2,986 research outputs found
Dimensional instability of aluminum alloys for extreme low temperature cycling applications /GGV material instability problem/
Dimensional instability of aluminum alloys during cryogenic thermal cyclin
Exploring relationships between touch perception and surface physical properties
This paper reports a study of materials for confectionery packaging. The aim was to explore the touch perceptions of textures and identify their relationships with the surfaces' physical properties. Thirty-seven tactile textures were tested including 22 cardboards, nine flexible materials and six laminate boards. Semantic differential questionnaires were administered to assess responses to touching the textures against six word pairs: warm-cold, slippery-sticky, smooth,-rough, hard-soft, bumpy-flat, and wet-dry. Four physical measurements were conducted to characterize the surfaces' roughness, compliance, friction, and the rate of cooling of an artificial finger when touching the surface. Correlation and regression analyses were carried out to identify the relationships between the people's responses and the physical measurements. Results show that touch perception is often associated with more than one physical property, and the strength and form of the combined contribution can be represented by a regression model. © 2009 Chen, Shao, Barnes, Childs, & Henson
Gravity and Matter in Causal Set Theory
The goal of this paper is to propose an approach to the formulation of
dynamics for causal sets and coupled matter fields. We start from the continuum
version of the action for a Klein-Gordon field coupled to gravity, and rewrite
it first using quantities that have a direct correspondent in the case of a
causal set, namely volumes, causal relations, and timelike lengths, as
variables to describe the geometry. In this step, the local Lagrangian density
for a set of fields is recast into a quasilocal expression
that depends on pairs of causally related points and
is a function of the values of in the Alexandrov set defined by those
points, and whose limit as and approach a common point is .
We then describe how to discretize , and use it to define a
discrete action.Comment: 13 pages, no figures; In version 2, friendlier results than in
version 1 are obtained following much shorter derivation
Quantum Gravity Phenomenology, Lorentz Invariance and Discreteness
Contrary to what is often stated, a fundamental spacetime discreteness need
not contradict Lorentz invariance. A causal set's discreteness is in fact
locally Lorentz invariant, and we recall the reasons why. For illustration, we
introduce a phenomenological model of massive particles propagating in a
Minkowski spacetime which arises from an underlying causal set. The particles
undergo a Lorentz invariant diffusion in phase space, and we speculate on
whether this could have any bearing on the origin of high energy cosmic rays.Comment: 13 pages. Replaced version with corrected fundamental solution,
missing m's (mass) and c's (speed of light) added and reference on diffusion
on the three sphere changed. Note with additional references added and
addresses updated, as in published versio
Bias and Precision of the Squared Canonical Correlation Coefficient Under Nonnormal Data Condition
Monte Carlo methods were employed to investigate the effect of nonnormality on the bias associated with the squared canonical correlation coefficient (Rc2). The majority of Rc2 estimates were found to be extremely biased, but the magnitude of bias was impacted little by the degree of nonnormality
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