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1.
In this paper, we propose approximations to compute the steady-state performance measures of the M/GI/N+GI queue receiving Poisson arrivals with N identical servers, and general service and abandonment-time distributions. The approximations are based on scaling a single
server M/GI/1+GI queue. For problems involving deterministic and exponential abandon times distributions, we suggest a practical way to compute
the waiting time distributions and their moments using the Laplace transform of the workload density function. Our first contribution
is numerically computing the workload density function in the M/GI/1+GI queue when the abandon times follow general distributions different from the deterministic and exponential distributions.
Then we compute the waiting time distributions and their moments. Next, we scale-up the M/GI/1+GI queue giving rise to our approximations to capture the behavior of the multi-server system. We conduct extensive numerical
experiments to test the speed and performance of the approximations, which prove the accuracy of their predictions.
相似文献
2.
G. Falin 《Queueing Systems》2008,58(1):65-76
We consider the M/M/∞ queueing system with arrival and service rate depending on the state of an auxiliary semi-Markov process (which can be
viewed as an external environment) and find the mean number of customers in the system in steady state. In a particular case
when the external environment can be only in two states we find the distribution of the number of customers in the system.
相似文献
3.
4.
V. K. Maslyuchenko V. V. Mykhailyuk O. I. Filipchuk 《Ukrainian Mathematical Journal》2008,60(11):1803-1812
We introduce the notion of categorical cliquish mapping and show that, for each K
h
C-mapping f: X × Y → Z, where X is a topological space, Y is a space with the first axiom of countability, and Z is a Moore space, with categorical-cliquish horizontal y-sections f
y
, the sets C
y
(f) are residual G
δ-type sets in X for every y ∈ Y.
Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 60, No. 11, pp. 1539–1547, November, 2008. 相似文献
5.
Summary In [6] we introduced and investigated the notions of fI -sets and fI -continuous functions in ideal topological spaces. In this paper, we investigate their further important properties. 相似文献
6.
Guohua Wu 《Archive for Mathematical Logic》2003,42(2):201-204
We give a characterization of strongly compact cardinals in terms of Q
κ
λ. We also prove that weakly normal Q-measures on Q
κ
λ are ⊂κ-normal.
Received: 29 September 2000 / Revised version: March 2002 Published online: 5 November 2002
This project is supported by the New Zealand Marsden Fund. The author wishes to thank the referee for numerous comments and
suggestions which have been incorporated into this version of the paper. 相似文献
7.
Thomas Vougiouklis 《数学学报(英文版)》2008,24(7):1067-1078
The hyperoperations, called theta-operations (δ), are motivated from the usual property, which the derivative has on the derivation of a product of functions. Using any map on a set, one can define δ-operations. In this paper, we continue our study on the δ-operations on groupoids, rings, fields and vector spaces or on the corresponding hyperstructures. Using δ-operations one obtains, mainly, Hwstructures, which form the largest class of the hyperstructures. For representation theory of hyperstructures, by hypermatrices, one needs special Hv-rings or Hy-fields, so these hyperstructures can be used. Moreover, we study the relation of these δ-structures with other classes of hyperstructures, especially with the Hv-structures. 相似文献
8.
Tunay Bilgin 《Czechoslovak Mathematical Journal》2005,55(3):691-697
The definition of lacunary strongly convergence is extended to the definition of lacunary strong (A
σ
, p)-convergence with respect to invariant mean when A is an infinite matrix and p = (p
i
) is a strictly positive sequence. We study some properties and inclusion relations. 相似文献
9.
Jinjin Li 《Czechoslovak Mathematical Journal》2005,55(4):941-945
In this note we study the relation between k
R
-spaces and k-spaces and prove that a k
R
-space with a σ-hereditarily closure-preserving k-network consisting of compact subsets is a k-space, and that a k
R
-space with a point-countable k-network consisting of compact subsets need not be a k-space.
This work was supported by the NSF of China (10271056). 相似文献
10.
Using elementary graded automorphisms of polytopal algebras (essentially the coordinate rings of projective toric varieties)
polyhedral versions of the group of elementary matrices and the Steinberg and Milnor groups are defined. They coincide with
the usual K-theoretic groups in the special case when the polytope is a unit simplex and can be thought of as compact/polytopal substitutes
for the tame automorphism groups of polynomial algebras. Relative to the classical case, many new aspects have to be taken
into account. We describe these groups explicitly when the underlying polytope is 2-dimensional. Already this low-dimensional
case provides interesting classes of groups.
Received: 13 December 2001 / Revised version: 24 June 2002
The second author was supported by the Deutsche Forschungsgemeinschaft, INTAS grant 99-00817 and TMR grant ERB FMRX CT-97-0107
Mathematics Subject Classification (2000): 14L27, 14M25, 19C09, 52B20 相似文献
11.
J.C. FERRANDO S. MOLL 《数学学报(英文版)》2007,23(9):1593-1600
In this paper, we show, among other results, that if X is a [separable] locally compact space X [satisfying the first countability axiom] then the space Cc (X) has countable tightness [if and only if it has bounding tightness] if and only if it is Frechet-Urysohn, if and only if Cc (X) contains a dense (LM) subspace and if and only if X is a-compact. 相似文献
12.
G. I. Falin 《Queueing Systems》2008,58(3):155-160
Sherman and Kharoufeh (Oper. Res. Lett. 34:697–705, [2006]) considered an M/M/1 type queueing system with unreliable server and retrials. In this model it is assumed that if the server fails during service
of a customer, the customer leaves the server, joins a retrial group and in random intervals repeats attempts to get service.
We suggest an alternative method for analysis of the Markov process, which describes the functioning of the system, and find
the joint distribution of the server state, the number of customers in the queue and the number of customers in the retrial
group in steady state.
相似文献
13.
Yaroslav Kopylov 《Archiv der Mathematik》2007,89(1):87-96
We consider some problems concerning the L
p,q
-cohomology of Riemannian manifolds. In the first part, we study the question of the normal solvability of the operator of
exterior derivation on a surface of revolution M considered as an unbounded linear operator acting from Lpk (M) into Lk+1q (M). In the second part, we prove that the first L
p,q-cohomology of the general Heisenberg group is nontrivial, provided that p < q.
Received: 17 January 2006
Supported by INTAS (Grant 03–51–3251) and the State Maintenance Program for the Leading Scientific Schools of the Russian
Federation (Grants NSh 311.2003.1, NSh 8526.2006.1). 相似文献
14.
15.
Florentina Chirte§ 《Central European Journal of Mathematics》2005,3(1):105-124
The aim of this paper is to define the localization LM
n
-algebra of an LM
n
—algebra L with respect to a topology F on L; in Section 5 we prove that the maximal LM
n
-algebra of fractions (defined in [3]) and the LM
n
-algebra of fractions relative to an Λ—closed system (defined in Section 2) are LM
n
-algebras of localization. 相似文献
16.
We derive fast recursions to compute the probability that k or more consecutive customer losses take place during a busy period of a queue, the so called k-CCL probability, for regular and oscillating M
X
/G/1/n systems. 相似文献
17.
ChangJian Zhao 《中国科学A辑(英文版)》2008,51(12):2172-2188
In this paper the author first introduce a new concept of L
p
-dual mixed volumes of star bodies which extends the classical dual mixed volumes. Moreover, we extend the notions of L
p
intersection body to L
p
-mixed intersection body. Inequalities for L
p
-dual mixed volumes of L
p
-mixed intersection bodies are established and the results established here provide new estimates for these type of inequalities.
This work was supported by the Natural Science Foundation of Zhejiang Province of China (Grant No. Y605065) and the Foundation
of the Education Department of Zhejiang Province of China (Grant No. 20050392) 相似文献
18.
Wu Yang YU Dong Hua WU Gang Song LENG 《数学学报(英文版)》2007,23(11):1937-1948
The purpose of this paper is to generalize the notion of intersection bodies to that of quasi Lp-intersection bodies. The Lp-analogs of the Busemann intersection inequality and the Brunn- Minkowski inequality for the quasi Lp-intersection bodies are obtained. The Aleksandrov Fenchel inequality for the mixed quasi Lp-intersection bodies is also established. 相似文献
19.
Jeffrey D. Streets 《Journal of Geometric Analysis》2008,18(1):249-271
We study the gradient flow of the Riemannian functional ℱ(g):=∫
M
|Rm|2. This flow corresponds to a fourth-order degenerate parabolic equation for a Riemannian metric. We prove that the degeneracies
may be accounted for entirely by diffeomorphism flow, and hence we show short-time existence using the DeTurck method. We
prove L
2 derivative estimates of Bernstein-Bando-Shi type and use these to give a basic obstruction to long time existence and prove
a compactness theorem.
相似文献
20.
In this paper, the necessary and sufficient conditions for the existence of a (gv, g, 3, λ)-difference family in Z
gv
are established. As a consequence, the existence spectrum of a cyclic (3, λ)-GDD of type g
v
without short orbits is determined.
This work was supported by National Natural Science Foundation of China (Grants Nos. 10771013, 10831002) 相似文献