702 research outputs found
The role of psychometrics in individual differences research in cognition: A case study of the AX-CPT
Investigating individual differences in cognition requires addressing questions not often thought about in standard experimental designs, especially regarding the psychometric properties of the task. Using the AX-CPT cognitive control task as a case study example, we address four concerns that one may encounter when researching the topic of individual differences in cognition. First, we demonstrate the importance of variability in task scores, which in turn directly impacts reliability, particularly when comparing correlations in different populations. Second, we demonstrate the importance of variability and reliability for evaluating potential failures to replicate predicted correlations, even within the same population. Third, we demonstrate how researchers can turn to evaluating psychometric properties as a way of evaluating the feasibility of utilizing the task in new settings (e.g., online administration). Lastly, we show how the examination of psychometric properties can help researchers make informed decisions when designing a study, such as determining the appropriate number of trials for a task
Frustration driven structural distortion in VOMoO4
Nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR),
magnetization measurements and electronic structure calculations in VOMoO4 are
presented. It is found that VOMoO4 is a frustrated two-dimensional
antiferromagnet on a square lattice with competing exchange interactions along
the side J1 and the diagonal J2 of the square. From magnetization measurements
J1+J2 is estimated around 155 K, in satisfactory agreement with the values
derived from electronic structure calculations. Around 100 K a structural
distortion, possibly driven by the frustration, is evidenced. This distortion
induces significant modifications in the NMR and EPR spectra which can be
accounted for by valence fluctuations. The analysis of the spectra suggests
that the size of the domains where the lattice is distorted progressively grows
as the temperature approaches the transition to the magnetic ground state at
Tc=42 K
Corrigendum to ‘Population structure analysis provides insights into the infection biology and invasion strategies of Kretzschmaria deusta in trees’
On formal verification of arithmetic-based cryptographic primitives
Cryptographic primitives are fundamental for information security: they are
used as basic components for cryptographic protocols or public-key
cryptosystems. In many cases, their security proofs consist in showing that
they are reducible to computationally hard problems. Those reductions can be
subtle and tedious, and thus not easily checkable. On top of the proof
assistant Coq, we had implemented in previous work a toolbox for writing and
checking game-based security proofs of cryptographic primitives. In this paper
we describe its extension with number-theoretic capabilities so that it is now
possible to write and check arithmetic-based cryptographic primitives in our
toolbox. We illustrate our work by machine checking the game-based proofs of
unpredictability of the pseudo-random bit generator of Blum, Blum and Shub, and
semantic security of the public-key cryptographic scheme of Goldwasser and
Micali.Comment: 13 page
Mining State-Based Models from Proof Corpora
Interactive theorem provers have been used extensively to reason about
various software/hardware systems and mathematical theorems. The key challenge
when using an interactive prover is finding a suitable sequence of proof steps
that will lead to a successful proof requires a significant amount of human
intervention. This paper presents an automated technique that takes as input
examples of successful proofs and infers an Extended Finite State Machine as
output. This can in turn be used to generate proofs of new conjectures. Our
preliminary experiments show that the inferred models are generally accurate
(contain few false-positive sequences) and that representing existing proofs in
such a way can be very useful when guiding new ones.Comment: To Appear at Conferences on Intelligent Computer Mathematics 201
Population synthesis of radio and gamma-ray millisecond pulsars from the Galactic disk
We present results of a population synthesis of millisecond pulsars from the
Galactic disk. Excluding globular clusters, we model the spatial distribution
of millisecond pulsars by assuming their birth in the Galactic disk with a
random kick velocity and evolve them to the present within the Galactic
potential. We assume that normal and millisecond pulsars are standard candles
described with a common radio luminosity model that invokes a new relationship
between radio core and cone emission suggested by recent studies. In modeling
the radio emission beams, we explore the relativistic effects of time delay,
aberration and sweepback of the open field lines. While these effects are
essential in understanding pulse profiles, the phase-averaged flux is
adequately described without a relativistic model. We use a polar cap
acceleration model for the gamma-ray emission. We present the preliminary
results of our recent study and the implications for observing millisecond
pulsars with GLAST and AGILE.Comment: 38 pages, 10 figures, accepted in ApJ - new versio
Development of SSR markers and assessment of polymorphism by High Resolution Melting Analysis in populations of chestnut nut rot agent Gnomoniopsis castanea
Bottomâup effects of soil quality on a coffee arthropod interaction web
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117198/1/ecs213000721.pd
Formalization of the Lindemann-Weierstrass Theorem
International audienceThis article details a formalization in Coq of the Lindemann-Weierstrass theorem which gives a transcendence criterion for complex numbers: this theorem establishes a link between the linear independence of a set of algebraic numbers and the algebraic independence of the exponentials of these numbers. As we follow Baker's proof, we discuss the difficulties of its formalization and explain how we resolved them in Coq. Most of these difficulties revolve around multivariate polynomials and their relationship with the conjugates of a univariate polynomial. Their study ultimately leads to alternative forms of the fundamental theorem of symmetric polynomials. This formalization uses mainly the Mathcomp library for the part relying on algebra, and the Coquelicot library and the Coq standard library of real numbers for the calculus part
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