基于留一准则的正交前向选择算法(Orthogonal Forward Selection based on Leave-One-Out Criteria,OFS-LOO)是最近提出的一种数据建模方法,它能够产生鲁棒性好的参数可调的核函数回归模型。OFS-LOO采用贪婪算法策略,利用全局优化算法...基于留一准则的正交前向选择算法(Orthogonal Forward Selection based on Leave-One-Out Criteria,OFS-LOO)是最近提出的一种数据建模方法,它能够产生鲁棒性好的参数可调的核函数回归模型。OFS-LOO采用贪婪算法策略,利用全局优化算法逐项调节每个回归项的参数,逐步地增加模型的项数,减少留一准则函数值。但是OFS-LOO仅保留当前最优解作为新回归项的参数,而忽略当前的选择对以后步骤的影响,破坏了模型的稀疏性。本文在OFS-LOO的框架下提出了一种新颖的树型算法。在选择核函数模型的每一项时,采用重复加权增进搜索(Repeated Weighted Boosting Search,RWBS)算法,同时保留RWBS得到的多个局部极值作为核函数参数的候选项。新方法试图找到传统OFS-LOO和全局最优解之间的折衷。实验表明,与传统方法相比,新方法得到的核函数模型稀疏性更好,泛化能力更强。展开更多
针对车辆跟踪过程中跟踪目标丢失或者失败的情况,提出一种改进型Camshift(Continuously Adaptive Mean Shift)算法和卡尔曼滤波相结合的跟踪方法。首先,利用卡尔曼滤波器实现跟踪目标的位置估计,以克服目标被遮挡造成的跟踪失败的问题,...针对车辆跟踪过程中跟踪目标丢失或者失败的情况,提出一种改进型Camshift(Continuously Adaptive Mean Shift)算法和卡尔曼滤波相结合的跟踪方法。首先,利用卡尔曼滤波器实现跟踪目标的位置估计,以克服目标被遮挡造成的跟踪失败的问题,然后再利用改进型Camshift算法依据目标距离搜索中心的位置,对H分量创建的颜色直方图中的每个像素位进行高斯模型核函数的加权处理,并自适应计算得到最优的搜索窗口,从而改善了传统Camshift不能直接抵制噪声干扰的缺点,解决了因跟踪目标在同色背景噪声干扰下出现的丢失问题。最后通过仿真实验表明:改进型Camshift算法和卡尔曼滤波的结合有效地提高了车辆跟踪的准确性和连续性。展开更多
The nucleon electromagnetic form factors are investigated within a simple diquark-quark model using the light-front formalism. In this model, baryon is described as a bound state of one quark and one clustering diquar...The nucleon electromagnetic form factors are investigated within a simple diquark-quark model using the light-front formalism. In this model, baryon is described as a bound state of one quark and one clustering diquark. The calculational results are compared with the experimental ones. We also regard the quarks in a baryon as pointlike constituent quarks.展开更多
The time-convolutionless （TCL） quantum master equation provides a powerful tool to simulate reduced dynanfics of a quantum system coupled to a bath. The key quantity ill the TCL master equation is the so-called kern...The time-convolutionless （TCL） quantum master equation provides a powerful tool to simulate reduced dynanfics of a quantum system coupled to a bath. The key quantity ill the TCL master equation is the so-called kernel or generator, which describes eflhcts of the bath degrees of freedom. Since the exact TCL generators are usually hard to calculate analytically, most applications of the TCL generalized master equation have relied on approximate generators using second and fourth order perturbative expansions. By using the hierarchical equation of motion （HEOM） and extended HEOM methods, we present a new approach to calculating the exact TCL generator and its high order perturbative expansions. The new approach is applied to the spin-boson model with diflhrent sets of parameters, to investigate the convergence of the high order expansiolls of the TCL generator. We also discuss circumstances where the exact TCL generator becomes singular for the spin-boson model, and a model of excitation energy transfer in the Fenna-Matthews-Olson complex.展开更多
We discuss the nucleon spin structure function g<SUB>1</SUB> and the difference between the proton and neutron targets , based on quark model calculation. Quark-hadron duality for the nucleon spin structur...We discuss the nucleon spin structure function g<SUB>1</SUB> and the difference between the proton and neutron targets , based on quark model calculation. Quark-hadron duality for the nucleon spin structure function is also analyzed. Effects of the Δ(1232) and Roper P<SUB>11</SUB>(1440) resonances on the spin structure function and on the difference are mentioned. The results of different models for the Roper resonance are also addressed.展开更多
We develop a simple analytic calculation for the first order wave function of helium in a model in which nuclear charge screening is caused by repulsive coulomb interaction. The perturbation term, first-order correlat...We develop a simple analytic calculation for the first order wave function of helium in a model in which nuclear charge screening is caused by repulsive coulomb interaction. The perturbation term, first-order correlation energy, and first-order wave function are divided into two components, one component associated with the repulsive coulomb interaction and the other proportional to magnetic shielding. The resulting first-order wave functions are applied to calculate second-order energies within the model. We find that the second-order energies are independent of the nuclear charge screening constant in the unperturbed Hamiltonian with a central coulomb potential.展开更多
This paper put forward the super-resolution image algorithm based on Gauss process regression sparse solution. We establish local Gauss process regression model, to solve the feasibility problem of regression super-re...This paper put forward the super-resolution image algorithm based on Gauss process regression sparse solution. We establish local Gauss process regression model, to solve the feasibility problem of regression super-resolution problem in solving Gauss process; further use sparse algorithm, not only it can optimize the super parameter of Gauss kernel function, but also to optimize the initial entry training, so as to obtain more accurate regression Gauss process. Experimental results show that： the paper proposed algorithm can does not reduce the image reconstruction results, and it can reduce the computational complexity.展开更多
文摘基于留一准则的正交前向选择算法(Orthogonal Forward Selection based on Leave-One-Out Criteria,OFS-LOO)是最近提出的一种数据建模方法,它能够产生鲁棒性好的参数可调的核函数回归模型。OFS-LOO采用贪婪算法策略,利用全局优化算法逐项调节每个回归项的参数,逐步地增加模型的项数,减少留一准则函数值。但是OFS-LOO仅保留当前最优解作为新回归项的参数,而忽略当前的选择对以后步骤的影响,破坏了模型的稀疏性。本文在OFS-LOO的框架下提出了一种新颖的树型算法。在选择核函数模型的每一项时,采用重复加权增进搜索(Repeated Weighted Boosting Search,RWBS)算法,同时保留RWBS得到的多个局部极值作为核函数参数的候选项。新方法试图找到传统OFS-LOO和全局最优解之间的折衷。实验表明,与传统方法相比,新方法得到的核函数模型稀疏性更好,泛化能力更强。
文摘针对车辆跟踪过程中跟踪目标丢失或者失败的情况,提出一种改进型Camshift(Continuously Adaptive Mean Shift)算法和卡尔曼滤波相结合的跟踪方法。首先,利用卡尔曼滤波器实现跟踪目标的位置估计,以克服目标被遮挡造成的跟踪失败的问题,然后再利用改进型Camshift算法依据目标距离搜索中心的位置,对H分量创建的颜色直方图中的每个像素位进行高斯模型核函数的加权处理,并自适应计算得到最优的搜索窗口,从而改善了传统Camshift不能直接抵制噪声干扰的缺点,解决了因跟踪目标在同色背景噪声干扰下出现的丢失问题。最后通过仿真实验表明:改进型Camshift算法和卡尔曼滤波的结合有效地提高了车辆跟踪的准确性和连续性。
基金The project supported by the Natural Science Foundation of Hebei Province of China under Grant No. A2005000535
文摘The nucleon electromagnetic form factors are investigated within a simple diquark-quark model using the light-front formalism. In this model, baryon is described as a bound state of one quark and one clustering diquark. The calculational results are compared with the experimental ones. We also regard the quarks in a baryon as pointlike constituent quarks.
基金supported by the National Natural Science Foundation of China(No.21673246)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB12020300)
文摘The time-convolutionless （TCL） quantum master equation provides a powerful tool to simulate reduced dynanfics of a quantum system coupled to a bath. The key quantity ill the TCL master equation is the so-called kernel or generator, which describes eflhcts of the bath degrees of freedom. Since the exact TCL generators are usually hard to calculate analytically, most applications of the TCL generalized master equation have relied on approximate generators using second and fourth order perturbative expansions. By using the hierarchical equation of motion （HEOM） and extended HEOM methods, we present a new approach to calculating the exact TCL generator and its high order perturbative expansions. The new approach is applied to the spin-boson model with diflhrent sets of parameters, to investigate the convergence of the high order expansiolls of the TCL generator. We also discuss circumstances where the exact TCL generator becomes singular for the spin-boson model, and a model of excitation energy transfer in the Fenna-Matthews-Olson complex.
文摘We discuss the nucleon spin structure function g<SUB>1</SUB> and the difference between the proton and neutron targets , based on quark model calculation. Quark-hadron duality for the nucleon spin structure function is also analyzed. Effects of the Δ(1232) and Roper P<SUB>11</SUB>(1440) resonances on the spin structure function and on the difference are mentioned. The results of different models for the Roper resonance are also addressed.
文摘We develop a simple analytic calculation for the first order wave function of helium in a model in which nuclear charge screening is caused by repulsive coulomb interaction. The perturbation term, first-order correlation energy, and first-order wave function are divided into two components, one component associated with the repulsive coulomb interaction and the other proportional to magnetic shielding. The resulting first-order wave functions are applied to calculate second-order energies within the model. We find that the second-order energies are independent of the nuclear charge screening constant in the unperturbed Hamiltonian with a central coulomb potential.
文摘This paper put forward the super-resolution image algorithm based on Gauss process regression sparse solution. We establish local Gauss process regression model, to solve the feasibility problem of regression super-resolution problem in solving Gauss process; further use sparse algorithm, not only it can optimize the super parameter of Gauss kernel function, but also to optimize the initial entry training, so as to obtain more accurate regression Gauss process. Experimental results show that： the paper proposed algorithm can does not reduce the image reconstruction results, and it can reduce the computational complexity.
