Anomalous sound event detection: A survey of machine learning based methods and applications

With the development of multi-modal man-machine interaction, audio signal analysis is gaining importance in a field traditionally dominated by video. In particular, anomalous sound event detection offers novel options to improve audio-based man-machine interaction, in many useful applications such as surveillance systems, industrial fault detection and especially safety monitoring, either indoor or outdoor. Event detection from audio can fruitfully integrate visual information and can outperform it in some respects, thus representing a complementary perceptual modality. However, it also presents specific issues and challenges. In this paper, a comprehensive survey of anomalous sound event detection is presented, covering various aspects of the topic, ?.e.feature extraction methods, datasets, evaluation metrics, methods, applications, and some open challenges and improvement ideas that have been recently raised in the literature.

     

Numerical research of double‐diffusive natural convection in elliptical cylinders: Effect of thermal Rayleigh number

This paper is the first part of a two‐part study, and it presented numerical research of double‐diffusive natural convection within an annulus area, situated in two horizontal confocal elliptic solids charged by a Newtonian fluid. The elliptical coordinates were used to transform the physical domain into a rectangular one. To resolve the governing equations and the boundary layer conditions, a calculator code based on the finite volume approach was developed. The details of the influences of thermal Rayleigh number on heat and mass transfer were investigated. Results obtained were compared with those existing in other reasearch works.     

Cross Pharmacological,Biochemical and Computational Studies of a Human Kv3.1b Inhibitor from Androctonus australis Venom

The voltage-gated K⁺ channels Kv3.1 display fast activation and deactivation kinetics and are known to have a crucial contribution to the fast-spiking phenotype of certain neurons. AahG50, as a natural product extracted from Androctonus australis hector venom, inhibits selectively Kv3.1 channels. In the present study, we focused on the biochemical and pharmacological characterization of the component in AahG50 scorpion venom that potently and selectively blocks the Kv3.1 channels. We used a combined optimization through advanced biochemical purification and patch-clamp screening steps to characterize the peptide in AahG50 active on Kv3.1 channels. We described the inhibitory effect of a toxin on Kv3.1 unitary current in black lipid bilayers. In silico, docking experiments are used to study the molecular details of the binding. We identified the first scorpion venom peptide inhibiting Kv3.1 current at 170 nM. This toxin is the alpha-KTx 15.1, which occludes the Kv3.1 channel pore by means of the lysine 27 lateral chain. This study highlights, for the first time, the modulation of the Kv3.1 by alpha-KTx 15.1, which could be an interesting starting compound for developing therapeutic biomolecules against Kv3.1-associated diseases.     

Free radical fast photo-cured gate dielectric for top-gate polymer field effect transistors

We demonstrated top-gate organic field effect transistors (OFETs) made with free radical photo-cured polymer gate dielectrics and poly(3-hexylthiophene). We introduced a new approach of cross linking dielectric polymers in OFETs by using acrylate monomers cured with UV irradiation directly on the semiconductor. Three different blends were formulated: one self-initiating acrylate oligomer and two epoxy acrylate monomers mixed with 4-phenylbenzophenone as photo initiator and N-methyldiethanolamine as amine synergist. Thin films of these blends were cured in air within one minute. The curing process was monitored with FT-IR spectroscopy and the effect of a wetting agent was studied by measuring the CV characteristics of metal–insulator-semiconductor (MIS) structures made with these formulations. OFETs made with the demonstrated formulations showed high on/off ratios (10⁵–10⁶) and low sub-threshold slopes (0.44–1.42 V/dec).     

Analysis of a new annular multi-slits antenna using wave concept iterative process in cylindrical coordinates

In this paper, a new antenna for satellite applications is proposed. This antenna is designed to operate at any frequency desired. It consists of a circular microstrip patch antenna which incorporates concentric annular slits, and it is printed on a grounded substrate. The details of the proposed antenna design and numerical results are presented and discussed. The wave concept iterative procedure in cylindrical coordinates is used to analyze this new antenna. Using the proposed procedure, less computing time and memory are needed to calculate the electromagnetic parameters of the annular multi-slits antenna.     

The transverse elastic properties of chiral honeycombs

This work describes the out-of-plane linear elastic mechanical properties of trichiral, tetrachiral and hexachiral honeycomb configurations. Analytical models are developed to calculate the transverse Young’s modulus and the Voigt and Reuss bounds for the transverse shear stiffness. Finite Element models are developed to validate the analytical results, and to identify the dependence of the transverse shear stiffness vs. the gauge thickness of the honeycombs. The models are then validated with experimental results from flatwise compressive and simple shear tests on samples produced with rapid prototype (RP)-based techniques.     

Numerical and Experimental Study of the Impact of Key Parameters on a PVT Air Collector: Mass Flow Rate and Duct Depth

The PVT-air solar system simultaneously generates electrical and thermal energy. Therefore, increasing the cost-effectiveness of the system requires an appropriate choice of key parameters such as mass flow rate and air channel depth. In this paper, a PVT-air kit of a single module with a 30° slope was used to measure photovoltaic electricity and air heating power in the city of Sfax, Tunisia. Besides, a computer method was implemented using the ANSYS Fluent 17.0 software and the MATLAB program to analyse the properties of the airflow and to characterise PVT-air yields under different mass flow rates and depths. From the comparison of numerical and experimental data, the numerical method was validated with a good agreement. Indeed, we have found that increasing of the airflow rate improves the thermal efficiency with a slight change on electrical output. However, the reduction in depth shows an improvement on thermal efficiency and a negligible effect on electrical efficiency. Also, we have presented the thermal and electrical performance of PVT-air as a function of the key parameters with the Hottel-Whillier-Bliss formulation.     

Improved preventive maintenance in the framework of forecasting problem under subcontractor constraint

The paper presents a new improved preventive maintenance strategy for a forecasting problem of production and maintenance optimisation under subcontractor constraint. In order to satisfy the customer, the manufacturing system consists of a principal machine M₁ and called upon subcontractor machine M_s. Knowing that both machines are subjected to random failures, failure rate of main machine increases with time and according to production rates. An improved preventive maintenance strategy is used for control of the machine M₁, whereas subcontractor machine M_s is uncontrollable from preventive maintenance point of view. An analytic formulation of problem has been proposed in order to determine the economical production plans for M₁ and M_s. An improved maintenance strategy (IMS) is developed in order to minimise the total production loss, when the subcontractor machine is unavailable. It consists of determining the best time to perform preventive maintenance actions taking into account production rates, history of M₁ and the state of subcontractor machine M_s. Numerical results and sensitivity analysis are presented to highlight the performance measure and the usefulness of the IMS.     

Emotional speaker recognition in real life conditions using multiple descriptors and i-vector speaker modeling technique

Multimedia Tools and Applications - Emotional speaker recognition under real life conditions becomes an urgent need for several applications. This paper proposes a novel approach using multiple...