105,064 research outputs found

    Hadwiger Integration of Random Fields

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    Hadwiger integrals employ the intrinsic volumes as measures for integration of real-valued functions. We provide a formula for the expected values of Hadwiger integrals of Gaussian-related random fields. The expected Hadwiger integrals of random fields are both theoretically interesting and potentially useful in applications such as sensor networks, image processing, and cell dynamics. Furthermore, combining the expected integrals with a functional version of Hadwiger's theorem, we obtain expected values of more general valuations on Gaussian-related random fields

    COBE Observations of the Cosmic Infrared Background

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    The Diffuse InfraRed Background Experiment on COBE measured the total infrared signal seen from space at a distance of 1 astronomical unit from the Sun. Using time variations as the Earth orbits the Sun, it is possible to remove most of the foreground signal produced by the interplanetary dust cloud [zodiacal light]. By correlating the DIRBE signal with the column density of atomic hydrogen measured using the 21 cm line, it is possible to remove most of the foreground signal produced by interstellar dust, although one must still be concerned by dust associated with H_2 (molecular gas) and H II (the warm ionized medium). DIRBE was not able to determine the CIRB in the 5-60 micron wavelength range, but did detect both a far infrared background and a near infrared background. The far infrared background has an integrated intensity of about 34 nW/m^2/sr, while the near infrared and optical extragalactic background has about 59 nW/m^2/sr. The Far InfraRed Absolute Spectrophotometer (FIRAS) on COBE has been used to constrain the long wavelength tail of the far infrared background but a wide range of intensities at 850 microns are compatible with the FIRAS data. Thus the fraction of the CIRB produced by SCUBA sources has large uncertainties in both the numerator and the denominator.Comment: Invited paper presented at the 2nd VERITAS Symposium on TeV Astrophysics of Extragalactic Sources, April 24-26, 2003 at the Adler Planetarium in Chicago. 8 pages LaTeX with 3 embedded figure

    Programmed multiplexing system simultaneously monitors several voltages

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    System consists of digital voltmeter with binary coded decimal output, programmer, multiplexer, and two to six gated digital displays. Maximum number of circuits monitored is determined by digital voltmeter, rate of change of parameter being measured and complexity of multiplexer design

    Newsgroups Float Into Safe Harbor, and Copyright Holders Are Sunk

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    Usenet newsgroups are swiftly becoming a popular vehicle for pirating digital music, movies, books, and other copyrighted works. Meanwhile, courts ignore Usenet’s tremendous potential for copyright infringement. In Ellison v. Robertson, the Ninth Circuit Court of Appeals found that America Online’s Usenet service might qualify for safe harbor under the Digital Millennium Copyright Act. According to the district court below, safe harbor would preclude a finding of secondary copyright infringement against America Online. However, the courts misinterpreted the safe harbor provisions. One safe harbor provision was misapplied and another was ignored altogether. This iBrief critiques the Ellison opinions and analyzes the application of the safe harbor provisions to Usenet operators

    Modelling nominal debt contracts and fixed rate debt

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    We provide a simple model of sticky nominal debt contracts and fixed rate debt that can easily be embedded in a dynamic general equilibrium framework. Once linearized, the debt process increases the order of autoregressive dynamics in the system by one; thus potentially introducing more complex adjustment processes

    The Intersection between Chickering’s Theory and Generation Z Student of Color Activism

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    Student activism is an ever-developing trend on college campuses. The current generation, Generation Z, started college in 2013. Analyzing literature on student development and how it intersects with the student activist identity reveals what institutions can do to further serve students in a generational context. When characteristics of students from Generation Z are given proper attention, campus administrators can better understand student activism as an identity. As current and new generations matriculate through college, institutions need to continuously challenge their processes and recreate equitable and inclusive spaces for their students

    Results of thin-route satellite communication system analyses including estimated service costs

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    A variety of cost and performance tradeoffs are addressed and the preliminary design of a communications satellite system capable of meeting isolated rural users' needs is presented. Small inexpensive rural earth stations are linked via the satellite to a nation wide network of large earth stations which are, in turn, interconnected to the switching exchanges of the conventional telephone network. Optimum earth station EIRP and G/T and satellite transponder power are defined as a function of a wide variety of system options

    DIRBE Minus 2MASS: Confirming the CIRB in 40 New Regions at 2.2 and 3.5 Microns

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    With the release of the 2MASS All-Sky Point Source Catalog, stellar fluxes from 2MASS are used to remove the contribution due to Galactic stars from the intensity measured by DIRBE in 40 new regions in the North and South Galactic polar caps. After subtracting the interplanetary and Galactic foregrounds, a consistent residual intensity of 14.69 +/- 4.49 kJy/sr at 2.2 microns is found. Allowing for a constant calibration factor between the DIRBE 3.5 microns and the 2MASS 2.2 microns fluxes, a similar analysis leaves a residual intensity of 15.62 +/- 3.34 kJy/sr at 3.5 microns. The intercepts of the DIRBE minus 2MASS correlation at 1.25 microns show more scatter and are a smaller fraction of the foreground, leading to a still weak limit on the CIRB of 8.88 +/- 6.26 kJy/sr (1 sigma).Comment: 25 pages LaTeX, 10 figures, 5 tables; Version accepted by the ApJ. Includes minor changes to the text including further discussion of zodiacal light issues and the allowance for variable stars in computing uncertainties in the stellar contribution to the DIRBE intensitie
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