This paper investigates complex brackets and balanced complex 1st-order difference (BCD) polynomials. Then we propose an algorithm of O(n log n) complexity to check the equality of brackets. It substitutes exponential...This paper investigates complex brackets and balanced complex 1st-order difference (BCD) polynomials. Then we propose an algorithm of O(n log n) complexity to check the equality of brackets. It substitutes exponential algorithms before. Also, BCD polynomials have some usages in geometric calculation.展开更多
We investigate a generalized form of the Boussinesq equation, relevant for nerve pulse propagation in biological membranes. The generalized conditional symmetry （GCS） method is applied in order to obtain the conditi...We investigate a generalized form of the Boussinesq equation, relevant for nerve pulse propagation in biological membranes. The generalized conditional symmetry （GCS） method is applied in order to obtain the conditions that enable the equation to admit a special class of second-order GCSs. For the case of quadratic nonlinearities, we outline a new class of invariant solutions.展开更多
The cyclic transformation behaviors of polycrystalline super-elastic NiTi shape memory alloys (SMAs)under multiaxial loading paths with different angles between axial and torsional loading orientations were experiment...The cyclic transformation behaviors of polycrystalline super-elastic NiTi shape memory alloys (SMAs)under multiaxial loading paths with different angles between axial and torsional loading orientations were experimentally investigated.The experimental results showed that the start stresses of forward and reverse transformations decreased with the increase'in the number of cycles and exhibit obvious anisotropic evolutions.The start stresses of forward and reverse transformations in the tensile and torsional directions did not satisfy the yon Mises criterion.The shape of transformation surface during the forward and reverse transformations evolved with the increase in the number of cycles.Then,new cyclic anisotropic transformation surfaces were established by introducing an anisotropic tensor into the von Mises equivalent stress based on a typical transformation criterion related to J2 and J3.Moreover,the evolution equations of material parameters used in the proposed transformation surfaces were established to describe the subsequent evolutions of transformation surfaces.Finally,the start stresses of forward and reverse transformations predicted using the proposed transformation surfaces were compared with the experimental results.It shows that the proposed transformation surfaces can reasonably describe the start stresses of forward and reverse transformations,which are helpful for establishing a three-dimensional cyclic constitutive model to describe the cyclic transformation behaviors of super-elastic NiTi SMAs.展开更多
针对UAV(Unmanned Aerial Vehicle)侦察目标识别中的实时性和鲁棒性的要求,提出一种基于SURF(Speeded Up Robust Features)的快速目标识别算法。对UAV侦察图像进行预处理,采用不变矩构造遗传算法的适应度函数,利用遗传算法的全局搜索能...针对UAV(Unmanned Aerial Vehicle)侦察目标识别中的实时性和鲁棒性的要求,提出一种基于SURF(Speeded Up Robust Features)的快速目标识别算法。对UAV侦察图像进行预处理,采用不变矩构造遗传算法的适应度函数,利用遗传算法的全局搜索能力快速地提取可能包含目标的RO(IRegion Of Interesting)区域。在ROI区域和模板图像中提取SURF特征点,采用最近邻的匹配算法搜索匹配对,从而精确确定目标的位置。仿真结果显示,该算法可以明显地提高目标识别的实时性并具有相当的鲁棒性。展开更多
Poschl-Teller double-ring-shaped Coulomb （PTDRSC） potential, the Coulomb potential surrounded by PSschl- Teller and double-ring-shaped inversed square potential, is put forward. In spherical polar coordinates, PTDRS...Poschl-Teller double-ring-shaped Coulomb （PTDRSC） potential, the Coulomb potential surrounded by PSschl- Teller and double-ring-shaped inversed square potential, is put forward. In spherical polar coordinates, PTDRSC potential has supersymmetry and shape invariance in φ,θ and τ coordinates. By using the method of supersymmetry and shape invariance, exact bound state solutions of Schr6dinger equation with PTDRSC potential are presented. The normalized φ,θ angular wave function expressed in terms of Jacobi polynomials and the normalized radial wave function expressed in terms of Laguerre polynomials are presented. Energy spectrum equations are obtained. Wave function and energy spectrum equations of the system are related to three quantum numbers and parameters of PTDRSC potential. The solutions of wave functions and corresponding eigenvalues are only suitable for the PTDRSC potential.展开更多
基金supported by the National Key Basic Research Project of China (Grant No. 2004CB318001)
文摘This paper investigates complex brackets and balanced complex 1st-order difference (BCD) polynomials. Then we propose an algorithm of O(n log n) complexity to check the equality of brackets. It substitutes exponential algorithms before. Also, BCD polynomials have some usages in geometric calculation.
文摘We investigate a generalized form of the Boussinesq equation, relevant for nerve pulse propagation in biological membranes. The generalized conditional symmetry （GCS） method is applied in order to obtain the conditions that enable the equation to admit a special class of second-order GCSs. For the case of quadratic nonlinearities, we outline a new class of invariant solutions.
基金National Natural Science Foundation of China (1157226511532010),the Excellent Youth Found of Sichuan Province (2017JQ0019),the Open Project of Traction Power State Key Laboratory (TPL1606)and the Exploration Project of Traction Power State Key Laboratory (2017TPL_T04)are acknowledged.
文摘The cyclic transformation behaviors of polycrystalline super-elastic NiTi shape memory alloys (SMAs)under multiaxial loading paths with different angles between axial and torsional loading orientations were experimentally investigated.The experimental results showed that the start stresses of forward and reverse transformations decreased with the increase'in the number of cycles and exhibit obvious anisotropic evolutions.The start stresses of forward and reverse transformations in the tensile and torsional directions did not satisfy the yon Mises criterion.The shape of transformation surface during the forward and reverse transformations evolved with the increase in the number of cycles.Then,new cyclic anisotropic transformation surfaces were established by introducing an anisotropic tensor into the von Mises equivalent stress based on a typical transformation criterion related to J2 and J3.Moreover,the evolution equations of material parameters used in the proposed transformation surfaces were established to describe the subsequent evolutions of transformation surfaces.Finally,the start stresses of forward and reverse transformations predicted using the proposed transformation surfaces were compared with the experimental results.It shows that the proposed transformation surfaces can reasonably describe the start stresses of forward and reverse transformations,which are helpful for establishing a three-dimensional cyclic constitutive model to describe the cyclic transformation behaviors of super-elastic NiTi SMAs.
文摘针对UAV(Unmanned Aerial Vehicle)侦察目标识别中的实时性和鲁棒性的要求,提出一种基于SURF(Speeded Up Robust Features)的快速目标识别算法。对UAV侦察图像进行预处理,采用不变矩构造遗传算法的适应度函数,利用遗传算法的全局搜索能力快速地提取可能包含目标的RO(IRegion Of Interesting)区域。在ROI区域和模板图像中提取SURF特征点,采用最近邻的匹配算法搜索匹配对,从而精确确定目标的位置。仿真结果显示,该算法可以明显地提高目标识别的实时性并具有相当的鲁棒性。
基金Project supported by the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province of China (Grant No. 05KJD140252)the Natural Science Foundation of Jiangsu Province of China (Grant No. KB2008199)
文摘Poschl-Teller double-ring-shaped Coulomb （PTDRSC） potential, the Coulomb potential surrounded by PSschl- Teller and double-ring-shaped inversed square potential, is put forward. In spherical polar coordinates, PTDRSC potential has supersymmetry and shape invariance in φ,θ and τ coordinates. By using the method of supersymmetry and shape invariance, exact bound state solutions of Schr6dinger equation with PTDRSC potential are presented. The normalized φ,θ angular wave function expressed in terms of Jacobi polynomials and the normalized radial wave function expressed in terms of Laguerre polynomials are presented. Energy spectrum equations are obtained. Wave function and energy spectrum equations of the system are related to three quantum numbers and parameters of PTDRSC potential. The solutions of wave functions and corresponding eigenvalues are only suitable for the PTDRSC potential.
