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1.
归一化实数编码的多维并行遗传算法   总被引:7,自引:0,他引:7  
廖平 《计算机仿真》2005,22(10):122-124
给出了归一化多维实数编码的基本定义,并在此基础上提出了基于归一化实数编码的多维并行遗传算法;对归一化实数编码多维并行交叉算子、多维并行变异算子进行了详细的研究;提出了多维优化问题归一化实数编码长度计算公式;对遗传算法的控制参数确定进行了阐述;对归一化实数编码的多维并行遗传算法适应度函数的确定方法进行了研究.实验表明,归一化实数编码多维并行遗传算法可以大大提高多维优化问题的收敛速度,从而进一步提高算法的性能,这些特点对于计算复杂的非线性多维优化问题具有重要的意义.  相似文献   

2.
为了提高小世界算法的高维模型优化性能和降低算法的编码复杂性,提出了一种基于精英集聚效应的自适应实数编码小世界优化算法。该算法借鉴小世界现象进行网络空间搜索,包括随机长连接和局部短连接。为了提高优化性能,首先基于精英集聚效应在长连接中加入分级个体吸引策略;然后根据节点优化优劣在短连接中进行搜索次数及邻域大小的自适应调整。为了降低编码复杂性采用了实数编码。最后通过Markov链理论证明了算法的收敛性。数值测试结果表明,与禁忌遗传算法、基本小世界算法以及禁忌小世界算法相比,该算法在相对误差方面平均降低了30.3%,在收敛速度和稳定性方面分别平均提高了18.2%和13.8%,从而验证了算法的有效性。  相似文献   

3.
针对具有连续解空间的数值函数优化问题,基于量子算法和实数编码进化算法的思想,提出一种新的相位角编码量子进化算法(PAQEA).算法的概率表达特性使得量子染色体能够以一定概率表达优化问题的所有可行解,结合动态量子旋转门实现染色体的进化,实现了算法局部搜索与全局搜索的平衡.理论分析证明了算法的全局收敛性.仿真结果表明,该算法适用于复杂数值函数优化问题,具有收敛速度快、搜索能力强和稳定性高的特点.  相似文献   

4.
分析了遗传算法的二进制、实数、十进制编码策略实现方法,根据各编码的特点,设计了相应的改进遗传策略。以前馈神经网络权值优化问题为例,用计算机仿真实验的方法研究了三种编码策略对各遗传算法性能的影响。研究结果表明,若同时强调搜索效率和搜索准确性,宜采用实数编码的改进遗传算法;若只强调搜索准确性,则应优先考虑十进制编码的改进遗传算法。研究的结论为遗传算法在高维连续参数优化问题中编码策略的选取提供了理论指导。  相似文献   

5.
李鹏  董聪 《控制与决策》2002,17(4):487-490
对遗传算法中一些具有代表性的算法作了简要分析和评论,在此基础上将实数编码引入广义遗传算法,给出了一个算法框架,设计了相应的遗传操作方法,并将该算法应用于函数优化问题和神经网络训练问题,数值算例表明,该方法具有全局优化功能和快速收敛特性,对于求解复杂优化问题具有广泛的适用性。  相似文献   

6.
基于遗传算法的函数型小波网络   总被引:1,自引:1,他引:0  
陈健  谭阳红  尹新  周野 《计算机仿真》2010,27(2):180-183,268
针对传统小波神经网络易陷入局部极小等缺陷,采用遗传算法对神经网络进行优化。提出了一种结合实数编码与二进制编码的多值编码遗传算法,上述算法在同一条染色体上同时使用实数编码与二进制编码,有机结合了两者的优点,并把遗传算法用于优化函数型小波网络的结构中,可获得具有更好泛化能力的小波网络。仿真实验结果表明,利用该遗传算法训练小波神经网络,能使网络具有简单的结构形式,较高的逼近精度和较强的泛化能力,并证实了网络的有效性和优越性能。  相似文献   

7.
遗传算法的编码理论与应用   总被引:22,自引:0,他引:22  
编码是遗传算法求解问题的前提,文章分析了二进制编码、格雷码编码、实数编码、符号编码、排列编码、二倍体编码、DNA编码、混合编码、二维染色体编码或矩阵编码等编码的实质内容,在树编码和可变长编码基础上阐述了自适应编码的基本理论,提出了基于相似度的可变长编码和基于结构的agent编码方式,给出了函数优化、TSP、KP、JSP、机器人路径规划、图的划分和倒立摆等典型优化问题的编码方案。  相似文献   

8.
研究粒子群优化算法.传统的粒子群算法采用实数编码,收敛速度慢.为了提高收敛速度,提出了一种混沌编码的粒子群优化算法.混沌编码作为一种全新的数学编码方式,更能准确地表达编码对象的多样性,将混沌编码应用到粒子群优化算法中,使算法在初期的搜索区域更大,更快找到全局最优解.把混沌编码的粒子群算法与BP算法相结合用来优化神经网络.利用混沌编码的粒子群算法快速找到全局最优位置的邻域,然后再用BP算法进行局部寻优,收敛到全局最优位置.仿真结果证明混沌编码的粒子群神经网络比实数编码的粒子群神经网络分类收敛速度更快,验证了算法的有效性.  相似文献   

9.
实数编码遗传算法中交叉操作的效率分析   总被引:17,自引:2,他引:17  
介绍了常用的实数编码遗传算法及相应的交叉操作策略,通过理论分析和模拟实验研究了不同实数编码交叉操作的搜索效率。提出两种改进的交叉操作——有效线性交叉操作和张弛线性交叉操作,使子代个体在搜索空间内达到均匀分布,提高了遗传算法的优化效率  相似文献   

10.
陈小锋  史忠科 《计算机仿真》2010,27(7):262-266,298
针对包含不等式约束和等式约束的城市单交叉路口信号优化问题,为缓解交通堵塞和安全性,设计了一种混合优化方法.方法首先采用自适应惩罚策略,将具有不等式约束和等式约束的优化问题转变为仅包含决策变量上、下限约束的优化问题;然后再分别采用自适应实数编码遗传算法和一种变搜索空间局部搜索算法进行混合优化,为了提高实数编码遗传算法的优化效果,设计了一种自适应交叉概率和变异概率.最后针对多种交通需求模式,应用混合优化方法进行了大量的仿真计算,结果表明在城市单交叉路口信号优化问题中具有良好的优化效果.  相似文献   

11.
Despite all the financial resources that are directed to support and acquire learning technologies, the results have been generally disappointing. Faculty are eager to use technology but lack the technical skills, ability, and experience. Library staff includes a talent tool rich in Information and Communication Technologies (ICT)/WEB 2.0 technical expertise and experience. In terms of content sourcing and procurement, library technical services and selection staff have broad knowledge of the marketplace for online information and content as well as experience in licensing access. They have a firm grasp of the transaction process, workflows, pricing, and licensing negotiations. Content development and sourcing inevitably involves access management, online storage, copyright, and licensing—things at which libraries are good. ICT deployment is changing teaching and learning on campuses, and the roles of those involved in teaching and learning are also changing. Whether formally through mandated library services, or informally through back channels, library staff are supporting faculty new technology use as well as faculty teaching materials content sourcing and procurement.  相似文献   

12.
社会Agent的BDO模型   总被引:15,自引:0,他引:15  
目前MAS中思维状态的研究趋势是在个体模型中加入社会思维属性,研究社会承诺、依赖、联合意图的推理关系。在BDI模型中,以意图为中心的观点不描述社会Agent。该文分析了以竭力为中心的Agent思维状态研究存在的问题,提出MAS的分层模型,并提出以信念、愿望和义务作为基本思维属性(简称BDO)来描述Agent的思维状态和社会属性,给出了BDO逻辑和语义模型,考虑了奖励、惩罚、承诺和承诺解除问题,并对队、组织、组织意图等现象给出了描述。该文力图更自然地描述社会性Agent的思维状态和群体概念,是对Rao和Georgeff提出的BDI模型的改进。最后通过一个例子说明了BDO的表达能力。进一步的工作包括建立更为完善的语义模型、结合各个思维属性的动态修正语义给出BDO Agent的动态模型以及给出基于BDO逻辑框架的Agent/MAS实现结构。  相似文献   

13.
《Ergonomics》2012,55(12):1597-1618
Although often suggested as a control measure to alleviate musculoskeletal stresses, the use of mechanical assistance devices (i.e. manipulators) in load transfers has not been extensively studied. Without data describing the biomechanical effects of such devices, justification for decisions regarding implementation of such tools is difficult. An experimental study of two types of mechanical manipulators (articulated arm and overhead hoist) was conducted to determine whether biomechanical stresses, and hence injury risk, would be alleviated. Short distance transfers of loads with moderate mass were performed both manually and with manipulator assistance under a variety of task conditions. Using analysis and output from new dynamic torso models, strength demands at the shoulders and low back, lumbar spine forces, and lumbar muscle antagonism were determined. Strength requirements decreased significantly at both the shoulders and low back when using either manipulator in comparison with similar transfers performed manually. Peak spine compression and anteriorposterior (a-p) shear forces were reduced by about 40% on average, and these reductions were shown to be primarily caused by decreases in hand forces and resultant spinal moments. Two metrics of muscular antagonism were defined, and analysis showed that torso muscle antagonism was largest overall when using the hoist. The results overall suggest that hoist-assisted transfers, although better in reducing spine compression forces, may impose relatively higher demands on coordination and/or stability at extreme heights or with torso twisting motions. The relatively higher strength requirements and spine compression associated with the articulated arm may be a result of the high inertia of the system. Potential benefits of practice and training are discussed, and conclusions regarding implementation of mechanical manipulators are given.  相似文献   

14.
Emotions should play an important role in the design of interfaces because people interact with machines as if they were social actors. This paper presents a literature review on affective expressions through speech, music and body language. It summarizes the quality and quantity of their parameters and successful examples of synthesis. Moreover, a model for the convincingness of affective expressions, based on Fogg and Hsiang Tseng (1999), was developed and tested. The empirical data did not support the original model and therefore this paper proposes a new model, which is based on appropriateness and intensity of the expressions. Furthermore, the experiment investigated if the type of emotion (happiness, sadness, anger, surprise, fear and disgust), knowledge about the source (human or machine), the level of abstraction (natural face, computer rendered face and matrix face) and medium of presentation (visual, audio/visual, audio) of an affective expression influences its convincingness and distinctness. Only the type of emotion and multimedia presentations had an effect on convincingness. The distinctness of an expression depends on the abstraction and the media through which it is presented.  相似文献   

15.
Algebraic pruning: a fast technique for curve and surface intersection   总被引:6,自引:0,他引:6  
Computing the intersection of parametric and algebraic curves and surfaces is a fundamental problem in computer graphics and geometric modeling. This problem has been extensively studied in the literature and different techniques based on subdivision, interval analysis and algebraic formulation are known. For low degree curves and surfaces algebraic methods are considered to be the fastest, whereas techniques based on subdivision and Bézier clipping perform better for higher degree intersections. In this paper, we introduce a new technique of algebraic pruning based on the algebraic approaches and eigenvalue formulation of the problem. The resulting algorithm corresponds to computing only selected eigenvalues in the domain of intersection. This is based on matrix formulation of the intersection problem, power iterations and geometric properties of Bézier curves and surfaces. The algorithm prunes the domain and converges to the solutions rapidly. It has been applied to intersection of parametric and algebraic curves, ray tracing and curve-surface intersections. The resulting algorithm compares favorably with earlier methods in terms of performance and accuracy.  相似文献   

16.
元宇宙是虚拟数字世界与真实物理世界无缝融合的新生态,近来引发了各界的广泛关注。区块链、人工智能、虚拟现实/增强现实及传感技术、移动通信及泛在计算等各种新型互联网技术愈发成熟,使元宇宙的进一步发展成为可能。关于元宇宙的研究主要涉及产业项目、基础设施、关键技术、隐私安全等方面,这些研究虽然涉及区块链技术,但未具体指出区块链应用于元宇宙的优势及具体应用方式。区块链技术不仅可以为元宇宙提供开放自由的去中心化环境,而且可以为其提供公平合理的数字资产分配机制。主要从区块链赋能元宇宙中数字身份和数字资产管理的角度出发,分析了元宇宙的发展历程和特征,讨论了元宇宙发展所需核心技术及面临的挑战。同时研究了区块链的关键技术,并从区块链的本质特征及与其他技术融合优势两个方面对区块链应用于元宇宙做可行性分析。进一步提出元宇宙生态体系架构,重点详细分析了基于区块链的自我主权身份管理模型、区块链-非同质化通证(NFT,non-fungible token)工作流程及其在元宇宙中的应用。结合区块链和元宇宙的最新研究进展,从基础设施、通信和计算资源管理机制、监管与隐私保护以及区块链可扩展和互操作性4个方面指出区块链应用于元宇宙将面临的挑战和未来的研究方向。  相似文献   

17.
网络安全与防范分析是近年来国内外研究的热点问题之一。攻击者的技术和手段越来越多样化和高明化。计算机网络攻击与防范的研充就变得越来越重要了。论述了计算机网络面临的各种安全威胁方法及安全防范技术手段,对这些攻击给出相应的防范措施,并对入侵检测系统存在的不足给出了解决方案。  相似文献   

18.
Philip   《Annual Reviews in Control》2007,31(2):221-239
Some history and modern practice of Process Control in metallurgical operations is reviewed. Clearly the early deliverables from the pioneer days in the 1950s through to the 1970s and early 1980s were under-appreciated. The discipline has since grown into a more visible, sophisticated and accepted practice as a result of the assembly of appropriately recruited and trained individuals and teams, who have successfully negotiated deliverable projects that impact all metallurgical performances beyond early milling processes. The skill set in these individuals and teams essentially includes organisational behaviour in addition to their specialist technical attributes. A strong network to internal and external specialists and experts is essential. Furthermore, instrumentation and control technology has improved immensely. The challenge in the current modern practice is to win support of senior management in operations for the project cost, schedule and deliverables of Process Control. Once gained, this acceptance then amounts to the logistics of project scope and delivery—a track record well-demonstrated by the Xstrata Process Control Group.  相似文献   

19.
多Agent系统模型及其应用   总被引:4,自引:1,他引:4  
文章提出了基于访问、感知和知识的多Agent系统模型。从特定环境中的Agents为完成一定的任务所应具备的能力的角度出发,引入了环境状态划分函数、感知函数以及状态转移函数等来对Agents和环境进行研究并建立系统模型。该模型是合理的、自然的。同时,它还区分外部环境与Agents环境中可访问的信息,Agents感知到的信息以及Agents知道的信息,并研究了系统的运行过程。接下来,通过具体的实例来说明模型的具体应用。最后进行总结并讨论了进一步的研究工作。  相似文献   

20.
目前的研究认为人工智能的核心是数据、算法和算力,但因素在形成人工智能系统过程中是必不可少的。论文针对人工系统中的数据、算力、算法和因素的各自作用,及其相互关系进行了探讨和论证。从人工系统的内涵出发,描述人工系统的发展过程,认为目前和今后的人工系统必将具有人工智能特征,而实现人工系统要充分考虑上述四方面的相互作用。研究结果表明:数据是人工系统辨识因素的基础,也是形成算法的基础;因素是人工系统控制自然系统的方法及算法所需变量;算法体现了因素与数据关系,可描述人工系统结构;算力是解算算法的能力,也需考虑数据和因素的特征。因此因素在人工系统建立过程中与数据、算法和算力具有相同的重要性。它们具有明显的作用关系,且普遍存在于各个学科,是形成各学科理论基础体系的关键。  相似文献   

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