48 research outputs found

    A 1.2V 10μW NPN-Based Temperature Sensor in 65nm CMOS with an inaccuracy of ±0.2°C (3s) from −70°C to 125°C

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    This paper describes a temperature sensor realized in a 65nm CMOS process with a batch-calibrated inaccuracy of ±0.5°C (3σ) and a trimmed inaccuracy of ±0.2°C (3σ) from –70°C to 125°C. This represents a 10-fold improvement in accuracy compared to other deep-submicron temperature sensors [1,2], and is comparable with that of state-of-the-art sensors implemented in larger-featuresize processes [3,4]. The sensor draws 8.3μA from a 1.2V supply and occupies an area of 0.1mm2, which is 45 times less than that of sensors with comparable accuracy [3,4]. These advances are enabled by the use of NPN transistors as sensing elements, the use of dynamic techniques i.e. correlated double sampling (CDS) and dynamic element matching (DEM), and a single room-temperature trim

    A 2.4GHz 830pJ/bit duty-cycled wake-up receiver with −82dBm sensitivity for crystal-less wireless sensor nodes

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    A 65 nm CMOS 2.4 GHz wake-up receiver operating with low-accuracy frequency references has been realized. Robustness to frequency inaccuracy is achieved by employing non-coherent energy detection, broadband-IF heterodyne architecture and impulse-radio modulation. The radio dissipates 415 ¿W at 500 kb/s and achieves a sensitivity of -82 dBm with an energy efficiency of 830 pJ/bit.\u

    FINGERPRINT BASED STUDENT ATTENDANCE MANAGEMENT SYSTEM WITH AUTOMATIC EXCEL COMPUTATION

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    Fingerprint is considered to be the best and most widely used biometrics recognition and verification pattern due its uniqueness for every individual. This study focused on the development of a fingerprint students’ attendance system carried out to curb the problems associated with manual methods of taking students attendance in institutions. The design was carried out using appropriate mathematical model, formulae and block diagram representation while Proteus software simulator was used to simulate functionality of the designed circuit. An attendance algorithm was developed and implemented using coolTerm software and Excel spreadsheet. The system was tested using 15 students’ fingerprints which involves enrollment, authentication and report generation processes. Each student was enrolled with a unique identification. During verification and attendance capture at different times, the system exhibits extremely low (0%) False Acceptance Rate (FAR), extremely high (100%) True Accept Rate (TAR) and extremely low (0%) False Reject Rate (FRR). This study has established the effectiveness of students attendance capture using fingerprint as a more secure, credible and error free to impersonation and buddy punching as associated with the existing manual-paper based system

    Impulse-Based Scheme for Crystal-Less ULP Radios

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    Culture Matters in Communicating the Global Response to COVID-19.

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    Current communication messages in the COVID-19 pandemic tend to focus more on individual risks than community risks resulting from existing inequities. Culture is central to an effective community-engaged public health communication to reduce collective risks. In this commentary, we discuss the importance of culture in unpacking messages that may be the same globally (physical/social distancing) yet different across cultures and communities (individualist versus collectivist). Structural inequity continues to fuel the disproportionate impact of COVID-19 on black and brown communities nationally and globally. PEN-3 offers a cultural framework for a community-engaged global communication response to COVID-19

    Pediatric Bacterial Meningitis Surveillance in Nigeria From 2010 to 2016, Prior to and During the Phased Introduction of the 10-Valent Pneumococcal Conjugate Vaccine.

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    BACKGROUND: Historically, Nigeria has experienced large bacterial meningitis outbreaks with high mortality in children. Streptococcus pneumoniae (pneumococcus), Neisseria meningitidis (meningococcus), and Haemophilus influenzae are major causes of this invasive disease. In collaboration with the World Health Organization, we conducted longitudinal surveillance in sentinel hospitals within Nigeria to establish the burden of pediatric bacterial meningitis (PBM). METHODS: From 2010 to 2016, cerebrospinal fluid was collected from children <5 years of age, admitted to 5 sentinel hospitals in 5 Nigerian states. Microbiological and latex agglutination techniques were performed to detect the presence of pneumococcus, meningococcus, and H. influenzae. Species-specific polymerase chain reaction and serotyping/grouping were conducted to determine specific causative agents of PBM. RESULTS: A total of 5134 children with suspected meningitis were enrolled at the participating hospitals; of these 153 (2.9%) were confirmed PBM cases. The mortality rate for those infected was 15.0% (23/153). The dominant pathogen was pneumococcus (46.4%: 71/153) followed by meningococcus (34.6%: 53/153) and H. influenzae (19.0%: 29/153). Nearly half the pneumococcal meningitis cases successfully serotyped (46.4%: 13/28) were caused by serotypes that are included in the 10-valent pneumococcal conjugate vaccine. The most prevalent meningococcal and H. influenzae strains were serogroup W and serotype b, respectively. CONCLUSIONS: Vaccine-type bacterial meningitis continues to be common among children <5 years in Nigeria. Challenges with vaccine introduction and coverage may explain some of these finding. Continued surveillance is needed to determine the distribution of serotypes/groups of meningeal pathogens across Nigeria and help inform and sustain vaccination policies in the country

    A BJT-Based Temperature-to-Digital Converter With a 0.25 C 3 σ\sigma -Inaccuracy From-40 C to 180 C Using Heater-Assisted Voltage Calibration

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    This article presents a BJT-based temperature-to-digital-converter (TDC) that achieves ±0.25 °C 3 sigma -inaccuracy from -40 °C to +180 °C after a heater-assisted voltage calibration (HA-VCAL). Its switched-capacitor (SC) ADC employs two sampling capacitors and, thus, the minimum number of critical sampling switches, which minimizes the effects of switch leakage at high temperatures and improves accuracy. The TDC is also equipped with an on-chip heater, with which the sensing BJTs can be rapidly (&lt;0.5 s) heated to about 110 °C. This, in turn, enables VCAL at two different temperatures without the need for a temperature-controlled environment. Realized in a 0.16- mu text {m} standard CMOS, the TDC, including the on-chip heater, occupies 0.15 mm2 and operates from 1.8 V.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic

    A Hybrid ADC for High Resolution: The Zoom ADC

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    This paper presents a dynamic zoom ADC for audio applications. It achieves 109-dB DR, 106-dB SNR, and 103-dB SNDR in a 20-kHz bandwidth, while dissipating 1.12 mW and occupying only 0.16 mm2 in 0.16-μm CMOS. This translates to state-of-the-art energy and area efficiency. In this paper, the system- and circuit-level design of the ADC will be presented

    Detection accuracy for evaluating compositional explanations of units

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    The recent success of deep learning models in solving complex problems and in different domains has increased interest in understanding what they learn. Therefore, different approaches have been employed to explain these models, one of which uses human-understandable concepts as explanations. Two examples of methods that use this approach are Network Dissection and Compositional explanations. The former explains units using atomic concepts, while the latter makes explanations more expressive, replacing atomic concepts with logical forms. While intuitively, logical forms are more informative than atomic concepts, it is not clear how to quantify this improvement, and their evaluation is often based on the same metric that is optimized during the search process and on the usage of hyper-parameters to be tuned. In this paper, we propose to use as an evaluation metric the Detection Accuracy, which measures units’ consistency of detection of their assigned explanations. We show that this metric (1) evaluates explanations of different lengths effectively, (2) can be used as a stopping criterion for the compositional explanation search, eliminating the explanation length hyper-parameter, and (3) exposes new specialized units whose length 1 explanations are the perceptual abstractions of their longer explanations
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