Modulation of exploratory behavior for adaptation to the context

For autonomous agents (children, animals or robots), exploratory learning is essential as it allows them to take advantage of their past experiences in order to improve their reactions in any situation similar to a situation already experimented. We have already exposed in Blanchard and Canamero (2005) how a robot can learn which situations it should memorize and try to reach, but we expose here architectures allowing the robot to take initiatives and explore new situations by itself. However, exploring is a risky behavior and we propose to moderate this behavior using novelty and context based on observations of animals behaviors. After having implemented and tested these architectures, we present a very interesting emergent behavior which is low-level imitation modulated by context

Inflation from superstrings

We investigate the possibility of obtaining inflationary solutions of the slow roll type from a low energy Lagrangian coming from superstrings. The advantage of such an approach is that in these theories the scalar potential has only one free parameter (the Planck scale) and therefore no unnatural fine tuning may be accommodated. We find that in any viable scheme the dilaton and the moduli fields have to be stabilized and that before this happens, no other field may be used as the inflaton. Then inflation may occur due to chiral matter fields. Demanding that the potential terms associated with the chiral fields do not spoil the dilaton and moduli minimization leads to severe constraints on the magnitude of the density fluctuations.Comment: 22 pages, no figures, latex file We have corrected the magnitude of the density fluctuations, which become smaller than the COBE ones. Some references have also been added, and a few misprints correcte

Computational simulation of probabilistic lifetime strength for aerospace materials subjected to high temperature, mechanical fatigue, creep and thermal fatigue

This report presents the results of a fourth year effort of a research program, conducted for NASA-LeRC by the University of Texas at San Antonio (UTSA). The research included on-going development of methodology that provides probabilistic lifetime strength of aerospace materials via computational simulation. A probabilistic material strength degradation model, in the form of a randomized multifactor interaction equation, is postulated for strength degradation of structural components of aerospace propulsion systems subject to a number of effects or primitive variables. These primitive variables may include high temperature, fatigue or creep. In most cases, strength is reduced as a result of the action of a variable. This multifactor interaction strength degradation equation has been randomized and is included in the computer program, PROMISS. Also included in the research is the development of methodology to calibrate the above-described constitutive equation using actual experimental materials data together with regression analysis of that data, thereby predicting values for the empirical material constants for each effect or primitive variable. This regression methodology is included in the computer program, PROMISC. Actual experimental materials data were obtained from industry and the open literature for materials typically for applications in aerospace propulsion system components. Material data for Inconel 718 has been analyzed using the developed methodology

Cosmic Ray Signatures from Decaying Gravitino Dark Matter

We study the charged cosmic rays arising from the slow decay of gravitino dark matter within supersymmetric scenarios with trilinear R-parity violation. It is shown that operators of the LLE type can very well account for the recent anomalies in cosmic ray electron and positron data reported by PAMELA, ATIC and Fermi LAT, without violating any other bounds. This scenario will soon be tested by the Fermi LAT data on diffuse gamma ray emission.Comment: To appear in the proceedings of EPS-HEP 2009, Krakow, Polan

Long lived charginos in Natural SUSY?

Supersymmetric models with a small neutralino-chargino mass difference, and as a result metastable charginos, have been a popular topic of investigation in collider phenomenology, e.g. in anomaly-mediated models of supersymmetry breaking. Recently, the absence of any supersymmetric signal at the 8 TeV LHC data has led to significant interest in the so-called Natural SUSY models with light higgsinos. These models also have a naturally small neutralino-chargino mass difference. However, we show here that when relevant indirect constraints from results at the LHC and elsewhere are applied, this possibility is heavily constrained within the Minimal Supersymmetric Standard Model (MSSM): massive metastable higgsinos are not a signature of Natural SUSY.Comment: Extended discussion, updated references, matches version to appear in JHE

Tinkering with Student Speech in the Age of Social Media

This dissertation investigates the issue of public junior high and high school students who are punished at school for their online speech that they created when they were off-campus. Specifically, it examines the issue of when students are punished at school for online speech that criticizes teachers and administrators, rather than the issue of student-on-student cyberbullying. Because the United States Supreme Court has not yet accepted any case that involves off-campus online student speech, this dissertation summarizes and analyzes federal appellate court decisions in such cases. Appellate courts in six federal circuits have heard and ruled in cases involving students’ off-campus online speech. This dissertation examines the precedent those courts have applied to outline the circumstances under which the courts find for the student or school officials. Because court decisions depend on the application of precedential case law, this dissertation includes a thorough examination of those major Supreme Court student speech precedents: West Virginia State Board of Education v. Barnette, Tinker v. Des Moines Independent Community School District, Bethel School District No. 403 v. Fraser, Hazelwood School District v. Kuhlmeier, and Morse v. Frederick. This research project also examines how legal analysts are currently interpreting the issue of school punishment of off-campus online speech to determine how they recommend courts proceed in such cases. Through review of both precedent and law review articles, it examines two branches of legal thought that underlie the issue: what role courts see schools playing in the education of students as citizens and how far courts are willing to go in extending schools’ “in loco parentis” role to off-campus speech. It also reports on societal issues underlying student speech on social media: how social media users can create “community” online and how teens spend their time online. Because legal research carries with it the tradition of offering guidance to judges on how to rule in a particular area, this dissertation concludes with a proposal for how courts, including the U.S. Supreme Court, should rule in cases involving student speech that is critical of school officials or school policy to grant students complete First Amendment protection for all off-campus online speech that does not threaten the school community with violence or libel anyone, whether school official or student

Factors Influencing Consumer Bidding Behavior in Online Auction (Consumer-to-Consumer)

According to the critical analysis of theoretical and empirical literature, there is a need to better understand and to examine the relationship between consumer bidding behavior in online auctions and the related influencing factors. Online auction is a relatively new field of study. It is important to further research the area of online auctions. The theoretical structure, research questions, research hypotheses, and the hypothesized research model are introduced. Theory of Reasoned Auction, Theory of Planned Behavior, and Technology Acceptance Model are used as theoretical foundations of this study. This study focuses on the relationship between consumer bidding behaviors in online auctions, and factors influencing those behaviors. The research is focused on the following influencing factors: customer satisfaction, ease of use of the web site, and demographic profile. A non-experimental, quantitative, correlational research design was conducted to study the relationship between influencing factors and consumer bidding behavior. The target population was people with online shopping experience with eBay who have current access to the Internet. After IRB approval, the researcher collected the date by a paper and pen questionnaire at a public beach in Boca Raton. The questionnaire was handed out to the eligible participants. The questionnaires were dropped in a closed box. The data for this study collected from at least 146 eligible participants using pen and paper questionnaire as an instrument. Findings helped to serve the online consumers and the vendors, as well as being a scholarly contribution to the study of online bidding. This study used SPSS software to analyze the collected data. Descriptive statistics, Cronbach alpha, Pearson r correlation, simple regression, and multiple regressions, were applied in this study. The study findings indicated that an individual\u27s bidding behavior is influenced positively by factors like consumer satisfaction and ease of use and bidding behavior is not influenced by demographic characteristics

Charged-Lepton-Flavour Violation in Kaon Decays in Supersymmetric Theories

We discuss rare kaon decays that violate charged-lepton flavour conservation in supersymmetric theories with and without R parity, in view of possible experiments using an intense proton source as envisaged for a neutrino factory. In the Minimal Supersymmetric Standard Model, such decays are generated by box diagrams involving charginos and neutralinos, but the limits from \mu -> e \gamma, \mu-e conversion and \Delta m_K constrain the branching ratios to challengingly small values. However, this is no longer the case in R-violating theories, where such decays may occur at tree level at rates close to the present experimental limits. Within this framework, we obtain bounds on products of LL\bar{E} and LQ\bar{D} operators from the experimental upper limits on K^0 -> \mu^\pm e^\mp and K^{\pm,0} -> \pi^{\pm,0} \mu^\pm e^\mp decays. We also note the possibility of like-sign lepton decays K^\pm -> \pi^\mp \ell^\pm \ell^\pm in the presence of non-zero \tilde{b}_L-\tilde{b}_R mixing. We conclude that rare kaon decays violating charged-lepton flavour conservation could be an interesting signature of R violation.Comment: 25 pages, 6 figures, Prepared for the Kaon Physics Working Group as part of the ECFA/CERN study of Neutrino Factory & Muon Storage Rings At CERN. Referencies added, constraints update