191,238 research outputs found
Deux indicateurs probabilistes de retournement cyclique pour l’économie française.
This paper proposes two new coincident probabilistic cyclical indicators developed by the Bank of France in order to follow, on a monthly basis, the French economic activity. The first one is an indicator which aims at detecting the turning points of the acceleration cycle while the second one is dedicated to the follow-up of recession phases in the industrial sector. Both indicators are based on the methodology of Markov-Switching models and use only for input the Bank of France monthly business survey. An historical validation since 1998 points out to the interest and the complementarity of both indicators for the short-term economic diagnosis. This kind of indicators provides with an original and additional conjonctural qualitative information by comparison with more classical quantitative tools aiming at estimating the GDP growth rate.Business cycle ; Acceleration cycle ; Probabilistic indicator ; Markov-Switching models ; Surveys.
Logic, Probability and Action: A Situation Calculus Perspective
The unification of logic and probability is a long-standing concern in AI,
and more generally, in the philosophy of science. In essence, logic provides an
easy way to specify properties that must hold in every possible world, and
probability allows us to further quantify the weight and ratio of the worlds
that must satisfy a property. To that end, numerous developments have been
undertaken, culminating in proposals such as probabilistic relational models.
While this progress has been notable, a general-purpose first-order knowledge
representation language to reason about probabilities and dynamics, including
in continuous settings, is still to emerge. In this paper, we survey recent
results pertaining to the integration of logic, probability and actions in the
situation calculus, which is arguably one of the oldest and most well-known
formalisms. We then explore reduction theorems and programming interfaces for
the language. These results are motivated in the context of cognitive robotics
(as envisioned by Reiter and his colleagues) for the sake of concreteness.
Overall, the advantage of proving results for such a general language is that
it becomes possible to adapt them to any special-purpose fragment, including
but not limited to popular probabilistic relational models
Semantics, Modelling, and the Problem of Representation of Meaning -- a Brief Survey of Recent Literature
Over the past 50 years many have debated what representation should be used
to capture the meaning of natural language utterances. Recently new needs of
such representations have been raised in research. Here I survey some of the
interesting representations suggested to answer for these new needs.Comment: 15 pages, no figure
Duplicate Detection in Probabilistic Data
Collected data often contains uncertainties. Probabilistic databases have been proposed to manage uncertain data. To combine data from multiple autonomous probabilistic databases, an integration of probabilistic data has to be performed. Until now, however, data integration approaches have focused on the integration of certain source data (relational or XML). There is no work on the integration of uncertain (esp. probabilistic) source data so far. In this paper, we present a first step towards a concise consolidation of probabilistic data. We focus on duplicate detection as a representative and essential step in an integration process. We present techniques for identifying multiple probabilistic representations of the same real-world entities. Furthermore, for increasing the efficiency of the duplicate detection process we introduce search space reduction methods adapted to probabilistic data
Automatic differentiation in machine learning: a survey
Derivatives, mostly in the form of gradients and Hessians, are ubiquitous in
machine learning. Automatic differentiation (AD), also called algorithmic
differentiation or simply "autodiff", is a family of techniques similar to but
more general than backpropagation for efficiently and accurately evaluating
derivatives of numeric functions expressed as computer programs. AD is a small
but established field with applications in areas including computational fluid
dynamics, atmospheric sciences, and engineering design optimization. Until very
recently, the fields of machine learning and AD have largely been unaware of
each other and, in some cases, have independently discovered each other's
results. Despite its relevance, general-purpose AD has been missing from the
machine learning toolbox, a situation slowly changing with its ongoing adoption
under the names "dynamic computational graphs" and "differentiable
programming". We survey the intersection of AD and machine learning, cover
applications where AD has direct relevance, and address the main implementation
techniques. By precisely defining the main differentiation techniques and their
interrelationships, we aim to bring clarity to the usage of the terms
"autodiff", "automatic differentiation", and "symbolic differentiation" as
these are encountered more and more in machine learning settings.Comment: 43 pages, 5 figure
Probabilistic Programming Concepts
A multitude of different probabilistic programming languages exists today,
all extending a traditional programming language with primitives to support
modeling of complex, structured probability distributions. Each of these
languages employs its own probabilistic primitives, and comes with a particular
syntax, semantics and inference procedure. This makes it hard to understand the
underlying programming concepts and appreciate the differences between the
different languages. To obtain a better understanding of probabilistic
programming, we identify a number of core programming concepts underlying the
primitives used by various probabilistic languages, discuss the execution
mechanisms that they require and use these to position state-of-the-art
probabilistic languages and their implementation. While doing so, we focus on
probabilistic extensions of logic programming languages such as Prolog, which
have been developed since more than 20 years
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