共查询到19条相似文献,搜索用时 15 毫秒
1.
2.
J. Plávka 《Mathematical Methods of Operations Research》1992,36(5):417-422
Let twon×n matrices be given, namely a real matrixA=(aij) and a (0, 1)-matrixT=(tij). For a cyclic permutation=(i
1,i
2,...,i
k) of a subset of N={1, 2, ..., n} we define A;T(), the cost-to-time ratio weight of, as
. This paper presents an O(n3) algorithm for finding (A;T)=max A;T(), the maximum cost-to-time ratio weight of the matricesA andT. Moreover a generalised eigenproblem is proposed. 相似文献
3.
N. Temirgaliev Sh. K. Abikenova A. Zh. Zhubanysheva G. E. Taugynbaeva 《Russian Mathematics (Iz VUZ)》2013,57(8):75-80
We study three concretizations of the notion of computer (computing) diameter, namely, the discretization of solutions to the Klein-Gordon equation, numerical differentiation, and function recovery. 相似文献
4.
D. Juriev 《Acta Appl Math》1998,50(1-2):191-196
This paper is a revised and expanded version of two notes devoted to nonassociative structures in quantum projective field theory. 相似文献
5.
Fadoua Hamzaoui-Azaza Mounira Zammouri Meriem Ameur Mohamedou Baba Sy Moncef Gueddari Rachida Bouhlila 《Natural Resource Modeling》2020,33(4):e12282
The study of water quality and the quantification of reserves and their variations according to natural and anthropogenic forcing is necessary to establish an adequate management plan for groundwater resources. For this purpose, a modeling approach is a useful tool that allows, after calibration phase and verification of simulation, and under different scenarios of forcing and operational changes, to estimate and control the groundwater quantity and quality. The main objective of this study is to collect all available data in a model that simulates the Jeffara of Medenine coastal aquifer system functioning. To achieve this goal, a conceptual model was constructed based on previous studies and hydrogeological investigations. The regional groundwater numerical flow model for the Jeffara aquifer was developed using MODFLOW working under steady-state and transient conditions. Groundwater elevations measured from the piezometric wells distributed throughout the study area in 1973 were selected as the target water levels for steady state (head) model calibration. A transient simulation was undertaken for the 42 years from 1973 to 2015. The historical transient model calibration was satisfactory, consistent with the continuous piezometric decline in response to the increase in groundwater abstraction. The developed numerical model was used to study the system's behavior over the next 35 years under various constraints. Two scenarios for potential groundwater extraction for the period 2015–2050 are presented. The predictive simulations show the effect of the increase of the exploitation on the piezometric levels. To study the phenomenon of salinization, which is one of the most severe and widespread groundwater contamination problems, especially in coastal regions, a solute transport model has been constructed by using MT3DMS software coupled with the groundwater flow model. The best calibration results are obtained when the connection with the overlying superficial aquifer is considered suggesting that groundwater contamination originates from this aquifer. Recommendations for water resource managers
- The results of this study show that Groundwater resources of Jeffara of Medenine coastal aquifer in Tunisia are under immense pressure from multiple stresses.
- The water resources manager must consider the impact of economic and demographic development in groundwater management to avoid the intrusion of saline water.
- The results obtained presented some reference information that can serve as a basis for water resources planning.
- The model runs to provide information that managers can use to regulate and adequately control the Jeffara of Medenine water resources.
6.
7.
8.
2‐(v,k,1) Designs Admitting a Primitive Rank 3 Automorphism Group of Affine Type: The Extraspecial and the Exceptional Classes
下载免费PDF全文
![点击此处可从《组合设计杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Alessandro Montinaro 《组合设计杂志》2015,23(11):481-498
2‐(v,k,1) designs admitting a primitive rank 3 automorphism group , where G0 belongs to the Extraspecial Class, or to the Exceptional Class of Liebeck's Theorem in [23], are classified. 相似文献
9.
H. Essaouini L. El Bakkali P. Capodanno 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2011,62(5):849-868
The authors study the small oscillations of a pendulum containing an almost homogeneous, incompressible, inviscid liquid (i.e. a liquid whose density in equilibrium is practically a linear function of the height, which differs very little from a constant) and a moving gas. Using functional analysis, they prove that the spectrum is comprised of a countable set of real eigenvalues and an essential spectrum, which fills an interval, and they give an existence and uniqueness theorem for the solution of the evolution problem. 相似文献
10.
B. V. Pal’tsev I. I. Chechel’ 《Computational Mathematics and Mathematical Physics》2006,46(5):820-847
The convergence rate of a fast-converging second-order accurate iterative method with splitting of boundary conditions constructed by the authors for solving an axisymmetric Dirichlet boundary value problem for the Stokes system in a spherical gap is studied numerically. For R/r exceeding about 30, where r and R are the radii of the inner and outer boundary spheres, it is established that the convergence rate of the method is lower (and considerably lower for large R/r) than the convergence rate of its differential version. For this reason, a really simpler, more slowly converging modification of the original method is constructed on the differential level and a finite-element implementation of this modification is built. Numerical experiments have revealed that this modification has the same convergence rate as its differential counterpart for R/r of up to 5 × 103. When the multigrid method is used to solve the split and auxiliary boundary value problems arising at iterations, the modification is more efficient than the original method starting from R/r ~ 30 and is considerably more efficient for large values of R/r. It is also established that the convergence rates of both methods depend little on the stretching coefficient η of circularly rectangular mesh cells in a range of η that is well sufficient for effective use of the multigrid method for arbitrary values of R/r smaller than ~ 5 × 103. 相似文献
11.
《Optimization》2012,61(4):635-639
First it is shown that the implementation of the algorithm proposed in the considered paper may cause some problems if no further specification is made as to one of its steps. Secondly, such a specification is suggested. 相似文献
12.
Jan W. Owsiński 《European Journal of Operational Research》1983,14(4):397-398
13.
S. De Winter 《Journal of Algebraic Combinatorics》2006,24(3):285-297
Let be a proper partial geometry pg(s,t,2), and let G be an abelian group of automorphisms of acting regularly on the points of . Then either t≡2±od
s+1 or is a pg(5,5,2) isomorphic to the partial geometry of van Lint and Schrijver (Combinatorica 1 (1981), 63–73). This result is a new step towards the classification of partial geometries with an abelian Singer group and further provides an interesting characterization of the geometry of van Lint and Schrijver.The author is Postdoctoral Fellow of the Fund for Scientific Research Flanders (FWO-Vlaanderen). 相似文献
14.
15.
16.
A consecutive(r, s)-out-of-(m, n):F lattice system which is defined as a two-dimensional version of a consecutive k-out-of-n:F system is used as a reliability evaluation model for a sensor system, an X-ray diagnostic system, a pattern search system, etc. This system consists of m × n components arranged like an (m, n) matrix and fails iff the system has an (r, s) submatrix that contains all failed components. In this paper we deal a combined model of a k-out-of-mn:F and a consecutive (r, s)-out-of-(m, n):F lattice system. Namely, the system has one more condition of system down, that is the total number of failed components, in addition to that of a consecutive (r, s)-out-of-(m, n):F lattice system. We present a method to obtain reliability of the system. The proposed method obtains the reliability by using a combinatorial equation that does not depend on the system size. Some numerical examples are presented to show the relationship between component reliability and system reliability. 相似文献
17.
《European Journal of Operational Research》1986,23(1):132-133
18.
S. É. Derkachev 《Theoretical and Mathematical Physics》2011,169(2):1539-1550
We show a connection between the R-matrix factorization, the Baxter Q-operator, and separation of variables in the example
of an integrable spin chain with the SL(2, ℂ) symmetry group. 相似文献
19.
Rémi Arcangéli María Cruz López de Silanes Juan José Torrens 《Numerische Mathematik》2007,107(2):181-211
Given a function f on a bounded open subset Ω of with a Lipschitz-continuous boundary, we obtain a Sobolev bound involving the values of f at finitely many points of . This result improves previous ones due to Narcowich et al. (Math Comp 74, 743–763, 2005), and Wendland and Rieger (Numer
Math 101, 643–662, 2005). We then apply the Sobolev bound to derive error estimates for interpolating and smoothing (m, s)-splines. In the case of smoothing, noisy data as well as exact data are considered. 相似文献