1,330 research outputs found
Estimating Attendance From Cellular Network Data
We present a methodology to estimate the number of attendees to events
happening in the city from cellular network data. In this work we used
anonymized Call Detail Records (CDRs) comprising data on where and when users
access the cellular network. Our approach is based on two key ideas: (1) we
identify the network cells associated to the event location. (2) We verify the
attendance of each user, as a measure of whether (s)he generates CDRs during
the event, but not during other times. We evaluate our approach to estimate the
number of attendees to a number of events ranging from football matches in
stadiums to concerts and festivals in open squares. Comparing our results with
the best groundtruth data available, our estimates provide a median error of
less than 15% of the actual number of attendees
Market-Driven Management, Competitive Customer Value and Global Network
Market-Driven Management is a corporate strategy that presupposes direct,
continuous benchmarking with competitors, in a context of customer value management. Market-driven management therefore favours an 'outside-in' vision, based on: the identification of products with a higher value than that of the competition to provoke the intersection with demand ('Before and Better than Competitors'). In global over-supplied markets, a firm's success is conditioned rather by the intensity of the presence and by the level of sophistication of intangible corporate asset; in other words, the peculiar managerial capabilities that regard brand equity, information system and corporate culture.Market-Driven Management; Global Competition; Global Managerial Economics; Brand Equity; Information System; Corporate Culture
Undersaturation of quarks at early stages of relativistic nuclear collisions: the hot glue initial scenario and its observable signatures
The early stage of high multiplicity nuclear collisions is represented by a
nearly quarkless, hot, deconfined pure gluon plasma. This new scenario should
be characterized by a suppression of high photons and dileptons as well
as by reduced baryon to meson ratios. We present the numerical results for
central Pb+Pb collisions at the LHC energies by using the ideal Bjorken
hydrodynamics with time-dependent quark fugacity. It is shown that about 25\%
of final total entropy is generated during the hydrodynamic evolution of
chemically undersaturated quark-gluon plasma.Comment: 5 pages, 7 figures, proceeding for STARS2015 symposiu
Transverse expansion of hot magnetized Bjorken flow in heavy ion collisions
We argue that the existence of an inhomogeneous external magnetic field can
lead to radial flow in transverse plane. Our aim is to show how the
introduction of a magnetic field generalizes the Bjorken flow. We investigate
the effect of an inhomogeneous weak external magnetic field on the transverse
expansion of in-viscid fluid created in high energy nuclear collisions. In
order to simplify our calculation and compare with Gubser model, we consider
the fluid under investigation to be produced in central collisions, at small
impact parameter; azimuthal symmetry has been considered. In our model, we
assume an inhomogeneous external magnetic field following the power-law decay
in proper time and having radial inhomogeneity perpendicular to the radial
velocity of the in-viscid fluid in the transverse plane; then the space time
evolution of the transverse expansion of the fluid is obtained. We also show
how the existence of an inhomogeneous external magnetic field modifies the
energy density. Finally we use the solutions for the transverse velocity and
energy density in the presence of a weak magnetic field, to estimate the
transverse momentum spectrum of protons and pions emerging from the
Magneto-hydrodynamic solutions
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