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Strong Convergence and Its Rate of Modified Partitioning Estimation for Nonparametric Regression Function under Dependence Samples 被引量:5
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作者 凌能祥 《Northeastern Mathematical Journal》 CSCD 2004年第3期349-354,共6页
In this paper, we study the strong consistency and convergence rate for modified partitioning estimation of regression function under samples that are ψ-mixing with identically distribution.
关键词 partitioning esfimation strong convergence convergence rate nonpara-metric regression function Ψ-MIXING
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Generalised Error Functions from the Kerr Metric
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作者 唐文林 罗子人 刘润球 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第3期12-16,共5页
Motivated by the effort to understand the mathematical structure underlying the Teukolsky equations in a Kerr metric background, a homogeneous integral equation related to the prolate spheroidal function is studied. F... Motivated by the effort to understand the mathematical structure underlying the Teukolsky equations in a Kerr metric background, a homogeneous integral equation related to the prolate spheroidal function is studied. From the consideration of the Fredholm determinant of the integral equation, a family of generalized error function is defined, with which the Fredholm determinant of the sinc kernel is also evaluated. An analytic solution of a special ease of the fifth Painlev~ transcendent is then worked out explicitly. 展开更多
关键词 of IS exp in Generalised Error functions from the Kerr metric from
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Common Fixed Point Results for Quasi-contractions Involving Altering Distance Functions in Ordered Cone Metric Spaces 被引量:1
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作者 SONG Ji-ping WANG Mao-fa 《Chinese Quarterly Journal of Mathematics》 2018年第1期1-16,共16页
Some common fixed point results for mappings satisfying a quasi-contractive condition which involves altering distance functions are obtained in partially ordered complete cone metric spaces. A sufficient condition fo... Some common fixed point results for mappings satisfying a quasi-contractive condition which involves altering distance functions are obtained in partially ordered complete cone metric spaces. A sufficient condition for the uniqueness of common fixed point is proved. Also, an example is given to support our results. 展开更多
关键词 partially ordered cone metric space quasi-contraction common fixed point altering distance function
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AXISYMMETRIC BENDING OF TWO-DIRECTIONAL FUNCTIONALLY GRADED CIRCULAR AND ANNULAR PLATES 被引量:6
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作者 Guojun Nie Zheng Zhong 《Acta Mechanica Solida Sinica》 SCIE EI 2007年第4期289-295,共7页
Assuming the material properties varying with an exponential law both in the thick- ness and radial directions, axisymmetric bending of two-directional functionally graded circular and annular plates is studied using ... Assuming the material properties varying with an exponential law both in the thick- ness and radial directions, axisymmetric bending of two-directional functionally graded circular and annular plates is studied using the semi-analytical numerical method in this paper. The deflections and stresses of the plates are presented. Numerical results show the well accuracy and convergence of the method. Compared with the finite element method, the semi-analytical nu- merical method is with great advantage in the computational efficiency. Moreover, study on ax- isymmetric bending of two-directional functionally graded annular plate shows that such plates have better performance than those made of isotropic homogeneous materials or one-directional functionally graded materials. Two-directional functionally graded material is a potential alternative to the one-directional functionally graded material. And the integrated design of materials and structures can really be achieved in two-directional functionally graded materials. 展开更多
关键词 two-directional functionally graded materials circular and annular plates axisym-metric bending semi-analytical numerical method integrated design
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二维单项式多面体与复欧氏空间的公共子流形
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作者 程晓亮 桂琳 马会波 《贵州师范大学学报(自然科学版)》 北大核心 2025年第5期92-96,共5页
K hler流形间的全纯等距嵌入问题是多复变领域的热点问题之一。单项式多面体是Hartogs三角形的非平凡推广,研究其与复欧氏空间是否具有公共子流形是有意义的。借助Nash函数的性质及二维单项式多面体的Bergman核函数,得到具有Bergman度... K hler流形间的全纯等距嵌入问题是多复变领域的热点问题之一。单项式多面体是Hartogs三角形的非平凡推广,研究其与复欧氏空间是否具有公共子流形是有意义的。借助Nash函数的性质及二维单项式多面体的Bergman核函数,得到具有Bergman度量的二维单项式多面体与具有平坦度量的复欧氏空间不存在公共的K hler子流形,即二维单项式多面体与复欧氏空间是不相关的。 展开更多
关键词 单项式多面体 全纯等距嵌入 BERGMAN度量 Nash函数
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基于可靠性函数的极化码PSS-RF-SCL译码算法
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作者 袁建国 杨德意 向锦能 《半导体光电》 北大核心 2025年第3期515-521,共7页
针对串行抵消列表(Successive Cancellation List,SCL)译码框架下基于搜索集的路径分裂选择策略的缺陷,提出两种改进策略:基于可靠性函数的路径分裂策略和依靠辅助路径度量值(Auxiliary Path Metric,APM)的剪枝策略。在此基础上,提出一... 针对串行抵消列表(Successive Cancellation List,SCL)译码框架下基于搜索集的路径分裂选择策略的缺陷,提出两种改进策略:基于可靠性函数的路径分裂策略和依靠辅助路径度量值(Auxiliary Path Metric,APM)的剪枝策略。在此基础上,提出一种新的译码算法——基于可靠性函数的路径分裂选择策略辅助串行抵消列表(Path Splitting Selecting Strategy Based on Reliability Function under the Successive Cancellation List,PSS-RF-SCL)译码算法。该算法在译码阶段,每个信息比特在进行路径分裂前,会计算所有路径的路径度量(Path Metric,PM)值。利用这些PM值,进一步计算该比特的可靠性函数值。算法将可靠性函数值低于其平均值(即阈值α)的信息比特视为需要进行路径分裂的比特,从而减少了多余的路径分裂次数。此外,算法计算每条路径的APM值,并将APM值高于正确译码路径的APM平均值(即阈值β)的路径视为不可靠路径,对不可靠路径进行剪枝,有效控制了译码列表总数。仿真结果表明,相较于传统的基于搜索集的路径分裂策略辅助的SCL译码算法,所提出的PSS-RF-SCL译码算法在保持相同译码性能的前提条件下,显著降低了译码复杂度。 展开更多
关键词 极化码 PSS-RF-SCL译码 可靠性函数 辅助路径度量值 路径分裂
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Spherical Symmetric Solitons of Interacting Spinor, Scalar and Gravitational Fields in General Relativity
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作者 Jonas Edou Alain Adomou Siaka Massou 《Journal of High Energy Physics, Gravitation and Cosmology》 2021年第1期52-65,共14页
The concept of soliton as regular localized stable solutions of nonlinear differential equations is being widely utilized in pure science for various aims. In present analysis, the soliton concept is used as a model i... The concept of soliton as regular localized stable solutions of nonlinear differential equations is being widely utilized in pure science for various aims. In present analysis, the soliton concept is used as a model in order to describe the configurations of elementary particles in general relativity. To this end, our study deals with the spherical symmetric solitons of interacting Spinor, Scalar and Gravitational Fields in General Relativity. Thus, exact spherical symmetric general solutions to the interaction of spinor, scalar and gravitational field equations have been obtained. The Einstein equations have been transformed into a Liouville equation type and solved. Let us emphasize that these solutions are regular with localized energy density and finite total energy. In addition, the total charge and spin are limited. Moreover, the obtained solutions are soliton-like solutions. These solutions can be used in order to describe the configurations of elementary particles. 展开更多
关键词 Liouville Type Equation Elementary Particles Einstein’s Equations metric functions
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一种基于应用驱动的物理不可克隆函数分析方法
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作者 许嘉鑫 孟坤 《北京信息科技大学学报(自然科学版)》 2025年第4期76-82,共7页
物理不可克隆函数(physical unclonable functions,PUFs)在身份认证、密钥派生、知识产权保护等领域展现出显著优势。随着其不断发展,基于不同原理的PUF设备层出不穷,但现有的性能评估指标和测试方法仍然不够完善,尚未形成统一的标准。... 物理不可克隆函数(physical unclonable functions,PUFs)在身份认证、密钥派生、知识产权保护等领域展现出显著优势。随着其不断发展,基于不同原理的PUF设备层出不穷,但现有的性能评估指标和测试方法仍然不够完善,尚未形成统一的标准。针对这一问题,围绕不同应用场景的需求,整理并提出应用驱动的PUF性能评估指标体系,并探讨如何根据应用需求选择合适的评估方法。最后,以静态随机存取存储器(static random access memory,SRAM)PUF为例设计相应的测试平台,通过实验验证所提方法的有效性和应用价值。 展开更多
关键词 物理不可克隆函数 评价指标 测试平台 静态随机存储器
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插值点法FGM梯度源建模及其可视化分析
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作者 韩晓伟 韩硕 +1 位作者 马硕 段国林 《机械设计与制造》 北大核心 2025年第4期274-277,282,共5页
功能梯度材料由于兼顾控材、控性等多种优良性能,近些年被广泛应用于3D打印领域。功能梯度材料建模则是3D打印技术关键问题之一,而功能梯度材料建模的关键,则是将几何空间与材料空间相结合的过程。设计功能梯度材料时往往会不断改变、... 功能梯度材料由于兼顾控材、控性等多种优良性能,近些年被广泛应用于3D打印领域。功能梯度材料建模则是3D打印技术关键问题之一,而功能梯度材料建模的关键,则是将几何空间与材料空间相结合的过程。设计功能梯度材料时往往会不断改变、调试材料分布函数以达到所需要的梯度变化规律。对简化材料分布函数进行研究,找到其系数之间关系,以方便修改系数达到所需要的梯度规律。提出一种基于插值点的功能梯度材料梯度源建模方法,该方法将模型材料信息附着到插值点上,得到一条带有材质信息的特殊线段(直线段或曲线段),而后将此特殊线段经过一系列空间变换而得到功能梯度材料实体模型,实现材料信息与几何模型整体表达。利用VS2019和OpenGL编程语言对该方法所建立的功能梯度材料模型进行可视化分析,最后给出可视化分析实例。 展开更多
关键词 功能梯度材料建模 材料分布函数 插值点 几何空间 材料空间 可视化分析
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自然刺激fMRI脑网络指标的年龄差异和复本信度研究
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作者 袁文娟 周燕飞 +1 位作者 杨立状 李海 《蚌埠医科大学学报》 2025年第6期792-796,共5页
目的:系统评估自然刺激功能磁共振成像(fMRI)脑网络指标的年龄差异及复本信度。方法:采用电影《神探夏洛克》和《红气球》作为自然刺激材料,采集46名健康年轻人[(28.9±5.23)岁]和32名健康老年人[(59.5±6.33)岁]的fMRI数据,并... 目的:系统评估自然刺激功能磁共振成像(fMRI)脑网络指标的年龄差异及复本信度。方法:采用电影《神探夏洛克》和《红气球》作为自然刺激材料,采集46名健康年轻人[(28.9±5.23)岁]和32名健康老年人[(59.5±6.33)岁]的fMRI数据,并计算其功能连接和图论指标,比较不同年龄群体的特征及复本信度。结果:年轻人在部分脑网络中表现出更强的功能连接和更优的图论特征,且这些指标的复本信度均显著高于老年人。结论:功能连接和图论指标在不同年龄群体中表现出显著的年龄效应及复本信度差异,进一步支持了自然刺激fMRI在脑网络功能连接研究中的应用价值。 展开更多
关键词 功能磁共振成像 自然刺激 功能连接 图论指标 年龄差异 复本信度
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石亭江底栖动物群落结构季节变化与生态评价
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作者 李松忆 郑珊 周雄冬 《人民长江》 北大核心 2025年第1期67-73,共7页
汶川地震后石亭江山前河段冲刷严重,对河流生态产生重要影响,然而目前尚缺乏对山前冲刷河段的定量生态评价。选取石亭江、绵远河和湔江为研究对象,根据2021年秋季(10月)和2022年夏季(7月)采集的大型无脊椎底栖动物样本与环境观测数据,... 汶川地震后石亭江山前河段冲刷严重,对河流生态产生重要影响,然而目前尚缺乏对山前冲刷河段的定量生态评价。选取石亭江、绵远河和湔江为研究对象,根据2021年秋季(10月)和2022年夏季(7月)采集的大型无脊椎底栖动物样本与环境观测数据,分析了石亭江底栖动物群落结构、多样性、功能摄食类群和功能习性类群的季节变化特点。结果表明:石亭江秋季共采集底栖动物54种,隶属4门6纲35科,夏季共采集到底栖动物33种,隶属1门1纲18科,其中牧食收集者为优势程度最大的功能摄食类群,捕食者的优势程度最小,秋季固着型生物的优势程度最大,夏季蔓生型生物的优势程度最大,攀爬型生物的优势程度在秋季和夏季均为最小。基于底栖动物完整性评价的多参数(MMI)指数,将3条河流栖息地斑块的生态质量划分为极差、差、中等、良好和极好5个等级。结果显示:3条河流栖息地斑块生态质量整体为良好,局部为中等;绵远河与湔江的栖息地斑块生态质量整体高于石亭江;秋季石亭江栖息地斑块的生态质量好于夏季。 展开更多
关键词 大型无脊椎底栖动物 季节变化 功能摄食类群 功能习性类群 多参数(MMI)指数 石亭江
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基于图论分析模拟长航时飞行状态下睡眠剥夺对脑功能连接的影响及特征
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作者 缪建良 李相生 +6 位作者 刘晓宇 乔克印 王巍 钱忠立 陈奋扬 肖寒 田雅军 《空军航空医学》 2025年第5期433-437,共5页
目的通过图论的分析方法,探讨模拟长航时飞行状态下睡眠剥夺对脑功能连接的影响,为制定干预措施和保障飞行安全提供理论依据。方法2020年6月—2023年12月选取空军某单位共44名受试者,进行24 h睡眠剥夺试验,试验前后分别进行静息态功能... 目的通过图论的分析方法,探讨模拟长航时飞行状态下睡眠剥夺对脑功能连接的影响,为制定干预措施和保障飞行安全提供理论依据。方法2020年6月—2023年12月选取空军某单位共44名受试者,进行24 h睡眠剥夺试验,试验前后分别进行静息态功能磁共振(resting-state functional magnetic resonance imaging,rs-fMRI)检查,使用图论指标与脑网络指标计算,对rs-fMRI的时间序列和功能连接矩阵进行提取及可视化,将获得的各脑区的度、局部效率、聚类系数和每名受试者的全局网络特征(包括平均局部效率、桥接连接等)进行24 h睡眠剥夺前后比较分析,评估睡眠剥夺对大脑功能连接的影响。结果睡眠剥夺后较睡眠剥夺前,右侧眶部额中回、左侧枕下回的局部效率(Z/t=2.026、3.532,P_(FDR)=0.049、<0.001)和聚类系数增加(t=2.377、3.146,P_(FDR)=0.022、0.003),右侧枕中回的度值增加(t=2.096,P_(FDR)=0.042),左侧颞上回、右侧颞横回、左侧脑岛的度值和右侧颞横回的局部效率降低(Z/t=-2.026、2.177、2.959、2.177,P_(FDR)=0.049、0.035、0.005、0.033);全局网络指标中,平均局部效率和桥接连接增加(t=2.090、2.310,P=0.042、0.025)。结论睡眠剥夺通过改变脑功能连接模式影响模拟长航时飞行状态下受试者的认知和情绪功能,大脑可能在局部网络层面对睡眠剥夺做出适应性反应,全局网络效率可能下降。 展开更多
关键词 睡眠剥夺 静息态功能磁共振成像 脑功能连接 图论指标
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Uniqueness of Common Fixed Points for a Family of Mappings with <i>Φ</i>-Contractive Condition in 2-Metric Spaces 被引量:9
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作者 Yong-Jie Piao 《Applied Mathematics》 2012年第1期73-77,共5页
In this paper, we will introduce a class of 5-dimensional functions Φ and prove that a family of self-mappings {Ti,j} iεN in 2-metric space have an unique common fixed point if 1) {Ti,j} iεN satisfies Φj-contracti... In this paper, we will introduce a class of 5-dimensional functions Φ and prove that a family of self-mappings {Ti,j} iεN in 2-metric space have an unique common fixed point if 1) {Ti,j} iεN satisfies Φj-contractive condition, where ΦjεΦ, for each jεN;2) Tm,μ n,v for all m,n,μ,vεN with μ ≠ v . Our main result generalizes and unifies many known unique common fixed point theorems in 2-metric spaces. 展开更多
关键词 2-metric Space 5-Dimensional functions Φ Φ-Contractive CONDITION CAUCHY Sequence Common Fixed Point
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Examining the distribution and dynamics of impervious surface in different function zones in Beijing 被引量:6
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作者 乔琨 朱文泉 +3 位作者 胡德勇 郝明 陈姗姗 曹诗颂 《Journal of Geographical Sciences》 SCIE CSCD 2018年第5期669-684,共16页
Impervious surface(IS) is often recognized as the indicator of urban environmental changes. Numerous research efforts have been devoted to studying its spatio-temporal dynamics and ecological effects, especially for t... Impervious surface(IS) is often recognized as the indicator of urban environmental changes. Numerous research efforts have been devoted to studying its spatio-temporal dynamics and ecological effects, especially for the IS in Beijing metropolitan region. However, most previous studies primarily considered the Beijing metropolitan region as a whole without considering the differences and heterogeneity among the function zones. In this study, the subpixel impervious surface results in Beijing within a time series(1991, 2001, 2005, 2011 and 2015) were extracted by means of the classification and regression tree(CART) model combined with change detection models. Then based on the method of standard deviation ellipse, Lorenz curve, contribution index(CI) and landscape metrics, the spatio-temporal dynamics and variations of IS(1991, 2001, 2011 and 2015) in different function zones and districts were analyzed. It is found that the total area of impervious surface in Beijing increased dramatically during the study period, increasing about 144.18%. The deflection angle of major axis of standard deviation ellipse decreased from 47.15° to 38.82°, indicating the major development axis in Beijing gradually moved from northeast-southwest to north-south. Moreover, the heterogeneity of impervious surface’s distribution among 16 districts weakened gradually, but the CI values and landscape metrics in four function zones differed greatly. The urban function extended zone(UFEZ), the main source of the growth of IS in Beijing, had the highest CI values. Its lowest CI value was 1.79 that is still much higher than the highest CI value in other function zones. The core function zone(CFZ), the traditional aggregation zone of impervious surface, had the highest contagion index(CONTAG) values, but it contributed less than UFEZ due to its small area. The CI value of the new urban developed zone(NUDZ) increased rapidly, and it increased from negative to positive and multiplied, becoming animportant contributor to the rise of urban impervious surface. However, the ecological conservation zone(ECZ) had a constant negative contribution all the time, and its CI value decreased gradually. Moreover, the landscape metrics and centroids of impervious surface in different density classes differed greatly. The high-density impervious surface had a more compact configuration and a greater impact on the eco-environment. 展开更多
关键词 impervious surface landscape metrics classification and regression tree(CART) function zones Lorenz curve contribution index
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Block-Based Steganographic Algorithm Using Modulus Function and Pixel-Value Differencing 被引量:1
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作者 Ahlam K. Al-Dhamari Khalid A. Darabkh 《Journal of Software Engineering and Applications》 2017年第1期56-77,共22页
The main purpose in developing the steganographic algorithms lies in achieving most of the steganographic objectives which comprise the embedding capacity, imperceptibility, security, robustness and complexity. In thi... The main purpose in developing the steganographic algorithms lies in achieving most of the steganographic objectives which comprise the embedding capacity, imperceptibility, security, robustness and complexity. In this paper, we propose a high quality steganographic algorithm using new block structure which makes a good use of both modulus function and pixel-value differencing, namely, MF-PVD. We have made many experiments with various test images from several galleries, such as USC-SIPI and UWATERLOO-LINK. The performance of our proposed algorithm is verified using three different performance metrics which include peak signal-to-noise ratio (PSNR), structural similarity index measure (SSIM), and embedding capacity (EC). Experimental results and comparisons with six pertinent state-of-art algorithms are given to prove the validation and efficiency of the proposed algorithm. 展开更多
关键词 Data Hiding STEGANOGRAPHY WATERMARKING Pixel-Value Differencing MODULUS function Performance metrics
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Dynamic fan-in and fan-out metrics for program comprehension
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作者 王玉英 李青山 +1 位作者 陈平 任春德 《Journal of Shanghai University(English Edition)》 CAS 2007年第5期474-479,共6页
In this paper, an approach to use run-time information to discover knowledge about software systems thus facilitating program comprehension is presented. Some dynamic metrics based on traces of the subject system exec... In this paper, an approach to use run-time information to discover knowledge about software systems thus facilitating program comprehension is presented. Some dynamic metrics based on traces of the subject system execution are proposed. A method of getting these dynamic metrics is introduced, in which instrumentation is implemented by using reflective mechanism based on an open compiler. The system run-time information is captured during the instrumented system running and is then analyzed to get these dynamic metrics. A case study is given to illustrate the use of these dynamic metrics, i.e., identifying critical components of the subject system. These critical components should be focus on user attentions in order to understand the subject system well. 展开更多
关键词 program comprehension dynamic metrics critical components functionality
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A Family of Non-Self Maps Satisfying <i>Φ</i><sub>i</sub>-Contractive Condition and Having Unique Common Fixed Point in Metrically Convex Spaces 被引量:1
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作者 Yongjie Piao Dongzhe Piao 《Advances in Pure Mathematics》 2012年第4期280-284,共5页
Class of 5-dimensional functions Φ was introduced and a convergent sequence determined by non-self mappings satisfying certain Φi-contractive condition was constructed, and then that the limit of the sequence is the... Class of 5-dimensional functions Φ was introduced and a convergent sequence determined by non-self mappings satisfying certain Φi-contractive condition was constructed, and then that the limit of the sequence is the unique com-mon fixed point of the mappings was proved. Finally, several more general forms were given. Our main results gener-alize and unify many same type fixed point theorems in references. 展开更多
关键词 metrically Convex Space 5-Dimensional functions Φ Φi-Contractive CONDITION Common Fixed Point Complete
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A Note on the Selection Expectation and Support Function
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作者 Rigao He 《Advances in Pure Mathematics》 2015年第10期583-586,共4页
In this paper, we prove the relationship between selection expectation and support function by a new method.
关键词 Support function HAUSDORFF metric RANDOM Set SELECTION EXPECTATION
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A Remark on the Uniform Convergence of Some Sequences of Functions
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作者 Guy Degla 《Advances in Pure Mathematics》 2015年第9期527-533,共7页
We stress a basic criterion that shows in a simple way how a sequence of real-valued functions can converge uniformly when it is more or less evident that the sequence converges uniformly away from a finite number of ... We stress a basic criterion that shows in a simple way how a sequence of real-valued functions can converge uniformly when it is more or less evident that the sequence converges uniformly away from a finite number of points of the closure of its domain. For functions of a real variable, unlike in most classical textbooks our criterion avoids the search of extrema (by differential calculus) of their general term. 展开更多
关键词 Sequence of functionS UNIFORM CONVERGENCE metric BOUNDEDNESS
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COMMON FIXED POINT OF GENERALIZED WEAKLY CONTRACTIVE MAPS IN PARTIAL METRIC SPACES 被引量:5
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作者 Vesna COJBAIC RAJIC Stojan RADENOVIC Sunny CHAUHAN 《Acta Mathematica Scientia》 SCIE CSCD 2014年第4期1345-1356,共12页
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
关键词 Common fixed point lower semi-continuous function weak (ψ Ф)-contraction partial metric space
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