Vocal imitation for query by vocalisation

PhD ThesisThe human voice presents a rich and powerful medium for expressing sonic ideas such as musical sounds. This capability extends beyond the sounds used in speech, evidenced for example in the art form of beatboxing, and recent studies highlighting the utility of vocal imitation for communicating sonic concepts. Meanwhile, the advance of digital audio has resulted in huge libraries of sounds at the disposal of music producers and sound designers. This presents a compelling search problem: with larger search spaces, the task of navigating sound libraries has become increasingly difficult. The versatility and expressive nature of the voice provides a seemingly ideal medium for querying sound libraries, raising the question of how well humans are able to vocally imitate musical sounds, and how we might use the voice as a tool for search. In this thesis we address these questions by investigating the ability of musicians to vocalise synthesised and percussive sounds, and evaluate the suitability of different audio features for predicting the perceptual similarity between vocal imitations and imitated sounds. In the first experiment, musicians were tasked with imitating synthesised sounds with one or two time–varying feature envelopes applied. The results show that participants were able to imitate pitch, loudness, and spectral centroid features accurately, and that imitation accuracy was generally preserved when the imitated stimuli combined two, non-necessarily congruent features. This demonstrates the viability of using the voice as a natural means of expressing time series of two features simultaneously. The second experiment consisted of two parts. In a vocal production task, musicians were asked to imitate drum sounds. Listeners were then asked to rate the similarity between the imitations and sounds from the same category (e.g. kick, snare etc.). The results show that drum sounds received the highest similarity ratings when rated against their imitations (as opposed to imitations of another sound), and overall more than half the imitated sounds were correctly identified with above chance accuracy from the imitations, although this varied considerably between drum categories. The findings from the vocal imitation experiments highlight the capacity of musicians to vocally imitate musical sounds, and some limitations of non– verbal vocal expression. Finally, we investigated the performance of different audio features as predictors of perceptual similarity between the imitations and imitated sounds from the second experiment. We show that features learned using convolutional auto–encoders outperform a number of popular heuristic features for this task, and that preservation of temporal information is more important than spectral resolution for differentiating between the vocal imitations and same–category drum sounds

Mood and modality in torbatian dialect

This research is a fieldwork and has been done as follows. Torbatian dialect is a current language variation and its corpus has been collected by tape-recording and after transcribing, the materials have been analyzed on the basis of mood and modality. Mood is a category for which verb is inflected and it is used to indicate the syntactic relation of the main clause to other clauses in the sentence or to indicate the attitude of the speaker toward what she or he is saying as certainty or uncertainty, wish or command, emphasis or hesitancy. Mood, in this dialect, can be classified in two different ways: Morphologically and syntactically.From morphological point of view, this dialect distinguishes three moods: Indicative, Subjunctive and Imperative.Indicative mood indicates that a speaker presents the material with assurance. Subjunctive mood indicates a state of uncertainty. It may be possibility or conditional. Imperative mood indicates that the speaker commands or requests some action.From syntactic point of view, this dialect recognizes a whole series by the peculiarity of certain modal auxiliary verbs and other auxiliaries.Key words: dialect, dialectology, mood, modality, morphological, syntactica

Analysis of Technical Efficiency and Varietal Differences in Pistachio Production in Iran Using a Meta-Frontier Analysis

This paper reports on an analysis of technical efficiency and varietal differences in pistachio production in Iran. A random sample of 475 farmers was selected from the province of Kerman in 2003 and 2004. In this study, farmers are classified into three groups according to the variety of tree they planted. The three main varieties of pistachio trees planted are Kalleh- Ghuchi, Fandoghi and Akbari. The technical efficiency indices are computed using three approaches. First, a standard stochastic production frontier was employed using pooled data. Secondly, stochastic frontier production functions were estimated for each variety (separately). Lastly, the meta-frontier approach was used because production varieties and technologies are expected to differ between the three varieties. Use of this method enabled technical efficiency scores to be corrected by the coefficient of the variety-technology gap ratio (VTGR). Estimates of the frontier were obtained assuming a translog functional form. Results indicate that the mean values of technical efficiency in 2003 and 2004 for the pooled frontier, variety group frontiers and meta-frontier across all data are 54 per cent, 55 per cent and 62 per cent, respectively. The mean value of VTGR in 2003 and 2004 varies from 0.58 for the Kalleh-Ghuchi variety to 0.68 for the Fandoghi variety. These results show the importance of taking into account the differences in frontiers imposed by different tree varieties.pistachio, stochastic meta-frontier, production function, technical efficiency, Iranian agriculture, Productivity Analysis, C21, Q12, Q16, Q55, R58,

Dark energy reconstruction based on the PADE approximation; an expansion around the Λ\LambdaCDM

We study the dynamical properties of dark energy based on a large family of PADE parameterizations for which the dark energy density evolves as a ratio between two polynomials in the scale factor of the universe. Using the latest cosmological data we perform a standard likelihood analysis in order to place constraints on the main cosmological parameters of different PADE models. We find that the basic cosmological parameters, namely $(\Omega_{m0},h,\sigma_{8})$ are practically the same for all PADE parametrizations explored here. Concerning the free parameters which are related to dark energy we show that the best fit values indicate that the equation of state parameter at the present time is in the phantom regime ($w-1$ at $1\sigma$ level. Finally, for the current family of PADE parametrizations we test their ability, via AIC and Jeffreys' scale, to deviate from $\Lambda$CDM cosmology. Among the current PADE parametrizations, the model which contains two dark energy parameters is the one for which a small but non-zero deviation from $\Lambda$CDM cosmology is slightly allowed by AIC test. Moreover, based on Jeffreys' scale we show that a deviation from $\Lambda$CDM cosmology is also allowed and thus the possibility of having a dynamical dark energy in the form of PADE parametrization cannot be excluded.Comment: Accepted for publication in EPJ

Evaluating the user experience of acoustic data transmission A study of sharing data between mobile devices using sound

Users of smart devices frequently need to exchange data with people nearby to them. Yet despite the availability of various communication methods, data exchange between co-located devices is often complicated by technical and user experience barriers. A potential solution to these issues is the emerging technology of device-to-device acoustic data transmission. In this work, we investigate the medium-specific properties of sound as a data exchange mechanism, and question how these contribute to the user experience of sharing data. We present a user study comparing three wireless communication technologies (acoustic data transmission, QR codes and Bluetooth), when used for a common and familiar scenario: peer-to-peer sharing of contact information. Overall, the results show that acoustic data transmission provides a rapid means of transferring data (mean transaction time of 2.4 s), in contrast to Bluetooth (8.3 s) and QR (6.3 s), whilst requiring minimal physical effort and user coordination. All QR code transactions were successful on the first attempt; however, some acoustic (5.6%) and Bluetooth (16.7%) transactions required multiple attempts to successfully share a contact. Participants also provided feedback on their user experience via surveys and semi-structured interviews. Perceived transaction time, physical effort, and connectivity issues. Specifically, users expressed frustration with Bluetooth due to device selection issues, and with QR for the physical coordination required to scan codes. The findings indicate that acoustic data transmission has unique advantages in facilitating information sharing and interaction between co-located users