期刊文献+
共找到2,631篇文章
< 1 2 132 >
每页显示 20 50 100
Scheduling Rules Based on Gene Expression Programming for Resource-Constrained Project Scheduling Problem 被引量:3
1
作者 贾艳 李晋航 《Journal of Donghua University(English Edition)》 EI CAS 2015年第1期91-96,共6页
In order to minimize the project duration of resourceconstrained project scheduling problem( RCPSP), a gene expression programming-based scheduling rule( GEP-SR) method is proposed to automatically discover and select... In order to minimize the project duration of resourceconstrained project scheduling problem( RCPSP), a gene expression programming-based scheduling rule( GEP-SR) method is proposed to automatically discover and select the effective scheduling rules( SRs) which are constructed using the project status and attributes of the activities. SRs are represented by the chromosomes of GEP, and an improved parallel schedule generation scheme( IPSGS) is used to transform the SRs into explicit schedules. The framework of GEP-SR for RCPSP is designed,and the effectiveness of the GEP-SR approach is demonstrated by comparing with other methods on the same instances. 展开更多
关键词 resource-constrained project scheduling problem(RCPSP) gene expression programming(GEP) scheduling rules(SRs)
下载PDF
A New Algorithm for Resource Constraint Project Scheduling Problem Based on Multi-Agent Systems 被引量:1
2
作者 何曙光 齐二石 李钢 《Transactions of Tianjin University》 EI CAS 2003年第4期348-352,共5页
The resource constrained project scheduling problem (RCPSP) and a decision-making model based on multi-agent systems (MAS) and general equilibrium marketing are proposed. An algorithm leading to the resource allocatio... The resource constrained project scheduling problem (RCPSP) and a decision-making model based on multi-agent systems (MAS) and general equilibrium marketing are proposed. An algorithm leading to the resource allocation decision involved in RCPSP has also been developed. And this algorithm can be used in the multi-project scheduling field as well.Finally, an illustration is given. 展开更多
关键词 resource constrained project scheduling problem multi-agent systems general equilibrium market ALGORITHM
下载PDF
ON THE MONOTONE CONVERGENCE OF THE PROJECTED ITERATION METHODS FOR LINEAR COMPLEMENTARITY PROBLEMS 被引量:3
3
作者 白中治 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 1996年第2期228-233,共6页
Under suitable conditions,the monotone convergence about the projected iteration method for solving linear complementarity problem is proved and the influence of the involved parameter matrix on the convergence rate o... Under suitable conditions,the monotone convergence about the projected iteration method for solving linear complementarity problem is proved and the influence of the involved parameter matrix on the convergence rate of this method is investigated. 展开更多
关键词 LINEAR complementarity problem projected ITERATION method MONOTONE convergence.
下载PDF
Projection and Contraction Methods for Nonlinear Complementarity Problem 被引量:2
4
作者 Zhao She-feng, Fei Pu-sheng College of Mathematics and Computer Science,Wuhan University,Wuhan 430072,China 《Wuhan University Journal of Natural Sciences》 EI CAS 2000年第4期391-396,共6页
We applied the projection and contraction method to nonlinear complementarity problem (NCP). Moveover, we proposed an inexact implicit method for (NCP) and proved the convergence.
关键词 nonlinear complementarity problem projection and contraction method implicit method
下载PDF
Application for Superconvergence of Finite Element Approximations for the Elliptic Problem by Global and Local L<sup>2</sup>-Projection Methods 被引量:1
5
作者 Rabeea H. Jari Lin Mu 《American Journal of Computational Mathematics》 2012年第4期249-257,共9页
Numerical experiments are given to verify the theoretical results for superconvergence of the elliptic problem by global and local L2-Projection methods.
关键词 FINITE Element Methods SUPERCONVERGENCE L2-projection ELLIPTIC problem
下载PDF
Approximate subgradient projection algorithm for convex feasibility problem 被引量:1
6
作者 Li Li Yan Gao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第3期527-530,共4页
An ε-subgradient projection algorithm for solving a convex feasibility problem is presented.Based on the iterative projection methods and the notion of ε-subgradient,a series of special projection hyperplanes is est... An ε-subgradient projection algorithm for solving a convex feasibility problem is presented.Based on the iterative projection methods and the notion of ε-subgradient,a series of special projection hyperplanes is established.Moreover,compared with the existing projection hyperplanes methods with subgradient,the proposed hyperplanes are interactive with ε,and their ranges are more larger.The convergence of the proposed algorithm is given under some mild conditions,and the validity of the algorithm is proved by the numerical test. 展开更多
关键词 ε-subgradient projection algorithm convex feasibility problem.
下载PDF
An iterative virtual projection method to improve the reconstruction performance for ill-posed emission tomographic problems 被引量:1
7
作者 柳华蔚 郑树 周怀春 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第10期200-212,共13页
In order to improve the reconstruction performance for ill-posed emission tomographic problems with limited projections, a generalized interpolation method is proposed in this paper, in which the virtual lines of proj... In order to improve the reconstruction performance for ill-posed emission tomographic problems with limited projections, a generalized interpolation method is proposed in this paper, in which the virtual lines of projection are fabricated from, but not linearly dependent on, the measured projections. The method is called the virtual projection(VP) method.Also, an iterative correction method for the integral lengths is proposed to reduce the error brought about by the virtual lines of projection. The combination of the two methods is called the iterative virtual projection(IVP) method. Based on a scheme of equilateral triangle plane meshes and a six asymmetrically arranged detection system, numerical simulations and experimental verification are conducted. Simulation results obtained by using a non-negative linear least squares method,without any other constraints or regularization, demonstrate that the VP method can gradually reduce the reconstruction error and converges to the desired one by fabricating additional effective projections. When the mean square deviation of normal error superimposed on the simulated measured projections is smaller than 0.03, i.e., the signal-to-noise ratio(SNR)for the measured projections is higher than 30.4, the IVP method can further reduce the reconstruction error reached by the VP method apparently. In addition, as the regularization matrix in the Tikhonov regularization method is updated by an iterative correction process similar to the IVP method presented in this paper, or the Tikhonov regularization method is used in the IVP method, good improvement is achieved. 展开更多
关键词 ill-posed problem emission tomography limited projections Tikhonov regularization
下载PDF
Solving resource availability cost problem in project scheduling by pseudo particle swarm optimization 被引量:4
8
作者 Jianjun Qi Bo Guo +1 位作者 Hongtao Lei Tao Zhang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第1期69-76,共8页
This paper considers a project scheduling problem with the objective of minimizing resource availability costs appealed to finish al activities before the deadline. There are finish-start type precedence relations amo... This paper considers a project scheduling problem with the objective of minimizing resource availability costs appealed to finish al activities before the deadline. There are finish-start type precedence relations among the activities which require some kinds of renewable resources. We predigest the process of sol-ving the resource availability cost problem (RACP) by using start time of each activity to code the schedule. Then, a novel heuris-tic algorithm is proposed to make the process of looking for the best solution efficiently. And then pseudo particle swarm optimiza-tion (PPSO) combined with PSO and path relinking procedure is presented to solve the RACP. Final y, comparative computational experiments are designed and the computational results show that the proposed method is very effective to solve RACP. 展开更多
关键词 project scheduling resource availability cost problem(RACP) HEURISTICS particle swarm optimization (PSO) path relin-king.
下载PDF
Project Scheduling Problem with Uncertain Variables
9
作者 Liang Lin Ting Lou Ni Zhan 《Applied Mathematics》 2014年第4期685-690,共6页
Project scheduling problem is mainly to determine the schedule of allocating resources in order to balance the total cost and the completion time. This paper chiefly uses chance theory to introduce project scheduling ... Project scheduling problem is mainly to determine the schedule of allocating resources in order to balance the total cost and the completion time. This paper chiefly uses chance theory to introduce project scheduling problem with uncertain variables. First, two types of single-objective programming models with uncertain variables as uncertain chance-constrained model and uncertain maximization chance-constrained model are established to meet different management requirements, then they are extended to multi-objective programming model with uncertain variables. 展开更多
关键词 project SCHEDULING problem UNCERTAIN VARIABLE Single-Objective PROGRAMMING MULTI-OBJECTIVE PROGRAMMING
下载PDF
A Modified Projection Method for Linear Feasibility Problems
10
作者 Yi-Ju Wang Hong-Yu Zhang 《International Journal of Automation and computing》 EI 2009年第4期401-405,共5页
In this paper, we present a modified projection method for the linear feasibility problems (LFP). Compared with the existing methods, the new method adopts a surrogate technique to obtain new iteration instead of th... In this paper, we present a modified projection method for the linear feasibility problems (LFP). Compared with the existing methods, the new method adopts a surrogate technique to obtain new iteration instead of the line search procedure with fixed stepsize. For the new method, we first show its global convergence under the condition that the solution set is nonempty, and then establish its linear convergence rate. Preliminary numerical experiments show that this method has good performance. 展开更多
关键词 Linear feasibility problem (LFP) projection method global convergence convergence rate computational experiments
下载PDF
Reduced projection augmented Lagrange bi-conjugate gradient method for contact and impact problems
11
作者 李南生 任魁生 沙德松 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2007年第8期1101-1108,共8页
Based on the numerical governing formulation and non-linear complementary conditions of contact and impact problems, a reduced projection augmented Lagrange bi- conjugate gradient method is proposed for contact and im... Based on the numerical governing formulation and non-linear complementary conditions of contact and impact problems, a reduced projection augmented Lagrange bi- conjugate gradient method is proposed for contact and impact problems by translating non-linear complementary conditions into equivalent formulation of non-linear program- ming. For contact-impact problems, a larger time-step can be adopted arriving at numer- ical convergence compared with penalty method. By establishment of the impact-contact formulations which are equivalent with original non-linear complementary conditions, a reduced projection augmented Lagrange bi-conjugate gradient method is deduced to im- prove precision and efficiency of numerical solutions. A numerical example shows that the algorithm we suggested is valid and exact. 展开更多
关键词 contact and impact problems reduced projection augmented Lagrange bi-conjugate gradient numerical method
下载PDF
Arnoldi Projection Fractional Tikhonov for Large Scale Ill-Posed Problems 被引量:1
12
作者 Wang Zhengsheng Mu Liming +1 位作者 Liu Rongrong Xu Guili 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2018年第3期395-402,共8页
It is well known that Tikhonov regularization in standard form may determine approximate solutions that are too smooth for ill-posed problems,so fractional Tikhonov methods have been introduced to remedy this shortcom... It is well known that Tikhonov regularization in standard form may determine approximate solutions that are too smooth for ill-posed problems,so fractional Tikhonov methods have been introduced to remedy this shortcoming.And Tikhonov regularization for large-scale linear ill-posed problems is commonly implemented by determining apartial Arnoldi decomposition of the given matrix.In this paper,we propose a new method to compute an approximate solution of large scale linear discrete ill-posed problems which applies projection fractional Tikhonov regularization in Krylov subspace via Arnoldi process.The projection fractional Tikhonov regularization combines the fractional matrices and orthogonal projection operators.A suitable value of the regularization parameter is determined by the discrepancy principle.Numerical examples with application to image restoration are carried out to examine that the performance of the method. 展开更多
关键词 ill-posed problems fractional matrix Tikhonov regularization orthogonal projection operator image restoration
下载PDF
KEY S&T PROBLEMS RELATED TO THE THREE GORGES PROJECT
13
作者 Zhang Guangdou(Tsinghua University)Pan Jiazheng(Ministry of Electrical Power Industry) 《Bulletin of the Chinese Academy of Sciences》 1996年第2期127-135,共9页
This article gives a highly capsulized introduction to the research on key S&T problems involving geology, silting-up, hydropower facilities, navigation locks and shiplift, construction technology, and eco-environ... This article gives a highly capsulized introduction to the research on key S&T problems involving geology, silting-up, hydropower facilities, navigation locks and shiplift, construction technology, and eco-environ-mental con-sequences in the Three Gorges Project on the Yangtze River. 展开更多
关键词 KEY S&T problemS RELATED TO THE THREE GORGES project project
下载PDF
EXTENDED OBLIQUE PROJECTION METHOD FOR GENERALIZED LEAST SQUARES PROBLEM
14
作者 黄开斌 颜世建 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 1994年第2期195-201,共7页
We extend the oblique projection method given by Y.Saad to solve the generalized least squares problem. The corresponding oblique projection operator is presented and the convergence theorems are proved. Some necessar... We extend the oblique projection method given by Y.Saad to solve the generalized least squares problem. The corresponding oblique projection operator is presented and the convergence theorems are proved. Some necessary and sufficient conditions for computing the solution or the minimum N-norm solution of the min || A x- b ||M2 have been proposed as well. 展开更多
关键词 OBLIQUE projection method GENERALIZED least SQUARES problem mini-norm least SQUARES solution GENERALIZED inverses.
下载PDF
RECURRENT NEURAL NETWORK MODEL BASED ON PROJECTIVE OPERATOR AND ITS APPLICATION TO OPTIMIZATION PROBLEMS
15
作者 马儒宁 陈天平 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2006年第4期543-554,共12页
The recurrent neural network (RNN) model based on projective operator was studied. Different from the former study, the value region of projective operator in the neural network in this paper is a general closed con... The recurrent neural network (RNN) model based on projective operator was studied. Different from the former study, the value region of projective operator in the neural network in this paper is a general closed convex subset of n-dimensional Euclidean space and it is not a compact convex set in general, that is, the value region of projective operator is probably unbounded. It was proved that the network has a global solution and its solution trajectory converges to some equilibrium set whenever objective function satisfies some conditions. After that, the model was applied to continuously differentiable optimization and nonlinear or implicit complementarity problems. In addition, simulation experiments confirm the efficiency of the RNN. 展开更多
关键词 recurrent neural network model projective operator global convergence OPTIMIZATION complementarity problems
下载PDF
中国人口老龄化的过去、现在和未来 被引量:9
16
作者 乔晓春 《社会政策研究》 2024年第1期47-63,133,共18页
从20世纪70年代初期开始的计划生育,使得中国妇女生育率快速下降,也预示着人口老龄化速度将在一定阶段明显加快。本文回顾了中国人口出生率和死亡率的下降过程,描述了以往不同时间点中国人口年龄结构的变化,利用2020年第七次全国人口普... 从20世纪70年代初期开始的计划生育,使得中国妇女生育率快速下降,也预示着人口老龄化速度将在一定阶段明显加快。本文回顾了中国人口出生率和死亡率的下降过程,描述了以往不同时间点中国人口年龄结构的变化,利用2020年第七次全国人口普查数据分析了老年人口的状况和特点,并对未来50年中国人口和老龄化进程进行了预测。研究发现:2022—2036年是老年人口增长最快的时期,2037—2051年进入中速增长阶段,2052—2063年老年人口增长速度迅速递减,从2056年开始老年人口出现负增长,老年人口数量有所减少。从2068年开始到未来的一段时间老年人口增长速度会在0附近波动,而且会长期保持下去。尽管老年人口出现负增长,但是老年人口所占比例仍然会持续上升,老龄化进程将大幅度减缓,这会在很大程度上缓解老龄化和老龄问题带来的压力。总之,未来30年是积极应对人口老龄化、解决老龄问题的关键时期。然而,与“30后”“40后”父母相比,“50后”“60后”“70后”父母现有子女数大幅度减少,家庭养老将难以为继,未来社会养老将面临巨大压力。 展开更多
关键词 人口老龄化 老龄问题 人口预测 增长速度 家庭养老
下载PDF
基于颠覆性技术创新项目评价及立项决策模型的研究
17
作者 陈之瑶 罗军 +1 位作者 莎薇 侯小星 《科技管理研究》 2024年第1期152-159,共8页
为实现我国颠覆性技术创新项目的精准遴选,促进颠覆性创新产业的培育发展,在分析梳理国内外关于颠覆性技术创新项目遴选、立项决策管理方面研究的基础上,分析对比颠覆性技术创新项目与一般科技计划项目的特征属性差异,借鉴海尔迈耶问题... 为实现我国颠覆性技术创新项目的精准遴选,促进颠覆性创新产业的培育发展,在分析梳理国内外关于颠覆性技术创新项目遴选、立项决策管理方面研究的基础上,分析对比颠覆性技术创新项目与一般科技计划项目的特征属性差异,借鉴海尔迈耶问题的做法,结合当前政策导向,针对颠覆性技术具有隐蔽性、破坏性、不确定性的特征属性,提出相应的项目遴选角度和评审标准的思路,并利用层次分析法构建颠覆性技术创新项目立项评价的三级指标体系。从项目影响力、项目可能性两方面构建颠覆性技术创新项目的决策矩阵模型,为颠覆性创新项目立项决策提供判断依据。 展开更多
关键词 颠覆性技术创新项目 海尔迈耶问题 评价模型 决策模型
下载PDF
A New Conjugate Gradient Projection Method for Solving Stochastic Generalized Linear Complementarity Problems 被引量:2
18
作者 Zhimin Liu Shouqiang Du Ruiying Wang 《Journal of Applied Mathematics and Physics》 2016年第6期1024-1031,共8页
In this paper, a class of the stochastic generalized linear complementarity problems with finitely many elements is proposed for the first time. Based on the Fischer-Burmeister function, a new conjugate gradient proje... In this paper, a class of the stochastic generalized linear complementarity problems with finitely many elements is proposed for the first time. Based on the Fischer-Burmeister function, a new conjugate gradient projection method is given for solving the stochastic generalized linear complementarity problems. The global convergence of the conjugate gradient projection method is proved and the related numerical results are also reported. 展开更多
关键词 Stochastic Generalized Linear Complementarity problems Fischer-Burmeister Function Conjugate Gradient projection Method Global Convergence
下载PDF
面向学生创造力培养的语文项目化学习准实验研究 被引量:1
19
作者 夏雪梅 王湖滨 李倩云 《北京教育学院学报》 2024年第2期20-27,共8页
项目化学习是提升学生创造力的一条重要实施路径。学科领域的项目化学习是否可以提升学生的学科创造力以及在真实问题解决中的创造力?以上海市某公办小学四年级学生为研究对象,实施基于项目设计标准的语文写作类项目化学习,采用对照班... 项目化学习是提升学生创造力的一条重要实施路径。学科领域的项目化学习是否可以提升学生的学科创造力以及在真实问题解决中的创造力?以上海市某公办小学四年级学生为研究对象,实施基于项目设计标准的语文写作类项目化学习,采用对照班和实验班、前测和后测对比验证的准实验方法进行考察,结果表明:项目化学习实验班中学生的学科创造力、真实问题解决创造力显著优于对照班;学科项目对于学生学科创造力的提升可以迁移到真实问题解决创造力中。 展开更多
关键词 项目化学习 学科项目 学科创造力 真实问题解决
下载PDF
Establish Project Is Easy But To Implement Is Difficult --The Main Problems And Solutions Of Universities' Reform
20
作者 Fazhao Gao 《Journal of Zhouyi Research》 2014年第2期42-44,共3页
关键词 教学改革 中国经济 高技术战争 高等教育 立项 高校 高科技领域 市场经济
下载PDF
上一页 1 2 132 下一页 到第
使用帮助 返回顶部