共查询到20条相似文献,搜索用时 31 毫秒
1.
彭志刚 《数学物理学报(B辑英文版)》1999,19(4):457-462
1Intr0ducti0nLetAden0tethesetofallfunctionsanalyticinA={z:Izl<1}.LetB={W:WEAandIW(z)l51}.Aisalocallyconvexlineaztop0l0gicalspacewithrespecttothetopologyofuniformconvergenceon`c0mpact8ubsetsofA-LetTh(c1,'tc.-1)={p(z):p(z)EA,Rop(z)>0,p(z)=1 clz czzz ' c.-lz"-l 4z" ',wherecl,',cn-1areforedcomplexconstants}.LetTh,.(b,,-..,b,-,)={p(z):P(z)'EAwithReP(z)>Oandp(z)=1 blz ' b.-lz"-l 4z" '-,wherebl,-'-jbu-1areffeedrealconstantsanddkarerealnumbersf0rk=n,n 1,'--}-LetTu(l1,'i'tI.-1)={… 相似文献
2.
Given rational matrix functions ψ1(λ) = Im + C1(λIn1 − A1)−1B1 and ψ2(λ) = Im + C2(λIn2 − A2)−1B2 which are analytic and invertible on the unit circle, we characterize in terms of the operators A1,B1,C1,A2,B2,C2 when there exists a single rational matrix function W(λ) = Im + C(λIn − A)−1B such that WH2m⊥ = ψ 1H2m⊥and WH2m = ψ2H2m. When this is the case, we give explicit formulae for A,B,C in terms of A1,B1,C1,A2,B2,C2. Applications include Wiener-Hopf factorization, J- inner-outer factorization, and coprime factorization. The results on J-inner-outer factorization have application to a model reduction problem for discrete time linear systems. 相似文献
3.
Minimal free resolutions for prime ideals with generic zero (tn3,tn3?n10tn11,tn3?n20tn2, tn31), n1<n2<n3 positive integers, (n1,n2,n3)=1, are determined. 相似文献
4.
《Journal de Mathématiques Pures et Appliquées》1999,78(2):177-202
Given a triple (G, W, γ) of an open bounded set G in the complex plane, a weight function W(z) which is analytic and different from zero in G, and a number γ with 0 ≤ γ ≤ 1, we consider the problem of locally uniform rational approximation of any function ƒ(z), which is analytic in G, by weighted rational functions Wmi+ni(z)Rmi, ni(z)i = 0∞, where Rmi, ni(z) = Pmi(z)/Qni(z) with deg Pmi ≤ mi and deg Qni ≤ ni for all i ≥ 0 and where mi + ni → ∞ as i → ∞ such that lim mi/[mi + ni] = γ. Our main result is a necessary and sufficient condition for such an approximation to be valid. Applications of the result to various classical weights are also included. 相似文献
5.
Let n≥23 be an integer and let D2n be the dihedral group of order 2n. It is proved that, if g1,g2,…,g3n is a sequence of 3n elements in D2n, then there exist 2n distinct indices i1,i2,…,i2n such that gi1gi2?gi2n=1. This result is a sharpening of the famous Erd?s-Ginzburg-Ziv theorem for G=D2n. 相似文献
6.
John E. Olson 《Journal of Number Theory》1977,9(1):63-70
If g1, g2, …, g2n?1 is a sequence of 2n ? 1 elements in an Abelian group G of order n, it is known that there are n distinct indices i1, i2, …, in such that 0 = gi1 + gi2 + ? + gin. In this paper a suitably general condition on the sequence is given which insures that every element g in G has a representation g = gi1 + gi2 + ? + gin as the sum of n terms of the sequence. 相似文献
7.
Zhihe Liang 《Journal of Applied Mathematics and Computing》2007,24(1-2):261-271
The symbol C(m1 n 1m2 n 2...ms n s) denotes a 2-regular graph consisting ofn i cycles of lengthm i , i=1, 2,…,s. In this paper, we give some construction methods of cyclic(K v ,G)-designs, and prove that there exists a cyclic(K v , G)-design whenG=C((4m 1) n 1(4m 2) n 2...(4m s ) n s andv ≡ 1 (mod 2¦G¦). 相似文献
8.
F.K. Hwang 《Discrete Mathematics》1980,32(2):163-165
Let Tn denote a binary tree with n terminal nodes V={υ1,…,υn} and let li denote the path length from the root to υi. Consider a set of nonnegative numbers W={w1,…,wn} and for a permutation π of {1,…,n} to {1,…,n}, associate the weight wi to the node υπ(i). The cost of Tn is defined as C(Tn∣W)=Minπ∑ni=1wilπ(i).A Huffman tree Hn is a binary tree which minimizes C(Tn∣W) over all possible Tn. In this note, we give an explicit expression for C(Hn∣W) when W assumes the form: wi=k for i=1,…,n?m; wi=x for i=n?m+1,…,n. This simplifies and generalizes earlier results in the literature. 相似文献
9.
Letn = (a1.a2 … aN) denote a sequence of integers ai={1.2.…n}. A rise is a part ai.ai+1 with ai <ai+1: a fall is a pair with aiai+1: a level is a pair with ai = ai+1. A maximum is a triple ai-1.aiai+1 with ai-1?ai.ai?ai+1. If ei is the number of aj?n withaj = i, then [e1…en] is called the specification of n. In addition, a conventional rise is counted to the left of a1 and a conventional fall to the right of aN: ifa1?a2, then a1 is counted as a conventional maximum, similarly if aN-1 ? aN thenaN is a conventional maximum. Simon Newcomb's problem is to find the number of sequences n with given specification and r rises; the refined problem of determining the number of sequences of given specification with r rises and s falls has also been solved recently. The present paper is concerned with the problem of finding the number of sequences of given specification with r rises, s falls. λ levels and λ maxima. A generating function for this enumerant is obtained as the quotient of two continuants. In certain special cases this result simplifies considerably. 相似文献
10.
Won Keun Min 《Acta Mathematica Hungarica》2011,132(1-2):107-112
The notions of ??(?? 1,?? 2), ??(?? 1,?? 2) and (??(?? 1,?? 2),??(?? 1,?? 2))-continuity were introduced in [2]. In this paper, the characterization of the continuity is investigated, and we introduce the (??(?? 1,?? 2),??(?? 1,?? 2))-continuity on generalized topological spaces. Finally, we investigate the relations between (??(?? 1,?? 2),??(?? 1,?? 2))-continuity and (??(?? 1,?? 2),??(?? 1,?? 2))-continuity on generalized topological spaces 相似文献
11.
Vladimir I Ovchinnikov 《Comptes Rendus Mathematique》2002,334(10):881-884
We consider linear operators T mapping a couple of weighted Lp spaces {Lp0(U0), Lp1(U1)} into {Lq0(V0),Lq1(V1)} for any 1?p0, p1, q0, q1?∞, and describe the interpolation orbit of any a∈Lp0(U0)+Lp1(U1) that is we describe a space of all {Ta}, where T runs over all linear bounded mappings from {Lp0(U0),Lp1(U1)} into {Lq0(V0),Lq1(V1)}. We show that interpolation orbit is obtained by the Lions–Peetre method of means with functional parameter as well as by the K-method with a weighted Orlicz space as a parameter. To cite this article: V.I. Ovchinnikov, C. R. Acad. Sci. Paris, Ser. I 334 (2002) 881–884. 相似文献
12.
Bohuslav Diviš 《Journal of Number Theory》1977,9(4):426-435
The exact order of the remainder term is determined in the formula for the number of lattice points in the region α1∥u1 + b1∥ + α2∥u2 + b2∥ + … + αr∥ur + br∥ ≤ x in dependence on the arithmetical properties of the coefficients α1, α2,…, αr. 相似文献
13.
We deal with MAXH0-FREE PARTIAL SUBGRAPH. We mainly prove that 3-locally optimum solutions achieve approximation ratio (δ0+1)/(B+2+ν0), where B=maxv∈VdG(v), δ0=minv∈V(H0)dH0(v) and ν0=(|V(H0)|+1)/δ0. Next, we show that this ratio rises up to 3/(B+1) when H0=K3. Finally, we provide hardness results for MAXK3-FREE PARTIAL SUBGRAPH. 相似文献
14.
David S. Herscovici 《Discrete Mathematics》2008,308(24):6501-6512
A pebbling move on a connected graph G consists of removing two pebbles from some vertex and adding one pebble to an adjacent vertex. We define ft(G) as the smallest number such that whenever ft(G) pebbles are on G, we can move t pebbles to any specified, but arbitrary vertex. Graham conjectured that f1(G×H)≤f1(G)f1(H) for any connected G and H. We define the α-pebbling number α(G) and prove that α(Cpj×?×Cp2×Cp1×G)≤α(Cpj)?α(Cp2)α(Cp1)α(G) when none of the cycles is C5, and G satisfies one more criterion. We also apply this result with G=C5×C5 by showing that C5×C5 satisfies Chung’s two-pebbling property, and establishing bounds for ft(C5×C5). 相似文献
15.
The concepts of I-R closed set, A I-R-set, α I M 1-set, α I M 2-set, α I N 1-set, α I N 2-set, α I N 3-set, α I N 4-set and α I N 5-set are introduced via idealization. New decompositions of some weaker forms of continuity are obtained by using these sets. 相似文献
16.
《Statistics & probability letters》1986,4(2):57-59
Let (Y1, Z1),…,(YN, ZN) be i.i.d. pairs of independent random variables such that Yi is exponentially distributed with unknown mean 1/λ and Zi has an unknown distribution function F. Let Xi ≔ min(Yi, Zi). Under certain assumptions on F an estimator TN(X1,…,XN) for 1/λ is constructed which is consistent and asymptotically normal. 相似文献
17.
《Journal of Combinatorial Theory, Series A》1985,40(1):175-178
Suppose x1, x2,…, is a sequence of vectors in Rk, 6Xn6⩽1, where 6(x1,…,xk)6 = maxj|xj|. An algorithm is given for choosing a corresponding sequence ε1, ε2,…, of numbers, εn = ±1, so that 6ε1x1+ … +εnxn6 remains small. 相似文献
18.
A regular graph G = (V, E) is a k-stratified graph if V is partitioned into V1, V2, …, Vk subsets called strata. The stratification splits the degree dv ∀v ϵ V into k-integers dv1, dv2, …, dvk each one corresponding to a stratum. If dv1 = dv2 = … = dvk ∀v ϵ V then G is called regular uniform k-stratified, RUks(n, d) where n is the cardinality of the vertex set in each stratum and d is the degree of every vertex in each stratum. For every k, the class RUks(n, d) has a unique graph generator class RUls(n, d) derived by decomposition of graphs in RUks(n, d). We investigate the minimization of the cardinality of V, the colorability, vertex coloring and the diameter of the graphs in the class. We also deal with complexity questions concerning RUks(n, d). Some well-known computer network models such as barrel shifters and hypercubes are shown to belong in RUks(n, d). 相似文献
19.
Laurie B. Hopkins William T. Trotter Douglas B. West 《Discrete Applied Mathematics》1984,8(2):163-187
The interval number of a graph G, denoted i(G), is the least positive integer t for which G is the intersection graph of a family of sets each of which is the union of at most t closed intervals of the real line . Trotter and Harary showed that the interval number of the complete bipartite graph K(m,n) is . Matthews showed that the interval number of the complete multipartite graph K(n1,n2,…,np) was the same as the interval number of K(n1,n2) when n1 = n2 = ? = np. Trotter and Hopkins showed that i(K(n1,n2,…,np)) ≤ 1 + i(K(n1,n2)) whenever p ≥ 2 and n1≥n2≥ ? ≥np. West showed that for each n ≥ 3, there exists a constant cn so that if p ≥ cn,n1 = n2?n ?1, and n2 = n3 = ? np = n, then i(K(n1,n2,…,np) = 1 + i(K(n1, n2)). In view of these results, it is natural to consider the problem of determining those pairs (n1,n2) with n1 ≥ n2 so that i(K(n2,…,np)) = i(K(n1,n2)) whenever p ≥ 2 and n2 ≥ n3 ≥ ? ≥ np. In this paper, we present constructions utilizing Eulerian circuits in directed graphs to show that the only exceptional pairs are (n2 ? n ? 1, n) for n ≥ 3 and (7,5). 相似文献
20.
LongYun Ding 《中国科学 数学(英文版)》2012,55(12):2621-2630
Let Xn, n ∈ N be a sequence of non-empty sets, ψn : Xn2 → IR+. We consider the relation E = E((Xn, ψn)n∈N) on ∏n∈N Xn by (x, y) ∈ E((Xn, ψn)n∈N) <=>Σn∈Nψn(x(n), y(n)) < +∞. If E is an equiv- alence relation and all ψn, n ∈ N, are Borel, we show a trichotomy that either IRN/e1≤B E, E1≤B E, or E≤B E0. We also prove that, for a rather general case, E((Xn, ψn)n∈N) is an equivalence relation iff it is an ep-like equivalence relation. 相似文献