1,720,956 research outputs found
ASIC Design Techniques and Signal Processing Supporting Power and Area Efficient High Dynamic Range Miniature Capacitive Microphones
No full textMicro Electromechanical System (MEMS) microphones are capacitive sensors used for
audio acquisition. The possibility of integration of the MEMS transducer with the
CMOS read-out interface circuit in the same package, together with the small power
consumption make MEMS microphones ideal for use in portable consumer electronics
such as smartphones, laptops, tablets, headphones and smartwatches. Advanced
features of these devices required by the market, such as noise cancellation and voice
recognition, place increasing demands on performance of the microphones. This PhD
thesis presents techniques to improve the Signal-to-Noise Ratio (SNR) of the interface
circuit for the MEMS transducer.
An electrical model of the MEMS transducer is developed in the first part of the
thesis. This model includes nonlinear effects of the MEMS transducer, such as distortion.
An overview of the interface circuits for MEMS capacitive transducers is reported
in the second part. Direct Current (DC) biased interfaces, namely source followers,
super source followers, common source amplifiers with capacitive feedback, common
source amplifiers with microphone in the feedback, differential amplifiers, differential
difference amplifiers and current feedback amplifiers together with voltage control
Alternating Current (AC) basing and current control AC biasing are compared in
terms of SNR, Acoustic Overload Point (AOP) and current consumption. Flicker noise
is identified as the limiting factor for the SNR and the source follower circuit is chosen
as the best candidate for improvement. In the final part of the thesis, two techniques
to increase the SNR are developed: bulk biasing and dynamic capacitive attenuation.
Circuits exploiting these techniques are introduced and two test-chips are fabricated.
Each of the techniques improves the SNR by several , while AOP is maintained and
power consumption only slightly increased.Micro Electromechanical System (MEMS) microphones are capacitive sensors used for
audio acquisition. The possibility of integration of the MEMS transducer with the
CMOS read-out interface circuit in the same package, together with the small power
consumption make MEMS microphones ideal for use in portable consumer electronics
such as smartphones, laptops, tablets, headphones and smartwatches. Advanced
features of these devices required by the market, such as noise cancellation and voice
recognition, place increasing demands on performance of the microphones. This PhD
thesis presents techniques to improve the Signal-to-Noise Ratio (SNR) of the interface
circuit for the MEMS transducer.
An electrical model of the MEMS transducer is developed in the first part of the
thesis. This model includes nonlinear effects of the MEMS transducer, such as distortion.
An overview of the interface circuits for MEMS capacitive transducers is reported
in the second part. Direct Current (DC) biased interfaces, namely source followers,
super source followers, common source amplifiers with capacitive feedback, common
source amplifiers with microphone in the feedback, differential amplifiers, differential
difference amplifiers and current feedback amplifiers together with voltage control
Alternating Current (AC) basing and current control AC biasing are compared in
terms of SNR, Acoustic Overload Point (AOP) and current consumption. Flicker noise
is identified as the limiting factor for the SNR and the source follower circuit is chosen
as the best candidate for improvement. In the final part of the thesis, two techniques
to increase the SNR are developed: bulk biasing and dynamic capacitive attenuation.
Circuits exploiting these techniques are introduced and two test-chips are fabricated.
Each of the techniques improves the SNR by several , while AOP is maintained and
power consumption only slightly increased
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Propagación de especies nativas de peperomia con potencial ornamental en la provincia de Jujuy (Argentina)
Get PDFPosterEn la Provincia de Jujuy se encuentran 14 especies del genero Peperomia (Piperaceae) que crecen en la provincia fitogeográfica de las Yungas (Zanotii et al., 2012), caracterizada por selvas y bosques de montañas subtropicales. Este género están presente en la producción y comercio como planta de interior a nivel mundial. La domesticación y caracterización de la flora nativa es importante en los programas de fitomejoramiento para desarrollar variedades comerciales (Facciuto et al., 2021).Instituto de FloriculturaFil: Gaspar, Samuel Bernardo. Universidad Nacional de Jujuy. Facultad de Ciencias Agrarias. Centro de Investigaciones y Estudios en Diversidad Vegetal; ArgentinaFil: Facciuto, Gabriela Rosa. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; ArgentinaFil: Romeo, Raquel Angela. Universidad Nacional de Jujuy. Facultad de Ciencias Agrarias. Centro de Investigaciones y Estudios en Diversidad Vegetal; Argentin
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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