10,004 research outputs found

    The MSSM from Scherk-Schwarz Supersymmetry Breaking

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    We present a five-dimensional model compactified on an interval where supersymmetry is broken by the Scherk-Schwarz mechanism. The gauge sector propagates in the bulk, two Higgs hypermultiplets are quasilocalized, and quark and lepton multiplets localized, in one of the boundaries. The effective four-dimensional theory is the MSSM with very heavy gauginos, heavy squarks and light sleptons and Higgsinos. The soft tree-level squared masses of the Higgs sector can be negative and they can (partially) cancel the positive one-loop contributions from the gauge sector. Electroweak symmetry breaking can then comfortably be triggered by two-loop radiative corrections from the top-stop sector. The fine tuning required to obtain the electroweak scale is found to be much smaller than in the MSSM, with essentially no fine-tuning for few TeV gaugino masses. All bounds from direct Higgs searches at LEP and from electroweak precision observables can be satisfied. The lightest supersymmetric particle is a (Higgsino-like) neutralino that can accomodate the abundance of Dark Matter consistently with recent WMAP observations.Comment: 23 pages, 3 figure

    The role and potential of tripartite partnerships to promote strong sustainable consumption in the context of Brazil: an evaluation of possibilities and risks

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    The growing concern about persisting environmental problems caused by overconsumption in the context of Brazil must be understood as an issue of democratic character. However, there is a gap in research examining models that can drive change of sustainable-related issues such as sustainable consumption. Critically evaluating existing literature, we discuss the potential of tripartite partnerships (TPPs) to advance sustainable consumption practices. We argue that multi-sector partnership approaches such as TPPs involving multiple actors can strengthen a socio-political basis for the advancement of public policies and inter-sectorial dynamics offering mechanisms that can foster sustainable consumption. By applying a TPP model as analytical lens, we explore prevalent possibilities and risks of promoting sustainable consumption in the context of Brazil

    Models for pheromone evaluation in Ant Systems for Mobile Ad-hoc networks

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    On a mobile ad-hoc network environment, where the resources are scarce, the knowledge about the network's link state is essential to optimize the routing procedures. This paper presents a study about different pheromone evaluation models and how they react to possible changes in traffic rate. Observing how the pheromone value on a link changes, it could be possible to identify certain patterns which can indicate the path status. For this study, the behavior of the Ant System evaluation model was compared with a Temporal Active Pheromone model (a biological approach) and a Progressive Pheromone Reduction model with and without a maximum pheromone limit

    Models for pheromone evaluation in Ant Systems for Mobile Ad-hoc networks

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    On a mobile ad-hoc network environment, where the resources are scarce, the knowledge about the network's link state is essential to optimize the routing procedures. This paper presents a study about different pheromone evaluation models and how they react to possible changes in traffic rate. Observing how the pheromone value on a link changes, it could be possible to identify certain patterns which can indicate the path status. For this study, the behavior of the Ant System evaluation model was compared with a Temporal Active Pheromone model (a biological approach) and a Progressive Pheromone Reduction model with and without a maximum pheromone limit

    Digital learning object for audiovisual production

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    Funding Information: ACKNOWLEDGMENT A.V. M. Author thanks to the professors and technicians of Federal University of Paraíba (UFPB) who assisted with permissions, classrooms, studios, laboratories, and equipment for the research. Thanks also for the support of the Faculty of Science and Technology (FCT) of the New University of Lisbon (NOVA).This article deals with a case study in which a digital learning object (DLO) was developed to assist in the pedagogical practice in higher education (audiovisual area). The main results obtained were the excellent conceptual evaluation received by the DLO tool; as well as great concepts received in evaluations that refer to relevance, differentiation, credibility, and intention to use (among other metrics). In addition, a blind analysis also showed that there was no qualitative difference between the practical work developed with or without the aid of the tool (due to a potential gain of time that could be perceived and enjoyed for the execution of the activities performed, due to an automation process offered by the tool). The final conclusions pointed to a positive indication of the use of DLOs in teaching practice in higher education, as the digital tool was very well received by students during classes and helped to review and reinforce the learning content taught. Thus, the study reinforces the research developed in the area of education on the effectiveness of the use of technologies in supporting pedagogical activities, besides adding another experiment related to mixed digital learning. However, it stresses that collaborative research can lead to a further analysis of the pedagogical contributions of DLOs.publishersversionpublishe
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