197 research outputs found
Exploring the Measurement Properties of the eHealth Literacy Scale (eHEALS) Among Baby Boomers: A Multinational Test of Measurement Invariance
BACKGROUND: The eHealth Literacy Scale (eHEALS) is one of only a few available measurement scales to assess eHealth literacy. Perhaps due to the relative paucity of such measures and the rising importance of eHealth literacy, the eHEALS is increasingly a choice for inclusion in a range of studies across different groups, cultures, and nations. However, despite its growing popularity, questions have been raised over its theoretical foundations, and the factorial validity and multigroup measurement properties of the scale are yet to be investigated fully. OBJECTIVE: The objective of our study was to examine the factorial validity and measurement invariance of the eHEALS among baby boomers (born between 1946 and 1964) in the United States, United Kingdom, and New Zealand who had used the Internet to search for health information in the last 6 months. METHODS: Online questionnaires collected data from a random sample of baby boomers from the 3 countries of interest. The theoretical underpinning to eHEALS comprises social cognitive theory and self-efficacy theory. Close scrutiny of eHEALS with analysis of these theories suggests a 3-factor structure to be worth investigating, which has never before been explored. Structural equation modeling tested a 3-factor structure based on the theoretical underpinning to eHEALS and investigated multinational measurement invariance of the eHEALS. RESULTS: We collected responses (N=996) to the questionnaires using random samples from the 3 countries. Results suggest that the eHEALS comprises a 3-factor structure with a measurement model that falls within all relevant fit indices (root mean square error of approximation, RMSEA=.041, comparative fit index, CFI=.986). Additionally, the scale demonstrates metric invariance (RMSEA=.040, CFI=.984, ΔCFI=.002) and even scalar invariance (RMSEA=.042, CFI=.978, ΔCFI=.008). CONCLUSIONS: To our knowledge, this is the first study to demonstrate multigroup factorial equivalence of the eHEALS, and did so based on data from 3 diverse nations and random samples drawn from an increasingly important cohort. The results give increased confidence to researchers using the scale in a range of eHealth assessment applications from primary care to health promotions
One Dimensional Nonequilibrium Kinetic Ising Models with Branching Annihilating Random Walk
Nonequilibrium kinetic Ising models evolving under the competing effect of
spin flips at zero temperature and nearest neighbour spin exchanges at
are investigated numerically from the point of view of a phase
transition. Branching annihilating random walk of the ferromagnetic domain
boundaries determines the steady state of the system for a range of parameters
of the model. Critical exponents obtained by simulation are found to agree,
within error, with those in Grassberger's cellular automata.Comment: 10 pages, Latex, figures upon request, SZFKI 05/9
Site-bond representation and self-duality for totalistic probabilistic cellular automata
We study the one-dimensional two-state totalistic probabilistic cellular
automata (TPCA) having an absorbing state with long-range interactions, which
can be considered as a natural extension of the Domany-Kinzel model. We
establish the conditions for existence of a site-bond representation and
self-dual property. Moreover we present an expression of a set-to-set
connectedness between two sets, a matrix expression for a condition of the
self-duality, and a convergence theorem for the TPCA.Comment: 11 pages, minor corrections, journal reference adde
Propagation and Extinction in Branching Annihilating Random Walks
We investigate the temporal evolution and spatial propagation of branching
annihilating random walks in one dimension. Depending on the branching and
annihilation rates, a few-particle initial state can evolve to a propagating
finite density wave, or extinction may occur, in which the number of particles
vanishes in the long-time limit. The number parity conserving case where
2-offspring are produced in each branching event can be solved exactly for unit
reaction probability, from which qualitative features of the transition between
propagation and extinction, as well as intriguing parity-specific effects are
elucidated. An approximate analysis is developed to treat this transition for
general BAW processes. A scaling description suggests that the critical
exponents which describe the vanishing of the particle density at the
transition are unrelated to those of conventional models, such as Reggeon Field
Theory. P. A. C. S. Numbers: 02.50.+s, 05.40.+j, 82.20.-wComment: 12 pages, plain Te
Absorption problems for quantum walks in one dimension
This paper treats absorption problems for the one-dimensional quantum walk
determined by a 2 times 2 unitary matrix U on a state space {0,1,...,N} where N
is finite or infinite by using a new path integral approach based on an
orthonormal basis P, Q, R and S of the vector space of complex 2 times 2
matrices. Our method studied here is a natural extension of the approach in the
classical random walk.Comment: 15 pages, small corrections, journal reference adde
Reentrant phase diagram of branching annihilating random walks with one and two offsprings
We investigate the phase diagram of branching annihilating random walks with
one and two offsprings in one dimension. A walker can hop to a nearest neighbor
site or branch with one or two offsprings with relative ratio. Two walkers
annihilate immediately when they meet. In general, this model exhibits a
continuous phase transition from an active state into the absorbing state
(vacuum) at a finite hopping probability. We map out the phase diagram by Monte
Carlo simulations which shows a reentrant phase transition from vacuum to an
active state and finally into vacuum again as the relative rate of the
two-offspring branching process increases. This reentrant property apparently
contradicts the conventional wisdom that increasing the number of offsprings
will tend to make the system more active. We show that the reentrant property
is due to the static reflection symmetry of two-offspring branching processes
and the conventional wisdom is recovered when the dynamic reflection symmetry
is introduced instead of the static one.Comment: 14 pages, Revtex, 4 figures (one PS figure file upon request)
(submitted to Phy. Rev. E
Precise Critical Exponents for the Basic Contact Process
We calculated some of the critical exponents of the directed percolation
universality class through exact numerical diagonalisations of the master
operator of the one-dimensional basic contact process. Perusal of the power
method together with finite-size scaling allowed us to achieve a high degree of
accuracy in our estimates with relatively little computational effort. A simple
reasoning leading to the appropriate choice of the microscopic time scale for
time-dependent simulations of Markov chains within the so called quantum chain
formulation is discussed. Our approach is applicable to any stochastic process
with a finite number of absorbing states.Comment: LaTeX 2.09, 9 pages, 1 figur
Duality relations for the ASEP conditioned on a low current
We consider the asymmetric simple exclusion process (ASEP) on a finite
lattice with periodic boundary conditions, conditioned to carry an atypically
low current. For an infinite discrete set of currents, parametrized by the
driving strength , , we prove duality relations which arise from
the quantum algebra symmetry of the generator of the
process with reflecting boundary conditions. Using these duality relations we
prove on microscopic level a travelling-wave property of the conditioned
process for a family of shock-antishock measures for particles: If the
initial measure is a member of this family with microscopic shocks at
positions , then the measure at any time of the process
with driving strength is a convex combination of such measures with
shocks at positions . which can be expressed in terms of
-particle transition probabilities of the conditioned ASEP with driving
strength .Comment: 26 page
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