260,756 research outputs found
A Continuation Multilevel Monte Carlo algorithm
We propose a novel Continuation Multi Level Monte Carlo (CMLMC) algorithm for
weak approximation of stochastic models. The CMLMC algorithm solves the given
approximation problem for a sequence of decreasing tolerances, ending when the
required error tolerance is satisfied. CMLMC assumes discretization hierarchies
that are defined a priori for each level and are geometrically refined across
levels. The actual choice of computational work across levels is based on
parametric models for the average cost per sample and the corresponding weak
and strong errors. These parameters are calibrated using Bayesian estimation,
taking particular notice of the deepest levels of the discretization hierarchy,
where only few realizations are available to produce the estimates. The
resulting CMLMC estimator exhibits a non-trivial splitting between bias and
statistical contributions. We also show the asymptotic normality of the
statistical error in the MLMC estimator and justify in this way our error
estimate that allows prescribing both required accuracy and confidence in the
final result. Numerical results substantiate the above results and illustrate
the corresponding computational savings in examples that are described in terms
of differential equations either driven by random measures or with random
coefficients
A Continuation Method for Nash Equilibria in Structured Games
Structured game representations have recently attracted interest as models
for multi-agent artificial intelligence scenarios, with rational behavior most
commonly characterized by Nash equilibria. This paper presents efficient, exact
algorithms for computing Nash equilibria in structured game representations,
including both graphical games and multi-agent influence diagrams (MAIDs). The
algorithms are derived from a continuation method for normal-form and
extensive-form games due to Govindan and Wilson; they follow a trajectory
through a space of perturbed games and their equilibria, exploiting game
structure through fast computation of the Jacobian of the payoff function. They
are theoretically guaranteed to find at least one equilibrium of the game, and
may find more. Our approach provides the first efficient algorithm for
computing exact equilibria in graphical games with arbitrary topology, and the
first algorithm to exploit fine-grained structural properties of MAIDs.
Experimental results are presented demonstrating the effectiveness of the
algorithms and comparing them to predecessors. The running time of the
graphical game algorithm is similar to, and often better than, the running time
of previous approximate algorithms. The algorithm for MAIDs can effectively
solve games that are much larger than those solvable by previous methods
A continuation semantics of interrogatives that accounts for Baker's ambiguity
Wh-phrases in English can appear both raised and in-situ. However, only
in-situ wh-phrases can take semantic scope beyond the immediately enclosing
clause. I present a denotational semantics of interrogatives that naturally
accounts for these two properties. It neither invokes movement or economy, nor
posits lexical ambiguity between raised and in-situ occurrences of the same
wh-phrase. My analysis is based on the concept of continuations. It uses a
novel type system for higher-order continuations to handle wide-scope
wh-phrases while remaining strictly compositional. This treatment sheds light
on the combinatorics of interrogatives as well as other kinds of so-called
A'-movement.Comment: 20 pages; typo fixe
Fake news. A continuation or rejection of the traditional news paradigm?
In the article, I analysed the problem of fake news in the context of the traditional paradigm of a news story. The traditional paradigm posits that, most of all, a piece of information is true. However in contemporary media, there exist pieces of information which are fabricated and untrue. It is not a new phenomenon, yet it has intensified in recent years. News stories are fabricated for entertainment, political, or commercial purposes. They are carriers of propaganda and profit. The essence of fake news is the intentional misleading of the receiver for achieving the above gains. It is difficult to verify their veracity, and identify fake news items due to their similarity to real pieces of news. That is why they are becoming a part of the media landscape in which we will probably have to exist
Letter from Julia to Marie August 17, 1943
This is a continuation or very long postscript to the letter from August 1
A continuation principle for a class of periodically perturbed autonomous systems
In this paper we evaluate the topological index of periodic solutions otained
via the Malkin-Loud bifurcation result. Incidentally, we do not assume that the
perturbation is differentiale.Comment: Accepted to Math. Nachr., Vol. 281, (2008), No.
Spirituality, Economics, and Education A Dialogic Critique of Spiritual Capital
This paper consists of a conversation between a philosopher specialising in ethics and religion and an educational researcher with an interest in cultural studies and contemporary social theory. Dialogic in form, this paper employs an interdisciplinary response to an interdisciplinary project and offers the following components: a dialogic theorizing of the implications for education of a research project on spiritual capital; a continuation of the project of analyzing moral thinking in various cultural and societal settings; a continuation of the project of analyzing political rhetoric (towards an understanding of the polemics of political rhetoric); a reaffirmation of the value of recognizing difference and ambiguity in the global moment
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