1,721,291 research outputs found

    Experimental results of a cascadable micropower time delay estimator

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    Experimental results of a micropower integrated circuit (IC) for the measurement of the relative time delay between two signals are presented. A complete experimental characterisation shows that the IC achieves an accuracy of 3 ms in the whole measurement range with a power consumption of 12 mW. This improves on all low-power designs previously reported in the literature.Fil: Julian, Pedro Marcelo. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; ArgentinaFil: Martin Pirchio, F.N.. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; ArgentinaFil: Andreou, Andreas G.. John Hopkins University; Estados Unido

    VLSI implementation of an energy-aware wake-up detector for an acoustic surveillance sensor network

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    We present a low-power VLSI wake-up detector for a sensor network that uses acoustic signals to localize ground-base vehicles. The detection criterion is the degree of low-frequency periodicity in the acoustic signal, and the periodicity is computed from the "bumpiness" of the autocorrelation of a one-bit version of the signal. We then describe a CMOS ASIC that implements the periodicity estimation algorithm. The ASIC is functional and its core consumes 835 nanowatts. It was integrated into an acoustic enclosure and deployed in field tests with synthesized sounds and ground-based vehicles.Fil: Goldberg, David H.. Johns Hopkins University; Estados UnidosFil: Andreou, Andreas. Johns Hopkins University; Estados UnidosFil: Julian, Pedro Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; ArgentinaFil: Pouliquen, Philippe O.. Johns Hopkins University; Estados UnidosFil: Riddle, Laurence. Signal Systems Corporation; Estados UnidosFil: Rosasco, Rich. Signal Systems Corporation; Estados Unido

    A low-power correlation-derivative CMOS VLSI circuit for bearing estimation

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    We present a CMOS integrated circuit (IC) for bearing estimation in the low-audio range that performs a correlation derivative approach in a 0.35-/spl mu/m technology. The IC calculates the bearing angle of a sound source with a mean variance of one degree in a 360/spl deg/ range using four microphones: one pair is used to produce the indication and the other to define the quadrant. An adaptive algorithm decides which pair to use depending on the direction of the incoming signal, in such a way to obtain the best estimate. The IC contains two blocks with 104 stages each. Every stage has a delay unit, a block to reduce the clock speed, and a 10-bit UP/DN counter. The IC measures 2 mm by 2.4 mm, and dissipates 600 /spl mu/W at 3.3 V and 200 kHz. It is purely digital and uses a one-bit quantization of the input signals.Fil: Julian, Pedro Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; ArgentinaFil: Andreou, Andreas G.. The Johns Hopkins University; Estados UnidosFil: Goldberg, David H.. Cornell University.; Estados Unido

    7 TOPS/W Cellular Neural Network Processor Core for Intelligent Internet-of-Things

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    We discuss the architecture, implementation and testing of a simplicial Cellular Neural Network (CNN) vector processor core aimed at vision oriented intelligent Internet-of-Things (IoT) devices. The architecture comprises a linear array of 64 processing elements (PE), each connected to a 4 neighbor clique operating on 8-bit input and state data. A 3-bit simplicial parameter, allows multilevel function approximation and extends the functionality over previously reported chips. Input data vectors are stored in two 64 x 64 x 8-bit data caches. The chip is synthesized from a custom designed ultra low voltage CMOS library and fabricated in a 55nm CMOS technology. Dynamic voltage/frequency scaling allows operation at power supplies between 0.5 and 1.2 Volts allowing for a tradeoff between speed and power. The fabricated chip achieves an overall performance of 7.05 TOPS/W at 732fps, with a dynamic energy efficiency of 12.2fJ per operation (OP) at 1.2 Volts.Fil: Villemur, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; ArgentinaFil: Julian, Pedro Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; ArgentinaFil: Figliolia, Tomas. University Johns Hopkins; Estados UnidosFil: Andreou, Andreas. University Johns Hopkins; Estados Unido

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    A Comparative Study of Sound Localization Algorithms for Energy Aware Sensor Network Nodes

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    Sound localization using energy-aware hardware for sensor networks nodes is a problem with many applications in surveillance and security. In this paper, we evaluate four algorithms for sound localization using signals recorded in a natural environment with an array of commercial off-the-shelf microelectromechanical systems microphones and a specially designed compact acoustic enclosure. We evaluate performance of the algorithms and their hardware complexity which relates directly to energy consumption.Fil: Julian, Pedro Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. The Johns Hopkins University; Estados Unidos. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; ArgentinaFil: Andreou, Andreas. The Johns Hopkins University; Estados UnidosFil: Riddle, Larry. Signal Systems Corporation; Estados UnidosFil: Shamma, Shihab. University of Maryland; Estados UnidosFil: Goldberg, David H.. The Johns Hopkins University; Estados UnidosFil: Cauwenberghs, Gert. The Johns Hopkins University; Estados Unido

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    Energy aware simplicial processor for embedded morphological visual processing in intelligent internet of things

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    This Letter presents the architecture implementation and testing of an single instruction multiple data (SIMD) processor for energy aware embedded morphological visual processing using the simplicial piece-wise linear approximation. The architecture comprises a linear array of 48 × 48 processing elements, each connected to an eight-neighbour clique operating on binary input and state data. The architecture is synthesised from a custom designed ultra low-voltage CMOS library and fabricated in a 55 nm CMOS technology. The chip is capable of dynamic voltage/frequency scaling with power supplies between 0.5 and 1.2 V. The fabricated chip achieves an overall performance of 293 TOPS/W with dynamic energy dissipation efficiency of 3.4 fJ per output operation at 0.6 V.Fil: Villemur, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; ArgentinaFil: Julian, Pedro Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; ArgentinaFil: Andreou, Andreas. University Johns Hopkins; Estados Unido
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