12,284 research outputs found

    Acoustic tamper detection sensor with very low false alarm rate

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    We describe a device designed to detect interference (vandalism or tampering) by acoustic means. The design employs both a piezoelectric vibration transducer and a common microphone in a novel mechanical arrangement. In contrast to conventional acoustic sensors that simply respond to vibrations above a threshold, this design analyses the outputs of the two to trigger an alarm. The method confers a near-zero susceptibility to triggering by external loud noises. No complex calculations are required so that only a low-cost, embedded microcontroller is required and the whole sensor can be very cheap. Extreme sensitivity can be achieved with little risk of false alarms

    Primordial Gravitational Waves and Cosmology

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    The observation of primordial gravitational waves could provide a new and unique window on the earliest moments in the history of the universe, and on possible new physics at energies many orders of magnitude beyond those accessible at particle accelerators. Such waves might be detectable soon in current or planned satellite experiments that will probe for characteristic imprints in the polarization of the cosmic microwave background (CMB), or later with direct space-based interferometers. A positive detection could provide definitive evidence for Inflation in the early universe, and would constrain new physics from the Grand Unification scale to the Planck scale.Comment: 12 pages. 4 figure

    Technological change, financial innovation, and diffusion in banking

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    This paper discusses the technological change and financial innovation that commercial banking has experienced during the past twenty-five years. The paper first describes the role of the financial system in economies and how technological change and financial innovation can improve social welfare. We then survey the literature relating to several specific financial innovations, which we define as new products or services, production processes, or organizational forms. We find that the past quarter century has been a period of substantial change in terms of banking products, services, and production technologies. Moreover, while much effort has been devoted to understanding the characteristics of users and adopters of financial innovations and the attendant welfare implications, we still know little about how and why financial innovations are initially developed.Technological innovations
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