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1.
关于非交换子空间格代数的超自反性   总被引:1,自引:0,他引:1  
赵君喜  马吉溥 《数学学报》1996,39(6):721-727
利用Arveson关于自反代数超自反的特征,给出Hilbert空间上一类非交换格自反代数超自反常数的一个估计,证明了一些非交换子空间格自反代数的超自反性.  相似文献   

2.
本文讨论了子空间格的自反性和超自反性,给出了子空间格是超自反的等价条件.  相似文献   

3.
李建奎 《数学研究》1997,30(2):151-156
研究了算子子空间的渐近自反性问题,渐近自反子空间的遗传斯近自反性以及某些单个算子的渐近自反性.我们也讨论了投影网类的浙近自反性。  相似文献   

4.
自反Banach空间上算子代数的超自反性   总被引:4,自引:0,他引:4  
袁国常 《数学杂志》2003,23(1):78-84
本文引入自发Banach空间上算子代数A的超自反定义,讨论了A超自反的充要条件,超自反常数的估计以及超自反在代数同构下的不变性。  相似文献   

5.
关于超自反算子代数   总被引:1,自引:1,他引:0  
曹怀信 《数学杂志》1993,13(4):534-540
本文讨论了超自反算子代数的等价条件及超自反性在张量积、直和、同构、约化中的不变性,改进加深了孙善利^[2]的结果,并证明了两类Von Neumann代数的超自反性。  相似文献   

6.
郭育红  王汝军 《数学学报》2016,59(4):535-544
首先,给出了偶数2v的自反的n-color有序分拆与v+1,v-1的n-color有序分拆之间的一个组合双射,并利用相应的计数公式得到了一个组合恒等式.其次,给出了正整数自反的n-color有序分拆数与Fibonacci数、Lucas数之间的一个关系式,并利用此关系式给出了偶数与奇数的自反的n-color有序分拆之间的一个组合双射.最后,给出了一些涉及正整数v的自反的n-color有序分拆数与其它有约束条件的有序分拆数之间的分拆恒等式.  相似文献   

7.
证明了自反Banach空间X中自反代数A到B(x)的导子集合是拓扑代数双自反的.  相似文献   

8.
韩德广 《数学杂志》1991,11(1):119-119
本文总假定 H 是可分的 Hilbert 空间;L(H)表示 H 上有界线性算子全体;而 L(?)(H)表示 L(H)上σ-ω算子拓扑连续的线性泛函全体.设(?)L(H)为σ-ω算子拓扑闭的子代数,(?)称为自反的是指(?)=Alg Lat(?)={T∈L(H):TE(?)E (?)E∈Lat(?)},其中 Lat(?)是(?)的不变子空间格.(?)称为超自反的是指存在常数 K>0,使对任意的 T∈L(H)有 d(T,(?))≤K sup{‖P_M~(?)TP_M‖∶M∈Lat(?)}.其中 P_M 是指到 M 上的自伴投影。有关算子代数的超自反性已有一些结果,例如见  相似文献   

9.
本文对B(X,Y)的自反子空间及渐近自反子空间上的映射(或映射组),分别给出了一些判别它们的图象(或联合图象)仍为自反及渐近自反的方法。  相似文献   

10.
设A是B(X)的子代数,且A具有分离向量x0,本文讨论它的2-自反性和亚自反性,并就具有分离向量的交换算子代数.部分地回答了J.A.Deddens在文献[7]中提出的一些关于自反性的问题.  相似文献   

11.
李鹏  李洪波  王娟 《运筹与管理》2020,29(10):84-91
融合就业是残疾人可持续发展的关键途径。基于演化博弈理论和残疾人就业促进政策,建立残疾人与用人单位(企业)行为交互过程的动态演化模型,用数值实验展示了初始条件改变和决策变量不同取值对系统演化结果的影响。研究发现,残疾人就业行为路径演化系统收敛于良好状态和“锁定”状态两种模式;调控模型中的参数收敛于不同模式的概率发生显著变化或变化不明显,揭示了现实中残疾人就业治理效果不理想的深层次原因;通过提高残疾人的工资待遇、心理收益、为企业创造的价值,减少残疾人的社会补助与就业付出的人力和社会资本,增加残疾人就业法定比例、企业雇佣残疾人的声誉收益、增值税退税优惠(企业符合退税条件)与雇佣残疾人数量,减少企业支持残疾人的就业投入等均能使系统演化到良好状态的概率增加。这为制定灵活有效的残疾人就业制度、政策与措施提供了较大的操作空间,多元主体协同治理,利益共享,良性互动,以跳出不良“锁定”状态,实现残疾人就业行为良序发展,破解就业难题。  相似文献   

12.
We investigate an AB system, which can be used to describe marginally unstable baroclinic wave packets in a geophysical fluid. Using the generalized Darboux transformation, we obtain higher-order rogue wave solutions and analyze rogue wave propagation and interaction. We obtain bright rogue waves with one and two peaks. For the wave packet amplitude and the mean-flow correction resulting from the self-rectification of the nonlinear wave, the positions and values of the wave crests and troughs are expressed in terms of a parameter describing the state of the basic flow, in terms of a parameter responsible for the interaction of the wave packet and the mean flow, and in terms of the group velocity. We show that the interaction of the wave packet and mean flow and also the group velocity affect the propagation and interaction of the amplitude of the wave packet and the self-rectification of the nonlinear wave.  相似文献   

13.
在其深层次机理上,港口物流系统竞争能力必受其物质技术支撑体系的制约.结合智慧港口和第五代港口基本理论,可得出深层次物质技术支撑体系主要有:物质资源禀赋、城市经济系统、物联网系统、港口经营系统、绿色效率系统等.以相关港口物流系统竞争力基本理论为指导,考虑到中国各港口的实际情况,结合数据获得的难易程度,分别从基础设施、发展环境、智慧技术、服务水平、低碳绩效五个方面遴选出18个评价指标,按照模糊信息熵理论,利用全国24个主要港口2001—2013年的原始数据,通过数学软件Matlab编程,计算出系统层指标的信息熵和权重及全国8个代表性港口2013年的竞争能力综合评价值,并以福建省福州港为例,对其进行横向比较和纵向时序分析.  相似文献   

14.
项目投资与融资匹配程度,不仅关系到项目资金成本的大小,还体现对项目利率风险的对冲。基于债券久期的概念内涵,提出了项目久期与融资结构久期的概念及计算方法。以具体项目的投融资为案例进行研究,对案例公司已拟定的针对独立项目的债券融资方案进行投融资久期匹配、各期现金流匹配评价,并从市场利率曲线中发现融资成本优化空间,从投融资久期差及各期投融资现金流量差中找到优化融资的方案。以此提出结论:项目久期与融资结构久期的匹配是降低项目利率风险的重要手段;应综合融资结构久期与项目久期、现金流大小选择融资结构。  相似文献   

15.
A combination of the Busemann ellipse, the inscribed unit circle and a circle of radius √2 about the same centre is considered. For supersonic two-dimensional potential gas flows, it is shown that the inclinations of the velocity vector in motion along an arbitrary characteristic, the characteristic itself and the characteristic of the other family have values equal to, respectively. the difference between the areas of the elliptical and circular (R = 1) sectors, the difference between the areas of the elliptical and circular (R = √2) sectors, and the area of the elliptical sector, apart from unimportant multiplicative and additive constants. The straight sides of the sectors in question are the semiminor antis of the ellipse and the radius vector of the velocity. The obvious analogy with one of Ke:pler's laws is pointed out. The existence of a point of intersection of the ellipse and the second circle illustrates a well-known result of Khristianovich concerning the points of inflexion of characteristics with a monotone velocity distribution. It is shown how the combination of the ellipse and the inscribed circle illustrates the simplification of the compatibility conditions and the Darboux equation for trans- and hypersonic flows.  相似文献   

16.
针对乡村绿色生态旅游特征,并考虑旅游者个体感受与群体效益,本文从乡村绿色生态旅游开发与适宜评级概念出发,提出乡村绿色生态旅游适宜等级VIKOR评估模型与方法。首先,从等级评估的概念与内涵出发,刻画乡村绿色生态旅游适宜评级问题,避免混淆旅游适宜评级和排序两个本质不同的问题。然后,构建乡村绿色生态旅游适宜等级评估指标及隶属函数,提出评估指标的熵权确定方法。其次,提出乡村绿色生态旅游适宜等级VIKOR评估模型与二元语义等级评估方法。最后,通过案例研究和比较分析,说明本文所提模型与方法的合理性、可行性与实用性。  相似文献   

17.
在气候变化应对日益紧迫的背景下,研究了政府、企业、研发机构和金融机构(政产学研金)参与低碳环境友好技术(LCEFT)创新的条件和策略。以企业合作关系为假设条件,引入金融主体和科研机构,构建了LCEFT的政产学研金协调创新博弈模型,深入分析了碳权质押、信用等级、投资回报等因素对博弈系统群体协调创新策略的影响。研究表明,金融机构参与协同创新的决策受到政府奖惩机制、绿色信贷项目盈利和风险等因素的影响;多主体在资源和能力上的互补性正是LCEFT协同创新联盟形成的关键;政府部门的奖惩机制能够促进多主体合作,但难以使得整体获得最优,达到整体最优的关键是有效地发挥政府部门的引导作用和金融机构的杠杆作用。本文为政府部门制定绿色金融、产学研协同创新及产业化管理机制提供了新思路和一定的决策参考。  相似文献   

18.
社会评价模型研究   总被引:4,自引:0,他引:4  
阮守武  梁樑 《运筹与管理》2005,14(4):147-153
本文利用社会选择理论、行为理论和委托代理理论的基本原理和方法采用模型化的方式研究社会评价,分析了我国在权威机构评价方面存在的误区及其形成的原因,对我国社会评价的实现途径和制度创新问题进行了探讨。  相似文献   

19.
Many location problems may be separated into a series of interrelated macro, meso and micro decision-making states. The macro scale decision determines the type, capacity and number of facilities, the meso scale decision determines the location and allocation of facilities and the micro scale decision determines such considerations as routing and scheduling of service vehicles. This paper concerns the first two levels of decision-making.The present paper demonstrates the use of two models: (i) an analytical model that uses continuum approximations and methods of calculus to determine the number of facilities, the capacity and the approximate location of each that minimizes the sum of the transportation and facility costs for a slowly varying demand rate, and (ii) a traditional location-allocation model that determines more exactly the resulting locations and allocations. These two approaches have specific requirements in terms of data input, cost of data collection and cost of solution and, consequently, yield unique insights and benefits for practising planners. The strengths and weaknesses of the two models are complementary. This thesis is developed with an analysis of the Calgary, Alberta refuse collection and disposal system.  相似文献   

20.
We propose a thermodynamic method and a statistical one for constructing the constitutive equations of elastoviscoplastic deformation and strengthening of materials. The thermodynamic method is based on the energy conservation law as well as the equations of entropy balance and entropy generation in the presence of self-equilibrated internal microstresses, which are characterized by coupled strengthening parameters. The general constitutive equations consist of the relations between thermodynamic flows and forces, which follow from nonnegativity of entropy generation and satisfy the generalized Onsager principle, as well as the thermoelasticity relations and the expression for entropy, which follow from the energy conservation law. The specific constitutive equations are obtained on the basis of representation of the energy dissipation rate as a sum of two constituents that describe translational and isotropic strengthening and are approximated by power and hyperbolic sine laws. Starting from the stochastic microstructural concepts, we construct the constitutive equations of elastoviscoplastic deformation and strengthening on the basis of the linear model of thermoelasticity and the nonlinear Maxwell model for spherical and deviatoric components of microstresses and microstrains, respectively. The solution of the problem of the effective properties and stress-strain state of a three-component material is constructed with the use of the combined Voigt–Reuss scheme and leads to constitutive equations coinciding, as to their form, with similar equations constructed by the thermodynamic method.  相似文献   

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