237 research outputs found
Mutualistic Coupling Between Vocabulary and Reasoning in Young Children: A Replication and Extension of the Study by Kievit et al. (2017).
Recent work suggests that the positive manifold of individual differences may arise, or be amplified, by a mechanism called mutualism. Kievit et al. (2017) showed that a latent change score implementation of the mutualism model outperformed alternative models, demonstrating positive reciprocal interactions between vocabulary and reasoning during development. Here, we replicated these findings in a cohort of children ( N = 227, 6-8 years old) and expanded the findings in three directions. First, a third wave of data was included, and the findings were robust to alternative model specifications. Second, a simulation demonstrated that data sets of similar magnitude and distributional properties could have, in principle, favored alternative models with close to 100% power. Third, we found support for the hypothesis that mutualistic-coupling effects are stronger and self-feedback parameters weaker in younger children. Together, these findings replicated the work of Kievit et al. (2017) and further support the hypothesis that mutualism supports cognitive development
Urnings:A new method for tracking dynamically changing parameters in paired comparison systems
We introduce a new rating system for tracking the development of parameters based on a stream of observations that can be viewed as paired comparisons. Rating systems are applied in competitive games, adaptive learning systems and platforms for product and service reviews. We model each observation as an outcome of a game of chance that depends on the parameters of interest (e.g. the outcome of a chess game depends on the abilities of the two players). Determining the probabilities of the different game outcomes is conceptualized as an urn problem, where a rating is represented by a probability (i.e. proportion of balls in the urn). This setup allows for evaluating the standard errors of the ratings and performing statistical inferences about the development of, and relations between, parameters. Theoretical properties of the system in terms of the invariant distributions of the ratings and their convergence are derived. The properties of the rating system are illustrated with simulated examples and its potential for answering research questions is illustrated using data from competitive chess, a movie review system, and an adaptive learning system for math
Tracking a multitude of abilities as they develop
Recently, the Urnings algorithm (Bolsinova et al., 2022, J. R. Stat. Soc. Ser. C Appl. Statistics, 71, 91) has been proposed that allows for tracking the development of abilities of the learners and the difficulties of the items in adaptive learning systems. It is a simple and scalable algorithm which is suited for large-scale applications in which large streams of data are coming into the system and on-the-fly updating is needed. Compared to alternatives like the Elo rating system and its extensions, the Urnings rating system allows the uncertainty of the ratings to be evaluated and accounts for adaptive item selection which, if not corrected for, may distort the ratings. In this paper we extend the Urnings algorithm to allow for both between-item and within-item multidimensionality. This allows for tracking the development of interrelated abilities both at the individual and the population level. We present formal derivations of the multidimensional Urnings algorithm, illustrate its properties in simulations, and present an application to data from an adaptive learning system for primary school mathematics called Math Garden
Urnings: A new method for tracking dynamically changing parameters in paired comparison systems
We introduce a new rating system for tracking the development of parameters based on a stream of observations. Rating systems are applied in competitive games, adaptive learning systems, and platforms for product and service ratings. We model each observation as an outcome of a game of chance that depends on the parameters of interest (e.g., the outcome of a chess game depends on the abilities of the two players). Determining the probabilities of the different game outcomes is conceptualized as an urn problem, where a rating is represented by a proportion of colored balls in an urn. This setup allows for evaluating the standard errors of the ratings and performing statistical inferences about the development of and relations between parameters. Theoretical properties of the system in terms of the invariant distributions of the ratings and their convergence are derived. The properties of the rating system are illustrated with simulated examples and its potential for answering research questions is illustrated using data from competitive chess
Thermal fission rate around super-normal phase transition
Using Langer's method, we discuss the temperature dependence of
nuclear fission width in the presence of dissipative environments. We introduce
a low cut-off frequency to the spectral density of the environmental
oscillators in order to mimic the pairing gap. It is shown that the decay width
rapidly decreases at the critical temperature, where the phase transition from
super to normal fluids takes place. Relation to the recently observed threshold
for the dissipative fission is discussed.Comment: 12 pages, Latex, Submitted to Physical Review C for publication, 3
Postscript figures are available by request from
[email protected]
Centrality Dependence of Charged Particle Multiplicity at Mid-Rapidity in Au+Au Collisions at sqrt(s_NN) = 130 GeV
We present a measurement of the pseudorapidity density of primary charged
particles near mid-rapidity in Au+Au collisions at sqrt(s_NN) = 130 GeV as a
function of the number of participating nucleons. These results are compared to
models in an attempt to discriminate between competing scenarios of particle
production in heavy ion collisions.Comment: 5 pages, 4 figures, revtex (submitted to Phys. Rev. Letters
On nuclear transport at small excitations
Numerical computations of transport coefficients at low temperatures are
presented for shapes typically encountered in nuclear fission. The influence of
quantum effects of the nucleonic degrees of freedom is examined, with pair
correlations included. Consequences for global collective motion are studied
for the case of the decay rate. The range of temperatures is specified above
which this motion may be described as a quantal diffusion process.Comment: 8 pages, LaTex, 2 postscript figures; final version with small
editorial changes, Phys. Rev. Lett. 82 (1999) 4603; e-mail:
[email protected]; [email protected]
Double-Spin Asymmetry in the Cross Section for Exclusive rho^0 Production in Lepton-Proton Scattering
Evidence for a positive longitudinal double-spin asymmetry = 0.24
+-0.11 (stat) +-0.02 (syst) in the cross section for exclusive diffractive
rho^0(770) vector meson production in polarised lepton-proton scattering was
observed by the HERMES experiment. The longitudinally polarised 27.56 GeV HERA
positron beam was scattered off a longitudinally polarised pure hydrogen gas
target. The average invariant mass of the photon-proton system has a value of
= 4.9 GeV, while the average negative squared four-momentum of the virtual
photon is = 1.7 GeV^2. The ratio of the present result to the
corresponding spin asymmetry in inclusive deep-inelastic scattering is in
agreement with an early theoretical prediction based on the generalised vector
meson dominance model.Comment: 10 pages, 4 embedded figures, LaTe
Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV
The Lambda(b) differential production cross section and the cross section
ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum
pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7
TeV using data collected by the CMS experiment at the LHC. The measurements are
based on Lambda(b) decays reconstructed in the exclusive final state J/Psi
Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and
Lambda to proton pion, using a data sample corresponding to an integrated
luminosity of 1.9 inverse femtobarns. The product of the cross section times
the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls
faster than that of b mesons. The measured value of the cross section times the
branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06
+/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for
anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are
statistical and systematic, respectively.Comment: Submitted to Physics Letters
Supplement: "Localization and broadband follow-up of the gravitational-wave transient GW150914" (2016, ApJL, 826, L13)
This Supplement provides supporting material for Abbott et al. (2016a). We briefly summarize past electromagnetic (EM) follow-up efforts as well as the organization and policy of the current EM follow-up program. We compare the four probability sky maps produced for the gravitational-wave transient GW150914, and provide additional details of the EM follow-up observations that were performed in the different bands
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