1,197 research outputs found
Unified functional network and nonlinear time series analysis for complex systems science: The pyunicorn package
We introduce the \texttt{pyunicorn} (Pythonic unified complex network and
recurrence analysis toolbox) open source software package for applying and
combining modern methods of data analysis and modeling from complex network
theory and nonlinear time series analysis. \texttt{pyunicorn} is a fully
object-oriented and easily parallelizable package written in the language
Python. It allows for the construction of functional networks such as climate
networks in climatology or functional brain networks in neuroscience
representing the structure of statistical interrelationships in large data sets
of time series and, subsequently, investigating this structure using advanced
methods of complex network theory such as measures and models for spatial
networks, networks of interacting networks, node-weighted statistics or network
surrogates. Additionally, \texttt{pyunicorn} provides insights into the
nonlinear dynamics of complex systems as recorded in uni- and multivariate time
series from a non-traditional perspective by means of recurrence quantification
analysis (RQA), recurrence networks, visibility graphs and construction of
surrogate time series. The range of possible applications of the library is
outlined, drawing on several examples mainly from the field of climatology.Comment: 28 pages, 17 figure
Protocol-based verification of message-passing parallel programs
Β© 2015 ACM.We present ParTypes, a type-based methodology for the verification of Message Passing Interface (MPI) programs written in the C programming language. The aim is to statically verify programs against protocol specifications, enforcing properties such as fidelity and absence of deadlocks. We develop a protocol language based on a dependent type system for message-passing parallel programs, which includes various communication operators, such as point-to-point messages, broadcast, reduce, array scatter and gather. For the verification of a program against a given protocol, the protocol is first translated into a representation read by VCC, a software verifier for C. We successfully verified several MPI programs in a running time that is independent of the number of processes or other input parameters. This contrasts with alternative techniques, notably model checking and runtime verification, that suffer from the state-explosion problem or that otherwise depend on parameters to the program itself. We experimentally evaluated our approach against state-of-the-art tools for MPI to conclude that our approach offers a scalable solution
Statistical Mechanics of Surjective Cellular Automata
Reversible cellular automata are seen as microscopic physical models, and
their states of macroscopic equilibrium are described using invariant
probability measures. We establish a connection between the invariance of Gibbs
measures and the conservation of additive quantities in surjective cellular
automata. Namely, we show that the simplex of shift-invariant Gibbs measures
associated to a Hamiltonian is invariant under a surjective cellular automaton
if and only if the cellular automaton conserves the Hamiltonian. A special case
is the (well-known) invariance of the uniform Bernoulli measure under
surjective cellular automata, which corresponds to the conservation of the
trivial Hamiltonian. As an application, we obtain results indicating the lack
of (non-trivial) Gibbs or Markov invariant measures for "sufficiently chaotic"
cellular automata. We discuss the relevance of the randomization property of
algebraic cellular automata to the problem of approach to macroscopic
equilibrium, and pose several open questions.
As an aside, a shift-invariant pre-image of a Gibbs measure under a
pre-injective factor map between shifts of finite type turns out to be always a
Gibbs measure. We provide a sufficient condition under which the image of a
Gibbs measure under a pre-injective factor map is not a Gibbs measure. We point
out a potential application of pre-injective factor maps as a tool in the study
of phase transitions in statistical mechanical models.Comment: 50 pages, 7 figure
Π€Π΅Π½ΠΎΠΌΠ΅Π½ ΡΠΈΠ½ΠΊΡΠ΅ΡΠΈΠ·ΠΌΠ° Π² ΡΠΊΡΠ°ΠΈΠ½ΡΠΊΠΎΠΉ Π»ΠΈΠ½Π³Π²ΠΈΡΡΠΈΠΊΠ΅
Π£ ΡΡΡΠ°ΡΠ½ΡΠΉ Π»ΡΠ½Π³Π²ΡΡΡΠΈΡΡ Π²ΠΈΠ²ΡΠ΅Π½Π½Ρ ΡΠΊΠ»Π°Π΄Π½ΠΈΡ
ΡΠΈΡΡΠ΅ΠΌΠ½ΠΈΡ
Π·Π²βΡΠ·ΠΊΡΠ² ΡΠ° Π΄ΠΈΠ½Π°ΠΌΡΠ·ΠΌΡ ΠΌΠΎΠ²ΠΈ Π½Π°Π²ΡΡΠ΄ ΡΠΈ Π±ΡΠ΄Π΅ Π·Π°Π²Π΅ΡΡΠ΅Π½ΠΈΠΌ Π±Π΅Π· ΡΡΠ°Ρ
ΡΠ²Π°Π½Π½Ρ ΡΠΈΠ½ΠΊΡΠ΅ΡΠΈΠ·ΠΌΡ. Π’ΡΠ°Π΄ΠΈΡΡΠΉΠ½ΠΎ ΡΠ²ΠΈΡΠ° ΡΡΠ°Π½Π·ΠΈΡΠΈΠ²Π½ΠΎΡΡΡ ΡΡΠ°ΠΊΡΡΡΡΡΡΡ ΡΠΊ ΠΏΠΎΡΠ΄Π½Π°Π½Π½Ρ ΡΡΠ·Π½ΠΈΡ
ΡΠΈΠΏΡΠ² ΡΡΠ²ΠΎΡΠ΅Π½Ρ ΡΠΊ ΡΠ΅Π·ΡΠ»ΡΡΠ°Ρ ΠΏΡΠΎΡΠ΅ΡΡΠ² ΡΡΠ°Π½ΡΡΠΎΡΠΌΠ°ΡΡΡ Π°Π±ΠΎ Π²ΡΠ΄ΠΎΠ±ΡΠ°ΠΆΠ΅Π½Π½Ρ ΠΏΡΠΎΠΌΡΠΆΠ½ΠΈΡ
, ΡΠΈΠ½ΠΊΡΠ΅ΡΠΈΡΠ½ΠΈΡ
ΡΠ°ΠΊΡΡΠ², ΡΠΎ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΠ·ΡΡΡΡ ΠΌΠΎΠ²Π½Ρ ΡΠΈΡΡΠ΅ΠΌΡ Π² ΡΠΈΠ½Ρ
ΡΠΎΠ½Π½ΠΎΠΌΡ Π°ΡΠΏΠ΅ΠΊΡΡ.In modern linguistics, the study of complex systemic relations and language dynamism is unlikely to be complete without considering the transitivity. Traditionally, transitivity phenomena are treated as a combination of different types of entities, formed as a result of the transformation processes or the reflection of the intermediate, syncretic facts that characterize the language system in the synchronous aspect.Π ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠΉ Π»ΠΈΠ½Π³Π²ΠΈΡΡΠΈΠΊΠ΅ ΠΈΠ·ΡΡΠ΅Π½ΠΈΠ΅ ΡΠ»ΠΎΠΆΠ½ΡΡ
ΡΠΈΡΡΠ΅ΠΌΠ½ΡΡ
ΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΠΉ ΠΈ ΡΠ·ΡΠΊΠΎΠ²ΠΎΠ³ΠΎ Π΄ΠΈΠ½Π°ΠΌΠΈΠ·ΠΌΠ° Π²ΡΡΠ΄ Π»ΠΈ Π±ΡΠ΄Π΅Ρ ΠΏΠΎΠ»Π½ΡΠΌ Π±Π΅Π· ΡΡΠ΅ΡΠ° ΡΠΈΠ½ΠΊΡΠ΅ΡΠΈΠ·ΠΌΠ°. Π’ΡΠ°Π΄ΠΈΡΠΈΠΎΠ½Π½ΠΎ ΡΠ²Π»Π΅Π½ΠΈΡ ΡΡΠ°Π½Π·ΠΈΡΠΈΠ²Π½ΠΎΡΡΠΈ ΡΡΠ°ΠΊΡΡΡΡΡΡ ΠΊΠ°ΠΊ ΡΠΎΠ²ΠΎΠΊΡΠΏΠ½ΠΎΡΡΡ ΡΠ°Π·Π»ΠΈΡΠ½ΡΡ
ΡΠΈΠΏΠΎΠ² ΡΡΡΠ½ΠΎΡΡΠ΅ΠΉ, ΡΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
Π² ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠ΅ ΠΏΡΠΎΡΠ΅ΡΡΠΎΠ² ΠΏΡΠ΅ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΡ ΠΈΠ»ΠΈ ΠΎΡΡΠ°ΠΆΠ΅Π½ΠΈΡ ΠΏΡΠΎΠΌΠ΅ΠΆΡΡΠΎΡΠ½ΡΡ
ΡΠΈΠ½ΠΊΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ°ΠΊΡΠΎΠ², ΠΊΠΎΡΠΎΡΡΠ΅ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΠ·ΡΡΡ ΡΠ·ΡΠΊΠΎΠ²ΡΡ ΡΠΈΡΡΠ΅ΠΌΡ Π² ΡΠΈΠ½Ρ
ΡΠΎΠ½Π½ΠΎΠΌ Π°ΡΠΏΠ΅ΠΊΡΠ΅
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