8,004 research outputs found

    Easy on that trigger dad: a study of long term family photo retrieval

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    We examine the effects of new technologies for digital photography on people's longer term storage and access to collections of personal photos. We report an empirical study of parents' ability to retrieve photos related to salient family events from more than a year ago. Performance was relatively poor with people failing to find almost 40% of pictures. We analyze participants' organizational and access strategies to identify reasons for this poor performance. Possible reasons for retrieval failure include: storing too many pictures, rudimentary organization, use of multiple storage systems, failure to maintain collections and participants' false beliefs about their ability to access photos. We conclude by exploring the technical and theoretical implications of these findings

    Sprayer Maintenance Tips for Spring

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    Prior to spring field operations, ensuring your equipment is ready can save valuable time and reduce stress when windows get tight due to weather conditions. The sprayer is a critical piece of equipment in most crop production operations. Ensuring your sprayer is mechanically sound, clean, and properly setup will help ensure quality and timely applications of spring fertilizer and pesticides

    Are You Planting on a Level Playing Field?

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    Springtime on a farm is typically filled with the hustle and bustle of gearing up for planting season. This is the time of year when most farmers focus on de-winterizing the sprayer, changing oil in the tractors and checking the seed meters on the planter. If you use a field cultivator, it is also important to make sure it is properly adjusted to help provide a uniform seedbed for the upcoming planting season. Whether this is the first season or the thirtieth season for the field cultivator, there are a few items to check before making your way to the field this spring. While field cultivators are specifically discussed here, many of these concepts also apply to other spring tillage tools (vertical till equipment, etc.)

    Legally Operating a Drone in the Agriculture Industry

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    Drone activity in agriculture continues to increase, and the aerial imagery generated can provide unique insight throughout the crop production season. Over the past decade the Federal Aviation Administration (FAA) has continued to evolve the requirements for the operation of small unmanned aerial systems (sUAS, UAS, UAV or drones) to create a reasonable legal pathway for use in agriculture

    Deconfinement Phase Transition in Hot and Dense QCD at Large N

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    We conjecture that the confinement- deconfinement phase transition in QCD at large number of colors NN and Nf≪NN_f\ll N at T≠0T\neq 0 and μ≠0\mu\neq 0 is triggered by the drastic change in θ\theta behavior. The conjecture is motivated by the holographic model of QCD where confinement -deconfinement phase transition indeed happens precisely at T=TcT=T_c where θ\theta dependence experiences a sudden change in behavior. The conjecture is also supported by quantum field theory arguments when the instanton calculations (which trigger the θ\theta dependence) are under complete theoretical control for T>TcT>T_c, suddenly break down immediately below T<TcT<T_c with sharp changes in the θ\theta dependence. Finally, the conjecture is supported by a number of numerical lattice results. We employ this conjecture to study confinement -deconfinement phase transition of hot and dense QCD in large NN limit by analyzing the θ\theta dependence. We estimate the critical values for TcT_c and μc\mu_c where the phase transition happens by approaching the critical values from the hot and/or dense regions where the instanton calculations are under complete theoretical control. We also describe some defects of various codimensions within a holographic model of QCD by focusing on their role around the phase transition point.Comment: Talk at the Workshop honoring 60th anniversary of Misha Shifma

    Slow Dynamics in Glasses

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    Minimalist theories of complex systems are broadly of two kinds: mean-field and axiomatic. So far all theories of complex properties absent from simple systems and intrinsic to glasses are axiomatic. Stretched Exponential Relaxation (SER) is the prototypical complex temporal property of glasses, discovered by Kohlrausch 150 years ago, and now observed almost universally in microscopically homogeneous, complex non-equilibrium materials, including luminescent electronic (Coulomb) glasses. Critical comparison of alternative axiomatic theories with both numerical simulations and experiments strongly favors dynamical trap models over static percolative or energy landscape models. PACS: 61.20.Lc; 67.40.F

    Generalized Paraxial Ray Trace Procedure Derived from Geodesic Deviation

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    Paraxial ray tracing procedures have become widely accepted techniques for acoustic models in seismology and underwater acoustics. To date a generic form of these procedures including fluid motion and time dependence has not appeared in the literature. A detailed investigation of the characteristic curves of the equations of hydrodynamics allows for an immediate generalization of the procedure to be extracted from the equation form geodesic deviation. The general paraxial ray trace equations serve as an ideal supplement to ordinary ray tracing in predicting the deformation of acoustic beams in random environments. The general procedure is derived in terms of affine parameterization and in a coordinate time parameterization ideal for application to physical acoustic ray propagation. The formalism is applied to layered media, where the deviation equation reduces to a second order differential equation for a single field with a general solution in terms of a depth integral along the ray path. Some features are illustrated through special cases which lead to exact solutions in terms of either ordinary or special functions.Comment: Original; 40 pages (double spaced), 1 figure Replaced version; 36 pages single spaced, 7 figures. Expanded content; Complete derivation of the equations from the equations of hydrodynamics, introduction of an auxiliary basis for three dimensional wave-front modeling. Typos in text and equations correcte

    Universality and Clustering in 1+1 Dimensional Superstring-Bit Models

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    We construct a 1+1 dimensional superstring-bit model for D=3 Type IIB superstring. This low dimension model escapes the problems encountered in higher dimension models: (1) It possesses full Galilean supersymmetry; (2) For noninteracting polymers of bits, the exactly soluble linear superpotential describing bit interactions is in a large universality class of superpotentials which includes ones bounded at spatial infinity; (3) The latter are used to construct a superstring-bit model with the clustering properties needed to define an SS-matrix for closed polymers of superstring-bits.Comment: 11 pages, Latex documen

    P. I. Degrees and prime ideals

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    Cinematic and aesthetic cartographies of subjective mutation

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    This article exmaines the use of cinema as a mapping of subjective mutation in the work of Deleuze, Gauttari and Berardi. Drawing on Deleuze's distinciton between the reduction of the art-work to the symptom and the idea of art as symptomatology, the article focuses on Berardi's use of cinematic examples, posing the quesiton in each case of to what extent they function as symptomatologies or mere symptoms of cultural and subjective mutations in examples ranging from Bergman's Persona to Van Sant's Elephant to finish on speculations about Fincher's The Social Network as a cirtical engagement with subjective mutation in the 21st Century
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