Intelligibility of bone-conducted speech detected on the scalp

Bone-conduction microphones (BCMs) can detect speakers' voices with high signal-to-noise ratio even under extremely noisy environments like a machine factory or an engine room of a watercraft. BCMs are ordinarily attached to the front of the neck (larynx), therefore, it is sometimes accompanied by discomfort and esthetic problems. In order to solve such problems, we have been developing a novel BCM system built in a helmet, however, characteristics of bone-conducted speech detected on the scalp need to be clarified. In this study, mono-syllable articulations of bone-conducted speech detected at several locations on the head and neck were measured. Also, the speech transmission index (STI), objective measure of signal transmission quality, was calculated. The results indicated that the forehead and the vertex showed better articulation and STI than the mastoid process of the temporal bone, the mandibular condyle, and the occiput. In terms of the gender difference, the forehead and the vertex showed higher scores for the male voice, whereas the cheek showed the highest for the female voice. Additionally, the larynx showed lower scores than others. These results indicated that the attenuation of high-frequency components are smaller at the forehead and the vertex.

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SCaLAr – A surrounding spherical cap loudspeaker array for flexible generation and evaluation of virtual acoustic environments

Acta Acustica ◽

10.1051/aacus/2020014 ◽

2020 ◽

Vol 4 (5) ◽

pp. 19

Author(s):

Florian Pausch ◽

Gottfried Behler ◽

Janina Fels

Keyword(s):

Performance Metrics ◽

Transfer Functions ◽

Finite Impulse Response ◽

Signal To Noise Ratio ◽

Signal Transmission ◽

Sound Field ◽

Low Noise ◽

High Signal ◽

Spherical Cap ◽

Channel Separation

Introduction: Surrounding spherical loudspeaker arrays facilitate the application of various spatial audio reproduction methods and can be used for a broad range of acoustic measurements and perceptual evaluations. Methods: Installed in an anechoic chamber, the design and implementation of such an array of 68 coaxial loudspeakers, sampling a spherical cap with a radius of 1.35 m on an equal-area grid, is presented. A network-based audio backbone enables low-latency signal transmission with low-noise amplifiers providing a high signal-to-noise ratio. To address batch-to-batch variations, the loudspeaker transfer functions were equalised by individually designed 512-taps finite impulse response filters. Time delays and corresponding level adjustments further helped to minimise radial mounting imperfections. Results: The equalised loudspeaker transfer functions measured under ideal conditions and when mounted, their directivity patterns, and in-situ background noise levels satisfy key criteria towards applicability. Advantages and shortcomings of the selected decoders for panning-based techniques, as well as the influence of loudspeaker positioning errors, are analysed in terms of simulated performance metrics. An evaluation of the achievable channel separation allows deriving recommendations of feasible subset layouts for loudspeaker-based binaural reproduction. Conclusion: The combination of electroacoustic properties, simulated sound field synthesis performance and measured channel separation classifies the system as suitable for its target applications.

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A compact guided-wave EMAT with pulsed electromagnet for ferromagnetic tube inspection

International Journal of Applied Electromagnetics and Mechanics ◽

10.3233/jae-209409 ◽

2020 ◽

Vol 64 (1-4) ◽

pp. 951-958

Author(s):

Tianhao Liu ◽

Yu Jin ◽

Cuixiang Pei ◽

Jie Han ◽

Zhenmao Chen

Keyword(s):

Power Plants ◽

Signal To Noise Ratio ◽

Small Diameter ◽

Performance Testing ◽

Guided Wave ◽

High Signal ◽

Receiver Coil ◽

Signal To Noise ◽

Corrosion Defects

Small-diameter tubes that are widely used in petroleum industries and power plants experience corrosion during long-term services. In this paper, a compact inserted guided-wave EMAT with a pulsed electromagnet is proposed for small-diameter tube inspection. The proposed transducer is noncontact, compact with high signal-to-noise ratio and unattractive to ferromagnetic tubes. The proposed EMAT is designed with coils-only configuration, which consists of a pulsed electromagnet and a meander pulser/receiver coil. Both the numerical simulation and experimental results validate its feasibility on generating and receiving L(0,2) mode guided wave. The parameters for driving the proposed EMAT are optimized by performance testing. Finally, feasibility on quantification evaluation for corrosion defects was verified by experiments.

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Application of Novel Low Current OBIRCH Amplifier and Nanoprobing to Identify Subtle Leakages in Advanced Node Technologies

10.31399/asm.cp.istfa2018p0303 ◽

2018 ◽

Author(s):

Satish Kodali ◽

Liangshan Chen ◽

Yuting Wei ◽

Tanya Schaeffer ◽

Chong Khiam Oh

Keyword(s):

Signal To Noise Ratio ◽

Semiconductor Industry ◽

Fault Isolation ◽

Ring Oscillator ◽

High Signal ◽

The Novel ◽

Resistance Change ◽

Three Samples ◽

Relative Threshold ◽

First Time

Abstract Optical beam induced resistance change (OBIRCH) is a very well-adapted technique for static fault isolation in the semiconductor industry. Novel low current OBIRCH amplifier is used to facilitate safe test condition requirements for advanced nodes. This paper shows the differences between the earlier and novel generation OBIRCH amplifiers. Ring oscillator high standby leakage samples are analyzed using the novel generation amplifier. High signal to noise ratio at applied low bias and current levels on device under test are shown on various samples. Further, a metric to demonstrate the SNR to device performance is also discussed. OBIRCH analysis is performed on all the three samples for nanoprobing of, and physical characterization on, the leakage. The resulting spots were calibrated and classified. It is noted that the calibration metric can be successfully used for the first time to estimate the relative threshold voltage of individual transistors in advanced process nodes.

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VS2 as saturable absorber for Q-switched pulse generation

Nanophotonics ◽

10.1515/nanoph-2020-0128 ◽

2020 ◽

Vol 9 (8) ◽

pp. 2569-2576 ◽

Cited By ~ 4

Author(s):

Lu Li ◽

Lihui Pang ◽

Qiyi Zhao ◽

Yao Wang ◽

Wenjun Liu

Keyword(s):

Saturable Absorber ◽

Nonlinear Optical ◽

Modulation Depth ◽

Signal To Noise Ratio ◽

Transition Metal Dichalcogenides ◽

Laser Cavity ◽

Pulse Generation ◽

High Signal ◽

Power Pulse ◽

Metal Dichalcogenides

AbstractTransition metal dichalcogenides have been widely utilized as nonlinear optical materials for laser pulse generation applications. Herein, we study the nonlinear optical properties of a VS2-based optical device and its application as a new saturable absorber (SA) for high-power pulse generation. Few-layer VS2 nanosheets are deposited on the tapered region of a microfiber to form an SA device, which shows a modulation depth of 40.52%. After incorporating the microfiber-VS2 SA into an Er-doped fiber laser cavity, passively Q-switched pulse trains could be obtained with repetition rates varying from 95 to 233 kHz. Under the pump power of 890 mW, the largest output power and shortest pulse duration are measured to be 43 mW and 854 ns, respectively. The high signal-to-noise ratio of 60 dB confirms the excellent stability of the Q-switching state. To the best of our knolowdge, this is the first illustration of using VS2 as an SA. Our experimental results demonstrate that VS2 nanomaterials have a large potential for nonlinear optics applications.

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Detection and localization of multiple small damages in beam

Advances in Mechanical Engineering ◽

10.1177/1687814020987329 ◽

2021 ◽

Vol 13 (1) ◽

pp. 168781402098732

Author(s):

Ayisha Nayyar ◽

Ummul Baneen ◽

Syed Abbas Zilqurnain Naqvi ◽

Muhammad Ahsan

Keyword(s):

Frequency Response ◽

Natural Frequencies ◽

Signal To Noise Ratio ◽

Moving Average ◽

A Priori ◽

Damage Index ◽

High Signal ◽

Frequency Range ◽

Spatial Locality ◽

System Frequency

Localizing small damages often requires sensors be mounted in the proximity of damage to obtain high Signal-to-Noise Ratio in system frequency response to input excitation. The proximity requirement limits the applicability of existing schemes for low-severity damage detection as an estimate of damage location may not be known a priori. In this work it is shown that spatial locality is not a fundamental impediment; multiple small damages can still be detected with high accuracy provided that the frequency range beyond the first five natural frequencies is utilized in the Frequency response functions (FRF) curvature method. The proposed method presented in this paper applies sensitivity analysis to systematically unearth frequency ranges capable of elevating damage index peak at correct damage locations. It is a baseline-free method that employs a smoothing polynomial to emulate reference curvatures for the undamaged structure. Numerical simulation of steel-beam shows that small multiple damages of severity as low as 5% can be reliably detected by including frequency range covering 5–10th natural frequencies. The efficacy of the scheme is also experimentally validated for the same beam. It is also found that a simple noise filtration scheme such as a Gaussian moving average filter can adequately remove false peaks from the damage index profile.

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Understanding PI-QUAL for prostate MRI quality: a practical primer for radiologists

Insights into Imaging ◽

10.1186/s13244-021-00996-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Francesco Giganti ◽

Alex Kirkham ◽

Veeru Kasivisvanathan ◽

Marianthi-Vasiliki Papoutsaki ◽

Shonit Punwani ◽

...

Keyword(s):

Diffusion Weighted Imaging ◽

Signal To Noise Ratio ◽

High Signal ◽

Diagnostic Quality ◽

Prostate Mri ◽

Prostate Imaging ◽

Dynamic Contrast Enhanced ◽

Diffusion Weighted ◽

Contrast Enhanced

AbstractProstate magnetic resonance imaging (MRI) of high diagnostic quality is a key determinant for either detection or exclusion of prostate cancer. Adequate high spatial resolution on T2-weighted imaging, good diffusion-weighted imaging and dynamic contrast-enhanced sequences of high signal-to-noise ratio are the prerequisite for a high-quality MRI study of the prostate. The Prostate Imaging Quality (PI-QUAL) score was created to assess the diagnostic quality of a scan against a set of objective criteria as per Prostate Imaging-Reporting and Data System recommendations, together with criteria obtained from the image. The PI-QUAL score is a 1-to-5 scale where a score of 1 indicates that all MR sequences (T2-weighted imaging, diffusion-weighted imaging and dynamic contrast-enhanced sequences) are below the minimum standard of diagnostic quality, a score of 3 means that the scan is of sufficient diagnostic quality, and a score of 5 implies that all three sequences are of optimal diagnostic quality. The purpose of this educational review is to provide a practical guide to assess the quality of prostate MRI using PI-QUAL and to familiarise the radiologist and all those involved in prostate MRI with this scoring system. A variety of images are also presented to demonstrate the difference between suboptimal and good prostate MR scans.

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Imbalanced post- and extrasynaptic SHANK2A functions during development affect social behavior in SHANK2-mediated neuropsychiatric disorders

Molecular Psychiatry ◽

10.1038/s41380-021-01140-y ◽

2021 ◽

Author(s):

Ahmed Eltokhi ◽

Miguel A. Gonzalez-Lozano ◽

Lars-Lennart Oettl ◽

Andrey Rozov ◽

Claudia Pitzer ◽

...

Keyword(s):

Synaptic Plasticity ◽

Social Interaction ◽

Social Behavior ◽

Ampa Receptors ◽

Signal To Noise Ratio ◽

Signal Transmission ◽

Neuropsychiatric Disorders ◽

Autism Spectrum ◽

Strong Impact ◽

Odor Processing

AbstractMutations in SHANK genes play an undisputed role in neuropsychiatric disorders. Until now, research has focused on the postsynaptic function of SHANKs, and prominent postsynaptic alterations in glutamatergic signal transmission have been reported in Shank KO mouse models. Recent studies have also suggested a possible presynaptic function of SHANK proteins, but these remain poorly defined. In this study, we examined how SHANK2 can mediate electrophysiological, molecular, and behavioral effects by conditionally overexpressing either wild-type SHANK2A or the extrasynaptic SHANK2A(R462X) variant. SHANK2A overexpression affected pre- and postsynaptic targets and revealed a reversible, development-dependent autism spectrum disorder-like behavior. SHANK2A also mediated redistribution of Ca2+-permeable AMPA receptors between apical and basal hippocampal CA1 dendrites, leading to impaired synaptic plasticity in the basal dendrites. Moreover, SHANK2A overexpression reduced social interaction and increased the excitatory noise in the olfactory cortex during odor processing. In contrast, overexpression of the extrasynaptic SHANK2A(R462X) variant did not impair hippocampal synaptic plasticity, but still altered the expression of presynaptic/axonal signaling proteins. We also observed an attention-deficit/hyperactivity-like behavior and improved social interaction along with enhanced signal-to-noise ratio in cortical odor processing. Our results suggest that the disruption of pre- and postsynaptic SHANK2 functions caused by SHANK2 mutations has a strong impact on social behavior. These findings indicate that pre- and postsynaptic SHANK2 actions cooperate for normal neuronal function, and that an imbalance between these functions may lead to different neuropsychiatric disorders.

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Narrow-frequency sharp-angular filters using all-dielectric cascaded meta-gratings

Nanophotonics ◽

10.1515/nanoph-2020-0141 ◽

2020 ◽

Vol 9 (10) ◽

pp. 3443-3450 ◽

Cited By ~ 1

Author(s):

Wei-Nan Liu ◽

Rui Chen ◽

Wei-Yi Shi ◽

Ke-Bo Zeng ◽

Fu-Li Zhao ◽

...

Keyword(s):

Thin Film ◽

Signal To Noise Ratio ◽

Incident Angle ◽

Design Strategy ◽

Transmission Peak ◽

High Signal ◽

Waveguide Array ◽

Signal To Noise ◽

Center Wavelength ◽

Noise Ratio

AbstractSelective transmission or filtering always responds to either frequency or incident angle, so as hardly to maximize signal-to-noise ratio in communication, detection and sensing. Here, we propose compact meta-filters of narrow-frequency sharp-angular transmission peak along with broad omnidirectional reflection sidebands, in all-dielectric cascaded subwavelength meta-gratings. The inherent collective resonance of waveguide-array modes and thin film approximation of meta-grating are employed as the design strategy. A unity transmission peak, locating at the incident angle of 44.4° and the center wavelength of 1550 nm, is demonstrated in a silicon meta-filter consisting of two-layer silicon rectangular meta-grating. These findings provide possibilities in cascaded meta-gratings spectroscopic design and alternative utilities for high signal-to-noise ratio applications in focus-free spatial filtering and anti-noise systems in telecommunications.

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Mid-infrared photoacoustic gas monitoring driven by a gas-filled hollow-core fiber laser

Scientific Reports ◽

10.1038/s41598-021-83041-2 ◽

2021 ◽

Vol 11 (1) ◽

Cited By ~ 1

Author(s):

Yazhou Wang ◽

Yuyang Feng ◽

Abubakar I. Adamu ◽

Manoj K. Dasa ◽

J. E. Antonio-Lopez ◽

...

Keyword(s):

Fiber Laser ◽

Signal To Noise Ratio ◽

High Sensitivity ◽

Laser Source ◽

High Signal ◽

Mid Infrared ◽

Raman Fiber Laser ◽

Custom Made ◽

Core Fiber ◽

Detection Technologies

AbstractDevelopment of novel mid-infrared (MIR) lasers could ultimately boost emerging detection technologies towards innovative spectroscopic and imaging solutions. Photoacoustic (PA) modality has been heralded for years as one of the most powerful detection tools enabling high signal-to-noise ratio analysis. Here, we demonstrate a novel, compact and sensitive MIR-PA system for carbon dioxide (CO2) monitoring at its strongest absorption band by combining a gas-filled fiber laser and PA technology. Specifically, the PA signals were excited by a custom-made hydrogen (H2) based MIR Raman fiber laser source with a pulse energy of ⁓ 18 μJ, quantum efficiency of ⁓ 80% and peak power of ⁓ 3.9 kW. A CO2 detection limit of 605 ppbv was attained from the Allan deviation. This work constitutes an alternative method for advanced high-sensitivity gas detection.

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A Self-Powered and Highly Accurate Vibration Sensor Based on Bouncing-Ball Triboelectric Nanogenerator for Intelligent Ship Machinery Monitoring

Micromachines ◽

10.3390/mi12020218 ◽

2021 ◽

Vol 12 (2) ◽

pp. 218

Author(s):

Taili Du ◽

Xusheng Zuo ◽

Fangyang Dong ◽

Shunqi Li ◽

Anaeli Elibariki Mtui ◽

...

Keyword(s):

Signal To Noise Ratio ◽

Work Conditions ◽

Copper Electrode ◽

Vibration Sensor ◽

High Signal ◽

Triboelectric Nanogenerator ◽

Vibration Exciter ◽

Bouncing Ball ◽

3D Printed ◽

Self Powered

With the development of intelligent ship, types of advanced sensors are in great demand for monitoring the work conditions of ship machinery. In the present work, a self-powered and highly accurate vibration sensor based on bouncing-ball triboelectric nanogenerator (BB-TENG) is proposed and investigated. The BB-TENG sensor consists of two copper electrode layers and one 3D-printed frame filled with polytetrafluoroethylene (PTFE) balls. When the sensor is installed on a vibration exciter, the PTFE balls will continuously bounce between the two electrodes, generating a periodically fluctuating electrical signals whose frequency can be easily measured through fast Fourier transform. Experiments have demonstrated that the BB-TENG sensor has a high signal-to-noise ratio of 34.5 dB with mean error less than 0.05% at the vibration frequency of 10 Hz to 50 Hz which covers the most vibration range of the machinery on ship. In addition, the BB-TENG can power 30 LEDs and a temperature sensor by converting vibration energy into electricity. Therefore, the BB-TENG sensor can be utilized as a self-powered and highly accurate vibration sensor for condition monitoring of intelligent ship machinery.

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