9,745 research outputs found
Comparing linguistic judgments and corpus frequencies as windows on grammatical competence: A study of argument linearization in German clauses
We present an overview of several corpus studies we carried out into the frequencies of argument NP orderings in the midfield of subordinate and main clauses of German. Comparing the corpus frequencies with grammaticality ratings published by Keller’s (2000), we observe a “grammaticality–frequency gap”: Quite a few argument orderings with zero corpus frequency are nevertheless assigned medium–range grammaticality ratings. We propose an explanation in terms of a two-factor theory. First, we hypothesize that the grammatical induction component needs a sufficient number of exposures to a syntactic pattern to incorporate it into its repertoire of more or less stable rules of grammar. Moderately to highly frequent argument NP orderings are likely have attained this status, but not their zero-frequency counterparts. This is why the latter argument sequences cannot be produced by the grammatical encoder and are absent from the corpora. Secondly, we assumed that an extraneous (nonlinguistic) judgment process biases the ratings of moderately grammatical linear order patterns: Confronted with such structures, the informants produce their own “ideal delivery” variant of the to-be-rated target sentence and evaluate the similarity between the two versions. A high similarity score yielded by this judgment then exerts a positive bias on the grammaticality rating—a score that should not be mistaken for an authentic grammaticality rating. We conclude that, at least in the linearization domain studied here, the goal of gaining a clear view of the internal grammar of language users is best served by a combined strategy in which grammar rules are founded on structures that elicit moderate to high grammaticality ratings and attain at least moderate usage frequencies
Low-mass Star Formation: Observations
I briefly review recent observations of regions forming low mass stars. The
discussion is cast in the form of seven questions that have been partially
answered, or at least illuminated, by new data. These are the following: where
do stars form in molecular clouds; what determines the IMF; how long do the
steps of the process take; how efficient is star formation; do any theories
explain the data; how are the star and disk built over time; and what chemical
changes accompany star and planet formation. I close with a summary and list of
open questions.Comment: Proceedings of Computational Star Formation Conference, Barcelon
Differences in physical-fitness test scores between actively and passively recruited older adults: consequences for norm-based classification
This study investigated differences in physical-fitness test scores between actively and passively recruited older adults and the consequences thereof for norm-based classification of individuals. Walking endurance, grip strength, hip flexibility, balance, manual dexterity, and reaction time were measured in participants age 57 years or older: 1 sample recruited through media announcements (passively recruited) and 1 sample recruited through personal contact (actively recruited). Classifications on a 5-point scale based on norms were cross-tabulated. Compared with the actively recruited sample, performance of the passively recruited sample was significantly better on all tests except, for women, hip flexibility and manual dexterity. Cross-tabulation of the 2 classifications showed that percentages of agreement varied from 27.4% to 87.4%. Cohen's Kappa varied from. 11 to .84. Caution should be used when giving feedback on test performance and subsequently making physical activity recommendations if norms are based on the performance of passively recruited older adults
A generation-oriented workbench for performance grammar: Capturing linear order variability in German and Dutch
We describe a generation-oriented workbench for the Performance Grammar (PG) formalism, highlighting the treatment of certain word order and movement constraints in Dutch and German. PG enables a simple and uniform treatment of a heterogeneous collection of linear order phenomena in the domain of verb constructions (variably known as Cross-serial Dependencies, Verb Raising, Clause Union, Extraposition, Third Construction, Particle Hopping, etc.). The central data structures enabling this feature are clausal “topologies”: one-dimensional arrays associated with clauses, whose cells (“slots”) provide landing sites for the constituents of the clause. Movement operations are enabled by unification of lateral slots of topologies at adjacent levels of the clause hierarchy. The PGW generator assists the grammar developer in testing whether the implemented syntactic knowledge allows all and only the well-formed permutations of constituents
A generation-oriented workbench for performance grammar: Capturing linear order variability in German and Dutch
We describe a generation-oriented workbench for the Performance Grammar (PG) formalism, highlighting the treatment of certain word order and movement constraints in Dutch and German. PG enables a simple and uniform treatment of a heterogeneous collection of linear order phenomena in the domain of verb constructions (variably known as Cross-serial Dependencies, Verb Raising, Clause Union, Extraposition, Third Construction, Particle Hopping, etc.). The central data structures enabling this feature are clausal “topologies”: one-dimensional arrays associated with clauses, whose cells (“slots”) provide landing sites for the constituents of the clause. Movement operations are enabled by unification of lateral slots of topologies at adjacent levels of the clause hierarchy. The PGW generator assists the grammar developer in testing whether the implemented syntactic knowledge allows all and only the well-formed permutations of constituents
Performance evaluation of the Mojette erasure code for fault-tolerant distributed hot data storage
Packet erasure codes are today a real alternative to replication in fault
tolerant distributed storage systems. In this paper, we propose the Mojette
erasure code based on the Mojette transform, a formerly tomographic tool. The
performance of coding and decoding are compared to the Reed-Solomon code
implementations of the two open-source reference libraries namely ISA-L and
Jerasure 2.0. Results clearly show better performances for our discrete
geometric code compared to the classical algebraic approaches. A gain factor up
to is measured in comparison with the ISA-L Intel . Those very good
performances allow to deploy Mojette erasure code for hot data distributed
storage and I/O intensive applications.Comment: 5 page
Sub-arcsecond SMA observations of the prototype Class 0 object VLA1623 at 1.3 mm: A single protostar with a structured outflow cavity ?
We present 1.3-mm subarcsecond SMA observations of the prototypical Class 0
protostar VLA1623. We report the detection of 1.3-mm continuum emission both
from the central protostellar component VLA1623 and two additional sources,
Knot-A and Knot-B, which have been already detected at longer wavelengths.
Knot-A and Knot-B are both located along the western cavity wall opened by the
protostellar outflow from VLA1623. Our SMA observations moreover show that
these two continuum sources are associated with bright, high-velocity 12CO(2-1)
emission, slightly shifted downstream of the outflow propagation direction with
respect to the 1.3-mm continuum emission peaks. The alignment of Knot-A and
Knot-B along the protostellar outflow cavity, the compactness of their 1.3-mm
continuum emission and the properties of the associated CO emission suggest
that these two sources trace outflow features due to shocks along the cavity
wall, rather than protostellar objects. While it was considered as one of the
best examples of a close protobinary system so far, the present analysis
suggests that the prototypical Class 0, VLA1623, is single on the scales a>100
AU probed by our SMA observations. Moreover, we present here the second robust
case of compact millimeter continuum emission produced by interactions between
the protostellar jet and the envelope of a Class 0 protostar, which suggests a
high occurrence of these outflow features during the embedded phase.Comment: Accepted for publication in Astronomy and Astrophysics. Low
resolution figure
Dust, Ice, and Gas In Time (DIGIT) Herschel program first results: A full PACS-SED scan of the gas line emission in protostar DK Chamaeleontis
Aims. We aim to study the composition and energetics of the circumstellar material of DK Cha, an intermediate-mass star in transition from an
embedded configuration to a star plus disk stage, during this pivotal stage of its evolution.
Methods. Using the range scan mode of PACS on the Herschel Space Observatory, we obtained a spectrum of DK Cha from 55 to 210 μm as part
of the DIGIT key program.
Results. Almost 50 molecular and atomic lines were detected, many more than the 7 lines detected in ISO-LWS. Nearly the entire ladder of CO
from J = 14–13 to 38–37 (E_u/k = 4080 K), water from levels as excited as J_(K−1 K+1) = 7_(07) (E_u/k = 843 K), and OH lines up to E_u/k = 290 K were
detected.
Conclusions. The continuum emission in our PACS SED scan matches the flux expected by a model consisting of a star, a surrounding disk of
0.03 M_⊙, and an envelope of a similar mass, supporting the suggestion that the object is emerging from its main accretion stage. Molecular, atomic,
and ionic emission lines in the far-infrared reveal the outflow’s influence on the envelope. The inferred hot gas may be photon-heated, but some
emission may be caused by C-shocks in the walls of the outflow cavity
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