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Publications

Publications by CTM

2020

Orofacial Trauma on the Anterior Zone of a Trumpet's Player Maxilla: Concept of the Oral Rehabilitation-A Case Report

Authors
Clemente, MP; Moreira, A; Carvalho, N; Bernardes, G; Ferreira, AP; Amarante, JM; Mendes, J;

Publication
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH

Abstract
Background: The occurrence of an orofacial trauma can originate health, social, economic and professional problems. A 13-year boy suffered the avulsion of tooth 11 and 21, lost at the scenario. Methods: Three intraoral appliances were manufactured: A Hawley appliance with a central expansion screw and two central incisors (1), trumpet edentulous anterior tooth appliance (2) and a customized splint (3) were designed as part of the rehabilitation procedure. Objectively assessing the sound quality of the trumpet player with these new devices in terms of its spectral, temporal, and spectro-temporal audio properties. A linear frequency response microphone was adopted for precision measurement of pitch, loudness, and timbre descriptors. Results: Pitch deviations may result from the different intra-oral appliances due to the alteration of the mouth cavity, respectively, the area occupied and modification/interaction with the anatomy. This investigation supports the findings that the intra-oral appliance which occupies less volume is the best solution in terms of sound quality. Conclusions: Young wind instrumentalists should have dental impressions of their teeth made, so their dentist has the most reliable anatomy of the natural teeth in case of an orofacial trauma. Likewise, the registration of their sound quality should be done regularly to have standard parameters for comparison.

2020

Revisiting harmonic change detection

Authors
Ramoneda, P; Bernardes, G;

Publication
149th Audio Engineering Society Convention 2020, AES 2020

Abstract
In this paper, we advance an enhanced method for computing Harte et al.’s (2006) Harmonic Change Detection Function (HCDF), which aims to detect harmonic transitions in musical audio signals. Each of the HCDF component blocks is revisited in light of recent advances in harmonic description and transformation. To evaluate our proposal, we compute an exhaustive grid search to compare the multiple proposed algorithms and a large set of parameterizations across four large style-specific musical datasets. Our results show that the newly proposed methods and parameter optimization improve the detection of harmonic changes by 5.57% (f-score) with respect to previous methods. Furthermore, while guaranteeing recall values at >99%, our other method improves precision by 6.28%.

2020

TIV.lib: an open-source library for the tonal description of musical audio

Authors
Ramires, A; Bernardes, G; Davies, MEP; Serra, X;

Publication
CoRR

Abstract
In this paper, we present TIV.lib, an open-source library for the content-based tonal description of musical audio signals. Its main novelty relies on the perceptually-inspired Tonal Interval Vector space based on the Discrete Fourier transform, from which multiple instantaneous and global representations, descriptors and metrics are computed-e.g., harmonic change, dissonance, diatonicity, and musical key. The library is cross-platform, implemented in Python and the graphical programming language Pure Data, and can be used in both online and offline scenarios. Of note is its potential for enhanced Music Information Retrieval, where tonal descriptors sit at the core of numerous methods and applications.

2020

Interfacing sounds: Hierarchical audio content morphologies for creative re-purposing in eargram 2.0

Authors
Bernardes, G;

Publication
Proceedings of the International Conference on New Interfaces for Musical Expression

Abstract
Audio content-based processing has become a pervasive methodology for techno-fluent musicians. System architectures typically create thumbnail audio descriptions, based on signal processing methods, to visualize, retrieve and transform musical audio efficiently. Towards enhanced usability of these descriptor-based frameworks for the music community, the paper advances a minimal content-based audio description scheme, rooted on primary musical notation attributes at the threefold sound object, meso and macro hierarchies. Multiple perceptually-guided viewpoints from rhythmic, harmonic, timbral and dynamic attributes define a discrete and finite alphabet with minimal formal and subjective assumptions using unsupervised and user-guided methods. The Factor Oracle automaton is then adopted to model and visualize temporal morphology. The generative musical applications enabled by the descriptor-based framework at multiple structural hierarchies are discussed. © 2020, Steering Committee of the International Conference on New Interfaces for Musical Expression. All rights reserved.

2020

Examining Temporal Trends and Design Goals of Digital Music Instruments for Education in NIME: A Proposed Taxonomy

Authors
Margarida Pessoa; Cláudio Parauta; Pedro Luís; Isabela Almeida; Gilberto Bernardes;

Publication

Abstract
This paper presents an overview of the design principles behind Digital Music Instruments (DMIs) for education across all editions of the International Conference on New Interfaces for Music Expression (NIME). We compiled a comprehensive catalogue of over hundred DMIs with varying degrees of applicability in the educational practice. Each catalogue entry is annotated according to a proposed taxonomy for DMIs for education, rooted in the mechanics of control, mapping and feedback of an interactive music system, along with the required expertise of target user groups and the instrument learning curve. Global statistics unpack underlying trends and design goals across the chronological period of the NIME conference. In recent years, we note a growing number of DMIs targeting non-experts and with reduced requirements in terms of expertise. Stemming from the identified trends, we discuss future challenges in the design of DMIs for education towards enhanced degrees of variation and unpredictability.

2020

Analysis and Design of a Polar Digitally Modulated CMOS PA Based on Switched Constant-Current

Authors
Gomes, R; Duarte, C; Pedro, JC;

Publication
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES

Abstract
Typical polar digital power amplifiers (DPAs) employ unit-cells operated in class-E or D-1, denoting a switched-resistance operation which degrades linearity. Besides introducing higher demand on digital predistortion (DPD), it also requires extra quantization bits, impacting the overall efficiency and system complexity. To address this, the present work makes use of an optimized constant-current cascode unit-cell which is combined with reduced conduction angle to achieve linear and efficient operation, while minimizing the effort on DPD and/or calibration. A design strategy is developed which focuses on the cascode bias voltage and transistor relative dimensions as design parameters, allowing cascode efficiency optimization without compromising linearity or reliability. A single-ended polar switched constant-current DPA is implemented in 180-nm standard CMOS. Continuous-wave measurements performed at 800 MHz demonstrate an output power of 24 dBm with a PAE of 47%. The DPA dynamic behavior was tested with a 64-QAM signal with 10 MS/s, achieving an average PAE of 20.9% with a peak-to-average power ratio (PAPR) of 8.7 dB and adjacent-channel leakage ratio (ACLR) = 40.34 dB. These results demonstrate comparable performance with the prior art while using only 6-bits clocked at 100 MHz baseband sampling frequency.

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