With the development of economy, architectural design begins to be close- ly integrated with environment and culture. It is characterized by ecological energy saving, graceful modeling, harmony of view and landscape a...With the development of economy, architectural design begins to be close- ly integrated with environment and culture. It is characterized by ecological energy saving, graceful modeling, harmony of view and landscape and so on. In the past, the phenomenon of isolation between landscape architecture major and architectural design specialty has become less and less, and the architectural design integrating the theory and method of architecture, planning and landscape design makes them complement each other and support each other. Based on the perspective of the humanities, expounds the similarities and differences between landscape architecture and landscape architecture, and carries on the comparative analysis to the two from the composition, types and characteristics of the angle, achieve the greatest degree of harmony and unity of architecture and landscape environment, to create the most complete system, it will be the development trend of architectural and landscape de- sign.展开更多
Time-series Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data have been widely used for large area crop mapping.However,the temporal crop signatures generated fro...Time-series Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data have been widely used for large area crop mapping.However,the temporal crop signatures generated from these data were always accompanied by noise.In this study,a denoising method combined with Time series Inverse Distance Weighted (T-IDW) interpolating and Discrete Wavelet Transform (DWT) was presented.The detail crop planting patterns in Hebei Plain,China were classified using denoised time-series MODIS NDVI data at 250 m resolution.The denoising approach improved original MODIS NDVI product significantly in several periods,which may affect the accuracy of classification.The MODIS NDVI-derived crop map of the Hebei Plain achieved satisfactory classification accuracies through validation with field observation,statistical data and high resolution image.The field investigation accuracy was 85% at pixel level.At county-level,for winter wheat,there is relatively more significant correlation between the estimated area derived from satellite data with noise reduction and the statistical area (R2 = 0.814,p < 0.01).Moreover,the MODIS-derived crop patterns were highly consistent with the map generated by high resolution Landsat image in the same period.The overall accuracy achieved 91.01%.The results indicate that the method combining T-IDW and DWT can provide a gain in time-series MODIS NDVI data noise reduction and crop classification.展开更多
Nonlinear Schrodinger equation (NSE) arises in many physical problems. It is a very important equation. A lot of works studied the wellposed, the existence of solution of NSE etc. And there are many works studied the ...Nonlinear Schrodinger equation (NSE) arises in many physical problems. It is a very important equation. A lot of works studied the wellposed, the existence of solution of NSE etc. And there are many works studied the numerical methods for it. Recently, since the development of infinite dimensional dynamic system the dynamical behavior of NSE has been investigated. The paper [1] studied the long time wellposedness, the existence of universal attractor and the estimate of Lyapunov exponent for NSE with weakly damped. At the same time it was need to study the large time new computational methods and to discuss its convergence error estimate, the existence of approximate attractors etc. In this pape we study the NSE with weakly damped (1.1). We assume,where 0【λ【2 is a constant. If we wish to construct the higher accuracy computational scheme, it will be difficult that staigh from the equation (1.1). Therefore we start with (1. 4) and use fully discrete Fourier spectral method with time difference to展开更多
An experiment is carried out on the surface oscillation of buoyant-thermocapillary convection in an open cylindrical annulus. When the radial temperature difference AT reaches a critical value △Tc, a regular oscillat...An experiment is carried out on the surface oscillation of buoyant-thermocapillary convection in an open cylindrical annulus. When the radial temperature difference AT reaches a critical value △Tc, a regular oscillation appears and soon disappears on the open surface, which varies when the liquid layer＇s thickness h and temperature difference △T are varied. With growth of △T, dominant frequency of the visible oscillation will grow too but is found within certain frequencies. Driving forces, buoyance and thermocapillarity, are responsible for this phenomanon and the ＂balance＂ point is considered to exist when h is between 4.5-5.0 mm. Surface oscillation region is also found restricted within a narrow gap when Bo is smaller than 3.7.展开更多
Chaotic vibrations of flexible non-linear Euler-Bernoulli beams subjected to harmonic load and with various boundary conditions（symmetric and non-symmetric）are studied in this work.Reliability of the obtained result...Chaotic vibrations of flexible non-linear Euler-Bernoulli beams subjected to harmonic load and with various boundary conditions（symmetric and non-symmetric）are studied in this work.Reliability of the obtained results is verified by the finite difference method（FDM）and the finite element method（FEM）with the Bubnov-Galerkin approximation for various boundary conditions and various dynamic regimes（regular and non-regular）.The influence of boundary conditions on the Euler-Bernoulli beams dynamics is studied mainly,dynamic behavior vs.control parameters { ωp,q0 } is reported,and scenarios of the system transition into chaos are illustrated.展开更多
Since the 1990s, the large-scale migrant labor force from rural to urban areas has made great contributions to the growth in China. However, migration does not come without costs. The potential impacts of parental mig...Since the 1990s, the large-scale migrant labor force from rural to urban areas has made great contributions to the growth in China. However, migration does not come without costs. The potential impacts of parental migration on the left-behind children have aroused wide concerns. Based on a two-wave panel dataset of nearly 10 thousand students in 166 schools from 13 counties in 5 provinces between 2014 and 2015, differences-in-differences （DID） and propensity score matching plus DID （PSMDID） approaches were used to examine the changes in academic performances before and after the parental out-migration. The results indicated that the mother only migration has a significant negative impact on the a- cademic performances of left-behind children, and it was especially true when the mother only migration lasted more than a semester. For left-behind children whose parents were out or only the father was out, their academic performances were not affected.展开更多
A four-body distorted wave approximation is presented for theoretical investigations of the single ionization of groundstate helium atoms by fully stripped carbon ions at impact energies of 2 MeV/amu and 100 MeV/amu. ...A four-body distorted wave approximation is presented for theoretical investigations of the single ionization of groundstate helium atoms by fully stripped carbon ions at impact energies of 2 MeV/amu and 100 MeV/amu. The nine-dimensional integrals for the partial quantum-mechanical transition amplitudes of the specified reaction are reduced to some analytical expressions or one-dimensional integrals over real variables. Fully differential cross sections（FDCSs） are calculated and compared with their experimental values as well as the results obtained from other theories. Despite the simplicity and quickness of the proposed quadrature, the comparison shows that the obtained results are in reasonable agreement with the experiment and are compatible with those of other complicated theories.展开更多
In this paper, we summarize 3D perception-oriented algorithms for perceptually driven 3D video coding. Several perceptual ef- fects have been exploited for 2D video viewing; however, this is not yet the case for 3D vi...In this paper, we summarize 3D perception-oriented algorithms for perceptually driven 3D video coding. Several perceptual ef- fects have been exploited for 2D video viewing; however, this is not yet the case for 3D video viewing. 3D video requires depth perception, which implies binocular effects such as con fl icts, fusion, and rivalry. A better understanding of these effects is necessary for 3D perceptual compression, which provides users with a more comfortable visual experience for video that is de- livered over a channel with limited bandwidth. We present state-of-the-art of 3D visual attention models, 3D just-notice- able difference models, and 3D texture-synthesis models that address 3D human vision issues in 3D video coding and trans-mission.展开更多
Several numerical experiments were performed to investigate the dynamic and thermodynamic effects of sea surface temperature （SST） on tropical cyclone （TC） intensity. The results reveal that the relative SST withi...Several numerical experiments were performed to investigate the dynamic and thermodynamic effects of sea surface temperature （SST） on tropical cyclone （TC） intensity. The results reveal that the relative SST within a radius of 2-3 times the radius of maximum wind contributes positively and greatly to TC intensity, while the remote SST far away from the TC center could reduce storm intensity. The change of air sea temperature and moisture differences may be the reason why TC intensity is more sensitive to the relative rather than the absolute SST. As the inflow air moves toward the eyewall, warmer （colder） remote SST can gradually increase （decrease） the underlying surface air temperature and moisture, and thus decrease （increase） the air sea temperature and moisture differences, which lead to less （more） energy fluxes entering the eyewall and then decrease （increase） the TC intensity and make it less sensitive to the absolute SST change. Finally, with all the related dynamic and thermodynamic processes being taken into account, a schematic diagram for the effects of relative SST and absolute SST on TC intensity is proposed.展开更多
In this paper, we consider the solution of the following rational systems of difference equations：xn＋1=zn-1xn-2/xn-2±yn,yn＋1=xn-1yn-2/yn-2±zn,zn＋1=yn-1zn-2/zn-1±xn,where initial conditions are nonze...In this paper, we consider the solution of the following rational systems of difference equations：xn＋1=zn-1xn-2/xn-2±yn,yn＋1=xn-1yn-2/yn-2±zn,zn＋1=yn-1zn-2/zn-1±xn,where initial conditions are nonzero real numbers.展开更多
文摘With the development of economy, architectural design begins to be close- ly integrated with environment and culture. It is characterized by ecological energy saving, graceful modeling, harmony of view and landscape and so on. In the past, the phenomenon of isolation between landscape architecture major and architectural design specialty has become less and less, and the architectural design integrating the theory and method of architecture, planning and landscape design makes them complement each other and support each other. Based on the perspective of the humanities, expounds the similarities and differences between landscape architecture and landscape architecture, and carries on the comparative analysis to the two from the composition, types and characteristics of the angle, achieve the greatest degree of harmony and unity of architecture and landscape environment, to create the most complete system, it will be the development trend of architectural and landscape de- sign.
基金Under the auspices of Knowledge Innovation Programs of Chinese Academy of Sciences (No.KZCX2-YW-449,KSCX-YW-09)National Natural Science Foundation of China (No.40971025,40901030,50969003)
文摘Time-series Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data have been widely used for large area crop mapping.However,the temporal crop signatures generated from these data were always accompanied by noise.In this study,a denoising method combined with Time series Inverse Distance Weighted (T-IDW) interpolating and Discrete Wavelet Transform (DWT) was presented.The detail crop planting patterns in Hebei Plain,China were classified using denoised time-series MODIS NDVI data at 250 m resolution.The denoising approach improved original MODIS NDVI product significantly in several periods,which may affect the accuracy of classification.The MODIS NDVI-derived crop map of the Hebei Plain achieved satisfactory classification accuracies through validation with field observation,statistical data and high resolution image.The field investigation accuracy was 85% at pixel level.At county-level,for winter wheat,there is relatively more significant correlation between the estimated area derived from satellite data with noise reduction and the statistical area (R2 = 0.814,p < 0.01).Moreover,the MODIS-derived crop patterns were highly consistent with the map generated by high resolution Landsat image in the same period.The overall accuracy achieved 91.01%.The results indicate that the method combining T-IDW and DWT can provide a gain in time-series MODIS NDVI data noise reduction and crop classification.
文摘Nonlinear Schrodinger equation (NSE) arises in many physical problems. It is a very important equation. A lot of works studied the wellposed, the existence of solution of NSE etc. And there are many works studied the numerical methods for it. Recently, since the development of infinite dimensional dynamic system the dynamical behavior of NSE has been investigated. The paper [1] studied the long time wellposedness, the existence of universal attractor and the estimate of Lyapunov exponent for NSE with weakly damped. At the same time it was need to study the large time new computational methods and to discuss its convergence error estimate, the existence of approximate attractors etc. In this pape we study the NSE with weakly damped (1.1). We assume,where 0【λ【2 is a constant. If we wish to construct the higher accuracy computational scheme, it will be difficult that staigh from the equation (1.1). Therefore we start with (1. 4) and use fully discrete Fourier spectral method with time difference to
基金supported by the National Natural Science Foundation of China(11032011 and 10972224)Knowledge Innovation Program of Chinese Academy of Sciences(KJCX2-YW-L08)
文摘An experiment is carried out on the surface oscillation of buoyant-thermocapillary convection in an open cylindrical annulus. When the radial temperature difference AT reaches a critical value △Tc, a regular oscillation appears and soon disappears on the open surface, which varies when the liquid layer＇s thickness h and temperature difference △T are varied. With growth of △T, dominant frequency of the visible oscillation will grow too but is found within certain frequencies. Driving forces, buoyance and thermocapillarity, are responsible for this phenomanon and the ＂balance＂ point is considered to exist when h is between 4.5-5.0 mm. Surface oscillation region is also found restricted within a narrow gap when Bo is smaller than 3.7.
文摘Chaotic vibrations of flexible non-linear Euler-Bernoulli beams subjected to harmonic load and with various boundary conditions（symmetric and non-symmetric）are studied in this work.Reliability of the obtained results is verified by the finite difference method（FDM）and the finite element method（FEM）with the Bubnov-Galerkin approximation for various boundary conditions and various dynamic regimes（regular and non-regular）.The influence of boundary conditions on the Euler-Bernoulli beams dynamics is studied mainly,dynamic behavior vs.control parameters { ωp,q0 } is reported,and scenarios of the system transition into chaos are illustrated.
文摘Since the 1990s, the large-scale migrant labor force from rural to urban areas has made great contributions to the growth in China. However, migration does not come without costs. The potential impacts of parental migration on the left-behind children have aroused wide concerns. Based on a two-wave panel dataset of nearly 10 thousand students in 166 schools from 13 counties in 5 provinces between 2014 and 2015, differences-in-differences （DID） and propensity score matching plus DID （PSMDID） approaches were used to examine the changes in academic performances before and after the parental out-migration. The results indicated that the mother only migration has a significant negative impact on the a- cademic performances of left-behind children, and it was especially true when the mother only migration lasted more than a semester. For left-behind children whose parents were out or only the father was out, their academic performances were not affected.
基金the office of graduate studies at the University of Isfahan for their support and research facilities
文摘A four-body distorted wave approximation is presented for theoretical investigations of the single ionization of groundstate helium atoms by fully stripped carbon ions at impact energies of 2 MeV/amu and 100 MeV/amu. The nine-dimensional integrals for the partial quantum-mechanical transition amplitudes of the specified reaction are reduced to some analytical expressions or one-dimensional integrals over real variables. Fully differential cross sections（FDCSs） are calculated and compared with their experimental values as well as the results obtained from other theories. Despite the simplicity and quickness of the proposed quadrature, the comparison shows that the obtained results are in reasonable agreement with the experiment and are compatible with those of other complicated theories.
文摘In this paper, we summarize 3D perception-oriented algorithms for perceptually driven 3D video coding. Several perceptual ef- fects have been exploited for 2D video viewing; however, this is not yet the case for 3D video viewing. 3D video requires depth perception, which implies binocular effects such as con fl icts, fusion, and rivalry. A better understanding of these effects is necessary for 3D perceptual compression, which provides users with a more comfortable visual experience for video that is de- livered over a channel with limited bandwidth. We present state-of-the-art of 3D visual attention models, 3D just-notice- able difference models, and 3D texture-synthesis models that address 3D human vision issues in 3D video coding and trans-mission.
基金Supported by the National Natural Science Foundation of China(41175090 and 40830958)National High Technology Research and Development(863)Program of China(2012AA091801)
文摘Several numerical experiments were performed to investigate the dynamic and thermodynamic effects of sea surface temperature （SST） on tropical cyclone （TC） intensity. The results reveal that the relative SST within a radius of 2-3 times the radius of maximum wind contributes positively and greatly to TC intensity, while the remote SST far away from the TC center could reduce storm intensity. The change of air sea temperature and moisture differences may be the reason why TC intensity is more sensitive to the relative rather than the absolute SST. As the inflow air moves toward the eyewall, warmer （colder） remote SST can gradually increase （decrease） the underlying surface air temperature and moisture, and thus decrease （increase） the air sea temperature and moisture differences, which lead to less （more） energy fluxes entering the eyewall and then decrease （increase） the TC intensity and make it less sensitive to the absolute SST change. Finally, with all the related dynamic and thermodynamic processes being taken into account, a schematic diagram for the effects of relative SST and absolute SST on TC intensity is proposed.
文摘In this paper, we consider the solution of the following rational systems of difference equations：xn＋1=zn-1xn-2/xn-2±yn,yn＋1=xn-1yn-2/yn-2±zn,zn＋1=yn-1zn-2/zn-1±xn,where initial conditions are nonzero real numbers.
