology requirements.展开更多
We construct a general braneworld inflation scenario where the inflaton field evolves on the DGP brahe and curvature effects are taken into account via incorporation of the Gauss-Bonnet term in the bulk action. While ...We construct a general braneworld inflation scenario where the inflaton field evolves on the DGP brahe and curvature effects are taken into account via incorporation of the Gauss-Bonnet term in the bulk action. While induced gravity on the DGP brane modifies the IR limit of general relativity, the Gauss-Bonnet term in the bulk action modifies the UV sector of the theory. In this setup, the dynamics of perturbations on the brane are studied with details and some confrontation with recent observations are discussed. While the Einstein-Gauss-Bonnet inflation scenario favors only a red spectrum of the scalar perturbation, pure DGP and GBIG inflation models have the capacity to realize the blue spectrum too. In addition, the GBIG inflation scenario in the large field limit requires a smaller number of e-folds than other proposed scenarios in the same situation. For the tensor-to-scalar ratio, the GBIG inflation scenario g/yes a better fit with observationally supported value of R≈ 0.24.展开更多
This paper presents a new exact inflationary solution to the non-minimMly coupled scalar field. The inflation is driven by the evolution of a scalar field with inflation potential V(φ) = (λ/4)φ4 + b1φ2 + b2 ...This paper presents a new exact inflationary solution to the non-minimMly coupled scalar field. The inflation is driven by the evolution of a scalar field with inflation potential V(φ) = (λ/4)φ4 + b1φ2 + b2 + b3φ-2 + b4φ-4. The spectral index of the scalar density fluctuations ns is consistent with the result of WMAP3 (Wilkinson Microwave Anisotropy Probe 3) for ACDM (Lambda-Cold Dark Matter). This model relaxes the constraint to the quartic coupling constant. And it can enter smoothly into a radiation-dominated stage when inflation ends.展开更多
基金supported by National Natural Science Foundation of China(71171003)Anhui Natural Science Foundation(10040606003)Anhui Natural Science Foundation of Universities(KJ2012B019,KJ2013B023)
文摘This article is concerned with a class of control systems with Markovian switching, in which an It5 formula for Markov-modulated processes is derived. Moreover, an optimal control law satisfying the generalized Hamilton-Jacobi-Bellman (HJB) equation with Markovian switching is characterized. Then, through the generalized HJB equation, we study an optimal consumption and portfolio problem with the financial markets of Markovian switching and inflation. Thus, we deduce the optimal policies and show that a modified Mutual Fund Theorem consisting of three funds holds. Finally, for the CRRA utility function, we explicitly give the optimal consumption and portfolio policies. Numerical examples are included to illustrate the obtained results.
基金The National Key Research and Development Program under contract No.2017YFA0604202the Fundamental Research Funds for the Central Universities under contract No.B210201022the National Natural Science Foundation of China under contract Nos 42176003,41690124,41806032 and 41806038.
文摘Parameter estimation is defined as the process to adjust or optimize the model parameter using observations.A long-term problem in ensemble-based parameter estimation methods is that the parameters are assumed to be constant during model integration.This assumption will cause underestimation of parameter ensemble spread,such that the parameter ensemble tends to collapse before an optimal solution is found.In this work,a two-stage inflation method is developed for parameter estimation,which can address the collapse of parameter ensemble due to the constant evolution of parameters.In the first stage,adaptive inflation is applied to the augmented states,in which the global scalar parameter is transformed to fields with spatial dependence.In the second stage,extra multiplicative inflation is used to inflate the scalar parameter ensemble to compensate for constant parameter evolution,where the inflation factor is determined according to the spread growth ratio of model states.The observation system simulation experiment with Community Earth System Model(CESM)shows that the second stage of the inflation scheme plays a crucial role in successful parameter estimation.With proper multiplicative inflation factors,the parameter estimation can effectively reduce the parameter biases,providing more accurate analyses.
文摘The emergency transformation of various aspects of life and business these days requires prompt evaluation of autonomous vehicles.One of the primary reassessments deals with the applicability of the vehicle passive safety system to the protec-tion of arbitrarily positioned passengers.To mitigate possible risks caused by the simultaneous deployment of several big airbags,a new principle of their operation is required.Herein,the aspirated inflator for a driver airbag is developed that can provide 50L-airbag inflation within 30-40 ms.As a result,about 3/4 of the air is to be entrained into an airbag from the vehicle compartment.The process is initiated by a supersonic pulse jet(1/3 air volume)generated pyrotechnically.Then the Prandtl-Meyer problem formulation enables guiding linear and angular dimensions of the essential parts of the device.Accordingly,a family of experimental models of varied geometry is fabricated and tested to determine their operational effectiveness in a range of motive pressure within~3-7 MPa.Experiments are performed on a specially designed facility equipped with compressed-air tanks and a high-speed valve to mimic the inflator operation with the pyrotechnic gas generator.The aspirated inflator operability is characterized using multivariate measurements of pressure fields,high-speed video-recording of the airbag inflation process,and evaluation of aspiration(entrainment)ratio.The average volume aspiration ratio measured at 300 K is found to reach 2.8 and it’s expected to almost double at 1200 K.
文摘This paper submits that the advantages gained by introducing a single currency at the domestic level, applies equally to the economy at the global level. The advantages gained are (1) a reduction of the inflation rate to one common rate (if required) amongst all states, (2) a possible reduced interest rate, (3) an expansion in investment, (4) an increase in development and trade due to the removal of uncertainty, (5) the reduction in transaction costs, and (6) the reduction in the cost of capital (Moshirian, 2004, p. 306). A single global currency has immediate implications in accounting for inflation as it presents an opportunity for the permanent removal of problems associated with accounting for inflation. This paper addresses the phenomenon of inflation and how accounting measurement and valuation associated with inflation is removed by the introduction of a single global currency.
基金supported by the Open Project of Key Laboratory of Aerospace EDLA,CASC(No.EDL19092208)。
文摘A computational framework for parachute inflation is developed based on the immersed boundary/finite element approach within the open-source IBAMR library.The fluid motion is solved by Peskin's diffuse-interface immersed boundary(IB)method,which is attractive for simulating moving-boundary flows with large deformations.The adaptive mesh refinement technique is employed to reduce the computational cost while retain the desired resolution.The dynamic response of the parachute is solved with the finite element approach.The canopy and cables of the parachute system are modeled with the hyperelastic material.A tether force is introduced to impose rigidity constraints for the parachute system.The accuracy and reliability of the present framework is validated by simulating inflation of a constrained square plate.Application of the present framework on several canonical cases further demonstrates its versatility for simulation of parachute inflation.
文摘A new congestion driven placement Algorithm is described based on the cell inflation. In this approach, the methods of probability estimation and star model are used to evaluate the routing of nets. Global placement can be done by using the algorithm of global optimization and slicing partitioning. The denotation of virtual area of cell is given to indicate not only the area of cell but also the routing demand.The virtual area of a cell is got by using the strategy of cell inflation, with which in the slicing partitioning, the routing congestion is eliminated. Further reduction in congestion is achieved by cell moving. The algorithm has been tested on a set of sample circuits from American companies, with great improvement in routablity having been obtained.
文摘Suppression effect in multiple regression analysis may be more common in research than what is currently recognized. We have reviewed several literatures of interest which treats the concept and types of suppressor variables. Also, we have highlighted systematic ways to identify suppression effect in multiple regressions using statistics such as: R2, sum of squares, regression weight and comparing zero-order correlations with Variance Inflation Factor (VIF) respectively. We also establish that suppression effect is a function of multicollinearity;however, a suppressor variable should only be allowed in a regression analysis if its VIF is less than five (5).
基金supported by the National Natural Science Foundation of China (Nos. 10872045 and10721062)the Program for New Century Excellent Talents in University (No. NCET-09-0096)the Fundamental Research Funds for the Central Universities (No. DC10030104)
文摘The inflation mechanism is examined for a composite cylindrical tube composed of two incompressible rubber materials, and the inner surface of the tube is subjected to a suddenly applied radial pressure. The mathematical model of the problem is formulated, and the corresponding governing equation is reduced to a second-order ordinary differential equation by means of the incompressible condition of the material, the boundary conditions, and the continuity conditions of the radial displacement and the radial stress of the cylindrical tube. Moreover, the first integral of the equation is obtained. The qualitative analyses of static inflation and dynamic inflation of the tube are presented. Particularly, the effects of material parameters, structure parameters, and the radial pressure on radial inflation and nonlinearly periodic oscillation of the tube are discussed by combining numerical examples.
文摘Taking the Hubble parameter directly as a function of the scalar field instead of as a function of time,H = H( ), we present a new exact solution in the new inflation model with induced gravity. This includes solution which is inflation for < > end, and develops smoothly towards radiation-like evolution for ≥ end. The inflation is driven by the evolution of the field with inflation potential, V( ) = λ 2 v2)2.density, ns, is computed and ns lies well inside the limits set by the cosmic background explorer (COBE) satellite.the dex of the scalar effective cosmological constant Aeff tends to zero when inflation ends.
文摘Taking the cosmological expansion rate directly as a function of field , H = H( ), we present a new exact solution to Einstein's equations that describe the evolution of cosmological chaotic inflation model. The inflation is driven by the evolution of scalar field with inflation potential V( ) = λ 2 v2)2.8 ( 2- 2)2.The spectral indices of the scalar density ns and gravitational wave fluctuations ng are computed. The value of ns lies well inside the limits set by the cosmic background explorer satellite.
基金supported by the National Natural Science Foundation of China(No.11172137)the Aeronautical Science Foundation of China(No.20122910001)
文摘The inflation of a five-ring cone parachute with the airflow velocity of 18 m/s is studied based on the simplified arbitrary Lagrange Euler (SALE)/fluid-structure interaction (FSI) method. The numerical results of the canopy shape, stability, opening load, and drag area are obtained, and they are well consistent with the experimental data gained from wind tunnel tests. The method is then used to simulate the opening process under different velocities. It is found that the first load shock affected by the velocity often occurs at the end of the initial inflation stage. For the first time, the phenomena that the inflation distance proportion coefficient increases and the dynamic load coefficient decreases, respectively, with the increase in the velocity are revealed. The above proposed method is competent to solve the large deformation problem without empirial coefficients, and can collect more space-time details of fluid-structure-motion information when it is compared with the traditional method.
文摘The purpose of this study is to contribute to the literature by studying the effects of sudden changes both on crude oil import price and domestic gasoline price on inflation for Turkey, an emerging country. Since an inflation targeting regime is being carried out by the Central Bank of Turkey, determination of such effects is becoming more important. Therefore empirical evidence in this paper will serve as guidance for those countries, which have an in- flation targeting regime. Analyses have been done in the period of October 2005-December 2012 by Markovswitching vector autoregressive (MS-VAR) models which are successful in capturing the nonlinear properties of variables. Using MS-VAR analysis, it is found that there are 2 regimes in the analysis period. Furthermore, regime changes can be dated and the turning points of economic cycles can be determined. In addition, it is found that the effect of the changes in crude oil and domestic gasoline prices on consumer prices and core inflation is not the same under different regimes. Moreover, the sudden increase in gasoline price is more important for consumer price infla- tion than crude oil price shocks. Another finding is the presence of a pass-through effect from oil price and ga- soline price to core inflation.
基金The author is infinitely thankful to his friend and colleague M.Rubinstein for valuable discussions and an invariable interest to his work.The author is also thankful to C.Miller for his high estimation of the author’s efforts.Of course,all errors are author’s full responsibility.
文摘We use Extended Merton model(EMM)for estimating the firm’s credit risks in the presence of inflation.We show quantitatively that inflation is an influential factor making either a benign or adverse effect on the firm’s survival,supporting at the microeconomic level New Keynesian findings of the nonlinear inflation effect on output growth.Lower inflation increasing the firm’s expected rate of return can raise its mean year returns and decrease its default probability.Higher inflation,decreasing the expected rate return,makes the opposite effect.The magnitude of the adverse effect depends on the firm strength:for a steady firm,this effect is small,whereas for a weaker firm,it can be fatal.EMM is the only model taking account of inflation.It can be useful for banks or insurance companies estimating credit risks of commercial borrowers over the debt maturity,and for the firm’s management planning long-term business operations.
文摘In this paper, the Holt’s exponential smoothing and Auto-Regressive Integrated Moving Average (ARIMA) models were used to forecast inflation rate of Zambia using the monthly consumer price index (CPI) data from May 2010 to May 2014. Results show that the ARIMA ((12), 1, 0) is an adequate model which best fits the CPI time series data and is therefore suitable for forecasting CPI and subsequently the inflation rate. However, the choice of the Holt’s exponential smoothing is as good as an ARIMA model considering the smaller deviations in the mean absolute percentage error and mean square error. Moreover, the Holt’s exponential smoothing model is less complicated since you do not require specialised software to implement it as is the case for ARIMA models. The forecasted inflation rate for April and May, 2015 is 7.0 and 6.6 respectively.
文摘We were interested, along this work, in the phenomena of the quintessence and the inflation due to the F-harmonic maps, in other words, in the functions of the scalar field such as the exponential and trigo-harmonic maps. We showed that some F-harmonic map such as the trigonometric functions instead of the scalar field in the lagrangian, allow, in the absence of term of potential, reproduce the inflation. However, there are other F-harmonic maps such as exponential maps which can’t produce the inflation;the pressure and the density of this exponential harmonic field being both of the same sign. On the other hand, these exponential harmonic fields redraw well the phenomenon of the quintessence when the variation of these fields remains weak. The problem of coincidence, however remains.
文摘Since July 2010,the prices of geographical indication products have risen with the occurrence of inflation.In contrast with other products,geographical indication products are distinct.The increasing prices of geographical indication goods have their own necessities.From the perspective of the products,they are equipped with appreciation potential due to the cultural pe culiarities.From the historical standpoint,their prices have not been high as well as other agricultural products.Realistically,the increase in their prices results from the costs of labors and raw materials.Therefore,the prices of geographical indication products rise to catch up.Not only are their prices at a reasonable level,but also they are beneficial to increase peasants'income.In con clusion,it is necessary that the strategies which are different from those of other products be adopted to regulate and control the prices of geographical indication products.
文摘The early universe inflation is well known as a promising theory to explain the origin of large-scale structure of universe and to solve the early universe pressing problems. For a reasonable inflation model, the potential during inflation must be very flat, at least, in the direction of the inflaton. To construct the inflaton potential all the known related astrophysics observations should be included. For a general tree-level hybrid inflation potential, which is notdiscussed fully so far, the parameters in it are shown how to be constrained via the astrophysics data observed and to be obtained to the expected accuracy, and to be consistent with cosmology requirements.
基金Kourosh Nozari is supported financially by the Science and Research Branch,Islamic Azad university,Mazandaran,Iran
文摘We construct a general braneworld inflation scenario where the inflaton field evolves on the DGP brahe and curvature effects are taken into account via incorporation of the Gauss-Bonnet term in the bulk action. While induced gravity on the DGP brane modifies the IR limit of general relativity, the Gauss-Bonnet term in the bulk action modifies the UV sector of the theory. In this setup, the dynamics of perturbations on the brane are studied with details and some confrontation with recent observations are discussed. While the Einstein-Gauss-Bonnet inflation scenario favors only a red spectrum of the scalar perturbation, pure DGP and GBIG inflation models have the capacity to realize the blue spectrum too. In addition, the GBIG inflation scenario in the large field limit requires a smaller number of e-folds than other proposed scenarios in the same situation. For the tensor-to-scalar ratio, the GBIG inflation scenario g/yes a better fit with observationally supported value of R≈ 0.24.
基金Project supported by the National Natural Science Foundation of China (Grant No 10773008)
文摘This paper presents a new exact inflationary solution to the non-minimMly coupled scalar field. The inflation is driven by the evolution of a scalar field with inflation potential V(φ) = (λ/4)φ4 + b1φ2 + b2 + b3φ-2 + b4φ-4. The spectral index of the scalar density fluctuations ns is consistent with the result of WMAP3 (Wilkinson Microwave Anisotropy Probe 3) for ACDM (Lambda-Cold Dark Matter). This model relaxes the constraint to the quartic coupling constant. And it can enter smoothly into a radiation-dominated stage when inflation ends.