共查询到20条相似文献,搜索用时 31 毫秒
1.
John N. Mather 《Commentarii Mathematici Helvetici》1982,57(1):356-376
Percival introduced a “Lagrangian” for finding quasi-periodic orbits. For suitable area preserving mappings, we show that
Percival's “Lagrangian” is strictly concave with respect to an appropriate affine structure on its domain. Consequently, the
“Lagrangian” admits a unique maximum in the case of irrational frequencies.
Supported by NSF grant MCS 79-02017 相似文献
2.
The ancient record, “During the first year of King Yi, the day dawned twice at Zheng”, has provided important clues to early
Chinese chronicles. The astronomical conditions and visible area distributions related to such a “double dawn” event are discussed,
and the precision and current problems in the calculations of ancient astronomical phenomena are shown. On such a basis, all
the solar eclipses from 1000 BC to 840 BC are calculated and their associated “double dawn” features investigated. The conclusion
that the “double dawn” was a solar eclipse occurring on April 21st, 899 BC is corfirmed to be the most reasonable.
Project supported by the Xia-Shang-Zhou Chronology Project and Director Foundation of the Chinese Academy of Sciences. 相似文献
3.
Alessio Moretti 《Logica Universalis》2009,3(1):19-57
Whereas geometrical oppositions (logical squares and hexagons) have been so far investigated in many fields of modal logic
(both abstract and applied), the oppositional geometrical side of “deontic logic” (the logic of “obligatory”, “forbidden”,
“permitted”, . . .) has rather been neglected. Besides the classical “deontic square” (the deontic counterpart of Aristotle’s
“logical square”), some interesting attempts have nevertheless been made to deepen the geometrical investigation of the deontic
oppositions: Kalinowski (La logique des normes, PUF, Paris, 1972) has proposed a “deontic hexagon” as being the geometrical
representation of standard deontic logic, whereas Joerden (jointly with Hruschka, in Archiv für Rechtsund Sozialphilosophie
73:1, 1987), McNamara (Mind 105:419, 1996) and Wessels (Die gute Samariterin. Zur Struktur der Supererogation, Walter de Gruyter,
Berlin, 2002) have proposed some new “deontic polygons” for dealing with conservative extensions of standard deontic logic
internalising the concept of “supererogation”. Since 2004 a new formal science of the geometrical oppositions inside logic
has appeared, that is “n-opposition theory”, or “NOT”, which relies on the notion of “logical bi-simplex of dimension m” (m = n − 1). This theory has received a complete mathematical foundation in 2008, and since then several extensions. In this paper,
by using it, we show that in standard deontic logic there are in fact many more oppositional deontic figures than Kalinowski’s
unique “hexagon of norms” (more ones, and more complex ones, geometrically speaking: “deontic squares”, “deontic hexagons”,
“deontic cubes”, . . ., “deontic tetraicosahedra”, . . .): the real geometry of the oppositions between deontic modalities
is composed by the aforementioned structures (squares, hexagons, cubes, . . ., tetraicosahedra and hyper-tetraicosahedra),
whose complete mathematical closure happens in fact to be a “deontic 5-dimensional hyper-tetraicosahedron” (an oppositional
very regular solid).
相似文献
4.
Gábor Czédli 《Mathematica Slovaca》2011,61(6):859-870
For each of the relations “less than or equal to”, “less than”, “covered by”, and “covered by or equal to”, we characterize
finite orders (also called posets) with the property that the pair of Galois closure operators induced by the relation in
question coincides with the pair of closure operators introduced and applied in our previous paper in 2007. We also consider
the “less than or equal to” relation between the set of join-irreducible elements and the set of meet-irreducible elements,
and we show that the above-mentioned pairs of closure operators coincide for finite modular lattices. 相似文献
5.
Ahlswede Rudolf Khachatrian Levon H. Mauduit C. Sárközy A. 《Periodica Mathematica Hungarica》2003,46(2):107-118
In earlier papers finite pseudorandom binary sequences were studied, quantitative measures of pseudorandomness of them were
introduced and studied, and large families of “good” pseudorandom sequences were constructed. In certain applications (cryptography)
it is not enough to know that a family of “good” pseudorandom binary sequences is large, it is a more important property if
it has a “rich”, “complex” structure. Correspondingly, the notion of “f-complexity” of a family of binary sequences is introduced. It is shown that the family of “good” pseudorandom binary sequences
constructed earlier is also of high f-complexity. Finally, the cardinality of the smallest family achieving a prescibed f-complexity and multiplicity is estimated.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
6.
Summary As a criterion for the reduction to a complete class of decision rule in case where actions, samples and states are finite
in number, “regret-relief ratio” criterion and “incremental loss-gain ratio” criterion were introduced in 2-state of nature
case [2]. In this paper, “generalized regret-relief ratio” criterion ink-state of nature case is introduced as an extension of “regret-relief ratio” criterion and its usefulness is shown with an
example.
The Institute of Statistical Mathematics 相似文献
7.
Nikola Kompa 《Acta Analytica》2005,20(1):16-28
The basic idea of conversational contextualism is that knowledge attributions are context sensitive in that a given knowledge
attribution may be true if made in one context but false if made in another, owing to differences in the attributors’ conversational
contexts. Moreover, the context sensitivity involved is traced back to the context sensitivity of the word “know,” which,
in turn, is commonly modelled on the case either of genuine indexicals such as “I” or “here” or of comparative adjectives
such as “tall” or “rich.” But contextualism faces various problems. I argue that in order to solve these problems we need
to look for another account of the context sensitivity involved in knowledge attributions and I sketch an alternative proposal. 相似文献
8.
Shyūichi Izumiya 《manuscripta mathematica》1979,28(4):337-360
In his paper [2], Bierstone proves the equivariant Gromov theorem which is an integrability theorem for “open regularity condition”
of equivariant sections of a smooth G-fibre bundle under the assumption that all orbit bundles of base manifold are non-closed.
Here, we prove the result without his assumption under a nice “open regularity condition” which we call “G-extensible”.
One of the examples of “G-extensible condition” is given by notions of Thom-Boardman singularities. 相似文献
9.
We study Lebesgue and Atsuji spaces within subsystems of second order arithmetic. The former spaces are those such that every
open covering has a Lebesgue number, while the latter are those such that every continuous function defined on them is uniformly
continuous. The main results we obtain are the following: the statement “every compact space is Lebesgue” is equivalent to
; the statements “every perfect Lebesgue space is compact” and “every perfect Atsuji space is compact” are equivalent to ; the statement “every Lebesgue space is Atsuji” is provable in ; the statement “every Atsuji space is Lebesgue” is provable in . We also prove that the statement “the distance from a closed set is a continuous function” is equivalent to .
Received: February 2, 1996 相似文献
10.
J. Sakalauskaitė 《Lithuanian Mathematical Journal》2007,47(3):266-276
In this paper, we consider branching time temporal logic CT L with epistemic modalities for knowledge (belief) and with awareness operators. These logics involve the discrete-time linear
temporal logic operators “next” and “until” with the branching temporal logic operator “on all paths”. In addition, the temporal
logic of knowledge (belief) contains an indexed set of unary modal operators “agent i knows” (“agent i believes”). In a language of these logics, there are awareness operators. For these logics, we present sequent calculi with
a restricted cut rule. Thus, we get proof systems where proof-search becomes decidable. The soundness and completeness for
these calculi are proved.
Published in Lietuvos Matematikos Rinkinys, Vol. 47, No. 3, pp. 328–340, July–September, 2007. 相似文献
11.
We study the properties of the ergosurface of the Pomeransky–Senkov black rings, and show that it splits into an “inner” and
an “outer” region. As for the singular set, the topology of the “outer ergosurface” depends upon the value of parameters. 相似文献
12.
T. V. Panchapagesan 《Rendiconti del Circolo Matematico di Palermo》1995,44(3):417-440
The concept of an orthogonal spectral representation (OTSR) of a Hilbert spaceH relative to a spectral measureE(.) is introduced and it is shown that every Hilbert space admits an OTSR relative to a given spectral measure. Apart from
the various results obtained about OTSRs, the principal result of Allan Brown (1974) is deduced as an easy consequence of
this study. A new complete system of unitary invariants called the “equivalence of OTSRs”, is given for spectral measures.
Two special types of OTSRs called “BOTSR” and “COBOTSR” are introduced and characterized respectively in terms of the “GCGS-property”
and “CGS-property” of the associated spectral measure. Various complete systems of unitary invariants are given for spectral
measures with the GCGS-property. Finally, the Wecken-Plesner-Rohlin theorem on hermitian operators with simple spectra is
generalized to arbitrary spectral measures. 相似文献
13.
14.
In this paper, we study the temporal logic S4Dbr with two temporal operators “always” and “eventually.” An equivalent sequent
calculus is presented with formulae as modal clauses or modal clauses starting with operator “always.” An upper bound of deduction
tree is given for propositional logic. A theorem prover for propositional logic is written in SWI-Prolog.
Published in LietuvosMatematikos Rinkinys, Vol. 46, No. 2, pp. 203–214, April–June, 2006. 相似文献
15.
Shmuel Rosset 《Israel Journal of Mathematics》1981,39(3):255-258
We prove that the Brauer class of a crossed product is a sum of symbols iff its “local” components are. Analogously we show
that a solution of the “Goldie rank conjecture” would follow from the “local” statements; an extension of a result of Cliff-Sehgal
is an easy corollary. 相似文献
16.
Alessandra Celletti Luigi Chierchia 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2005,57(1):33-41
A new (iso-energetic) KAM method is tested on a specific three-body problem “extracted” from the Solar system (Sun-Jupiter
+ asteroid 12 Victoria). Analytical results in agreement with the observed data are established. This paper is a concise presentation
of [2].
Supported by the MIUR projects: “Dynamical Systems: Classical, Quantum, Stochastic” and “Variational Methods and Nonlinear
Differential Equations”
Received: February 3, 2004 相似文献
17.
Sylvia Chiang 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2006,151(1):940-959
We study the pressureless gas equations, with piecewise constant initial data. In the immediate solution, δ-shocks and contact
vacuum states arise and even meet (interact) eventually. A solution beyond the “interaction” is constructed. It shows that
the δ-shock will continue with the velocity it attained instantaneously before the time of interaction, and similarly, the
contact vacuum state will move past the δ-shock with a velocity value prior to the interaction. We call this the “no-effect-from-interaction”
solution.
We prove that this solution satisfies a family of convex entropies (in the Lax’s sense). Next, we construct an infinitely
large family of weak solutions to the “interaction”. Suppose further that any of these solutions satisfy a convex entropy,
it is necessary and suffcient that these solutions reduce to only the “no-effect-from-interaction” solution. In [1], Bouchut
constructed another entropy satisfying solution. As with other previous papers, it is obvious that it will not be sufficient
that a “correct” solution satisfies a convex entropy, in a non-strictly hyperbolic conservation laws system. 相似文献
18.
Harry Cohn 《Israel Journal of Mathematics》1972,12(1):11-16
A new variant of the “divergent” part of the Borel-Cantelli lemma for events derived from a Markov chain is given. Further
two applications are considered. One of the applications refers to the denumerable Markov chain and the second is a new proof
of the “strong” theorem corresponding to the “arc sine law”. 相似文献
19.
I. V. Blinova V. V. Gusarov I. Yu. Popov 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2009,8(2):178-188
“Almost quasistationary” approximation is suggested for the investigation of the problem of solidification front stability.
It is appropriate for the initial stage of the process when sizes of particles are sufficiently small. The cases of “sphere
like” and “cylinder-like” nuclei are considered. Capillary forces are taken into account. 相似文献
20.
The Zubarev nonequilibrium statistical operator is used to describe the generalized hydrodynamic state of a magnetic fluid
in an external magnetic field. The magnetic fluid is modeled with “liquid-state” and “magnetic” subsystems described using
the classical and quantum statistics methods respectively. Equations of the generalized statistical hydrodynamics for a magnetic
fluid in a nonhomogeneous external magnetic field with the Heisenberg spin interaction are derived for “liquid-state” and
“magnetic” subsystems characterized by different nonequilibrium temperatures. These equations can be used to describe both
the weakly and strongly nonequilibrium states. Some limiting cases are analyzed in which the variables of one of the subsystems
can be formally neglected.
Translated from Teoreticheskaya i Matematicheskaya Fizika. Vol. 115, No. 1, pp. 132–153, April, 1998. 相似文献