Results 1  10
of
144
i GOLDEN CUBOID SEQUENCES
, 1983
"... The notion of a golden cuboid as a generalization of a golden rectangle was first introduced by Huntley [1], where it appears as a rectangular parallelepiped with edges 1, (f), and (J) 2. In this paper, we proceed from a somewhat different point of view by first recalling that a golden rectangle may ..."
Abstract
 Add to MetaCart
cuboid " (Theorem 1). Theorem 2 establishes a nested sequence of golden cuboids analogous to the wellknown sequence of nested golden rectangles. An unexpected application occurs in [2] with the construction of an interpretative model for a disputed passage of Vlato*s Timaeus, lines 31b32c
Improving Exhaustive Search Implies Superpolynomial Lower Bounds
, 2009
"... The P vs NP problem arose from the question of whether exhaustive search is necessary for problems with short verifiable solutions. We do not know if even a slight algorithmic improvement over exhaustive search is universally possible for all NP problems, and to date no major consequences have been ..."
Abstract

Cited by 37 (7 self)
 Add to MetaCart
The P vs NP problem arose from the question of whether exhaustive search is necessary for problems with short verifiable solutions. We do not know if even a slight algorithmic improvement over exhaustive search is universally possible for all NP problems, and to date no major consequences have been
Akademisk avhandling för teknisk doktorsexamen vid
, 1994
"... mcmxciv This thesis deals with combinatorics in connection with Coxeter groups, finitely generated but not necessarily finite. The representation theory of groups as nonsingular matrices over a field is of immense theoretical importance, but also basic for computational group theory, where the group ..."
Abstract
 Add to MetaCart
mcmxciv This thesis deals with combinatorics in connection with Coxeter groups, finitely generated but not necessarily finite. The representation theory of groups as nonsingular matrices over a field is of immense theoretical importance, but also basic for computational group theory, where the group elements are data structures in a computer. Matrices are unnecessarily large structures, and part of this thesis is concerned with small and efficient representations of a large class of Coxeter groups (including most Coxeter groups that anyone ever payed any attention to.) The main contents of the thesis can be summarized as follows. • We prove that for all Coxeter graphs constructed from an npath of unlabelled edges by adding a new labelled edge and a new vertex (sometimes two new edges and vertices), there is a permutational representation of the corresponding group. Group elements correspond to integer nsequences and the nodes in the path generate all n! permutations. The extra node has a more complicated action, adding a certain quantity to some of the numbers.
likelihood and the role of models in molecular phylogenetics.
 Mol. Biol. Evol.
, 2000
"... Methods such as maximum parsimony (MP) are frequently criticized as being statistically unsound and not being based on any ''model.'' On the other hand, advocates of MP claim that maximum likelihood (ML) has some fundamental problems. Here, we explore the connection between the ..."
Abstract

Cited by 70 (11 self)
 Add to MetaCart
in general statistical settings where D depends on both continuous (nuisance) parameters and a discrete parameter x of interest. In this situation, there may be one ''unlikely'' value of that, for x ϭ x 1 , gives a higher P(D ͦ x, ) value that max P(D ͦ x 2 , ), yet for most &apos
The Search for Simple Symmetric Venn Diagrams
"... Many people are surprised to learn that Venn diagrams can be drawn to represent all of the intersections of more than three sets. This surprise is perfectly understandable since small Venn diagrams are often drawn with circles, and it is impossible to draw a Venn diagram with circles that will repre ..."
Abstract

Cited by 9 (2 self)
 Add to MetaCart
Figure 1(c) hasthree points where all three curves intersect. The regions in the diagramsof Figure 2 are colored according to rank. The traditional threecircle Venn diagramhas an appealing 3fold rotational symmetry, and it is natural to ask whether there arenVenn diagramswith ann
Abstract Cosmological Black Holes as Models of Cosmological Inhomogeneities
, 2006
"... Since cosmological black holes modify the density and pressure of the surrounding universe, and introduce heat conduction, they produce simple models of cosmological inhomogeneities that can be used to study the eect of inhomogeneities on the universe's expansion. In this thesis, new cosmologi ..."
Abstract
 Add to MetaCart
Since cosmological black holes modify the density and pressure of the surrounding universe, and introduce heat conduction, they produce simple models of cosmological inhomogeneities that can be used to study the eect of inhomogeneities on the universe's expansion. In this thesis, new cosmological black hole solutions are obtained by generalizing the expanding KerrSchild cosmological black holes to obtain the charged case, by performing a KerrSchild transformation of the Einsteinde Sitter universe (instead of a closed universe) to obtain nonexpanding KerrSchild cosmological black holes in asymptotically
at universes, and by performing a conformal transformation on isotropic black hole spacetimes to obtain isotropic cosmological black hole spacetimes. The latter approach is found to produce cosmological black holes with energymomentum tensors that are physical throughout spacetime, unlike previous solutions for cosmological black holes, which violate the energy conditions in some region of spacetime. In addition, it is demonstrated that radiationdominated and matterdominated Einsteinde Sitter universes can be directly matched across a hypersurface of constant time, and this is used to generate the rst solutions for primordial black holes that evolve from being in radiationdominated background universes to matterdominated background universes. Finally, the Weyl curvature, volume expansion, velocity eld, shear, and acceleration are calculated for the cosii mological black holes. Since the nonisotropic black holes introduce shear, according to Raychaudhuri's equation they will tend to decrease the volume expansion of the universe. Unlike several studies that have suggested the relativistic backreaction of inhomogeneities would lead to an accelerating expansion of the universe, it is concluded that shear should be the most likely in
uence of inhomogeneities, so they should most likely decrease the universe's expansion. iii
0 QUANTITATIVE UNIFORM IN TIME CHAOS PROPAGATION FOR BOLTZMANN COLLISION PROCESSES
, 2010
"... ar ..."
Noisy sorting without resampling
 In SODA ’08: Proceedings of the 19th ACMSIAM Symposium on Discrete algorithms
, 2008
"... In this paper we study noisy sorting without resampling. In this problem there is an unknown order aπ(1) <... < aπ(n) where π is a permutation on n elements. The input is the status of () n 2 queries of the form q(ai, xj), where q(ai, aj) = + with probability at least 1/2 + γ if π(i)> π(j ..."
Abstract

Cited by 42 (1 self)
 Add to MetaCart
of pairs σ(i)> σ(j) where q(σ(i), σ(j)) = −. The problem so defined is the feedback arc set problem on distributions of inputs, each of which is a tournament obtained as a noisy perturbations of a linear order. Note that when γ < 1/2 and n is large, it is impossible to recover the original order π
permission. Structured Codes in Information Theory: MIMO and Network Applications
"... All rights reserved. ..."
Cultural Biases in Economic Exchange",
, 2004
"... Abstract How much do cultural biases affect economic exchange? We try to answer this question by using the relative trust European citizens have for citizens of other countries. First, we document that this trust is affected not only by objective characteristics of the country being trusted, but al ..."
Abstract

Cited by 57 (4 self)
 Add to MetaCart
by this trade opportunity is V h > 0 (with probability p) or V l < 0 (with probability 1 − p). After the cost c is paid, 6 the value V i becomes known (to both parties) with certainty. Thus, if the value is found to be V l < 0, the trade opportunity will not be pursued. If both parties behave properly
Results 1  10
of
144