232 research outputs found
Harmonic analysis of music using combinatory categorial grammar
FP7 grant 249520 (GRAMPLUS)Various patterns of the organization of Western tonal music exhibit hierarchical structure,
among them the harmonic progressions underlying melodies and the metre underlying
rhythmic patterns. Recognizing these structures is an important part of unconscious
human cognitive processing of music. Since the prosody and syntax of natural
languages are commonly analysed with similar hierarchical structures, it is reasonable
to expect that the techniques used to identify these structures automatically in natural
language might also be applied to the automatic interpretation of music.
In natural language processing (NLP), analysing the syntactic structure of a sentence
is prerequisite to semantic interpretation. The analysis is made difficult by the
high degree of ambiguity in even moderately long sentences. In music, a similar sort of
structural analysis, with a similar degree of ambiguity, is fundamental to tasks such as
key identification and score transcription. These and other tasks depend on harmonic
and rhythmic analyses. There is a long history of applying linguistic analysis techniques
to musical analysis. In recent years, statistical modelling, in particular in the
form of probabilistic models, has become ubiquitous in NLP for large-scale practical
analysis of language. The focus of the present work is the application of statistical
parsing to automatic harmonic analysis of music.
This thesis demonstrates that statistical parsing techniques, adapted from NLP with
little modification, can be successfully applied to recovering the harmonic structure
underlying music. It shows first how a type of formal grammar based on one used
for linguistic syntactic processing, Combinatory Categorial Grammar (CCG), can be
used to analyse the hierarchical structure of chord sequences. I introduce a formal
language similar to first-order predicate logical to express the hierarchical tonal harmonic
relationships between chords. The syntactic grammar formalism then serves as
a mechanism to map an unstructured chord sequence onto its structured analysis.
In NLP, the high degree of ambiguity of the analysis means that a parser must
consider a huge number of possible structures. Chart parsing provides an efficient
mechanism to explore them. Statistical models allow the parser to use information
about structures seen before in a training corpus to eliminate improbable interpretations
early on in the process and to rank the final analyses by plausibility. To apply the
same techniques to harmonic analysis of chord sequences, a corpus of tonal jazz chord
sequences annotated by hand with harmonic analyses is constructed. Two statistical
parsing techniques are adapted to the present task and evaluated on their success at recovering the annotated structures. The experiments show that parsing using a statistical
model of syntactic derivations is more successful than a Markovian baseline
model at recovering harmonic structure. In addition, the practical technique of statistical
supertagging serves to speed up parsing without any loss in accuracy.
This approach to recovering harmonic structure can be extended to the analysis of
performance data symbolically represented as notes. Experiments using some simple
proof-of-concept extensions of the above parsing models demonstrate one probabilistic
approach to this. The results reported provide a baseline for future work on the task of
harmonic analysis of performances
A Comparison of Unsupervised Methods for Ad hoc Cross-Lingual Document Retrieval
We address the problem of linking related documents across languages in a multilingual collection. We evaluate three diverse unsupervised methods to represent and compare documents: (1) multilingual topic model; (2) cross-lingual document embeddings; and (3) Wasserstein distance. We test the performance of these methods in retrieving news articles in Swedish that are known to be related to a given Finnish article. The results show that ensembles of the methods outperform the stand-alone methods, suggesting that they capture complementary characteristics of the documents.Peer reviewe
Structural studies and polymorphism in amorphous solids and liquids at high pressure
When amorphous materials are compressed their structures are expected to change in response to densification. In some cases, the changes in amorphous structure can be discontinuous and they can even have the character of first-order phase transitions. This is a phenomenon referred to as polyamorphism. Most evidence for polyamorphic transitions between low and high density liquids or analogous transformations between amorphous forms of the same substance to date has been indirect and based on the changes in thermodynamic and other structure-related properties with pressure. Recent studies using advanced X-ray and neutron scattering methods combined with molecular dynamics simulations are now revealing the details of structural changes in polyamorphic systems as a function of pressure. Various "two state'' or "two species'' models are used to understand the anomalous densification behaviour of liquids with melting curve maxima or regions of negative melting slope. Thermodynamic analysis of the two state model leads to the possibility of low- to high-density liquid transitions caused by differences in bulk thermodynamic properties between different amorphous forms and on the degree of cooperativity between low- and high-density structural configurations. The potential occurrence of first-order transitions between supercooled liquids is identified as a critical-like phenomenon. In this tutorial review we discuss the background to polyamorphism, incorporating the experimental observations, simulation studies and the two-state models. We also describe work carried on several systems that are considered to be polyamorphic
Interrogating the prevention approach of the Housing (Wales) Act 2014 for people with mental health needs who are homeless
Rates of homelessness and poor mental health present significant challenges across the globe. In this article, we explore how these intersecting issues have been addressed in Wales through Part 2 of the Housing (Wales) Act 2014 through a paradigm shift towards a prevention model. This article reports findings from a study (conducted between 2016 and 2018) which evaluated the processes and impacts of the Act against the backdrop of welfare reform and systemic changes taking place in Wales and the UK. Using new evidence, we offer a critical examination of how homelessness prevention policy operates in practice and how social values and power affect policy implementation. We offer new evidence of the translation of policy into practice through the experiences of two stakeholder groups: people with mental health needs and service providers. In doing so, we offer a critique of how policy and practice could be modified to improve outcomes for homeless people with implications for prevention policy in Wales and in other contexts and different welfare regimes
Exact rings and semirings
We introduce and study an abstract class of semirings, which we call exact
semirings, defined by a Hahn-Banach-type separation property on modules. Our
motivation comes from the tropical semiring, and in particular a desire to
understand the often surprising extent to which it behaves like a field. The
definition of exactness abstracts an elementary property of fields and the
tropical semiring, which we believe is fundamental to explaining this
similarity. The class of exact semirings turns out to include many other
important examples of both rings (proper quotients of principal ideal domains,
matrix rings and finite group rings over these and over fields), and semirings
(the Boolean semiring, generalisations of the tropical semiring, matrix
semirings and group semirings over these).Comment: 17 pages; fixed typos, clarified a few points, changed notation in
Example 6.
Energía eólica: dimensionamiento de un parque eólico offshore flotante
En un mercado estancado por la limitación en las profundidades del fondo marino, la energía eólica marina ha conseguido romper esta barrera mediante los sistemas de plataformas flotantes. Con esto, la explotación de dicha energía renovable en el mar aumentará de forma notable, siendo referente en la producción mediante energías limpias. En este proyecto se dimensiona un parque eólico offshore flotante en la costa de Galicia
Fiabilidad de la red Primaria de Abastecimiento en el Ambito del Gran Bilbao
El suministro de agua continuo y de calidad es fundamental para la vida cotidiana de las personas, la salud pública y el desarrollo socioeconómico en la región del Gran Bilbao, sin embargo, una rotura en un canal procedente de una fuente de abastecimiento podría ocasionar la carencia de agua para abastecer a la población. Por esta razón, en el presente proyecto se estudia la fiabilidad de la red primaria mediante la simulación del modelo del sistema del software EPANET, con el fin de proponer las medidas de contingencia necesarias para cubrir la necesidad de abastecer agua en caso de emergencias
Aligning Manufacturing Strategies with Complexity Factors in the Aerospace Supply Chain
Aerofirm is a large and vertically-integrated manufacturer providing strong and light materials mainly for commercial aerospace, but also for space, defense and industrial application. They face complexity from varying customer needs, a vast product range and a large network. Complexity at Aerofirm also arises from unsynchronized processes, this paper focuses on aligning the manufacturing strategy process. The approach proposed is to first calculate suitable strategy based on: forecast accuracy, volume variability, relative volume and supply chain depth. The results were then reviewed by key personnel to refine them based on qualitative knowledge, showing a mix of manufacturing strategies is essential
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