10,052 research outputs found
Effective Actions for Heterotic M-Theory
We discuss the moduli space approximation for heterotic M-theory, both for
the minimal case of two boundary branes only, and when a bulk brane is
included. The resulting effective actions may be used to describe the
cosmological dynamics in the regime where the branes are moving slowly, away
from singularities. We make use of the recently derived colliding branes
solution to determine the global structure of moduli space, finding a boundary
at which the trajectories undergo a hard wall reflection. This has important
consequences for the allowed moduli space trajectories, and for the behaviour
of cosmological perturbations in the model.Comment: 21 pages, 4 figures. References added and some discussions clarifie
Flavor structure with multi moduli in 5D supergravity
We study 5-dimensional supergravity on S^1/Z_2 with a physical Z_2-odd vector
multiplet, which yields an additional modulus other than the radion. We derive
4-dimensional effective theory and find additional terms in the Kahler
potential that are peculiar to the multi moduli case. Such terms can avoid
tachyonic soft scalar masses at tree-level, which are problematic in the single
modulus case. We also show that the flavor structure of the soft terms are
different from that in the single modulus case when hierarchical Yukawa
couplings are generated by wavefunction localization in the fifth dimension. We
present a concrete model that stabilizes the moduli at a supersymmetry breaking
Minkowski minimum, and show the low energy sparticle spectrum.Comment: 30 pages, 2 figures; version to be published in PR
Corrections to the Boltzmann mean free path in disordered systems with finite size scatterers
The mean free path is an essential characteristic length in disordered
systems. In microscopic calculations, it is usually approximated by the
classical value of the elastic mean free path. It corresponds to the Boltzmann
mean free path when only isotropic scattering is considered, but it is
different for anisotropic scattering. In this paper, we work out the
corrections to the so called Boltzmann mean free path due to multiple
scattering effects on finite size scatterers, in the s-wave approximation, ie.
when the elastic mean free path is equivalent to the Boltzmann mean free path.
The main result is the expression for the mean free path expanded in powers of
the perturbative parameter given by the scatterer density.Comment: 12 page
New sufficient conditions to ulam stabilities for a class of higher order integro-differential equations
In this work, we present sufficient conditions in order to establish different types of Ulam stabilities for a class of higher order integro-differential equations. In particular, we consider a new kind of stability, the sigma-semi-Hyers-Ulam stability, which is in some sense between the Hyers-Ulam and the Hyers-Ulam-Rassias stabilities. These new sufficient conditions result from the application of the Banach Fixed Point Theorem, and by applying a specific generalization of the Bielecki metric.publishe
Stochastic Optimization for Network-Constrained Power System Scheduling Problem
The stochastic nature of demand and wind generation has a considerable effect on solving the scheduling problem of a modern power system. Network constraints such as power flow equations and transmission capacities also need to be considered for a comprehensive approach to model renewable energy integration and analyze generation system flexibility. Firstly, this paper accounts for the stochastic inputs in such a way that the uncertainties are modeled as normally distributed forecast errors. The forecast errors are then superimposed on the outputs of load and wind forecasting tools. Secondly, it efficiently models the network constraints and tests an iterative algorithm and a piecewise linear approximation for representing transmission losses in mixed integer linear programming (MILP). It also integrates load shedding according to priority factors set by the system operator. Moreover, the different interactions among stochastic programming, network constraints, and prioritized load shedding are thoroughly investigated in the paper. The stochastic model is tested on a power system adopted from Jeju Island, South Korea. Results demonstrate the impact of wind speed variability and network constraints on the flexibility of the generation system. Further analysis shows the effect of loss modeling approaches on total cost, accuracy, computational time, and memory requirement
Produção de mudas frutÃferas no Nordeste.
Objetivando conhecer a situacao da producao de mudas no contexto da fruticultura nordestina, a Embrapa Agroindustria Tropical, realizou um levantamento nos estados de Sergipe, Alagoas,Pernambuco, Paraiba, Rio Grande do Norte, Ceara, Piaui e Maranhao.bitstream/CNPAT-2010/5359/1/Ct-027.pd
AI trust: Can explainable AI enhance warranted trust?
Explainable artificial intelligence (XAI), known to produce explanations so that predictions from AI models can be understood, is commonly used to mitigate possible AI mistrust. The underlying premise is that the explanations of the XAI models enhance AI trust. However, such an increase may depend on many factors. This article examined how trust in an AI recommendation system is affected by the presence of explanations, the performance of the system, and the level of risk. Our experimental study, conducted with 215 participants, has shown that the presence of explanations increases AI trust, but only in certain conditions. AI trust was higher when explanations with feature importance were provided than with counterfactual explanations. Moreover, when the system performance is not guaranteed, the use of explanations seems to lead to an overreliance on the system. Lastly, system performance had a stronger impact on trust, compared to the effects of other factors (explanation and risk).info:eu-repo/semantics/publishedVersio
Making robot’s attitudes predictable: a stereotype content model for human-robot interaction in groups
Stereotypes play a key role both in human and in robot perception. As such, these may play an important role in predicting behavior towards the targets of said stereotypes. In this paper, we argue for the usefulness of exploring how stable dimensions of stereotype content, more specific?ally warmth and competence, apply to HRI. We propose to do so by examining the impact of these characteristics, displayed by robots, on the emotions, behaviors and future intention of participants to interact and work with robots. We chose these two stereotypical dimensions given that research has demonstrated their underlying and ubiquitous influence on people perception and responses. Moreover, we decided to explore this issue in the context of small group interactions due to the ever-common nature of this type of social arrangements in people’s everyday life.info:eu-repo/semantics/acceptedVersio
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