272 research outputs found

    Media-Rich Input Application Liability

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    Until recently, media-rich online interactions were mostly unidirectional: multimedia content was delivered by the service provider to the user. Input from the user came almost exclusively in the form of text. Even when searching the Internet for images or audio, a user typically entered text into a search engine. In addition, search engines indexed multimedia content by analyzing not the content itself but the text surrounding it. This is rapidly changing. With the rise of multimedia-capable smartphones and wireless broadband, applications that allow users to search using non-textual inputs are quickly becoming popular. These applications go much further than simply allowing content to be uploaded and shared, which is already common to Web 2.0 applications; they actually respond to the user based on the input media.[...] These applications represent a new and growing category that I term media-rich input applications (MRIAs).[...] There are three unique attributes of MRIAs that differentiate them from legacy web behavior and therefore require new analysis. First, unlike legacy search applications in which the service provider makes a copy and presents it to the user, MRIA behavior requires the user to make a copy and present it to the service provider. Thus, the image of the book cover in the previous example is digitized by the user and sent to Google; it is not copied by Google and sent to the user in response to a search. Second, the copied content is not necessarily from the Internet; in our example it is from a physical book. Third, some of these technologies create derivative works in a way that simple web searching and indexing does not. This Essay examines how these unique features of MRIAs interact with current copyright doctrine and how the lack of protection for users may discourage innovation by developers of this new and exciting technology. This Essay also proposes a new user safe harbor that balances the interests of users in using MRIAs with the interests of copyright owners in protecting their exclusive rights

    Raman study of the Verwey transition in Magnetite at high-pressure and low-temperature; effect of Al doping

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    We report high-pressure low-temperature Raman studies of the Verwey transition in pure and Al-doped magnetite (Fe_3O_4). The low temperature phase of magnetite displays a number of additional Raman modes that serve as transition markers. These transition markers allow one to investigate the effect of hydrostatic pressure on the Verwey transition temperature. Al-doped magnetite Fe_2.8Al_0.2O_4 (TV=116.5K) displays a nearly linear decrease of the transition temperature with an increase of pressure yielding dP/dT_V = -0.096 GPa/K. In contrast pure magnetite displays a significantly steeper slope of the PT equilibrium line with dP/dT_V = -0.18 GPa/K. The slope of the PT equilibrium lines is related to the changes of the molar entropy and molar volume at the transition. We compare our spectroscopic data with that obtained from the ambient pressure specific heat measurements and find a good agreement in the optimally doped magnetite. Our data indicates that Al doping leads to a smaller entropy change and larger volume expansion at the transition. Our data displays the trends that are consistent with the mean field model of the transition that assumes charge ordering in magnetite.Comment: 17 pages, 3 figure

    No alignment of cattle along geomagnetic field lines found

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    This paper presents a study of the body orientation of domestic cattle on free pastures in several European states, based on Google satellite photographs. In sum, 232 herds with 3412 individuals were evaluated. Two independent groups participated in our study and came to the same conclusion that, in contradiction to the recent findings of other researchers, no alignment of the animals and of their herds along geomagnetic field lines could be found. Several possible reasons for this discrepancy should be taken into account: poor quality of Google satellite photographs, difficulties in determining the body axis, selection of herds or animals within herds, lack of blinding in the evaluation, possible subconscious bias, and, most importantly, high sensitivity of the calculated main directions of the Rayleigh vectors to some kind of bias or to some overlooked or ignored confounder. This factor could easily have led to an unsubstantiated positive conclusion about the existence of magnetoreception.Comment: Added electronic supplement with source dat

    Comparison of 3-, 5-, and 6-Phase Machines for Automotive Charging Applications

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    In this paper, the performance of a 5-phase claw-pole machine/converter system is compared with those of 3-phase and 6-phase systems of the same volume. It is shown that the acoustic output of the 5-phase machine compares favorably with that of the 6-phase machine and is much lower than that of the 3-phase machine over a majority of the operating range. In addition, the output current produced by the 5-phase machine Is, in general, 6-8% higher than those of the 3-phase and 6-phase machines. These results suggest that for maximizing power density while minimizing cost and acoustic noise, 5-phase machines provide a competitive alternative to 6-phase machines of identical volume

    Incorporating the Effects of Magnetic Saturation in a Coupled-Circuit Model of a Claw-Pole Alternator

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    A method of representing the effects of magnetic saturation in a coupled-circuit model of a claw-pole alternator is presented. In the approach considered, the airgap flux density produced by each winding is expressed as a function of magnetic operating point. A challenge in the implementation is that the airgap flux densities consist of several significant harmonics, each of which changes at a distinct rate as iron saturates. Despite this complication, it is shown that relatively simple measurements can be used to determine model parameters. The model is implemented in the analysis of several alternator/rectifier systems using a commercial state-model-based circuit analysis program. Comparisons with experimental results over a wide range of speeds and operating conditions demonstrate its accuracy in predicting both the steady state and transient behavior of the systems

    A medium voltage DC testbed for ship power system research

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    Medium voltage dc distribution systems are currently of interest for future naval warships. In order to provide hardware validation for research associated with the development of these systems, a low power Medium Voltage DC Testbed (MVDCT) is being constructed. This paper documents the system being constructed and provides some initial test results

    Magnetic Properties of MBE Grown La0.6Sr0.4MnO3 Thin Films

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    Honorable Mention Winner This project investigates the magnetic properties of a La1-xSrxMnO3 (x = 0.40) sample of high quality. This sample was grown one atomic layer at a time by Prof. Warusawithana using UNF’s Molecular Beam Epitaxy (MBE) machine. These magnetic properties are investigated over a range of temperatures from 5 to 400 K in fields up to 7 T. We make use of the techniques to analyze the sample to determine to a high degree of precision the critical temperature of the sample, we determined it to be 252 K. We further identified the saturated magnetization, remnant magnetization, and coercive field at 5 K to be 0.00733 emu/g, 0.00563 emu/g and 0.0090 T respectivel

    Analytical Derivation of a Coupled-circuit Model of a Claw-pole Alternator with Concentrated Stator Windings

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    A lumped-parameter coupled-circuit model of a claw-pole alternator is derived. To derive the model, analytical techniques are used to define a three-dimensional (3-D) Fourier-series representation of the airgap flux density. Included in the series expansion are the harmonics introduced by rotor saliency, concentrated stator windings, and stator slots. From the airgap flux density waveform, relatively simple closed-form expressions for the stator and rotor self- and mutual-inductances are obtained. The coupled-circuit model is implemented in the simulation of an alternator/rectifier system using a commercial state-model-based circuit analysis program. Comparisons with experimental results demonstrate the accuracy of the model in predicting both the steady-state and transient behavior of the machin
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