This paper shows that the multiplicity of the base point locus of a projective rational surface parametrization can be expressed as the degree of the content of a univariate resultant.As a consequence,we get a new pro...This paper shows that the multiplicity of the base point locus of a projective rational surface parametrization can be expressed as the degree of the content of a univariate resultant.As a consequence,we get a new proof of the degree formula relating the degree of the surface,the degree of the parametrization,the base point multiplicity and the degree of the rational map induced by the parametrization.In addition,we extend both formulas to the case of dominant rational maps of the projective plane and describe how the base point loci of a parametrization and its reparametrizations are related.As an application of these results,we explore how the degree of a surface reparametrization is affected by the presence of base points.展开更多
The iterative closest point(ICP)algorithm has the advantages of high accuracy and fast speed for point set registration,but it performs poorly when the point set has a large number of noisy outliers.To solve this prob...The iterative closest point(ICP)algorithm has the advantages of high accuracy and fast speed for point set registration,but it performs poorly when the point set has a large number of noisy outliers.To solve this problem,we propose a new affine registration algorithm based on correntropy which works well in the affine registration of point sets with outliers.Firstly,we substitute the traditional measure of least squares with a maximum correntropy criterion to build a new registration model,which can avoid the influence of outliers.To maximize the objective function,we then propose a robust affine ICP algorithm.At each iteration of this new algorithm,we set up the index mapping of two point sets according to the known transformation,and then compute the closed-form solution of the new transformation according to the known index mapping.Similar to the traditional ICP algorithm,our algorithm converges to a local maximum monotonously for any given initial value.Finally,the robustness and high efficiency of affine ICP algorithm based on correntropy are demonstrated by 2D and 3D point set registration experiments.展开更多
It is discussed in this paper the spaces with σ-point-discrete N_0-weak bases. The main results are： （1） A space X has a σ-compact-finite N_0-weak base if and only if X is a k-space with a σ-point-discrete N_0-w...It is discussed in this paper the spaces with σ-point-discrete N_0-weak bases. The main results are： （1） A space X has a σ-compact-finite N_0-weak base if and only if X is a k-space with a σ-point-discrete N_0-weak base; （2） Under （CH）, every separable space with a σ-point-discrete N_0-weak base has a countable N_0-weak base.展开更多
A novel image stabilization system is presented,which consists of a global feature point tracking based motion estimation,a Kalman filtering based motion smoothing and an image mosaic based panoramic compensation.The ...A novel image stabilization system is presented,which consists of a global feature point tracking based motion estimation,a Kalman filtering based motion smoothing and an image mosaic based panoramic compensation.The global motion is estimated using feature point matching and iteration with the least-square method.Then,the Kalman filter is applied to smooth the original motion vectors to effectively alleviate unwanted camera vibrations and follow the intentional camera scan.Lastly,the loss information of im...展开更多
A Coupling Magneto-Electro-Elastic(MEE)Node-based Smoothed Radial Point Interpolation Method(CM-NS-RPIM)was proposed to solve the free vibration and transient responses of Functionally Graded Magneto-Electro-Elastic(F...A Coupling Magneto-Electro-Elastic(MEE)Node-based Smoothed Radial Point Interpolation Method(CM-NS-RPIM)was proposed to solve the free vibration and transient responses of Functionally Graded Magneto-Electro-Elastic(FGMEE)structures.By introducing the modified Newmark method,the displacement,electrical potential and magnetic potential of the structures under transient mechanical loading were obtained.Based on G space theory and the weakened weak(W2)formulation,the equations of the multi-physics coupling problems were derived.Using triangular background elements,the free vibration and transient responses of three numerical examples were studied.Results proved that CM-NS-RPIM performed better than the standard FEM by reducing the overly-stiff of structures.Moreover,CM-NS-RPIM could reduce the number of nodes while guaranteeing the accuracy.Besides,triangular elements could be generated automatically even for complex geometries.Therefore,the effectiveness and validity of CM-NS-RPIM were demonstrated,which were valuable for the design of intelligence devices,such as energy harvesters and sensors.展开更多
Conventional reliability-based design optimization （RBDO） requires to use the most probable point （MPP） method for a probabilistic analysis of the reliability constraints. A new approach is presented, called as th...Conventional reliability-based design optimization （RBDO） requires to use the most probable point （MPP） method for a probabilistic analysis of the reliability constraints. A new approach is presented, called as the minimum error point （MEP） method or the MEP based method, for reliability-based design optimization, whose idea is to minimize the error produced by approximating performance functions. The MEP based method uses the first order Taylor＇s expansion at MEP instead of MPP. Examples demonstrate that the MEP based design optimization can ensure product reliability at the required level, which is very imperative for many important engineering systems. The MEP based reliability design optimization method is feasible and is considered as an alternative for solving reliability design optimization problems. The MEP based method is more robust than the commonly used MPP based method for some irregular performance functions.展开更多
By means of programs GTMPAC based- on generalized triangle method,analysis and synthesis of mechanism design in accordance with absolutely graphicalmethod( absolutely germetrical method) are developed.In this paper,we...By means of programs GTMPAC based- on generalized triangle method,analysis and synthesis of mechanism design in accordance with absolutely graphicalmethod( absolutely germetrical method) are developed.In this paper,we make aspecial study about centering- point curve and circling- point curve and couplercurves based on Ball’s points.展开更多
A novel diagrammtic method is proposed to show the angular distribution of bases of human protein sequences. Using this method, the distribution sphere[1-4] is divided into four regions with same volume. The picture i...A novel diagrammtic method is proposed to show the angular distribution of bases of human protein sequences. Using this method, the distribution sphere[1-4] is divided into four regions with same volume. The picture is clearer and more intuitive than that in [1] .A rule on the angular distribution of the representative points of bases of protein sequences is given. Besides, in 300 representative pointS of human protein sequence samples we find that there are three (not only one) points outside the sphere.展开更多
Haptic rendering is referred to as an approach for complementing graphical model of the virtual object with mechanics- based properties. As a result, when the user interacts with the virtual object through a haptic de...Haptic rendering is referred to as an approach for complementing graphical model of the virtual object with mechanics- based properties. As a result, when the user interacts with the virtual object through a haptic device, the object can graphically deflect or deform following laws of mechanics. In addition, the user is able to feel the resulting interaction force when interacting with the virtual object. This paper presents a study of defining the levels-of-detail (LOD) in point-based computational mechanics for haptic rendering of objects. The approach uses the description of object as a set of sampled points. In comparison with the finite element method (FEM), point-based approach does not rely on any predefined mesh representation and depends on the point representation of the volume of the object. Different from solving the governing equations of motion representing the entire object based on pre-defined mesh representation which is used in FEM, in point-based modeling approach, the number of points involved in the computation of displacement/deformation can be adaptively defined during the solution cycle. This frame work can offer the implementation of the notion for levels-of-detail techniques for which can be used to tune the haptic rendering environment for in- creased realism and computational efficiency. This paper presents some initial experimental studies in implementing LOD in such environment.展开更多
Interaction rule between representative RE and Sn, Sb, Pb, Cu, S, P low melting point elements respectively in Fe , Cu , Al , Ni base liquid solutions including totally 34 ternary and quarternary systems was inve...Interaction rule between representative RE and Sn, Sb, Pb, Cu, S, P low melting point elements respectively in Fe , Cu , Al , Ni base liquid solutions including totally 34 ternary and quarternary systems was investigated. For each system some thermodynamic properties were obtained, such as the standard free energies of equilibrium reactions, activity interaction coefficients etc ..展开更多
本文提出了一种结合Voronoi图和深度强化学习的机器人路径规划方法.在全局规划方面,通过Voronoi图构建“安全区域”,利用A*算法和关键路径点提取算法优化路径点,为局部规划提供目标.局部规划采用融合阶段关键点与均衡回放策略的RainbowD...本文提出了一种结合Voronoi图和深度强化学习的机器人路径规划方法.在全局规划方面,通过Voronoi图构建“安全区域”,利用A*算法和关键路径点提取算法优化路径点,为局部规划提供目标.局部规划采用融合阶段关键点与均衡回放策略的RainbowDQN(stage-key&weight-balanced replay Rainbow deep Q-network,SW-RDQN)算法,通过3项关键设计提升复杂动态环境下的导航适应性:首先,采用多阶段路径分割策略对全局路径进行划分与剪枝,提取并保留关键路径点信息;其次,结合轨迹落点预测与环境势场设计奖励函数,引导智能体学习更安全有效的避障行为;最后,采用基于奖励与TD误差动态加权的优先经验回放,通过偏移与对数归一化提升关键经验采样概率,从而提高训练效率.状态输入融合了卷积和多层感知机提取信息,取若干场景帧送入长短期记忆网络模型,最后由稠密层做出决策,提升了机器人对动态环境的感知和响应能力.该方法有效提升了机器人在动态环境中的路径规划精度与鲁棒性.展开更多
基金partially supported by FEDER/Ministerio de Ciencia,Innovación y Universidades-Agencia Estatal de Investigación/MTM2017-88796-P(Symbolic Computation:new challenges in Algebra and Geometry together with its applications)。
文摘This paper shows that the multiplicity of the base point locus of a projective rational surface parametrization can be expressed as the degree of the content of a univariate resultant.As a consequence,we get a new proof of the degree formula relating the degree of the surface,the degree of the parametrization,the base point multiplicity and the degree of the rational map induced by the parametrization.In addition,we extend both formulas to the case of dominant rational maps of the projective plane and describe how the base point loci of a parametrization and its reparametrizations are related.As an application of these results,we explore how the degree of a surface reparametrization is affected by the presence of base points.
基金supported in part by the National Natural Science Foundation of China(61627811,61573274,61673126,U1701261)
文摘The iterative closest point(ICP)algorithm has the advantages of high accuracy and fast speed for point set registration,but it performs poorly when the point set has a large number of noisy outliers.To solve this problem,we propose a new affine registration algorithm based on correntropy which works well in the affine registration of point sets with outliers.Firstly,we substitute the traditional measure of least squares with a maximum correntropy criterion to build a new registration model,which can avoid the influence of outliers.To maximize the objective function,we then propose a robust affine ICP algorithm.At each iteration of this new algorithm,we set up the index mapping of two point sets according to the known transformation,and then compute the closed-form solution of the new transformation according to the known index mapping.Similar to the traditional ICP algorithm,our algorithm converges to a local maximum monotonously for any given initial value.Finally,the robustness and high efficiency of affine ICP algorithm based on correntropy are demonstrated by 2D and 3D point set registration experiments.
基金Supported by the National Natural Science Foundation of China (10971185, 11171162, 11201053)China Postdoctoral Science Foundation funded project (20090461093, 201003571)+1 种基金Jiangsu Planned Projects for Teachers Overseas Research FundsTaizhou Teachers College Research Funds
文摘It is discussed in this paper the spaces with σ-point-discrete N_0-weak bases. The main results are： （1） A space X has a σ-compact-finite N_0-weak base if and only if X is a k-space with a σ-point-discrete N_0-weak base; （2） Under （CH）, every separable space with a σ-point-discrete N_0-weak base has a countable N_0-weak base.
基金supported by the National "863 Program" on High Technology Research and Development of China (Grant No.2006AA01Z127)
文摘A novel image stabilization system is presented,which consists of a global feature point tracking based motion estimation,a Kalman filtering based motion smoothing and an image mosaic based panoramic compensation.The global motion is estimated using feature point matching and iteration with the least-square method.Then,the Kalman filter is applied to smooth the original motion vectors to effectively alleviate unwanted camera vibrations and follow the intentional camera scan.Lastly,the loss information of im...
基金co-supported by the National Key R&D Program of China(Nos.2018YFF01012401-05)the National Natural Science Foundation of China(No.51975243)+2 种基金Jilin Provincial Department of Education(No.JJKH20180084KJ),Chinathe Fundamental Research Funds for the Central Universities and Jilin Provincial Department of Science&Technology Fund Project,China(Nos.20170101043JC and 20180520072JH)Graduate Innovation Fund of Jilin University,China(No.101832018C184).
文摘A Coupling Magneto-Electro-Elastic(MEE)Node-based Smoothed Radial Point Interpolation Method(CM-NS-RPIM)was proposed to solve the free vibration and transient responses of Functionally Graded Magneto-Electro-Elastic(FGMEE)structures.By introducing the modified Newmark method,the displacement,electrical potential and magnetic potential of the structures under transient mechanical loading were obtained.Based on G space theory and the weakened weak(W2)formulation,the equations of the multi-physics coupling problems were derived.Using triangular background elements,the free vibration and transient responses of three numerical examples were studied.Results proved that CM-NS-RPIM performed better than the standard FEM by reducing the overly-stiff of structures.Moreover,CM-NS-RPIM could reduce the number of nodes while guaranteeing the accuracy.Besides,triangular elements could be generated automatically even for complex geometries.Therefore,the effectiveness and validity of CM-NS-RPIM were demonstrated,which were valuable for the design of intelligence devices,such as energy harvesters and sensors.
基金This project is supported by National Natural Science Foundation of China(No.50575072)Outstanding Youth Fund of Hunan Education Department, China (No.04B007).
文摘Conventional reliability-based design optimization （RBDO） requires to use the most probable point （MPP） method for a probabilistic analysis of the reliability constraints. A new approach is presented, called as the minimum error point （MEP） method or the MEP based method, for reliability-based design optimization, whose idea is to minimize the error produced by approximating performance functions. The MEP based method uses the first order Taylor＇s expansion at MEP instead of MPP. Examples demonstrate that the MEP based design optimization can ensure product reliability at the required level, which is very imperative for many important engineering systems. The MEP based reliability design optimization method is feasible and is considered as an alternative for solving reliability design optimization problems. The MEP based method is more robust than the commonly used MPP based method for some irregular performance functions.
文摘By means of programs GTMPAC based- on generalized triangle method,analysis and synthesis of mechanism design in accordance with absolutely graphicalmethod( absolutely germetrical method) are developed.In this paper,we make aspecial study about centering- point curve and circling- point curve and couplercurves based on Ball’s points.
文摘A novel diagrammtic method is proposed to show the angular distribution of bases of human protein sequences. Using this method, the distribution sphere[1-4] is divided into four regions with same volume. The picture is clearer and more intuitive than that in [1] .A rule on the angular distribution of the representative points of bases of protein sequences is given. Besides, in 300 representative pointS of human protein sequence samples we find that there are three (not only one) points outside the sphere.
文摘Haptic rendering is referred to as an approach for complementing graphical model of the virtual object with mechanics- based properties. As a result, when the user interacts with the virtual object through a haptic device, the object can graphically deflect or deform following laws of mechanics. In addition, the user is able to feel the resulting interaction force when interacting with the virtual object. This paper presents a study of defining the levels-of-detail (LOD) in point-based computational mechanics for haptic rendering of objects. The approach uses the description of object as a set of sampled points. In comparison with the finite element method (FEM), point-based approach does not rely on any predefined mesh representation and depends on the point representation of the volume of the object. Different from solving the governing equations of motion representing the entire object based on pre-defined mesh representation which is used in FEM, in point-based modeling approach, the number of points involved in the computation of displacement/deformation can be adaptively defined during the solution cycle. This frame work can offer the implementation of the notion for levels-of-detail techniques for which can be used to tune the haptic rendering environment for in- creased realism and computational efficiency. This paper presents some initial experimental studies in implementing LOD in such environment.
基金Project Sponsored by the National Natural Science Foundation
文摘Interaction rule between representative RE and Sn, Sb, Pb, Cu, S, P low melting point elements respectively in Fe , Cu , Al , Ni base liquid solutions including totally 34 ternary and quarternary systems was investigated. For each system some thermodynamic properties were obtained, such as the standard free energies of equilibrium reactions, activity interaction coefficients etc ..
文摘本文提出了一种结合Voronoi图和深度强化学习的机器人路径规划方法.在全局规划方面,通过Voronoi图构建“安全区域”,利用A*算法和关键路径点提取算法优化路径点,为局部规划提供目标.局部规划采用融合阶段关键点与均衡回放策略的RainbowDQN(stage-key&weight-balanced replay Rainbow deep Q-network,SW-RDQN)算法,通过3项关键设计提升复杂动态环境下的导航适应性:首先,采用多阶段路径分割策略对全局路径进行划分与剪枝,提取并保留关键路径点信息;其次,结合轨迹落点预测与环境势场设计奖励函数,引导智能体学习更安全有效的避障行为;最后,采用基于奖励与TD误差动态加权的优先经验回放,通过偏移与对数归一化提升关键经验采样概率,从而提高训练效率.状态输入融合了卷积和多层感知机提取信息,取若干场景帧送入长短期记忆网络模型,最后由稠密层做出决策,提升了机器人对动态环境的感知和响应能力.该方法有效提升了机器人在动态环境中的路径规划精度与鲁棒性.
