111 research outputs found
Spin-Based Neuron Model with Domain Wall Magnets as Synapse
We present artificial neural network design using spin devices that achieves
ultra low voltage operation, low power consumption, high speed, and high
integration density. We employ spin torque switched nano-magnets for modelling
neuron and domain wall magnets for compact, programmable synapses. The spin
based neuron-synapse units operate locally at ultra low supply voltage of 30mV
resulting in low computation power. CMOS based inter-neuron communication is
employed to realize network-level functionality. We corroborate circuit
operation with physics based models developed for the spin devices. Simulation
results for character recognition as a benchmark application shows 95% lower
power consumption as compared to 45nm CMOS design
Cycling as a smart and green mode of transport in small touristic cities
Cycling as a mode of transport is a low-cost, health-improving way to travel and offers environmental benefits for the cities that promote it. It is only recently, though, with concerns over climate change, pollution, congestion, and obesity among others, that have cities throughout the world have begun to implement policies to promote cycling. In Greece, however, the use of the bicycle is limited. In Preveza, a small touristic city in Northwestern Greece where the use of the bicycle is prominent when compared to other Greek cities, there are efforts to promote cycling. Through the aid of a structured questionnaire, the residents evaluated the suitability of the city for cycling, the existing infrastructure, appropriate education, and behavior of cyclists and drivers. More than half of the residents use bicycles as their transportation and stated that bicycles are an inexpensive way of transport in the city and had the opinion that the state should encourage bicycle use by supporting subvention in bicycle acquisition. Two-thirds of the residents evaluated the cycling facilities of their city as adequate, but unsafe for young cyclists who do not follow the rules of transport. Adult cyclists, in contrast, were more loyal to the code, but stated that drivers did not respect their presence on the roads. This research provides important information on the perceived shortcomings of cycling as a transport mode in Preveza that may be of interest to towns/cities with similar characteristics.FCT-Foundation for Science and Technology [UID/SOC/04020/2013]info:eu-repo/semantics/publishedVersio
Ultra Low Energy Analog Image Processing Using Spin Neurons
In this work we present an ultra low energy, 'on-sensor' image processing
architecture, based on cellular array of spin based neurons. The 'neuron'
constitutes of a lateral spin valve (LSV) with multiple input magnets,
connected to an output magnet, using metal channels. The low resistance,
magneto-metallic neurons operate at a small terminal voltage of ~20mV, while
performing analog computation upon photo sensor inputs. The static current-flow
across the device terminals is limited to small periods, corresponding to
magnet switching time, and, is determined by a low duty-cycle system-clock.
Thus, the energy-cost of analog-mode processing, inevitable in most image
sensing applications, is reduced and made comparable to that of dynamic and
leakage power consumption in peripheral CMOS units. Performance of the proposed
architecture for some common image sensing and processing applications like,
feature extraction, halftone compression and digitization, have been obtained
through physics based device simulation framework, coupled with SPICE. Results
indicate that the proposed design scheme can achieve more than two orders of
magnitude reduction in computation energy, as compared to the state of art CMOS
designs, that are based on conventional mixed-signal image acquisition and
processing schemes. To the best of authors' knowledge, this is the first work
where application of nano magnets (in LSV's) in analog signal processing has
been proposed
Haemoperitoneum Due to Spontaneous Rupture of a Liver Metastasis
Spontaneous rupture of a liver metastasis is a life-threatening complication of metastatic liver disease. Although metastatic liver lesions
are much more common than primary tumours, spontaneous rupture of a liver metastasis is rare. Therapeutic decisions must take into
account the extent of metastatic liver disease and the patient’s performance status. Transarterial embolization may be considered in cases
of ongoing haemorrhage despite initial conservative measures. We describe a case of haemoperitoneum due to spontaneous rupture of a
liver metastasis in a 72-year-old patient with carcinoma of unknown origin who responded well to conservative management
Thyroid abscess as a complication of percutaneous ethanol ablation of cystic thyroid nodules
Not required for Clinical Vignette
A novel use of the caesium-137 technique to estimate human interference and historical water level in a Mediterranean Temporary Pond
Δημοσίευση σε επιστημονικό περιοδικόSummarization: The sustainability of, and the effects of human pressures on, Omalos Mediterranean Temporary Pond (MTP), Chanea, Greece was assessed. The 137Cs technique was used to identify alleged anthropogenic interference (excavation) in the studied area. It was found that about one third of the ponds bed surface material had been removed and disposed of on the northeast edge, confirming unplanned excavations that took place in the MTP area some years ago. Nonetheless, five years after the excavation, the MTP's ecosystem (flora and fauna) had recovered, which indicates that these small ecosystems are resilient to direct human pressures, like excavations. Moreover, with the 137Cs technique it was possible to identify the historical water level of Omalos MTP, when the fallout from the Chernobyl accident reached this area, in May of 1986. Therefore, the 137Cs technique can be useful in the identification of the historical water level of small MTPs and other ephemeral water bodies. Applications include the verification and validation of hydrological models.Presented on: Journal of Environmental Radioactivit
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