共查询到20条相似文献,搜索用时 15 毫秒
1.
If we restrict the postman to traversing each edge at most twice in the windypostman problem (WPP), we will get a new problem: 2WPP. An approximation algorithmhas been posed by M. Guan for the WPP. In the present paper, we improve the estimatederror given by M. Guan and show that we can estimate the error for the 2WPP by findinga minimum cost circulation. We also pose a new sufficient condition for the equivalencebetween WPP and 2WPP, which can be checked in polynomial time steps. 相似文献
2.
1 IntroductionOptimal design or control is playing an increasingly importal role in engineering designwork. Efficient numerical methods are among the keys to successful application of optimalcontrol in practical work. With its wide range of application in scielltific and engineeringnumerical simulation, finite element approximation of optimal control problems plays a veryimportant role in numerical method of these problems. There have been eXtensive studies inthis respect, see, for example, [… 相似文献
3.
ZHENG Yufan CAO Li Applied Mathematics Research Laboratory East China Normal University Shanghai China 《系统科学与复杂性》1993,(3)
The notion of ranking was initiated into control theory by Glad a few yearsago. In this paper we mainly discuss one kind of rankings and study its invarianceproperties. This kind of rankings is closely related to the structure algorithm. The relationsbetween invariants of this kind of rankings and the invariants given by other studies, e.g.the invertibility indices of a system and so on, are examined. As applications of rankings,we deal with some well-known problems in "ranking technique". In this paper we mainlyintroduce a new method rather than solve new problems. 相似文献
4.
In this paper,we discuss the optimal control of growth rate for a class of population systems governed by nonlinear degenerate parabolic equations.Given an ap-propriate cost functional,we prove the existence of the optimal growth rate and give some necessary conditions for optimal growth rate. 相似文献
5.
本文研究连续边界条件系统的最优控制问题,给出了最优控制存在的必要条件,证明了该类最优控制仍有最大值原理成立。 相似文献
6.
MAXIMUM PRINCIPLE FOR OPTIMAL CONTROL PROBLEM OF FULLY COUPLEDFORWARD-BACKWARD STOCHASTIC SYSTEMS 总被引:1,自引:0,他引:1
WU Zhen 《系统科学与复杂性》1998,(3)
1.IntroductionLet(fi,F,P)beaprobabilityspaceand{Bt}tZobead-dimensionalBrownianmotioninthisspace.Let{R}tZobethenaturalfiltrationofthisBrownianmotion.Weconsiderthefollowingfullycoupledforward-backwardstochasticsystems:where(x,y,z)takesvaluesinRxacxRTnxd.LetUbeanonemptyconvexsubsetofR',Anelementofadiscalledanadmissiblecontrol.Wecandefinethefollowingcostfunction:TheoptimalcontrolproblemistominimizethecostfunctionJ(v(.))overadmissiblecontrols.Anadmissiblecontrolu(.)iscalledanoptimalcontrol… 相似文献
7.
DING Xiaqi 《系统科学与复杂性》1999,(Z1)
1.IntroductionThemostspecialfeatureofconservationlawsofhyperbolicsystemsisthattheirsolutionsalwayshavediscolltinuities.ThiskindofdiscontinuityrepresentstheshoCkwavephenomena.Sopeopleintroducetheideaofgeneralizedsolutionwhichsatisfiesequationsinthesenseofdistribution.Underthisdefinition,alotofachievementshavebeenobtainedsince1950'sinthisfield.However,inrecelltyears,manyauthors(see[l--6])discoveredthatthereisnoexistenceanduniqllenessofsolutionstoRiemannproblemsforsomeconservationlaws.Bynumeric… 相似文献
8.
LI Shurong 《系统科学与复杂性》1994,(3)
WU-RITT'SMETHODFORNONLINEARCONTROLSYSTEMS¥LIShurong(InstituteofSystemsScience,AcademiaSinica,Beijing100080,China)Abstract:Thi... 相似文献
9.
FENG Shaoji 《系统科学与复杂性》2001,(3)
1 IntroductionLet B be the uait ball of Cn with boundary S, u the Lebesgue measure on B normalized sothat u(B) = 1 and u the normalized rotation invarian measure on S, i.e. a(S) = 1. The classof all holomorphic functions will be denoted by H(B).Let f be i… 相似文献
10.
Stochastic adaptive control is considered for the discrete-time multi-input and multi-output system of multi-delay with noise expressed by an ARMA process.The CARIMA model isa special case of the system in question.The optimal adaptive control law is given and it is shown thata quadratic cost function is minimized and the closed-loop system is stable.Further,when the systemis of minimum phase,the convergence rates of parameter estimates and of the cost-function are alsoderived. 相似文献
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12.
XUDachuan 《系统科学与复杂性》2003,16(2):260-267
Using outward rotations, we obtain an approximation algorithm for MAX n/2-UNCUT problem, i.e., partitioning the vertices of a weighted graph into two blocks of equal cardinality such that the total weight of edges that do not cross the cut is maximized. In many interesting causes, the algorithm performs better than the algorithms of Ye and of Halperin and Zwick. The main tool used to obtain this result is semidefinite programming. 相似文献
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14.
王恩平 《系统科学与复杂性》1991,(3)
In this paper a local maximum principle for the singular discrete-time linear systemMx(k)=φx(k-1)+Bu(k-1)is investigated.By using this local maximum principle we can discussthe linear-quadratic optimal regulator problem and the minimum energy problem for singulardiscrete-time linear systems. 相似文献
15.
ZHOU Yong 《系统科学与复杂性》1996,(4)
STRONGAPPROXIMATIONFORPERTURBEDEMPIRICALPROCESSES¥ZHOUYong(DepartmentofProbabilityandStatistics,PekingUniversity,Beijing10087... 相似文献
16.
SUNBing GUOBaozhu 《系统科学与复杂性》2005,18(3):285-301
This paper is concerned with an optimal control problem of an ablationtranspiration cooling control system with Stefan-Signorini boundary condition. The existence of weak solution of the system is considered. The Dubovitskii and Milyutin approach is adopted in the investigation of the Pontryagin‘s maximum principle of the system. The optimality necessary condition is presented for the problem with fixed final horizon and phase constraints. 相似文献
17.
GAO Aijun 《系统科学与复杂性》1992,(3)
A multidimensional adaptive stochastic approximation procedure trun-cated at randomly varying bounds is studied for the regression function observedwith correlated noise.The algorithm is proved to be asymptotically efficient.Theresult of the paper generalizes the one shown in[1]for the observation noise be-ing i.i.d.random vectors and under other restrictive conditions imposed on theregression function. 相似文献
18.
CHENHanfu 《系统科学与复杂性》2003,16(3):315-326
The paper addresses optimization of a performance function which either is optimized via stabilizing and controlling the underlying unknown system or is directly optimized on the basis of its noise-corrupted observations. For the first case the unknown system is identified and then the indirect adaptive control approach is applied to optimize the performance function. For the second case the stochastic approximation method is used to optimize the objective function, and it appears that a number of problems arising from applications may be reduced to the one solvable by this approach. The paper demonstrates some basic results in the area, but with no intention to give a complete survey. 相似文献
19.
储德林 《系统科学与复杂性》1989,(2)
In this paper,a study of the characterization of fixed modes in decentralized control ismade.A new sufficient and necessary condition for the existence of fixed modes is obtained by meansof the generalized eigenvalue theory of matrix pairs,and the computability of the new condition ispresented.The results show that fixed modes can be computed in a reliable and efficient manner. 相似文献
20.
WEN Guochun 《系统科学与复杂性》1998,(4)
1.TheirregularObliqueDerivativeProblemanditsWell-PosednessforNonlinearEllipticSystemsLabDbean(N 1)-connectedboundeddomaininthez=x ic-planeCwithboundaryFECI(0
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