卫星振动不仅会引起TDI(Time Delay and Integration)CCD相机像元采样的不规则性,还会引起像元弥散斑空间分布的不一致性,导致图像传递函数(Modulation Transfer Function,MTF)产生空间变化,从而制约高分辨率图像振动复原质量。本文从...卫星振动不仅会引起TDI(Time Delay and Integration)CCD相机像元采样的不规则性,还会引起像元弥散斑空间分布的不一致性,导致图像传递函数(Modulation Transfer Function,MTF)产生空间变化,从而制约高分辨率图像振动复原质量。本文从卫星振动对TDICCD相机推扫成像采样过程的作用机理出发,结合理论推导与仿真研究,得到了平台振动引起的图像空间移变降质及表征方法。然后在振动复原模型的基础上,推导得出MTF空间移变降质对复原处理误差的影响,并基于实际卫星图像开展了复原实验。实验结果表明:当振动所致图像MTF空间移变降质小于15%时,复原处理后的图像与理想图像的结构相似度优于0.95,而且处理误差所导致的图像失真不影响判读质量。展开更多
The policy of land transfer has greatly influenced the macro economy of China with the commencement of another innovation of land use system. Therefore, it is urgent to put forward some rational and feasible suggestio...The policy of land transfer has greatly influenced the macro economy of China with the commencement of another innovation of land use system. Therefore, it is urgent to put forward some rational and feasible suggestions for local government to manage the market of land transfer. Moreover, it is important in the field of study on agricultural land use change to analyze the spatial differentiation and structural specification of land transfer, which are caused by rural households＇ behavior. This paper selected I l factors covering four aspects of rural households＇ family structure, family location, family income structure and the natural quality of land resources, all of which influence the behavior differentiation of rural households, to establish the index model indicating spatial differentiation of land transfer. Results show that the spatial differentiation of land transfer can be divided into four degrees and three categories through analyzing rural households＇ questionnaires from Shanghai, Nanjing and Taizhou in the Changjiang （Yangtze） River Delta. Since up to 80% of rural households belong to middle degrees, it can be concluded that the rural land market develops evenly in the study areas. And it is also indicated that the natural quality of land resources and the maximum income of rural land are most important factors influencing the spatial differentiation of land transaction. Considering different factors, the countermeasures can be carried out to enhance the spatial differentiation of land transfer so as to promote economic development and social security of rural China. All in all, both micro- factors and macro-factors influencing rural households＇ behavior of rural land transfer should be taken into account in order to make spatial differentiation and structural specification of rural land transfer notable.展开更多
We show asymmetric multi-channel sampling on a series of a shift invariant spaces ∑a^m=1v（φ（ta）） with a series of Riesz generators ∑a^m=1φ（ta） in L2（R）, where each channeled signal is assigned a uniform bu...We show asymmetric multi-channel sampling on a series of a shift invariant spaces ∑a^m=1v（φ（ta）） with a series of Riesz generators ∑a^m=1φ（ta） in L2（R）, where each channeled signal is assigned a uniform but distinct sampling rate. We use Fourier duality between ∑a^m=1v（φ（ta））and L2[0, 2π] to find conditions under which there is a stable asymmetric multi-channel sampling formula on ∑a^m=1v（φ（ta））.展开更多
CART(Constituent-oriented age and residence time theory) and PTM(Particle-tracking method) are two widely used numerical methods to calculate water age. These two methods are essentially equivalent in theory but their...CART(Constituent-oriented age and residence time theory) and PTM(Particle-tracking method) are two widely used numerical methods to calculate water age. These two methods are essentially equivalent in theory but their results may be different in practice. The difference of the two methods was evaluated by applying them to calculate water age in an idealized one-dimensional domain. The model results by the two methods are consistent with each other in the case with either spatially uniform flow field or spatially uniform diffusion coefficient. If we allow the spatial variation in horizontal diffusion, a term called pseudo displacement arising from the spatial variation of diffusion coefficient likely plays an important role for the PTM to obtain accurate water age. In particular, if the water particle is released at a place where the diffusion is not the weakest, the water age calculated by the PTM without pseudo displacement is much larger than that by the CART. This suggests that the pseudo displacement cannot be neglected in the PTM to calculate water age in a realistic ocean. As an example, we present its potential importance in the Bohai Sea where the diffusion coefficient varies spatially and greatly.展开更多
Starting from the basic equation of elastic mechanics, without any additional hypotheses of displacement or stress model, just introducing state space and state equation, the model of rock strata movement as complex l...Starting from the basic equation of elastic mechanics, without any additional hypotheses of displacement or stress model, just introducing state space and state equation, the model of rock strata movement as complex laminated plates is presented. In addition, using displacement as a basic unknown quantity, the accurate analytical series solution for the problem of strata movement induced by extraction of horizontal seam is worked out when crosswise isotropic elastic layers are in sliding contact condition. A new approach is put forward to solve the complicated system of mining subsidence.展开更多
In this paper, the author at first develops a method to study convergence of the cascadealgorithm in a Banach space without stable assumption on the initial (see Theorem 2.1), andthen applies the previous result on th...In this paper, the author at first develops a method to study convergence of the cascadealgorithm in a Banach space without stable assumption on the initial (see Theorem 2.1), andthen applies the previous result on the convergence to characterizing compactly supportedrefinable distributions in fractional Sobolev spaces and Holder continuous spaces (see Theorems3.1, 3.3, and 3.4). Finally the author applies the above characterization to choosing appropriateinitial to guarantee the convergence of the cascade algorithm (see Theorem 4.2).展开更多
Continuous, SL(n) and translation invariant real-valued valuations on Sobolev spaces are classified.The centro-affine Hadwiger's theorem is applied. In the homogeneous case, these valuations turn out to be L^p-nor...Continuous, SL(n) and translation invariant real-valued valuations on Sobolev spaces are classified.The centro-affine Hadwiger's theorem is applied. In the homogeneous case, these valuations turn out to be L^p-norms raised to p-th power(up to suitable multipication scales).展开更多
文摘卫星振动不仅会引起TDI(Time Delay and Integration)CCD相机像元采样的不规则性,还会引起像元弥散斑空间分布的不一致性,导致图像传递函数(Modulation Transfer Function,MTF)产生空间变化,从而制约高分辨率图像振动复原质量。本文从卫星振动对TDICCD相机推扫成像采样过程的作用机理出发,结合理论推导与仿真研究,得到了平台振动引起的图像空间移变降质及表征方法。然后在振动复原模型的基础上,推导得出MTF空间移变降质对复原处理误差的影响,并基于实际卫星图像开展了复原实验。实验结果表明:当振动所致图像MTF空间移变降质小于15%时,复原处理后的图像与理想图像的结构相似度优于0.95,而且处理误差所导致的图像失真不影响判读质量。
基金Under the auspices of the National Natural Science Foundation of China (No. 70373029)
文摘The policy of land transfer has greatly influenced the macro economy of China with the commencement of another innovation of land use system. Therefore, it is urgent to put forward some rational and feasible suggestions for local government to manage the market of land transfer. Moreover, it is important in the field of study on agricultural land use change to analyze the spatial differentiation and structural specification of land transfer, which are caused by rural households＇ behavior. This paper selected I l factors covering four aspects of rural households＇ family structure, family location, family income structure and the natural quality of land resources, all of which influence the behavior differentiation of rural households, to establish the index model indicating spatial differentiation of land transfer. Results show that the spatial differentiation of land transfer can be divided into four degrees and three categories through analyzing rural households＇ questionnaires from Shanghai, Nanjing and Taizhou in the Changjiang （Yangtze） River Delta. Since up to 80% of rural households belong to middle degrees, it can be concluded that the rural land market develops evenly in the study areas. And it is also indicated that the natural quality of land resources and the maximum income of rural land are most important factors influencing the spatial differentiation of land transaction. Considering different factors, the countermeasures can be carried out to enhance the spatial differentiation of land transfer so as to promote economic development and social security of rural China. All in all, both micro- factors and macro-factors influencing rural households＇ behavior of rural land transfer should be taken into account in order to make spatial differentiation and structural specification of rural land transfer notable.
文摘We show asymmetric multi-channel sampling on a series of a shift invariant spaces ∑a^m=1v（φ（ta）） with a series of Riesz generators ∑a^m=1φ（ta） in L2（R）, where each channeled signal is assigned a uniform but distinct sampling rate. We use Fourier duality between ∑a^m=1v（φ（ta））and L2[0, 2π] to find conditions under which there is a stable asymmetric multi-channel sampling formula on ∑a^m=1v（φ（ta））.
基金funded by the National Natural Science Foundation of China (Nos. 41176007 and 40706007)
文摘CART(Constituent-oriented age and residence time theory) and PTM(Particle-tracking method) are two widely used numerical methods to calculate water age. These two methods are essentially equivalent in theory but their results may be different in practice. The difference of the two methods was evaluated by applying them to calculate water age in an idealized one-dimensional domain. The model results by the two methods are consistent with each other in the case with either spatially uniform flow field or spatially uniform diffusion coefficient. If we allow the spatial variation in horizontal diffusion, a term called pseudo displacement arising from the spatial variation of diffusion coefficient likely plays an important role for the PTM to obtain accurate water age. In particular, if the water particle is released at a place where the diffusion is not the weakest, the water age calculated by the PTM without pseudo displacement is much larger than that by the CART. This suggests that the pseudo displacement cannot be neglected in the PTM to calculate water age in a realistic ocean. As an example, we present its potential importance in the Bohai Sea where the diffusion coefficient varies spatially and greatly.
文摘Starting from the basic equation of elastic mechanics, without any additional hypotheses of displacement or stress model, just introducing state space and state equation, the model of rock strata movement as complex laminated plates is presented. In addition, using displacement as a basic unknown quantity, the accurate analytical series solution for the problem of strata movement induced by extraction of horizontal seam is worked out when crosswise isotropic elastic layers are in sliding contact condition. A new approach is put forward to solve the complicated system of mining subsidence.
文摘In this paper, the author at first develops a method to study convergence of the cascadealgorithm in a Banach space without stable assumption on the initial (see Theorem 2.1), andthen applies the previous result on the convergence to characterizing compactly supportedrefinable distributions in fractional Sobolev spaces and Holder continuous spaces (see Theorems3.1, 3.3, and 3.4). Finally the author applies the above characterization to choosing appropriateinitial to guarantee the convergence of the cascade algorithm (see Theorem 4.2).
基金supported by Austrian Science Fund Project(Grant No.P23639-N18)National Natural Science Foundation of China(Grant No.11371239)
文摘Continuous, SL(n) and translation invariant real-valued valuations on Sobolev spaces are classified.The centro-affine Hadwiger's theorem is applied. In the homogeneous case, these valuations turn out to be L^p-norms raised to p-th power(up to suitable multipication scales).
