15,107 research outputs found
The 1985 Chile earthquake: Structural characteristics and damage statistics for the building inventory in Vina del Mar
The Chile earthquake of 3 March 1985 resulted in an effective peak
acceleration of 0.36g in the coastal city of Vina del Mar. The city
had an inventory of over 400 reinforced concrete buildings ranging in
height from 5 to 23 stories. The observed behavior of the buildings is
interpreted in relation to the physical characteristics of the
structural systems.National Science Foundation Grant ECE 86-0378
Functional contributions of bootlegging and entrepreneurship in research organizations
Bootlegging and entrepreneurship by scientists in research organization
Solomonoff Induction Violates Nicod's Criterion
Nicod's criterion states that observing a black raven is evidence for the
hypothesis H that all ravens are black. We show that Solomonoff induction does
not satisfy Nicod's criterion: there are time steps in which observing black
ravens decreases the belief in H. Moreover, while observing any computable
infinite string compatible with H, the belief in H decreases infinitely often
when using the unnormalized Solomonoff prior, but only finitely often when
using the normalized Solomonoff prior. We argue that the fault is not with
Solomonoff induction; instead we should reject Nicod's criterion.Comment: ALT 201
The ``Outside-In'' Outburst of HT Cassiopeiae
We present results from photometric observations of the dwarf nova system HT
Cas during the eruption of November 1995. The data include the first
two--colour observations of an eclipse on the rise to outburst. They show that
during the rise to outburst the disc deviates significantly from steady state
models, but the inclusion of an inner-disc truncation radius of about 4
and a ``flared'' disc of semi-opening angle of produces
acceptable fits. The disc is found to have expanded at the start of the
outburst to about , as compared to quiescent measurements. The
accretion disc then gradually decreases in radius reaching during
the last stages of the eruption. Quiescent eclipses were also observed prior to
and after the eruption and a revised ephemeris is calculated.Comment: 9 pages, 11 figures, to appear in MNRA
Dark Matter from the Inflaton Field
We present a model where inflation and Dark Matter takes place via a single
scalar field phi. Without introducing any new parameters we are able unify
inflation and Dark Matter using a scalar field phi that accounts for inflation
at an early epoch while it gives a Dark Matter WIMP particle at low energies.
After inflation our universe must be reheated and we must have a long period of
radiation dominated before the epoch of Dark Matter. Typically the inflaton
decays while it oscillates around the minimum of its potential. If the inflaton
decay is not complete or sufficient then the remaining energy density of the
inflaton after reheating must be fine tuned to give the correct amount of Dark
Matter. An essential feature here, is that Dark Matter-Inflaton particle is
produced at low energies without fine tuning or new parameters. This process
uses the same coupling g as for the inflaton decay. Once the field phi becomes
non-relativistic it will decouple as any WIMP particle, since n_phi is
exponentially suppressed. The correct amount of Dark Matter determines the
cross section and we have a constraint between the coupling and the mass
of phi. The unification scheme we present here has four free parameters,
two for the scalar potential V(phi) given by the inflation parameter lambda of
the quartic term and the mass m_o. The other two parameters are the coupling
between the inflaton phi and a scalar filed varphi and the coupling h
between varphi with standard model particles psi or chi. These four parameters
are already present in models of inflation and reheating process, without
considering Dark Matter. Therefore, our unification scheme does not increase
the number of parameters and it accomplishes the desired unification between
the inflaton and Dark Matter for free.Comment: 9 pages, 3 figures. arXiv admin note: substantial text overlap with
arXiv:0911.517
Inter-rater reliability of the Dysexecutive Questionnaire (DEX): comparative data from non-clinician respondents – all raters are not equal
Primary objective: The Dysexecutive Questionnaire (DEX) is used to obtain information about executive and emotional problems after neuropathology. The DEX is self-completed by the patient (DEX-S) and an independent rater such as a family member (DEX-I). This study examined the level of inter-rater agreement between either two or three non-clinician raters on the DEX-I in order to establish the reliability of DEX-I ratings.
Methods and procedures: Family members and/or carers of 60 people with mixed neuropathology completed the DEX-I. For each patient, DEX-I ratings were obtained from either two or three raters who knew the person well prior to brain injury.
Main outcomes and results: We obtained two independent-ratings for 60 patients and three independent-ratings for 36 patients. Intra-class correlations revealed that there was only a modest level of agreement for items, subscale and total DEX scores between raters for their particular family member. Several individual DEX items had low reliability and ratings for the emotion sub-scale had the lowest level of agreement.
Conclusions: Independent DEX ratings completed by two or more non-clinician raters show only moderate correlation. Suggestions are made for improving the reliability of DEX-I ratings.</p
Interacting dark energy: generic cosmological evolution for two scalar fields
We study the cosmological evolution of two coupled scalar fields with an
arbitrary interaction term V_T(\phi,\vp) in the presence of a barotropic fluid,
which can be matter or radiation. The force between the barotropic fluid and
the scalar fields is only gravitational. We show that the dynamics is
completely determine by only three parameters L_i i=1,2,3. We determine all
critical points and study their stability. We find six different attractor
solutions depending on the values of L_i and we calculate the relevant
cosmological parameters. We discuss the possibility of having one of the scalar
fields as of dark energy while the other could be a scalar field redshifting as
matter.Comment: 13 pages, 16 figure
Business and society on the transitional periphery: Comparative perspectives
This article looks at business and society on the transitional periphery from a starting point rooted in the international business literature. Many transitional periphery countries have rich natural resource endowments or prosperous diasporas, making it relatively easy to attract inward FDI, chronic institutional weaknesses and policy failures notwithstanding. At the same time, such windfalls may dilute incentives for institution building or reform. We review trends emerging from the most recent scholarly work in the area, and highlight potential research agendas for the future
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