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181.
182.
N. S. Papageorgiou 《Journal of Optimization Theory and Applications》1991,68(2):305-320
In this paper, we consider a sequence of abstract optimal control problems by allowing the cost integrand, the partial differential operator, and the control constraint set all to vary simultaneously. Using the notions of -convergence of functions,G-convergence of operators, and Kuratowski-Mosco convergence of sets, we show that the values of the approximating problems converge to that of the limit problem. Also we show that a convergent sequence of optimal pairs for the approximating problems has a limit which is optimal for the limit problem. A concrete example of parabolic optimal control problems is worked out in detail.This research was supported by NSF Grant No. DMS-88-02688. 相似文献
183.
Ward Whitt 《Queueing Systems》1991,9(3):235-268
A fundamental principle of queueing theory isL=W (Little's law), which states that the time-average or expected time-stationary number of customers in a system is equal to the product of the arrival rate and the customer-average or expected customer-stationary time each customer spends in the system. This principle is now well known and frequently applied. However, in recent years there have been extensions, such as H=G and the continuous, distributional, ordinal and central-limit-theorem versions, which show that theL=W relation, when viewed properly, has much more power than was previously realized. Moreover, connections have been established between H=G and other fundamental relations, such as the rate conservation law and PASTA (Poisson arrivals see time averages), which show that there is a much greater unity in the overall theory than was previously realized. This paper provides a review.This paper is dedicated to the memory of our colleague Professor Peter Franken (1937–1989), who contributed greatly to the subject of this paper and to queueing theory more generally. 相似文献
184.
The rate-of-convergence problem in the central limit theorem is considered for -stable distributions on the noncommutative group of motions in d. The method used here is based on the theory of probability metrics. 相似文献
185.
H. Faissner P. Göttlicher H. Matela D. Samm 《Zeitschrift für Physik A Hadrons and Nuclei》1992,341(3):359-364
A search for light penetrating scalar and pseudoscalar bosons has been performed at the Jülich nuclear-reactor FRJ-1 (Merlin). In nuclear deexcitation processes pseudoscalar particles should be emitted in magnetic transitions and scalar particles in electric transitions. The experiment relies on the detection of the interaction products from the conversion of bosons in the field of an electron or a nucleus with a rotatable multi-scintillator system. The geometrical arrangement of the scintillators allows to distinguish between scalar and pseudoscalar particles via the different angular distributions of the final state photons. We obtain as upper limits for the product of production ratio and interaction cross sectionW for pseudoscalar particles W}<6.9>6.9>–40 cm2, and for scalar particles W}<1.3>1.3>–39 cm2 with 90% confidence.We gratefully acknowledge the support of this experiment by the KFA Jülich and we are very grateful for most valuable discussions with H. Bechteler, H.R. Koch, O.W.B. Schult, H. Seyfarth and A. Zehnder. We would like to express our thanks to the personnel of the reactor Merlin. We also wish to acknowledge the excellent work of the technical staff of our institute in particular to E. Hermens and R. Pahlke. Thanks to H. Geller and C. Latsch who assisted with the runs. 相似文献
186.
K. -H. Speidel J. Cub U. Reuter F. Passek H. -J. Wollersheim N. Martin P. Egelhof H. Emling W. Henning R. S. Simon R. Schmidt H. -J. Simonis N. Gollwitzer 《Zeitschrift für Physik A Hadrons and Nuclei》1991,339(2):265-268
It is shown that transient magnetic fields in Gd-host for20Ne ions at a mean velocity of 12.5v0(v0=c/137), considerably beyond the Bohr velocity of 1s electrons of Ne ions (v1s=10v0), are dominated by the Fermi contact field of these electrons. The first excited 2+-state of2Ne was used as probe. The derived value for the mean degree of polarization p1s=0.32(13), is surprisingly large, though still consistent with values obtained at lower velocities. Present calculations of spin exchange cross sections severely underestimate the observed polarization at this high velocity.The authors are grateful to the operating staff of the UNILAC for providing excellent beam conditions. They also thank Dr. P. Maier-Komor for preparing the delicate targets. Support by the BMFT is acknowledged. 相似文献
187.
Günter M. Ziegler 《Journal of Algebraic Combinatorics》1992,1(3):283-300
The broken-circuit complex is fundamental to the shellability and homology of matroids, geometric lattices, and linear hyperplane arrangements. This paper introduces and studies the -system of a matroid, nbc(M), whose cardinality is Crapo's -invariant. In studying the shellability and homology of base-pointed matroids, geometric semilattices, and afflne hyperplane arrangements, it is found that the -system acts as the afflne counterpart to the broken-circuit complex. In particular, it is shown that the -system indexes the homology facets for the lexicographic shelling of the reduced broken-circuit complex
, and the basic cycles are explicitly constructed. Similarly, an EL-shelling for the geometric semilattice associated with M is produced,_and it is shown that the -system labels its decreasing chains.Basic cycles can be carried over from
The intersection poset of any (real or complex) afflnehyperplane arrangement is a geometric semilattice. Thus the construction yields a set of basic cycles, indexed by nbc(M), for the union of such an arrangement. 相似文献
188.
A seven-step synthesis ofS-(+)-hydroprene (S-1) in 20 % overall yield starting fromS-(+)-3,7-dimethyl-1,6-octadiene (2) of 55+-10 % optical purity is described. The introduction of an optical enhancement step in the synthetic sequence at the stage ofS-(–)-3,7-dimethyl-1-octanol (9) raises the optical purity ofS-1 from 50 % to 80 %.For part 13, see. ref.1
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 342–348, February, 1993. 相似文献
189.
Bholanath Mandal 《International journal of quantum chemistry》2005,103(2):140-148
A graph theoretical procedure for obtaining eigenvalues of linear chains and cycles having alternant vertex weights (h1, h2, h1, h2, h1, h2, …) and the same edge weight (k) have been developed. The eigenvalues of some complicated graphs, such as graphs of linear polyacenes, methylene‐substituted linear polyacenes and cylindrical polyacene strips, stack graphs, and reciprocal graphs have been shown to be generated in closed analytical forms by this procedure. Many such graphs represent chemically important molecules or radicals. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005 相似文献
190.
Ab initio molecular orbital calculations employing a 4-31G basis set have been used to study the minimum energy paths for the formation of HCO+, COH+, and HCOH2+ from CO by protonation. The protonation of N2 to give NNH+ and HNNH2+ and of NO+ to form HNO2+ and NOH2+ have also been investigated. All species formed have linear equilibrium geometries and the minimum energy path for approach of the proton is along the line-of-centers of the heavy atoms. Energy barriers to the formation of the various species are given, where appropriate, and changes in geometry, ordering of molecular orbitals and orbital occupancy are discussed. 相似文献