A Framework for Bioacoustic Vocalization Analysis Using Hidden Markov Models

Using Hidden Markov Models (HMMs) as a recognition framework for automatic classification of animal vocalizations has a number of benefits, including the ability to handle duration variability through nonlinear time alignment, the ability to incorporate complex language or recognition constraints, and easy extendibility to continuous recognition and detection domains. In this work, we apply HMMs to several different species and bioacoustic tasks using generalized spectral features that can be easily adjusted across species and HMM network topologies suited to each task. This experimental work includes a simple call type classification task using one HMM per vocalization for repertoire analysis of Asian elephants, a language-constrained song recognition task using syllable models as base units for ortolan bunting vocalizations, and a stress stimulus differentiation task in poultry vocalizations using a non-sequential model via a one-state HMM with Gaussian mixtures. Results show strong performance across all tasks and illustrate the flexibility of the HMM framework for a variety of species, vocalization types, and analysis tasks

A Framework for Bioacoustic Vocalization Analysis Using Hidden Markov Models

Using Hidden Markov Models (HMMs) as a recognition framework for automatic classification of animal vocalizations has a number of benefits, including the ability to handle duration variability through nonlinear time alignment, the ability to incorporate complex language or recognition constraints, and easy extendibility to continuous recognition and detection domains. In this work, we apply HMMs to several different species and bioacoustic tasks using generalized spectral features that can be easily adjusted across species and HMM network topologies suited to each task. This experimental work includes a simple call type classification task using one HMM per vocalization for repertoire analysis of Asian elephants, a language-constrained song recognition task using syllable models as base units for ortolan bunting vocalizations, and a stress stimulus differentiation task in poultry vocalizations using a non-sequential model via a one-state HMM with Gaussian mixtures. Results show strong performance across all tasks and illustrate the flexibility of the HMM framework for a variety of species, vocalization types, and analysis tasks

Schools and skills of critical thinking for urban design

© 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group. This paper explores possible ways in which urban design can engage with critical thinking and critical theory. After a brief explanation of the terms, with particular attention to the Frankfurt School of thought, it provides various answers to the question as to whether urban design is critical or not. One categorization applied to planning critical theory is then used to explain the potential for employing critical theories in urban design. Critical thinking skills are then argued to be helpful for enriching the literature of urban design in order to achieve better practice. The conclusion is that urban design can benefit from critical creativity, which is an embodiment of critical thinking within the limits imposed onto creativity. In this paper, the ways in which urban design can engage with both critical theory and with critical thinking are explored in order to achieve better critical creativity in the field

Analysis and Classification of Sounds Produced by Asian Elephants (\u3ci\u3eElephas Maximus\u3c/i\u3e)

Relatively little is known about the vocal repertoire of Asian elephants (Elephas maximus), and a categorization of basic call types and modifications of these call types by quantitative acoustic parameters is needed to examine acoustic variability within and among call types, to examine individuality, to determine communicative function of calls via playback, to compare species and populations, and to develop rigorous call recognition algorithms for monitoring populations. This study defines an acoustic repertoire of Asian elephants based on acoustic parameters, compares repertoire usage among groups and individuals, and validates structural distinction among call types through comparison of manual and automated classification methods. Recordings were made of captive elephants at the Oregon Zoo in Portland, OR, USA, and of domesticated elephants in Thailand. Acoustic and behavioral data were collected in a variety of social contexts and environmental noise conditions. Calls were classified using perceptual aural cues plus visual inspection of spectrograms, then acoustic features were measured, then automated classification was run. The final repertoire was defined by six basic call types (Bark, Roar, Rumble, Bark, Squeal, Squeal, and Trumpet), five call combinations and modifications with these basic calls forming their constituent parts (Roar-Rumble, Squeal-Squeak, Squeak train, Squeak-Bark, and Trumpet-Roar), and the Blow. Given the consistency of classifications results for calls from geographically and socially disparate subject groups, it seems possible that automated call detection algorithms could be developed for acoustic monitoring of Asian elephants

Assessing Well-being of Asian Elephants (\u3ci\u3eElephas maximus\u3c/i\u3e) Through Major Events and Transitions, with Development and Aging, and Husbandry Changes

In this body of research, reproductive and adrenal hormones and behavior were used to evaluate individual and group responses to physiological, social, and environmental changes in zoo-housed Asian elephants, considering factors of sex, age, and life stage. Animals experience physiological, social, and environmental changes as part of their natural history and individual life experience. Measures of both positive and negative states are needed to assess the impact of these changes at the individual and group level. Such measures can help us better understand how animals cope with a changing environment, and can help inform management decisions. Through longitudinal analyses of more than 20 years of gonadal and adrenal hormone data (Chapters 2 and 3), we confirmed the presence of intrinsic glucocorticoid (GC) patterns associated with reproductive state in male and female Asian elephants, providing further evidence that GCs play a role in normal reproductive function. In females, circulating cortisol was higher in the follicular phase compared to the luteal phase of the ovarian cycle, and highest in lactational anestrous compared to all other reproductive states. In bulls, circulating cortisol covaried positively with testosterone and musth, as observed in previous studies of elephants and during the analogous condition of rut in other ungulates. Age-related changes in cortisol were observed in both sexes, and some individuals experienced higher rates of change in cortisol in one phase of their reproductive cycle versus another. In bulls, testosterone increased after puberty but decreased with advancing age. Concentrations of GCs covaried more consistently with physiological changes than with social changes in both sexes. Overall, the elephants in these studies showed adaptive adrenal responses to change, and they also exhibited substantial individuality in adrenal response to social life events. These findings reinforce the need to assess welfare on an individual basis and to consider factors influencing the impact of perceived stressors, such as social support, temperament, and life history. The study conducted to monitor an elephant herd through transition to a new habitat (Chapter 4) provided further insights on habitat features that help us meet the physiological, psychological and social needs of elephants under human care, and helped identify which of those features may be most beneficial for enhancing welfare. The complexity and flexibility of the new habitat was effective in improving overall health and welfare by encouraging activity and providing meaningful challenges and the opportunity to express more appetitive behaviors. The new habitat also offered increased control over environmental conditions and social interactions, and the space and resource distribution helped to support changing herd dynamics and greater social equity. Overall, these studies helped deepen our understanding of Asian elephant physiology, and highlight the importance of taking intrinsic patterns of hormone secretion into account when evaluating the impact of external changes. New insights into the welfare impact of habitat and husbandry factors help inform future housing and management decisions. Finally, a better understanding of the impact of social change and resiliency in response to real and perceived stressors allows us to improve social management to enhance welfare in both captive settings and free-ranging environments