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Auditory localization is a fundamental ability that allows to perceive the spatial location of a sound source in the environment. The present work aims to provide a comprehensive overview of the mechanisms and acoustic cues used by the human perceptual system to achieve such accurate auditory localization. Acoustic cues are derived from the physical properties of sound waves, and many factors allow and influence auditory localization abilities. This review presents the monaural and binaural perceptual mechanisms involved in auditory localization in the three dimensions. Besides the main mechanisms of Interaural Time Difference, Interaural Level Difference and Head Related Transfer Function, secondary important elements such as reverberation and motion, are also analyzed. For each mechanism, the perceptual limits of localization abilities are presented. A section is specifically devoted to reference systems in space, and to the pointing methods used in experimental research. Finally, some cases of misperception and auditory illusion are described. More than a simple description of the perceptual mechanisms underlying localization, this paper is intended to provide also practical information available for experiments and work in the auditory field.

The dataset proposed is a collection of pedestrian navigation data sequences combining visual and spatial information. The pedestrian navigation sequences are situations encountered by a pedestrian walking in an urban outdoor environment, such as moving on the sidewalk, navigating through a crowd, or crossing a street when the pedestrian light traffic is green. The acquired data are timestamped provided RGB-D images and are associated with GPS, and inertial data (acceleration, rotation). These recordings were acquired by separate processes, avoiding delays during their capture to guarantee a synchronisation between the moment of acquisition by the sensor and the moment of recording on the system. The acquisition was made in the city of Dijon, France, including narrow streets, wide avenues, and parks.Annotations of the RGB-D are also provided by bounding boxes indicating the position of relevant static or dynamic objects present in a pedestrian area, such as a tree, bench, or person. This pedestrian navigation dataset aims to support the development of smart mobile systems to assist visually impaired people in their daily movements in an outdoor environment. In this context, the visual data and localisation sequences we provide can be used to elaborate the appropriate visual processing methods to extract relevant information about the obstacles and their current positions on the path. Alongside the dataset, a visual-to-auditory substitution method has been employed to convert each image sequence into corresponding stereophonic sound files, allowing for comparison and evaluation. Synthetic sequences associated with the same information set are also provided based on the recordings of a displacement within the 3D model of a real place in Dijon.

Blindness affects millions of people worldwide, leading to difficulties in daily travel and a loss of independence due to a lack of spatial information. This article proposes a new navigation aid to help people with severe blindness reach their destination. Blind people are guided by a short 3D spatialised sound that indicates the target point to follow. This sound is combined with other sonified information on potential obstacles in the vicinity. The proposed system is based on inertial sensors, GPS data, and the cartographic knowledge of pedestrian paths to define the trajectory. In addition, visual clues are used to refine the trajectory with ground floor information and obstacle information using a camera to provide 3D spatial information. The proposed method is based on a deep learning approach. The different neural networks used in this approach are evaluated on datasets that regroup navigations from pedestrians’ point-of-view. This method achieves low latency and real-time processing without relying on remote connections, instead using a low-power embedded GPU target and a multithreaded approach for video processing, sound generation, and acquisition. This system could significantly improve the quality of life and autonomy of blind people, allowing them to reliably and efficiently navigate in their environment.

IntroductionVisual-to-auditory sensory substitution devices are assistive devices for the blind that convert visual images into auditory images (or soundscapes) by mapping visual features with acoustic cues. To convey spatial information with sounds, several sensory substitution devices use a Virtual Acoustic Space (VAS) using Head Related Transfer Functions (HRTFs) to synthesize natural acoustic cues used for sound localization. However, the perception of the elevation is known to be inaccurate with generic spatialization since it is based on notches in the audio spectrum that are specific to each individual. Another method used to convey elevation information is based on the audiovisual cross-modal correspondence between pitch and visual elevation. The main drawback of this second method is caused by the limitation of the ability to perceive elevation through HRTFs due to the spectral narrowband of the sounds.MethodIn this study we compared the early ability to localize objects with a visual-to-auditory sensory substitution device where elevation is either conveyed using a spatialization-based only method (Noise encoding) or using pitch-based methods with different spectral complexities (Monotonic and Harmonic encodings). Thirty eight blindfolded participants had to localize a virtual target using soundscapes before and after having been familiarized with the visual-to-auditory encodings.ResultsParticipants were more accurate to localize elevation with pitch-based encodings than with the spatialization-based only method. Only slight differences in azimuth localization performance were found between the encodings.DiscussionThis study suggests the intuitiveness of a pitch-based encoding with a facilitation effect of the cross-modal correspondence when a non-individualized sound spatialization is used.

Non-governmental organizations play a vital part in the achievement of the Sustainable Development Goals as defined by the United Nations. These Goals also include targets related to noncommunicable diseases. However, non-governmental organizations have played a limited role in this area despite such diseases causing the bulk of morbidity and mortality worldwide. Through their activities, non-governmental organizations should aim to strengthen health systems, yet they often only support these for a single disease. Mali, like many other low- and middle-income countries, is facing an increasing burden of diabetes and a health system not adapted to address this challenge. Santé Diabète, a non-governmental organization based in Mali since 2003, has been working specifically on diabetes, and has developed a wide range of activities to improve the national health system. This paper describes changes in the diabetes environment in Mali between 2004 and 2018 based on two health system assessments carried out using a Rapid Assessment Protocol. Over this period, the health system was strengthened with regard to financing and access to medical products. Leadership and governance, service delivery and health workforce were all improved but still partially rely on sustained support from Santé Diabète. The key lesson from this study is that to be effective in changing the management of noncommunicable diseases in a low- and middle-income country, non-governmental organizations need to play a variety of roles, many of which may change over time.

Auditory localization is a fundamental ability that allows to perceive the spatial location of a sound source in the environment. The present work aims to provide a comprehensive overview of the mechanisms and acoustic cues used by the human perceptual system to achieve such accurate auditory localization. Acoustic cues are derived from the physical properties of sound waves, and many factors allow and influence auditory localization abilities. This review presents the monaural and binaural perceptual mechanisms involved in auditory localization in the three dimensions. Besides the main mechanisms of Interaural Time Difference, Interaural Level Difference and Head Related Transfer Function, secondary important elements such as reverberation and motion, are also analyzed. For each mechanism, the perceptual limits of localization abilities are presented. A section is specifically devoted to reference systems in space, and to the pointing methods used in experimental research. Finally, some cases of misperception and auditory illusion are described. More than a simple description of the perceptual mechanisms underlying localization, this paper is intended to provide also practical information available for experiments and work in the auditory field. [ABSTRACT FROM AUTHOR]

Up-to-date, back pain is among the most prevalent health issues and generally takes its origins from lesions of the annulus fibrosus (AF). While the AF ex vivo mechanical properties are increasingly well understood, in vivo data are still missing. In particular, very few studies have precisely measured the residual strains within the AF and thus the in vivo deformation state of the AF is still miss-interpreted and miss-evaluated. In this work, we propose an original and robust method for the AF residual strains quantification via digital image correlation technics. Ten pig annulus fibrosus were extracted from adjacent vertebrae followed by a radial incision to release the residual strains. The operations were filmed and then analyzed by a custom digital image correlation software in order to quantify the circumferential, radial and shear residual deformations. Our results show that residual strains are of the same order of magnitude than the in vivo one. The average circumferential strains are in tension on the outer periphery ([3.32; 5.94]%) and in compression on the inner periphery ([−6.4; −1.69]%). The mean radial residual strains are essentially in compression ([−10.4; 2.29]%). Locally, radial and circumferential residual strains can reach really large values up to 40% of compression. The mean shear strains remain very small (−0.04% ± 2.88%). This study also shows that circumferential and radial residual strains evolve linearly along the radius and non-linearly along the angle. We propose a simple model to predict their spatial variations. Our results and methods will allow the quantification of more realistic in vivo strains and stresses within the human intervertebral disc.

To refine knowledge about pressurized water reactor fuel melting, the Power to Melt and Maneuverability (P2M) project in the Framework for Irradiation Experiments II (FIDES-II) managed by the Nuclear Energy Agency of the Organisation for Economic Co-operation and Development aims to perform two irradiation tests to reach fuel centerline partial melting using instrumented experimental fuel rodlets irradiated in a pressurized water capsule (PWC) of the Belgian Reactor 2 (BR2) [Studiecentrum voor Kernenergie (SCK CEN), Belgium]. Prior to these experiments, two preliminary tests will be performed in the PWC for qualification purpose toward safety. The experimental rodlets will be instrumented with a fuel centerline thermocouple in the lower part of the fuel and a pressure sensor (PS) in the upper part. An objective of the P2M experiments is to determine the amount of fission gas released from the fuel thanks to the PS measurement. The plenum pressure evolution is known from the measurement, and knowledge of the gas plenum temperature is required to determine the amount of fission gas released from the fuel to the plenum. The gas plenum temperature will depend on natural convection of the PWC coolant, and no temperature measurement will be possible within this gap during the test. This paper describes the setting up of a model of the BR2 PWC equipped with the P2M rodlets based on the coupled NEPTUNE_CFD (multiphase fluid calculation code) and SYRTHES (solid thermal module) simulation tools. Simulations performed thanks to this model allow assessment of the thermal-hydraulic (TH) behavior of the pressurized water in the capsule and the thermal behavior of the rodlet, in particular, regarding the temperature of the gas located in the plenum. For consistency of the results, computations presented in this paper were performed using a single and consistent set of TH models. A mesh sensitivity analysis was carried out for all the studied cases. Simulation results related to the water capsule behavior were found to be in good agreement with the available experimental data. The gas plenum temperature results obtained from this study will be used to assess the fission gas release during the test from the plenum pressure measurements. Overall experimental validation of fission gas release during the test will be possible after the transient test in BR2 based on the postirradiation examination program foreseen on the rodlets at the LECA-STAR facility [Commissariat à l'énergie atomique et aux énergies alternatives (CEA) Cadarache, France]. [ABSTRACT FROM AUTHOR]

CYRANO3 is the thermal-mechanical industrial code developed and used by Electricité de France (EDF) to simulate nuclear fuel rod performance under normal and transient conditions (power ramp tests) in pressurized water reactors and during transport and storage periods, as well. This code has already been successfully used by EDF for the last 30 years to justify normal operations and category 2 transients, covering various types of fuels: UO2, UO2 + gadolinium, mixed oxide, and various claddings, as well those proposed by nuclear fuel suppliers: Zircaloy-4, Zirlo,™ and Optimized Zirlo.™ The CYRANO3 code was recently improved to allow for modeling fuel melting. In this paper, a global overview of CYRANO3's ability to simulate past power-to-melt (P2M) ramps is presented with a focus on recent developments carried out to assess fuel rod behavior under these conditions. CYRANO3 is demonstrated to be a powerful tool to provide reliable values of melted radii. As part of validation of these development works, CYRANO3 calculations have been used to assess two P2M ramp experiments carried out in the BR2 experimental core in Belgium (HBC-4 P2M ramp), and in the R2 experimental core in Sweden (xM3 P2M ramp). The main objectives of the work are to expand knowledge of the thermal-mechanical behavior of high-burnup fuel under P2M ramps by making interpretations of test simulations and to validate newly developed computational models for fuel melting that have been implemented in an extended version of the CYRANO3 fuel code. For both rods, the steady-state irradiation power history was captured and modeling was performed. The key results of the steady-state irradiation modeling are reproduced with fair accuracy by means of CYRANO3 simulations. The results demonstrate the good ability of CYRANO3 to simulate P2M ramps. The melted radii and conditions of failure are well predicted. Calculated melted radius at ramp terminal Linear Heat Generation Rate (LHGR) is in good agreement with the experimental measurements performed after the experiments. [ABSTRACT FROM AUTHOR]

This paper presents the results of the Power To Melt and Maneuverability (P2M) Simulation Exercise on past fuel melting irradiation experiments, organized within the Organisation for Economic Co-operation and Development/Nuclear Energy Agency Framework for IrraDiation ExperimentS (FIDES) framework by the Core Group (CEA, EDF, and SCK‧CEN) and open to all FIDES members. The exercise consisted in simulating two past power ramps where fuel melting was detected: (1) the xM3 staircase power transient [ramp terminal level (RTL) 70 kW‧m−1, average burnup 27 GWd‧tU−1], carried out in 2005 in the R2 reactor at Studsvik (Sweden), where the rodlet maintained its integrity, and (2) the HBC4 fast power transient (RTL 66 kW‧m−1, average burnup 48 GWd‧tU−1), carried out in 1987 in the BR2 reactor at SCK‧CEN (Belgium), where the cladding failed during the experiment. The exercise was joined by 13 organizations from 9 countries using 11 different fuel performance codes. In this paper, the main results of the Simulation Exercise are presented and compared to available postirradiation examinations (PIE) or on-line measurements during the power ramps (fuel and clad diameters, rod elongation, pellet-clad gap, and fission gas release). Since the focus of the Simulation Exercise is on fuel melting assessment, determination of the boundary between melted/nonmelted fuel and the consequent definition of a melting radius from PIE are first discussed. During the HBC4 ramp, fuel melting was predicted by most of the codes despite differences in the melting models. Higher discrepancies were observed for the xM3 rod that can be attributed partly to power uncertainty and partly to the limited capability of the models to describe partial melting of the fuel during this ramp. Finally, possible code developments to improve simulation results are presented. [ABSTRACT FROM AUTHOR]