Search results for "Alarm"
showing 10 items of 80 documents
Power allocation optimization in OFDM-based cognitive radios based on sensing information
2011
Owing to the non-zero probability of the missed detection and false alarm of active primary transmission, a certain degree of performance degradation of the primary user (PU) from cognitive radio users (CRs) is unavoidable. In this paper, we consider OFDM-based communication systems and present efficient algorithms to maximize the total rate of the CR by optimizing jointly both the detection operation and the power allocation, taking into account the influence of the probabilities of missed detection and false alarm, namely, the sensing accuracy. The optimization problem can be formulated as a two-variable non-convex problem, which can be solved approximately by using an alternating directi…
Age-dependent responses to alarm calls depend on foraging activity in Willow TitsPoecile montanus
2011
Survivorship in animals depends on both foraging activities and avoidance of predation, and thus behavioural decisions often reflect a trade-off between predation risk and foraging efficiency. In this experimental study, we compared behavioural responses of free-living adult and juvenile Willow Tits Poecile montanus to a conspecific alarm call in two treatments. The alarm call was played back when a focal bird was either not feeding, or feeding on a sunflower seed on the middle part of a spruce branch. When feeding at the time of the alarm call, juveniles more often stayed motionless or moved shorter distances than adults. Our results suggest that in hierarchical groups, juveniles are force…
Algunas reflexiones sobre la percepción del cambio climático en una muestra de población adulta de nivel cultural medio
1994
El cambio climático es uno de los aspectos del Medio Ambiente que mayor eco social ha alcanzado en los últimos años. El tema ha trascendido de los centros de investigación a la opinión pública de manera distorsionada, debido, en gran parte, a medios de comunicación poco rigurosos. Este trabajo reflexiona sobre la percepción del fenómeno por parte de una muestra de población adulta de nivel cultural medio, que da por sentado un cambio climático importante, producido en los últimos años por el hombre y que ha originado la mayor parte de catástrofes naturales de tipo hidrometeorológico. Esta imagen catastrofista contrasta con la indeterminación que muestra la comunidad científica, que pone de …
Behaviour and neural responses in crucian carp to skin odours from cross-order species
2012
Many teleost species respond with fright reactions to olfactory cues from injured skin of conspecifics, but they may also display responses to skin extracts of heterospecific fish. In the present study, we exposed crucian carp to skin extracts of conspecifics and three cross-order species of fish (brown trout, pike, and perch). Behavioural experiments showed that conspecific skin extracts induced fright reactions in crucian carp; extracts of brown trout induced such behaviour less frequently, while extracts of perch and pike were poor inducers of fright responses. The olfactory bulb is chemo-topically organized, and different sub-sets of neurons respond to functionally related odorants that…
Deep learning for core-collapse supernova detection
2021
The detection of gravitational waves from core-collapse supernova (CCSN) explosions is a challenging task, yet to be achieved, in which it is key the connection between multiple messengers, including neutrinos and electromagnetic signals. In this work, we present a method for detecting these kind of signals based on machine learning techniques. We tested its robustness by injecting signals in the real noise data taken by the Advanced LIGO-Virgo network during the second observing run, O2. We trained a newly developed Mini-Inception Resnet neural network using time-frequency images corresponding to injections of simulated phenomenological signals, which mimic the waveforms obtained in 3D num…
Implementation of a two stage fully-blind self-adapted spectrum sensing algorithm
2017
In this paper, an experimental validation of a combined two-stage detector called 2EMC is carried out. The detector is proposed in [1]. The 2EMC is composed of energy detector as a primary stage and maximum-minimum eigenvalue detector as a secondary stage. The 2EMC outperforms the two individual detectors in terms of the probability of detection for the same probability of false alarm. Regarding the complexity measured in the sensing time, the 2EMC sensing time is bounded by the sensing times of the two individual detectors. 2EMC incorporates noise estimation that is used by the energy detector, which makes it fully-blind and self-adapted detector. The noise estimator performance is express…
Cellular Models and Assays to Study NLRP3 Inflammasome Biology
2020
The NLRP3 inflammasome is a multi-protein complex that initiates innate immunity responses when exposed to a wide range of stimuli, including pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs). Inflammasome activation leads to the release of the pro-inflammatory cytokines interleukin (IL)-1β and IL-18 and to pyroptotic cell death. Over-activation of NLRP3 inflammasome has been associated with several chronic inflammatory diseases. A deep knowledge of NLRP3 inflammasome biology is required to better exploit its potential as therapeutic target and for the development of new selective drugs. To this purpose, in the past few years, several tools have…
Ventilator Settings to Avoid Nuisance Alarms During Mouthpiece Ventilation
2016
BACKGROUND: A recent study found that activation of disconnection and low-pressure alarms is common during mouthpiece ventilation and may represent a major limitation to its use. The aim of this bench study was: (1) to investigate the technical aspects that can influence the setting of the ventilator during mouthpiece ventilation and (2) to provide a practical setting strategy to avoid the alarm activation. METHODS: Eight life-support ventilators able to deliver volume controlled ventilation were tested in a bench study using a single-limb non-vented circuit configuration connected to a standard mouthpiece. Disconnection and apnea alarm were turned off or set at the least sensitive setting.…
Detection and Recognition of Target Signals in Radar Clutter via Adaptive CFAR Tests
2006
In this paper, adaptive CFAR tests are described which allow one to classify radar clutter into one of several major categories, including bird, weather, and target classes. These tests do not require the arbitrary selection of priors as in the Bayesian classifier. The decision rule of the recognition techniques is in the form of associating the p-dimensional vector of observations on the object with one of the m specific classes. When there is the possibility that the object does not belong to any of the m classes, then this object is to be classified as belonging to one of the m classes or to class m+1 whose distribution is unspecified. The tests are invariant to intensity changes in the …