Using life-cycle costing and the strategic profit model to enhance motor carrier capital equipment management

Participants in the increasingly competitive motor carrier industry are constantly trying to identify ways to enhance customer service levels and/or reduce costs. This research summarized case-based data from three large carriers to examine the use of life-cycle costing as a method to enhance motor carrier equipment management. The financial results of applying the technique are then examined by applying the Strategic Profit Model

Lowering IceCube's energy threshold for point source searches in the Southern Sky

Observation of a point source of astrophysical neutrinos would be a "smoking gun" signature of a cosmic-ray accelerator. While IceCube has recently discovered a diffuse flux of astrophysical neutrinos, no localized point source has been observed. Previous IceCube searches for point sources in the southern sky were restricted by either an energy threshold above a few hundred TeV or poor neutrino angular resolution. Here we present a search for southern sky point sources with greatly improved sensitivities to neutrinos with energies below 100 TeV. By selecting charged-current ν μ interacting inside the detector, we reduce the atmospheric background while retaining efficiency for astrophysical neutrino-induced events reconstructed with sub-degree angular resolution. The new event sample covers three years of detector data and leads to a factor of 10 improvement in sensitivity to point sources emitting below 100 TeV in the southern sky. No statistically significant evidence of point sources was found, and upper limits are set on neutrino emission from individual sources. A posteriori analysis of the highest-energy (~100 TeV) starting event in the sample found that this event alone represents a 2.8σ deviation from the hypothesis that the data consists only of atmospheric background.Fil: Aartsen, M. G.. University of Adelaide; AustraliaFil: Abraham, K.. Technische Universität München; AlemaniaFil: Ackermann, M.. Deutsches Elektronen-Synchrotron; AlemaniaFil: Adams, J.. University Of Canterbury; Nueva ZelandaFil: Aguilar, J. A.. Université Libre de Bruxelles; BélgicaFil: Golup, Geraldina Tamara. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Wallace, A.. University of Adelaide; AustraliaFil: Wallraff, M.. Rwth Aachen University; AlemaniaFil: Wandkowsky, N.. University of Wisconsin; Estados UnidosFil: Weaver, Ch.. University of Alberta; CanadáFil: Wendt, C.. University of Wisconsin; Estados UnidosFil: Westerhoff, S.. University of Wisconsin; Estados UnidosFil: Whelan, B. J.. University of Adelaide; AustraliaFil: Whitehorn, N.. University of California at Berkeley; Estados UnidosFil: Wickmann, S.. Rwth Aachen University; AlemaniaFil: Wiebe, K.. Johannes Gutenberg Universitat Mainz; AlemaniaFil: Wiebusch, C. H.. Rwth Aachen University; AlemaniaFil: Wille, L.. University of Wisconsin; Estados UnidosFil: Williams, D. R.. University of Alabama at Birmingahm; Estados UnidosFil: Wills, L.. Drexel University; Estados UnidosFil: Wissing, H.. University of Maryland; Estados UnidosFil: Wolf, M.. Stockholms Universitet; SueciaFil: Wood, T. R.. University of Alberta; CanadáFil: Woschnagg, K.. University of California at Berkeley; Estados UnidosFil: Xu, D. L.. University of Wisconsin; Estados UnidosFil: Xu, X. W.. Southern University; Estados UnidosFil: Xu, Y.. Stony Brook University; Estados UnidosFil: Yanez, J. P.. Deutsches Elektronen-Synchrotron; AlemaniaFil: Yodh, G.. University of California at Irvine; Estados UnidosFil: Yoshida, S.. Chiba University; JapónFil: Zoll, M.. Stockholms Universitet; Sueci

Projective dynamics and classical gravitation

Given a real vector space V of finite dimension, together with a particular homogeneous field of bivectors that we call a "field of projective forces", we define a law of dynamics such that the position of the particle is a "ray" i.e. a half-line drawn from the origin of V. The impulsion is a bivector whose support is a 2-plane containing the ray. Throwing the particle with a given initial impulsion defines a projective trajectory. It is a curve in the space of rays S(V), together with an impulsion attached to each ray. In the simplest example where the force is identically zero, the curve is a straight line and the impulsion a constant bivector. A striking feature of projective dynamics appears: the trajectories are not parameterized. Among the projective force fields corresponding to a central force, the one defining the Kepler problem is simpler than those corresponding to other homogeneities. Here the thrown ray describes a quadratic cone whose section by a hyperplane corresponds to a Keplerian conic. An original point of view on the hidden symmetries of the Kepler problem emerges, and clarifies some remarks due to Halphen and Appell. We also get the unexpected conclusion that there exists a notion of divergence-free field of projective forces if and only if dim V=4. No metric is involved in the axioms of projective dynamics.Comment: 20 pages, 4 figure

Rapid and High-Throughput pan-Orthopoxvirus Detection and Identification using PCR and Mass Spectrometry

The genus Orthopoxvirus contains several species of related viruses, including the causative agent of smallpox (Variola virus). In addition to smallpox, several other members of the genus are capable of causing human infection, including monkeypox, cowpox, and other zoonotic rodent-borne poxviruses. Therefore, a single assay that can accurately identify all orthopoxviruses could provide a valuable tool for rapid broad orthopovirus identification. We have developed a pan-Orthopoxvirus assay for identification of all members of the genus based on four PCR reactions targeting Orthopoxvirus DNA and RNA helicase and polymerase genes. The amplicons are detected using electrospray ionization-mass spectrometry (PCR/ESI-MS) on the Ibis T5000 system. We demonstrate that the assay can detect and identify a diverse collection of orthopoxviruses, provide sub-species information and characterize viruses from the blood of rabbitpox infected rabbits. The assay is sensitive at the stochastic limit of PCR and detected virus in blood containing approximately six plaque-forming units per milliliter from a rabbitpox virus-infected rabbit

A combined maximum-likelihood analysis of the high-energy astrophysical neutrino flux measured with IceCube

Evidence for an extraterrestrial flux of high-energy neutrinos has now been found in multiple searches with the IceCube detector. The first solid evidence was provided by a search for neutrino events with deposited energies $\gtrsim30$ TeV and interaction vertices inside the instrumented volume. Recent analyses suggest that the extraterrestrial flux extends to lower energies and is also visible with throughgoing, $\nu_\mu$-induced tracks from the Northern hemisphere. Here, we combine the results from six different IceCube searches for astrophysical neutrinos in a maximum-likelihood analysis. The combined event sample features high-statistics samples of shower-like and track-like events. The data are fit in up to three observables: energy, zenith angle and event topology. Assuming the astrophysical neutrino flux to be isotropic and to consist of equal flavors at Earth, the all-flavor spectrum with neutrino energies between 25 TeV and 2.8 PeV is well described by an unbroken power law with best-fit spectral index $-2.50\pm0.09$ and a flux at 100 TeV of $\left(6.7_{-1.2}^{+1.1}\right)\cdot10^{-18}\,\mathrm{GeV}^{-1}\mathrm{s}^{-1}\mathrm{sr}^{-1}\mathrm{cm}^{-2}$. Under the same assumptions, an unbroken power law with index $-2$ is disfavored with a significance of 3.8 $\sigma$ ($p=0.0066\%$) with respect to the best fit. This significance is reduced to 2.1 $\sigma$ ($p=1.7\%$) if instead we compare the best fit to a spectrum with index $-2$ that has an exponential cut-off at high energies. Allowing the electron neutrino flux to deviate from the other two flavors, we find a $\nu_e$ fraction of $0.18\pm0.11$ at Earth. The sole production of electron neutrinos, which would be characteristic of neutron-decay dominated sources, is rejected with a significance of 3.6 $\sigma$ ($p=0.014\%$).Comment: 16 pages, 10 figures; accepted for publication in The Astrophysical Journal; updated one referenc

Measurement of the Atmospheric νe\nu_e Spectrum with IceCube

We present a measurement of the atmospheric $\nu_e$ spectrum at energies between 0.1 TeV and 100 TeV using data from the first year of the complete IceCube detector. Atmospheric $\nu_e$ originate mainly from the decays of kaons produced in cosmic-ray air showers. This analysis selects 1078 fully contained events in 332 days of livetime, then identifies those consistent with particle showers. A likelihood analysis with improved event selection extends our previous measurement of the conventional $\nu_e$ fluxes to higher energies. The data constrain the conventional $\nu_e$ flux to be $1.3^{+0.4}_{-0.3}$ times a baseline prediction from a Honda's calculation, including the knee of the cosmic-ray spectrum. A fit to the kaon contribution ($\xi$) to the neutrino flux finds a kaon component that is $\xi =1.3^{+0.5}_{-0.4}$ times the baseline value. The fitted/measured prompt neutrino flux from charmed hadron decays strongly depends on the assumed astrophysical flux and shape. If the astrophysical component follows a power law, the result for the prompt flux is $0.0^{+3.0}_{-0.0}$ times a calculated flux based on the work by Enberg, Reno and Sarcevic.Comment: PRD accepted versio