222 research outputs found
Stable manifolds for holomorphic automorphisms
We give a sufficient condition for the abstract basin of attraction of a sequence of holomorphic self-maps of balls in ℂd to be biholomorphic to ℂd. As a consequence, we get a sufficient condition for the stable manifold of a point in a compact hyperbolic invariant subset of a complex manifold to be biholomorphic to a complex Euclidean space. Our result immediately implies previous theorems obtained by Jonsson–Varolin and by Peters; in particular, we prove (without using Oseledec's theory) that the stable manifold of any point where the negative Lyapunov exponents are well-defined is biholomorphic to a complex Euclidean space. Our approach is based on the solution of a linear control problem in spaces of subexponential sequences, and on careful estimates of the norm of the conjugacy operator by a lower triangular matrix on the space of k-homogeneous polynomial endomorphisms of ℂd
An On-the-fly Tableau-based Decision Procedure for PDL-Satisfiability
We present a tableau-based algorithm for deciding satisfiability for
propositional dynamic logic (PDL) which builds a finite rooted tree with
ancestor loops and passes extra information from children to parents to
separate good loops from bad loops during backtracking. It is easy to
implement, with potential for parallelisation, because it constructs a
pseudo-model ``on the fly'' by exploring each tableau branch independently. But
its worst-case behaviour is 2EXPTIME rather than EXPTIME. A prototype
implementation in the TWB (http://twb.rsise.anu.edu.au) is available.Comment: 26 pages, longer version of article in Methods for Modalities 2007;
improved readability of proof
Strong Dependencies between Software Components
Component-based systems often describe context requirements in terms of
explicit inter-component dependencies. Studying large instances of such
systems?such as free and open source software (FOSS) distributions?in terms of
declared dependencies between packages is appealing. It is however also
misleading when the language to express dependencies is as expressive as
boolean formulae, which is often the case. In such settings, a more appropriate
notion of component dependency exists: strong dependency. This paper introduces
such notion as a first step towards modeling semantic, rather then syntactic,
inter-component relationships. Furthermore, a notion of component sensitivity
is derived from strong dependencies, with ap- plications to quality assurance
and to the evaluation of upgrade risks. An empirical study of strong
dependencies and sensitivity is presented, in the context of one of the
largest, freely available, component-based system
The Software Heritage Graph Dataset: Large-scale Analysis of Public Software Development History
International audienceSoftware Heritage is the largest existing public archive of software source code and accompanying development history. It spans more than five billion unique source code files and one billion unique commits , coming from more than 80 million software projects. These software artifacts were retrieved from major collaborative development platforms (e.g., GitHub, GitLab) and package repositories (e.g., PyPI, Debian, NPM), and stored in a uniform representation linking together source code files, directories, commits, and full snapshots of version control systems (VCS) repositories as observed by Software Heritage during periodic crawls. This dataset is unique in terms of accessibility and scale, and allows to explore a number of research questions on the long tail of public software development, instead of solely focusing on "most starred" repositories as it often happens
Expression of AP-2a, AP-2g and ESDN in primary melanomas: Correlation with histopathological features and potential prognostic value
Circulating CD4+ CD25brightFOXP3+ regulatory T-cells are significantly reduced in bullous pemphigoid patients.
Using Preferences to Tame your Package Manager
International audienceDetermining whether some components can be installed on a system is a complex problem: not only it is NP-complete in the worst case, but there can also be exponentially many solutions to it. Ordinary package managers use ad-hoc heuristics to solve this installation problem and choose a particular solution, making extremely difficult to change or sidestep these heuristics when the result is not the one we expect. When software repositories become complex enough, one gets vastly superior results by delegating dependency handling to a specialised solver, and use optimisation functions (or preferences) to control the class of solutions that are found. The opam package manager relies on the CUDF pivot format, which allows OCaml users that have a CUDF-compliant solver on their machine to reap the benefits of preferences-based dependency resolution. Thanks to the solver farm provided by Irill, these benefits are now extended to the OCaml community at large. In this talk we will present the preferences language and explain how to use it
Relevance of multiple basin drainage and primary histologic regression in prognosis of trunk melanoma patients with negative sentinel lymph nodes.
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