首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
徐川育 《信息与控制》1997,26(4):266-271
针对即使是全局收敛的变型标准遗传算法VCGA^[1]有时也会发生收敛速度变慢的问题,提出了VCGA和最陡下降法相结合的混合法HVCSDA。该方法增强了VCGA在接近全局最优解时的微调能力。还将HVCSDA推广到一类修正的VCGA上。仿真实例表明了HVCSDA及其推广能的效地提高收敛速度。对30城市TSP的仿真结果为6.822,要好于用TABU得到的6.99的结果[6]  相似文献   

2.
解决一类遗传算法早熟收敛的混合法及其推广   总被引:10,自引:0,他引:10  
徐川育 《软件学报》1998,9(3):231-235
本文分析了变型标准遗传算法VCGA(variantsofcanonicalgeneticalgorithms)有时会产生早熟收敛的机理,提出了混合法HVCSDA(hybridVCGAcombinedwithsteepestdescentapproach),并进行了推广.该方法可使最优保存的超级个体时间序列离开早熟收敛状态而继续接近全局最优解.仿真实例表明了本文算法的有效性.在30城市TSP(travelingsalesmanproblem)的基准测试问题中,本文得到了路径为6.82的结果,它好于用新的现代的启发式搜索方法——TABU搜索法得到的6.99的结果.  相似文献   

3.
《电脑》2002,(2)
ECS精英 K7S6A V1.0X主板最新BIOS 01/15/2002版新增支持 Athlon XP 2000+处理器,增加了 USB唤醒功能,修正了在安装Win98时,USB键盘不能使用热键的问题[182K]ECS精英 P6VXAT V1.0X主板最新 BIOS1.0b版修正了与 Tulatin1.2G CPU的兼容性问题 [202K]下载:www.ecs.com.twAsus华硕P45333主板(无板载网路及声音芯片)最新BIOS 1003C版[179K]华硕A7V266-E/AA主板(无板载网络及声音…  相似文献   

4.
C P U:AMDK6-2400 Socket7接口/散装主板:奔驰 k6Ⅲ150a VIA VT82C598MVP/ATX/Super 7/1M CACHE/ UDMA/66硬盘: DeskStarGXP/DJNA371350 13.5G/ UDMA/66/2M/7200rpm/IDE/全国联保三年内存:ACER(宏基)AM1/64M8ns/168PIN SDREM/PC100显示卡: 3dfx Voodoo3 2000 Voodoo3/16M SDRAM/AGP 2x声卡:雅马哈YAMAHA724/32硬波表…  相似文献   

5.
EIKI     
EIKI LC-NB1W分辨率 SVGA 800*600支持XGA光源亮度 900ANSI 160W UHP 3000H重量 3.9kgEIKI LC-870分辨率 SVGA 800*600支持XGA光源亮度 1250ANSI 160W UHP 3000H重量 6.6kgEIKI  相似文献   

6.
1.引 言 众所周知,TVD格式是能够高质量地捕捉激波的方法,但在计算粘性绕流时许多TVD格式数值耗散太大,不能正确模拟粘性流动,因而无法正确计算热流值.文献[3]指出,采用高精度格式可适当放松对网格雷诺数的要求,因此发展三阶或三阶以上的格式是需要的.文献[4]研究了迎风紧致群速度控制格式(UCGVC格式)在 Euler方程中的应用,提高了对激波的分辨率,优于通常二阶精度TVD格式.本文在文献[4]的基础上给出了利用迎风紧致格式求解NS方程.它是UCGVC格式在粘性流计算中的推广.对于方程中的无粘…  相似文献   

7.
2-D SHAPE BLENDING OF NURBS CURVE SHAPES   总被引:2,自引:0,他引:2  
2-DSHAPEBLENDINGOFNURBSCURVESHAPESJinXiaogang;BaoHujun;PengQunsheng2-DSHAPEBLENDINGOFNURBSCURVESHAPES¥JinXiaogang;BaoHujun;Pe...  相似文献   

8.
CURVEANDSURFACEINTERPOLATIONBYSUBDIVISIONALGORITHMSRuibinQuCURVEANDSURFACEINTERPOLATIONBYSUBDIVISIONALGORITHMS¥RuibinQuAbstra...  相似文献   

9.
禁止管理共享 [HKEY-LOCAL-MACHINE\ SYSTEM\ CurrentCon- troISet\Services\LanmanServer\Parmeters] AutoShareServer”= dword: 00000000 关闭ntfs 8.3短文件名 [ HKEY-LOCAL-MACHINE\ SYSTEM\ CurrentCon- trolSet\Control\Filesysteml NtfsDisable8dot3NameGeneration”=dword: 00000001 限制…  相似文献   

10.
带有变量中误差的Logit回归模型及其计算   总被引:3,自引:0,他引:3  
带有变量中误差的Logit回归模型及其计算吕纯濂,陈舜华(南京气象学院)H.Kuchenhoff(慕尼黑大学统计与科学理论研究所)THELOGITREGRESSIONMODELWITHERRORS-IN-VARIABLESANDITSCALCULAT...  相似文献   

11.
In this paper, both general and exponential bounds of the distance between a uniform Catmull-Clark surface and its control polyhedron are derived. The exponential bound is independent of the process of subdivision and can be evaluated without recursive subdivision. Based on the exponential bound, we can predict the depth of subdivision within a user-specified error tolerance. This is quite useful and important for pre-computing the subdivision depth of subdivision surfaces in many engineering applications such as surface/surface intersection,mesh generation, numerical control machining and surface rendering.  相似文献   

12.
在预测领域中应用模糊控制的研究   总被引:1,自引:0,他引:1  
张昊  郁滨  吴捷 《自动化学报》1999,25(5):620-626
预测问题在科学技术领域中有着广泛的应用背景.提出了将基于误差反馈和专家经 验的闭环模糊控制引入预测系统,用于修正预测输出、提高预测精度和鲁棒性的设想.以电力 负荷预测为背景,进行了一系列实验研究,结果证明在预测领域中应用模糊控制是有效的,从 而为其它控制方法在预测领域的应用研究开辟了前景.  相似文献   

13.
非线性控制在电力系统中的应用   总被引:7,自引:0,他引:7  
对多种非线性控制技术的基本原理进行了简要的介绍,在此基础上结合电力系统的具体特性介绍了它们在电力系统中的一些具体应用.最后,指出了电力系统非线性控制的发展趋势.  相似文献   

14.
非线性控制在电力系统中的应用   总被引:8,自引:0,他引:8       下载免费PDF全文
对多种非线性控制技术的基本原理进行了简要的介绍, 在此基础上结合电力系统的具体特性介绍了它们在电力系统中的一些具体应用. 最后, 指出了电力系统非线性控制的发展趋势.  相似文献   

15.
针对非自衡化工过程难以控制及所得控制器参数调节无规律可循的问题,为提高过程控制品质,通过设计跟踪给定值控制回路和抑制干扰控制回路来实现非自衡化工过程的控制;利用最优控制理论、Taylor近似,设计得到的跟踪给定值控制器和抑制干扰控制器其PID参数可解析给出,每个控制器只有唯一的调节参数且两个回路的参数调节相互独立,最后定性分析了闭环控制系统的稳定性,仿真结果表明基于该控制系统可有效实现非自衡化工过程的控制。  相似文献   

16.
TCP吞吐率模型及其应用范例   总被引:1,自引:0,他引:1       下载免费PDF全文
在因特网中,TCP协议是使用最多的传输控制协议,包括FTP、WWW和SMTP在内的大量应用都使用TCP作为底层传输协议。对TCP建模具有很重要的意义,可以让我们更加深入地了解TCP的性能;同时,TCP模型还具有其它一些重要的应用,比如TCP友好的拥塞控制、主动队列管理算法参数设置等。本文列举了几个应用TCP吞吐率模型的典型范例,通过这些应用可以看出,TCP模型是一个用于拥塞控制系统分析和设计的有力工具。  相似文献   

17.
Many practical engineering applications require various types of fuzzy logic systems (FLSs) to design adaptive controllers for nonlinear systems with uncertainties. In this article, we will consider a fundamental theoretical question: is it possible to find a unified adaptive control design method suited to various types of FLSs? In order to solve this problem, we will introduce scalers and saturators at the input and output terminals of FLSs to form the extended FLSs (EFLS). The scalers and saturators have adjustable parameters. By designing the updated laws of these parameters and the estimate values of the fuzzy approximate accuracies, stable adaptive fuzzy controllers can be realised for a class of nonlinear systems with unknown homogeneous drift functions and gains. The proposed design method is only dependent on the outputs of EFLS and the above updated laws, thus increasing its adaptability. The fuzzy control scheme introduced in this article is suitable for all fuzzy systems with or without fuzzy rules. Simulations will also be used to show the validity of the method proposed in this article.  相似文献   

18.
The paper proposes a flexible layered control policy for sensor resource allocation in a sensor grid. In order to allocate sensor resources in the system to maximize the sensor grid utility, different controllers are deployed at three levels: a job-level controller, an application group controller, and a sensor grid system controller. At the lowest levels, job-level controllers perform fast, frequent, local adaptation for optimizing a single sensor grid application at a time, while, at the highest levels, sensor grid system controllers perform less frequent control actions to optimize all applications. Sensor grid system control considers all sensor grid applications in response to large system changes at coarse time granularity. Sensor grid system control exploits the interlayer coupling of the resource layer and the application layer to achieve a system-wide optimization based on the sensor grid users’ preferences. Job-level control adapts a single application to small changes at fine granularity. The layered control system uses a set of utility functions to evaluate the performance of sensor grid applications and groups. The control system chooses control actions that would result in a higher level of utility. In the simulation, a performance evaluation of the algorithm is carried out.  相似文献   

19.
We consider the adaptive tracking problem for a chain of integrators, where the uncertainty is static and functional. The uncertainty is specified by L 2/L or weighted L 2/L norm bounds. We analyse a standard Lyapunov-based adaptive design which utilises a function approximator to induce a parametric uncertainty, on which the adaptive design is completed. Performance is measured by a modified LQ cost functional, penalising both the tracking error transient and the control effort. With such a cost functional, it is shown that a standard control design has divergent performance when the resolution of a “mono-resolution” approximator is increased. The class of “mono-resolution” approximators includes models popular in applications. A general construction of a class of approximators and their associated controllers which have a uniformly bounded performance independent of the resolution of the approximator is given. Date received: 20 April 1999. Date revised: 29 October 2001.  相似文献   

20.
本文提出的云控制系统(Cloud control systems, CCSs)是对之前的网络化控制系统(Networked control systems, NCSs)的进一步扩展.目前,物联网(Internet of things, IOT)已经成功应用于实际中,网络化控制技术在其中发挥了关键作用.与此同时,云计算的迅速发展为大数据存储与处理、控制器设计和控制系统性能优化提供了一个完美的平台.可以预见,虽然当前云控制技术的研究和应用还存在许多挑战,但在不久的将来,云控制系统的深入研究将对控制理论的发展和各种实际应用起到积极推动作用.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号