1,720,964 research outputs found
A Complete Gas-Sensor array Interface for Wine Quality Monitoring
No full textRecent gas sensors applications (like the wine recognition, for the proposed device) require the development of efficient gas detector systems. A gas-detector system is composed by a sensor module, an electronics read-out (including the heater and the temperature control for themicrosensor substrate) and a post-processing part. These parts are strictly correlated and the improvement of the gas detector performance is achieved by optimizing the system from a top point-of-view. In this work, a complete interface for wine quality monitoring is presented
CMOS single-photon avalanche diode array for time-resolved fluorescence detection
No full textA single photon avalanche diode detector for the analysis of fluorescence phenomena is presented. The 14-pixels array, fabricated in a conventional high voltage 0.35-μm CMOS technology, allows measuring photon densities as low as 108 photons/cm2s. Each 180x150-μm2 pixel integrates a single photon avalanche diode combined with an active quenching circuit and a 17-bit digital events counter. On chip master logic provides the digital control phases required by the pixel array with a full programmability of the main timing synchronisms. Time-resolved measurements has been demonstrated by detecting a 10ns, 10pW (peak-power on the pixel) light pulse with a typical resolution of 80ps
Single-Photon Avalanche Diode CMOS Sensor for Time-Resolved Fluorescence Measurements
No full textA single-photon avalanche diode-based pixel array for the analysis of fluorescence phenomena is presented. Each 180 times 150 - um2 pixel integrates a single photon detector combined with an active quenching circuit and a 17-bit digital events counter. On-chip master logic provides the digital control phases required by the pixel array with a full programmability of the main timing synchronisms. The pixel exhibits an average dark count rate of 3 kcps and a dynamic range of over 120-dB in time uncorrelated operation. A complete characterization of the single photon avalanche diode characteristics is reported. Time-resolved fluorescence measurements have been demonstrated by detecting the fluorescence decay of quantum-dot samples without the aid of any optical filters for excitation laser light cutoff
A CMOS single-photon avalanche diode sensor for fluorescence lifetime imaging
No full textThis contribute describes the design and preliminary characterization of a 16x16-pixel array based on Single Photon Avalanche Diodes (SPADs), fabricated in a standard high-voltage 0.35μm CMOS technology, and aimed at the analysis of fluorescence phenomena. Each pixel integrates a SPAD combined with an active quenching circuit and a voltage comparator for the digital conversion of the avalanche event. The sensor features a minimum detectable photon density of 108 photons/cm2s, with a maximum dynamic range of over 120dB. Detection of fluorescence light has been demonstrated with a 160ps time resolution over a 100ns observation window
A 160x120-pixel Uncooled IR-FPA Readout Integrated Circuit with On-chip Non-uniformity Compensation
No full textThis paper describes the development of a readout integrated circuit coupled to a 160x120-pixels infrared focal plane array (IR-FPA) based on micro-bolometric detectors. The readout circuit includes 5-bit in-pixel memory and dedicated circuitry for automatic calibration of the array offset non-uniformity, 8 selectable columns of reference pixels, and four high-sensitivity temperature sensors to monitor FPA temperature. The integrated circuit has been fabricated in a standard CMOS 0.5um 2P3M 3.3/5V technology and subsequently processed to build the vanadium oxide bolometers having a pitch of 52um. Electrical and electro-optical tests have been performed: the chip operates at 50fps with NETD=0.33K (dynamic vacuum, optics with F/#=1.2) dissipating 80mW, with up to 32x offset reduction
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“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
Full text linkWe 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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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