67 research outputs found
FPGA Implementation of Gaussian Mixture Model Algorithm for 47 fps Segmentation of 1080p Video
Circuits and systems able to process high quality video in real time are fundamental in nowadays imaging systems. The circuit proposed in the paper, aimed at the robust identification of the background in video streams, implements the improved formulation of the Gaussian Mixture Model (GMM) algorithm that is included in the OpenCV library. An innovative, hardware oriented, formulation of the GMM equations, the use of truncated binary multipliers, and ROM compression techniques allow reduced hardware complexity and increased processing capability. The proposed circuit has been designed having commercial FPGA devices as target and provides speed and logic resources occupation that overcome previously proposed implementations. The circuit, when implemented on Virtex6 or StratixIV, processes more than 45 frame per second in 1080p format and uses few percent of FPGA logic resources
Pyrosequencing analysis of fungal assemblages from geographically distant, disparate soils reveals spatial patterning and a core mycobiome
Identifying a soil core microbiome is crucial to appreciate the established microbial consortium, which is not usually subjected to change and, hence, possibly resistant/resilient to disturbances and a varying soil context. Fungi are a major part of soil biodiversity, yet the mechanisms driving their large-scale ecological ranges and distribution are poorly understood. The degree of fungal community overlap among 16 soil samples from distinct ecosystems and distant geographic localities (truffle grounds, a Mediterranean agro-silvo-pastoral system, serpentine substrates and a contaminated industrial area) was assessed by examining the distribution of fungal ITS1 and ITS2 sequences in a dataset of 454 libraries. ITS1 and ITS2 sequences were assigned to 1,660 and 1,393 Operational Taxonomic Units (OTUs; as defined by 97% sequence similarity), respectively. Fungal beta-diversity was found to be spatially autocorrelated. At the level of individual OTUs, eight ITS1 and seven ITS2 OTUs were found in all soil sample groups. These ubiquitous taxa comprised generalist fungi with oligotrophic and chitinolytic abilities, suggesting that a stable core of fungi across the complex soil fungal assemblages is either endowed with the capacity of sustained development in the nutrient-poor soil conditions or with the ability to exploit organic resources (such as chitin) universally distributed in soils
The plants, rituals and spells that 'cured' helminthiasis in Sicily
<p>Abstract</p> <p>Background</p> <p>The author reports on the plants, rituals and spells used against worms and the so-called <it>scantu </it>(fright) in some areas of Sicily. The work is based on ethnobotanical research carried out, prevalently, between 2002-2006, in some areas of Eastern, South-Eastern, North-Central and South-Central Sicily.</p> <p>Methods</p> <p>This research is based on dialogue. Senior 'healers' were contacted; furthermore, doctors, teachers, farmers and in general 'experts' with herbs and 'magic' rituals. Information was collected about the way the plants of folk medicine are prepared. The interviewees were also invited to recite prayers and spells against helminthiasis.</p> <p>Results</p> <p>The author has highlighted the importance of how, in some parts of Sicily, some ailments like helminthiasis and other correlated pathologies like <it>scantu </it>are 'treated' and, especially within the rural social classes, by folk medicine remedies, herbal practises, particular prayers, rituals and spells.</p> <p>Conclusion</p> <p>As regards health/illness, it should be noted that in the last ten years conventional medicine has provided very satisfactory results even resolving potentially mortal pathologies. However, in certain social classes, there is no real collaboration between conventional and folk medicine; so for some senior citizens, the 'healer' with his rituals and empirical and magical herbs is still the person to turn to for the 'cure' of particular ailments. Interest in these practises from ancestral heritage in an advanced country like Italy, is only relevant if the aim is to recoup a cultural identity which is already in decline.</p> <p>It is significant to report a piece: on 14 October 2007 the news on a well-known national Italian TV channel reported an interview with a 94 year-old man from Arbatax (Sardinia) referred to as a 'healer' because both his townspeople and others from all over the world go to him for his cures. He is not paid except in kind and has been known to cure St. Anthony's fire, burns, scalding and marine fungal infections, by smearing his saliva over the infected part and reciting 'special words'.</p
Dark sectors 2016 Workshop: community report
This report, based on the Dark Sectors workshop at SLAC in April 2016,
summarizes the scientific importance of searches for dark sector dark matter
and forces at masses beneath the weak-scale, the status of this broad
international field, the important milestones motivating future exploration,
and promising experimental opportunities to reach these milestones over the
next 5-10 years
US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report
This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in
Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference
Disease-Modifying Therapies and Coronavirus Disease 2019 Severity in Multiple Sclerosis
Objective: This study was undertaken to assess the impact of immunosuppressive and immunomodulatory therapies on the severity of coronavirus disease 2019 (COVID-19) in people with multiple sclerosis (PwMS).
Methods: We retrospectively collected data of PwMS with suspected or confirmed COVID-19. All the patients had complete follow-up to death or recovery. Severe COVID-19 was defined by a 3-level variable: mild disease not requiring hospitalization versus pneumonia or hospitalization versus intensive care unit (ICU) admission or death. We evaluated baseline characteristics and MS therapies associated with severe COVID-19 by multivariate and propensity score (PS)-weighted ordinal logistic models. Sensitivity analyses were run to confirm the results.
Results: Of 844 PwMS with suspected (n = 565) or confirmed (n = 279) COVID-19, 13 (1.54%) died; 11 of them were in a progressive MS phase, and 8 were without any therapy. Thirty-eight (4.5%) were admitted to an ICU; 99 (11.7%) had radiologically documented pneumonia; 96 (11.4%) were hospitalized. After adjusting for region, age, sex, progressive MS course, Expanded Disability Status Scale, disease duration, body mass index, comorbidities, and recent methylprednisolone use, therapy with an anti-CD20 agent (ocrelizumab or rituximab) was significantly associated (odds ratio [OR] = 2.37, 95% confidence interval [CI] = 1.18-4.74, p = 0.015) with increased risk of severe COVID-19. Recent use (<1 month) of methylprednisolone was also associated with a worse outcome (OR = 5.24, 95% CI = 2.20-12.53, p = 0.001). Results were confirmed by the PS-weighted analysis and by all the sensitivity analyses.
Interpretation: This study showed an acceptable level of safety of therapies with a broad array of mechanisms of action. However, some specific elements of risk emerged. These will need to be considered while the COVID-19 pandemic persists
Direct Digital Frequency Synthesizers implemented on high end FPGA devices
Direct Digital Frequency Synthesizer (DDFS) circuits
are routinely implemented in many electronic systems.
Advanced DDFS design techniques have been proposed and
optimized for ASIC (Application Specific Integrated Circuits)
implementations. Nowadays, FPGA devices are frequently chosen
as target for digital circuits. This paper presents the FPGA
implementation of state of the art DDFS architectures and
compares their performance providing hints on optimal design
as a function of the chosen performance parameter
FPGA-based architecture for real time segmentation and denoising of HD video
The identification of moving objects is a basic
step in computer vision. The identification begins with the
segmentation and is followed by a denoising phase. This
paper proposes the FPGA hardware implementation of
segmentation and denoising unit. The segmentation is
conducted using the Gaussian mixture model (GMM), a
probabilistic method for the segmentation of the background.
The denoising is conducted implementing the
morphological operators of erosion, dilation, opening and
closing. The proposed circuit is optimized to perform real
time processing of HD video sequences (1,920 9 1,080 @
20 fps) when implemented on FPGA devices. The circuit
uses an optimized fixed width representation of the data
and implements high performance arithmetic circuits. The
circuit is implemented on Xilinx and Altera FPGA.
Implemented on xc5vlx50 Virtex5 FPGA, it can process
24 fps of an HD video using 1,179 Slice LUTs and 291
Slice Registers; the dynamic power dissipation is
0.46 mW/MHz. Implemented on EP2S15F484C3 StratixII,
it provides a maximum working frequency of 44.03 MHz
employing 5038 Logic Elements and 7,957 flip flop with a
dynamic power dissipation of 4.03 mW/MHz
ASIC and FPGA implementation of the Gaussian Mixture Model algorithm for real-time segmentation of High Definition video
Background identification is a common feature in
many video processing systems. The paper proposes two hardware
implementations of the OpenCV version of the Gaussian
Mixture Model (GMM), a background identification algorithm.
The implemented version of the algorithm allows a fast initialization
of the background model while an innovative, hardware
oriented, formulation of the GMM equations makes the proposed
circuits able to perform real time background identification on
High Definition (HD) video sequences with frame size 19201080.
The first of the two circuits has been designed having commercial
FPGA devices as target. When implemented on Virtex6
vlx75t, the proposed circuit processes 91 HD fps and uses 3% of
FPGA logic resources.
The second circuit has been oriented to the implementation in
UMC-90nm CMOS standard cell technology and is proposed in
two versions. Both versions can process at a frame rate higher
than 60 HD fps. The first version uses the constant voltage scaling
technique to provide a low power implementation. It provides
silicon area occupation of 28847 m2 and energy dissipation per
pixel of 15.3 pJ/pixel. The second version is designed to reduce
silicon area utilization and occupies 21847 m2 with an energy
dissipation of 49.4 pJ/pixel
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