4,813 research outputs found
ON THE STRUCTURE AND ACQUISITION OF TELICITY AND UNACCUSATIVITY IN VIETNAMESE
In this paper, we investigate Chinese L2 learners' knowledge of two grammatical constraints in Vietnamese: the first, a constraint on the aspectual interpretation of accomplishment predicates, the second pertaining to alternations in the position of embedded subjects in mono-clausal lam causatives. Whereas the former constraint is shared by Vietnamese and Chinese, the two languages differ with respect to the latter. The results of three judgment tasks provide statistically reliable support for the idea that L2 interlanguage grammars are not ultimately limited by Ll patterns; given the absence of explicit teaching and only limited exposure to relevant structures, it is suggested that learners' performance may be guided by UG information
Importance Sketching of Influence Dynamics in Billion-scale Networks
The blooming availability of traces for social, biological, and communication
networks opens up unprecedented opportunities in analyzing diffusion processes
in networks. However, the sheer sizes of the nowadays networks raise serious
challenges in computational efficiency and scalability.
In this paper, we propose a new hyper-graph sketching framework for inflence
dynamics in networks. The central of our sketching framework, called SKIS, is
an efficient importance sampling algorithm that returns only non-singular
reverse cascades in the network. Comparing to previously developed sketches
like RIS and SKIM, our sketch significantly enhances estimation quality while
substantially reducing processing time and memory-footprint. Further, we
present general strategies of using SKIS to enhance existing algorithms for
influence estimation and influence maximization which are motivated by
practical applications like viral marketing. Using SKIS, we design high-quality
influence oracle for seed sets with average estimation error up to 10x times
smaller than those using RIS and 6x times smaller than SKIM. In addition, our
influence maximization using SKIS substantially improves the quality of
solutions for greedy algorithms. It achieves up to 10x times speed-up and 4x
memory reduction for the fastest RIS-based DSSA algorithm, while maintaining
the same theoretical guarantees.Comment: 12 pages, to appear in ICDM 2017 as a regular pape
The Milk Quality of Dairy Cows as Influenced by Months and Grassland Regions in the Tropical Country
The objective of the study was to evaluate the milk yield and quality of dairy cows across periods of year and grassland regions in the tropical country, Vietnam. The milk data were collected from October 2021 to March 2022 at three farms (Farm one in Gialai Province, Farm two and three in Ho Chi Minh City, Vietnam). Each Farm used the different software to manage the milk yield and quality, including SCR DataFlow II, Afifarm, and Epacific management software. The milk properties of freezing point (FP), total solid (TS), fatness, solids-not-fat (SNF), protein, and lactose were analyzed in lab. The milk somatic cell count (SCC) was examined using Foss MilkoScan analyzer. The results showed the milk yield average differed between 3 Farms (24.26, 21.15, 12.55 kg/day/cow, respectively; P \u3c 0.01). The characteristics of milk quality were FP -0.520C, TS 12.64%, fatness 3.50%, SNF 8.70%, protein 3.43%, lactose 4.64%, and SCC 737,000 cells/ml. The milk quality varied between months for all three farms (P \u3c 0.01), with quality highest on Farm one and the lowest on Farm three. The milk yield was highest in December and January at 25 and 21 kg/day/cow for Farm one and two, respectively, but it was the same milk yield during the months in Farm three. The SCC of milk decreased month by month from December 2021 to March 2022, and was lowest in March (593,000, 607,000 cells/ml on Farm 1,3, respectively, P \u3c 0.01). Our study showed a positive correlation between the grassland field, dairy cow population, and milk yield of the farms. The milk quality of dairy cows was influenced by the different grassland regions in the tropical areas
Widely separated binary systems of very low mass stars
In this paper we review some recent detections of wide binary brown dwarf
systems and discuss them in the context of the multiplicity properties of very
low-mass stars and brown dwarfs.Comment: 2 pages, 1 figure (new version with minor corrections); to appear in
the proceedings of the workshop "Ultra-low mass star formation and
evolution", to be published in A
Discovery of Radio Emission from the Tight M8 Binary: LP 349-25
We present radio observations of 8 ultracool dwarfs with a narrow spectral
type range (M8-M9.5) using the Very Large Array at 8.5 GHz. Only the tight M8
binary LP 349-25 was detected. LP 349-25 is the tenth ultracool dwarf system
detected in radio and its trigonometric parallax pi = 67.6 mas, recently
measured by Gatewood et al., makes it the furthest ultracool system detected by
the Very Large Array to date, and the most radio-luminous outside of obvious
flaring activity or variability. With a separation of only 1.8 AU, masses of
the components of LP 349-25 can be measured precisely without any theoretical
assumptions (Forveille et al.), allowing us to clarify their fully-convective
status and hence the kind of magnetic dynamo in these components which may play
an important role to explain our detection of radio emission from these
objects. This also makes LP 349-25 an excellent target for further studies with
better constraints on the correlations between X-ray, radio emission and
stellar parameters such as mass, age, temperature, and luminosity in ultracool
dwarfs.Comment: accepted by ApJ, referee's comments included, typo in equation 1
correcte
Imposition of physical parameters in dissipative particle dynamics
In the mesoscale simulations by the dissipative particle dynamics (DPD), the motion of a fluid is modelled by a set of particles interacting in a pairwise manner, and it has been shown to be governed by the NavierâStokes equation, with its physical properties, such as viscosity, Schmidt number, isothermal compressibility, relaxation and inertia time scales, in fact its whole rheology resulted from the choice of the DPD model parameters. In this work, we will explore the response of a DPD fluid with respect to its parameter space, where the model input parameters can be chosen in advance so that (i) the ratio between the relaxation and inertia time scales is fixed; (ii) the isothermal compressibility of water at room temperature is enforced; and (iii) the viscosity and Schmidt number can be specified as inputs. These impositions are possible with some extra degrees of freedom in the weighting functions for the conservative and dissipative forces. Numerical experiments show an improvement in the solution quality over conventional DPD parameters/weighting functions, particularly for the number density distribution and computed stresses
A note on dissipative particle dynamics (DPD) modelling of simple fluids
In this paper, we show that a Dissipative Particle Dynamics (DPD) model of a viscous Newtonian fluid may actually produce a linear viscoelastic fluid. We demonstrate that a single set of DPD particles can be used to model a linear viscoelastic fluid with its physical parameters, namely the dynamical viscosity and the relaxation time in its memory kernel, determined from the DPD system at equilibrium. The emphasis of this study is placed on (i) the estimation of the linear viscoelastic effect from the standard parameter choice; and (ii) the investigation of the dependence of the DPD transport properties on the length and time scales, which are introduced from the physical phenomenon under examination. Transverse-current auto-correlation functions (TCAF) in Fourier space are employed to study the effects of the length scale, while analytic expressions of the shear stress in a simple small amplitude oscillatory shear flow are utilised to study the effects of the time scale. A direct mechanism for imposing the particle diffusion time and fluid viscosity in the hydrodynamic limit on the DPD system is also proposed
SMA observations of the proto brown dwarf candidate SSTB213 J041757
Context. The previously identified source SSTB213 J041757 is a proto brown
dwarf candidate in Taurus, which has two possible components A and B. It was
found that component B is probably a class 0/I proto brown dwarf associated
with an extended envelope.
Aims. Studying molecular outflows from young brown dwarfs provides important
insight into brown dwarf formation mechanisms, particularly brown dwarfs at the
earliest stages such as class 0, I. We therefore conducted a search for
molecular outflows from SSTB213 J041757.
Methods. We observed SSTB213 J041757 with the Submillimeter Array to search
for CO molecular outflow emission from the source.
Results. Our CO maps do not show any outflow emission from the proto brown
dwarf candidate.
Conclusions. The non-detection implies that the molecular outflows from the
source are weak; deeper observations are therefore needed to probe the outflows
from the source.Comment: 7 pages, 4 figures, accepted for publication in A&
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