scholarly journals Inferring low-dimensional latent descriptions of animal vocalizations

2019 ◽  
Author(s):  
Jack Goffinet ◽  
Richard Mooney ◽  
John Pearson
Keyword(s):  
Laboratory Mouse ◽  
Vocal Behavior ◽  
Acoustic Similarity ◽  
Acoustic Features ◽  
Data Driven Approach ◽  
Animal Vocalizations ◽  
Feature Values ◽  
Vocal Categories ◽  
Definition Of ◽  
Low Dimensional

AbstractVocalization is an essential medium for social and sexual signaling in most birds and mammals. Consequently, the analysis of vocal behavior is of great interest to fields such as neuroscience and linguistics. A standard approach to analyzing vocalization involves segmenting the sound stream into discrete vocal elements, calculating a number of handpicked acoustic features, and then using the feature values for subsequent quantitative analysis. While this approach has proven powerful, it suffers from several crucial limitations: First, handpicked acoustic features may miss important dimensions of variability that are important for communicative function. Second, many analyses assume vocalizations fall into discrete vocal categories, often without rigorous justification. Third, a syllable-level analysis requires a consistent definition of syllable boundaries, which is often difficult to maintain in practice and limits the sorts of structure one can find in the data. To address these shortcomings, we apply a data-driven approach based on the variational autoencoder (VAE), an unsupervised learning method, to the task of characterizing vocalizations in two model species: the laboratory mouse (Mus musculus) and the zebra finch (Taeniopygia guttata). We find that the VAE converges on a parsimonious representation of vocal behavior that outperforms handpicked acoustic features on a variety of common analysis tasks, including representing acoustic similarity and recovering a known effect of social context on birdsong. Additionally, we use our learned acoustic features to argue against the widespread view that mouse ultrasonic vocalizations form discrete syllable categories. Lastly, we present a novel “shotgun VAE” that can quantify moment-by-moment variability in vocalizations. In all, we show that data-derived acoustic features confirm and extend existing approaches while offering distinct advantages in several critical applications.

scholarly journals Low-dimensional learned feature spaces quantify individual and group differences in vocal repertoires

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Jack Goffinet ◽  
Samuel Brudner ◽  
Richard Mooney ◽  
John Pearson
Keyword(s):  
Unsupervised Learning ◽  
Zebra Finch ◽  
Laboratory Mouse ◽  
Statistical Testing ◽  
Vocal Behavior ◽  
Learning Approaches ◽  
Domain Specific ◽  
Feature Spaces ◽  
Common Strategy ◽  
Low Dimensional

Increases in the scale and complexity of behavioral data pose an increasing challenge for data analysis. A common strategy involves replacing entire behaviors with small numbers of handpicked, domain-specific features, but this approach suffers from several crucial limitations. For example, handpicked features may miss important dimensions of variability, and correlations among them complicate statistical testing. Here, by contrast, we apply the variational autoencoder (VAE), an unsupervised learning method, to learn features directly from data and quantify the vocal behavior of two model species: the laboratory mouse and the zebra finch. The VAE converges on a parsimonious representation that outperforms handpicked features on a variety of common analysis tasks, enables the measurement of moment-by-moment vocal variability on the timescale of tens of milliseconds in the zebra finch, provides strong evidence that mouse ultrasonic vocalizations do not cluster as is commonly believed, and captures the similarity of tutor and pupil birdsong with qualitatively higher fidelity than previous approaches. In all, we demonstrate the utility of modern unsupervised learning approaches to the quantification of complex and high-dimensional vocal behavior.

Extended-Range Prediction with Low-Dimensional, Stochastic-Dynamic Models: A Data-driven Approach

2012 ◽  
Author(s):  
Michael Ghil ◽  
Mickael D. Chekroun ◽  
Dmitri Kondrashov ◽  
Michael K. Tippett ◽  
Andrew Robertson ◽  
...  
Keyword(s):  
Dynamic Models ◽  
Data Driven ◽  
Stochastic Dynamic ◽  
Extended Range ◽  
Data Driven Approach ◽  
Low Dimensional

scholarly journals Definition of a scoring parameter to identify low-dimensional materials components

2019 ◽  
Vol 3 (3) ◽  
Author(s):  
Peter Mahler Larsen ◽  
Mohnish Pandey ◽  
Mikkel Strange ◽  
Karsten Wedel Jacobsen
Keyword(s):  
Definition Of ◽  
Low Dimensional ◽  
Low Dimensional Materials

scholarly journals Acoustic Characteristics of Cross-Laminated Timber Systems

2020 ◽  
Vol 12 (14) ◽  
pp. 5612
Author(s):  
Antonino Di Bella ◽  
Milica Mitrovic
Keyword(s):  
Environmental Benefits ◽  
Specific Reference ◽  
Acoustic Features ◽  
Acoustic Characteristics ◽  
Cross Laminated Timber ◽  
Acoustic Modelling ◽  
Improve Measurement ◽  
Reference Curves ◽  
Definition Of ◽  
Building Elements

The growing diffusion of cross-laminated timber structures (CLT) has been accompanied by extensive research on the peculiar characteristics of this construction system, mainly concerning its economic and environmental benefits, lifecycle, structural design, resistance to seismic actions, fire protection, and energy efficiency. Nevertheless, some aspects have not yet been fully analysed. These include both the knowledge of noise protection that CLT systems are able to offer in relation to the possible applications and combinations of building elements, and the definition of calculation methods necessary to support the acoustic design. This review focuses on the main acoustic features of CLT systems and investigate on the results of the most relevant research aimed to provide key information on the application of acoustic modelling in CLT buildings. The vibro-acoustic behaviour of the basic component of this system and their interaction through the joints has been addressed, as well as the possible ways to manage acoustic information for calculation accuracy improvement by calibration with data from on-site measurements during the construction phase. This study further suggests the opportunity to improve measurement standards with specific reference curves for the bare CLT building elements, in order to compare different acoustic linings and assemblies on the same base. In addition, this study allows to identify some topics in the literature that are not yet fully clarified, providing some insights on possible future developments in research and for the optimization of these products.

scholarly journals ‘Super' or just ‘above average'? Supershedders and the transmission of Escherichia coli O157:H7 among feedlot cattle

2015 ◽  
Vol 12 (110) ◽  
pp. 20150446 ◽  
Author(s):  
Simon E. F. Spencer ◽  
Thomas E. Besser ◽  
Rowland N. Cobbold ◽  
Nigel P. French
Keyword(s):  
Escherichia Coli ◽  
Stocking Density ◽  
Preliminary Evidence ◽  
Feedlot Cattle ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Key Characteristics ◽  
Data Driven Approach ◽  
Definition Of

Supershedders have been suggested to be major drivers of transmission of Escherichia coli O157:H7 ( E. coli O157:H7) among cattle in feedlot environments, despite our relatively limited knowledge of the processes that govern periods of high shedding within an individual animal. In this study, we attempt a data-driven approach, estimating the key characteristics of high shedding behaviour, including effects on transmission to other animals, directly from a study of natural E. coli O157:H7 infection of cattle in a research feedlot, in order to develop an evidence-based definition of supershedding. In contrast to the hypothesized role of supershedders, we found that high shedding individuals only modestly increased the risk of transmission: individuals shedding over 10 3 cfu g −1 faeces were estimated to pose a risk of transmission only 2.45 times greater than those shedding below that level. The data suggested that shedding above 10 3 cfu g −1 faeces was the most appropriate definition of supershedding behaviour and under this definition supershedding was surprisingly common, with an estimated prevalence of 31.3% in colonized individuals. We found no evidence that environmental contamination by faeces of shedding cattle contributed to transmission over timescales longer than 3 days and preliminary evidence that higher stocking density increased the risk of transmission.

scholarly journals Zwischenfach: Paradox or Paradigm?

2021 ◽  
Author(s):  
◽  
Elisabeth Harris
Keyword(s):  
Vocal Pedagogy ◽  
Practical Application ◽  
Mezzo Soprano ◽  
Gray Area ◽  
Standard Classification ◽  
Critical Insight ◽  
To Come ◽  
Vocal Categories ◽  
Definition Of ◽  
Dramatic Voice

<p>Singers within the operatic world are expected to conform to the strict limits and dictates of the Fachsystem. Casting directors and opera companies prefer to be informed of which particular ‘Fach-box’ you tick when auditioning and it is becoming increasingly important for career advancement and name recognition to remain within that box. Yet what happens when your voice does not operate strictly within the predetermined requirements of a particular box? Or if the vocal category you supposedly assume is already ambiguous and contentious? Jennifer Allen’s DMA thesis, An Analysis and Discussion of Zwischenfach Voices, provides invaluable critical insight surrounding this enigmatic concept of voice categorisation. Allen argues that despite advances within vocal pedagogy, there remains a ‘gray area’ within the discussion. This elusiveness, to which Allen refers, pertains directly to the Zwischenfach voice type. Translated literally from German, the word Zwischen means ‘between’ and ‘Fach’ refers specifically to vocal specialisation as a way of categorising singers according to the weight, range and colour of their voices. Thus, in its most basic form, a Zwischenfach voice denotes a voice that lies between the vocal categories of soprano and mezzo-soprano. However, whilst Dr Rudolf Kloiber’s Handbuch der Oper (a staple for the operatic world) provides a definitive guide to vocal categorisation and continues to influence casting throughout Germany and Europe, the corresponding American Boldrey Guide acknowledges Zwischenfach as a voice that cannot be classified precisely in one particular Fach or another. This lack of uniform approach highlights not only the potential flexibility of this voice, but also the paradoxical nature of attempting to define a voice that defies standard classification. Indeed, as a young singer currently singing high mezzo-soprano repertoire, I have found the Zwischenfach labelling to be a paradox, for the upper extension of my voice also enables me potentially to sing some soprano roles. Therefore, is it conceivable to postulate that this term is a misnomer and merely highlights the issues associated with being constrained within the Fachsystem? In order to come to terms with these issues, then, my analysis of Zwischenfach labelling requires a separation of voice categorisation and the Fachsystem and an ongoing critique of these systems throughout my exegesis. In an attempt to determine its practicalities, the limits that it can impose, and how its boundaries have not always functioned so neatly, my critique focuses on elements such as convenience, marketability and professional development and life. An exploration of the relevance of aspects such as range, tessitura, passaggi, timbre, agility, physical characteristics, pitch of the speaking voice, and scientific tests is also necessary. Once a definition of Zwischenfach is established, I consider the “in between” nature of this vocal category as I investigate roles that develop out of this into the realm of the heavier, more dramatic voice. Finally, I explore the implications of switching between Fächer and divulge how I incorporate the contradictions within this category with the successful management of the label. The piecing together of existing scholarship surrounding this field of research and the practical application to my own expanding repertoire is invaluable in facilitating the expansion of my knowledge in regard to my own progression through Zwischenfach repertoire and roles.</p>

scholarly journals Fault Prediction and Early-Detection in PV Power Plants based on Self-Organizing Maps

2021 ◽  
Author(s):  
Alessandro Betti ◽  
Mauro Tucci ◽  
Emanuele Crisostomi ◽  
Antonio Piazzi ◽  
Sami Barmada ◽  
...  
Keyword(s):  
Power Plants ◽  
Performance Indicator ◽  
Fault Prediction ◽  
Self Organizing Map ◽  
Self Organizing Maps ◽  
Data Driven Approach ◽  
On Line ◽  
Definition Of ◽  
Installed Capacity ◽  
Self Organizing

In this paper a novel and flexible solution for fault prediction based on data collected from Supervisory Control and Data Acquisition (SCADA) system is presented. Generic fault/status prediction is offered by means of a data driven approach based on a self-organizing map (SOM)and the definition of an original Key Performance Indicator (KPI). The model has been assessed on a park of three photovoltaic (PV) plants with installed capacity up to 10 MW, and on more than sixty inverter modules of three different technology brands. The results indicate that the proposed method is effective in predicting incipient generic faults in average up to 7 days in advance with true positives rate up to 95%. The model is easily deployable for on-line monitoring of anomalies on new PV plants and technologies, requiring only the availability of historical SCADA data, fault taxonomy and inverter electrical datasheet.

Numerical Analysis of Conservative Maps: A Possible Foundation of Nonextensive Phenomena

2004 ◽  
Author(s):  
Fulvio Baldovin
Keyword(s):  
Statistical Mechanics ◽  
High Energy Physics ◽  
Financial Analysis ◽  
Initial Conditions ◽  
Research Area ◽  
Distribution Functions ◽  
Point Of View ◽  
Dissipative Systems ◽  
Definition Of ◽  
Low Dimensional

We discuss the sensitivity to initial conditions and the entropy production of low-dimensional conservative maps, focusing on situations where the phase space presents complex (fractal-like) structures. We analyze numerically the standard map as a specific example and we observe a scenario that presents appealing analogies with anomalies detected in long-range Hamiltonian systems. We see how the Tsallis nonextensive formalism handles this situation both from a dynamical and from a statistical mechanics point of view…. In recent years, the Tsallis extension of the Boltzmann-Gibbs (BG) statistical mechanics [9, 26], usually referred to as nonextensive (NE) statistical mechanics, has become an intense and exciting research area (see, e.g., Tsallis [25]). The q-exponential distribution functions that emerge as a consequence of the NE formalism have been applied to an impressive variety of problems, ranging from turbulence, to high-energy physics, epilepsy, protein folding, and financial analysis. Yet, the foundation of this formalism, as well as the definition of its area of applicability, is still not completely understood, and it stands as a present challenge in the affirmation of the whole proposal. An intensive effort is currently being made to investigate this point, precisely in trying to understand: (1) which mechanisms lead to a crisis of the BG formalism; and (2) in these cases, does the NE formalism provide a "way out" to some of the problems? A possible approach to these questions comes from the study of the underlying dynamics that gives the basis for a statistical mechanic treatment of the system. This idea is not new. Einstein, in his critical remark about the validity of the Boltzmann principle [10], was one of the first to call attention to the relevance of a dynamical foundation of statistical mechanics. Another fundamental contribution is Krylov's seminal work [14] on the mixing properties of dynamical systems. In one-dimensional (dissipative) systems, intensive effort has been made to analyze the properties of the systems at the edge of chaos, i.e., at the critical poin that marks the transition between chaoticity and regularity [6, 8, 16, 19, 18, 23, 27].

scholarly journals The Observable Representation

Entropy ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 310
Author(s):  
L. Schulman
Keyword(s):  
Phase Transition ◽  
Euclidean Space ◽  
Complex Systems ◽  
Random Walks ◽  
Stochastic Dynamics ◽  
Dimensional Euclidean Space ◽  
Significant Feature ◽  
Original Space ◽  
Definition Of ◽  
Low Dimensional

The observable representation (OR) is an embedding of the space on which a stochastic dynamics is taking place into a low dimensional Euclidean space. The most significant feature of the OR is that it respects the dynamics. Examples are given in several areas: the definition of a phase transition (including metastable phases), random walks in which the OR recovers the original space, complex systems, systems in which the number of extrema exceed convenient viewing capacity, and systems in which successful features are displayed, but without the support of known theorems.

scholarly journals Alarming features: birds use specific acoustic properties to identify heterospecific alarm calls

2013 ◽  
Vol 280 (1754) ◽  
pp. 20122539 ◽  
Author(s):  
Pamela M. Fallow ◽  
Benjamin J. Pitcher ◽  
Robert D. Magrath
Keyword(s):  
Frequency Modulation ◽  
Alarm Call ◽  
Acoustic Properties ◽  
Alarm Calls ◽  
Acoustic Similarity ◽  
Acoustic Features ◽  
Alarm Signal ◽  
Antipredator Response ◽  
Malurus Cyaneus

Vertebrates that eavesdrop on heterospecific alarm calls must distinguish alarms from sounds that can safely be ignored, but the mechanisms for identifying heterospecific alarm calls are poorly understood. While vertebrates learn to identify heterospecific alarms through experience, some can also respond to unfamiliar alarm calls that are acoustically similar to conspecific alarm calls. We used synthetic calls to test the role of specific acoustic properties in alarm call identification by superb fairy-wrens, Malurus cyaneus . Individuals fled more often in response to synthetic calls with peak frequencies closer to those of conspecific calls, even if other acoustic features were dissimilar to that of fairy-wren calls. Further, they then spent more time in cover following calls that had both peak frequencies and frequency modulation rates closer to natural fairy-wren means. Thus, fairy-wrens use similarity in specific acoustic properties to identify alarms and adjust a two-stage antipredator response. Our study reveals how birds respond to heterospecific alarm calls without experience, and, together with previous work using playback of natural calls, shows that both acoustic similarity and learning are important for interspecific eavesdropping. More generally, this study reconciles contrasting views on the importance of alarm signal structure and learning in recognition of heterospecific alarms.

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