Discriminant Analysis as a Tool for Detecting the Acoustic Signals of Termites Coptotermes Curvignathus (Isoptera: Rhinotermitidae)

Various methods for termite detection have been developed, one of them is purely based on the acoustic signal. However, that method still has a weakness, wherein it is difficult to separate the signal generated by the termite or the noise from the environment. The combination of the feature extraction at the acoustic signal and the classification model is expected to overcome the weakness. In this investigation, we inserted 220 subterranean termites Coptotermes curvignathus into pine wood for feeding activity and observed its acoustic signal. In addition, three acoustic features (i.e., short-term energy, entropy and zero moment power) were proposed to recognize the termite's acoustic signal. Subsequently, these features will be analyzed and combined with discriminant analysis to produce the robust classification model. According to the numerical results, the integrated discriminant analysis and the acoustic feature in our termite detection system has an 83.75% accuracy

Sonic Phantoms Compositional explorations of perceptual phantom patterns

I use the term ‘Sonic Phantoms’ to refer as a whole to a cohesive collection of sound compositions that I have developed over the past five years (2009-2014; fifty pieces, structured in four separate collections / series), dealing at a fundamental level with perceptual auditory illusions. For the creation of this compositional body of work, I have developed a syncretic approach that encompasses and coalesces all kinds of sources, materials, techniques and compositional tools: voices (real and synthetic), field recordings (involving wilderness expeditions worldwide), instrument manipulation (including novel ways of ‘preparation’), object amplification, improvisation and recording studio techniques. This manifests a sonic-based and perceptive-based understanding of the compositional work, as an implicitly proposed paradigm for any equivalent work in terms of its trans-technological, phenomena-based nature. By means of the collection of pieces created and the research and contextualisation presented, my work with ‘Sonic Phantoms’ aims at bringing into focus, shaping and defining a specific and dedicated compositional realm that considers auditory illusions as essential components of the work and not simply mere side effects. I play with sonic materials that are either naturally ambiguous or have been composed to attain this quality, in order to exploit the potential for apophenia to manifest, bringing with it the ‘phantasmatic’ presence. Both my compositions and research work integrate and synergise a considerable number of disparate musical traditions (Western and non-Western), techno-historical moments (from ancient / archaic to electronic / computer-age techniques), cultural frameworks (from ‘serious’ to ‘popular’), and fields of interest / expertise (from the psychological to the musical), into a personal and cohesive compositional whole. All these diverse elements are not simply mentioned or referenced, but have rather defined, structured and formed the resulting compositional work

Ultra-high-speed imaging of bubbles interacting with cells and tissue

Ultrasound contrast microbubbles are exploited in molecular imaging, where bubbles are directed to target cells and where their high-scattering cross section to ultrasound allows for the detection of pathologies at a molecular level. In therapeutic applications vibrating bubbles close to cells may alter the permeability of cell membranes, and these systems are therefore highly interesting for drug and gene delivery applications using ultrasound. In a more extreme regime bubbles are driven through shock waves to sonoporate or kill cells through intense stresses or jets following inertial bubble collapse. Here, we elucidate some of the underlying mechanisms using the 25-Mfps camera Brandaris128, resolving the bubble dynamics and its interactions with cells. We quantify acoustic microstreaming around oscillating bubbles close to rigid walls and evaluate the shear stresses on nonadherent cells. In a study on the fluid dynamical interaction of cavitation bubbles with adherent cells, we find that the nonspherical collapse of bubbles is responsible for cell detachment. We also visualized the dynamics of vibrating microbubbles in contact with endothelial cells followed by fluorescent imaging of the transport of propidium iodide, used as a membrane integrity probe, into these cells showing a direct correlation between cell deformation and cell membrane permeability

Perceptual learning of context-sensitive phonetic detail

[Abstract abbreviated due to inability of DSpace@Cambridge to display phonetic symbols. Please see the full abstract in the attached pdf file.] Although familiarity with a talker or accent is known to facilitate perception, it is not clear what underlies this phenomenon. Previous research has focused primarily on whether listeners can learn to associate novel phonetic characteristics with low-level units such as features or phonemes. However, this neglects the potential role of phonetic information at many other levels of representation. To address this shortcoming, this thesis investigated perceptual learning of systematic phonetic detail relating to higher levels of linguistic structure, including prosodic, grammatical and morphological contexts. Furthermore, in contrast to many previous studies, this research used relatively natural stimuli and tasks, thus maximising its relevance to perceptual learning in ordinary listening situations. This research shows that listeners can update their phonetic representations in response to incoming information and its relation to linguistic-structural context. In addition, certain patterns of systematic phonetic detail were more learnable than others. These findings are used to inform an account of how new information is integrated with prior experience in speech processing, within a framework that emphasises the importance of phonetic detail at multiple levels of representation.This work was funded by an AHRC grant