1,596 research outputs found

    THE PROBLEM OF INTERPRETATION OF PHYLOGENETIC TREES

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    Abstract. Phylogenetic algorithms have been used in a number of papers to describe the evolution of language families. In the paper the neighbor joining algorithm apply to the database of the Automated Similarity Judgment Program and results are compared with the common languages classification. A number of families have been considered in detail: North Caucasian languages, Turkic languages, Maya. In addition to recognized families, a hypothetical Nostratic macrofamily is also considered. When applying phylogenetic algorithms to databases, some errors occur. Possible causes of mistakes are analyzed, and a statement that mistakes are inevitable for phylogenetic algorithms is justified. The following main types of errors are identified. Languages in databases are represented as vectors of large dimension, while in the form of trees it is a one-dimensional structure. With decreasing dimension, the loss of information is mathematically unavoidable. Testing of one of the most popular phylogenetic algorithms – the algorithm of the neighbor joining – has been carried out, and it is shown that it gives an error in 13% of cases. Another source of error is the instability of phylogenetic algorithms – small (random) changes in the data can lead to a significant rearrangement of trees. A few recommendations on the methods of correct interpretation of results obtained via phylogenetic algorithms are proposed.Keywords: Phylogenetic Algorithm, Evolution Trees, ASJP Database, North-Caucasian languages, TurkicLanguages

    Knowledge-Driven Event Extraction in Russian: Corpus-Based Linguistic Resources

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    Automatic event extraction form text is an important step in knowledge acquisition and knowledge base population. Manual work in development of extraction system is indispensable either in corpus annotation or in vocabularies and pattern creation for a knowledge-based system. Recent works have been focused on adaptation of existing system (for extraction from English texts) to new domains. Event extraction in other languages was not studied due to the lack of resources and algorithms necessary for natural language processing. In this paper we define a set of linguistic resources that are necessary in development of a knowledge-based event extraction system in Russian: a vocabulary of subordination models, a vocabulary of event triggers, and a vocabulary of Frame Elements that are basic building blocks for semantic patterns. We propose a set of methods for creation of such vocabularies in Russian and other languages using Google Books NGram Corpus. The methods are evaluated in development of event extraction system for Russian

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

    Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

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    The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured
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