共查询到10条相似文献,搜索用时 78 毫秒
1.
D. Novakovich 《Cybernetics and Systems Analysis》2000,36(2):244-247
The computation time for counting “good” permutations rapidly grows as the length of permutations increases. The paper presents
algorithms for enumeration of “good” permutations. Algorithms reducing twice the number of “good” permutations that should
be counted are considered along with the algorithm employing the concept of weight of a “good” permutation.
Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 106–110, March–April, 2000. 相似文献
2.
L. M. Koganov 《Cybernetics and Systems Analysis》2007,43(4):499-506
It is shown that a formula that was independently obtained earlier for the number of cyclically irreducible words of length
n in a symmetric alphabet of a finitely generated free group of rank k and the Whitney formula for a chromatic polynomial
of a simple nonself-intersecting cycle of length n with a variable λ are mutually deducible from one another when λ = 2k.
The necessary bijections differ for even and odd values of n.
To the memory of William T. Tutte (05.14.1917–05.02.2002)
__________
Translated from Kibernetika i Sistemnyi Analiz, No. 4, pp. 39–48, July–August 2007. 相似文献
3.
V. M. Kravtsov 《Cybernetics and Systems Analysis》2007,43(1):25-33
It is proved that, for any r ∈ { 2n, 2n + 1,…, 3n−2} and only for such r, the polytope of a three-index axial assignment problem
of order n, n ≥ 2, contains completely r-noninteger vertices (r-CNVs), i.e., vertices such that all their positive components
are fractional and their number equals r. For each r ∈ {2n, 2n + 1,…, 3n −2}, all the types of r-CNVs are characterized and
the combinatorial properties of completely r-noninteger vertices of the polytope are studied.
__________
Translated from Kibernetika i Sistemnyi Analiz, No. 1, pp. 33–44, January–February 2007. 相似文献
4.
A constructive image of the solution to a homogeneous Cauchy problem in a Banach space with a densely specified linear closed
logarithmically-sector operator is investigated. The uniform accuracy of estimation of an approximate solution in t ≥ 0 is
proved.
__________
Translated from Kibernetika i Sistemnyi Analiz, No. 3, pp. 145–152, May–June 2005. 相似文献
5.
The effects of planar inlet plenum geometry on the developing flow fields in two rectangular microchannels of reciprocal aspect
ratios (H/W ∼2.75 and ∼0.40) were investigated for Re
D
= 1–100 using micro particle image velocimetry (μPIV). These two microchannels were made by a precision sawing and silicon
microfabrication techniques. Both the velocity profiles and centerline velocity developments were clearly resolved and extracted
along the axial distance from μPIV results. The entrance lengths were found from the centerline velocities using a decaying
exponential fitting function where the centerline velocity reaches 99% of the fully developed centerline velocity. The proposed
fitting function showed excellent agreement with the experimental results. The planar plenum was shown to cause an upstream
predevelopment resulting in the significant reductions in the entrance lengths. Two entrance length correlations were proposed
in the forms of Atkinson et al.’s (AIChE J 15:548–553, 1969) and Chen’s (J Fluids Eng 95:153–158, 1973) correlations. The proposed entrance length correlations showed that acquired constant portion and slope of the entrance
lengths showed 23–27 and 70–81% reductions for H/W = 2.75 while the entrance length correlation for H/W = 0.40 showed 69–73% increase and 41–63% decrease in the constant portion and slope, respectively. 相似文献
6.
Particular cases of nonlinear systems of delay Volterra integro-differential equations (denoted by DVIDEs) with constant delay
τ > 0, arise in mathematical modelling of ‘predator–prey’ dynamics in Ecology. In this paper, we give an analysis of the global
convergence and local superconvergence properties of piecewise polynomial collocation for systems of this type. Then, from
the perspective of applied mathematics, we consider the Volterra’s integro-differential system of ‘predator–prey’ dynamics
arising in Ecology. We analyze the numerical issues of the introduced collocation method applied to the ‘predator–prey’ system
and confirm that we can achieve the expected theoretical orders of convergence.
相似文献
7.
A multicriterion Boolean problem of lexicographic optimization with partial criteria represented by moduli (absolute values)
of linear functions is considered. Five types of stability of a set of lexicographic optima under “small” variations in the
parameters of a vector criterion are investigated.
__________
Translated from Kibernetika i Sistemnyi Analiz, No. 5, pp. 178–187, September–October 2007. 相似文献
8.
A. G. Sitnik 《Cybernetics and Systems Analysis》2000,36(3):397-404
A direction of improvement of a method for formation of color images on offset plates is proposed. The method and tools developed
for synthesizing color images are experimentally tested.
Translated from Kibernetika i Sistemnyi Analiz, No. 3, pp. 99–109, May–June, 2000. 相似文献
9.
S. D. Pogorilyy Yu. V. Boyko A. D. Gusarov S. I. Lozytskyi 《Cybernetics and Systems Analysis》2009,45(2):291-296
The body of mathematics of modified systems of algorithmic algebras (SAA-M) is used to formalize the Edmonds–Karp algorithm
of finding the maximum flow in a network. With allowance made for the distributed system features that are usually used for
solving complicated problems, optimization criteria are formulated and used to obtain parallel SAA-M-schemes.
Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 146–152, March–April 2009. 相似文献
10.
V. G. Tul’chinskii I. N. Pshonkovskaya S. V. Zaytseva 《Cybernetics and Systems Analysis》1999,35(4):543-552
The functioning of Kanerva’s Sparse Distributed Memory is examined under conditions of changes in data that are to be written
at an address. To improve the efficiency of retraining, a modification of the Kanerva writing procedure is proposed.
Translated from Kibernetika i Sistemnyi Analiz, No. 4, pp. 40–49, July–August, 1999. 相似文献