3,288 research outputs found
Extensional Collapse Situations I: non-termination and unrecoverable errors
We consider a simple model of higher order, functional computation over the
booleans. Then, we enrich the model in order to encompass non-termination and
unrecoverable errors, taken separately or jointly. We show that the models so
defined form a lattice when ordered by the extensional collapse situation
relation, introduced in order to compare models with respect to the amount of
"intensional information" that they provide on computation. The proofs are
carried out by exhibiting suitable applied {\lambda}-calculi, and by exploiting
the fundamental lemma of logical relations
The Impact of the “Dukes” Case on Retail Employers
[Excerpt] In the past, the notion of a large class action discrimination suit against a national retailer has been a true threat- a tool in the arsenal of the employees- to be feared by the employer. With the Supreme Court decision in Wal-Mart Stores, Inc. v. Dukes, that arsenal has been significantly depleted and the large retailer now treads on somewhat new ground when thinking about discrimination lawsuits.
This paper will discuss some of the more recent class action discrimination suits against large U.S. retailers. It will then discuss the narrative behind the Dukes case, the way in which the opinion could potentially affect the substance of Title VII, and the consequences the Dukes decision holds for human resource departments at large retailers throughout the country
Qualitative and analytical results of the bifurcation thresholds to halo orbits
We study the dynamics in the neighborhood of the collinear Lagrangian points
in the spatial, circular, restricted three--body problem. We consider the case
in which one of the primaries is a radiating body and the other is oblate
(although the latter is a minor effect). Beside having an intrinsic
mathematical interest, this model is particularly suited for the description of
a mission of a spacecraft (e.g., a solar sail) to an asteroid.
The aim of our study is to investigate the occurrence of bifurcations to halo
orbits, which take place as the energy level is varied. The estimate of the
bifurcation thresholds is performed by analytical and numerical methods: we
find a remarkable agreement between the two approaches. As a side result, we
also evaluate the influence of the different parameters, most notably the solar
radiation pressure coefficient, on the dynamical behavior of the model.
To perform the analytical and numerical computations, we start by
implementing a center manifold reduction. Next, we estimate the bifurcation
values using qualitative techniques (e.g. Poincar\'e surfaces, frequency
analysis, FLIs). Concerning the analytical approach, following \cite{CPS} we
implement a resonant normal form, we transform to suitable action-angle
variables and we introduce a detuning parameter measuring the displacement from
the synchronous resonance. The bifurcation thresholds are then determined as
series expansions in the detuning. Three concrete examples are considered and
we find in all cases a very good agreement between the analytical and numerical
results
Inhabitation for Non-idempotent Intersection Types
The inhabitation problem for intersection types in the lambda-calculus is
known to be undecidable. We study the problem in the case of non-idempotent
intersection, considering several type assignment systems, which characterize
the solvable or the strongly normalizing lambda-terms. We prove the
decidability of the inhabitation problem for all the systems considered, by
providing sound and complete inhabitation algorithms for them
Full Abstraction for the Resource Lambda Calculus with Tests, through Taylor Expansion
We study the semantics of a resource-sensitive extension of the lambda
calculus in a canonical reflexive object of a category of sets and relations, a
relational version of Scott's original model of the pure lambda calculus. This
calculus is related to Boudol's resource calculus and is derived from Ehrhard
and Regnier's differential extension of Linear Logic and of the lambda
calculus. We extend it with new constructions, to be understood as implementing
a very simple exception mechanism, and with a "must" parallel composition.
These new operations allow to associate a context of this calculus with any
point of the model and to prove full abstraction for the finite sub-calculus
where ordinary lambda calculus application is not allowed. The result is then
extended to the full calculus by means of a Taylor Expansion formula. As an
intermediate result we prove that the exception mechanism is not essential in
the finite sub-calculus
EUROPEAN LABOUR PRODUCTIVITY AND CORPORATE E-LEARNING ACTIVITIES: AN EMPIRICAL ANALYSIS
The purpose of this analysis is to test the hypothesis which growth in workers’ competency level is affected by educational, training and workplace features. We focused above all on the corporate e-learning activities and labour productivity, in order to identify differences between European countries. Our findings showed some statistical significances related to six variables concerning a macro view of knowledge and innovation in the workplace, whereby we highlighted the comparison of mutual positions of European countries on the basis of a potential component of investments in human capital which is e-learning. According to statistical significativity we specifically noted that most Northern European countries have a comparative advantage in terms of labour productivity and direct investments than those in the south.corporate e-learning, European labour productivity, principal component analysis
The Gaia Data Release 1 parallaxes and the distance scale of Galactic planetary nebulae
In this paper we gauge the potentiality of Gaia in the distance scale
calibration of planetary nebulae (PNe) by assessing the impact of DR1
parallaxes of central stars of Galactic PNe (CSPNe) against known physical
relations. For selected PNe targets with state-of-the-art data on angular sizes
and fluxes, we derive the distance-dependent parameters of the classical
distance scales, i.e., physical radii and ionized masses, from DR1 parallaxes;
we propagate the uncertainties in the estimated quantities and evaluate their
statistical properties in the presence of large relative parallax errors; we
populate the statistical distance scale diagrams with this sample and discuss
its significance in light of existing data and current calibrations.
We glean from DR1 parallaxes 8 CSPNe with S/N1. We show that this set of
potential calibrators doubles the number of extant trigonometric parallaxes
(from HST and ground-based), and increases by two orders of magnitude the
domain of physical parameters probed previously. We then use the combined
sample of suitable trigonometric parallaxes to fit the
physical-radius-to-surface-brightness relation. This distance scale
calibration, although preliminary, appears solid on statistical grounds, and
suggestive of new PNe physics.
With the tenfold improvement in PNe number statistics and astrometric
accuracy expected from future Gaia releases the new distance scale, already
very intriguing, will be definitively constrained.Comment: New Astronomy, in pres
Science and the Courts
"Science and the Courts" is a module meant to illustrate how one might teach exemplary engineering content from the perspective of the humanities and social sciences - the aim of the proposed Bachelor of Arts in "Liberal Studies in Engineering
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