期刊文献+
共找到19,867篇文章
< 1 2 250 >
每页显示 20 50 100
MINIMIZERS OF L^(2)-SUBCRITICAL VARIATIONAL PROBLEMS WITH SPATIALLY DECAYING NONLINEARITIES IN BOUNDED DOMAINS
1
作者 陈彬 高永帅 +1 位作者 郭玉劲 吴越 《Acta Mathematica Scientia》 SCIE CSCD 2024年第3期984-996,共13页
This paper is concerned with the minimizers of L^(2)-subcritical constraint variar tional problems with spatially decaying nonlinearities in a bounded domain Ω of R~N(N≥1).We prove that the problem admits minimizers... This paper is concerned with the minimizers of L^(2)-subcritical constraint variar tional problems with spatially decaying nonlinearities in a bounded domain Ω of R~N(N≥1).We prove that the problem admits minimizers for any M> 0.Moreover,the limiting behavior of minimizers as M→∞ is also analyzed rigorously. 展开更多
关键词 decaying nonlinearity L~2-subcritical MINIMIZERS bounded domains mass concentration
下载PDF
L^p Boundedness of Commutators of Calderón-Zygmund Singular Integral Operators 被引量:8
2
作者 邓东皋 颜立新 《数学进展》 CSCD 北大核心 1998年第3期259-269,共11页
本文证明了当b∈BMO时,具有弱核的CalderónZygmund奇异积分算子的交换子[b,T]f=bT(f)-T(bf)是Lp(1<p<∞)有界的.一个等价的命题是双线性算子gT(f)-fT(g)∈H1,只... 本文证明了当b∈BMO时,具有弱核的CalderónZygmund奇异积分算子的交换子[b,T]f=bT(f)-T(bf)是Lp(1<p<∞)有界的.一个等价的命题是双线性算子gT(f)-fT(g)∈H1,只要f∈Lp,g∈Lq,1<p<∞,1p+1q=1. 展开更多
关键词 交换子 HARDY空间 奇异积分算子 L^P有界
下载PDF
The Boundedness of Some Singular Integral Operators 被引量:1
3
作者 杨大春 《Chinese Quarterly Journal of Mathematics》 CSCD 1990年第1期187-196,共10页
In this paper we show that if K(x)=Ω(x)l|\x|~n is a Calderon-Zygmu- nd kernel,where Ω∈L^q(S^(n-1)) for some 1<q≤∞,and b(x) is a radial function such that |b(r)|~p·dr≤cR for all R>0 and some 1<p_0&... In this paper we show that if K(x)=Ω(x)l|\x|~n is a Calderon-Zygmu- nd kernel,where Ω∈L^q(S^(n-1)) for some 1<q≤∞,and b(x) is a radial function such that |b(r)|~p·dr≤cR for all R>0 and some 1<p_0<∞,then Tf=P.V.(bK)*f is bounded on L^p() for 1<p≤∞ and n≥2.Moreover, we show that T is bounded from BMO to BMO iff b(x) is satisfied the condition star (*). 展开更多
关键词 奇异积分算子 有界 径向函数 ∞-block函数 BMO函数 Fourier变换 HOELDER不等式 有界线性算子 卷积算子
下载PDF
Completeness of bounded model checking temporal logic of knowledge
4
作者 刘志锋 葛云 +1 位作者 章东 周从华 《Journal of Southeast University(English Edition)》 EI CAS 2010年第3期399-405,共7页
In order to find the completeness threshold which offers a practical method of making bounded model checking complete, the over-approximation for the complete threshold is presented. First, a linear logic of knowledge... In order to find the completeness threshold which offers a practical method of making bounded model checking complete, the over-approximation for the complete threshold is presented. First, a linear logic of knowledge is introduced into the past tense operator, and then a new temporal epistemic logic LTLKP is obtained, so that LTLKP can naturally and precisely describe the system's reliability. Secondly, a set of prior algorithms are designed to calculate the maximal reachable depth and the length of the longest of loop free paths in the structure based on the graph structure theory. Finally, some theorems are proposed to show how to approximate the complete threshold with the diameter and recurrence diameter. The proposed work resolves the completeness threshold problem so that the completeness of bounded model checking can be guaranteed. 展开更多
关键词 bounded model checking temporal logics of knowledge multi-agent system
下载PDF
THE BASIC THEORY OF SOLUTIONS OF FUNCTIONAL DIFFERENTIAL EQUATIONS WITH BOUNDED DELAY IN THE SPACE OF INTEGRABLE FUNCTIONS
5
作者 刘永清 李远清 《华南理工大学学报(自然科学版)》 EI CAS CSCD 北大核心 1997年第7期67-73,共7页
在可积函数空间中讨论有界滞量泛函微分方程,建立其解的基本理论,包括解的存在性,唯一性及延展性。
关键词 有界滞量的泛函微分方程 存在性 唯一性 延展性 可积函数空间
下载PDF
Boundedness of Solutions of A Class of Certain Integro-Differential Equations 被引量:1
6
作者 孟繁伟 《Chinese Quarterly Journal of Mathematics》 CSCD 1989年第2期102+94-101,共9页
本文研究了积分-微分方程解的有界性质。给出了方程(A)所有解有界的判別准则,同时也研究了方程(A)解的渐近性质。给出了方程(A)所有解当t→∞时趋向于有穷极限的充分条件。
关键词 解的有界 积分-微分方程 渐近性质 有穷 proof boundedNESS INEQUALITY 数学季刊 satisfied quasi
下载PDF
SOME PROPERTIES OF BOUNDED SETS IN INDUCTIVE LIMITS
7
作者 丘京辉 《苏州大学学报(自然科学版)》 CAS 1991年第2期109-114,共6页
Let (E,ξ)=indlim (En,ξn) be an inductive limit of a sequence of locally convex spaces,For brevity,denote by (DS) each set Bbounded in (E,ξ) is contained in some En; and (DST) each set B bounded in (E,ξ) is co... Let (E,ξ)=indlim (En,ξn) be an inductive limit of a sequence of locally convex spaces,For brevity,denote by (DS) each set Bbounded in (E,ξ) is contained in some En; and (DST) each set B bounded in (E,ξ) is contained and bounded in some (En,ξn). Theovem 1.(DS) holds provided that (i) for each n∈N,there is a neighborhood Un of o in (En,ξn) and m(n)∈ such that -↑Un^E包含于Em(n),and (ii) for any neighborhood V n of o in (En,ξn),∞↑Un=1 Vn absorbs every bounded set in (E,ξ). theorem 2 Let all (En,ξn) be metrizable and (DS) hold,then for each bounded set B IN (E,ξ)and each n ∈N thcrc is a neighborhood U k of o in (Ek,ξk), 1≤k≤n ,and m(n)∈N such that ——↑(B+U1+U2+…+Un)^E包含于 Em(n). theorem 3. Let all (En,ξn) be Frechet spaces.Then (DST) holds if and only if (i) for each n ∈N,there is u neighborhood U n of in (En,ξn) and m(n)∈N such that 0↑Un^E包含于Em(n),and (ii) for each each closed ,absosed,absolutely conuex,bounded set B in (E,ξ),∞↑Un=1((εnB)∩Un)absorbs B,where U n is any neighborhood of o in (En,ξn) and εn is any positive number for every n ∈N。 展开更多
关键词 有界 归纳极限 凸空间 线性拓扑空间
下载PDF
指数有界双连续n阶α次积分C半群的扰动 被引量:1
8
作者 赵华新 贺凯丽 刘娟娟 《沈阳大学学报(自然科学版)》 CAS 2024年第1期86-90,共5页
利用经典算子半群理论中的研究方法,在指数有界双连续α次积分C半群的基础上,讨论了指数有界双连续n阶α次积分C半群的扰动定理。设A为次生成元的指数有界双连续n阶α次积分C半群{T(t)}_(t≥0),B为界线性算子,A、B、C可交换,则在一定条... 利用经典算子半群理论中的研究方法,在指数有界双连续α次积分C半群的基础上,讨论了指数有界双连续n阶α次积分C半群的扰动定理。设A为次生成元的指数有界双连续n阶α次积分C半群{T(t)}_(t≥0),B为界线性算子,A、B、C可交换,则在一定条件下,C^(-1)(A+B)C_(B)生成双连续n阶α次积分C半群{T_(B)(t)}_(t≥0),并给出T_(B)(t)的表达式,从而推广了n阶α次积分C半群相关的扰动定理。 展开更多
关键词 双连续 n阶α次积分C半群 扰动 指数有界 生成元
下载PDF
非线性系统无需初始条件预设性能有界H_(∞)容错控制
9
作者 李小华 程鸿展 刘辉 《控制理论与应用》 EI CAS CSCD 北大核心 2024年第2期273-282,共10页
针对一类具有外部扰动和传感器故障的非线性系统,本文研究了其自适应预设性能有界H_(∞) 容错控制问题.本文提出一种新的预设性能控制设计方法,使得预设性能函数的选择与系统被约束变量的初始状态完全无关,用一种全新的方式解决了传统... 针对一类具有外部扰动和传感器故障的非线性系统,本文研究了其自适应预设性能有界H_(∞) 容错控制问题.本文提出一种新的预设性能控制设计方法,使得预设性能函数的选择与系统被约束变量的初始状态完全无关,用一种全新的方式解决了传统预设性能方法的控制效果依赖被约束变量初始条件的问题.基于该设计方法和有界H_(∞) 控制方法,在未知系统初始条件的情况下获得了系统的自适应预设性能有界H_(∞) 控制器.本文所设计的控制器能够保证系统中的所有信号都是有界稳定的,系统的输出变量能够被预设性能函数约束,并且对于外部干扰具有很好的抑制作用.最后,仿真结果验证了该控制器的可行性及有效性. 展开更多
关键词 非线性系统 传感器故障 预设性能控制 无需初始条件 有界H_(∞)控制 容错控制
下载PDF
指数有界n阶α次积分C群的紧性
10
作者 赵华新 刘娟娟 贺凯丽 《沈阳大学学报(自然科学版)》 CAS 2024年第3期267-272,共6页
利用指数有界n阶α次积分C群及其次生成元的定义,并借助经典算子理论的研究方法,给出了指数有界n阶α次积分C群紧的定义,从而推导出指数有界n阶α次积分C群的紧性的一些性质。
关键词 指数有界 n阶α次积分C群 次生成元 紧性 拓扑连续
下载PDF
指数有界双连续n阶α次积分C半群与高阶抽象Cauchy问题研究
11
作者 葛国菊 《佳木斯大学学报(自然科学版)》 CAS 2024年第4期173-176,92,共5页
算子半群理论在求解Cauchy问题等领域具有很大的应用价值,并且其在泛函分析理论等各方面的研究中同样有着重要意义。此次研究在Banach空间上,基于泛函分析、算子半群理论对柯西问题进行探讨。并基于n阶α次积分C半群的生成定理,对指数... 算子半群理论在求解Cauchy问题等领域具有很大的应用价值,并且其在泛函分析理论等各方面的研究中同样有着重要意义。此次研究在Banach空间上,基于泛函分析、算子半群理论对柯西问题进行探讨。并基于n阶α次积分C半群的生成定理,对指数有界双连续n阶α次积分C半群的生成定理与其Laplace逆变换表达式进行推算。由结果可知,L∞范数误差在分数阶n为1.47时达到最低值,为0.04,这表明其与实际值极为接近。在T=0.2,0.5两种时刻下,中精确解和正则解的变化趋势基本一致,并且二者的误差在x∈0.1,0.9区间内接近于0。研究有效验证了指数有界双连续n阶α次积分C半群解决高阶抽象Cauchy问题具有适用性与可靠性。 展开更多
关键词 高阶抽象Cauchy问题 适定性 指数有界 双连续 n阶α次积分C半群
下载PDF
GLOBALLY BOUNDED IN-TIME SOLUTIONS TO A PARABOLIC-ELLIPTIC SYSTEM MODELLING CHEMOTAXIS 被引量:3
12
作者 钟新华 江松 《Acta Mathematica Scientia》 SCIE CSCD 2007年第2期421-429,共9页
In this article, the globally bounded in-time pointwise estimate of solutions to the simplified Keller-Segel system modelling chemotaxis are derived. Moreover, a local existence theorem is obtained.
关键词 Keller-Segel system CHEMOTAXIS globally bounded
下载PDF
A NEW PERTURBATION THEOREM FOR MOORE-PENROSE METRIC GENERALIZED INVERSE OF BOUNDED LINEAR OPERATORS IN BANACH SPACES 被引量:3
13
作者 王紫 王玉文 《Acta Mathematica Scientia》 SCIE CSCD 2017年第6期1619-1631,共13页
In this paper, we investigate a new perturbation theorem for the Moore-Penrose metric generalized inverses of a bounded linear operator in Banach space. The main tool in this paper is "the generalized Neumann lemma"... In this paper, we investigate a new perturbation theorem for the Moore-Penrose metric generalized inverses of a bounded linear operator in Banach space. The main tool in this paper is "the generalized Neumann lemma" which is quite different from the method in [12] where "the generalized Banach lemma" was used. By the method of the perturba- tion analysis of bounded linear operators, we obtain an explicit perturbation theorem and three inequalities about error estimates for the Moore-Penrose metric generalized inverse of bounded linear operator under the generalized Neumann lemma and the concept of stable perturbations in Banach spaces. 展开更多
关键词 Banach space bounded linear operator metric projection generalized inverse perturbation analysis Moore-Penrose quasi-additive
下载PDF
THE EQUIVALENT CHARACTERIZATION OF F(p,q,s)SPACE ON BOUNDED SYMMETRIC DOMAINS OF Cn 被引量:4
14
作者 黎深莲 张学军 徐思 《Acta Mathematica Scientia》 SCIE CSCD 2017年第6期1791-1802,共12页
LetΩ be a bounded symmetric domain in Cn. The purpose of this article is to define and characterize the general function space F(p, q, s) on Ω. Characterizing functions in the F(p, q, s) space is a work of consi... LetΩ be a bounded symmetric domain in Cn. The purpose of this article is to define and characterize the general function space F(p, q, s) on Ω. Characterizing functions in the F(p, q, s) space is a work of considerable interest nowadays. In this article, the authors give several equivalent descriptions of the functions in the F(p, q, s) space on Ω in terms of fractional differential operators. At the same time, the authors give the relationship between F(p, q, s) space and Bloch type space on Ω too. 展开更多
关键词 F(p q s) space equivalent description bounded symmetric domain
下载PDF
Wave packet solutions in a bounded equatorial ocean and its interannual and decadal variabilities 被引量:2
15
作者 Dongling Zhang Juan Zhu +1 位作者 Xu Lu Ming Zhang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2019年第3期45-59,共15页
Linearized shallow water perturbation equations with approximation in an equatorial β plane are used to obtain the analytical solution of wave packet anomalies in the upper bounded equatorial ocean. The main results ... Linearized shallow water perturbation equations with approximation in an equatorial β plane are used to obtain the analytical solution of wave packet anomalies in the upper bounded equatorial ocean. The main results are as follows. The wave packet is a superposition of eastward travelling Kelvin waves and westward travelling Rossby waves with the slowest speed, and satisfies the boundary conditions of eastern and western coasts, respectively.The decay coefficient of this solution to the north and south sides of the equator is inversely proportional only to the phase velocity of Kelvin waves in the upper water. The oscillation frequency of the wave packet, which is also the natural frequency of the ocean, is proportional to its mode number and the phase velocity of Kelvin waves and is inversely proportional to the length of the equatorial ocean in the east-west direction. The flow anomalies of the wave packet of Mode 1 most of the time appear as zonal flows with the same direction. They reach the maximum at the center of the equatorial ocean and decay rapidly away from the equator, manifested as equatorially trapped waves. The flow anomalies of the wave packet of Mode 2 appear as the zonal flows with the same direction most of the time in half of the ocean, and are always 0 at the center of the entire ocean which indicates stagnation, while decaying away from the equator with the same speed as that of Mode 1. The spatial structure and oscillation period of the wave packet solution of Mode 1 and Mode 2 are consistent with the changing periods of the surface spatial field and time coefficient of the first and second modes of complex empirical orthogonal function(EOF)analysis of flow anomalies in the actual equatorial ocean. This indicates that the solution does exist in the real ocean, and that El Ni?o-Southern Oscillation(ENSO) and Indian Ocean dipole(IOD) are both related to Mode 2.After considering the Indonesian throughflow, we can obtain the length of bounded equatorial ocean by taking the sum of that of the tropical Indian Ocean and the tropical Pacific Ocean, thus this wave packet can also explain the decadal variability(about 20 a) of the equatorial Pacific and Indian Oceans. 展开更多
关键词 bounded EQUATORIAL OCEAN WAVE packet SOLUTIONS DECADAL variability Kelvin WAVE Rossby WAVE
下载PDF
Energy-Optimal and Delay-Bounded Computation Offloading in Mobile Edge Computing with Heterogeneous Clouds 被引量:24
16
作者 Tianchu Zhao Sheng Zhou +3 位作者 Linqi Song Zhiyuan Jiang Xueying Guo Zhisheng Niu 《China Communications》 SCIE CSCD 2020年第5期191-210,共20页
By Mobile Edge Computing(MEC), computation-intensive tasks are offloaded from mobile devices to cloud servers, and thus the energy consumption of mobile devices can be notably reduced. In this paper, we study task off... By Mobile Edge Computing(MEC), computation-intensive tasks are offloaded from mobile devices to cloud servers, and thus the energy consumption of mobile devices can be notably reduced. In this paper, we study task offloading in multi-user MEC systems with heterogeneous clouds, including edge clouds and remote clouds. Tasks are forwarded from mobile devices to edge clouds via wireless channels, and they can be further forwarded to remote clouds via the Internet. Our objective is to minimize the total energy consumption of multiple mobile devices, subject to bounded-delay requirements of tasks. Based on dynamic programming, we propose an algorithm that minimizes the energy consumption, by jointly allocating bandwidth and computational resources to mobile devices. The algorithm is of pseudo-polynomial complexity. To further reduce the complexity, we propose an approximation algorithm with energy discretization, and its total energy consumption is proved to be within a bounded gap from the optimum. Simulation results show that, nearly 82.7% energy of mobile devices can be saved by task offloading compared with mobile device execution. 展开更多
关键词 mobile edge computing heterogeneous clouds energy saving delay bounds dynamic programming
下载PDF
Robust controller design for compound control missile with fixed bounded convergence time 被引量:4
17
作者 YUN Yuhang TANG Shengjing +1 位作者 GUO Jie SHANG Wei 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2018年第1期116-133,共18页
A robust controller for bank to turn(BTT) missiles with aerodynamic fins and reaction jet control system(RCS) is developed based on nonlinear control dynamic models comprising couplings and aerodynamic uncertainties. ... A robust controller for bank to turn(BTT) missiles with aerodynamic fins and reaction jet control system(RCS) is developed based on nonlinear control dynamic models comprising couplings and aerodynamic uncertainties. The fixed time convergence theory is incorporated with the sliding mode control technique to ensure that the system tracks the desired command within uniform bounded time under different initial conditions. Unlike previous terminal sliding mode approaches, the bound of settling time is independent of the initial state, which means performance metrics like convergence rate can be predicted beforehand. To reduce the burden of control design in terms of robustness, extended state observer(ESO) is introduced for uncertainty estimation with the output substituted into the controller as feedforward compensation. Cascade control structure is employed with the proposed control law and therein the compound control signal is obtained.Afterwards, control inputs for two kinds of actuators are allocated on the basis of their inherent characteristics. Finally, a number of simulations are carried out and demonstrate the effectiveness of the designed controller. 展开更多
关键词 reaction jet control compound control fixed bounded convergence time sliding mode control extended state observer(ESO)
下载PDF
INCOMPRESSIBLE LIMIT OF THE NON-ISENTROPIC MAGNETOHYDRODYNAMIC EQUATIONS IN BOUNDED DOMAINS 被引量:2
18
作者 王术 徐自立 《Acta Mathematica Scientia》 SCIE CSCD 2015年第3期719-745,共27页
The incompressible limit of the non-isentropic magnetohydrodynamic equations with zero thermal coefficient, in a two dimensional bounded domain with the Dirichlet condi- tion for velocity and perfectly conducting boun... The incompressible limit of the non-isentropic magnetohydrodynamic equations with zero thermal coefficient, in a two dimensional bounded domain with the Dirichlet condi- tion for velocity and perfectly conducting boundary condition for magnetic field, is rigorously justified. 展开更多
关键词 Low Mach number limit non-isentropic magnetohydrodynamic equations bounded domain
下载PDF
Bounded Real Lemma for Generalized Linear System with Finite Discrete Jumps 被引量:1
19
作者 何黎明 杨晓军 翁正新 《Journal of Shanghai Jiaotong university(Science)》 EI 2006年第4期440-444,共5页
The strict bounded real lemma for linear system with finite discrete jumps was considered. Especially, the case where D matrices in the system are not assumed to be zero was dealt. Several versions of the bounded real... The strict bounded real lemma for linear system with finite discrete jumps was considered. Especially, the case where D matrices in the system are not assumed to be zero was dealt. Several versions of the bounded real lemma are presented in terms of solution to Riccati differential equations or inequalities with finite discrete jumps. Both the finite and infinite horizon cases are considered. These results generalize the existed bounded real lemma for linear systems. 展开更多
关键词 bounded real LEMMA SAMPLED-DATA systems RICCATI EQUATIONS
下载PDF
Stochastic bounded consensus of second-order multi-agent systems in noisy environment 被引量:1
20
作者 任红卫 邓飞其 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第10期112-121,共10页
This paper investigates the stochastic bounded consensus of leader-following second-order multi-agent systems in a noisy environment. It is assumed that each agent received the information of its neighbors corrupted b... This paper investigates the stochastic bounded consensus of leader-following second-order multi-agent systems in a noisy environment. It is assumed that each agent received the information of its neighbors corrupted by noises and time delays. Based on the graph theory, stochastic tools, and the Lyapunov function method, we derive the sufficient conditions under which the systems would reach stochastic bounded consensus in mean square with the protocol we designed. Finally, a numerical simulation is illustrated to check the effectiveness of the proposed algorithms. 展开更多
关键词 stochastic bounded consensus multi-agent systems NOISES TIME-DELAYS
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部