共查询到20条相似文献,搜索用时 46 毫秒
1.
Ji-Ming Peng 《Mathematical Programming》1997,78(3):347-355
In this paper we propose a class of merit functions for variational inequality problems (VI). Through these merit functions,
the variational inequality problem is cast as unconstrained minimization problem. We estimate the growth rate of these merit
functions and give conditions under which the stationary points of these functions are the solutions of VI.
This work was supported by the state key project “Scientific and Engineering Computing”. 相似文献
2.
N. Balakrishnan G. Iliopoulos 《Annals of the Institute of Statistical Mathematics》2009,61(3):753-772
In this paper, we present a general method which can be used in order to show that the maximum likelihood estimator (MLE)
of an exponential mean θ is stochastically increasing with respect to θ under different censored sampling schemes. This propery is essential for the construction of exact confidence intervals for
θ via “pivoting the cdf” as well as for the tests of hypotheses about θ. The method is shown for Type-I censoring, hybrid censoring and generalized hybrid censoring schemes. We also establish the
result for the exponential competing risks model with censoring. 相似文献
3.
D. -F. Li 《Fuzzy Optimization and Decision Making》2007,6(3):237-254
The aim of this paper is to develop a new fuzzy closeness (FC) methodology for multi-attribute decision making (MADM) in fuzzy
environments, which is an important research field in decision science and operations research. The TOPSIS method based on
an aggregating function representing “closeness to the ideal solution” is one of the well-known MADM methods. However, while
the highest ranked alternative by the TOPSIS method is the best in terms of its ranking index, this does not mean that it
is always the closest to the ideal solution. Furthermore, the TOPSIS method presumes crisp data while fuzziness is inherent
in decision data and decision making processes, so that fuzzy ratings using linguistic variables are better suited for assessing
decision alternatives. In this paper, a new FC method for MADM under fuzzy environments is developed by introducing a multi-attribute
ranking index based on the particular measure of closeness to the ideal solution, which is developed from the fuzzy weighted
Minkowski distance used as an aggregating function in a compromise programming method. The FC method of compromise ranking
determines a compromise solution, providing a maximum “group utility” for the “majority” and a minimum individual regret for
the “opponent”. A real example of a personnel selection problem is examined to demonstrate the implementation process of the
method proposed in this paper. 相似文献
4.
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
5.
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
6.
Jacob Feldman 《Israel Journal of Mathematics》1980,36(3-4):321-345
A new approach is given to the entropy of a probability-preserving group action (in the context ofZ and ofR
n
), by defining an approximate “r-entropy”, 0<r<1, and lettingr → 0. If the usual entropy may be described as the growth rate of the number of essential names, then ther-entropy is the growth rate of the number of essential “groups of names” of width≦r, in an appropriate sense. The approach is especially useful for actions of continuous groups. We apply these techniques to
state and prove a “second order” equipartition theorem forZ
m
×R
n
and to give a “natural” proof of Ornstein’s isomorphism theorem for Bernoulli actions ofZ
m
×R
n
, as well as a characterization of such actions which seems to be the appropriate generalization of “finitely determined”. 相似文献
7.
A puzzle called “M
13” J. H. Conway has described recently is explained. We report an implementation of the puzzle in the programming language
Java. The program allows the human user to “play M
13” interactively (and to cheat by solving it automatically). The program is an example on how to bring to life a nice piece
of discrete mathematics. In this sense it presents not only a didactical way of seeing “mathematics at work”, but also displays
the stabilizer chain method developed by C. Sims to solve group theoretic puzzles, the most famous of which being Rubik's
cube. 相似文献
8.
Across many industries, e-commerce generates substantial modifications in supply chain structures. The aim of this article
is to assess different forms of existing organizations when a store-based sales network coexists with a web site order network.
Three main organizational models can be detected: “store-picking”, “dedicated warehouse-picking” and “drop-shipping”. We use
a “newsboy” order policy model to compare the advantages of these different models and to note the impact of some parameters
on inventory and flow management policies throughout the supply chain. Several effects are presented, particularly those linked
to the size of the Internet market in relation to traditional market size and market demand hazards.
相似文献
9.
Charles F. Osgood 《Journal of Fourier Analysis and Applications》2001,7(3):309-317
This article treats the problem of the approximation of an analytic function f on the unit disk by rational functions having
integral coefficients, with the goodness of each approximation being judged in terms of the maximum of the absolute values
of the coefficients of the rational function. This relates to the more usual approximation by a rational function in that
it could imply how many decimal places are needed when applying a particularly good rational function approximation having
non-integrad coefficients.
It is shown how to obtain “good” approximations of this type and it is also shown how under certain circumstances “very good”
bounds are not possible. As in diophantine approximation this means that many merely “good” approximations do exist, which
may be the preferable case. The existence or nonexistence of “very good” approximations is closely related to the diophantine
approximation of the first nonzero power series coefficient of at z=0. Nevanlinna theory methods are used in the proofs. 相似文献
10.
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
11.
Masaaki Sibuya 《Annals of the Institute of Statistical Mathematics》1979,31(1):373-390
Summary In this paper we introduce and study new probability distributions named “digamma” and “trigamma” defined on the set of all
positive integers. They are obtained as limits of the zero-truncated Type B3 generalized hypergeometric distributions (inverse
Pólya-Eggenberger or negative binomial beta distributions), and also by compounding the logarithmic series distributions.
The family of digamma distributions has the logarithmic series as a limit and the trigamma as another limit. The trigamma
distributions are very close to the zeta (Zipf) distributions. Thus, our new distributions are useful as substitutes of the
logarithmic series when the observed frequency data have such a long tail that cannot be fitted by the latter distributions.
In the beginning sections we summarize properties of the Type B3 generalized hypergeometric distributions. It is emphasized
that the distributions are obtained by compounding a Poisson distribution by “gamma product-ratio” distributions. 相似文献
12.
A new iterative algorithm based on the inexact-restoration (IR) approach combined with the filter strategy to solve nonlinear
constrained optimization problems is presented. The high level algorithm is suggested by Gonzaga et al. (SIAM J. Optim. 14:646–669,
2003) but not yet implement—the internal algorithms are not proposed. The filter, a new concept introduced by Fletcher and Leyffer
(Math. Program. Ser. A 91:239–269, 2002), replaces the merit function avoiding the penalty parameter estimation and the difficulties related to the nondifferentiability.
In the IR approach two independent phases are performed in each iteration, the feasibility and the optimality phases. The
line search filter is combined with the first one phase to generate a “more feasible” point, and then it is used in the optimality
phase to reach an “optimal” point.
Numerical experiences with a collection of AMPL problems and a performance comparison with IPOPT are provided.
相似文献
13.
The Generalized Riemann Problem (GRP) for a nonlinear hyperbolic system of m balance laws (or alternatively “quasi-conservative” laws) in one space dimension is now well-known and can be formulated
as follows: Given initial-data which are analytic on two sides of a discontinuity, determine the time evolution of the solution
at the discontinuity. In particular, the GRP numerical scheme (second-order high resolution) is based on an analytical evaluation
of the first time derivative. It turns out that this derivative depends only on the first-order spatial derivatives, hence
the initial data can be taken as piecewise linear. The analytical solution is readily obtained for a single equation (m = 1) and, more generally, if the system is endowed with a complete (coordinate) set of Riemann invariants. In this case it
can be “diagonalized” and reduced to the scalar case. However, most systems with m > 2 do not admit such a set of Riemann invariants. This paper introduces a generalization of this concept: weakly coupled
systems (WCS). Such systems have only “partial set” of Riemann invariants, but these sets are weakly coupled in a way which
enables a “diagonalized” treatment of the GRP. An important example of a WCS is the Euler system of compressible, nonisentropic
fluid flow (m = 3). The solution of the GRP discussed here is based on a careful analysis of rarefaction waves. A “propagation of singularities”
argument is applied to appropriate Riemann invariants across the rarefaction fan. It serves to “rotate” initial spatial slopes
into “time derivative”. In particular, the case of a “sonic point” is incorporated easily into the general treatment. A GRP
scheme based on this solution is derived, and several numerical examples are presented. Special attention is given to the
“acoustic approximation” of the analytical solution. It can be viewed as a proper linearization (different from the approach
of Roe) of the nonlinear system. The resulting numerical scheme is the simplest (second-order, high-resolution) generalization
of the Godunov scheme. 相似文献
14.
Flemming Tops?e 《Journal of Global Optimization》2009,43(4):553-564
Inspired by previous work on information theoretical optimization problems, the basics of an axiomatic theory of certain special
two-person zero-sum games is developed. One of the players, “Observer”, is imagined to have a “mind”, the other, “Nature”,
not. These ideas lead to un-symmetric modeling as the two players are treated quite differently. Basic concavity- and convexity
results as well as a general minimax theorem are derived from the axioms. 相似文献
15.
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
16.
William A. Roche 《Acta Analytica》2010,25(2):243-257
Coherentists on epistemic justification claim that all justification is inferential, and that beliefs, when justified, get
their justification together (not in isolation) as members of a coherent belief system. Some recent work in formal epistemology
shows that “individual credibility” is needed for “witness agreement” to increase the probability of truth and generate a
high probability of truth. It can seem that, from this result in formal epistemology, it follows that coherentist justification
is not truth-conducive, that it is not the case that, under the requisite conditions, coherentist justification increases
the probability of truth and generates a high probability of truth. I argue that this does not follow. 相似文献
17.
Karl Sigmund 《Mathematical Intelligencer》2004,26(2):21-33
This column is a forum for discussion of mathematical communities throughout the world, and through all time. Our definition
of “mathematical community” is the broadest. We include “schools” of mathematics, circles of correspondence, mathematical
societies student organizations, and informal communities of cardinality greater than one. What we say about the communities
is just as unrestricted. We welcome contributions from mathematicians of all kinds and in all places, and also from scientists,
historians, anthropologists, and others. 相似文献
18.
Rémi Peyre 《Potential Analysis》2008,29(1):17-36
Carne’s bound is a sharp inequality controlling the transition probabilities for a discrete reversible Markov chain (Section 1).
Its ordinary proof uses spectral techniques which look as efficient as miraculous. Here we present a new proof, comparing
a “drift” for ways “out” and “back”, to get the gaussian part of the bound (Section 2), and using a conditioning technique
to get the flight factor (Section 4). Moreover we show how our proof is more “supple” than Carne’s one and may generalize
(Section 3.2).
相似文献
19.
Rade T. Živaljević 《Discrete and Computational Geometry》2009,41(1):135-161
This paper lays the foundation for a theory of combinatorial groupoids that allows us to use concepts like “holonomy”, “parallel transport”, “bundles”, “combinatorial curvature”, etc. in the context
of simplicial (polyhedral) complexes, posets, graphs, polytopes and other combinatorial objects. We introduce a new, holonomy-type
invariant for cubical complexes, leading to a combinatorial “Theorema Egregium” for cubical complexes that are non-embeddable
into cubical lattices. Parallel transport of Hom-complexes and maps is used as a tool to extend Babson–Kozlov–Lovász graph coloring results to more general statements about
nondegenerate maps (colorings) of simplicial complexes and graphs.
The author was supported by grants 144014 and 144026 of the Serbian Ministry of Science and Technology. 相似文献
20.
This column is a forum for discussion of mathematical communities throughout the world, and through all time. Our definition
of “mathematical community” is the broadest. We include “schools” of mathematics, circles of correspondence, mathematical
societies, student organizations, and informal communities of cardinality greater than one. What we say about the communities
is just as unrestricted. We welcome contributions from mathematicians of all kinds and in all places, and also from scientists,
historians, anthropologists, and others. 相似文献