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华北地区棉田翻压冬绿肥腐解及养分释放规律研究 被引量:42
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作者 宁东峰 马卫萍 +3 位作者 孙文彦 李志杰 王来清 曹卫东 《华北农学报》 CSCD 北大核心 2011年第6期164-167,共4页
利用尼龙网袋,研究了油菜、毛叶苕子、冬牧70黑麦翻压于棉花田间15~20 cm土层,腐解及养分释放规律。研究表明,绿肥翻压43 d内干物重显著降低,前3 d腐解速度最快,后降低趋势变缓。翻压43 d时油菜、毛叶苕子、冬牧70黑麦腐解率达到81.7%,... 利用尼龙网袋,研究了油菜、毛叶苕子、冬牧70黑麦翻压于棉花田间15~20 cm土层,腐解及养分释放规律。研究表明,绿肥翻压43 d内干物重显著降低,前3 d腐解速度最快,后降低趋势变缓。翻压43 d时油菜、毛叶苕子、冬牧70黑麦腐解率达到81.7%,77.5%,62.2%;翻压113 d时腐解率分别达到89.6%,89.5%,76.2%。翻压21d内氮释放较快,3个品种氮矿化率都达到60%以上。磷在整个翻压期内释放较为平缓,翻压113 d时油菜、毛叶苕子、冬牧70黑麦磷矿化率分别达到89.6%,86.5%,75.6%。钾在翻压前期迅速释放,翻压9 d后,油菜、毛叶苕子、冬牧70黑麦钾的矿化率分别为94.5%,93.2%,91.9%。翻压前21 d,绿肥碳含量显著降低,以后逐渐缓慢,翻压113 d后油菜、毛叶苕子、冬牧70黑麦碳矿化率为93.4%,91.3%,81.9%。在翻压前15 d,冬牧70黑麦C/N呈上升趋势,其他两品种C/N变化不显著。 展开更多
关键词 冬牧70黑麦 冬油菜 毛叶苕子 腐解规律 养分释放特征
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COHERENT, REGULAR AND SIMPLE SYSTEMS IN ZERO DECOMPOSITIONS OF PARTIAL DIFFERENTIAL SYSTEMS 被引量:7
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作者 LI Ziming(Institute Of Algorithms and Scientific Computing, German National Research Centerfor Information Technology, D-52754 Sankt Augustin, Germany)WANG Dongming(LEIBNIZ-IMAG, 46, Avenue Felix Viallet,38031 Grenoble Cedex, France) 《Systems Science and Mathematical Sciences》 SCIE EI CSCD 1999年第S1期43-60,共18页
This paper studies triangular differential systems arising from various decompositions of partial differential polynomial systems. In theoretical aspects, we emphasizeon translating differential problems into purely a... This paper studies triangular differential systems arising from various decompositions of partial differential polynomial systems. In theoretical aspects, we emphasizeon translating differential problems into purely algebraic ones. Rosenfeld’s lemma is extended to a more general setting; relations between passivity and coherence are clarified;regular systems and simple systems are generalized and proposed, respectively. In algorithmic aspects, we review the Ritt-Wu and Seidenberg algorithms, and outline a methodfor decomposing a differential polynomial system into simple ones. Some applications arealso discussed. 展开更多
关键词 COHERENT set geometric theorem proving irreducible TRIANGULAR SYSTEM partial differential polynomial SYSTEM regular SYSTEM SIMPLE SYSTEM TRIANGULAR SYSTEM ZERO decomposition.
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边界约束二次规划问题的分解方法 被引量:6
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作者 卢战杰 魏紫銮 《计算数学》 CSCD 北大核心 1999年第4期475-482,共8页
A Decomposition method for solving quadratic programming (QP) with boxconstraints is presented in this paper. It is similar to the iterative method forsolving linear system of equations. The main ideas of the algorith... A Decomposition method for solving quadratic programming (QP) with boxconstraints is presented in this paper. It is similar to the iterative method forsolving linear system of equations. The main ideas of the algorithm are to splitthe Hessian matrix Q of the oP problem into the sum of two matrices N and Hsuch that Q = N + H and (N - H) is symmetric positive definite matrix ((N, H)is called a regular splitting of Q)[5]. A new quadratic programming problem withHessian matrix N to replace the original Q is easier to solve than the originalproblem in each iteration. The convergence of the algorithm is proved under certainassumptions, and the sequence generated by the algorithm converges to optimalsolution and has a linear rate of R-convergence if the matrix Q is positive definite,or a stationary point for the general indefinite matrix Q, and the numerical resultsare also given. 展开更多
关键词 分解方法 二次规划 正则分裂 边界约束 收敛性
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确定性信号分解与平稳随机信号分解的统一研究 被引量:8
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作者 王宏禹 邱天爽 《通信学报》 EI CSCD 北大核心 2016年第10期1-8,共8页
对确定性信号分解与平稳随机信号分解进行了深入统一的研究。首先根据线性系统稳定性理论,分别给出正则稳定情况下与边界稳定情况下2种信号分解的统一研究结果。然后根据线性空间投影理论,分别给出正交投影情况下与自投影情况下2种信号... 对确定性信号分解与平稳随机信号分解进行了深入统一的研究。首先根据线性系统稳定性理论,分别给出正则稳定情况下与边界稳定情况下2种信号分解的统一研究结果。然后根据线性空间投影理论,分别给出正交投影情况下与自投影情况下2种信号分解的统一研究结果。前一种研究明确具体且物理意义清晰,后一种研究数学意义与几何意义清晰,将两者合在一起研究,相得益彰。 展开更多
关键词 信号分解 线性系统 正则稳定 边界稳定 线性空间 正交投影 自投影
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5-正则图的路分解
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作者 初亚男 范更华 +1 位作者 洪明珠 周垂香 《中国科学:数学》 CSCD 北大核心 2024年第11期1787-1794,共8页
对于正则图的路分解问题,Favaron等(2010)提出猜想:对于奇数l,任意包含一个完美匹配的l-正则图可以分解成长度为l的路.当l=5时,Favaron等(2010)证明了不含4-圈时猜想成立.后来Botler等(2015)证明了不含3-圈时猜想成立.本文证明当l=5且... 对于正则图的路分解问题,Favaron等(2010)提出猜想:对于奇数l,任意包含一个完美匹配的l-正则图可以分解成长度为l的路.当l=5时,Favaron等(2010)证明了不含4-圈时猜想成立.后来Botler等(2015)证明了不含3-圈时猜想成立.本文证明当l=5且图中任意3-圈与4-圈的交为空集时,猜想成立. 展开更多
关键词 分解 正则图
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DG Hosting Capacity Assessment Considering Dependence Among Wind Speed,Solar Radiation,and Load Demands
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作者 Junyi Yang Jiangmin Bao +3 位作者 Yuhan Hou Han Wu Qiang Li Yue Yuan 《CSEE Journal of Power and Energy Systems》 SCIE EI CSCD 2024年第3期1011-1025,共15页
Dependence of distributed generation(DG)outputs and load plays an essential role in renewable energy accommodation.This paper presents a novel DG hosting capacity(DGHC)evaluation method for distribution networks consi... Dependence of distributed generation(DG)outputs and load plays an essential role in renewable energy accommodation.This paper presents a novel DG hosting capacity(DGHC)evaluation method for distribution networks considering highdimensional dependence relations among solar radiation,wind speed,and various load types(i.e.,commercial,residential,and industrial).First,an advanced dependence modeling method called regular vine(R-vine)is applied to capture the complex dependence structure of solar radiation,wind speed,commercial loads,industrial loads,and residential loads.Then,a chanceconstrained DGHC evaluation model is employed to figure out maximum hosting capacity of each DG and its optimal allocation plan with different operational risks.Finally,a Benders decomposition algorithm is also employed to reduce computational burden.The proposed approaches are validated using a set of historical data from China.Results show dependence among different DGs and loads has significant impact on hosting capacity.Results also suggest using the R-vine model to capture dependence among distributed energy resources(DERs)and load.This finding provides useful advice for distribution networks in installing renewable energy generations. 展开更多
关键词 Benders decomposition correlation DG hosting capacity regular vine
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REGULAR CONTRACTIONS IN Ⅱ SPACE
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作者 严绍宗 《Chinese Science Bulletin》 SCIE EI CAS 1989年第9期710-713,共4页
The concept of the regular contractions was introduced in [1], and it was proved that there must be the unitary dilations for regular contractions in Halmos or Nagy sense, consequently, the conjugate operator of a reg... The concept of the regular contractions was introduced in [1], and it was proved that there must be the unitary dilations for regular contractions in Halmos or Nagy sense, consequently, the conjugate operator of a regular contraction is also a 展开更多
关键词 regular decomposition regular contraction.
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Characteristic Decomposition: From Regular Sets to Normal Sets 被引量:1
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作者 MOU Chenqi WANG Dongming 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2019年第1期37-46,共10页
In this paper it is shown how to transform a regular triangular set into a normal triangular set by computing the W-characteristic set of their saturated ideal and an algorithm is proposed for decomposing any polynomi... In this paper it is shown how to transform a regular triangular set into a normal triangular set by computing the W-characteristic set of their saturated ideal and an algorithm is proposed for decomposing any polynomial set into ?nitely many strong characteristic pairs, each of which is formed with the reduced lexicographic Gr?bner basis and the normal W-characteristic set of a characterizable ideal. 展开更多
关键词 CHARACTERISTIC decomposition CHARACTERISTIC PAIR NORMAL SET regular SET W-characteristic SET
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Partial expansion of a Lipschitz domain and some applications
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作者 Jay Gopalakrishnan Weifeng Qiu 《Frontiers of Mathematics in China》 SCIE CSCD 2012年第2期249-272,共24页
We show that a Lipschitz domain can be expanded solely near a part of its boundary, assuming that the part is enclosed by a piecewise C1 curve. The expanded domain as well as the extended part are both Lipschitz. We a... We show that a Lipschitz domain can be expanded solely near a part of its boundary, assuming that the part is enclosed by a piecewise C1 curve. The expanded domain as well as the extended part are both Lipschitz. We apply this result to prove a regular decomposition of standard wector Sobolev spaces with vanishing traces only on part of the boundary. Another application in the construction of low-regularity projectors into finite element spaces with partial boundary conditions is also indicated. 展开更多
关键词 Lipschitz domain regular decomposition mixed boundary condition transversal vector field extension operator Schwarz preconditioner bounded cochain projector divergence CURL SchSberl projector
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ON THE ASCENDING SUBGRAPH DECOMPOSITIONS OF REGULAR GRAPHS
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作者 CHENHUAITANG MAKEJIE 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1998年第2期165-170,共6页
The definition of the ascending subgraph decomposition was given by Alavi. It has been conjectured that every graph of positive size has an ascending subgraph decomposition. In this paper it is proved that the regular... The definition of the ascending subgraph decomposition was given by Alavi. It has been conjectured that every graph of positive size has an ascending subgraph decomposition. In this paper it is proved that the regular graphs under some conditions do have an ascending subgraph decomposition. 展开更多
关键词 Ascending subgraph decomposition regular graph induced subgraph
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ON SPINODAL BOUNDARIES OF Al-Li ALLOYS
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《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1995年第1期41-46,共6页
The spinodal decomposition can occur in Al-Li alloys containing 5.8-14.2 at.% Li at room temperature. The modutated structure wavelength is approximately 3.1 nm for com mercial Al-LI alloys. The limit composition of t... The spinodal decomposition can occur in Al-Li alloys containing 5.8-14.2 at.% Li at room temperature. The modutated structure wavelength is approximately 3.1 nm for com mercial Al-LI alloys. The limit composition of the miscibility gap is 3.66 -16.06 at.%Li at 298 K. The highest temperature of the miscibility gap is 377 K. 展开更多
关键词 Al-Li alloy spinodal decomposition regular solution
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批到达M/G/1重试排队的队长的尾渐近
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作者 王颖俐 刘维奇 李继红 《运筹学学报》 CSCD 北大核心 2013年第1期29-37,共9页
用随机分解法研究成批到达服务时间为次指数分布的重试排队中队长的尾行为,得到了该系统与其相应的标准排队系统队长尾分布的关系;对次指数尾,结果也能用于正则变化尾,进而得到正则变化尾渐近.
关键词 重试排队 尾渐近 随机分解 次指数 正则变化
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Meshless Method with Domain Decomposition for Submerged Porous Breakwaters in Waves
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作者 CHIOUKH Nadji YÜKSEL Yalçın 《Journal of Ocean University of China》 SCIE CAS CSCD 2021年第6期1325-1340,共16页
Based on the improved version of the meshless singular boundary method(ISBM)in multi domain(MD),a numerical method is proposed in this paper to study the interaction of submerged permeable breakwaters and regular wave... Based on the improved version of the meshless singular boundary method(ISBM)in multi domain(MD),a numerical method is proposed in this paper to study the interaction of submerged permeable breakwaters and regular waves at normal incidence.To account for fluid flow inside the porous breakwaters,the conventional model of Sollitt and Cross for porous media is adopted.Both single and dual trapezoidal breakwaters are examined.The physical problem is formulated in the context of the linear potential wave theory.The domain decomposition method(DDM)is employed,in which the full computational domain is decomposed into separate domains,that is,the fluid domain and the domains of the breakwaters.Respectively,appropriate mixed type boundary and continuity conditions are applied for each subdomain and at the interfaces between domains.The solution is approximated in each subdomain by the ISBM.The discretized algebraic equations are combined,resulting in an overdetermined full system that is solved using a least-square solution procedure.The numerical results are presented in terms of the hydrodynamic quantities of reflection,transmission,and wave-energy dissipation.The relevance of the results of the present numerical procedure is first validated against data of previous studies,and then selected computations are discussed for various structural conditions.The proposed method is demonstrated to be highly accurate and computationally efficient. 展开更多
关键词 meshless method domain decomposition regular waves BREAKWATERS POROSITY reflection transmission DISSIPATION coastal environment
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正则与简单系统算法的优化
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作者 金萌 《山东大学学报(理学版)》 CAS CSCD 北大核心 2010年第12期106-111,共6页
改进王东明提出的正则系统算法(简称RegSer算法)及简单系统算法(简称SimSer算法)的效率。提出新的分解策略:对于任意多项式系统或多项式组[P,Q],首先计算一组良好三角系统,得到[P,Q]的一种零点分解。其次判断每一良好系统是否是正则系统... 改进王东明提出的正则系统算法(简称RegSer算法)及简单系统算法(简称SimSer算法)的效率。提出新的分解策略:对于任意多项式系统或多项式组[P,Q],首先计算一组良好三角系统,得到[P,Q]的一种零点分解。其次判断每一良好系统是否是正则系统,若不是则将其正则化,即计算一组正则系统,给出该良好系统的零点分解。最后将每一正则系统简单化,即计算一组简单系统,给出该正则系统的零点分解,得到给定多项式系统或多项式组的简单分解。实验结果表明这种分解策略可以提高RegSer和SimSer算法的效率。 展开更多
关键词 算法 三角分解 正则系统 简单系统 MAPLE
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一般二次规划的一种分解算法
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作者 孙培培 《甘肃联合大学学报(自然科学版)》 2008年第4期27-31,共5页
提出了求解一般二次规划问题的一种分解迭代算法.算法的主要思想是对问题的Hessian矩阵G进行正则分裂,即G=N+H并且满足N-H是正定的.在每次迭代中用一个易于求解的矩阵N代替G进行计算.在矩阵G是正定的条件下,算法具有线性收敛性质,产生... 提出了求解一般二次规划问题的一种分解迭代算法.算法的主要思想是对问题的Hessian矩阵G进行正则分裂,即G=N+H并且满足N-H是正定的.在每次迭代中用一个易于求解的矩阵N代替G进行计算.在矩阵G是正定的条件下,算法具有线性收敛性质,产生的迭代点列收敛到原问题的最优解.当矩阵G不正定时,算法产生的点列收敛到问题的稳定点. 展开更多
关键词 二次规划 分解算法 正则分裂 收敛
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利用地质规则块体建模方法的频率域有限元弹性波速度反演 被引量:15
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作者 许琨 王妙月 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2004年第4期708-717,共10页
在频率域弹性波有限元正演方程的基础上 ,依据匹配函数 (也就是观测数据和正演数据残差的二次范数 )最小的准则 ,用矩阵压缩存储与LU分解技术来存储和求解频率域正演方程中的大型稀疏复系数矩阵、用可调阻尼因子的Levenberg Marquard方... 在频率域弹性波有限元正演方程的基础上 ,依据匹配函数 (也就是观测数据和正演数据残差的二次范数 )最小的准则 ,用矩阵压缩存储与LU分解技术来存储和求解频率域正演方程中的大型稀疏复系数矩阵、用可调阻尼因子的Levenberg Marquard方法求解反演方程组 ,直接求取地下介质的弹性波速度 ,导出了频率域弹性波有限元最小二乘反演算法 .为了利用地下地质体的分布规律 ,减少反演所求的未知数个数 ,本文又提出了规则地质块体建模方法引入到反演中来 .经数值模型验证 ,在噪声干扰很大 (噪声达到 5 0 % )或初始模型与真实模型相差很大的情况下 ,反演也能取得很满意的效果 ,证明本方法具有很好的抗噪性与“强壮性” . 展开更多
关键词 频率域 弹性波 有限元 反演 矩阵压缩存储 LU分解技术 Levenberg-Marquard方法 地质规则块 体建模方法
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基于过完备字典的缺失振动数据压缩感知重构算法 被引量:10
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作者 余路 曲建岭 +2 位作者 高峰 田沿平 申江江 《系统工程与电子技术》 EI CSCD 北大核心 2017年第8期1871-1877,共7页
针对振动数据采集过程中由于设备短路或环境变化等诸多因素导致的数据丢失问题,提出了一种基于过完备字典的缺失振动数据压缩感知重构算法。首先利用K-奇异值分解算法对大量振动数据进行字典学习得到过完备字典,然后构建缺失振动数据的... 针对振动数据采集过程中由于设备短路或环境变化等诸多因素导致的数据丢失问题,提出了一种基于过完备字典的缺失振动数据压缩感知重构算法。首先利用K-奇异值分解算法对大量振动数据进行字典学习得到过完备字典,然后构建缺失振动数据的采样矩阵作为压缩感知框架下的测量矩阵。最后利用正则化正交匹配追踪算法完成缺失数据的重构。通过振动数据库数据和实测航空发动机振动数据实验表明,所提算法优于传统基于离散余弦变换和离散傅里叶变换的数据修复算法,同时具有一定的鲁棒性。 展开更多
关键词 字典学习 K-奇异值分解 压缩感知 振动数据修复 正则化正交匹配追踪
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Generic Regular Decompositions for Parametric Polynomial Systems 被引量:2
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作者 CHEN Zhenghong TANG Xiaoxian XIA Bican 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2015年第5期1194-1211,共18页
This paper presents a generalization of the authors' earlier work. In this paper, the two concepts, generic regular decomposition (GRD) and regular-decomposition-unstable (RDU) variety introduced in the authors'... This paper presents a generalization of the authors' earlier work. In this paper, the two concepts, generic regular decomposition (GRD) and regular-decomposition-unstable (RDU) variety introduced in the authors' previous work for generic zero-dimensional systems, are extended to the case where the parametric systems are not necessarily zero-dimensional. An algorithm is provided to compute GRDs and the associated RDU varieties of parametric systems simultaneously on the basis of the algorithm for generic zero-dimensional systems proposed in the authors' previous work. Then the solutions of any parametric system can be represented by the solutions of finitely many regular systems and the decomposition is stable at any parameter value in the complement of the associated RDU variety of the parameter space. The related definitions and the results presented in the authors' previous work are also generalized and a further discussion on RDU varieties is given from an experimental point of view. The new algorithm has been implemented on the basis of DISCOVERER with Maple 16 and experimented with a number of benchmarks from the literature. 展开更多
关键词 Generic regular decomposition parametric polynomial system regular-decomposition-unstable variety
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γMn-Cu合金在(γ+α)亚稳互溶区时效过程Spinodal分解的热力学判据 被引量:3
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作者 邓华铭 张骥华 陈树川 《功能材料与器件学报》 CAS CSCD 2001年第1期69-72,共4页
根据亚规则溶液模型,进行锰铜二元系的热力学计算表明,γ Mn-Cu合金在 (γ+α )亚稳互 溶区确实存在 Spinodal分解,在 400~ 600oC时效发生 Spinodal分解的是浓度范围为 60~ 90at% Mn 的合金。与硬度法相比,采用测量尼尔点来确定... 根据亚规则溶液模型,进行锰铜二元系的热力学计算表明,γ Mn-Cu合金在 (γ+α )亚稳互 溶区确实存在 Spinodal分解,在 400~ 600oC时效发生 Spinodal分解的是浓度范围为 60~ 90at% Mn 的合金。与硬度法相比,采用测量尼尔点来确定 Spinodal分解的区域较为可靠。 展开更多
关键词 γMn-Cu合金 SPINODAL分解 亚规则溶液 热力学 时效过程
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Description of Incomplete Financial Markets for Time Evolution of Risk Assets
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作者 Nicholas S. Gonchar 《Advances in Pure Mathematics》 2019年第6期567-610,共44页
In the paper, a class of discrete evolutions of risk assets having the memory is considered. For such evolutions the description of all martingale measures is presented. It is proved that every martingale measure is a... In the paper, a class of discrete evolutions of risk assets having the memory is considered. For such evolutions the description of all martingale measures is presented. It is proved that every martingale measure is an integral on the set of extreme points relative to some measure on it. For such a set of evolutions of risk assets, the contraction of the set of martingale measures on the filtration is described and the representation for it is found. The inequality for the integrals from a nonnegative random value relative to the contraction of the set of martingale measure on the filtration which is dominated by one is obtained. Using these inequalities a new proof of the optional decomposition theorem for super-martingales is presented. The description of all local regular super-martingales relative to the regular set of measures is presented. The applications of the results obtained to mathematical finance are presented. In the case, as evolution of a risk asset is given by the discrete geometric Brownian motion, the financial market is incomplete and a new formula for the fair price of super-hedge is founded. 展开更多
关键词 RANDOM Process regular Set of Measures Optional Doob decomposition Local regular Super-Martingale MARTINGALE Discrete GEOMETRIC BROWNIAN Motion
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