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In classical studies of loss systems with restricted availability, the utilization was suggested of a probabilistic loss function, defining the conditional probability of an incoming call being rejected, as a function of the number of occupations in the destination group of servers. This paper gives an exact analysis of stochastic processes of practical relevance, associated with a system with MMPP (Markov Modulated Poisson Process) input, finite queueing capacity and a general loss function, assuming exponential service times. In addition to the process defining the state of the system at any instant, the analysis of the overflow point process (associated with the rejected arriving customers), the accepted point process (associated with the accepted arriving customers), and of the departure process will be presented. Together with the exact analysis of this system, based on the matrix analytical methodology of Neuts, (1981), we will derive expressions for calculating some key-parameters of pertinent associated processes, which may also be used for their approximate modelling. Also, examples of applications and of blocking probability calculations in specific models of this class will be presented. 相似文献
164.
管永精 M. de Cesare F. Terrasi F. Quinto C. Sabbarese N. de Cesare A. D'Onofrio 王慧娟 《中国物理 C》2010,34(11):1729-1732
In order to measure the isotopic ratio of actinides,the upgrade of the accelerator mass spectrometry system at the Center for Isotopic Research on Cultural and Environmental heritage at the Second University of Naples,Italy,was performed.The beam emittance of 238U and the isotopic abundance sensitivity of 236U were measured on the present beam line.Utilizing a 16-strip silicon detector,the sensitivity of 236U/238U≈ 1×10-11 was obtained. 相似文献
165.
C. Conti C. Colombo M. Matteini M. Realini G. Zerbi 《Journal of Raman spectroscopy : JRS》2010,41(10):1254-1260
Nowadays, in order to preserve the surfaces of works of art, several organic and inorganic substances are used. To evaluate the penetration depth and the distribution of these substances inside the materials, it is essential to define the effectiveness of a conservative treatment. Owing to the ambiguous results obtained with the current analytical techniques, the achievement of this aim is critical. This study shows how micro‐Raman mapping on polished cross section is an effective tool capable of investigating the inner portions of the materials. A set of painted plasters has been treated with ammonium oxalate solutions, an inorganic substance widely used for conservation works of carbonatic materials. The micro‐Raman mapping of the lines of the newly formed calcium oxalate allowed correlation of the penetration depth and the distribution of the product inside the specimens with different conditions of treatment. Moreover, a good agreement between micro‐Raman spectroscopy and microscopic techniques has been obtained. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
166.
Optimization Letters - We present an alternating forward–backward splitting method for solving linearly constrained structured optimization problems. The algorithm takes advantage of the... 相似文献
167.
Rinaldo M. Colombo Francesca Marcellini 《Journal of Mathematical Analysis and Applications》2010,361(2):440-456
Consider the p-system describing the subsonic flow of a fluid in a pipe with section a=a(x). We prove that the resulting Cauchy problem generates a Lipschitz semigroup, provided the total variation of the initial datum and the oscillation of a are small. An explicit estimate on the bound of the total variation of a is provided, showing that at lower fluid speeds, higher total variations of a are acceptable. An example shows that the bound on TV(a) is mandatory, for otherwise the total variation of the solution may grow arbitrarily. 相似文献
168.
M.?T.?MercaldoEmail author I.?Rabuffo L.?De?Cesare A.?Caramico D’Auria 《The European Physical Journal B - Condensed Matter and Complex Systems》2013,86(8):340
The effects of single-ion anisotropy on quantum criticality in a d-dimensional spin-S planar ferromagnet is explored by means of the two-time Green’s function method. We work at the Tyablikov decoupling level for exchange interactions and the Anderson-Callen decoupling level for single-ion anisotropy. In our analysis a longitudinal external magnetic field is used as the non-thermal control parameter and the phase diagram and the quantum critical properties are established for suitable values of the single-ion anisotropy parameter D. We find that the single-ion anisotropy has sensible effects on the structure of the phase diagram close to the quantum critical point. However, for values of the uniaxial crystal-field parameter below a positive threshold, the conventional magnetic-field-induced quantum critical scenario remains unchanged. 相似文献
169.
Cesare Parenti 《偏微分方程通讯》2013,38(8):837-888
We show that for a class of hyperbolic second order operators with double characteristics the Ivrii–Petkov condition is also sufficient for the well-posedness of the Cauchy problem in C ∞. 相似文献
170.
S. Giordano P. L. Palla L. Colombo 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,66(1):29-35
We prove a generic theorem stating the equivalence
between a graded dielectric ellipsoid (with gradation along a family of
internal confocal ellipsoids) and an anisotropic homogeneous ellipsoid. We then describe a procedure to obtain the three principal
permittivities of the effective ellipsoid for any given dielectric gradation profile. Finally, we apply a multiscale approach
to homogenize dispersions of ellipsoidal graded particles. 相似文献