Mobile ad hoc networks will form a critical part of the first-responder communications infrastructure. Empirical data shows how network-aware, autonomous, mobile agents can manage information ...services on live manet environments. A multidisciplinary team in Drexel University's College of Engineering has been working with local law enforcement and transportation officials to identify problems in enabling police, fire, security, and other public protectors to effectively communicate and collaborate in first-response situations. Development of the Philadelphia Area Urban Wireless Network Testbed (PA-UWNT) is part of this effort. The PA-UWNT is a mobile ad hoc network (manet) comprising mobile computers (PDAs, tablets, and laptops) and Web service-based applications. Our experience in the PA-UWNT project indicates that constructing such systems will require new research developments in computer networking, agent and service-based computing, and security that integrate each of these disciplines at several fundamental levels. In this paper, we outline part of this approach through experiments demonstrating the utility of integrating the network and agent layers and enabling agents to reason about the current operating context. We posit that autonomous agents that can reason about the network's slate and services offer an effective means of meeting the manet environment's challenges.
The Cosmic Ray Energetics And Mass (CREAM) instrument is configured with a suite of particle detectors to measure TeV cosmic-ray elemental spectra from protons to iron nuclei over a wide energy ...range. The goal is to extend direct measurements of cosmic-ray composition to the highest energies practical, and thereby have enough overlap with ground based indirect measurements to answer questions on cosmic-ray origin, acceleration and propagation. The balloon-borne CREAM was flown successfully for about 161days in six flights over Antarctica to measure elemental spectra of Z=1–26 nuclei over the energy range 1010 to >1014eV. Transforming the balloon instrument into ISS-CREAM involves identification and replacement of components that would be at risk in the International Space Station (ISS) environment, in addition to assessing safety and mission assurance concerns. The transformation process includes rigorous testing of components to reduce risks and increase survivability on the launch vehicle and operations on the ISS without negatively impacting the heritage of the successful CREAM design. The project status, including results from the ongoing analysis of existing data and, particularly, plans to increase the exposure factor by another order of magnitude utilizing the International Space Station are presented.
We report a study of ν(μ) charged-current quasielastic events in the segmented scintillator inner tracker of the MINERvA experiment running in the NuMI neutrino beam at Fermilab. The events were ...selected by requiring a μ- and low calorimetric recoil energy separated from the interaction vertex. We measure the flux-averaged differential cross section, dσ/dQ², and study the low energy particle content of the final state. Deviations are found between the measured dσ/dQ² and the expectations of a model of independent nucleons in a relativistic Fermi gas. We also observe an excess of energy near the vertex consistent with multiple protons in the final state.
We have isolated ν(μ) charged-current quasielastic (QE) interactions occurring in the segmented scintillator tracking region of the MINERvA detector running in the NuMI neutrino beam at Fermilab. We ...measure the flux-averaged differential cross section, dσ/dQ², and compare to several theoretical models of QE scattering. Good agreement is obtained with a model where the nucleon axial mass, M(A), is set to 0.99 GeV/c² but the nucleon vector form factors are modified to account for the observed enhancement, relative to the free nucleon case, of the cross section for the exchange of transversely polarized photons in electron-nucleus scattering. Our data at higher Q² favor this interpretation over an alternative in which the axial mass is increased.
This paper investigates the use of conversational agents to scaffold online collaborative learning discussions through an approach called academically productive talk (APT). In contrast to past work ...on dynamic support for collaborative learning, which has involved using agents to elevate the conceptual depth of collaborative discussion by leading students in groups through directed lines of reasoning, this APT-based approach lets students follow their own lines of reasoning and promotes productive practices such as explanation of reasoning and refinement of ideas. Two forms of support are contrasted, namely, Revoicing support and Feedback support. The study provides evidence that Revoicing support resulted in significantly more intensive reasoning exchange between students in the chat and significantly more learning during the chat than when that form of support was absent. Another form of support, namely, Feedback support increased expression of reasoning while marginally decreasing the intensity of the interaction between students and did not affect learning.
We measure the top quark mass in dilepton final states of tt¯ events in pp¯ collisions at s=1.96 TeV, using data corresponding to an integrated luminosity of 9.7 fb−1 at the Fermilab Tevatron ...Collider. The analysis features a comprehensive optimization of the neutrino weighting method to minimize the statistical uncertainties. We also improve the calibration of jet energies using the calibration determined in tt¯→lepton+jets events, which reduces the otherwise limiting systematic uncertainty from the jet energy scale. The measured top quark mass is mt=173.32±1.36(stat)±0.85(syst) GeV.
The Cosmic Ray Energetics and Mass experiment at the International Space Station (ISS-CREAM) is developed for studying the origin, acceleration and propagation mechanism of high energy cosmic rays. ...The Top and Bottom Counting Detectors (TCD/BCD), sub-detectors of the ISS-CREAM instrument, are developed for electron/γ-ray physics. The TCD/BCD help distinguish electrons from protons by comparing the hit and shower width distributions for electrons and protons. The e/p separation capability of the TCD/BCD is studied by using the GEANT3 simulation package, and optimal parameters for the e/p separation are obtained.
Electron and photon identification in the D0 experiment Atkins, S.; Avila, C.; Baldin, B. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2014, Letnik:
750
Journal Article
Recenzirano
Odprti dostop
The electron and photon reconstruction and identification algorithms used by the D0 Collaboration at the Fermilab Tevatron collider are described. The determination of the electron energy scale and ...resolution is presented. Studies of the performance of the electron and photon reconstruction and identification are summarized. The results are based on measurements of Z boson decay events of Z→ee and Z→γℓℓ(ℓ=e,μ) collected in pp¯ collisions at a center-of-mass energy of 1.96TeV using an integrated luminosity of up to 10fb−1.
This practical and accessible text for educating students with special needs provides examples and tips on how to develop effective teaching and learning in inclusive settings.
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