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51.
资源有限的加权总完工时间单机排序问题 总被引:1,自引:0,他引:1
本讨论资源有限的加权总工时间单机排序问题,对现在仍为OPEN问题1|pj=bj-ajuj,∑uj≤U|∑wjCj给出了一个有关最优解中最优资源分配的重要性质,并利用该性质分别给出了三种情况bj=b,wj=w,aj=a;bj=b,wj=w,uj=u;aj=a,wj=w,uj=u的最优算法。 相似文献
52.
53.
Sébastien Lemaire Giuliano Giambastiani Barbara Pacini Giovanni Poli 《Journal of organometallic chemistry》2003,687(2):291-300
A new type I palladium-catalyzed pseudo-domino process is developed, in which a single Pd-based catalytic system promotes two mechanistically unrelated, sequential catalytic cycles in chronologically distinct order. Suitable precursors undergo an allylic alkylation and a Heck coupling in sequence, affording polycondensed pyrrolidone derivatives. Depending on the starting precursors, intra/inter or doubly intramolecular processes can be obtained. The allylic alkylation process takes place always very smoothly. On the other hand, the Heck coupling turns out to be rather difficult either when the process is intermolecular, or when an intramolecular process generates polycondensed structures featuring three fused bonds connected to a common carbon atom. In such difficult cases, use of the Herrmann-Beller phosphapalladacycle allowed to catalyze the coupling. This study demonstrates also that allylic alkylations can be catalyzed by the Herrmann-Beller phosphapalladacycle. 相似文献
54.
55.
We present a practical polynomial-time algorithm for computing the
zeta function of a Kummer curve over a finite field of small
characteristic. Such algorithms have recently been obtained using a
method of Kedlaya based upon Monsky–Washnitzer cohomology, and are of
interest in cryptography. We take a different approach.
The problem is reduced to that of computing the L-function
of a multiplicative character sum. This latter task is achieved via a
cohomological formula based upon the work of Dwork and Reich. We show,
however, that our method and that of Kedlaya are very closely related.Dedicated to the memory of Gian-Carlo Rota 相似文献
56.
57.
Phase modulation in dipolar-coupled A2 spin systems: effect of maximum state mixing in H NMR in vivo
Leif Schrder Christian Schmitz Peter Bachert 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2004,171(2):69
Coupling constants of nuclear spin systems can be determined from phase modulation of multiplet resonances. Strongly coupled systems such as citrate in prostatic tissue exhibit a more complex modulation than AX connectivities, because of substantial mixing of quantum states. An extreme limit is the coupling of n isochronous spins (An system). It is observable only for directly connected spins like the methylene protons of creatine and phosphocreatine which experience residual dipolar coupling in intact muscle tissue in vivo. We will demonstrate that phase modulation of this “pseudo-strong” system is quite simple compared to those of AB systems. Theory predicts that the spin-echo experiment yields conditions as in the case of weak interactions, in particular, the phase modulation depends linearly on the line splitting and the echo time. 相似文献
58.
PinHuaLI LeiWANG MinWANG JinCanYAN 《中国化学快报》2004,15(11):1295-1298
A Glaser coupling reaction of terminal alkynes in the presence of nickel chloride withoutany organics and bases in hot water has been developed, which produces the correspondinghomo-coupling products in good yields. 相似文献
59.
In this paper we focus on the problem of identifying the index sets P(x):=i|xi>0, N(x):={i|Fi(x)>0 and C(x):=i|xi=Fi(x)=0} for a solution x of the monotone nonlinear complementarity problem NCP(F). The correct identification of these sets is important from both theoretical and practical points of view. Such an identification enables us to remove complementarity conditions from the NCP and locally reduce the NCP to a system which can be dealt with more easily. We present a new technique that utilizes a sequence generated by the proximal point algorithm (PPA). Using the superlinear convergence property of PPA, we show that the proposed technique can identify the correct index sets without assuming the nondegeneracy and the local uniqueness of the solution.This work was supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture of Japan.Mathematics Subject Classification (2000): 90C33, 65K10 相似文献
60.
Clemens Heuberger 《Periodica Mathematica Hungarica》2004,49(2):65-89
We study digit expansions with arbitrary integer digits in base q (q integer) and the Fibonacci base such that the sum of the absolute values of the digits is minimal. For the Fibonacci case, we describe a unique minimal expansion and give a greedy algorithm to compute it. Additionally, transducers to calculate minimal expansions from other expansions are given. For the case of even integer bases q, similar results are given which complement those given in [6]. 相似文献