University of Alabama

About: University of Alabama is a education organization based out in Tuscaloosa, Alabama, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 27323 authors who have published 48609 publications receiving 1565337 citations. The organization is also known as: Alabama & Bama.

An effective key management scheme for heterogeneous sensor networks

Abstract: Security is critical for sensor networks used in military, homeland security and other hostile environments. Previous research on sensor network security mainly considers homogeneous sensor networks. Research has shown that homogeneous ad hoc networks have poor performance and scalability. Furthermore, many security schemes designed for homogeneous sensor networks suffer from high communication overhead, computation overhead, and/or high storage requirement. Recently deployed sensor network systems are increasingly following heterogeneous designs. Key management is an essential cryptographic primitive to provide other security operations. In this paper, we present an effective key management scheme that takes advantage of the powerful high-end sensors in heterogeneous sensor networks. The performance evaluation and security analysis show that the key management scheme provides better security with low complexity and significant reduction on storage requirement, compared with existing key management schemes.

The next generation of moderator research in personality psychology.

Abstract: The concept of a moderator variable has a long and checkered history in personality psychology. In this article I review the methodological and conceptual advances in recent moderator variable research. I then report the results of a number of empirical analyses of three newly proposed idiographic moderator variables: scalability, metatraits, and construct similarity, as well as the ipsatized variance index. The results of these analyses indicate that moderator effect sizes in personality can be expected to correspond to a correlation of about .10. I then consider two recent prescriptions, (a) aggregating trait-specific moderators into general ones, and (b) evaluating joint (e.g., triple interaction) moderator effects. Following these prescriptions did not increase the size of the moderator effects in these data. I conclude that moderator effects in personality will be small, and will thus be most reliably detected in very large samples with predictors that are strongly related to the criteria. Even small moderator effects can be important and interesting in the context of theory disconfirmation. However, moderator variables generally will not serve to transform weak relations among personality variables into strong ones.

Cooperative Learning, Collaborative Learning, and Interaction: Three Communicative Strands in the Language Classroom

Abstract: This article describes important distinctions among three strands of communication in the foreign or second language (L2) classroom: cooperative learning, collaborative learning, and interaction. These three strands have different connotations, which, when understood, can help us better comprehend language learning and teaching. Cooperative learning refers to a particular set of classroom techniques that foster learner interdependence as a route to cognitive and social development. Collaborative learning has a “social constructivist” philosophical base, which views learning as construction of knowledge within a social context and which therefore encourages acculturation of individuals into a learning community. Interaction is the broadest of the three terms and refers to personal communication, which is facilitated by an understanding of four elements: language tasks, willingness to communicate, style differences, and group dynamics.

Jet energy scale and resolution in the CMS experiment in pp collisions at 8 TeV

Abstract: Improved jet energy scale corrections, based on a data sample corresponding to an integrated luminosity of 19.7 fb^(-1) collected by the CMS experiment in proton-proton collisions at a center-of-mass energy of 8 TeV, are presented. The corrections as a function of pseudorapidity η and transverse momentum p_T are extracted from data and simulated events combining several channels and methods. They account successively for the effects of pileup, uniformity of the detector response, and residual data-simulation jet energy scale differences. Further corrections, depending on the jet flavor and distance parameter (jet size) R, are also presented. The jet energy resolution is measured in data and simulated events and is studied as a function of pileup, jet size, and jet flavor. Typical jet energy resolutions at the central rapidities are 15–20% at 30 GeV, about 10% at 100 GeV, and 5% at 1 TeV. The studies exploit events with dijet topology, as well as photon+jet, Z+jet and multijet events. Several new techniques are used to account for the various sources of jet energy scale corrections, and a full set of uncertainties, and their correlations, are provided. The final uncertainties on the jet energy scale are below 3% across the phase space considered by most analyses (p_T > 30 GeV and 0|η| 30 GeV is reached, when excluding the jet flavor uncertainties, which are provided separately for different jet flavors. A new benchmark for jet energy scale determination at hadron colliders is achieved with 0.32% uncertainty for jets with p_T of the order of 165–330 GeV, and |η| < 0.8.

OBSERVATION and CHARACTERIZATION of A COSMIC MUON NEUTRINO FLUX from the NORTHERN HEMISPHERE USING SIX YEARS of ICECUBE DATA

Abstract: The IceCube Collaboration has previously discovered a high-energy astrophysical neutrino flux using neutrino events with interaction vertices contained within the instrumented volume of the IceCube detector. We present a complementary measurement using charged current muon neutrino events where the interaction vertex can be outside this volume. As a consequence of the large muon range the effective area is significantly larger but the field of view is restricted to the Northern Hemisphere. IceCube data from 2009 through 2015 have been analyzed using a likelihood approach based on the reconstructed muon energy and zenith angle. At the highest neutrino energies between 194 TeV and 7.8 PeV a significant astrophysical contribution is observed, excluding a purely atmospheric origin of these events at 5.6s significance. The data are well described by an isotropic, unbroken power-law flux with a normalization at 100 TeV neutrino energy of (0.90 -0.27 +0.30) × 10-18 Gev-1 cm-2 s-1 sr-1and a hard spectral index of γ = 2.13 ± 0.13. The observed spectrum is harder in comparison to previous IceCube analyses with lower energy thresholds which may indicate a break in the astrophysical neutrino spectrum of unknown origin. The highest-energy event observed has a reconstructed muon energy of (4.5 ± 1.2) PeV which implies a probability of less than 0.005% for this event to be of atmospheric origin. Analyzing the arrival directions of all events with reconstructed muon energies above 200 TeV no correlation with known γ-ray sources was found. Using the high statistics of atmospheric neutrinos we report the current best constraints on a prompt atmospheric muon neutrino flux originating from charmed meson decays which is below 1.06 in units of the flux normalization of the model in Enberg et al.