Search results for " Senso"
showing 10 items of 1766 documents
Quantitative ultrasound predicts bone mineral density and failure load in human lumbar vertebrae
2006
Quantitative ultrasound is in widespread clinical use for assessment of bone quality at peripheral skeletal sites, but has not yet been applied to those sites in the axial skeleton, such as the spine and hip, where osteoporotic fractures are common.Ultrasound measurements were made in 11 cadaveric vertebrae and relationships with bone mineral density and failure load were investigated. An ultrasonic imaging system was used to measure speed of sound, broadband ultrasonic attenuation, and attenuation at a single frequency, through the vertebral body in the sagittal plane. Ultrasonic measurements were averaged over a region of interest centrally within the vertebral body, and were calculated w…
A Rapid and Sensitive Strip-Based Quick Test for Nerve Agents Tabun, Sarin, and Soman Using BODIPY-Modified Silica Materials
2016
Test strips that in combination with a portable fluorescence reader or digital camera can rapidly and selectively detect chemical warfare agents (CWAs) such as Tabun (GA), Sarin (GB), and Soman (GD) and their simulants in the gas phase have been developed. The strips contain spots of a hybrid indicator material consisting of a fluorescent BODIPY indicator covalently anchored into the channels of mesoporous SBA silica microparticles. The fluorescence quenching response allows the sensitive detection of CWAs in the mu g m(-3) range in a few seconds.
Sudden sensorineural hearing loss as prodromal symptom of anterior inferior cerebellar artery infarction.
2011
Sudden sensorineural hearing loss is a clinical condition characterized by a sudden onset of unilateral or bilateral hearing loss. In recent years sudden deafness has been frequently described in association with anterior inferior cerebellar artery (AICA) infarction generally presenting along with other brainstem and cerebellar signs such as ataxia, dysmetria and peripheral facial palsy. The authors report a rare clinical case of a 53-year-old man who suddenly developed hearing loss and tinnitus without any brainstem or cerebellar signs. Computed tomography of his brain was normal, and the audiological results localized the lesion causing deafness to the inner ear. Surprisingly, magnetic re…
Robust current observer design for DC-DC converters
2014
In recent years several fast response controllers have been proposed for DC-DC converters. The majority of them rely on a cascade control structure involving the inductor's current in the control function as its faster dynamics, respect to output voltage, allows a significant increase in the regulation performance; the drawback is the need of a proper and expensive current sensor. In this paper a simple and robust formulation for the design of a current observer, based on the output voltage measurement is presented. The formulation is common for the three standard DC-DC converters and the resulting observer is robust to load variation. The observers have been tested in a cascade PI control …
Orientational glass behaviour of K Br0.96(CN)0.04
1981
Ultrasonic measurements on the mixed crystal K Br0.96(CN)0.04 show a minimum of most of the elastic constants at 16 K. In addition we determinedc11(T) at 10 MHz and at 50 MHz observing dispersion effects. These results and previous Brillouin and neutron scattering results of other authors on higher CN-concentrations are interpreted by an orientational glass behaviour. A semiquantitative description is given in terms of the mean random field approximation.
Detecting faulty wireless sensor nodes through Stochastic classification
2011
In many distributed systems, the possibility to adapt the behavior of the involved resources in response to unforeseen failures is an important requirement in order to significantly reduce the costs of management. Autonomous detection of faulty entities, however, is often a challenging task, especially when no direct human intervention is possible, as is the case for many scenarios involving Wireless Sensor Networks (WSNs), which usually operate in inaccessible and hostile environments. This paper presents an unsupervised approach for identifying faulty sensor nodes within a WSN. The proposed algorithm uses a probabilistic approach based on Markov Random Fields, requiring exclusively an ana…
Index-based triangulation method for efficient generation of large three-dimensional ultrasonic C-scans
2018
The demand for high-speed ultrasonic scanning of large and complex components is driven by a desire to reduce production bottlenecks during the non-destructive evaluation (NDE) of critical parts. Emerging systems (including robotic inspection) allow for the collection of large volumes of data in short time spans, compared to existing inspection systems. To maximise throughput, it is crucial that the reconstructed inspection datasets are generated and evaluated rapidly without loss of detail. This requires new data visualisation and analysis tools capable of mapping complex geometries while guaranteeing full coverage. This paper presents an entirely new approach for the visualisation of thre…
Data Compression Approach for Long-Term Monitoring of Pavement Structures
2019
Pavement structures are designed to withstand continuous damage during their design life. Damage starts as soon as the pavement is open to traffic and increases with time. If maintenance activities are not considered in the initial design or considered but not applied during the service life, damage will grow to a point where rehabilitation may be the only and most expensive option left. In order to monitor the evolution of damage and its severity in pavement structures, a novel data compression approach based on cumulative measurements from a piezoelectric sensor is presented in this paper. Specifically, the piezoelectric sensor uses a thin film of polyvinylidene fluoride to sense the ener…
3D Integration : towards high-performance innovative imaging sensors
2017
Nowadays, CMOS image sensors are almost exclusively architectured around analog pixels. A transition to purely digital pixels would significantly improve the performances of imagers. Unfortunately, such an approach is difficult to consider because it causes an oversized and unusable pixel for the consumer market. One of the promising ways to solve this problem of pixel integration is to think not only in 2D dimensions, but in 3D dimensions by distributing the different functionalities on several interconnected wafers.Thus, the work presented in this manuscript describes the design of a purely digital image sensor in CMOS 3D-IC 130 nm Tezzaron technology. This sensor is architectured around …
A low power interface circuit design for a CMOS based smart optical sensor
2012
In this paper, a CMOS interface circuit as part of an optical sensor-based microsystem for pH monitoring applications is presented. The proposed circuit is capable of processing a voltage signal produced by the light transducer and generating 8-bit digital outputs representing the color information (i.e. wavelength). A resolution of 8 different colors has been achieved as a proof of concept and can easily be extended to a higher number of colors without a major modification in the architecture. The proposed interface circuit is a mixed-signal solution that consists of analog as well as digital building blocks along with a light transducer. It can be used as a portable and non-intrusive opti…