396 research outputs found
Leading advertisers efficiency evaluated by data envelopment analysis
In this paper we analyze the problem of measuring the advertising efficiency of the Leading US Advertisers during the period 2001-2006. We use the DEA (Data Envelopment Analysis) approach that enables to evaluate the relative efficiency in case of multiple inputs and outputs. In particular, the classical CCR-DEA model is first implemented in each year considered; a windows analysis approach is then used in order to better capture the dynamics of efficiency. Finally, the effect on efficiency of advertising spending over time, is captured by Adstock as an additional variable of the DEA model. The dynamics of Adstock is described by a finite difference equation.
A fractional optimal control problem for maximizing advertising efficiency
We propose an optimal control problem to model the dynamics of the communication activity of a firm with the aim of maximizing its efficiency. We assume that the advertising effort undertaken by the firm contributes to increase the firm's goodwill and that the goodwill affects the firm's sales. The aim is to find the advertising policies in order to maximize the firm's efficiency index which is computed as the ratio between "outputs" and "inputs" properly weighted; the outputs are represented by the final level of goodwill and by the sales achieved by the firm during the period considered, whereas the inputs are represented by the costs undertaken by the firm, fixed costs and advertising costs. The problem considered is formulated as a fractional optimal control problem. In order to find the optimal advertising policies we use the Dinkelbach's algorithm for fractional programming.
A Concrete Composite 2-Higgs Doublet Model
We consider a Composite Higgs Model (CHM) with two isospin doublet Higgs
fields arising as pseudo Nambu-Goldstone bosons from a breaking. The main focus of this work is to
explicitly compute the properties of these Higgses in terms of the fundamental
parameters of the composite sector such as masses, Yukawa and gauge couplings
of the new spin-1 and spin-1/2 resonances. Concretely, we calculate the Higgs
potential at one-loop level through the Coleman-Weinberg mechanism from the
explicit breaking of the global symmetry by the partial
compositeness of fermions and gauge bosons. We derive then the phenomenological
properties of the Higgs states and highlight the main signatures of this
Composite 2-Higgs Doublet Model at the Large Hadron Collider, including
modifications to the SM-like Higgs couplings as well as production and decay
channels of heavier Higgs bosons. We also consider flavour bounds that are
typical of CHMs with more than one Higgs doublet.Comment: 45 pages, 16 figures, version accepted for publication in JHE
Subitizing as pattern recognition: evidence for automaticity when non-symbolic number stimuli are canonically arranged
Subitizing allows detecting the quantity of a small set of elements (up to four) with the accuracy of counting and the velocity of estimation. Recent studies have supported a theory which considers subitizing as a visual mechanism of pattern recognition, sensitive to spatial disposition of elements. These studies have found an increase in response rate and accuracy in the assessment of quantity when elements to be enumerated are arranged in an orderly fashion. Whether the numerosity of orderly arranged elements is accessed automatically, without the requirement of attentional resources, is a relevant issue not yet empirically investigated. The current study investigated the relation between subitizing and automaticity in a target detection task where distractors were non-symbolic number stimuli (dot patterns), with two different arrangements, random or canonical (like dice faces), having the same or different numerosity in the number target. We found that with canonical patterns, in the subitizing range, response times were faster in compatible trials, and slower in incompatible trials, compared to random patterns which did not influence response times in any condition. This result revealed that when elements in a visual display form easily recognizable patterns, their numerosity is accessed automatically
Future Electron-Positron Colliders and the 4-Dimensional Composite Higgs Model
In this note we analyse the prospects of a future electron-positron collider
in testing a particular realisation of a composite Higgs model encompassing
partial compositeness, namely, the 4-Dimensional Composite Higgs Model. We
study the main Higgs production channels for three possible energy stages and
different luminosity options of such a machine and confront our results to the
expected experimental accuracies in the various Higgs decay channels accessible
herein and, for comparison, also at the Large Hadron Collider.Comment: 24 pages, 10 figures, minor corrections for publication in JHE
Top pair production at a future machine in a composite Higgs scenario
The top quark plays a central role in many New Physics scenarios and in
understanding the details of Electro-Weak Symmetry Breaking. In the short- and
mid-term future, top-quark studies will mainly be driven by the experiments at
the Large Hadron Collider. Exploration of top quarks will, however, be an
integral part of particle physics studies at any future facility and an collider will have a very comprehensive top-quark physics program. We
discuss the possibilities of testing NP in the top-quark sector within a
composite Higgs scenario through deviations from the Standard Model in top pair
production for different Centre-of-Mass energy options of a future
machine. In particular, we focus on precision studies of the top-quark sector
at a CM energy ranging from 370 GeV up to 3 TeV.Comment: 23 pages, 10 figures; v2: minor corrections, published on JHE
ANNUIRE E SCUOTERE LA TESTA COME AZIONI SIMULATE DI APPROCCIO ED EVITAMENTO Indagine sperimentale sulla relazione tra elaborazione cognitiva e gesti embodied
The study deals with the relationship between language understanding and bodily movements, focusing on the movements involved in the two gestures of nodding and shaking of the head, a body part still not sufficiently investigated within the embodiment perspective. In 4 studies (9 experiments in total) the presence of a motor compatibility effect between the production of vertical and horizontal head movements and a high-level cognitive process such as the evaluation, both semantic and affective, of the truth-value of sentences was investigated. Through an innovative experimental procedure that, thanks to a motion detection software, made it possible to move stimuli on a computer screen directly with the action of the head, it was found that the semantic evaluation activated the simulation of the two head movements as nodding and shaking gestures, only when the evaluation was explicit. On the contrary, the affective evaluation was able to activate the two movements of the head as approach and avoidance responses even when there was no explicit intent to evaluate the stimuli, and generating a broader compatibility effect. Finally, the effect was also tested with a sample of young Bulgarians, for which the same vertical/horizontal movements can elicit the opposite meaning. Overall results show that it is possible, as well as necessary for the enhancement of the embodiment literature, to find reliable, automatic and implicit embodiment effects, and shed light on the possibility to exploit the automatic simulation of approach and avoidance movements with the head, in order to measure implicit attitudes, in social and personality research
Exclusion and discovery via Drell-Yan in the 4DCHM
Searches for Z' bosons are most sensitive in the dilepton channels at hadron
colliders. Whilst finite width and interference effects do affect the
modifications the presence of BSM physics makes to Standard Model (SM)
contributions, generic searches are often designed to minimize these. The
experimental approach adopted works well in the case of popular models that
predict a single and narrow Z' boson allowing these effects to effectively be
neglected. Conversely, finite width and interference effects may have to be
taken into account in experimental analyses when such Z' states are wide or
where several states are predicted. We explore the consequences of these
effects in the 4-Dimensional Composite Higgs Model (4DCHM) which includes
multiple new Z' bosons and where the decays of these resonances to non-SM
fermions can result in large widths
Drell-Yan production of multi Z'-bosons at the LHC within Non-Universal ED and 4D Composite Higgs Models
The Drell-Yan di-lepton production at hadron colliders is by far the
preferred channel to search for new heavy spin-1 particles. Traditionally, such
searches have exploited the Narrow Width Approximation (NWA) for the signal,
thereby neglecting the effect of the interference between the additional
Z'-bosons and the Standard Model Z and {\gamma}. Recently, it has been
established that both finite width and interference effects can be dealt with
in experimental searches while still retaining the model independent approach
ensured by the NWA. This assessment has been made for the case of popular
single Z'-boson models currently probed at the CERN Large Hadron Collider
(LHC). In this paper, we test the scope of the CERN machine in relation to the
above issues for some benchmark multi Z'-boson models. In particular, we
consider Non-Universal Extra Dimensional (NUED) scenarios and the 4-Dimensional
Composite Higgs Model (4DCHM), both predicting a multi-Z' peaking structure. We
conclude that in a variety of cases, specifically those in which the leptonic
decays modes of one or more of the heavy neutral gauge bosons are suppressed
and/or significant interference effects exist between these or with the
background, especially present when their decay widths are significant,
traditional search approaches based on the assumption of rather narrow and
isolated objects might require suitable modifications to extract the underlying
dynamics
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