In the traditional power transmission network planning,deterministic analysis methods are widely used.In such methods,all contingencies are deemed to have the same occurrence probability,which is not reasonable.In thi...In the traditional power transmission network planning,deterministic analysis methods are widely used.In such methods,all contingencies are deemed to have the same occurrence probability,which is not reasonable.In this paper,risk assessment is introduced to the process of transmission network planning considering the probabilistic characteristics of contingencies.Risk indices are given to determine the weak points of the transmission network based on local information,such as bus risk,line overload risk,contingency severity.The indices are calculated by the optimal cost control method based on risk theory,which can help planners to quickly determine weak points in the planning and find solution to them.For simplification,only line overload violation is considered.Finally,the proposed method is validated by an IEEE-RTS test system and a real power system in China from two aspects.In the first case,the original system is evaluated by the proposed method to find the weak points,and then four planning schemes are established,among which the best scheme is selected.In the second case,four initial planning schemes are established by combining the experiences of planners,and after the evaluation by using the proposed method,the best planning scheme is improved based on the information of weak points in the initial schemes,and the risk of improved scheme is reduced from 42 531.86 MW·h per year to 4 431.26 MW·h per year.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
In this paper, some new existence and uniqueness of points of coincidence of weakly compatible pair of mappings is obtained, which does not satisfy continuity and commutativity. The conditions are weaker than the usua...In this paper, some new existence and uniqueness of points of coincidence of weakly compatible pair of mappings is obtained, which does not satisfy continuity and commutativity. The conditions are weaker than the usual conditions in cone metric spaces.展开更多
In this paper, we give existence theorems of common fixed points for two mappings with a weakly C*-contractive condition on partially ordered 2-metric spaces and give a sufficient condition under which there exists a ...In this paper, we give existence theorems of common fixed points for two mappings with a weakly C*-contractive condition on partially ordered 2-metric spaces and give a sufficient condition under which there exists a unique common fixed point.展开更多
In this paper, using the context of complete partial metric spaces, some common fixed point results of maps that satisfy the generalized （ψ, Ф）-weak contractive conditions are obtained. Our results generalize, ext...In this paper, using the context of complete partial metric spaces, some common fixed point results of maps that satisfy the generalized （ψ, Ф）-weak contractive conditions are obtained. Our results generalize, extend, unify, enrich and complement many existing results in the literature. Example are given showing the validaty of our results.展开更多
传统同时定位与地图构建(simultaneous localization and mapping,SLAM)在弱纹理场景中的鲁棒性差,在动态场景中受动态物体干扰。针对这些问题,提出了动态视觉SLAM。首先,在视觉前端使用几何对应网络2(geometric correspondence network...传统同时定位与地图构建(simultaneous localization and mapping,SLAM)在弱纹理场景中的鲁棒性差,在动态场景中受动态物体干扰。针对这些问题,提出了动态视觉SLAM。首先,在视觉前端使用几何对应网络2(geometric correspondence network version 2,GCNv2)提取特征点并生成二值描述子,提高SLAM在弱纹理场景中的鲁棒性;然后,引入目标检测网络对动态物体进行检测,获取当前帧的语义信息,结合多视图几何剔除动态物体,去除动态物体对SLAM的干扰。实验结果表明:在弱纹理场景中,所提方法可以持续提取足够数量的高质量特征点;在存在动态物体干扰的场景中,所提方法的绝对位姿误差和相对位姿误差较小;在静态场景中,所提方法的性能仍然较优。展开更多
针对纹理稀疏及光照变化的室内场景下,仅基于单一点特征的视觉同时定位与建图(Simultaneous Localization and Mapping,SLAM)算法位姿估计精度低甚至完全失效的问题,结合稳定性更强的线、面特征,提出了一种基于点线面特征的位姿解耦RGBD...针对纹理稀疏及光照变化的室内场景下,仅基于单一点特征的视觉同时定位与建图(Simultaneous Localization and Mapping,SLAM)算法位姿估计精度低甚至完全失效的问题,结合稳定性更强的线、面特征,提出了一种基于点线面特征的位姿解耦RGBD-SLAM系统。充分利用不同特征的互补优势和场景的结构化特性,采用位姿解耦估计的思想,通过曼哈顿世界假设实现无漂移的旋转估计,并最小化多特征联合误差函数估计平移,从而减小了传统SLAM系统采用逐帧跟踪的位姿估计方式带来的累积误差影响,提高了系统的位姿估计精度,并据此构建了环境信息丰富的点线面结构地图。实验结果表明,所提SLAM系统在ICL-NUIM数据集的8个子序列中,平均绝对轨迹精度相较于ORBSLAM2,PL-SLAM和SP-SLAM分别提升了54.5%,23.5%和28.3%;在TUM RGBD数据集的11个子序列中,分别提升了33.9%,26.2%和11.7%,表现出更优的全局定位性能和更强的系统鲁棒性;且所构建的点线面结构地图能够更好地描述环境。展开更多
基金Supported by Major State Basic Research Program of China ("973" Program,No. 2009CB219700 and No. 2010CB23460)Tianjin Municipal Science and Technology Development Program (No. 09JCZDJC25000)Specialized Research Fund for the Doctoral Program of Higher Education of China (No.20090032110064)
文摘In the traditional power transmission network planning,deterministic analysis methods are widely used.In such methods,all contingencies are deemed to have the same occurrence probability,which is not reasonable.In this paper,risk assessment is introduced to the process of transmission network planning considering the probabilistic characteristics of contingencies.Risk indices are given to determine the weak points of the transmission network based on local information,such as bus risk,line overload risk,contingency severity.The indices are calculated by the optimal cost control method based on risk theory,which can help planners to quickly determine weak points in the planning and find solution to them.For simplification,only line overload violation is considered.Finally,the proposed method is validated by an IEEE-RTS test system and a real power system in China from two aspects.In the first case,the original system is evaluated by the proposed method to find the weak points,and then four planning schemes are established,among which the best scheme is selected.In the second case,four initial planning schemes are established by combining the experiences of planners,and after the evaluation by using the proposed method,the best planning scheme is improved based on the information of weak points in the initial schemes,and the risk of improved scheme is reduced from 42 531.86 MW·h per year to 4 431.26 MW·h per year.
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 Fundamental Research Fund of Sichuan Provincial Science and Technology Department(2012JYZ019)
文摘In this paper, some new existence and uniqueness of points of coincidence of weakly compatible pair of mappings is obtained, which does not satisfy continuity and commutativity. The conditions are weaker than the usual conditions in cone metric spaces.
文摘In this paper, we give existence theorems of common fixed points for two mappings with a weakly C*-contractive condition on partially ordered 2-metric spaces and give a sufficient condition under which there exists a unique common fixed point.
文摘In this paper, using the context of complete partial metric spaces, some common fixed point results of maps that satisfy the generalized （ψ, Ф）-weak contractive conditions are obtained. Our results generalize, extend, unify, enrich and complement many existing results in the literature. Example are given showing the validaty of our results.
文摘传统同时定位与地图构建(simultaneous localization and mapping,SLAM)在弱纹理场景中的鲁棒性差,在动态场景中受动态物体干扰。针对这些问题,提出了动态视觉SLAM。首先,在视觉前端使用几何对应网络2(geometric correspondence network version 2,GCNv2)提取特征点并生成二值描述子,提高SLAM在弱纹理场景中的鲁棒性;然后,引入目标检测网络对动态物体进行检测,获取当前帧的语义信息,结合多视图几何剔除动态物体,去除动态物体对SLAM的干扰。实验结果表明:在弱纹理场景中,所提方法可以持续提取足够数量的高质量特征点;在存在动态物体干扰的场景中,所提方法的绝对位姿误差和相对位姿误差较小;在静态场景中,所提方法的性能仍然较优。
文摘针对纹理稀疏及光照变化的室内场景下,仅基于单一点特征的视觉同时定位与建图(Simultaneous Localization and Mapping,SLAM)算法位姿估计精度低甚至完全失效的问题,结合稳定性更强的线、面特征,提出了一种基于点线面特征的位姿解耦RGBD-SLAM系统。充分利用不同特征的互补优势和场景的结构化特性,采用位姿解耦估计的思想,通过曼哈顿世界假设实现无漂移的旋转估计,并最小化多特征联合误差函数估计平移,从而减小了传统SLAM系统采用逐帧跟踪的位姿估计方式带来的累积误差影响,提高了系统的位姿估计精度,并据此构建了环境信息丰富的点线面结构地图。实验结果表明,所提SLAM系统在ICL-NUIM数据集的8个子序列中,平均绝对轨迹精度相较于ORBSLAM2,PL-SLAM和SP-SLAM分别提升了54.5%,23.5%和28.3%;在TUM RGBD数据集的11个子序列中,分别提升了33.9%,26.2%和11.7%,表现出更优的全局定位性能和更强的系统鲁棒性;且所构建的点线面结构地图能够更好地描述环境。
