442 research outputs found
Development of an Automatic Contextual Agricultural Metadata Collection App
Data is the base of digital agriculture. Farm activities are the metadata for production data that are often recorded manually, hence erroneous and missing data often occur. A metadata collection app for contextual agricultural activities was developed for recording detailed information on who is doing what in which field, when, and how. It was developed for android smartphones and functions as a geofence responsive field recognizer using the GPS location of the app user. It records the accessed crop fields automatically with time and facilitates a rules-driven chatbot with validated options for collecting detailed metadata about the conducted activities in that accessed field. The app was designed as a multiple-user app for multi-crop and multi-field usage and storing collected data in a cloud database. The app automatically records time, location, and operator\u27s name, which reduces the chance of missing data, and the chatbot with validated options reduces errors in recording
Modeling Intake of Grazing Cows Fed Complementary Feeds
A model suitable for predicting intake for grazing or non-grazing dairy cows is presented. The model integrates the potentially intake limiting factors of physical fill, physiological energy demand, wet mass, herbage availability, herbage cover, and grazing time. Integration of these factors with a simple set of linear ration balancing constraints yields a model suitable for predicting supplemental feed requirements as well as potential animal production from a grazed land. The model is semi-theoretical, being descriptive in structure, but containing empirical relationships
Existence of radial stationary solutions for a system in combustion theory
In this paper, we construct radially symmetric solutions of a nonlinear
noncooperative elliptic system derived from a model for flame balls with
radiation losses. This model is based on a one step kinetic reaction and our
system is obtained by approximating the standard Arrehnius law by an ignition
nonlinearity, and by simplifying the term that models radiation. We prove the
existence of 2 solutions using degree theory
Logarithmic diffusion and porous media equations: a unified description
In this work we present the logarithmic diffusion equation as a limit case
when the index that characterizes a nonlinear Fokker-Planck equation, in its
diffusive term, goes to zero. A linear drift and a source term are considered
in this equation. Its solution has a lorentzian form, consequently this
equation characterizes a super diffusion like a L\'evy kind. In addition is
obtained an equation that unifies the porous media and the logarithmic
diffusion equations, including a generalized diffusion equation in fractal
dimension. This unification is performed in the nonextensive thermostatistics
context and increases the possibilities about the description of anomalous
diffusive processes.Comment: 5 pages. To appear in Phys. Rev.
Bile duct involvement by hepatocellular carcinoma: A rare occurrence and poor prognostic indicator in bile duct brushing samples
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153086/1/cncy22185_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153086/2/cncy22185.pd
Spin fluctuations in the quasi-two dimensional Heisenberg ferromagnet GdI_2 studied by Electron Spin Resonance
The spin dynamics of GdI_2 have been investigated by ESR spectroscopy. The
temperature dependences of the resonance field and ESR intensity are well
described by the model for the spin susceptibility proposed by Eremin et al.
[Phys. Rev. B 64, 064425 (2001)]. The temperature dependence of the resonance
linewidth shows a maximum similar to the electrical resistance and is discussed
in terms of scattering processes between conduction electrons and localized
spins.Comment: to be published in PR
Streamer Propagation as a Pattern Formation Problem: Planar Fronts
Streamers often constitute the first stage of dielectric breakdown in strong
electric fields: a nonlinear ionization wave transforms a non-ionized medium
into a weakly ionized nonequilibrium plasma. New understanding of this old
phenomenon can be gained through modern concepts of (interfacial) pattern
formation. As a first step towards an effective interface description, we
determine the front width, solve the selection problem for planar fronts and
calculate their properties. Our results are in good agreement with many
features of recent three-dimensional numerical simulations.Comment: 4 pages, revtex, 3 ps file
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