835 research outputs found
Alien Registration- Mckay, Frank H. (Topsham, Sagadahoc County)
https://digitalmaine.com/alien_docs/9368/thumbnail.jp
UK Letter Mail Demand: A Content Based Time Series Analysis Using Overlapping Market Survey Statistical Techniques
Measuring time perspective in adolescents : can you get the right answer by asking the wrong questions?
Time perspective continues to evolve as a psychological construct. The extant literature suggests that higher future orientation and lower present orientation are associated with better developmental outcomes. However, the extant literature also suggests that issues remain with the measurement of the construct. Recently, a 25-item version of the Zimbardo Time Perspective Inventory (ZTPI-25) was suggested for use based on high internal consistency estimates and good discriminant validity of scores in a sample of Italian adolescents. However, the genesis of this scale is uncertain. The present study examined the factorial validity, reliability, and concurrent validity of ZTPI-25 scores in Slovenian, American, and British adolescents. Results revealed satisfactory concurrent validity based on correlations with measures used in the development of the full ZTPI. However, internal consistency and factorial validity of scores were unsatisfactory. The present study questions the use of the ZTPI-25 with adolescents in the context of conceptual and measurement issues more broadly
A call for cautious interpretation of meta-analytic reviews
Meta-analytic reviews collect available empirical studies on a specified domain and calculate the average effect of a factor. Educators as well as researchers exploring a new domain of inquiry may rely on the conclusions from meta-analytic reviews rather than reading multiple primary studies. This article calls for caution in this regard, because the outcome of a meta-analysis is determined by how effect sizes are calculated, how factors are defined, and how studies are selected for inclusion. Three recently published meta-analyses are re-examined to illustrate these issues. One illustrates the risk of conflating effect sizes from studies with different design features, another illustrates problems with delineating the variable of interest, with implications for cause-effect relations, and the third illustrates the challenge of determining the eligibility of candidate studies. Replication attempts yield outcomes that differ from the three original meta-analyses, suggesting that also conclusions drawn from meta-analyses need to be interpreted cautiously
UK Letter Mail Demand: A Content Based Time Series Analysis Using Overlapping Market Survey Statistical Techniques
Competition has become increasingly important in the postal sector for some time in the form of alternative entrants providing mail delivery. However, the competition from ICT in the form of email and instant messaging, the Internet, Facebook and other forms of social networking and portable wireless devices such as the iPad and Kindle may be even more significant. Mail volumes are falling and the economies of scale that have made possible daily deliveries to every address are being eroded. This book assesses volume these declines resulting from this so-called âeSubstituionâ and looks at the ways the postal sector can adapt to the rapid changes resulting from ICT. The impact of electronic invoicing on transactions mail, and the impact on bulk mail of electronic forms of advertising are examined. Strategies, including pricing and access policies, are discussed in the context of the increasing impact of ICT. A rethinking of the role of mail in an electronic age is taking place and this book provides the cutting-edge of this rethinking and the attempts of POs to reinvent themselves while continuing to meet the publicâs expectation of continuing ubiquitous daily deliveries of traditional mail products
Satellite Kinematics I: A New Method to Constrain the Halo Mass-Luminosity Relation of Central Galaxies
Satellite kinematics can be used to probe the masses of dark matter haloes of
central galaxies. In order to measure the kinematics with sufficient
signal-to-noise, one uses the satellite galaxies of a large number of central
galaxies stacked according to similar properties (e.g., luminosity). However,
in general the relation between the luminosity of a central galaxy and the mass
of its host halo will have non-zero scatter. Consequently, this stacking
results in combining the kinematics of satellite galaxies in haloes of
different masses, which complicates the interpretation of the data. In this
paper we present an analytical framework to model satellite kinematics,
properly accounting for this scatter and for various selection effects. We show
that in the presence of scatter in the halo mass-luminosity relation, the
commonly used velocity dispersion of satellite galaxies can not be used to
infer a unique halo mass-luminosity relation. In particular, we demonstrate
that there is a degeneracy between the mean and the scatter of the halo
mass-luminosity relation. We present a new technique that can break this
degeneracy, and which involves measuring the velocity dispersions using two
different weighting schemes: host-weighting (each central galaxy gets the same
weight) and satellite-weighting (each central galaxy gets a weight proportional
to its number of satellites). The ratio between the velocity dispersions
obtained using these two weighting schemes is a strong function of the scatter
in the halo mass-luminosity relation, and can thus be used to infer a unique
relation between light and mass from the kinematics of satellite galaxies.Comment: 8 pages, 3 figures, MNRAS submitte
Flexible graph matching and graph edit distance using answer set programming
The graph isomorphism, subgraph isomorphism, and graph edit distance problems
are combinatorial problems with many applications. Heuristic exact and
approximate algorithms for each of these problems have been developed for
different kinds of graphs: directed, undirected, labeled, etc. However,
additional work is often needed to adapt such algorithms to different classes
of graphs, for example to accommodate both labels and property annotations on
nodes and edges. In this paper, we propose an approach based on answer set
programming. We show how each of these problems can be defined for a general
class of property graphs with directed edges, and labels and key-value
properties annotating both nodes and edges. We evaluate this approach on a
variety of synthetic and realistic graphs, demonstrating that it is feasible as
a rapid prototyping approach.Comment: To appear, PADL 202
Satellite Kinematics II: The Halo Mass-Luminosity Relation of Central Galaxies in SDSS
The kinematics of satellite galaxies reflect the masses of the extended dark
matter haloes in which they orbit, and thus shed light on the mass-luminosity
relation (MLR) of their corresponding central galaxies. In this paper we select
a large sample of centrals and satellites from the Sloan Digital Sky Survey
(SDSS) and measure the kinematics (velocity dispersions) of the satellite
galaxies as a function of the -band luminosity of the central galaxies.
Using the analytical framework presented in Paper I, we use these data to infer
{\it both} the mean and the scatter of the MLR of central galaxies, carefully
taking account of selection effects and biases introduced by the stacking
procedure. As expected, brighter centrals on average reside in more massive
haloes. In addition, we find that the scatter in halo masses for centrals of a
given luminosity, , also increases with increasing luminosity.
As we demonstrate, this is consistent with , which reflects
the scatter in the conditional probability function , being
independent of halo mass. Our analysis of the satellite kinematics yields
, in excellent agreement with constraints from
clustering and group catalogues, and with predictions from a semi-analytical
model of galaxy formation. We thus conclude that the amount of stochasticity in
galaxy formation, which is characterized by , is well
constrained, is independent of halo mass, and is in good agreement with current
models of galaxy formation.Comment: 17 pages, 12 figures, MNRAS submitte
CoCrFeNi High-Entropy Alloy as an Enhanced Hydrogen Evolution Catalyst in an Acidic Solution
High-entropy alloys (HEAs) have intriguing material properties, but their potential as catalysts has not been widely explored. Based on a concise theoretical model, we predict that the surface of a quaternary HEA of base metals, CoCrFeNi, should go from being nearly fully oxidized except for pure Ni sites when exposed to O2 to being partially oxidized in an acidic solution under cathodic bias, and that such a partially oxidized surface should be more active for the electrochemical hydrogen evolution reaction (HER) in acidic solutions than all the component metals. These predictions are confirmed by electrochemical and surface science experiments: the Ni in the HEA is found to be most resistant to oxidation, and when deployed in 0.5 M H2SO4, the HEA exhibits an overpotential of only 60 mV relative to Pt for the HER at a current density of 1 mA/cm2
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