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1.
A natural way to prove that a particular linear extension of an ordered set is ‘optimal’ with respect to the ‘jump number’
is to transform this linear extension ‘canonically’ into one that is ‘optimal’. We treat a ‘greedy chain interchange’ transformation
which has applications to ordered sets for which each ‘greedy’ linear extension is ‘optimal’. 相似文献
2.
Joseph G. Moore 《Acta Analytica》2010,25(1):89-103
The paper is a critical discussion of the rich and insightful final chapter of Mitchell Green’s Self-Expression. There, Green seeks to elucidate the compelling, but inchoate intuition that when we’re fully and most expertly expressing
ourselves, we can ‘push out’ from within not just our inner representations, but also the ways that we feel. I question, first,
whether this type of ‘qualitative expression’ is really distinct from the other expressive forms that Green explores, and
also whether it’s genuinely ‘expressive’. I then scrutinize the nature of the ‘qualitative congruences’ that lie at the heart
of Green’s theory; and I wonder whether they can play the role Green claims they can in providing a novel account of artistic
expression. 相似文献
3.
Sur les espaces fonctionnels dont la source est le classifiant d’un groupe de Lie compact commutatif
Résumé Nous montrons dans cet article comment les connaissances acquises sur les espaces fonctionnels de source le classifiant du
groupeZ/p ([La2], [DS]) et l’utilisation de MU-résolutions instables permettent d’obtenir des résultats sur les espaces fonctionnels
de source le classifiant d’unp-groupe abélien fini ou d’un tore si l’on impose au but d’avoir une cohomologie à coefficientsp-adiques sans torsion. Nous montrons notamment que l’ensemble des classes d’homotopie d’applications du classifiant X d’un
tore dans un espace Y simplement connexe dont l’homologie entière est nulle en degré impair et un groupe abélien libre de
dimension finie en chaque degré pair, et dont la cohomologie rationnelle est polynomiale, s’identifie à l’ensemble des applications
de la K-théorie de Y dans la K-théorie de X qui préservent la structure de λ-anneau.
Le premier auteur a bénéficié pendant l’achèvement de ce travail d’une allocation de recherche de l’école Polytechnique. 相似文献
4.
The paper is concerned with the ‘primal’ problem of maximizing a given quadratic pseudo-boolean function. Four equivalent
problems are discussed—the primal, the ‘complementation’, the ‘discrete Rhys LP’ and the ‘weighted stability problem of a
SAM graph’. Each of them has a relaxation—the ‘roof dual’, the ‘quadratic complementation,’ the ‘continuous Rhys LP’ and the
‘fractional weighted stability problem of a SAM graph’. The main result is that the four gaps associated with the four relaxations
are equal. Furthermore, a solution to any of these problems leads at once to solutions of the other three equivalent ones.
The four relaxations can be solved in polynomial time by transforming them to a bipartite maximum flow problem. The optimal
solutions of the ‘roof-dual’ define ‘best’ linear majorantsp(x) off, having the following persistency property: if theith coefficient inp is positive (negative) thenx
i=1 (0) in every optimum of the primal problem. Several characterizations are given for the case where these persistency results
cannot be used to fix any variable of the primal. On the other hand, a class of gap-free functions (properly including the
supermodular ones) is exhibited. 相似文献
5.
Sandra Herbert Robyn Pierce 《International Journal of Computers for Mathematical Learning》2008,13(3):231-249
Does speed provide a ‘model for’ rate of change in other contexts? Does JavaMathWorlds (JMW), animated simulation software,
assist in the development of the ‘model for’ rate of change? This project investigates the transference of understandings
of rate gained in a motion context to a non-motion context. Students were 27 14–15 year old students at an Australian secondary
school. The instructional sequence, utilising JMW, provided rich learning experiences of rate of change in the context of
a moving elevator. This context connects to students’ prior knowledge. The data taken from pre- and post-tests and student
interviews revealed a wide variation in students’ understanding of rate of change. The variation was mapped on a hypothetical
learning trajectory and interpreted in the terms of the ‘emergent models’ theory (Gravemeijer, Math Think Learn 1(2):155–177,
1999) and illustrated by specific examples from the data. The results demonstrate that most students were able to use the
‘model of’ rate of change developed in a vertical motion context as a ‘model for’ rate of change in a horizontal motion context.
A smaller majority of students were able to use their, often incomplete, ‘model of’ rate of change as a ‘model for’ reasoning
about rate of change in a non-motion context. 相似文献
6.
Semën S. Podkorytov 《Central European Journal of Mathematics》2011,9(6):1232-1241
Following a Bendersky-Gitler idea, we construct an isomorphism between Anderson’s and Arone’s complexes modelling the chain
complex of a mapping space. This allows us to apply Shipley’s convergence theorem to Arone’s model. As a corollary, we reduce
the problem of homotopy equivalence for certain “toy” spaces to a problem in homological algebra. 相似文献
7.
8.
The purpose of this study is to explore how students changes through learning to construct mathematical proofs in an inquiry-based middle school geometry class in Korea. Although proof has long been considered as one of the most important aspects of mathematics education, it is well-known that it is one of the most difficult areas of school mathematics for students. The geometry inquiry classroom (GIC) is an experimental class designed to teach geometry, especially focusing on teaching proof, based on students’ own inquiry. Based on a 2-year participant observation in the GIC, this study was conducted to address the following research question: how has students’ practice of mathematical proof been changed through their participation in the GIC? The in-depth analysis of the classroom discourse identified three stages through which the students’ practice of mathematical proof was transformed in the GIC: ‘emergent understanding of proof’, ‘proof learning as a goal-oriented activity’, ‘experiencing proof as the practice of mathematics’. The study found that as learning evolved through these stages, so the mathematics teacher’s role shifted from being an instructor to a mediator of communication. Most importantly, this research showed that the GIC has created a learning environment where students develop their competence in constructing meaningful mathematical proof and grow to be ‘a human who proves’, ultimately ‘a person who playfully engages with mathematics’. 相似文献
9.
Aristophanes Koutoungos 《Acta Analytica》2005,20(3):59-79
Moral internalism and moral externalism compete over the best explanation of the link between judgment and relevant motivation
but, it is argued, they differ at best only verbally. The internalist rational-conceptual nature of the link’ as accounted
by M. Smith in The Moral Problem is contrasted to the externalist, also rational, link that requires in addition support from
the agent’s psychological-dispositional profile; the internalist link, however, is found to depend crucially on a, similarly
to the externalist, psychologically ‘loaded’ profile. It is also argued that the differentiation of the two competing explanations
is insufficient partly because they both fail to consider crucial quantitative parameters of the judgment-motivation link.
Such parameters become very important particularly in the light of Smith’s claim that this link is grounded on the observable
“striking fact” where changes in the set of one’s moral beliefs systematically bring about changes in one’s moral behavior.
Examples of algorithms measuring moral coherence and moral worth are provided to serve as evidence for what it comes down
to, vis-à-vis the alleged fact, only a verbal dispute between the two camps. Finally, the ‘misfiring’ of these explanations
is understood in connection to the irreducibility of concepts such as ‘moral worth’, and/or, ‘moral sensitivity’. 相似文献
10.
Nonholonomic systems are described by the Lagrange-D’Alembert’s principle. The presence of symmetry leads, upon the choice
of an arbitrary principal connection, to a reduced D’Alembert’s principle and to the Lagrange-D’Alembert-Poincaré reduced
equations. The case of rolling constraints has a long history and it has been the purpose of many works in recent times. In
this paper we find reduced equations for the case of a thick disk rolling on a rough surface, sometimes called Euler’s disk, using a 3-dimensional abelian group of symmetry. We also show how the reduced system can be transformed into a single second
order equation, which is an hypergeometric equation. 相似文献
11.
In this paper, an interactive paired comparison simplex based method formultiple objective linear programming (MOLP) problems
is developed and compared to other interactive MOLP methods. The decision maker (DM)’s utility function is assumed to be unknown,
but is an additive function of his known linearized objective functions. A test for ‘utility efficiency’ for MOLP problems
is developed to reduce the number of efficient extreme points generated and the number of questions posed to the DM. The notion
of ‘strength of preference ’ is developed for the assessment of the DM’s unknown utility function where he can express his
preference for a pair of extreme points as ‘strong ’, ‘weak ’, or ‘almost indifferent ’. The problem of ‘inconsistency of
the DM’ is formalized and its resolution is discussed. An example of the method and detailed computational results comparing
it with other interactive MOLP methods are presented. Several performance measures for comparative evaluations of interactive
multiple objective programming methods are also discussed.
All rights reserved. This study, or parts thereof, may not be reproduced in any form without written permission of the authors. 相似文献
12.
Isabel Parra-Frutos 《Computational Statistics》2009,24(4):671-693
This is a simulation study that analyzes the robustness properties of tests for equality of variances in terms of both, Type
I error rate and power. The well-known Levene’s and Bartlett’s tests, along with different modifications proposed for Levene’s
test with and without bootstrapping are examined. Without bootstrapping, some of the modifications may produce better homogeneity
tests. Bootstrapping Levene’s test based on the median and this test simultaneously modified by Keyes–Levy’s adjustment and
Satterthwaite’s correction are always robust for the significance level under any kind of distribution and combination of
sample sizes. None of the tests examined provides protection against extreme values in symmetric distributions. 相似文献
13.
Atsushi Moriwaki 《Inventiones Mathematicae》2000,140(1):101-142
In this paper, we propose a new height function for a variety defined over a finitely generated field over ℚ. For this height
function, we prove Northcott’s theorem and Bogomolov’s conjecture, so that we can recover the original Raynaud’s theorem (Manin-Mumford’s
conjecture).
Oblatum 7-VI-1999 & 21-IX-1999 / Published online: 24 January 2000 相似文献
14.
Seahwa Kim 《Acta Analytica》2012,27(1):73-76
In this paper, I examine Takashi Yagisawa’s response to van Inwagen’s ontic objection against David Lewis. Van Inwagen criticizes
Lewis’s commitment to the absolutely unrestricted sense of ‘there is,’ and Yagisawa claims that by adopting modal tenses he
avoids commitment to absolutely unrestricted quantification. I argue that Yagisawa faces a problem parallel to the one Lewis
faces. Although Yagisawa officially rejects the absolutely unrestricted sense of a quantifying expression, he is still committed
to the absolutely unrestricted sense of ‘is
a
real.’ 相似文献
15.
On the Equivalence and Generalized of Weyl Theorem Weyl Theorem 总被引:3,自引:0,他引:3
M. BERKANI 《数学学报(英文版)》2007,23(1):103-110
We know that an operator T acting on a Banach space satisfying generalized Weyl's theorem also satisfies Weyl's theorem. Conversely we show that if all isolated eigenvalues of T are poles of its resolvent and if T satisfies Weyl's theorem, then it also satisfies generalized Weyl's theorem. We give also a sinlilar result for the equivalence of a-Weyl's theorem and generalized a-Weyl's theorem. Using these results, we study the case of polaroid operators, and in particular paranormal operators. 相似文献
16.
Wolfgang Barz 《Acta Analytica》2007,22(3):183-188
It is argued that Searle’s argument for the thesis that there is a conceptual connection between intentionality and consciousness
suffers from serious ambiguities. Searle’s argument is reconstructed as consisting of three premises that contain the notions
of aspectual shape and irreducible subjectivity. Having identified two different readings of ‘aspectual shape’ and ‘irreducibly
subjective,’ I conclude that each version of Searle’s argument incorporates at least one false premise.
This paper is a descendant of a paper presented at the Wittgenstein Symposium at Kirchberg am Wechsel in August 2004. I would
like to thank the reviewer of this journal for his/her helpful comments on a previous draft. 相似文献
17.
James Hirschorn 《Israel Journal of Mathematics》2007,157(1):123-153
We extend Jensen’s Theorem that Souslin’s Hypothesis is consistent with CH, by showing that the statement Souslin’s Hypothesis holds in any forcing extension by a measure algebra is consistent with CH. We also formulate a variation of the principle (*) (see [AT97], [Tod00]) for closed sets of ordinals,
and show its consistency relative to the appropriate large cardinal hypothesis. Its consistency with CH would extend Silver’s
Theorem that, assuming the existence of an inaccessible cardinal, the failure of Kurepa’s Hypothesis is consistent with CH,
by its implication that the statement Kurepa’s Hypothesis fails in any forcing extension by a measure algebra is consistent with CH. 相似文献
18.
In this paper, a simple probabilistic model of coalition formation provides a unified interpretation for several extensions
of the Shapley value. Weighted Shapley values, semivalues, weak (weighted or not) semivalues, and the Shapley value itself
appear as variations of this model. Moreover, some notions that have been introduced in the search of alternatives to Shapley’s
seminal characterization, as ‘balanced contributions’ and the ‘potential’ are reinterpreted from this point of view. Natural
relationships of these conditions with some mentioned families of ‘values’ are shown. These reinterpretations strongly suggest
that these conditions are more naturally interpreted in terms of coalition formation than in terms of the classical notion
of ‘value.’
相似文献
19.
Cyril Demarche 《Mathematische Annalen》2010,346(4):949-968
On s’intéresse au groupe de Brauer d’une compactification lisse d’un espace homogène d’un groupe semi-simple simplement connexe
à stabilisateurs finis, sur un corps de nombres. On montre une formule décrivant ce groupe de Brauer et on calcule explicitement
celui-ci pour certaines familles d’exemples. On établit des liens entre l’obstruction de Brauer–Manin à l’approximation faible
sur cet espace homogène et la cohomologie galoisienne du stabilisateur. 相似文献
20.
In the class of linear continuous operators that act in the spaces of functions analytic in domains, we describe, in various
forms, isomorphisms that commute with a power of the Gel’fond–Leont’ev generalized integration operator. We also obtain representations
of all closed subspaces of the space of analytic functions that are invariant with respect to a power of the Gel’fond–Leont’ev
generalized integration operator. 相似文献