Bibliografie tematiche / Sound zone

Indice

Articoli di riviste
Tesi
Libri
Capitoli di libri
Atti di convegni
Rapporti di organizzazioni

Letteratura scientifica selezionata sul tema "Sound zone"

Autore: Grafiati

Pubblicato: 14 settembre 2024

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili

Scegli il tipo di fonte:

Consulta la lista di attuali articoli, libri, tesi, atti di convegni e altre fonti scientifiche attinenti al tema "Sound zone".

Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.

Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.

Articoli di riviste sul tema "Sound zone"

Huang, Yang, Sipei Zhao e Jing Lu. "Acoustic contrast control with a sound intensity constraint for personal sound systems". Journal of the Acoustical Society of America 155, n. 2 (1 febbraio 2024): 879–90. http://dx.doi.org/10.1121/10.0024617.

Testo completo

Abstract (sommario):

Personal sound systems have received significant research interest in the past two decades due to their promising applications in a variety of scenarios. Various methods have been proposed to generate personal sound zones, most of which are based on sound pressure manipulation in both the acoustically bright and dark zones. Since sound intensity is closely related to human perception of sound localization, this paper proposes an acoustic contrast control method with a sound intensity constraint to increase the spatial planarity in the bright zone. In the proposed method, the sound intensity in the bright zone is projected to a specific direction while the sound pressure level in the dark zone is minimized. Simulations and experiments are carried out to compare the proposed method with the existing planarity control and pressure matching methods in terms of acoustic contrast, array effort, and planarity. The results demonstrate that the proposed method improves the planarity in the bright zone compared to existing planarity control method, while exhibitig a higher acoustic contrast and a lower array effort than the pressure matching method.

Gli stili APA, Harvard, Vancouver, ISO e altri

Lee, Hsiao Mun, Heow Pueh Lee e Zhiyang Liu. "Acoustical Environment Studies in the Modern Urban University Campuses". Acoustics 4, n. 1 (7 gennaio 2022): 14–25. http://dx.doi.org/10.3390/acoustics4010002.

Testo completo

Abstract (sommario):

The quality of the acoustic environments at Xi’an Jiatong-Liverpool University (XJTLU) and Soochow University (Dushuhu Campus, SUDC) in Suzhou City were investigated in the present work through real-time noise level measurements and questionnaire surveys. Before commencing the measurements and surveys, these two campuses’ sound sources were summarized and classified into four categories through on-site observation: human-made, machinery, living creatures, and natural physical sounds. For the zones near the main traffic road, with a high volume of crowds and surrounded by a park, sound from road vehicles, humans talking, and birds/insects were selected by the interviewees as the major sound sources, respectively. Only zone 3 (near to a park) at XJTLU could be classified as A zone (noise level < 55 dBA) with an excellent quality acoustical environment. All other zones had either good or average quality acoustical environments, except zone 1 (near to main traffic road) at XJTLU, with a fair-quality acoustical environment.

Gli stili APA, Harvard, Vancouver, ISO e altri

Jeong, Jeong-Ho. "Prediction and Evaluation of Emergency Broadcasting Sound and Speech Intelligibility for Safety Zones in High-rise Buildings". Fire Science and Engineering 34, n. 6 (31 dicembre 2020): 37–43. http://dx.doi.org/10.7731/kifse.91d2fd5b.

Testo completo

Abstract (sommario):

As construction of high-rise buildings is increasing, the installation of a fire safety zone for the safe evacuation of residents has become mandatory. Even for building complexes with an underground connection between 30 and 49 stories, a fire safety zone must be installed when the residential density exceeds 1.5 people per square meter. In the fire safety zone, an automatic fire detection system and a system to assist radio communication must be installed. In addition, an emergency broadcasting system must be installed to announce the fire situation and to guide the safe evacuation of the residents. The fire safety zone was constructed with non-combustible material to minimize flames or smoke and was furnished to maintain a very low fire load. However, non-combustible materials have very low sound absorption characteristics; therefore, they usually reflect the sound energy into the spaces. In spaces consisting of sound reflective materials, the emergency broadcasting sounds reverberated, making it difficult to understand the meaning of the broadcasted sound. In this study, the room acoustics characteristics for fire safety zones in a high-rise building, represented as reverberation time and speech transmission index, were predicted using a certified room acoustics simulation method and evaluation of speech intelligibility. As a result of predicting the acoustic characteristics of the safety zone, it was found that the space had quite long reverberation and speech intelligibility was low, making it difficult to clearly transmit the emergency broadcast sound. When a safety zone was set up in a part of the machinery room, it was confirmed that it was difficult to clearly transmit the emergency broadcast sound, even when the background noise level was louder than 70 dB(A). To deliver a clear emergency broadcast sound in the safety zone, it is necessary to use inorganic sound-absorbing materials and to properly block noise in the machine room. In addition, it is necessary to establish guidelines for regulation of the speech transmission index for emergency broadcasting systems.

Gli stili APA, Harvard, Vancouver, ISO e altri

Wen, Xin, Haijun Wu, Yilong Fan e Weikang Jiang. "A multizone sound field reproduction method based on modal domain analysis". INTER-NOISE and NOISE-CON Congress and Conference Proceedings 268, n. 5 (30 novembre 2023): 3916–21. http://dx.doi.org/10.3397/in_2023_0559.

Testo completo

Abstract (sommario):

Multizone sound field reproduction for synthesizing desired sound fields over multiple spatial zones has been widely studied. In the traditional multizone sound field reproduction modal domain method, the final loudspeaker weights required to reproduce the desired sound field are obtained by translating the optimal equivalent global modal domain coefficients, which is susceptible to the characteristics and location of the loudspeakers and reduces the reproduction performance. This paper investigates a multizone sound field reproduction in modal domain for directly obtaining the reproducing loudspeaker weights. The optimization model is formulated to the objective of reproducing a desired sound field within the bright zone and with constraints on acoustic energy in the dark zone. The loudspeaker weights for reproducing the desired sound field are solved by the CVX toolbox. The numerical simulation results indicate that the proposed method is superior to the acoustic contrast control method and the mode matching method in terms of the accuracy of the reproduction desired sound field in the bright zone and the acoustic contrast between the bright and dark zones.

Gli stili APA, Harvard, Vancouver, ISO e altri

Kim, Deliya, Eldad Jitzhak Avital e Touvia Miloh. "Sound Scattering and Its Reduction by a Janus Sphere Type". Advances in Acoustics and Vibration 2014 (18 settembre 2014): 1–11. http://dx.doi.org/10.1155/2014/392138.

Testo completo

Abstract (sommario):

Sound scattering by a Janus sphere type is considered. The sphere has two surface zones: a soft surface of zero acoustic impedance and a hard surface of infinite acoustic impedance. The zones are arranged such that axisymmetry of the sound field is preserved. The equivalent source method is used to compute the sound field. It is shown that, by varying the sizes of the soft and hard zones on the sphere, a significant reduction can be achieved in the scattered acoustic power and upstream directivity when the sphere is near a free surface and its soft zone faces the incoming wave and vice versa for a hard ground. In both cases the size of the sphere’s hard zone is much larger than that of its soft zone. The boundary location between the two zones coincides with the location of a zero pressure line of the incoming standing sound wave, thus masking the sphere within the sound field reflected by the free surface or the hard ground. The reduction in the scattered acoustic power diminishes when the sphere is placed in free space. Variations of the scattered acoustic power and directivity with the sound frequency are also given and discussed.

Gli stili APA, Harvard, Vancouver, ISO e altri

Erbe, Christine, David Peel, Joshua N. Smith e Renee P. Schoeman. "Marine Acoustic Zones of Australia". Journal of Marine Science and Engineering 9, n. 3 (19 marzo 2021): 340. http://dx.doi.org/10.3390/jmse9030340.

Testo completo

Abstract (sommario):

Underwater sound is modelled and mapped for purposes ranging from localised environmental impact assessments of individual offshore developments to large-scale marine spatial planning. As the area to be modelled increases, so does the computational effort. The effort is more easily handled if broken down into smaller regions that could be modelled separately and their results merged. The goal of our study was to split the Australian maritime Exclusive Economic Zone (EEZ) into a set of smaller acoustic zones, whereby each zone is characterised by a set of environmental parameters that vary more across than within zones. The environmental parameters chosen reflect the hydroacoustic (e.g., water column sound speed profile), geoacoustic (e.g., sound speeds and absorption coefficients for compressional and shear waves), and bathymetric (i.e., seafloor depth and slope) parameters that directly affect the way in which sound propagates. We present a multivariate Gaussian mixture model, modified to handle input vectors (sound speed profiles) of variable length, and fitted by an expectation-maximization algorithm, that clustered the environmental parameters into 20 maritime acoustic zones corresponding to 28 geographically separated locations. Mean zone parameters and shape files are available for download. The zones may be used to map, for example, underwater sound from commercial shipping within the entire Australian EEZ.

Gli stili APA, Harvard, Vancouver, ISO e altri

Merzenich, Michael. "Seeing in the sound zone". Nature 404, n. 6780 (aprile 2000): 820–21. http://dx.doi.org/10.1038/35009174.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Westervelt, Peter J. "Scattering of sound by sound within the interaction zone". Journal of the Acoustical Society of America 96, n. 5 (novembre 1994): 3320. http://dx.doi.org/10.1121/1.410764.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Du, Bokai, e Qun Yan. "Multizone sound field reproduction based on equivalent source decomposition". INTER-NOISE and NOISE-CON Congress and Conference Proceedings 268, n. 8 (30 novembre 2023): 880–89. http://dx.doi.org/10.3397/in_2023_0140.

Testo completo

Abstract (sommario):

Multizone sound field reproduction attempts to recreate a desired sound field on the bright zone and reduce sound field energy on the dark zone. Conventional pressure-matching based multizone reproduction method is only able to control sound pressures at limited number of measurement points on the bright zones which are equal to target sound field recording points number. The reproduction performance is strongly affected by the number of recording points. In this paper, a reproduction method based on the sparse plane wave decomposition method is proposed to improve the reproduction performance when the target sound field is generated by one or a small number of sources. The recorded target sound field is decomposed into a group of plane waves. Loudspeaker weights are calculated as a summation precalculated corresponding plane waves weights. A simulation is conducted in a room to verify the performance of the proposed method. Compared with the conventional method, the proposed method achieves better sound field reproduction accuracy on the bright zone and similar acoustic contrast performance.

Gli stili APA, Harvard, Vancouver, ISO e altri

Lin, Yi-Wei, e Gee-Pinn James Too. "A Parametric Study of Sound Focusing in Shallow Water by Using Acoustic Contrast Control". Journal of Computational Acoustics 22, n. 04 (18 settembre 2014): 1450012. http://dx.doi.org/10.1142/s0218396x1450012x.

Testo completo

Abstract (sommario):

Acoustic contrast control is a sound focusing technique applied to personal audio system devices to provide the optimal sound contrast for increasing or decreasing the potential sound energy of a specific area. In this study, acoustic contrast control was developed for sound focusing in shallow water. The advantage of this technique is the establishment of two zones: a bright zone around the user and a dark zone for other regions. In the acoustic contrast control process, computational ocean acoustics are used to calculate the Green's function between the source point and the field point. The effects of environmental parameters, which comprised the number of control sources, transmission frequency, control distances between sources and control zone of a geometric location were simulated. The results show that acoustic contrast control is an effective approach for sound focusing in shallow water that can increase the potential sound energy of a specific area. Employing this technique can also enhance underwater communications by using frequency-shift keying modulation for cross-talking applications.

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Tesi sul tema "Sound zone"

Olik, Marek. "Personal sound zone reproduction with room reflections". Thesis, University of Surrey, 2015. http://epubs.surrey.ac.uk/807178/.

Testo completo

Abstract (sommario):

Loudspeaker-based sound systems, capable of a convincing reproduction of different audio streams to listeners in the same acoustic enclosure, are a convenient alternative to headphones. Such systems aim to generate "sound zones" in which target sound programmes are to be reproduced with minimum interference from any alternative programmes. This can be achieved with appropriate filtering of the source (loudspeaker) signals, so that the target sound's energy is directed to the chosen zone while being attenuated elsewhere. The existing methods are unable to produce the required sound energy ratio (acoustic contrast) between the zones with a small number of sources when strong room reflections are present. Optimization of parameters is therefore required for systems with practical limitations to improve their performance in reflective acoustic environments. One important parameter is positioning of sources with respect to the zones and room boundaries. The first contribution of this thesis is a comparison of the key sound zoning methods implemented on compact and distributed geometrical source arrangements. The study presents previously unpublished detailed evaluation and ranking of such arrangements for systems with a limited number of sources in a reflective acoustic environment similar to a domestic room. Motivated by the requirement to investigate the relationship between source positioning and performance in detail, the central contribution of this thesis is a study on optimizing source arrangements when strong individual room reflections occur. Small sound zone systems are studied analytically and numerically to reveal relationships between the geometry of source arrays and performance in terms of acoustic contrast and array effort (related to system efficiency). Three novel source position optimization techniques are proposed to increase the contrast, and geometrical means of reducing the effort are determined. Contrary to previously published case studies, this work presents a systematic examination of the key problem of first order reflections and proposes general optimization techniques, thus forming an important contribution. The remaining contribution considers evaluation and comparison of the proposed techniques with two alternative approaches to sound zone generation under reflective conditions: acoustic contrast control (ACC) combined with anechoic source optimization and sound power minimization (SPM). The study provides a ranking of the examined approaches which could serve as a guideline for method selection for rooms with strong individual reflections.

Gli stili APA, Harvard, Vancouver, ISO e altri

Coleman, Philip. "Loudspeaker array processing for personal sound zone reproduction". Thesis, University of Surrey, 2014. http://epubs.surrey.ac.uk/805527/.

Testo completo

Abstract (sommario):

Sound zone reproduction facilitates listeners wishing to consume personal audio content within the same acoustic enclosure by filtering loudspeaker signals to create constructive and destructive interference in different spatial regions. Published solutions to the sound zone problem are derived from areas such as sound field synthesis and beamforming. The first contribution of this thesis is a comparative study of multi-point approaches. A new metric of planarity is adopted to analyse the spatial distribution of energy in the target zone, and the well-established metrics of acoustic contrast and control effort are also used. Simulations and experimental results demonstrate the advantages and disadvantages of the approaches. Energy cancellation produces good acoustic contrast but allows very little control over the target sound field; synthesis-derived approaches precisely control the target sound field but produce less contrast. Motivated by the limitations of the existing optimization methods, the central contribution of this thesis is a proposed optimization cost function ‘planarity control’, which maximizes the acoustic contrast between the zones while controlling sound field planarity by projecting the target zone energy into a spatial domain. Planarity control is shown to achieve good contrast and high target zone planarity over a large frequency range. The method also has potential for reproducing stereophonic material in the context of sound zones. The remaining contributions consider two further practical concerns. First, judicious choice of the regularization parameter is shown to have a significant effect on the contrast, effort and robustness. Second, attention is given to the problem of optimally positioning the loudspeakers via a numerical framework and objective function. The simulation and experimental results presented in this thesis represent a significant addition to the literature and will influence the future choices of control methods, regularization and loudspeaker placement for personal audio. Future systems may incorporate 3D rendering and listener tracking.

Gli stili APA, Harvard, Vancouver, ISO e altri

Francombe, J. "Perceptual evaluation of audio-on-audio interference in a personal sound zone system". Thesis, University of Surrey, 2014. http://epubs.surrey.ac.uk/806072/.

Testo completo

Abstract (sommario):

There are many situations in which two or more audio programmes may be replayed in the same acoustic space. Such situations can either occur naturally or be deliberately engendered, for example in a system designed to produce personal sound zones. In order to improve the experience of a listener in the presence of an audio interferer, it is desirable to model the relationship between listener experience and physical parameters of the situation. Such a model could be used to optimise audio-on-audio interference situations in a perceptually relevant manner. The first stage of this research involved determination of attributes of the perceptual experience of a listener in an audio-on-audio interference situation. Attributes used in similar research areas were reviewed and an elicitation experiment–combining aspects of individual and group direct elicitation methods preceding a rating experiment–was performed. 'Distraction' was found to be the most relevant attribute for describing the experience of a listener in an audio-on-audio interference situation. The next stage of the research consisted of determining relevant physical parameters and producing a model of distraction. An experiment was performed in which distraction ratings were collected for one hundred randomly created audio-on-audio interference stimuli. Physical parameters were determined following a verbal protocol analysis performed on written descriptions of reasons for the perceived distraction; the resultant categories were used to suggest appropriate features. A linear regression procedure was used to determine the relationship between the features and distraction scores. The selected features were: overall loudness; loudness-based target-to-interferer ratio (TIR); perceptual evaluation of audio source separation (PEASS) toolbox interference-related perceptual score (IPS); level range in the high frequency bands of the interferer; and percentage of temporal windows with low TIR. The resultant model was found to fit well to the training and validation data sets with a root-mean-square error (RMSE) of approximately 10%.

Gli stili APA, Harvard, Vancouver, ISO e altri

Roussel, Georges. "Contributions à la mise au point de méthodes adaptatives de reproduction de champs sonores multi-zone pour les auditeurs en mouvement : Sound zones pour auditeurs en mouvement". Thesis, Le Mans, 2019. http://www.theses.fr/2019LEMA1018/document.

Testo completo

Abstract (sommario):

Le nombre croissant d'appareils de diffusion de contenus audio pose le problème de partager le même espace physique sans partager lemême espace sonore. Les Sound Zones rendent possible la reproduction de programmes audio indépendants et spatialement séparés, àpartir d'un ensemble de haut-parleurs et de méthodes de reproduction de champs sonores. Le problème est alors décomposé en deuxzones : la Bright zone, où le contenu doit être reproduit et la Dark zone, où il doit être annulé. De nombreuses méthodes existent pourrésoudre ce problème, mais la plupart ne traite que le cas d'auditeurs en position statique. Elles s'appuient sur la résolution directe desméthodes d'optimisation adaptative, telle que la méthode de Pressure Matching (PM). Or, pour des utilisateurs en mouvement, cesméthodes ont un coût de calcul trop élevé, rendant impossible leur application à un problème dynamique. Le but de cette thèse est dedévelopper une solution présentant une complexité compatible avec un contrôle dynamique des Sound Zones, tout en conservant lesperformances des méthodes conventionnelles. Sous l'hypothèse que les déplacements sont lents, une résolution itérative du problème PMest proposée et évaluée. Les algorithmes LMS, NLMS et APA sont comparés sur la base de simulations en champ libre. La méthode LMSs'avère la plus avantageuse en termes de complexité, mais elle souffre d'une erreur de reproduction. Un effet mémoire limitant la réactivitédes algorithmes est aussi mis en évidence. Il est corrigé en implémentant une variante introduisant un facteur d'oubli (Variable LeakyLMS ou VLLMS)
The growing number of audio devices raises the problem of sharing the same physical space without sharing the same sound space. SoundZones make it possible to play independent and spatially separated audio programs by loudspeaker array in combination with sound fieldreproduction methods. The problem is then split into two zones: the Bright zone, where the audio content must be reproduced and theDark zone, where it must be cancelled. There are many methods available to solve this problem, but most only deal with auditors in astatic position. They are based on the direct resolution of adaptive optimization methods, such as the Pressure Matching (PM) method.However, for moving users, these methods have a too high computation cost, making it impossible to apply them to a dynamic problem.The aim of this thesis is to develop a solution offering a level of complexity compatible with a dynamic control of Sound Zones, whilemaintening the performance of conventional methods. Under the assumption that displacements are slow, an iterative resolution of the PMproblem is proposed and assessed. The LMS, NLMS and APA algorithms are compared on the basis of free field simulations. The LMSmethod is the most advantageous in terms of complexity, but it suffers from a reproduction error. A memory effect limiting the reactivityof the algorithms is also highlighted. It is corrected by implementing a leaky variant (Variable Leaky LMS or VLLMS) introducing aforgetting factor

Gli stili APA, Harvard, Vancouver, ISO e altri

Marshall, Kingsley. "The Gulf War aesthetic? : certain tendencies in image, sound and the construction of space in 'Green Zone' and 'The Hurt Locker'". Thesis, University of East Anglia, 2018. https://ueaeprints.uea.ac.uk/67801/.

Testo completo

Abstract (sommario):

This thesis argues that the perception of realism and ‘truth’ within narrative feature films set within the Gulf War (1990-1991) and Iraq War (2003-2011) is bound up in other transmedia representations of these conflicts. I identify and define what I describe as the Gulf War Aesthetic, and argue that an understanding of the ‘real life’ of the war film genre through its telling in news reportage, documentary and combatant-originated footage serves as a gateway through which the genre of fictional feature films representing the conflicts and their aftermath is constructed. I argue that the complexity of the Iraq War, coupled with technological shifts in the acquisition and distribution of video and audio through online video-sharing platforms including YouTube, further advanced the Gulf War Aesthetic. I identify The Hurt Locker (Bigelow, 2009) and Green Zone (Greengrass, 2010) as helpful case studies to evidence these changes, and subject both to detailed analysis. I draw an alignment of the creative practice of film practitioners involved in the case studies with a detailed, intrasoundtrack analysis of the scenes they discuss. In The Hurt Locker, I demonstrate that this presents itself in an unusual unification of film sound with image, where sound recording and design, in addition to the deployment of music, operate to communicate the components of a narrative specific to the story of bomb disposal. I contrast this with Green Zone, where I argue that the Gulf War Aesthetic is limited by the deployment of more conventional characteristics of the war film genre. This analysis reveals that transmedia contexts of production are operating and how new aesthetics are being reified and codified in cinema. I evaluate the subsequent impact of this outside the specific genre of the war film, particularly in terms of a shift in the way in which spectacle is presented.

Gli stili APA, Harvard, Vancouver, ISO e altri

PEPE, GIOVANNI. "Deep Optimization of Discrete Time Filters for Listening Experience Personalization". Doctoral thesis, Università Politecnica delle Marche, 2022. http://hdl.handle.net/11566/293461.

Testo completo

Abstract (sommario):

Questa tesi descrive lo studio di tecniche di Machine Learning per l'ottimizzazione di filtri digitali per l'Equalizzazione Audio Multipunto e la Personal Sound Zones (PSZ) all'interno di uno scenario automotive. L'Equalizzazione Audio Multipunto è un argomento che mira a migliorare la qualità audio in un sistema di altoparlanti utilizzando filtri digitali. La Personal Sound Zones è un task che permette la riproduzione dei suoni in diverse regioni contenute in un ambiente d'ascolto dove sono presenti più ascoltatori. In questa tesi, è stato riportato uno stato dell'arte aggiornato sulla progettazione di filtri digitali, tecniche di Equalizzazione Audio Multipunto e di PSZ. In questa dissertazione, le tecniche di ottimizzazione basate sulle reti neurali, denominate Deep Optimization, hanno dimostrato di essere le più performanti tra i metodi proposti. L'approccio sfrutta le reti neurali per ottimizzare iterativamente i parametri dei filtri utilizzando la feed-forward e la backpropagation e aggiornando i pesi con un ottimizzatore. È stata analizzata una nuova architettura di ottimizzazione profonda, chiamata Bias Network (BiasNet), la quale utilizza i termini di bias come input e aggiorna i suoi pesi per ottenere i filtri ottimali. Gli esperimenti per l'equalizzazione audio con filtri FIR sono stati eseguiti all'interno di vari scenari automotive, ottenendo risultati migliori rispetto alle tecniche presenti nello stato dell'arte. Altri esperimenti sono stati eseguiti con i filtri Parametrici IIR, ottenendo prestazioni migliori rispetto alle tecniche di progettazione dei filtri IIR e FIR. Infine, analizzando il costo computazionale, i filtri IIR Parametrici richiedono meno operazioni e meno memoria. Infine, sono stati condotti esperimenti per progettare filtri FIR e IIR parametrici per PSZ, introducendo termini di regolarizzazione e penalità per eliminare gli artefatti generati dai filtri FIR. I risultati sono molto promettenti, ottenendo un alto contrasto acustico mantenendo una qualità del suono alta. I filtri IIR hanno ottenuto dei risultati comparabili con un costo computazionale inferiore rispetto ai filtri FIR.
This thesis describes the study of Machine Learning techniques for the optimization of digital filters for Multipoint Audio Equalization and Personal Sound Zones (PSZ) in a car scenario. Multipoint Audio Equalization is a topic that aims to improve the audio quality in a loudspeaker system using digital filters. The Personal Sound Zones is a task that allows the reproduction of different sounds in several regions contained within a listening environment where multiple listeners are present. An up-to-date state of the art on digital filter design, Multipoint Audio Equalization and PSZ techniques have been reported in this thesis. Neural network-based optimization techniques, referred to as Deep Optimization, proved to be the best performing and the most analyzed methods within the proposed approaches. The technique exploits neural networks to iteratively optimize the filter parameters using the feed-forward and backpropagation, updating the weights with an optimizer. A new Deep Optimization architecture has been analyzed, called Bias Network (BiasNet), which uses the bias terms as input and updates its weights to obtain the optimal filters. Experiments for Multipoint Audio Equalization with FIR filters were performed within various automotive scenarios, achieving better results than the state-of-the-art techniques. Other experiments were carried out with Parametric IIR filters, achieving better performance than baseline IIR and FIR filter design methods. Furthermore, analyzing the computational cost, Parametric IIR filters require less operations and memory. Finally, experiments were conducted to design FIR and Parametric IIR filters for PSZ, introducing regularization and penalty terms to eliminate artefacts generated by FIR filters. The results are very promising, achieving a high acoustic contrast keeping high sound quality. IIR filters achieved comparable results with a lower computational cost than FIR filters.

Gli stili APA, Harvard, Vancouver, ISO e altri

Pages, Guilhem. "Zones d’écoute personnalisées mobiles par approches adaptatives". Electronic Thesis or Diss., Le Mans, 2024. http://www.theses.fr/2024LEMA1012.

Testo completo

Abstract (sommario):

La thèse aborde la création de sound zones (zones d'écoute personnalisées) mobiles par des approches adaptatives. Les méthodes en usage pour la création de sound zones visent à résoudre conjointement la reproduction sonore dans une zone et la minimisation de l'énergie du signal reproduit dans l'autre zone, à partir d'un réseau de haut-parleurs. La thèse se divise en deux parties : l'estimation des réponses impulsionnelles et les sound zones mobiles. L'objectif de cette thèse est de créer deux zones de l'espace dont le champ acoustique est contrôlé, ces zones pouvant bouger dans l'espace au cours du temps. Dans la première partie, l'estimation des réponses impulsionnelles du système est détaillée, prérequis nécessaire pour les algorithmes de sound zones. A partir des méthodes adaptatives existantes pour l'estimation de systèmes multi-entrées multi-sorties variant dans le temps, une nouvelle méthode appliquée à l'acoustique et MISO est présentée. Cette méthode, appelée MISO-Autostep, permet d'estimer les réponses impulsionnelles au cours du temps sans avoir de paramètres à ajuster finement. Dans la seconde partie, l'algorithme de \sound zones BACC-PM est réécrit sous forme récursive. Cette capacité à mettre à jour les coefficients des filtres au cours du temps ouvre la voie à s'adapter à des changements temporels dans la géométrie du système. Enfin, des résultats préliminaires sont présentés avec l'utilisation conjointe des deux algorithmes adaptatifs dans le cas d'une modification brusque de la géométrie du système
The thesis deals with the creation of mobile sound zones using adaptive approaches. The methods in use for the creation of sound zones aim to jointly resolve the sound reproduction in one zone and the minimisation of the energy of the signal reproduced in the other zone, from an array of loudspeakers. The thesis is divided into two parts: the estimation of impulse responses and moving sound zones. The aim of this thesis is to create two zones in space with a controlled sound field, which can move in space over time. In the first part, the estimation of the system's impulse responses is detailed, a necessary prerequisite for sound zone algorithms. Based on existing adaptive methods for estimating time-varying multi-input, multi-output systems, a new method applied to acoustics and MISO is presented. This method, called MISO-Autostep, makes it possible to estimate impulse responses over time without having to fine-tune any parameters. In the second part, the BACC-PM sound zone algorithm is rewritten in recursive form. This ability to update the filter coefficients over time opens up the possibility of adapting to temporal changes in the system geometry. Finally, preliminary results are presented with the joint use of the two adaptive algorithms in the case of an abrupt change in the system geometry

Gli stili APA, Harvard, Vancouver, ISO e altri

Kalužová, Adéla. "Vliv terapeutického ultrazvukového pole a metalických nanočástic na nádorové buňky". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-220854.

Testo completo

Abstract (sommario):

This thesis focuses on the research of an effect of ultrasound and nanoparticles on cancer cells. In the literature search there the applications of ultrasound field in the interaction with aplication of metallic nanoparticles to viability of cancer cells are described, on the basis of in vitro experiments‘ performance. The purpose of metallic nanoparticles‘ application should be a possible reinforcing of its antitumor effect thanks to the presence of ultrasound field. In next part of the literature search there are included the technical performance of devices, their indications and contraindications, parameters of ultrasound fields and application of metallic nanoparticles. The metallic nanoparticles have been becoming a part of the human’s life more and more, that is why it’s necessary to deal with these miniature particles at a higher level. The aim of this thesis is to suggest the ways of resolution based on the principle of sounding of cells with the ultrasound field of suitable parameters and in combination with the application of metallic nanoparticles with a successive performance of the cell viability tests. The viability was determinated by the MTT assay test. Another part of this work is the measurement of parameters of this zone by means of a submersible needle hydrophone, for a better understanding of the ultrasonic zone. In the final part of this work there is necessary the statistical evaluation of the measured data of the experiments carried out and the discussion of the results obtained.

Gli stili APA, Harvard, Vancouver, ISO e altri

Rutger, Kastby Claes. "Active control for adaptive sound zones in passenger train compartments". Thesis, KTH, Farkost och flyg, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-143502.

Testo completo

Abstract (sommario):

The acoustics in train compartments is an important part of the comfort when travelling. To improve the acoustics, active noise control (ANC) can be used to create local quiet zones at the passenger ear position. In this thesis the fundamental ANC theory is explained and the possibilities and limitations with the technique are identified. An ANC system which uses the virtual microphone technique is implemented and quiet zones are realized at a chair in a train compartment studio. The performance of the ANC system is evaluated with a Styrofoam head model with built in microphones that is used to produce contour plots of the quiet zone shape and attenuation level. The results show that the 10 dB quiet zone is relatively large covering more than a square decimeter in low frequencies and decreases with frequency. Head movements effects are also evaluated and the results show that the system is very sensitive to head movements, especially in higher frequencies. In order to find an optimal positioning of the system components, several experiments have been made. From these it is concluded that varying noise incidence is problematic to some extent. Ways of handling the problems are presented and if the problems were properly dealt with ANC could be an effective way of reducing noise in passenger train compartments.

Gli stili APA, Harvard, Vancouver, ISO e altri

Rusina, Michal. "Stanovení vlastností ultrazvukových sond". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221368.

Testo completo

Abstract (sommario):

This master thesis deals with the measurement properties of ultrasound probes. Ultrasound probes and their parameters significantly affect the quality of the final image. Values of pa-rameters of the probes may change due to their use, because probes may be damaged and the final image may no longer be correct. For these reasons the measurements of parameters of probes are very important. In this master thesis there are described and implemented the possibility of measuring the spatial resolution, focal zone, the sensitivity of the probe and measuring the length of the dead zone. Two ultrasonic phantoms were used for measuring. In the practical part there was created the program called Mereni_parametru, which allows to determine the value of four parameters from captured images of the phantom. Further, there are listed and described measured values for five ultrasonic probes. Results for two of these probes are then compared with the parameters given by the manufacturers.

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Libri sul tema "Sound zone"

Canning, Douglas J. Coastal erosion management studies in Puget Sound, Washington: Executive summary. Olympia, Wash: Water and Shorelands Resources Program, Washington Dept. of Ecology, 1995.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Keith, MacDonald, Washington (State). Shorelands & Coastal Zone Management Program. e Coastal Erosion Management Strategy (Wash.), a cura di. Shoreline armoring effects on physical coastal processes in Puget Sound, Washington. Olympia, Wash: Shorelands and Coastal Zone Management Program, Washington Dept. of Ecology, 1994.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Jack, Cox. Engineering and geotechnical techniques for shoreline erosion management in Puget Sound. Olympia, Wash: Shorelands and Coastal Zone Management Program, Washington Dept. of Ecology, 1994.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

MacDonald, Keith. Management options for unstable bluffs in Puget Sound, Washington. Olympia, Wash: Shorelands and Coastal Zone Management Program, Washington Dept. of Ecology, 1994.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Lynn, Brian. Nearshore habitat loss in Puget Sound: Recommendations for improved management. [Olympia?, Wash.]: Puget Sound/Georgia Basin International Task Force, [1998], 1998.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Clancy, Margaret. Management measures for protecting and restoring the Puget Sound Nearshore: Prepared in support of the Puget Sound Nearshore Ecosystem Restoration Project. Olympia, Wash: Washington Dept. of Fish and Wildlife, 2009.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Johannessen, Jim. Beaches and bluffs of Puget Sound. [Seattle, Wash: Seattle District, U.S. Army Corps of Engineers, 2007.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Johannessen, Jim. Beaches and bluffs of Puget Sound. [Seattle, Wash: Seattle District, U.S. Army Corps of Engineers, 2007.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Terich, Thomas. Living with the shore of Puget Sound and the Georgia Strait. Durham: Duke University Press, 1987.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Menashe, Elliott. Vegetation management: A guide for Puget Sound bluff property owners. Olympia, Wash: The Program, 1993.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Capitoli di libri sul tema "Sound zone"

Papanicolaou, P., e F. Raichlen. "Wave and Bubble Characteristics in the Surf Zone". In Sea Surface Sound, 97–109. Dordrecht: Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-3017-9_8.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Ahlhorn, Frank. "Sound Options – Multifunctional Coastal Protection Zones". In Long-term Perspective in Coastal Zone Development, 123–64. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-01774-2_5.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Buckingham, Michael J., e Chi-fang Chen. "Acoustic Ambient Noise in the Arctic Ocean Below the Marginal Ice Zone". In Sea Surface Sound, 583–98. Dordrecht: Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-3017-9_42.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Rottier, Philip. "Wave Induced Noise Generation in the Marginal Ice Zone". In Natural Physical Sources of Underwater Sound, 611–24. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1626-8_45.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Johansen, Stine S., Peter Axel Nielsen, Kashmiri Stec e Jesper Kjeldskov. "Using Colour and Brightness for Sound Zone Feedback". In Human-Computer Interaction – INTERACT 2023, 247–72. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-42280-5_15.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Akshay, S., Paul Gastin e Karthik R. Prakash. "Fast Zone-Based Algorithms for Reachability in Pushdown Timed Automata". In Computer Aided Verification, 619–42. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-81685-8_30.

Testo completo

Abstract (sommario):

AbstractGiven the versatility of timed automata a huge body of work has evolved that considers extensions of timed automata. One extension that has received a lot of interest is timed automata with a, possibly unbounded, stack, also called pushdown timed automata (PDTA). While different algorithms have been given for reachability in different variants of this model, most of these results are purely theoretical and do not give rise to efficient implementations. One main reason for this is that none of these algorithms (and the implementations that exist) use the so-called zone-based abstraction, but rely either on the region-abstraction or other approaches, which are significantly harder to implement.In this paper, we show that a naive extension, using simulations, of the zone based reachability algorithm for the control state reachability problem of timed automata is not sound in the presence of a stack. To understand this better we give an inductive rule based view of the zone reachability algorithm for timed automata. This alternate view allows us to analyze and adapt the rules to also work for pushdown timed automata. We obtain the first zone-based algorithm for PDTA which is terminating, sound and complete. We implement our algorithm in the tool TChecker and perform experiments to show its efficacy, thus leading the way for more practical approaches to the verification of timed pushdown systems.

Gli stili APA, Harvard, Vancouver, ISO e altri

Trenerry, L. J., A. McMinn e K. G. Ryan. "In situ oxygen microelectrode measurements of bottom-ice algal production in McMurdo Sound, Antarctica". In Ecological Studies in the Antarctic Sea Ice Zone, 185–93. Berlin, Heidelberg: Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/978-3-642-59419-9_24.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Nardini, Luisa. "Reuniting Fragments and Reconsidering the Scribal History of the Beneventan Zone". In The Materiality of Sound in Chant Manuscripts in the West, 175–97. Turnhout: Brepols Publishers, 2023. http://dx.doi.org/10.1484/m.musam-eb.5.134480.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Krek, Alexander V., Elena V. Krek e Viktor A. Krechik. "The Circulation and Mixing Zone in the Antarctic Sound in February 2020". In Advances in Polar Ecology, 83–99. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-78927-5_6.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Jacobsen, Steven D., e Joseph R. Smyth. "Effect of Water on the Sound Velocities of Ringwoodite in the Transition Zone". In Earth's Deep Water Cycle, 131–45. Washington, D. C.: American Geophysical Union, 2013. http://dx.doi.org/10.1029/168gm10.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Atti di convegni sul tema "Sound zone"

ANGUS, JAS. "THE REFLECTION FULL ZONE". In Reproduced Sound 1996. Institute of Acoustics, 2024. http://dx.doi.org/10.25144/19931.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Jacobsen, Rune Møberg, Stine S. Johansen, Niels van Berkel, Mikael B. Skov e Jesper Kjeldskov. "In the Zone! — Controlling and Visualising Sound Zones". In CHI '22: CHI Conference on Human Factors in Computing Systems. New York, NY, USA: ACM, 2022. http://dx.doi.org/10.1145/3491101.3519898.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

GREGORY, SJ. "ROCK MUSIC AT MAINE ROAD, MANCHESTER - A NOISE TOLERANT ZONE?" In Reproduced Sound 1992. Institute of Acoustics, 2024. http://dx.doi.org/10.25144/20881.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Brunnström, Jesper, Toon van Waterschoot e Marc Moonen. "Sound Zone Control for Arbitrary Sound Field Reproduction Methods". In 2023 31st European Signal Processing Conference (EUSIPCO). IEEE, 2023. http://dx.doi.org/10.23919/eusipco58844.2023.10289995.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

MAPP, P., P. BARNETT e J. OLIVER. "THE DESIGN IMPLEMENTATION AND COMMISSIONING OF A COMPUTER-CONTROLLED MULTI-ZONE SOUND SYSTEM FOR THE ROYAL HONG KONG JOCKEY CLUB". In Reproduced Sound 1987. Institute of Acoustics, 2024. http://dx.doi.org/10.25144/22026.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Zhou, M., M. B. Møller, C. S. Pedersen, N. E. M. D. Koeijer e J. Østergaard. "Robust Sound Zone Filters for Synchronization Errors". In 10th Convention of the European Acoustics Association Forum Acusticum 2023. Turin, Italy: European Acoustics Association, 2024. http://dx.doi.org/10.61782/fa.2023.0829.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Qipeng, Feng, Yang Feiran e Yang Jun. "Compressed sensing based multi-zone sound field reproduction". In 2016 IEEE 13th International Conference on Signal Processing (ICSP). IEEE, 2016. http://dx.doi.org/10.1109/icsp.2016.7877871.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Johansen, Stine S., Rune Møberg Jacobsen, Mikael B. Skov e Jesper Kjeldskov. "Contextual and Informational Aspects of Sound Zone Visualisations". In AM '22: AudioMostly 2022. New York, NY, USA: ACM, 2022. http://dx.doi.org/10.1145/3561212.3561240.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Yamaguchi, Ryuji, Shinji Sugihara e Masahito Hirakawa. "Sound Zone Control in an Interactive Table System Environment". In 2011 IEEE International Symposium on Multimedia (ISM). IEEE, 2011. http://dx.doi.org/10.1109/ism.2011.40.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Betlehem, Terence, e Paul D. Teal. "A constrained optimization approach for multi-zone surround sound". In ICASSP 2011 - 2011 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP). IEEE, 2011. http://dx.doi.org/10.1109/icassp.2011.5946434.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Rapporti di organizzazioni sul tema "Sound zone"

Rutledge, Annamarie, e Leslie (Leslie Alyson) Brandt. Puget Sound Region. Houghton, MI: USDA Northern Forests Climate, giugno 2023. http://dx.doi.org/10.32747/2023.8054016.ch.

Testo completo

Abstract (sommario):

As the climate changes over the 21st century, the Puget Sound region's urban forest will be impacted by changing temperatures and precipitation regimes, leading to implications for the people who depend on its ecosystem services. This report summarizes climate change projections for the Puget Sound region and provides an assessment of tree species vulnerability in the region. We used projected shifts in plant hardiness and heat zones to understand how tree species of interest are projected to tolerate future conditions. We also assessed the adaptability of planted trees to stressors such as drought, flooding, wind damage, and air pollution, as well as environmental conditions such as shade, soils, and restricted rooting using "modification factors"--an adaptability scoring system for planted environments. The region has been warming at a rate of about 0.4°F per decade since 1960, and the average temperature is projected to increase by 5.0°F to 8.6°F by the end of the century compared with the 1971-2000 historical average. Precipitation in the region has been increasing by over 0.5 inches per decade since 1960 and is projected to increase by 2.1 to 3.2 inches by the end of the century compared with the 1971-2000 historical average. By the end of the century, the Puget Sound region is projected to shift from hardiness zones 8-9 to zone 9 completely, and from heat zone 2 to heat zone 3 (RCP4.5) or 6 (RCP8.5), depending on the climate change scenario. Of the evaluated tree species, 27% were rated as having high adaptability, 59% were rated as having medium adaptability, and 14% were rated as having low adaptability. Given that the hardiness zone range is projected to remain within the historical (1980-2009) range, we considered both heat zones alone as well as heat and hardiness zones. Considering heat zones only, most of the assessed tree species fell into the low-moderate vulnerability category (57%), followed by low vulnerability (26%) and moderate vulnerability (17%) under both low and high climate change scenarios. The vulnerability ratings remain the same between low and high climate change scenarios because all assessed tree species are considered suitable under both sets (low and high) of heat zone projections through the end of the century. Considering both heat and hardiness zones, most of the assessed tree species fell into the moderate-high vulnerability category (34%), followed by low-moderate (25%), moderate (18%), low (14%), and high (9%). The vulnerability ratings are the same between low and high climate change scenarios because the projected hardiness zone is the same under both scenarios through the end of the century. The vulnerability of individual species is not the only factor to consider when making urban forestry decisions, and this assessment also contains species diversity and human health as additional factors. These projected changes in climate and their associated impacts and vulnerabilities will have important implications for urban forest management, including the planting and maintenance of street and park trees, equity and environmental justice efforts, and long-term planning from partnerships to green infrastructure.

Gli stili APA, Harvard, Vancouver, ISO e altri

Unknown, Author. L51602 Criteria for Hot Tap Welding Further Studies. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), maggio 1989. http://dx.doi.org/10.55274/r0010102.

Testo completo

Abstract (sommario):

In the gas transmission industry there is a frequent need for modification of existing pipework. Modifications are made primarily by welding on additional pipes and branch connections to existing pipelines. The associated costs of shutting down a pipeline creates a situation whereby it becomes economically feasible to weld onto pipelines containing flowing, pressurized products. The risk of burn through and in particular, the susceptibility to cracking are greatly increased by the rapid cooling rates associated with the high heat sink effect of the flowing gas and in turn can result in excessive hardening of the heat affected zone in ferritic steels. Edison Welding Institute developed new criteria for safe hot tap welding procedures on all ferritic steels. Their approach is based on correlating field measurements of the ability of the pipe to conduct heat (i.e., its heat-sink capacity) to the cooling rate of the weld. Laboratory welding trials with simulated branch and sleeve connections on live pipelines containing natural gas were used to validate the new criteria. The results indicate that structurally sound hot tap repairs can be made with a high level of confidence.

Gli stili APA, Harvard, Vancouver, ISO e altri

Brasseur, Sophie, Geert Aarts e Jessica Schop. Measurement of effects of pile driving in the Borssele wind farm zone on the seals in the Dutch Delta area- version II : Changes in dive behaviour, haul-out and stranding of harbour and grey seals, including sound modelling. Den Helder: Wageningen Marine Research, 2022. http://dx.doi.org/10.18174/578120.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Paxton, Barton, e Chance Hines. Black rail inventory at Cape Lookout and Cape Hatteras national seashores. National Park Service, 2024. http://dx.doi.org/10.36967/2304485.

Testo completo

Abstract (sommario):

The black rail (Laterallus jamaicensis) is the most secretive of the secretive marsh birds and one of the least understood species in North America. On the east coast, eastern black rails historically bred in tidal and freshwater marshes along the Atlantic coast from Massachusetts, south to Florida. Within the mid-Atlantic region suitable black rail habitat is concentrated in the high marsh along the upper elevational zone of salt marshes. This zone is dominated by salt meadow hay (Spartina patens), saltgrass (Distichlis spicata), and is often interspersed with shrubs such as marsh elder (Iva frutescens) or saltbush (Baccharis hamilifolia). North Carolina has been a stronghold for eastern black rails within the mid-Atlantic region, with the marsh complexes associated with the lower Pamlico sound supporting one of largest concentrations and highest densities of eastern black rails throughout their range. However, even within these marshes, eastern black rail populations have experienced declines marked by reductions in occupied sites and decline in numbers within historic strongholds. Evidenced by increasing confinement to the highest portions of the high marsh in recent years, sea-level rise and increased rates of high marsh inundation are likely a major contributing factor to declines. With the population of eastern black rails declining over 75% in the last 10-20 years, the U. S. Fish and Wildlife Service formally listed the eastern black rail as threatened under the endangered species act on 9 November 2020 (USFWS 2020). To fulfill the need for information to guide management decisions on projects at Cape Lookout and Cape Hatteras National Seashores and to aide in (potential?) future designations of critical habitat, we conducted widespread, systematic surveys for black rails and other secretive marsh birds within the parks during the breeding seasons of 2022 and 2023. A total of 1,222 surveys were conducted at 431 points over the course of 2 years. In addition to recording detections of all focal species, we recorded detections of 6 eastern black rails on North Core Banks where they were not previously known to occur. The population of black rails occupying the high marsh habitat on North Core Banks could account for 5-10% of the North Carolina black rail population and increase the known sites occupied within the state.

Gli stili APA, Harvard, Vancouver, ISO e altri

Abrahamson, Norman, Nicolas Kuehn, Zeynep Gulerce, Nicholas Gregor, Yousef Bozorgnia, Grace Parker, Jonathan Stewart et al. Update of the BC Hydro Subduction Ground-Motion Model using the NGA- Subduction Dataset. Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, giugno 2018. http://dx.doi.org/10.55461/oycd7434.

Testo completo

Abstract (sommario):

An update to the BCHydro ground-motion model for subduction earthquakes has been developed using the 2018 PEER NGA-SUB dataset. The selected subset includes over 70,000 recordings from 1880 earthquakes. The update modifies the BCHydro model to include regional terms for the VS30 scaling, large distance (linear R) scaling, and constant terms, which is consistent with the regionalization approach used in the NGA-W2 ground-motion models. A total of six regions were considered: Cascadia, Central America, Japan, New Zealand, South America, and Taiwan. Region- independent terms are used for the small-magnitude scaling, geometrical spreading, depth to top of rupture (ZTOR ) scaling, and slab/interface scaling. The break in the magnitude scaling at large magnitudes for slab earthquakes is based on thickness of the slab and is subduction-zone dependent. The magnitude scaling for large magnitudes is constrained based on finite-fault simulations as given in the 2016 BCHydro model. Nonlinear site response is also constrained to be the same as the 2016 BCHydro model. The sparse ground-motion data from Cascadia show a factor of 2–3 lower ground motions than for other regions. Without a sound physical basis for this large reduction, the Cascadia model is adjusted to be consistent with the average from all regions for the center range of the data: M = 6.5, R = 100 km, VS30 = 400 m/sec. Epistemic uncertainty is included using the scaled backbone approach, with high and low models based on the range of average ground motions for the different regions. For the Cascadia region, the ground-motion model is considered applicable to distance up to 1000 km, magnitudes of 5.0 to 9.5, and periods from 0 to 10 sec. The intended use of this update is to provide an improved ground-motion model for consideration for use in the development of updated U.S. national hazard maps. This update ground-motion model will be superseded by the NGA-SUB ground-motion model when they are completed.

Gli stili APA, Harvard, Vancouver, ISO e altri

Blais-Stevens, A., A. Castagner, A. Grenier e K D Brewer. Preliminary results from a subbottom profiling survey of Seton Lake, British Columbia. Natural Resources Canada/CMSS/Information Management, 2023. http://dx.doi.org/10.4095/332277.

Testo completo

Abstract (sommario):

Seton Lake is a freshwater fiord located in southwestern British Columbia, roughly 4 km west of Lillooet and 250 km north-northeast of Vancouver. Located in the Coast Mountains, it is an alpine lake about 22-km long and roughly 1-1.5 km wide. It is separated from nearby Anderson Lake, located to the west, by a large pre-historic rock avalanche deposit at Seton Portage. The lake stands at about 243 m above sea level and is up to about 150 m deep (BC gov., 1953). Water level is controlled by a hydroelectric dam (i.e., Seton dam) located at the eastern end of the lake. Here, the lake drains east into Seton Canal, a 5 km diversion of the flow of the Seton River, which begins at the Seton dam. The Seton Canal pushes water to the Seton Powerhouse, a hydroelectric generating station at the Fraser River, just south of the community of Sekw'el'was and confluence of the Seton River, which drains into the Fraser River at Lillooet. Seton Portage, Shalatlh, South Shalatlh, Tsal'alh (Shalath), Sekw'el'was (Cayoosh Creek), and T'it'q'et (Lillooet) are communities that surround the lake. Surrounded by mountainous terrain, the lake is flanked at mid-slope by glacial and colluvial sediments deposited during the last glacial and deglacial periods (Clague, 1989; Jakob, 2018). The bedrock consists mainly of mafic to ultramafic volcanic rocks with minor carbonate and argillite from the Carboniferous to Middle Jurassic periods (Journeay and Monger, 1994). As part of the Public Safety Geoscience Program at the Geological Survey of Canada (Natural Resources Canada), our goal is to provide baseline geoscience information to nearby communities, stakeholders and decision-makers. Our objective was to see what kind of sediments were deposited and specifically if we could identify underwater landslide deposits. Thus, we surveyed the lake using a Pinger SBP sub bottom profiler made by Knudsen Engineering Ltd., with dual 3.5 / 200 kHz transducers mounted to a small boat (see photo). This instrument transmits sound energy down through the water column that reflects off the lake bottom surface and underlying sediment layers. At the lake surface, the reflected sound energy is received by the profiler, recorded on a laptop computer, and integrated with GPS data. These data are processed to generate a two-dimensional image (or profile) showing the character of the lake bottom and underlying sediments along the route that the boat passed over. Our survey in 2022 recorded 98 profiles along Seton Lake. The red transect lines show the locations of the 20 profiles displayed on the poster. The types of sediments observed are mostly fine-grained glaciolacustrine sediments that are horizontally bedded with a subtle transition between glaciolacustrine to lacustrine (e.g., profiles A-A'; C-C'; F-F'; S-S'). Profile S-S' displays this transition zone. The glaciolacustrine sediments probably were deposited as the Cordilleran Ice Sheet retreated from the local area (~13,000-11,000 years ago; Clague, 2017) and the lacustrine sediments, after the ice receded to present-day conditions. Some of the parallel reflections are interrupted, suggesting abrupt sedimentation by deposits that are not horizontally bedded; these are interpreted as landslide deposits (see pink or blue deposits on profiles). The deposits that show disturbance in the sedimentation found within the horizontal beds are thought to be older landslides (e.g., blue arrows/deposits in profiles C-C'; E-E'; F-F'; G-G'; I-I'; J-J'; K-K'; N-N'; P-P'; Q-Q'; R-R'; T-T'; U-U'), but the ones that are found on top of the horizontally laminated sediments (red arrows/pink deposits), and close to the lake wall, are interpreted to be younger (e.g., profiles B-B'; C-C'; H-H'; K-K'; M-M'; O-O'; P-P'; Q-Q'). At the fan delta just west of Seton dam, where there was no acoustic signal penetration, it is interpreted that the delta failed and brought down coarser deposits at the bottom of the lake (e.g., profiles H-H'; M-M'; and perhaps K-K'). However, these could be glacial deposits, bedrock, or other coarser deposits. Some of the deposits that reflect poor penetration of the acoustic signal, below the glaciolacustrine sediments, could represent glacial deposits, old landslide deposits, or perhaps the presence of gas (orange arrows; e.g, B-B'; D-D'; J-J'; O-O', T-T'). The preliminary results from sub bottom profiling reveal that there are underwater landslides deposits of widely varying ages buried in the bottom of the lake. However, the exact timing of these is not known. Hence our preliminary survey gives an overview of the distribution of landslides where there seems to be a larger number of landslides recorded in the narrower eastern portion of the lake.

Gli stili APA, Harvard, Vancouver, ISO e altri

Okulitch, A. V. Déformation des Zones de Plissement de Central Ellesmere et de Jones Sound du Dévonien Tardif au Carbonifère [Chapitre 12: Phases de Déformation et Métamorphisme et Plutonisme Associés au Silurien et Carbonifère Précoce dans l'Achipel Arctique]. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1991. http://dx.doi.org/10.4095/133988.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

VIBRO-ACOUSTICAL PERFORMANCE OF A STEEL BEAM OF GROOVE PROFILE: FIELD TEST AND NUMERICAL ANALYSIS. The Hong Kong Institute of Steel Construction, agosto 2022. http://dx.doi.org/10.18057/icass2020.p.063.

Testo completo

Abstract (sommario):

To meet the development needs of rail transit, steel beams are more widely used in bridges, which brings more significant vibration and noise problems. In this paper, the dynamic characteristics of a steel beam of groove profile are investigated through field test and numerical analysis. Firstly, under the hammering excitation, the vibration response of the slabs in a descending order are right web, left web and bottom slab. The vibration response is related to the distance from the response position to the excitation source and the stiffness of slabs. Then, a numerical model of the steel beam is established based on the hybrid FE-SEA method. The results of field test are consistent with the numerical simulation, which confirms the effectiveness of the hybrid FE-SEA method when analyzing the steel beam. Finally, by comparing the sound power level radiated from different slabs in three zones, it can be concluded that the sound power level is related to the distance from the test position to the excitation source. The overall sound power level will increase when canceling transverse connection system, and center excitation has a more significant effect than off-center excitation.

Gli stili APA, Harvard, Vancouver, ISO e altri

Offriamo sconti su tutti i piani premium per gli autori le cui opere sono incluse in raccolte letterarie tematiche. Contattaci per ottenere un codice promozionale unico!