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71.
Iain A. Stewart 《Mathematical Logic Quarterly》1997,43(1):1-21
We investigate the definability in monadic ∑11 and monadic Π11 of the problems REGk, of whether there is a regular subgraph of degree k in some given graph, and XREGk, of whether, for a given rooted graph, there is a regular subgraph of degree k in which the root has degree k, and their restrictions to graphs in which every vertex has degree at most k, namely REGkk and XREGkk, respectively, for k ≥ 2 (all our graphs are undirected). Our motivation partly stems from the fact (which we prove here) that REGkk and XREGkk are logspace equivalent to CONN and REACH, respectively, for k ≥ 3, where CONN is the problem of whether a given graph is connected and REACH is the problem of whether a given graph has a path joining two given vertices. We use monadic first - order reductions, monadic ∑11 games and a recent technique due to Fagin, Stockmeyer and Vardi to almost completely classify whether these problems are definable in monadic ∑11 and monadic Π11, and we compare the definability of these problems (in monadic ∑11 and monadic Π11 with their computational complexity (which varies from solvable using logspace to NP - complete). 相似文献
72.
Herman Dishkant 《Fuzzy Sets and Systems》1981,5(2):141-147
A logical approach to fuzzy sets method originated by Giles is developed. The infinitely many-valued logic tω is taken as basic. We accept, it is correct to use the strong conjunction by the logical analysis of the summation of fuzzy items. Under some broad conditions it is proved. that the sum of many fuzzy variables is a variable whose membership function is approximately equal to , where a and c are some constant parameters. A method of estimation of the unknown parameters is developed in a general case. The proposed fuzzy method coincides with the method of maximum likelihood if used in problems of classical mathematical statistics. 相似文献
73.
We present an alternative, purely semantical and relatively simple, proof of the Statman's result that both intuitionistic propositional logic and its implicational fragment are PSPACE-complete.This paper was supported by grant 401/01/0218 of the Grant Agency of the Czech Republic. %
Mathematics Subject Classification (2000): 相似文献
74.
电流控阈技术及三值电流型 CMOS施密特电路 总被引:1,自引:1,他引:0
本文以开关信号理论为指导 ,对电流型 CM OS电路中如何实现阈值控制进行研究. 建立实现阈 值控制电路的电流传输开关运算 ,并用于指导电流型 CMOS施密特电路的开关级设计 .用 PSPICE程序 模拟证明了所设计的电路具有理想的施密特电路特性. 相似文献
75.
Richard Massy 《Journal of Number Theory》2005,113(2):244-275
In this paper, we introduce a notion of “Galois average” which allows us to give a suitable answer to the question: how can one extend a finite Galois extension E/F by a prime degree extension N/E to get a Galois extension N/F? Here, N/E is not necessarily a Kummer extension. 相似文献
76.
运用开关信号理论和有界算术运算理论,对电流镜的多种性质进行了讨论,并系统研究了利用电流镜实现电流信号的各种算术运算,其中倍除运算属于初次提出,最后通过N进制半加电路和N值比较电路等两个设计实例介绍了电流镜技术在I^2L电路开关级设计中的应用。 相似文献
77.
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79.
Elias Zafiris 《International Journal of Theoretical Physics》2004,43(1):265-298
We develop a relativistic perspective on structures of quantum observables, in terms of localization systems of Boolean coordinatizing charts. This perspective implies that the quantum world is comprehended via Boolean reference frames for measurement of observables, pasted together along their overlaps. The scheme is formalized categorically, as an instance of the adjunction concept. The latter is used as a framework for the specification of a categorical equivalence signifying an invariance in the translational code of communication between Boolean localizing contexts and quantum systems. Aspects of the scheme semantics are discussed in relation to logic. The interpretation of coordinatizing localization systems, as structure sheaves, provides the basis for the development of an algebraic differential geometric machinery suited to the quantum regime. 相似文献
80.
Florian D. Jochum F. Romina Forst Patrick Theato 《Macromolecular rapid communications》2010,31(16):1456-1461
A series of thermo‐responsive PNIPAM copolymers containing different amounts of fulgimide moieties has been synthesized via a polymer analogous reaction of poly(pentafluorophenyl acrylate). All copolymers were designed to exhibit a lower critical solution temperature (LCST) in water, which was only weakly dependent on the amount of incorporated chromophoric fulgimide groups. The copolymers showed a photocyclization of the fulgimide side groups upon irradiation with UV‐light accompanied with a color change. The closed form of the chromophore had a halftime of 136 min for the visible reisomerization and did not affect the LCST of the polymer. This led to the realization of a logic “NOT A” for the fulgimide containing PNIPAM, while a corresponding azobenzene containing PNIPAM resulted in a different logic “A implies B”.