共查询到20条相似文献,搜索用时 46 毫秒
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D.J Hartfiel 《Journal of Mathematical Analysis and Applications》1985,108(1):230-240
Let Pij and qij be positive numbers for i ≠ j, i, j = 1, …, n, and consider the set of matrix differential equations x′(t) = A(t) x(t) over all A(t), where aij(t) is piecewise continuous, aij(t) = ?∑i ≠ jaij(t), and pij ? aij(t) ? qij all t. A solution x is also to satisfy ∑i = 1nxi(0) = 1. Let Ct denote the set of all solutions, evaluated at t to equations described above. It is shown that , the topological closure of Ct, is a compact convex set for each t. Further, the set valued function , of t is continuous and . 相似文献
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This paper proposes a new approach for the time-dependent analysis of stochastic and non-stationary queueing systems. The analysis of a series of stationary queueing models leads to a new approximation of time-dependent performance measures. 相似文献
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M. Sabatini 《Journal of Differential Equations》2004,196(1):151-168
We study the period function T of a center O of the title's equation. A sufficient condition for the monotonicity of T, or for the isochronicity of O, is given. Such a condition is also necessary, when f and g are odd and analytic. In this case a characterization of isochronous centers is given. Some classes of plane systems equivalent to such equation are considered, including some Kukles’ systems. 相似文献
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Manisha Kulkarni 《Indagationes Mathematicae》2003,14(1):35-44
Let g(y) ? Q[Y] be an irreducible polynomial of degree n ≥ 3. We prove that there are only finitely many rational numbers x, y with bounded denominator and an integer m ≥ 3 satisfying the equation x(x + 1) (x + 2)…(x + (m − 1) ) = g(y). We also obtain certain finiteness results when g(y) is not an irreducible polynomial. 相似文献
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This paper contains a study of matrices satisfying As = At for different positive integers s and t. Representations, similar to Flor's well-known characterization of a nonnegative idempotent matrix, are obtained for nonnegative matrices of this type. 相似文献
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Let GF(q) be the finite field of order q, let Q(x) be an irreducible polynomial in GF(q)(x), and let h(T)(x) be a linear polynomial in GF(q)[x], where T:x→xq. We use properties of the linear operator h(T) to give conditions for Q(h(T)(x)) to have a root of arbitrary degree k over GF(q), and we describe how to count the irreducible factors of Q(h(T)(x)) of degree k over GF(q). In addition we compare our results with those Ore which count the number of irreducible factors belonging to a linear polynomial having index k. 相似文献
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We consider the periodic boundary value problem of ordinary differential systems with p(t)-Laplacian of the form
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Tetsutaro Shibata 《Journal of Mathematical Analysis and Applications》2002,267(2):576-598
We consider the nonlinear eigenvalue problem on an interval−u″(t)+g(u(t))=λsinu(t),u(t)>0,t∈I:=(−T,T),u(±T)=0,where λ > 0 is a parameter and T > 0 is a constant. It is known that if λ ? 1, then the corresponding solution has boundary layers. In this paper, we characterize λ by the boundary layers of the solution when λ ? 1 from a variational point of view. To this end, we parameterize a solution pair (λ, u) by a new parameter 0 < ?< T, which characterizes the boundary layers of the solution, and establish precise asymptotic formulas for λ(?) with exact second term as ? → 0. It turns out that the second term is a constant which is explicitly determined by the nonlinearity g. 相似文献