Search results for " sensing"

Mediterranean Maritime Pollution: The Role Of Remote Sensing To Monitor And Mitigate

2010

Challenges in the use of Near Infrared Spectroscopy for improving wood quality: A review

2018

Aims of study: Forestry-related companies require quality monitoring methods capable to pass a large number of samples. This review paper is dealing with the utilization of near infrared (NIR) technique for wood analysis.Area of study: We have a global point of view for NIR applications and characterization of different kind of wood species is considered.Material and methods: NIR spectroscopy is a fast, non-destructive technique, applicable to any biological material, demanding little or no sample preparation. NIR spectroscopy and multivariate analysis serve well in laboratories where the conditions are controlled. The main challenges to NIR spectroscopy technique in field conditions are mo…

Molecular genetics of Staphylococcus epidermidis biofilms on indwelling medical devices.

2005

Staphylococcus epidermidis is an opportunistic pathogen associated with foreign body infections and nosocomial sepsis. The pathogenicity of S. epidermidis is mostly due to its ability to colonize indwelling polymeric devices and form a thick, multilayered biofilm. Biofilm formation is a major problem in treating S. epidermidis infection as biofilms provide significant resistance to antibiotics and to components of the innate host defenses. Various cell surface associated bacterial factors play a role in adherence and accumulation of the biofilm such as the polysaccharide intercellular adhesin and the autolysin AtlE. Furthermore, recent studies have shown that global regulators such as the …

Chemosensory signalling pathways involved in sensing of amino acids by the ghrelin cell

2015

AbstractTaste receptors on enteroendocrine cells sense nutrients and transmit signals that control gut hormone release. This study aimed to investigate the amino acid (AA) sensing mechanisms of the ghrelin cell in a gastric ghrelinoma cell line, tissue segments and mice. Peptone and specific classes of amino acids stimulate ghrelin secretion in the ghrelinoma cell line. Sensing of L-Phe occurs via the CaSR, monosodium glutamate via the TAS1R1-TAS1R3 while L-Ala and peptone act via 2 different amino acid taste receptors: CaSR & TAS1R1-TAS1R3 and CaSR & GPRC6A, respectively. The stimulatory effect of peptone on ghrelin release was mimicked ex vivo in gastric but not in jejunal tissue …

Snapshot Spectral Imaging

2018

This chapter describes an application of the spline-based wavelet frames to the spectral imaging. It presents a method that enables to convert a regular digital camera into a snapshot spectral imager by equipping the camera with a dispersive diffuser and with a compressed sensing-based algorithm for digital processing. The method relies on the assumption that typical images can be sparsely represented in the frame domain. The solution is found from the constrained \(l_{1}\) minimization of a functional by Bregman iterations. Results of optical experiments are reported. The chapter is based on the paper (Golub et al., Appl. Opt. 55, 432–443, (2016), [11]).

Localization of Multi-Class On-Road and Aerial Targets Using mmWave FMCW Radar

2021

mmWave radars play a vital role in autonomous systems, such as unmanned aerial vehicles (UAVs), unmanned surface vehicles (USVs), ground station control and monitoring systems. The challenging task when using mmWave radars is to estimate the accurate angle of arrival (AoA) of the targets, due to the limited number of receivers. In this paper, we present a novel AoA estimation technique, using mmWave FMCW radars operating in the frequency range 77–81 GHz by utilizing the mechanical rotation. Rotating the radar also increases the field of view in both azimuth and elevation. The proposed method estimates the AoA of the targets, using only a single transmitter and receiver. The measurements are…

Periodically nanostructured hydrogels for ethanol vapors sensing

2013

Chemical sensing using optics has been under extensive research all over the world during last decades and many optical chemical sensors are nowadays finding increasing applications in industry, environmental monitoring, medicine, biomedicine and chemical analysis. These optical sensors can be based on various optical principles, such as absorbance, reflectance or transmittance, luminescence and fluorescence, covering different regions of the spectrum (UV, visible, IR, NIR). Optical chemical sensors have several advantages over conventional electricity-based sensors, in terms of selectivity, immunity to electromagnetic interference, higher sensitivity, and they are also relatively inexpensi…

Nanowire ordered Arrays for electrochemical sensing of H2O2

2016

In this work, we present the performance of nanostructured array of Cu for electrochemical sensors of hydrogen peroxide. Nanostructured sensors are obtained by template synthesis in commercial polycarbonate membranes. Arrays of Cu nanowires were fabricated through a displacement deposition reaction that permits to obtain nanostructures directly and without the use of an external power supply. To test the performance of nanostructured sensors, electrochemical experiments were carried out in an aqueous solution with different amounts of hydrogen peroxide. In order to obtain sensors with stable performance, we found that it is essential to increase wettability of the nanostructures through add…

Noise Reduction and Gap Filling of fAPAR Time Series Using an Adapted Local Regression Filter

2014

Time series of remotely sensed data are an important source of information for understanding land cover dynamics. In particular, the fraction of absorbed photosynthetic active radiation (fAPAR) is a key variable in the assessment of vegetation primary production over time. However, the fAPAR series derived from polar orbit satellites are not continuous and consistent in space and time. Filtering methods are thus required to fill in gaps and produce high-quality time series. This study proposes an adapted (iteratively reweighted) local regression filter (LOESS) and performs a benchmarking intercomparison with four popular and generally applicable smoothing methods: Double Logistic (DLOG), sm…

Joint local quantization and linear cooperation in spectrum sensing for cognitive radio networks

2014

—In designing cognitive radio networks (CRNs), protecting the license holders from harmful interference while maintaining acceptable quality-of-service (QoS) levels for the secondary users is a challenge effectively mitigated by cooperative spectrum sensing schemes. In this paper, cooperative spectrum sensing in CRNs is studied as a three-phase process composed of local sensing, reporting, and decision/data fusion. Then, a significant tradeoff in designing the reporting phase, i.e., the effect of the number of bits used in local sensing quantization on the overall sensing performance is identified and formulated. In addition, a novel approach is proposed to jointly optimize the linear soft-…