54,988 research outputs found
Communities' practices of promoting sexual and reproductive health and other knowledge in Mozambique
Analyzing Peer Selection Policies for BitTorrent Multimedia On-Demand Streaming Systems in Internet
The adaptation of the BitTorrent protocol to multimedia on-demand streaming
systems essentially lies on the modification of its two core algorithms, namely
the piece and the peer selection policies, respectively. Much more attention
has though been given to the piece selection policy. Within this context, this
article proposes three novel peer selection policies for the design of
BitTorrent-like protocols targeted at that type of systems: Select Balanced
Neighbour Policy (SBNP), Select Regular Neighbour Policy (SRNP), and Select
Optimistic Neighbour Policy (SONP). These proposals are validated through a
competitive analysis based on simulations which encompass a variety of
multimedia scenarios, defined in function of important characterization
parameters such as content type, content size, and client interactivity
profile. Service time, number of clients served and efficiency retrieving
coefficient are the performance metrics assessed in the analysis. The final
results mainly show that the novel proposals constitute scalable solutions that
may be considered for real project designs. Lastly, future work is included in
the conclusion of this paper.Comment: 19 PAGE
PRHOLO: 360Âș Interactive Public Relations
In the globalized world, possessing good products may not be enough to reach potential clients unless
creative marketing strategies are well delineated. In this context, public relations are also important
when it comes to capture the clientâs attention, making the first contact between the clients and the companyâs products, while being persuasive enough to make them confident that the company has the right
products to fit their needs. Three virtual public relations installations were purposed in this chapter,
combining technology with a human like public relations ability, capable of interacting with potential
clients located in front of the installation, at angles of up to 57Âș (degrees), 180Âș and 360Âș, respectively.
From one to several Microsoft Kinects were used to develop the three interaction models, which allows
tracking and recognition of usersâ gestures and positions (heat map), sound sources, voice commands
and face and body extraction of the user interacting with the installation.info:eu-repo/semantics/publishedVersio
A model for the Yield curve
The starting point is an interrogation about the non-broken character of the term structure of interest rates. Some arguments for that smooth character are presented here, all of which are based upon the assumption that market participants - arbitrageurs and speculators - always try to explore any misalignments discovered in the interest market. This led to the basic concept behind the model that the current short-term rate determines most of the value of the rate level for the subsequent period. A linear model describing that simple relationship is assumed and that constitutes the building block from where one can develop the mathematical equations necessary to work with different sets of market data. A number of different yield curves were modelled by adjustment to real market data using this basic model, all of them showing a very high quality of the fits when measured by the non-linear ratio R2. Nevertheless this fact still needs to be confirmed as the examples were drawn from non-independent markets and from a very short time window. The model can be improved by simple addition of a liquidity premium depend only upon the maturity of the rates. However, that improvement sophisticates tremendously the mathematical tractability of any real situation without any assurance that this added cost compensates for the increased quality of the fit. The model is designed around only 3 parameters that can all be interpreted in economic terms. Two of them, in particular, bring a significant improvement over the traditional views frequently extracted from the shape of the yield curve. Provided future tests confirm the high quality of the basic and the improved (with a liquidity premium) models, both are supportive of the expectation hypothesis (EH) and the liquidity premium hypothesis (LPH).
Gauge Fixing in the Maxwell Like Gravitational Theory in Minkowski Spacetime and in the Equivalent Lorentzian Spacetime
In a previous paper we investigate a Lagrangian field theory for the
gravitational field (which is there represented by a section g^a of the
orthonormal coframe bundle over Minkowski spacetime. Such theory, under
appropriate conditions, has been proved to be equivalent to a Lorentzian
spacetime structure, where the metric tensor satisfies Einstein field
equations. Here, we first recall that according to quantum field theory ideas
gravitation is described by a Lagrangian theory of a possible massive graviton
field (generated by matter fields and coupling also to itself) living in
Minkowski spacetime. The graviton field is moreover supposed to be represented
by a symmetric tensor field h carrying the representations of spin two and zero
of the Lorentz group. Such a field, then (as it is well known), must
necessarily satisfy the gauge condition given by Eq.(3) below. Next, we
introduce an ansatz relating h to the 1-form fields g^a. Then, using the
Clifford bundle formalism we derive, from our Lagrangian theory, the exact wave
equation for the graviton and investigate the role of the gauge condition given
by Eq.(3) in obtaining a reliable conservation law for the energy-momentum
tensor of the gravitational plus the matter fields in Minkowski spacetime.
Finally we ask the question: does Eq.(3) fix any gauge condition for the field
g of the effective Lorentzian spacetime structure that represents the field h
in our theory? We show that no gauge condition is fixed a priory, as is the
case in General Relativity. Moreover we investigate under which conditions we
may fix Logunov gauge condition.Comment: 15 pages. This version corrects some misprints of the published
versio
Diffeomorphism Invariance and Local Lorentz Invariance
We show that diffeomorphism invariance of the Maxwell and the Dirac-Hestenes
equations implies the equivalence among different universe models such that if
one has a linear connection with non-null torsion and/or curvature the others
have also. On the other hand local Lorentz invariance implies the surprising
equivalence among different universe models that have in general different
G-connections with different curvature and torsion tensors.Comment: 19 pages, Revtex, Plenary Talk presented at VII International
Conference on Clifford Algebras and their Applications, Universite Paul
Sabatier UFR MIG, Toulouse (FRANCE), to appear in "Clifford Algebras,
Applications to Mathematics, Physics and Engineering", Progress in Math.
Phys., Birkhauser, Berlin 200
Realizing the supersymmetric inverse seesaw model in the framework of R-parity violation
If, on one hand, the inverse seesaw is the paradigm of TeV scale seesaw
mechanism, on the other it is a challenge to find scenarios capable of
realizing it. In this work we propose a scenario, based on the framework of
R-parity violation, that realizes minimally the supersymmetric inverse seesaw
mechanism. In it the energy scale parameters involved in the mechanism are
recognized as the vacuum expectation values of the scalars that compose the
singlet superfields and . We develop also the scalar sector
of the model and show that the Higgs mass receives a new tree-level
contribution that, when combined with the standard contribution plus loop
correction, is capable of attaining GeV without resort to heavy stops.Comment: Minor modification of the text. Final version to be published in PL
Overconfidence and excess entry: a comparison between students and managers
Overconfidence can lead to excessive business entry. Here we replicate the pioneer experiment finding this nexus (Camerer and Lovallo 1999) and extend it in two major directions: (1) to consider managers as well as student subjects and (2) to explicitly take into account selected characteristics of the manager subjects. We find that managers are more prone to the nexus overconfidence-excess entry than students are. In particular, we find that left-handed, married, and emotionally aroused managers are more prone to excess entry.excess business entry, overconfidence, unrealistic optimism
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