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VARIATIONAL ANALYSIS FOR THE MAXIMAL TIME FUNCTION IN NORMED SPACES
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作者 Ziyi ZHOU Yi JIANG 《Acta Mathematica Scientia》 SCIE CSCD 2024年第5期1696-1706,共11页
For a general normed vector space,a special optimal value function called a maximal time function is considered.This covers the farthest distance function as a special case,and has a close relationship with the smalle... For a general normed vector space,a special optimal value function called a maximal time function is considered.This covers the farthest distance function as a special case,and has a close relationship with the smallest enclosing ball problem.Some properties of the maximal time function are proven,including the convexity,the lower semicontinuity,and the exact characterizations of its subdifferential formulas. 展开更多
关键词 maximal time function SUBDIFFERENTIAL normal cone nonsmooth analysis
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MAXIMAL FUNCTION CHARACTERIZATIONS OF HARDY SPACES ASSOCIATED WITH BOTH NON-NEGATIVE SELF-ADJOINT OPERATORS SATISFYING GAUSSIAN ESTIMATES AND BALL QUASI-BANACH FUNCTION SPACES
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作者 林孝盛 杨大春 +1 位作者 杨四辈 袁文 《Acta Mathematica Scientia》 SCIE CSCD 2024年第2期484-514,共31页
Assume that L is a non-negative self-adjoint operator on L^(2)(ℝ^(n))with its heat kernels satisfying the so-called Gaussian upper bound estimate and that X is a ball quasi-Banach function space onℝ^(n) satisfying som... Assume that L is a non-negative self-adjoint operator on L^(2)(ℝ^(n))with its heat kernels satisfying the so-called Gaussian upper bound estimate and that X is a ball quasi-Banach function space onℝ^(n) satisfying some mild assumptions.Let HX,L(ℝ^(n))be the Hardy space associated with both X and L,which is defined by the Lusin area function related to the semigroup generated by L.In this article,the authors establish various maximal function characterizations of the Hardy space HX,L(ℝ^(n))and then apply these characterizations to obtain the solvability of the related Cauchy problem.These results have a wide range of generality and,in particular,the specific spaces X to which these results can be applied include the weighted space,the variable space,the mixed-norm space,the Orlicz space,the Orlicz-slice space,and the Morrey space.Moreover,the obtained maximal function characterizations of the mixed-norm Hardy space,the Orlicz-slice Hardy space,and the Morrey-Hardy space associated with L are completely new. 展开更多
关键词 Hardy space ball quasi-Banach function space Gaussian upper bound estimate non-negative self-adjoint operator maximal function
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Continuity of truncated Hardy-Littlewood maximal function
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作者 WANG Yidong WU Jia YAN Dunyan 《中国科学院大学学报(中英文)》 CAS CSCD 北大核心 2024年第6期721-727,共7页
This paper focuses on the continuity of the truncated Hardy-Littlewood maximal function.We first show that the truncated Hardy-Littlewood maximal function is lower semi-continuous.Then by investigating the behavior of... This paper focuses on the continuity of the truncated Hardy-Littlewood maximal function.We first show that the truncated Hardy-Littlewood maximal function is lower semi-continuous.Then by investigating the behavior of the truncated Hardy-Littlewood maximal function when the truncated parameterγchanges,we obtain an equivalent condition of the continuity of the truncated Hardy-Littlewood maximal function. 展开更多
关键词 Hardy-Littlewood maximal function TRUNCATION CONTINUITY truncated parameter
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Commutators of Fractional Maximal Functions on Orlicz Spaces over Non-Homogeneous Metric Spaces
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作者 Guanghui LU Xuemei LI 《Journal of Mathematical Research with Applications》 CSCD 2024年第6期782-794,共13页
Let(X,d,μ)be a non-homogeneous metric measure space satisfying the geometrically doubling condition and the upper doubling condition.In this setting,the authors prove that the commutator M_(b)^(α)formed by b∈RBMO(... Let(X,d,μ)be a non-homogeneous metric measure space satisfying the geometrically doubling condition and the upper doubling condition.In this setting,the authors prove that the commutator M_(b)^(α)formed by b∈RBMO(μ)and the fractional maximal function M^((α))is bounded from Lebesgue spaces L^(p)(μ)into spaces L^(q)(μ),where 1/q=1/p-αforα∈(0,1)and p∈(1,1/α).Furthermore,the boundedness of the M_(b)^(α)on Orlicz spaces L^Φ(μ)is established. 展开更多
关键词 Non-homogeneous metric measure space fractional maximal function COMMUTATOR space RBMO(μ) Orlicz space
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Upper Bounds for the L_p-norms of the Maximal Functions of Martingales
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作者 曾六川 《Chinese Quarterly Journal of Mathematics》 CSCD 2002年第1期77-84,共8页
Let 2≤p【∞ and let (f n) be a martingale. Using exponential bounds of the probabilities of the type P(|f n|】λ‖T(f n)‖ ∞) for some quasi-linear operators acting on martingales, we estimate upper bounds for t... Let 2≤p【∞ and let (f n) be a martingale. Using exponential bounds of the probabilities of the type P(|f n|】λ‖T(f n)‖ ∞) for some quasi-linear operators acting on martingales, we estimate upper bounds for the L p-norms of the maximal functions of martinglaes. Our result is the extension and improvements of the results obtained previously by HITCZENKO and ZENG . 展开更多
关键词 MARTINGALE stopping time maximal function L p-norm
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Maximal operators of pseudo-differential operators with rough symbols
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作者 Ramla Benhamoud ZHU Xiang-rong 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2024年第1期174-180,共7页
Consider a pseudo-differential operator T_(a)f(x)=∫_(R^(n))e^(ix,ζ)a(x,ζ)f(ζ)dζwhere the symbol a is in the rough Hormander class L^(∞)S_(ρ)^(m)with m∈R andρ∈[0,1].In this note,when 1≤p≤2,if n(ρ-1)/p and ... Consider a pseudo-differential operator T_(a)f(x)=∫_(R^(n))e^(ix,ζ)a(x,ζ)f(ζ)dζwhere the symbol a is in the rough Hormander class L^(∞)S_(ρ)^(m)with m∈R andρ∈[0,1].In this note,when 1≤p≤2,if n(ρ-1)/p and a∈L^(∞)S_(ρ)^(m),then for any f∈S(R^(n))and x∈R^(n),we prove that M(T_(a)f)(x)≤C(M(|f|^(p))(x))^(1/p) where M is the Hardy-Littlewood maximal operator.Our theorem improves the known results and the bound on m is sharp,in the sense that n(ρ-1)/p can not be replaced by a larger constant. 展开更多
关键词 pseudo-differential operator rough Hormander class h-l maximal operator
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A MAXIMAL FUNCTION CHARACTERIZATION 0F HARDY SPACES ON SPACES OF HOMOGENEOUS TYPE 被引量:6
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作者 Li Wenming Zhongshan University, China 《Analysis in Theory and Applications》 1998年第2期12-27,共16页
A new maximal function is introduced in the dual spaces of test function spaces on spaces of homogeneous type. Using this maximal function, we get new characterization of atomic H^p spaces.
关键词 A maximal function CHARACTERIZATION 0F HARDY SPACES ON SPACES OF HOMOGENEOUS TYPE APPI 尸气
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W ^(1,p)(R^n)-BOUNDEDNESS FOR MAXIMAL FUNCTIONS
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作者 Li Cheng Department of Mathematics Lishui University Lishui, 323000P. R. China 《Analysis in Theory and Applications》 2009年第1期86-91,共6页
In this paper, we get W 1,p(Rn)-boundedness for tangential maximal func- tion and nontangential maximal function , which improves J.Kinnunen, P.Lindqvist and Tananka’s results.
关键词 tangential maximal function nontangential maximal function W 1 p(Rn)- boundedness
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SHARP MAXIMAL FUNCTION ESTIMATE AND WEIGHTED INEQUALITIES FOR MAXIMAL MULTILINEAR SINGULAR INTEGRALS
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作者 Wenming Li Limei Xue Xuefang Yan 《Analysis in Theory and Applications》 2011年第2期158-166,共9页
For maximal multilinear Calderon-Zygmund singular integral operators, the sharp maximal function estimate and some weighted norm inequalities are obtained.
关键词 multilinear Calderon-Zygmund operator sharp maximal function weightednorm inequality
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Maximally Holomorphic Functions of a Bounded Linear Operator
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作者 刘水强 《邵阳学院学报(社会科学版)》 1998年第2X期11-15,共5页
The maximally holomorphic functions of a bounded linear operator is introduced and applied to representthe spectrum and characterize the single--valued extension property. The well known results of quasi--nilpo-tent e... The maximally holomorphic functions of a bounded linear operator is introduced and applied to representthe spectrum and characterize the single--valued extension property. The well known results of quasi--nilpo-tent equivalent operators follow easily from the relation of their maximally holomorphie functions. 展开更多
关键词 maximalLY HOLOMORPHIC functions the single--valued extension property the SPECTRUM the local SPECTRUM quasi--nilpotent equivalent operators.
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BOUNDEDNESS OF FRACTIONAL MAXIMAL OPERATOR AND THEIR HIGHER ORDER COMMUTATORS IN GENERALIZED MORREY SPACES ON CARNOT GROUPS 被引量:5
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作者 Vagif GULIYEV Ali AKBULUT Yagub MAMMADOV 《Acta Mathematica Scientia》 SCIE CSCD 2013年第5期1329-1346,共18页
In the article we consider the fractional maximal operator Mα, 0 ≤α 〈 Q on any Carnot group G (i.e., nilpotent stratified Lie group) in the generalized Morrey spaces Mp,φ(G), where Q is the homogeneous dimens... In the article we consider the fractional maximal operator Mα, 0 ≤α 〈 Q on any Carnot group G (i.e., nilpotent stratified Lie group) in the generalized Morrey spaces Mp,φ(G), where Q is the homogeneous dimension of G. We find the conditions on the pair (φ1, φ2) which ensures the boundedness of the operator Ms from one generalized Morrey space Mp,φ1 (G) to another Mq,φ2 (G), 1. 〈 p ≤q 〈 ∞. 1/p - 1/q = α/Q, and from the space M1,φ1 (G) to the weak space Wq,φ2 (G), 1 〈 q 〈 ∞, 1 - 1/q = α/Q. Also find conditions on the φ which ensure the Adams type boundedness of the Ms from M α (G) from Mp,φ^1/p(G)to Mq,φ^1/q(G) for 1 〈p〈q〈∞ and fromM1,φ(G) toWMq,φ^1/q(G)for 1〈q〈∞. In the case b ∈ BMO(G) and 1 〈 p 〈 q 〈 ∞, find the sufficient conditions on the pair (φ1, φ2) which ensures the boundedness of the kth-order commutator operator Mb,α,k from Mp,φ1 (G) to Mq,φ2(G) with 1/p - 1/q = α/Q. Also find the sufficient conditions on the φ which ensures the boundedness of the operator Mb,α,k from Mp,φ^1/p(G) tom Mp,φ^1/p (G) for 1 〈p〈q〈∞. In all the cases the conditions for the boundedness of Mα are given it terms of supremaltype inequalities on (φ1, φ2) and φ , which do not assume any assumption on monotonicity of (φ1, φ2) and φ in r. As applications we consider the SchrSdinger operator -△G + V on G, where the nonnegative potential V belongs to the reverse Holder class B∞(G). The MB,φ1 - Mq,φ2 estimates for the operators V^γ(-△G + V)^-β and V^γ△↓G(-△G + V)^-β are obtained. 展开更多
关键词 Carnot group fractional maximal function generalized Morrey space Schrodinger operator BMO space
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A FOUR-WEIGHT WEAK TYPE MAXIMAL INEQUALITY FOR MARTINGALES 被引量:1
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作者 Yanbo REN 《Acta Mathematica Scientia》 SCIE CSCD 2019年第2期413-419,共7页
In this article, some necessary and sufficient conditions are shown in order that weighted inequality of the form ■holds a.e. for uniformly integrable martingales f =(f_n)n≥0 with some constant C > 0,where Φ_1,... In this article, some necessary and sufficient conditions are shown in order that weighted inequality of the form ■holds a.e. for uniformly integrable martingales f =(f_n)n≥0 with some constant C > 0,where Φ_1,Φ_2 are Young functions, w_i(i = 1,2,3, 4) are weights, f~* =sup n≥0 |f_n| and f_∞=lim n→∞ f_n a.e. As an application, two-weight weak type maximal inequalities of martingales are considered, and particularly a new equivalence condition is presented. 展开更多
关键词 WEIGHT WEAK TYPE inequality MARTINGALE maximal operator Young function
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Stability and stabilization of discrete T-S fuzzy time-delay system based on maximal overlapped-rules group 被引量:2
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作者 Songtao Zhang Xiaowei Zhao Jiantong Zhang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第1期201-210,共10页
The problems of stability and stabilization for the discrete Takagi-Sugeno(T-S) fuzzy time-delay system are investigated.By constructing a discrete piecewise Lyapunov-Krasovskii function(PLKF) in each maximal over... The problems of stability and stabilization for the discrete Takagi-Sugeno(T-S) fuzzy time-delay system are investigated.By constructing a discrete piecewise Lyapunov-Krasovskii function(PLKF) in each maximal overlapped-rules group(MORG),a new sufficient stability condition for the open-loop discrete T-S fuzzy time-delay system is proposed and proved.Then the systematic design of the fuzzy controller is investigated via the parallel distributed compensation control scheme,and a new stabilization condition for the closed-loop discrete T-S fuzzy time-delay system is proposed.The above two sufficient conditions only require finding common matrices in each MORG.Compared with the common Lyapunov-Krasovskii function(CLKF) approach and the fuzzy Lyapunov-Krasovskii function(FLKF) approach,these proposed sufficient conditions can not only overcome the defect of finding common matrices in the whole feasible region but also largely reduce the number of linear matrix inequalities to be solved.Finally,simulation examples show that the proposed PLKF approach is effective. 展开更多
关键词 stability analysis maximal overlapped-rules group(MORG) Takagi-Sugeno(T-S)fuzzy model discrete time-delay system piecewise Lyapunov-Krasovskii function(PLKF).
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WEAK BOUNDS FOR ROUGH SQUARE AND MAXIMAL OPERATORS
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作者 Ying Yiming Yao KuiDept.ofMath.,ZhejiangUniv.(XiXiCampus),Hangzhou310028.InstituteofSciences,PLAUniv.ofScienceandTechnology,Nanjing211101. 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2001年第2期161-170,共10页
With Ω ∈ L (log + L)(S n-1 ) and suitable h ∈ L γ (R 1)(1<γ≤2),the weak type (1,1) of the square function g(f)(x) =k|ψ k*f| 2 12(x) and the maximal operator M ψ(f)(x) = sup ... With Ω ∈ L (log + L)(S n-1 ) and suitable h ∈ L γ (R 1)(1<γ≤2),the weak type (1,1) of the square function g(f)(x) =k|ψ k*f| 2 12(x) and the maximal operator M ψ(f)(x) = sup k|ψ k|*|f|(x) where ψ(x)=|x| -n Ω(x)h(|x|),ψ k(x)=ψ 2 k (x), are studied in this paper.As a corollary,the weak bounds of M Ω(f) proved by Christ in 1988 are given and the previous weak type results for M ψ(f)(x) are improved.In addition,the weighted weak type (1,1) estimates of the Littlewood Paley function g ψ(f) with power weights is also proved. 展开更多
关键词 Square functions maximal operators rough kernel power weight.
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Boundedness of Fractional Maximal Operators on Some of Homogeneous Groups
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作者 王杰 陈丙康 张建林 《Journal of Beijing Institute of Technology》 EI CAS 2004年第4期449-453,共5页
Let M α be the fractional maximal operators (0<α≤1) and (u,v) a pair of weight functions, u∈D ∞, σ=v~~~~^(-1/(p-1))∈A ∞. The boundedness of M α on some homogenous groups (G, ‖·‖, dx) and the cov... Let M α be the fractional maximal operators (0<α≤1) and (u,v) a pair of weight functions, u∈D ∞, σ=v~~~~^(-1/(p-1))∈A ∞. The boundedness of M α on some homogenous groups (G, ‖·‖, dx) and the covering Lemma of Calderon-Zygmund type are studied. Not only an adequate covering Lemma of Calderon-Zygmund type is shown, but also the boundedness of fractional maximal operators M α(0<α≤1) on some of homogeneous groups with respect to a given pair of weight functions (u,v) as above is proved. Moreover, a sufficient and necessary condition for M α∈B(u^qdx, v~~pdx), 0<α<1, 1<p<1α, and 1q=1p-α is also given. Finally, an application of the results is also obtained. 展开更多
关键词 BOUNDEDNESS fractional maximal operator homogeneous groups weight functions
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MAXIMAL CHARACTERIZATIONS OF HERZ TYPE HARDY SPACES ON HOMOGENEOUS GROUPS
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作者 Yinsheng Jiang Lin Tang 《Analysis in Theory and Applications》 2005年第4期301-310,共10页
In this paper, the authors establish some characterizations of Herz-type Hardy spaces HKq^α,P(G) and HKq^α,P(G), where 1 〈 q 〈 ∞, Q(1 - 1/q) ≤ α 〈 ∞, 0 〈 p 〈 ∞ and G denotes a gfaded homogeneous Lie ... In this paper, the authors establish some characterizations of Herz-type Hardy spaces HKq^α,P(G) and HKq^α,P(G), where 1 〈 q 〈 ∞, Q(1 - 1/q) ≤ α 〈 ∞, 0 〈 p 〈 ∞ and G denotes a gfaded homogeneous Lie group. 展开更多
关键词 homogeneous group Hardy space Herz space maximal functions
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Composition of Maximal Operators on Space of Homogeneous Type
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作者 YUAN Xin-feng ZHANG Hao 《Chinese Quarterly Journal of Mathematics》 CSCD 2010年第2期249-256,共8页
Let Ф be a Young function and MФ be the maximal operator associated with in the space of homogeneous type. In this paper, the composition of the maximal operators of type MФ is considered, and the result establishe... Let Ф be a Young function and MФ be the maximal operator associated with in the space of homogeneous type. In this paper, the composition of the maximal operators of type MФ is considered, and the result established by Carrozza and Passarelli Di Napoli is generalized to the space of homogeneous type. 展开更多
关键词 maximal operator space of homogeneous type Young function Calderen-Zygmund decomposition
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Equivalence between Linear Tangle and Maximal Single Ideal
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作者 Takaaki Fujita Koichi Yamazaki 《Open Journal of Discrete Mathematics》 2019年第1期7-10,共4页
The concept of linear tangle was introduced as an obstruction to mixed searching number. The concept of (maximal) single ideal has been introduced as an obstruction to linear-width. Moreover, it was already known that... The concept of linear tangle was introduced as an obstruction to mixed searching number. The concept of (maximal) single ideal has been introduced as an obstruction to linear-width. Moreover, it was already known that mixed search number is equivalent to linear-width. Hence, by combining those results, we obtain a proof of the equivalence between linear tangle and maximal single ideal. This short report gives an alternative proof of the equivalence. 展开更多
关键词 LINEAR TANGLE maximal SINGLE IDEAL Submodular function
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Boundedness of the Maximal Operator on Lip_α(R^n) (0<α<1)
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作者 岳优兰 王月山 《Chinese Quarterly Journal of Mathematics》 CSCD 1999年第2期108-110, ,共3页
It provides the boundary proof of the maximal operator on Lipschitz space. i.e.,if f ∈Lip α(R n) (0<α<1) and inf x∈R nM(f)(x) <∞, then almost every x∈R n has M(f)(x) <∞ and exists a constant C indep... It provides the boundary proof of the maximal operator on Lipschitz space. i.e.,if f ∈Lip α(R n) (0<α<1) and inf x∈R nM(f)(x) <∞, then almost every x∈R n has M(f)(x) <∞ and exists a constant C independent of f and x ,such that ‖M(f)‖ ∧ α ≤C‖f‖ ∧ α . 展开更多
关键词 the maximal operator function space of Lipschitz BOUNDEDNESS
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扩散模型期望最大化的离线强化学习方法
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作者 刘全 颜洁 乌兰 《软件学报》 北大核心 2025年第10期4695-4709,共15页
在连续且密集奖励的任务中,离线强化学习取得了显著的效果.然而由于其训练过程不与环境交互,泛化能力降低,在离散且稀疏奖赏的环境下性能难以得到保证.扩散模型通过加噪结合样本数据邻域的信息,生成贴近样本数据分布的动作,强化智能体... 在连续且密集奖励的任务中,离线强化学习取得了显著的效果.然而由于其训练过程不与环境交互,泛化能力降低,在离散且稀疏奖赏的环境下性能难以得到保证.扩散模型通过加噪结合样本数据邻域的信息,生成贴近样本数据分布的动作,强化智能体的学习和泛化能力.针对以上问题,提出一种扩散模型期望最大化的离线强化学习方法(offline reinforcement learning with diffusion models and expectation maximization,DMEM).该方法通过极大似然对数期望最大化更新目标函数,使策略具有更强的泛化性.将扩散模型引入策略网络中,利用扩散的特征,增强策略学习数据样本的能力.同时从高维空间的角度看期望回归更新价值函数,引入一个惩戒项使价值函数评估更准确.将DMEM应用于一系列离散且稀疏奖励的任务中,实验表明,与其他经典的离线强化学习方法相比,DMEM性能上具有较大的优势. 展开更多
关键词 离线强化学习 扩散模型 优势函数加权 期望回归 期望最大化
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