8,105 research outputs found
Using Generic Summarization to Improve Music Information Retrieval Tasks
In order to satisfy processing time constraints, many MIR tasks process only
a segment of the whole music signal. This practice may lead to decreasing
performance, since the most important information for the tasks may not be in
those processed segments. In this paper, we leverage generic summarization
algorithms, previously applied to text and speech summarization, to summarize
items in music datasets. These algorithms build summaries, that are both
concise and diverse, by selecting appropriate segments from the input signal
which makes them good candidates to summarize music as well. We evaluate the
summarization process on binary and multiclass music genre classification
tasks, by comparing the performance obtained using summarized datasets against
the performances obtained using continuous segments (which is the traditional
method used for addressing the previously mentioned time constraints) and full
songs of the same original dataset. We show that GRASSHOPPER, LexRank, LSA,
MMR, and a Support Sets-based Centrality model improve classification
performance when compared to selected 30-second baselines. We also show that
summarized datasets lead to a classification performance whose difference is
not statistically significant from using full songs. Furthermore, we make an
argument stating the advantages of sharing summarized datasets for future MIR
research.Comment: 24 pages, 10 tables; Submitted to IEEE/ACM Transactions on Audio,
Speech and Language Processin
On the Application of Generic Summarization Algorithms to Music
Several generic summarization algorithms were developed in the past and
successfully applied in fields such as text and speech summarization. In this
paper, we review and apply these algorithms to music. To evaluate this
summarization's performance, we adopt an extrinsic approach: we compare a Fado
Genre Classifier's performance using truncated contiguous clips against the
summaries extracted with those algorithms on 2 different datasets. We show that
Maximal Marginal Relevance (MMR), LexRank and Latent Semantic Analysis (LSA)
all improve classification performance in both datasets used for testing.Comment: 12 pages, 1 table; Submitted to IEEE Signal Processing Letter
Deep Dialog Act Recognition using Multiple Token, Segment, and Context Information Representations
Dialog act (DA) recognition is a task that has been widely explored over the
years. Recently, most approaches to the task explored different DNN
architectures to combine the representations of the words in a segment and
generate a segment representation that provides cues for intention. In this
study, we explore means to generate more informative segment representations,
not only by exploring different network architectures, but also by considering
different token representations, not only at the word level, but also at the
character and functional levels. At the word level, in addition to the commonly
used uncontextualized embeddings, we explore the use of contextualized
representations, which provide information concerning word sense and segment
structure. Character-level tokenization is important to capture
intention-related morphological aspects that cannot be captured at the word
level. Finally, the functional level provides an abstraction from words, which
shifts the focus to the structure of the segment. We also explore approaches to
enrich the segment representation with context information from the history of
the dialog, both in terms of the classifications of the surrounding segments
and the turn-taking history. This kind of information has already been proved
important for the disambiguation of DAs in previous studies. Nevertheless, we
are able to capture additional information by considering a summary of the
dialog history and a wider turn-taking context. By combining the best
approaches at each step, we achieve results that surpass the previous
state-of-the-art on generic DA recognition on both SwDA and MRDA, two of the
most widely explored corpora for the task. Furthermore, by considering both
past and future context, simulating annotation scenario, our approach achieves
a performance similar to that of a human annotator on SwDA and surpasses it on
MRDA.Comment: 38 pages, 7 figures, 9 tables, submitted to JAI
Investment valuation of a project in a winery : the case of Sociedade Agrícola de Vale de Fornos
Mestrado em FinançasA produção e consumo de vinho no Mundo tem sido bastante regular. Em Portugal, o sector vitivinícola tem uma longa tradição, estando sempre presente na vida dos portugueses, que são os maiores consumidores de vinho per capita do Mundo. Contudo, a tradição não impediu que o nível de interesse e a exigência do consumidor de vinho aumentasse ao longo do tempo. Essa exigência, juntamente com a dinamização das exportações de vinho, com o forte apoio do Estado Português mediante a atribuição de subsídios para requalificação das explorações agrícolas, potenciaram o aparecimento de novos players de mercado de maior dimensão e, sobretudo, de novos vinhos de qualidade mais elevada. Actualmente, Portugal é um dos maiores produtores e consumidores de vinho em volume do Mundo, sendo ainda o sexto país onde a exportação deste produto tem maior valor acrescentado.
Baseado no caso específico de uma empresa vitivinícola nacional, que tem como core business a produção, engarrafamento, comercialização e distribuição de vinho em Portugal, o presente trabalho tem os seguintes objectivos: (1) enquadrar e identificar o cenário competitivo da empresa e (2) efectuar uma análise de viabilidade de um projecto de investimento com base no cenário anteriormente identificado, utilizando como método de avaliação os Discounted Cash Flows. Serão usados os modelos FCFF, APV e FCFE de forma a apurar o valor actualizado líquido do projecto de investimento e será demonstrado que, mantendo um rácio debt-to-equity constante, o resultado da avaliação é igual usando qualquer dos modelos.Wine production and consumption in the world has been pretty regular. In Portugal, the wine production sector has a long tradition, being always present in the lives of Portuguese people who are the biggest wine consumers per capita in the world. However, tradition has not avoided an increase, over the time, of the level of interest and demand of the wine consumer. That demand, together with the revitalization of the wine exports, with the strong support of the Portuguese Government that has given subsidies for the requalification of wine explorations, has allowed the emergence of new and bigger market players, and above all, of new wines of higher quality. Currently, Portugal is one of the biggest wine producers and consumers in the world. And it is the sixth country in which the exportation of that product has a bigger added value.
Based on the specific case of a national winery company, that has as core business the production, bottling, trading and distribution of wine in Portugal, this work as the following goals: (1) put in context and identify the competitive scenario of the company and (2) make an analysis of the viability of an investment project based on the previously identified scenario, using the Discounted Cash Flows as an evaluation method. Will be used the FCFF, APV and FCFE models to obtain the net present value of the project investment, aiming to proof that, if we maintain a constant debt-to-equity, the result of the evaluation is the same.info:eu-repo/semantics/publishedVersio
Money multiplier in a fixed exchange regime framework
Mestrado em Economia Monetária e FinanceiraEste estudo apresenta uma nova abordagem empírica sobre o processo de multiplicador monetário, usando dados monetários mensais de Angola desde janeiro de 2012 até junho de 2018. O uso de um modelo ARDL permite testar a relação de longo prazo tanto do multiplicador monetário como da relação entre as reservas e os depósitos e considerar os ajustes de curto prazo a choques monetários. A análise foca principalmente o nível de concentração do sistema bancário, o grau de liquidez do passivo dos bancos e a taxa de juros como determinantes dos índices de longo prazo. Outros factores específicos do país, como o spread da taxa de câmbio e o rácio de incumprimentos, foram incluídos na análise, para considerar os desafios macroeconómicos de Angola. Concluiu-se que, de acordo com a teoria monetária, tanto a taxa de juros quanto o nível de concentração do sistema bancário afetam os índices de longo prazo. No entanto, a não significância estatística da liquidez das responsabilidades dos bancos permite uma recomendação política para a política monetária de Angola.This study provides a new empirical approach about the money multiplier process, using monthly monetary data from Angola since January 2012 until June 2018. The use of an ARDL model allows to test the long run relationship of both the money multiplier and the reserve to deposit ratio and consider the short-term adjustments from monetary shocks. The analysis focuses mainly on the level of concentration of the banking system, the degree of liquidity of banks' liabilities and the interest rate as determinants of the long-term ratios. Other country specific factors such as the foreign exchange rate spread and the non-performing loans ratio have been included to the analysis, to consider Angola's macroeconomic challenges. It was concluded that according to monetary theory, both the interest rate and the level of concentration of the banking system affect the long-term ratios. However, the non-statistical significance of banks' liabilities liquidity opens a policy recommendation for Angola's monetary policy.info:eu-repo/semantics/publishedVersio
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