On the Performance of Energy Criterion Method in Wi-Fi Transient Signal Detection

In the development of radiofrequency fingerprinting (RFF), one of the major challenges is to extract subtle and robust features from transmitted signals of wireless devices to be used in accurate identification of possible threats to the wireless network. To overcome this challenge, the use of the transient region of the transmitted signals could be one of the best options. For an efficient transient-based RFF, it is also necessary to accurately and precisely estimate the transient region of the signal. Here, the most important difficulty can be attributed to the detection of the transient starting point. Thus, several methods have been developed to detect transient start in the literature. Among them, the energy criterion method based on the instantaneous amplitude characteristics (EC-a) was shown to be superior in a recent study. The study reported the performance of the EC-a method for a set of Wi-Fi signals captured from a particular Wi-Fi device brand. However, since the transient pattern varies according to the type of wireless device, the device diversity needs to be increased to achieve more reliable results. Therefore, this study is aimed at assessing the efficiency of the EC-a method across a large set of Wi-Fi signals captured from various Wi-Fi devices for the first time. To this end, Wi-Fi signals are first captured from smartphones of five brands, for a wide range of signal-to-noise ratio (SNR) values defined as low (−3 to 5 dB), medium (5 to 15 dB), and high (15 to 30 dB). Then, the performance of the EC-a method and well-known methods was comparatively assessed, and the efficiency of the EC-a method was verified in terms of detection accuracy.

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Eddy Current Detecting of Leak Hole in Pipeline by Wavelet Packet Signal Analysis Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.291-294.2486 ◽

2013 ◽

Vol 291-294 ◽

pp. 2486-2491

Author(s):

Yue Shen ◽

Ling Tan Zhang

Keyword(s):

Eddy Current ◽

Steel Plate ◽

Multiple Scales ◽

Signal To Noise Ratio ◽

Wavelet Packet ◽

Measuring Method ◽

Transient Signal ◽

Measured Signal ◽

Accurate Identification ◽

Time Frequency

In the process of detecting leak hole in pipeline by intelligent pig with eddy current measuring method, the cut off effect of eddy current field in the closed cross section of leak hole in steel plate is weak due to geometric deformation of eddy current on the edge of the hole produced by destroyed drilling. As a result, the measured signal is very unobvious. Meanwhile, owing to the rough surface of steel plate, the periodic interference generated by movement of the detecting probe cannot be eliminated or be inhibited easily by conventional signal processing methods for its large amplitude and approximate frequency band with the leak hole signals, the signal to noise ratio (SNR) of measured signal is very low and the accurate identification of leak hole cannot be guaranteed. The wavelet transform, with characteristics of time-frequency localization and multiple scales, is a useful and effective method for identifying singularity of the signals and adapts to detect the transient signal or extract non-stationary information in the signals with strong periodic interference and noise. The reconstructing signal SNR will be increased greatly in eddy current detecting of leak hole in the pipeline with wavelet packet analysis of the signal by constructing the self-defined cost function based on maximum SNR to obtain optimal wavelet packet basis function. This ensures good detection and location of leak hole in the pipeline.

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Hearing Aid Self-Adjustment: Effects of Formal Speech-Perception Test and Noise

Trends in Hearing ◽

10.1177/2331216520930545 ◽

2020 ◽

Vol 24 ◽

pp. 233121652093054

Author(s):

Carol L. Mackersie ◽

Arthur Boothroyd ◽

Harinath Garudadri

Keyword(s):

Speech Perception ◽

Hearing Aids ◽

Signal To Noise Ratio ◽

Hearing Aid ◽

Sound Field ◽

Online Processing ◽

Starting Point ◽

Wide Range ◽

Monosyllabic Words ◽

Response Amplification

While listening to recorded sentences with a sound-field level of 65 dB SPL, 24 adults with hearing-aid experience used the “Goldilocks” explore-and-select procedure to adjust level and spectrum of amplified speech to preference. All participants started adjustment from the same generic response. Amplification was provided by a custom-built Master Hearing Aid with online processing of microphone input. Primary goals were to assess the effects of including a formal speech-perception test between repeated self-adjustments and of adding multitalker babble (signal-to-noise ratio +6 dB) during self-adjustment. The speech test did not affect group-mean self-adjusted output, which was close to the National Acoustics Laboratories’ prescription for Non-Linear hearing aids. Individuals, however, showed a wide range of deviations from this prescription. Extreme deviations at the first self-adjustment fell by a small but significant amount at the second. The multitalker babble had negligible effect on group-mean self-selected output but did have predictable effects on word recognition in sentences and on participants’ opinion regarding the most important subjective criterion guiding self-adjustment. Phoneme recognition in monosyllabic words was better with the generic starting response than without amplification and improved further after self-adjustment. The findings continue to support the efficacy of hearing aid self-fitting, at least for level and spectrum. They do not support the need for inclusion of a formal speech-perception test, but they do support the value of completing more than one self-adjustment. Group-mean data did not indicate a need for threshold-based prescription as a starting point for self-adjustment.

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Discovery of Antibacterial Agents Inhibiting the Energy-Coupling Factor (ECF) Transporters by Structure-Based Virtual Screening

10.26434/chemrxiv.11728710 ◽

2020 ◽

Author(s):

Eleonora Diamanti ◽

Inda Setyawati ◽

Spyridon Bousis ◽

leticia mojas ◽

lotteke Swier ◽

...

Keyword(s):

Virtual Screening ◽

Antibacterial Agents ◽

Antimicrobial Agents ◽

Energy Coupling ◽

Coupling Factor ◽

Design Synthesis ◽

Screening Design ◽

Starting Point ◽

Wide Range ◽

Vitamin Uptake

Here, we report on the virtual screening, design, synthesis and structure–activity relationships (SARs) of the first class of selective, antibacterial agents against the energy-coupling factor (ECF) transporters. The ECF transporters are a family of transmembrane proteins involved in the uptake of vitamins in a wide range of bacteria. Inhibition of the activity of these proteins could reduce the viability of pathogens that depend on vitamin uptake. Because of their central role in the metabolism of bacteria and their absence in humans, ECF transporters are novel potential antimicrobial targets to tackle infection. The hit compound’s metabolic and plasma stability, the potency (20, MIC Streptococcus pneumoniae = 2 µg/mL), the absence of cytotoxicity and a lack of resistance development under the conditions tested here suggest that this scaffold may represent a promising starting point for the development of novel antimicrobial agents with an unprecedented mechanism of action.<br>

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Detectivity optimization to detect of ultraweak light fluxes with an EM-CCD as binary photon counter array

Scientific Reports ◽

10.1038/s41598-021-82611-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ibtissame Khaoua ◽

Guillaume Graciani ◽

Andrey Kim ◽

François Amblard

Keyword(s):

Dynamic Range ◽

Signal To Noise Ratio ◽

Photon Counting ◽

Detection Methods ◽

Strong Nonlinearity ◽

Wide Range ◽

Depth Analysis ◽

Spatially Extended ◽

Extended Sources ◽

Photon Counting Mode

AbstractFor a wide range of purposes, one faces the challenge to detect light from extremely faint and spatially extended sources. In such cases, detector noises dominate over the photon noise of the source, and quantum detectors in photon counting mode are generally the best option. Here, we combine a statistical model with an in-depth analysis of detector noises and calibration experiments, and we show that visible light can be detected with an electron-multiplying charge-coupled devices (EM-CCD) with a signal-to-noise ratio (SNR) of 3 for fluxes less than $$30\,{\text{photon}}\,{\text{s}}^{ - 1} \,{\text{cm}}^{ - 2}$$ 30 photon s - 1 cm - 2 . For green photons, this corresponds to 12 aW $${\text{cm}}^{ - 2}$$ cm - 2 ≈ $$9{ } \times 10^{ - 11}$$ 9 × 10 - 11 lux, i.e. 15 orders of magnitude less than typical daylight. The strong nonlinearity of the SNR with the sampling time leads to a dynamic range of detection of 4 orders of magnitude. To detect possibly varying light fluxes, we operate in conditions of maximal detectivity $${\mathcal{D}}$$ D rather than maximal SNR. Given the quantum efficiency $$QE\left( \lambda \right)$$ Q E λ of the detector, we find $${ \mathcal{D}} = 0.015\,{\text{photon}}^{ - 1} \,{\text{s}}^{1/2} \,{\text{cm}}$$ D = 0.015 photon - 1 s 1 / 2 cm , and a non-negligible sensitivity to blackbody radiation for T > 50 °C. This work should help design highly sensitive luminescence detection methods and develop experiments to explore dynamic phenomena involving ultra-weak luminescence in biology, chemistry, and material sciences.

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Modal frequencies of bridges from GNSS (GPS) monitoring data: Experimental, statistical evidence

Bridge Structures ◽

10.3233/brs-210184 ◽

2021 ◽

Vol 17 (1-2) ◽

pp. 3-14

Author(s):

Stathis C. Stiros ◽

F. Moschas ◽

P. Triantafyllidis

Keyword(s):

Signal To Noise Ratio ◽

Vertical Axis ◽

Bridge Monitoring ◽

Low Snr ◽

True Value ◽

Gps Satellites ◽

Wide Range ◽

Spectral Peaks ◽

Monitoring Survey ◽

True Frequency

GNSS technology (known especially for GPS satellites) for measurement of deflections has proved very efficient and useful in bridge structural monitoring, even for short stiff bridges, especially after the advent of 100 Hz GNSS sensors. Mode computation from dynamic deflections has been proposed as one of the applications of this technology. Apart from formal modal analyses with GNSS input, and from spectral analysis of controlled free attenuating oscillations, it has been argued that simple spectra of deflections can define more than one modal frequencies. To test this scenario, we analyzed 21 controlled excitation events from a certain bridge monitoring survey, focusing on lateral and vertical deflections, recorded both by GNSS and an accelerometer. These events contain a transient and a following oscillation, and they are preceded and followed by intervals of quiescence and ambient vibrations. Spectra for each event, for the lateral and the vertical axis of the bridge, and for and each instrument (GNSS, accelerometer) were computed, normalized to their maximum value, and printed one over the other, in order to produce a single composite spectrum for each of the four sets. In these four sets, there was also marked the true value of modal frequency, derived from free attenuating oscillations. It was found that for high SNR (signal-to-noise ratio) deflections, spectral peaks in both acceleration and displacement spectra differ by up to 0.3 Hz from the true value. For low SNR, defections spectra do not match the true frequency, but acceleration spectra provide a low-precision estimate of the true frequency. This is because various excitation effects (traffic, wind etc.) contribute with numerous peaks in a wide range of frequencies. Reliable estimates of modal frequencies can hence be derived from deflections spectra only if excitation frequencies (mostly traffic and wind) can be filtered along with most measurement noise, on the basis of additional data.

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Consumer Neuroscience Techniques in Advertising Research: A Bibliometric Citation Analysis

Sustainability ◽

10.3390/su13031589 ◽

2021 ◽

Vol 13 (3) ◽

pp. 1589

Author(s):

Juan Sánchez-Fernández ◽

Luis-Alberto Casado-Aranda ◽

Ana-Belén Bastidas-Manzano

Keyword(s):

Self Report ◽

Future Research ◽

Complex Nature ◽

Clear Understanding ◽

Continuous Growth ◽

Main Research ◽

Consumer Neuroscience ◽

Starting Point ◽

Wide Range ◽

Performance Analysis Tools

The limitations of self-report techniques (i.e., questionnaires or surveys) in measuring consumer response to advertising stimuli have necessitated more objective and accurate tools from the fields of neuroscience and psychology for the study of consumer behavior, resulting in the creation of consumer neuroscience. This recent marketing sub-field stems from a wide range of disciplines and applies multiple types of techniques to diverse advertising subdomains (e.g., advertising constructs, media elements, or prediction strategies). Due to its complex nature and continuous growth, this area of research calls for a clear understanding of its evolution, current scope, and potential domains in the field of advertising. Thus, this current research is among the first to apply a bibliometric approach to clarify the main research streams analyzing advertising persuasion using neuroimaging. Particularly, this paper combines a comprehensive review with performance analysis tools of 203 papers published between 1986 and 2019 in outlets indexed by the ISI Web of Science database. Our findings describe the research tools, journals, and themes that are worth considering in future research. The current study also provides an agenda for future research and therefore constitutes a starting point for advertising academics and professionals intending to use neuroimaging techniques.

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A developmentally descriptive method for quantifying shape in gastropod shells

Journal of The Royal Society Interface ◽

10.1098/rsif.2019.0721 ◽

2020 ◽

Vol 17 (163) ◽

pp. 20190721

Author(s):

J. Larsson ◽

A. M. Westram ◽

S. Bengmark ◽

T. Lundh ◽

R. K. Butlin

Keyword(s):

Empirical Studies ◽

Three Dimensional ◽

Shell Shape ◽

Large Set ◽

Littorina Saxatilis ◽

Shape Variation ◽

Gastropod Shell ◽

Geometric Morphometric ◽

Wide Range ◽

Descriptive Method

The growth of snail shells can be described by simple mathematical rules. Variation in a few parameters can explain much of the diversity of shell shapes seen in nature. However, empirical studies of gastropod shell shape variation typically use geometric morphometric approaches, which do not capture this growth pattern. We have developed a way to infer a set of developmentally descriptive shape parameters based on three-dimensional logarithmic helicospiral growth and using landmarks from two-dimensional shell images as input. We demonstrate the utility of this approach, and compare it to the geometric morphometric approach, using a large set of Littorina saxatilis shells in which locally adapted populations differ in shape. Our method can be modified easily to make it applicable to a wide range of shell forms, which would allow for investigations of the similarities and differences between and within many different species of gastropods.

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Energy-minimization multiscale based mesoscale modeling and applications in gas-fluidized catalytic reactors

Reviews in Chemical Engineering ◽

10.1515/revce-2017-0023 ◽

2019 ◽

Vol 35 (8) ◽

pp. 879-915 ◽

Cited By ~ 6

Author(s):

Bona Lu ◽

Yan Niu ◽

Feiguo Chen ◽

Nouman Ahmad ◽

Wei Wang ◽

...

Keyword(s):

Energy Minimization ◽

Fluid Model ◽

Scale Up ◽

Flow Characteristics ◽

Chemical Kinetic ◽

Mesoscale Modeling ◽

Catalytic Reactors ◽

Chemical Kinetic Model ◽

Starting Point ◽

Wide Range

Abstract Gas-solid fluidization is intrinsically dynamic and manifests mesoscale structures spanning a wide range of length and timescales. When involved with reactions, more complex phenomena emerge and thus pose bigger challenges for modeling. As the mesoscale is critical to understand multiphase reactive flows, which the conventional two-fluid model without mesoscale modeling may be inadequate to resolve even using extremely fine grids, this review attempts to demonstrate that the energy-minimization multiscale (EMMS) model could be a starting point to develop such mesoscale modeling. Then, the EMMS-based mesoscale modeling with emphasis on formulation of drag coefficients for different fluidization regimes, modification of mass transfer coefficient, and other extensions are discussed in an attempt to resolve the emerging challenges. Its applications with examples of development of novel fluid catalytic cracking and methanol-to-olefins processes prove that the mesoscale modeling plays a remarkable role in improving the predictions in hydrodynamic behaviors and overall reaction rate. However, the product content primarily depends on the chemical kinetic model itself, suggesting the necessity of an effective coupling between chemical kinetics and flow characteristics. The mesoscale modeling can be believed to accelerate the traditional experimental-based scale-up process with much lower cost in the future.

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Development of Permeability Models for Saturated Fluid Flow across Arrays of Fibre Clusters

Advanced Composites Letters ◽

10.1177/096369350201100303 ◽

2002 ◽

Vol 11 (3) ◽

pp. 096369350201100

Author(s):

E.M. Gravel ◽

T.D. Papathanasiou

Keyword(s):

Analytical Models ◽

Dual Porosity ◽

Hydraulic Permeability ◽

Fibrous Media ◽

Fibre Bundles ◽

Hexagonal Packing ◽

Composites Manufacturing ◽

Starting Point ◽

Wide Range ◽

Flow Through

Dual porosity fibrous media are important in a number of applications, ranging from bioreactor design and transport in living systems to composites manufacturing. In the present study we are concerned with the development of predictive models for the hydraulic permeability ( Kp) of various arrays of fibre bundles. For this we carry out extensive computations for viscous flow through arrays of fibre bundles using the Boundary Element Method (BEM) implemented on a multi-processor computer. Up to 350 individual filaments, arranged in square or hexagonal packing within bundles, which are also arranged in square of hexagonal packing, are included in each simulation. These are simple but not trivial models for fibrous preforms used in composites manufacturing – dual porosity systems characterised by different inter- and intra-tow porosities. The way these porosities affect the hydraulic permeability of such media is currently unknown and is elucidated through our simulations. Following numerical solution of the governing equations, ( Kp) is calculated from the computed flowrate through Darcy's law and is expressed as function of the inter- and intra-tow porosities (φ, φt) and of the filament radius ( Rf). Numerical results are also compared to analytical models. The latter form the starting point in the development of a dimensionless correlation for the permeability of such dual porosity media. It is found that the numerically computed permeabilities follow that correlation for a wide range of φ i, φt and Rf.

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Cellulose and Vanadium Plasmonic Sensor to Measure Ni2+ Ions

Applied Sciences ◽

10.3390/app11072963 ◽

2021 ◽

Vol 11 (7) ◽

pp. 2963

Author(s):

Nur Alia Sheh Omar ◽

Yap Wing Fen ◽

Irmawati Ramli ◽

Umi Zulaikha Mohd Azmi ◽

Hazwani Suhaila Hashim ◽

...

Keyword(s):

Thin Film ◽

Surface Plasmon Resonance ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Signal To Noise Ratio ◽

Affinity Constant ◽

Detection Accuracy ◽

Plasmonic Sensor ◽

Spr Sensor ◽

Resonance Sensor

A novel vanadium–cellulose composite thin film-based on angular interrogation surface plasmon resonance (SPR) sensor for ppb-level detection of Ni(II) ion was developed. Experimental results show that the sensor has a linear response to the Ni(II) ion concentrations in the range of 2–50 ppb with a determination coefficient (R2) of 0.9910. This SPR sensor can attain a maximum sensitivity (0.068° ppb−1), binding affinity constant (1.819 × 106 M−1), detection accuracy (0.3034 degree−1), and signal-to-noise-ratio (0.0276) for Ni(II) ion detection. The optical properties of thin-film targeting Ni(II) ions in different concentrations were obtained by fitting the SPR reflectance curves using the WinSpall program. All in all, the proposed Au/MPA/V–CNCs–CTA thin-film-based surface plasmon resonance sensor exhibits better sensing performance than the previous film-based sensor and demonstrates a wide and promising technology candidate for environmental monitoring applications in the future.

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