143 research outputs found
Focus estimation in academic environments using Computer Vision
In this paper we propose a system capable of monitoring students’ focus through cameras and using Computer Vision algorithms. Experimental results show that our system is capable of identifying students and tracking their focus during a class. At the end of the class, the system outputs graphical feedback to teachers regarding the average level of students’ focus. Moreover, it can identify lecture periods in which students were less watchful and the corresponding topics that potentially need extra focus. In this paper we start by presenting the architecture of the system, followed by results obtained both during a small-group workshop and a classroom with a large number of attending students. The main goal of this work is to contribute to the transformation of the classroom as a sensing environment, providing information to both teachers and students about their engagement during the class.publishe
A Flexible LDPC/Turbo Decoder Architecture
Low-density parity-check (LDPC) codes and convolutional Turbo codes are two of the most powerful error correcting codes that are widely used in modern
communication systems. In a multi-mode baseband receiver, both LDPC and Turbo decoders may be required. However, the different decoding approaches
for LDPC and Turbo codes usually lead to different hardware architectures. In this paper we propose a unified message passing algorithm for LDPC and Turbo
codes and introduce a flexible soft-input soft-output (SISO) module to handle LDPC/Turbo decoding. We employ the trellis-based maximum a posteriori (MAP)
algorithm as a bridge between LDPC and Turbo codes decoding. We view the LDPC code as a concatenation of n super-codes where each super-code has a simpler
trellis structure so that the MAP algorithm can be easily applied to it. We propose a flexible functional unit (FFU) for MAP processing of LDPC and Turbo
codes with a low hardware overhead (about 15% area and timing overhead). Based on the FFU, we propose an area-efficient flexible SISO decoder architecture to
support LDPC/Turbo codes decoding. Multiple such SISO modules can be embedded into a parallel decoder for higher decoding throughput. As a case study, a
flexible LDPC/Turbo decoder has been synthesized on a TSMC 90 nm CMOS technology with a core area of 3.2 mm2. The decoder can support IEEE 802.16e LDPC codes, IEEE 802.11n LDPC codes, and 3GPP LTE Turbo codes. Running at 500 MHz clock frequency, the decoder can sustain up to 600 Mbps LDPC decoding or
450 Mbps Turbo decoding.NokiaNokia Siemens Networks (NSN)XilinxTexas InstrumentsNational Science Foundatio
Monitoring Students’ Attention in a Classroom Through Computer Vision
Monitoring classrooms using cameras is a non-invasive approach of digitizing students’ behaviour. Understanding students’ attention span and what type of behaviours may indicate a lack of attention is fundamental for understanding and consequently improving the dynamics of a lecture. Recent studies show useful information regarding classrooms and their students’ behaviour throughout the lecture. In this paper we start by presenting an overview about the state of the art on this topic, presenting what we consider to be the most robust and efficient Computer Vision techniques for monitoring classrooms. After the analysis of relevant state of the art, we propose an agent that is theoretically capable of tracking the students’ attention and output that data. The main goal of this paper is to contribute to the development of an autonomous agent able to provide information to both teachers and students and we present preliminary results on this topic. We believe this autonomous agent features the best solution for monitoring classrooms since it uses the most suited state of the art approaches for each individual role.Integrated Programme of SR&TD SOCA (Ref. CENTRO-01-0145-FEDER-000010) Centro 2020
program, Portugal 2020, European Union, through the European Regional Development
Fund.publishe
Scintillation particle detection based on microfluidics
A novel type of particle detector based on scintillation, with precise spatial resolution and high radiation hardness, is being studied. It consists of a single microfluidic channel filled with a liquid scintillator and is designed to define an array of scintillating waveguides each independently coupled to a photodetector. Prototype detectors built using an SU-8 epoxy resin have been tested with electrons from a radioactive source. The experimental results show a light yield compatible with the theoretical expectations and confirm the validity of the approach
Local conservation scores without a priori assumptions on neutral substitution rates
<p>Abstract</p> <p>Background</p> <p>Comparative genomics aims to detect signals of evolutionary conservation as an indicator of functional constraint. Surprisingly, results of the ENCODE project revealed that about half of the experimentally verified functional elements found in non-coding DNA were classified as unconstrained by computational predictions. Following this observation, it has been hypothesized that this may be partly explained by biased estimates on neutral evolutionary rates used by existing sequence conservation metrics. All methods we are aware of rely on a comparison with the neutral rate and conservation is estimated by measuring the deviation of a particular genomic region from this rate. Consequently, it is a reasonable assumption that inaccurate neutral rate estimates may lead to biased conservation and constraint estimates.</p> <p>Results</p> <p>We propose a conservation signal that is produced by local Maximum Likelihood estimation of evolutionary parameters using an optimized sliding window and present a Kullback-Leibler projection that allows multiple different estimated parameters to be transformed into a conservation measure. This conservation measure does not rely on assumptions about neutral evolutionary substitution rates and little a priori assumptions on the properties of the conserved regions are imposed. We show the accuracy of our approach (KuLCons) on synthetic data and compare it to the scores generated by state-of-the-art methods (phastCons, GERP, SCONE) in an ENCODE region. We find that KuLCons is most often in agreement with the conservation/constraint signatures detected by GERP and SCONE while qualitatively very different patterns from phastCons are observed. Opposed to standard methods KuLCons can be extended to more complex evolutionary models, e.g. taking insertion and deletion events into account and corresponding results show that scores obtained under this model can diverge significantly from scores using the simpler model.</p> <p>Conclusion</p> <p>Our results suggest that discriminating among the different degrees of conservation is possible without making assumptions about neutral rates. We find, however, that it cannot be expected to discover considerably different constraint regions than GERP and SCONE. Consequently, we conclude that the reported discrepancies between experimentally verified functional and computationally identified constraint elements are likely not to be explained by biased neutral rate estimates.</p
Neurotoxicity with high dose disulfiram and vorinostat used for HIV latency reversal
OBJECTIVE: To examine whether administering both vorinostat and disulfiram to people with HIV (PWH) on antiretroviral therapy (ART) is safe and can enhance HIV latency reversal. DESIGN: Vorinostat and disulfiram, can increase HIV transcription in people with HIV (PWH) on antiretroviral therapy (ART). Together these agents may lead to significant HIV latency reversal. METHODS: Virologically suppressed PWH on ART received disulfiram 2000 mg daily for 28 days and vorinostat 400 mg daily on days 8-10 and 22-24. The primary endpoint was plasma HIV RNA on day 11 relative to baseline using a single copy assay. Assessments included cell-associated (CA) unspliced (US) RNA as a marker of latency reversal, HIV DNA in CD4+ T-cells, plasma HIV RNA and plasma concentrations of ART, vorinostat and disulfiram. RESULTS: The first two participants (P1 and P2) experienced grade 3 neurotoxicity leading to trial suspension. After 24 days, P1 presented with confusion, lethargy, and ataxia having stopped disulfiram and ART. Symptoms resolved by day 29. After 11 days, P2 presented with paranoia, emotional lability, lethargy, ataxia and study drugs were ceased. Symptoms resolved by day 23. CA-US RNA increased by 1.4- and 1.3-fold for P1 and P2 respectively. Plasma HIV RNA was detectable from day 8-37 (peak 81 copies/mL) for P2 but was not increased in P1 Antiretroviral levels were therapeutic and neuronal injury markers were elevated in P1. CONCLUSIONS: The combination of prolonged high dose disulfiram and vorinostat was not safe in PWH on ART and should not be pursued despite evidence of latency reversal
IOTA: recent science and technology
We present a brief review of recent scientific and technical advances at the Infrared Optical Telescope Array (IOTA). IOTA is a long-baseline interferometer located atop Mount Hopkins, Arizona. Recent work has emphasized the use of the three-telescope interferometer completed in 2002. We report on results obtained on a range of scientific targets, including AGB stars, Herbig AeBe Stars, binary stars, and the recent outburst of the recurrent nova RS Oph. We report the completion of a new spectrometer which allows visibility measurements at several high spectral resolution channels simultaneously. Finally, it is our sad duty to report that IOTA will be closed this year
Neuroscience and education: prime time to build the bridge
As neuroscience gains social traction and entices media attention, the notion that education has much to benefit from brain
research becomes increasingly popular. However, it has been argued that the fundamental bridge toward education is cognitive
psychology, not neuroscience. We discuss four specific cases in which neuroscience synergizes with other disciplines to serve
education, ranging from very general physiological aspects of human learning such as nutrition, exercise and sleep, to brain
architectures that shape the way we acquire language and reading, and neuroscience tools that increasingly allow the early
detection of cognitive deficits, especially in preverbal infants. Neuroscience methods, tools and theoretical frameworks have
broadened our understanding of the mind in a way that is highly relevant to educational practice. Although the bridge’s cement is
still fresh, we argue why it is prime time to march over it
Daily rhythms of the sleep-wake cycle
The amount and timing of sleep and sleep architecture (sleep stages) are determined by several factors, important among which are the environment, circadian rhythms and time awake. Separating the roles played by these factors requires specific protocols, including the constant routine and altered sleep-wake schedules. Results from such protocols have led to the discovery of the factors that determine the amounts and distribution of slow wave and rapid eye movement sleep as well as to the development of models to determine the amount and timing of sleep. One successful model postulates two processes. The first is process S, which is due to sleep pressure (and increases with time awake) and is attributed to a 'sleep homeostat'. Process S reverses during slow wave sleep (when it is called process S'). The second is process C, which shows a daily rhythm that is parallel to the rhythm of core temperature. Processes S and C combine approximately additively to determine the times of sleep onset and waking. The model has proved useful in describing normal sleep in adults. Current work aims to identify the detailed nature of processes S and C. The model can also be applied to circumstances when the sleep-wake cycle is different from the norm in some way. These circumstances include: those who are poor sleepers or short sleepers; the role an individual's chronotype (a measure of how the timing of the individual's preferred sleep-wake cycle compares with the average for a population); and changes in the sleep-wake cycle with age, particularly in adolescence and aging, since individuals tend to prefer to go to sleep later during adolescence and earlier in old age. In all circumstances, the evidence that sleep times and architecture are altered and the possible causes of these changes (including altered S, S' and C processes) are examined
'I'm not going to tell you cos you need to think about this': A conversation analysis study of managing advice resistance and supporting autonomy in undergraduate supervision
This is an accepted manuscript of an article published by Springer in Postdigital Science and Education, available online at: https://doi.org/10.1007/s42438-020-00194-5
The accepted version of the publication may differ from the final published version.This article firstly, critically analyses a face-to-face supervision meeting between an
undergraduate and a supervisor, exploring how the supervisor handles the twin strategies of
fostering autonomy while managing resistance to advice. Conversation Analysis is used as
both a theory and a method, with a focus on the use of accounts to support or resist advice.
The main contribution is the demonstration of how both the supervisor and student are jointly
responsible for the negotiation of advice, which is recycled and calibrated in response to the
student’s resistance. The supervisor defuses complaints by normalising them, and moving his
student on to practical solutions, often with humour. He lists his student’s achievements as
the foundation on which she can assert agency and build the actions he recommends.
Supervisor-student relationships are investigated through the lens of the affective dimensions
of learning, to explore how caring or empathy may serve to reduce resistance and make
advice more palatable. By juxtaposing physically present supervision with digitally-mediated
encounters, while acknowledging their mutual entanglement, the postdigital debate is
furthered. In the context of Covid-19, and rapid decisions by universities to bring in digital
platforms to capture student-teacher interactions, the analysis presented is in itself an act of
resistance against the technical control systems of the academy and algorithmic capitalism
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