A characteristic parameter α_D of a domain D in R^n is introduced. D is unifonm if and only if α_D<∞. And α_D=1 if D is a ball or a half space. It is proved that the decomposability and the uniformity of a doma...A characteristic parameter α_D of a domain D in R^n is introduced. D is unifonm if and only if α_D<∞. And α_D=1 if D is a ball or a half space. It is proved that the decomposability and the uniformity of a domain in R^n are still equivalent. Some problems on uniform domains and decomposition domains are discussed.展开更多
红外探测器所成图像存在固有非均匀性缺陷,现有的基于场景的最小均方差(least mean square,LMS)校正算法在对图像进行非均匀性校正时极易引入鬼影,严重限制了校正效果。针对这一瓶颈,本研究以时域门控鬼影抑制技术为基础,创新性地将韦...红外探测器所成图像存在固有非均匀性缺陷,现有的基于场景的最小均方差(least mean square,LMS)校正算法在对图像进行非均匀性校正时极易引入鬼影,严重限制了校正效果。针对这一瓶颈,本研究以时域门控鬼影抑制技术为基础,创新性地将韦伯定律引入红外图像非均匀性校正体系,提出双门控LMS非均匀性校正方法。该方法摒弃了“绝对无鬼影”的理想化数学优化目标,转而以鬼影处于人眼视觉感知阈值之下为核心准则进行校正;构建了全新的“运动终止”目标检测模型以获取可校正像素增量;并通过预判增量校正目标的运动趋势来确定其校正幅度,从而达到各类复杂场景下图像质量和鬼影抑制性能的协同优化。实验结果证明,双门控法可与现有各类基线校正算法灵活叠加部署,具备优异的算法普适性;肉眼观测和各类图像量化指标均显示,相较于传统的时域门控算法,该方法可在不降低鬼影抑制效果的前提下,将校正效率提高最高达60%。展开更多
Let D and D＇ be domains in real Banach spaces of dimension at least 2. The main aim of this paper is to study certain arc distortion properties in the quasihyperbolic metric defined in real Banach spaces. In particul...Let D and D＇ be domains in real Banach spaces of dimension at least 2. The main aim of this paper is to study certain arc distortion properties in the quasihyperbolic metric defined in real Banach spaces. In particular, when D＇ is a QH inner C-uniform domain with C being a slow （or a convex domain）, we investigate the following： For positive constants c, h, C, M, suppose a homeomorphism f ： D → D＇ takes each of the 10-neargeodesics in D to （c, h）-solid in D＇. Then f is C-coarsely M- Lipschitz in the quasihyperbolic metric. These are generalizations of the corresponding result obtained recently by Viiisiilg.展开更多
文摘A characteristic parameter α_D of a domain D in R^n is introduced. D is unifonm if and only if α_D<∞. And α_D=1 if D is a ball or a half space. It is proved that the decomposability and the uniformity of a domain in R^n are still equivalent. Some problems on uniform domains and decomposition domains are discussed.
文摘红外探测器所成图像存在固有非均匀性缺陷,现有的基于场景的最小均方差(least mean square,LMS)校正算法在对图像进行非均匀性校正时极易引入鬼影,严重限制了校正效果。针对这一瓶颈,本研究以时域门控鬼影抑制技术为基础,创新性地将韦伯定律引入红外图像非均匀性校正体系,提出双门控LMS非均匀性校正方法。该方法摒弃了“绝对无鬼影”的理想化数学优化目标,转而以鬼影处于人眼视觉感知阈值之下为核心准则进行校正;构建了全新的“运动终止”目标检测模型以获取可校正像素增量;并通过预判增量校正目标的运动趋势来确定其校正幅度,从而达到各类复杂场景下图像质量和鬼影抑制性能的协同优化。实验结果证明,双门控法可与现有各类基线校正算法灵活叠加部署,具备优异的算法普适性;肉眼观测和各类图像量化指标均显示,相较于传统的时域门控算法,该方法可在不降低鬼影抑制效果的前提下,将校正效率提高最高达60%。
基金Supported by National Natural Science Foundation of China （Grant No. 11071063）, Tianyuan Foundation （Grant No. 10926068） and Scientific Research Fund of Hunan Provincial Education Department （Grant No. 09C635）Acknowledgements The authors thank the referee very much for his （or her） careflfl reading of this paper and many useful suggestions and the support of the Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hu＇nan Province.
文摘Let D and D＇ be domains in real Banach spaces of dimension at least 2. The main aim of this paper is to study certain arc distortion properties in the quasihyperbolic metric defined in real Banach spaces. In particular, when D＇ is a QH inner C-uniform domain with C being a slow （or a convex domain）, we investigate the following： For positive constants c, h, C, M, suppose a homeomorphism f ： D → D＇ takes each of the 10-neargeodesics in D to （c, h）-solid in D＇. Then f is C-coarsely M- Lipschitz in the quasihyperbolic metric. These are generalizations of the corresponding result obtained recently by Viiisiilg.
