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31.
Kinetic selection principles have been shown to be useful and physically reasonable in nonlinear hyperbolic problems with
large amplitude phase transitions. We refer to Abeyaratne and Knowles, [A-K], for discussion on the subject. They also have
been used for degenerate nonlinear problems, where the genuine nonlinearity property of Lax is violated. This is the framework
of Liu, [Li], in the kinetic situation of Hayes and Le Floch, [H-L], where their so-called non classical shocks may be seen
as small amplitude phase transitions. Here, we describe the local geometry generated by the generic non genuinely nonlinear
assumption. A geometric kinetic criterion can be used to select indeterminate simple waves and obtain the well-posedness of
the local Riemann problem. A particular case is the entropic kinetic criterion of Hayes and Le Floch.
Sunto Principi di selezione cinetica sono stati mostrati utili e fisicamente ragionevoli in problemi iperbolici con transizioni di fase di grande ampiezza. Ci riferiamo ad Abeyaratne e Knowles, [A-K], per discussioni sull'argomento. Detti principi sono stati usati per problemi nonlineari degeneri, dove la proprietà di genuina nonlinearità di Lax è violata. Questo è la prospettiva di Liu, [Li], nella situazione cinetica di Hayes e Le Floch, [H-L], dove i loro così detti urti non classici possono essere considerati come transizioni di fase di piccola ampiezza. Qui, descriviamo la geometria locale generata dall'ipotesi generica genuinamente nonlineare. Un criterio di geometria cinetica può essere usato per selezionare onde semplici indeterminate ed ottenere la buona posizione per il problema locale di Riemann. Un caso particolare è il criterio di entropia cinetico di Hayes e Le Floc.相似文献
32.
A. P. Prishivalko 《Journal of Applied Spectroscopy》1997,64(1):94-100
A method for finding the optimum sizes of pigment particles, their volume concentration, and the paint coating thickness that
provide the covering power and the required coloristic characteristics of reflected light for the minimum flow rate of pigments
is based on using a four-flow approximation of the solution to the equation of radiation transfer in dispersion media and
is extended to coatings of complex composition. The capabilities of the method are demonstrated by examples of coatings of
mixtures of hematite and rutile particles in a binder with n=1.5 for variations of the modal size and the half-width of the
size distribution of the pigment particles.
B. I. Stepanov Institute of Physics, Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 90–96, January–February, 1997. 相似文献
33.
证券投资组合的风险与收益 总被引:4,自引:1,他引:3
李淑锦 《数学的实践与认识》2002,32(4):602-604
本文利用概率统计原理对证券的投资组合能减轻所遇的风险作了讨论 ,并介绍了如何选择投资组合可使所遇风险达到最小 相似文献
34.
用实验的方法,研究电流并联负反馈对放大器性能的改善,提出电流型、并联型负反馈放大器性能参数的测量方法。 相似文献
35.
Linear and nonlinear optical properties of racemic (±)2-(α-methylbenzylamino)-5-nitropyridine ((±)MBANP) single crystals have been comprehensively investigated and compared with those of the enantiomorph (–)2-(α-methylbenzylamino)-5-nitropyridine ((–)MBANP) crystals. (±)MBANP crystal exhibits very high chemical and physical stability, but relatively small nonlinear optical coefficients (d31 = 6.8 pm/V, d32 = 4.7 pm/V, d33 = 0.84 pm/V). A comparison between the nonlinear optical coefficients of (±)MBANP and (–)MBANP demonstrates the validity of the oriented-gas model in molecular crystals that neglects all the contributions from intermolecular interaction. 相似文献
36.
Hidetoshi Shimodaira 《Annals of the Institute of Statistical Mathematics》1997,49(3):395-410
The asymptotic error probability of Linhart's model selection test isevaluated, and compared with the nominal significance level. We examine thecase where the expected discrepancies of the candidate models from the truemodel are asymptotically equal. The local alternatives method is employed inthe limiting operation of the asymptotic evaluation. Although the errorprobability under the null hypothesis is actually shown to be equal to orless than the level for most situations, intolerable violations of the errorcontrol are observed for nested models: It is often erroneously concludedthat the smaller model is significantly better than the larger model. Toprevent this violation, a modification of Linhart's test statistic isproposed. The effectiveness of the proposed test is confirmed throughtheoretical analysis and numerical simulations. 相似文献
37.
38.
39.
D.L. Skuratov Yu.L. Ratis I.A. Selezneva J. Pérez P. Fernández de Córdoba J.F. Urchueguía 《Applied Mathematical Modelling》2007
This paper deals with modelling the workpiece temperature field produced during the grinding process. The proposed model is given in terms of a two-dimensional boundary-value problem where the interdependence among the grinding wheel, the workpiece and the coolant is described by two variable functions in the boundary condition. An explicit integral form solution is constructed using the Laplace and Fourier transforms and the Green’s function method. 相似文献
40.
一个改进的Hardy-Hilbert不等式 总被引:1,自引:1,他引:0
通过建立权系数的不等式,得到一个改进的Hardy-Hilbert不等式. 相似文献