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991.
Practical industrial process is usually a dynamic process including uncertainty. Stochastic constraints can be used for industrial process modeling, when system sate and/or control input constraints cannot be strictly satisfied. Thus, optimal control of switched systems with stochastic constraints can be available to address practical industrial process problems with different modes. In general, obtaining an analytical solution of the optimal control problem is usually very difficult due to the discrete nature of the switching law and the complexity of stochastic constraints. To obtain a numerical solution, this problem is formulated as a constrained nonlinear parameter selection problem (CNPSP) based on a relaxation transformation (RT) technique, an adaptive sample approximation (ASA) method, a smooth approximation (SA) technique, and a control parameterization (CP) method. Following that, a penalty function-based random search (PFRS) algorithm is designed for solving the CNPSP based on a novel search rule-based penalty function (NSRPF) method and a novel random search (NRS) algorithm. The convergence results show that the proposed method is globally convergent. Finally, an optimal control problem in automobile test-driving with gear shifts (ATGS) is further extended to illustrate the effectiveness of the proposed method by taking into account some stochastic constraints. Numerical results show that compared with other typical methods, the proposed method is less conservative and can obtain a stable and robust performance when considering the small perturbations in initial system state. In addition, to balance the computation amount and the numerical solution accuracy, a tolerance setting method is also provided by the numerical analysis technique. 相似文献
992.
We address the problem of monitoring a linear functional (c, x)Eof an unknown vectorx of a Hilbert spaceE, the available data being the observationz, in a Hilbert spaceF, of a vectorAx depending linearly onx through some known operatorA(E; F). WhenE=E
1×E
2,c=(c
1 0), andA is injective and defined through the solution of a partial differential equation, Lions ([6]–[8]) introduced sentinelssF such that (s, Ax)Fis sensitive to x1 E
1 but insensitive to x2 E2. In this paper we prove the existence, in the general case, of (i) a generalized sentinel (s, ) ×E, where F withF dense in 80, such that for anya priori guess x0 ofx, we have s, Ax + (, x0)E=(c, x)E, where x is the least-squares estimate ofx closest tox
0, and (ii) a family of regularized sentinels (s
n
,
n
) F×E which converge to (s, ). Generalized sentinels unify the least-squares approach (by construction !) and the sentinel approach (whenA is injective), and provide a general framework for the construction of sentinels with special sensitivity in the sense of Lions [8]). 相似文献
993.
硫代磷酸酯类化合物的^31P化学位移加和规则 总被引:2,自引:0,他引:2
对近80年种自行合成的硫逐及硫超磷酸酯类化合物进行了^31P NMR谱的测定,提出了一个经验方程、一套化学位移参数的立体电子效应参数,比较准确地计算了它们的^1P化学位移,其计算值与测定值的平均误差为±0.096,标准偏差为±0.13。同时,就取代基的电负性,键角和立体电子效应等对^31P化学位移的影响作了理论上的探讨。 相似文献
994.
Three-dimensional quantum mechanical calculations for vibrational predissociation of He12(B) van der Waals molecules are presented using the time-dependent wave packet technique within the golden rule approximation.
The total and partial decay widths, lifetimes, rates and their dependence on initial vibrational states were obtained for
HeI2 at low initial vibrational excited levels. Our calculations show that the calculated total decay widths, lifetimes and rates
agree well with those extrapolated from experimental data available. The predicted total decay widths as a function of initial
vibrational states exhibit highly nonlinear behavior. The very short propagation time (less than 1 ps) required in the golden
rule wave packet calculation is determined by the duration time of the final state interaction between the fragments on the
vibrationally deexcited adiabatic potential surface. The final state interaction between the fragments is shown to play an
important role in determining the final rotational distribution. This interpretation clearly explains the dynamical effect
that the final rotational distribution shifts to the lower rotational energy levels as the initial vibrational quantum numberu increases. 相似文献
995.
Aliaksei A. Strechan Gennady J. Kabo Yauheni U. Paulechka 《Fluid Phase Equilibria》2006,250(1-2):125-130
Correlation relations based on Stefan's rule, which defined dependence between the enthalpy of vaporization, the surface tension, the molar volume and the molar mass of a substance, were obtained. For development of the correlation equations two computational procedures were used: a method of the least squares and a method of artificial neural networks. The method of artificial neural networks was shown to give somewhat better results than the linear least-squares procedure. The average deviation of the calculated values from the experimental ones did not exceed 6% for training set of substances and 10% for control set (the method of the least squares). For the method of artificial neural networks it is 3% and 8%, respectively. 相似文献
996.
997.
998.
Gerold Alsmeyer 《Mathematical Methods of Operations Research》1986,30(3):A111-A134
Let
1, 2, ... be a sequence of i.i.d. random variables with positive mean
and finite variance
and letr(b), b0, be real numbers tending to 0 asb . Definings
n=1+...+n andS
n=Sn(b)=sn+r(b)n, the stopping time =(b)=inf {n>/1:Sn >b} whereb=b(b) , will be considered with special regard to the excess over the boundaryR
b=s+r(b)–b. It turns out that the limiting distribution ofR
b is the same as in the caser(b)0 for allb. Proving this, Blackwell's renewal theorem and its integral version have to be established first in the above stated situation. Finally, an expansion ofE to vanishing terms asb will be provided and applied to some examples arising in economics.
Zusammenfassung Seien 1, 2, ... unabhängige identisch verteilte Zufallsgrößen mit positivem Erwartungswert und endlicher Varianz sowier(b), b0, reelle Zahlen mitr(b)0 für b. Sei ferners 1, s2, ... der zugehörige Summenprozeß,S n= Sn(b)=sn+r(b)n fürn1 und =(b)=inf {n1: Sn>b, wobeib=b(b) fürb . Es wird gezeigt, daß die asymptotische Verteilung des ExzessesR b=s +r(b) –b mit der im Fallr(·)0 übereinstimmt. Dazu werden sowohl das Blackwellsche Erneuerungstheorem als auch seine Integralversion in der vorher beschriebenen parameterabhängigen Situation geeignet formuliert und bewiesen. Als Folgerung ergibt sich dann eine asymptotische Entwicklung vonE(b) fürb bis zu Termen o(1). Anh- and einiger Beispiele aus dem ökonomischen Bereich wird schließlich noch aufgezeigt, wo Approximationen fürE(b) von Interesse sein können.相似文献
999.
1000.