NONEMPTY INTERSECTION THEOREMS AND SYSTEM OF GENERALIZED VECTOR EQUILIBRIUM PROBLEMS IN PRODUCT G-CONVEX SPACES

By using an existence theorems of maximal elements for a family of set-valued mappings in G-convex spaces due to the author, some new nonempty intersection theorems for a family of set-valued mappings were established in noncompact product G-convex spaces. As applications, some equilibrium existence theorems for a system of generalized vector equilibrium problems were proved in noncompact product G-convex spaces. These theorems unify, improve and generalize some important known results in literature.

NONEMPTY INTERSECTION THEOREMS AND SYSTEM OF GENERALIZED VECTOR EQUILIBRIUM PROBLEMS IN PRODUCT G-CONVEX SPACES

By using an existence theorems of maximal elements for a family of set-valued mappings in G-convex spaces due to the author, some new nonempty intersection theorems for a family of set-valued mappings were established in noncompact product G-convex spaces. As applications, some equilibrium existence theorems for a system of generalized vector equilibrium problems were proved in noncompact product G-convex spaces. These theorems unify, improve and generalize some important known results in literature.

空间生产理论视域下城市社区学习空间的意义生成机制

打造社区学习空间是建设学习型城市的重要举措,而如何吸引社区学习者融入社区学习空间并与之建立意义联结是社区学习空间运行实践面临的现实问题。空间生产理论提供了以生产和构建为核心特征的社会空间结构分析方法论指导,有助于揭示社区学习空间的意义生成机制。基于空间生产理论的三元辩证空间分析框架,结合以人为主体的空间—行为互动分析方法,对S市5个典型城市社区学习空间中36位社区学习者的半结构化访谈文本进行扎根理论分析发现:城市社区学习空间的意义生成可划分为三个阶段,即缘起于日常生活需求的意义触发阶段,由空间感知、空间认知和空间融入循环促进的意义构建阶段,由关系重构和意义感体验相互促进的意义恒定阶段;同时意义生成的过程性递进来自于社区学习者的内生动力、融入社区学习空间后的延续动力以及与空间的关系稳定后的维系动力。基于该意义生成机制,可通过强化与社区学习者日常生活的联结以触发内生动力,关注社区学习者的空间融入以维持延续动力,赋能社区学习者参与自治运行以强化维系动力,以此提升社区学习空间的运行活力。

不同城市绿地类型碳源/汇的城乡梯度格局--以杭州市为例

探究城市化对绿地空间碳源/汇的空间分布格局的影响,对评估城市生态系统的碳足迹和制定相应的碳收支管理措施具有重要意义。以净生态系统生产力(NEP)做为碳源/汇的反映指标,基于净初级生产力和土壤呼吸估算杭州市主城区绿地碳源/汇的空间分布格局,关注城乡梯度对不同绿地类型碳源/汇水平的作用。基于净初级生产力和土壤呼吸数据综合获得绿地空间NEP,通过土地利用数据和Fragstats软件进行景观格局分析,采用多元线性回归模型和逐步回归模型筛选影响NEP的景观、植被和气象因子,最后利用广义加性模型探讨NEP与各因子之间的关系。此外,分别比较了相同统计过程在不同城乡梯度和不同绿地类型之间的模型差异。结果表明:杭州市绿地空间NEP分布及其影响因子存在显著的城乡梯度与绿地类型差异。2019—2022年杭州市主城区绿地空间,整体表现为碳源,年均NEP为-0.277 kg C m^(-2) a^(-1);其中表现为碳汇的绿地主要分布在杭州市主城区的西部,而碳源绿地主要分布在中部和东部。整体绿地空间的NEP大小与绿地斑块面积、乔木盖度和灌木盖度呈正相关,与灌木物种丰富度和气温呈负相关。NEP随城区、城郊结合部、郊区的城乡梯度逐步增强;城区NEP与乔木盖度呈正相关,与景观多样性和气温呈负相关;城郊结合部NEP与乔木物种丰富度和灌木盖度呈正相关,与绿地斑块密度和气温呈负相关;郊区NEP则与聚集度指数、乔木盖度和灌木盖度呈正相关。公园、农田、自然植被的NEP依次增大并受到不同因素的调控。公园NEP与聚集度指数、乔木盖度和灌木盖度呈正相关,与景观分割指数、灌木物种丰富度和气温呈负相关;农田NEP与聚集度指数和灌木盖度呈正相关,与气温呈负相关;而自然植被NEP则与乔木盖度呈正相关,与景观多样性指数和气温呈负相关。研究进一步揭示了城市化对绿地空间碳源/汇的影响,为城乡碳收支的差异化管理提供了一定的理论和数据支持。

以文化为导向的民族村寨旅游空间生产与价值生成--基于岜沙苗寨的实践

民族村寨是乡土文化的聚宝盆,是传统文化的精髓所在,文化为乡村振兴提供源源不断的精神力量,文化振兴是全面振兴的重要抓手。基于列斐伏尔的空间生产理论,文章探讨以文化为导向的民族村寨旅游空间生产与价值生成,以岜沙苗寨为案例,实证分析民族村寨旅游空间的文化价值生成过程。结果表明:(1)资本与权力是民族村寨旅游空间生产及再生产的重要动力;(2)民族村寨旅游空间呈文化属性,以文化为目标导向的民族村寨旅游空间生产,在本质上是一场文化与空间相互赋予的空间生产实践;(3)文化建构下的民族村寨旅游空间生产实现了文化认同,增强了文化自觉。文章在民族村寨旅游空间生产与文化价值二者间架起一座联结的桥梁,凸显了村民主体价值,为提升村民文化自觉提供思路,利于乡村文化振兴。

Optimal Threshold Determination for the Maximum Product of Spacing Methodology with Ties for Extreme Events

Extreme events are defined as values of the event below or above a certain value called threshold. A well chosen threshold helps to identify the extreme levels. Several methods have been used to determine threshold so as to analyze and model extreme events. One of the most successful methods is the maximum product of spacing (MPS). However, there is a problem encountered while modeling data through this method in that the method breaks down when there is a tie in the exceedances. This study offers a solution to model data even if it contains ties. To do so, an optimal threshold that gives more optimal parameters for extreme events, was determined. The study achieved its main objective by deriving a method that improved MPS method for determining an optimal threshold for extreme values in a data set containing ties, estimated the Generalized Pareto Distribution (GPD) parameters for the optimal threshold derived and compared these GPD parameters with GPD parameters determined through the standard MPS model. The study improved maximum product of spacing method and used Generalized Pareto Distribution (GPD) and Peak over threshold (POT) methods as the basis of identifying extreme values. This study will help the statisticians in different sectors of our economy to model extreme events involving ties. To statisticians, the structure of the extreme levels which exist in the tails of the ordinary distributions is very important in analyzing, predicting and forecasting the likelihood of an occurrence of the extreme event.

NONLINEAR SEMIGROUPS AND DIFFERENTIAL INCLUSIONSIN PROBABILISTIC NORMED SPACES

The purpose of this paper is to introduce and study the semi-groups of nonlinear contractions in probabilistic normed spaces and to establish the Crandall-Liggett's exponential formula for some kind of accretive mappings in probabilistic normed spaces. As applications, these results are utilized to study the Cauchy problem for a kind of differential inclusions with accretive mappings in probabilistic normed spaces.

Riesz bases of multivariate translates for Sobolev space

This paper gives a systematic study of Riesz bases of multivariate translates derived from a fixed compactly supported multivariate function in a Sobolev space.Starting with a multivariate function φ satisfying a very mild condition in Sovolev space Hs(Rd),we provide a necessary and sufficient condition under which {φ(x-n)}n∈Zd is a Riesz basis for span{φ(x-n)}n∈Zd.

Optimal Threshold Determination for Securities Exchange Volumes Using Improved Maximum Product of Spacing Methodology

To Statisticians, the structure of the extreme levels which exist in the tails of the ordinary distributions is very important in analyzing, predicting and forecasting the likelihood of an occurrence of extreme event. Extreme events are defined as values of the event below or above a certain value called threshold. A well chosen threshold helps to identify the extreme levels. Several methods have been used to determine threshold so as to analyze and model extreme events. One of the most successful methods is the maximum product of spacing (MPS). However, there is a problem encountered while modeling data through this method in that the method breaks down when there is a tie in the exceedances. This study offers a solution to model data even when it contains ties. In the study, a method that improved MPS method for determining an optimal threshold for extreme values in a data set containing ties was derived. The Generalized Pareto Distribution (GPD) parameters for the optimal threshold were derived and compared to GPD parameters determined through the standard MPS model. The study improved the standard MPS methodology by introducing the concept of frequency and used Generalized Pareto Distribution (GPD) and Peak over threshold (POT) methods as the basis of identifying extreme values. The improved MPS models and the standard models were applied to Nairobi Securities Exchange (NSE) trading volume data to determine the GPD parameters for different sectors registered in NSE market and their performance compared. It was realized that the improved MPS model performed better than the standard models. This study will help the Statisticians in different sectors of our economy to model extreme events involving ties.

Implicit Variational Inclusions and Algorithms Involving （A, η）-monotone Operators in 2-uniformly Smooth Banach Spaces

This paper deals with a new class of nonlinear set valued implicit variational inclusion problems involving （A, η）-monotone mappings in 2-uniformly smooth Banach spaces. Semi-inner product structure has been used to study the （A, η）-monotonicity. Using the generalized resolvent operator technique and the semi-inner product structure, the approximation solvability of the proposed problem is investigated. An iterative algorithm is constructed to approximate the solution of the problem. Convergence analysis of the proposed algorithm is investigated. Similar results are also investigated for variational inclusion problems involving （H, η）-monotone mappings.

A FIXED POINT APPROACH TO THE STABILITY OF A GENERAL MIXED ADDITIVE-CUBIC EQUATION ON BANACH MODULES

Using a fixed-point method, we establish the generalized Hyers-Ulam stability of a general mixed additive-cubic equation： f（kx ＋ y） ＋ f（kx - y） = kf（x ＋ y） ＋ kf（x - y） ＋ 2f（kx） - 2kf（x） in Banach modules over a unital Banach algebra.

一种基于改进A2DC的机载双基杂波谱补偿方法

机载双基预警雷达目标探测系统具有较高的安全性和稳健的探测性能,但其非理想探测构型会造成杂波的非平稳性。传统自适应角度多普勒补偿(A2DC)方法对每个距离门的杂波数据进行空-时两维谱中心的估计,能够有效地补偿双基杂波因复杂构型引入的非平稳误差。然而,当回波中有较强的目标干扰信号时,自适应角度多普勒补偿方法会错误地估计该距离门杂波信号的空-时中心频率,造成目标信号产生相消现象。针对该问题,文中提出一种基于改进的A2DC的双基杂波谱补偿方法。所提方法将自适应角度多普勒补偿和广义内积法相结合,在杂波非平稳误差初步补偿之后剔除含有“疑似目标”的非均匀距离样本;并用该距离门附近样本的杂波谱中心估计参数构成相应的补偿矩阵,对该距离单元杂波数据进行角度-多普勒域的谱误差精确补偿;最终根据双基杂波非平稳误差精细化补偿后的样本数据,实现地理杂波的有效抑制,且有效避免了动目标信号因空域相消导致信杂噪比严重降低的问题。机载双基雷达杂波抑制和动目标检测的仿真实验结果表明,所提方法在面对多目标信号干扰时具有优良的双基杂波距离依赖补偿效果,从而完成稳健的地理杂波对消和动目标信号的可靠探测。

Maps Preserving Peripheral Spectrum of Generalized Jordan Products of Operators

Let X1 and X2 be complex Banach spaces with dimension at least three, A1 and A2 be standard operator algebras on X1 and X2, respectively. For k ≥ 2, let （i1, i2, . . . , im） be a finite sequence such that {i1, i2, . . . , im} = {1, 2, . . . , k} and assume that at least one of the terms in （i1, . . . , im） appears exactly once. Define the generalized Jordan productT1 o T2 o··· o Tk = Ti1Ti2··· Tim ＋ Tim··· Ti2Ti1 on elements in Ai. This includes the usual Jordan product A1A2 ＋ A2A1, and the Jordan triple A1A2A3 ＋ A3A2A1. Let Φ ： A1 → A2 be a map with range containing all operators of rank at most three. It is shown that Φ satisfies that σπ（Φ（A1） o··· o Φ（Ak）） = σπ（A1 o··· o Ak） for all A1, . . . , Ak, where σπ（A） stands for the peripheral spectrum of A, if and only if Φ is a Jordan isomorphism multiplied by an m-th root of unity.

基于相对马氏距离的非均匀杂波抑制方法

由于天基雷达覆盖范围广、探测背景复杂,雷达回波会呈现出明显的非均匀特性,从而导致杂波协方差矩阵(clutter covariance matrix,CCM)估计与实际情况出现偏差,从而恶化天基雷达对空中动目标的检测性能。针对上述问题,提出了一种基于相对马氏距离的非均匀样本抑制方法,该方法首先计算所有样本的广义内积(generalized inner product,GIP),在此基础上选取一个合适的样本作为参考。通过比较场景中所有样本与参考样本的马氏距离,将相对马氏距离大于判定门限的样本作为非均匀样本剔除。用筛选后的样本进行杂波协方差矩阵估计,从而提高天基雷达在复杂环境下对空中动目标的检测性能。理论分析和实测数据结果表明,所提算法能够在非均匀环境下有效检测出空中动目标。

On Wick product of generalized operators

Fundamental properties of Wick product of generalized operators are investigated. The annihilation and creation algebras are characterized from various points of view. Wick ordering widely used in quantum physics is interpreted as the Wick product of generalized operators.

空时自适应处理中基于知识的训练样本选择策略

针对空时自适应处理中样本协方差矩阵受干扰目标污染时检测性能下降的问题,提出了一种基于知识的空时自适应处理(knowledge aided space time adaptive processing,KA-STAP)方法。该方法将待测距离单元杂波的先验知识与广义内积非同态检测器(general inner product nonhomogeneity detector,GIP NHD)结合,对训练样本进行有效选择。通过仿真证明该方法能有效剔除存在干扰目标的样本,提高训练样本被干扰目标污染时空时自适应处理的检测性能。

基于广义极值分布的设计波高推算

简介了广义极值分布函数及其3种参数估计方法,包括极大似然(ML)、线性矩(LM)和间隔最大积(MPS)估计的计算方法。使用广义极值分布函数推算了北部湾涠洲岛海域3个波向的年波高极值序列设计波高,并与Weibull分布、Gumbel分布和皮尔逊Ⅲ型分布的推算结果加以对比。分析表明,涠洲岛海域极值波高服从于广义极值Ⅲ型分布,拟合优度检验结果表明广义极值分布能更好地拟合极值波高;MPS方法是一种优良的参数估计法,推算的设计波高可作为海岸环境工程设计的首要参考值。

Lfuzzy拓扑空间的相对乘积空间与ST_i分离性(i=1,2)

就STi(i =1 ,2 )分离性 ,讨论了L fuzzy拓扑空间的相对乘积运算中的可乘性问题 .

关于随机赋范空间与随机内积空间的某些基本理论(英文)

首先提出随机度量空间定义的另一个提法，这提法不仅等价于原始的定义而且也使随机度量空间自动归入广义度量空间的框架，也考虑了关于拓扑结构的某些新的问题；循着同样的思路，对随机赋范空间的定义也作了新的处理并同时简化了随机赋范模的定义．其次本文也证明了一个Ｅ－范空间的商空间等距同构于一个典型的Ｅ－范空间；进一步，在概率赋范空间的框架下证明了一个概率赋伪范空间是伪内积生成空间的充要条件是它等距同构于一个Ｅ－内积空间，这回答了Ｃ．Ａｌｓｉｎａ与Ｂ．Ｓｃｈｗｅｉｚｅｒ等人新近提出的公开问题．最后，本文转向了它的中心部分──关于随机内积空间的研究，对随机内积空间中的特有且复杂的正交性作较系统的讨论，论证了只有几乎处处正交性才是唯一合理的正交性概念，在此基础上本文尤其将Ｇ．Ｓｔａｍｐａｃｃｈｉａ的在众多学科中都有多种用途的一般投影定理（或称变分不等式解存在性定理）以适当形式推广到完备实随机内积模上．

非正弦电路广义功率和特征参数的定义

将多相电压和电流函数定义为Hibert内积空间的2个向量，并应用正交投影定理对电流向量作正交分解，在此基础上给出了普遍适用的广义功率及其特征参数的定义表达式，并讨论了它们的性质。