AN UNDERSTANDING OF STYLE OF BAROQUE ORNAMENTATION IN HANDEL’S OPERATIC ARIAS: A STUDY OF SELECTED RECORDINGS (1950s – 2010s)

From the early 20th century to the present, new discoveries in Handel scholarship and changing ideas of Baroque performance practice have greatly affected the manner in which Handel’s operas and individual arias have been performed. Since the appearance of the first volumes of the Hallische Handel-Ausgabe in 1958, Handel’s works have experienced a renewed appreciation among performers and scholars alike, including countless opera productions. Since the introduction of the CD, many talented singers have published recordings of his operas and individual arias, influenced by a greater under-standing of period-performance practices and audience expectations. As such, performers are expected to be conversant in Baroque-period performance practices, especially improvised embellishments. However, many published recordings of Baroque arias seem more focused on demonstrating virtuosic vocal technique than historically informed ornaments, leading to an indiscriminate application of excessive, stylistically inappropriate embellishments among performers. Handel’s Italian singers were experts in vocal ornamentation; thus, he did not notate expected ornaments on the scores. However, Winton Dean’s composite volume Three Ornamented Arias provides Handel’s notations of intended embellishments to these works. In order to consider period-appropriate embellishments in other operatic arias by Handel, this study will 1) compare Handel’s notated embellishments in relation to the unembellished score, and 2) examine Robert Donington’s recommendations for specific ornaments in Baroque Music: Style and Performance. In doing so, I will provide an authentic, historically informed view of embellishments and ornaments in Baroque music. This project will focus on the performance practice of Baroque ornamentation in Handel’s arias in the 20th and 21st centuries, as reflected in authentic Baroque performance practice and selected recordings. Handel’s four soprano arias: Lascia ch’io pianga, V’adoro pupille, Piangerò la sorte mia, and Tornami a vagheggiar will be discussed to compare changing ideas of vocal ornamentation through selected recordings from the late 1950s and until the 2010s. The selection of recordings will be considered in relation to the ‘well-known’ virtuosos, Baroque music singers, and conductors as well. Based on the investigation of Handelian performance practices, this paper will provide a framework for critically evaluating improvised embellishments in published recordings, which may be 1) deficiently ornamented, 2) stylistically appropriate, or 3) excessively ornamented

Introduction to Navigation Systems

Navigation is the method for determining position, speed, and direction of the object. That is mainly classified into two groups: physical model-based methods (PMMs) and external data-based methods (EDMs). Examples of PMMs are inertial navigation systems (INS) and dead-reckoning navigation. They determine the existing position of an object by measuring various changes in its state, such as velocity and acceleration. Representative EDMs is the global navigation satellite system (GNSS). In the case of spacecraft, auxiliary navigation systems using data compression were proposed. In the case of low earth orbit satellites, the deviations between nominal and real orbit are compressed in the form of Fourier coefficients by using the periodic characteristics of the trajectory. In the event of Deep space explorer, B-spline based orbit compression and transmission was proposed

Punctuation Restoration Improves Structure Understanding without Supervision

Unsupervised learning objectives like language modeling and de-noising constitute a significant part in producing pre-trained models that perform various downstream applications from natural language understanding to conversational tasks. However, despite impressive generative capabilities of recent large language models, their abilities to capture syntactic or semantic structure within text lag behind. We hypothesize that the mismatch between linguistic performance and competence in machines is attributable to insufficient transfer of linguistic structure knowledge to computational systems with currently popular pre-training objectives. We show that punctuation restoration as a learning objective improves in- and out-of-distribution performance on structure-related tasks like named entity recognition, open information extraction, chunking, and part-of-speech tagging. Punctuation restoration is an effective learning objective that can improve structure understanding and yield a more robust structure-aware representations of natural language.Comment: 10 pages, 1 figure, 6 table

Representation Selective Self-distillation and wav2vec 2.0 Feature Exploration for Spoof-aware Speaker Verification

Text-to-speech and voice conversion studies are constantly improving to the extent where they can produce synthetic speech almost indistinguishable from bona fide human speech. In this regrad, the importance of countermeasures (CM) against synthetic voice attacks of the automatic speaker verification (ASV) systems emerges. Nonetheless, most end-to-end spoofing detection networks are black box systems, and the answer to what is an effective representation for finding artifacts still remains veiled. In this paper, we examine which feature space can effectively represent synthetic artifacts using wav2vec 2.0, and study which architecture can effectively utilize the space. Our study allows us to analyze which attribute of speech signals is advantageous for the CM systems. The proposed CM system achieved 0.31% equal error rate (EER) on ASVspoof 2019 LA evaluation set for the spoof detection task. We further propose a simple yet effective spoofing aware speaker verification (SASV) methodology, which takes advantage of the disentangled representations from our countermeasure system. Evaluation performed with the SASV Challenge 2022 database show 1.08% of SASV EER. Quantitative analysis shows that using the explored feature space of wav2vec 2.0 advantages both spoofing CM and SASV.Comment: Submitted to Interspeech 202

Flooding with Absorption: An Efficient Protocol for Heterogeneous Bandits over Complex Networks

Multi-armed bandits are extensively used to model sequential decision-making, making them ubiquitous in many real-life applications such as online recommender systems and wireless networking. We consider a multi-agent setting where each agent solves their own bandit instance endowed with a different set of arms. Their goal is to minimize their group regret while collaborating via some communication protocol over a given network. Previous literature on this problem only considered arm heterogeneity and networked agents separately. In this work, we introduce a setting that encompasses both features. For this novel setting, we first provide a rigorous regret analysis for a standard flooding protocol combined with the classic UCB policy. Then, to mitigate the issue of high communication costs incurred by flooding in complex networks, we propose a new protocol called Flooding with Absorption (FwA). We provide a theoretical analysis of the resulting regret bound and discuss the advantages of using FwA over flooding. Lastly, we experimentally verify on various scenarios, including dynamic networks, that FwA leads to significantly lower communication costs despite minimal regret performance loss compared to other network protocols.Comment: 25 pages, 6 figures. Accepted to the 27th International Conference on Principles of Distributed Systems (OPODIS 2023) - Best Student Pape

DEVELOPMENT OF SMALL MOLECULES AND PEPTIDOMIMETIC LIGANDS TARGETING EPIGENETIC READER PROTEINS

The eukaryotic genome is assembled into chromatin, the complex of DNA/RNA, and histones that occupies the nucleus, and structural changes in chromatin are considered to regulate transcription from the genome by controlling the accessibility of the underlying DNA. The post-translational modifications (PTMs) on histones, including acetylation and methylation, are controlled by writers, erasers, and readers, and their dysregulation is implicated in a variety of disease states such as cancer, developmental disorders, and neurological illnesses. Epigenetic readers recognize these histone modifications, which have been deposited by the epigenetic writers, and recruit additional multi-subunit protein complexes which in turn regulate chromatin accessibility and gene activity. For example, Polycomb group (PcG) complexes form a transcriptionally repressive system by modifying chromatin structure at target genes. PcG complexes are responsive to local chromatin structure in eukaryotes, however the details of regulation by PcG complexes is still not fully understood. Several chromatin readers have multiple domains that can together recognize more than one PTM, and their multivalent interactions are considered an integral feature of chromatin regulation. Our lab has hypothesized that the relationship between the distance of two specific PTM marks and the spacing of the individual reader domains within the protein are important for these multivalent interactions. Additionally, our lab has recently discovered several peptide-derived chemical probes for PcG subunit proteins such as an in vitro ligand for embryonic ectoderm development (EED) in Polycomb Repressive Complex 2 (PRC2), and a cellular chemical probe for the chromobox homolg (CBX) readers in Polycomb Repressive Complex 1 (PRC1) through both ligand-based and structure-based approaches. Here, we used three different approaches to explore chromatin regulation: development of multivalent inhibitors to address the biophysical basis for chromatin multivalent regulation; mutant-specific allosteric activators to demonstrate the feasibility of targeted therapeutics which could potentially correct the mutant phenotype of an epigenetic regulator; and selective chemical probes for methyl-lysine reader domains to assess the roles of specific reader proteins in cancer.Doctor of Philosoph