102 research outputs found

    Information Processing of Foreign Exchange News: Extending the Overshooting Model to Include Qualitative Information from News Sentiment

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    In a globalized world, the volume of international trade is based on both import and export prices, thereby making a country\u27s economy highly dependent on exchange rates. In order to study exchange rate movements, one frequently exploits the so-called Dornbusch overshooting model. However, the model is controversial from a theoretical point of view: it presupposes the processing of information, though this is not directly reflected by the underlying variables. As a remedy, this paper investigates a potential cognitive bias by including textual news content, thus adjusting for information dissemination. As such, we perform a multivariate analysis to compare the classical overshooting model with an extended variant that includes news sentiment. Our results show that news has a substantial explanatory power of 11% of the exchange rate forecasting error variance. In addition, we also find statistical evidence that a shock in news sentiment may lead to overshooting

    Is News Sentiment More Than Just Noise?

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    Big Data analytics has recently fostered significant research on the influence of news sentiment in finance. This paper thus examines the effect of news sentiment on crude oil prices for different investor types according to the noise trader approach. The noise trader approach assumes the presence of informed and uninformed investors. Informed investors possess a perfect information horizon, whereas uninformed investors trade upon noise signals, such as sentiment. Methodologically, we decompose the crude oil price with a Kalman filter into a Kalman-smoothed, fundamental price component and a noise residual. We then regress news sentiment on both decomposed oil price components. Our findings suggest that news sentiment not only has a significant positive effect on the noise residual (as suggested by the noise trader approach), but also on the fundamental price. Thus, we find empirical evidence contradicting the noise trader model, which assumes that only uninformed investors trade on sentiment

    Sentiment Analysis in Digital Spaces: An Overview of Reviews

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    Sentiment analysis (SA) is commonly applied to digital textual data, revealing insight into opinions and feelings. Many systematic reviews have summarized existing work, but often overlook discussions of validity and scientific practices. Here, we present an overview of reviews, synthesizing 38 systematic reviews, containing 2,275 primary studies. We devise a bespoke quality assessment framework designed to assess the rigor and quality of systematic review methodologies and reporting standards. Our findings show diverse applications and methods, limited reporting rigor, and challenges over time. We discuss how future research and practitioners can address these issues and highlight their importance across numerous applications.Comment: 44 pages, 4 figures, 6 tables, 3 appendice

    Analyzing, enhancing, optimizing and applying dependency analysis

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    Tesis inédita de la Universidad Complutense de Madrid, Facultad de Informática, Departamento de Ingeniería del Software e Inteligencia Artificial, leída el 19/12/2012Los analizadores de dependencias estadísticos han sido mejorados en gran medida durante los últimos años. Esto ha sido posible gracias a los sistemas basados en aprendizaje automático que muestran una gran precisión. Estos sistemas permiten la generación de parsers para idiomas en los que se disponga de un corpus adecuado sin causar, para ello, un gran esfuerzo en el usuario final. MaltParser es uno de estos sistemas. En esta tesis hemos usado sistemas del estado del arte, para mostrar una serie de contribuciones completamente relacionadas con el procesamiento de lenguaje natural (PLN) y análisis de dependencias: (i) Estudio del problema del análisis de dependencias demostrando la homogeneidad en la precisión y mostrando contribuciones interesantes sobre la longitud de las frases, el tamaño de los corpora de entrenamiento y como evaluamos los parsers. (ii) Hemos estudiado además algunas maneras de mejorar la precisión modificando el flujo de análisis de dos maneras distintas, analizando algunos segmentos de las frases de manera separada, y modificando el comportamiento interno de los algoritmos de parsing. (iii) Hemos investigado la selección automática de atributos para aprendizaje máquina para analizadores de dependencias basados en transiciones que consideramos un importante problema y algo que realmente es necesario resolver dado el estado de la cuestión, ya que además puede servir para resolver de mejor manera tareas relacionadas con el análisis de dependencias. (iv) Finalmente, hemos aplicado el análisis de dependencias para resolver algunos problemas, hoy en día importantes, para el procesamiento de lenguage natural (PLN) como son la simplificación de textos o la inferencia del alcance de señales de negación. Por último, añadir que el conocimiento adquirido en la realización de esta tesis puede usarse para implementar aplicaciones basadas en análisis de dependencias más robustas en PLN o en otras áreas relacionadas, como se demuestra a lo largo de la tesis. [ABSTRACT] Statistical dependency parsing accuracy has been improved substantially during the last years. One of the main reasons is the inclusion of data- driven (or machine learning) based methods. Machine learning allows the development of parsers for every language that has an adequate training corpus without requiring a great effort. MaltParser is one of such systems. In the present thesis we have used state of the art systems (mainly Malt- Parser), to show some contributions in four different areas inherently related to natural language processing (NLP) and dependency parsing: (i) We stu- died the parsing problem demonstrating the homogeneity of the performance and showing interesting contributions about sentence length, corpora size and how we normally evaluate the parsers. (ii) We have also tried some ways of improving the parsing accuracy by modifying the flow of analysis, parsing some segments of the sentences separately by finally constructing a parsing combination problem. We also studied the modification of the inter- nal behavior of the parsers focusing on the root of dependency structures, which is an important part of what a dependency parser parses and worth studying. (iii) We have researched automatic feature selection and parsing optimization for transition based parsers which we consider an important problem and something that definitely needs to be done in dependency par- sing in order to solve parsing problems in a more successful way. And (iv) we have applied syntactic dependency structures and dependency parsing to solve some Natural Language Processing (NLP) problems such as text simplification and inferring the scope of negation cues. Furthermore, the knowledge acquired when developing this thesis could be used to implement more robust dependency parsing–based applications in different NLP (or related) areas, as we demonstrate in the present thesis.Depto. de Ingeniería de Software e Inteligencia Artificial (ISIA)Fac. de InformáticaTRUEunpu
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