Automatic creation of stock market lexicons for sentiment analysis using StockTwits data

Sentiment analysis has been increasingly applied to the stock market domain. In particular, investor sentiment indicators can be used to model and predict stock market variables. In this context, the quality of the sentiment analysis is highly dependent of the opinion lexicon adopted. However, there is a lack of lexicons adjusted to microblogging stock market data. In this work, we propose an automatic procedure for the creation of such lexicon by exploring a large set of labeled messages from StockTwits, a popular financial microblogging service, and using four statistical measures: adaptations of the known TF-IDF, Information Gain, Class Percentage, and a newly proposed Weighted Class Probability. The obtained lexicons are competitive when compared with a set of six reference lexicons. Moreover, we verified that it is beneficial to use continuous sentiment scores instead of sentiment labels.We wish to thank StockTwits for kindly providing their data. This work has been supported by FCT - Fundacao para a Ciencia e Tecnologia within the Project Scope: PEst-OE/EEI/UI0319/2014

On the predictability of stock market behavior using StockTwits sentiment and posting volume

Series title : Lecture notes in computer science, vol. 8154Inthisstudy,weexploreddatafromStockTwits,amicroblog- ging platform exclusively dedicated to the stock market. We produced several indicators and analyzed their value when predicting three market variables: returns, volatility and trading volume. For six major stocks, we measured posting volume and sentiment indicators. We advance on the previous studies on this subject by considering a large time period, using a robust forecasting exercise and performing a statistical test of forecasting ability. In contrast with previous studies, we find no evidence of return predictability using sentiment indicators, and of information content of posting volume for forecasting volatility. However, there is ev- idence that posting volume can improve the forecasts of trading volume, which is useful for measuring stock liquidity (e.g. assets easily sold).This work is funded by FEDER, through the program COMPETE and the Portuguese Foundation for Science and Technology (FCT), within the project FCOMP-01-0124-FEDER-022674. The also authors wish to thank StockTwits for kindly providing their data

Some experiments on modeling stock market behavior using investor sentiment analysis and posting volume from twitter

The analysis of microblogging data related with stock mar- kets can reveal relevant new signals of investor sentiment and attention. It may also provide sentiment and attention indicators in a more rapid and cost-effective manner than other sources. In this study, we created several indicators using Twitter data and investigated their value when model- ing relevant stock market variables, namely returns, trading volume and volatility. We collected recent data from nine ma jor technological companies. Several sentiment analy- sis methods were explored, by comparing 5 popular lexical resources and two novel lexicons (emoticon based and the merge of all 6 lexicons) and sentiment indicators produced using two strategies (based on daily words and individual tweet classifications). Also, we measured posting volume associated with tweets related to the analyzed companies. While a short time period is considered (32 days), we found scarce evidence that sentiment indicators can explain these stock returns. However, interesting results were obtained when measuring the value of using posting volume for fit- ting trading volume and, in particular, volatility.This work is funded by FEDER, through the program COM- PETE and the Portuguese Foundation for Science and Technology (FCT), within the project FCOMP-01-0124-FEDER- 022674

Communicating through sound in museum exhibitions: unravelling a field of practice

The twentieth century was the stage for several phenomena which have paved the way for museums to start exhibiting sound and to nurture a vivid and increasing interest in its potentialities. The burgeoning of sound recording technologies stands as a milestone in this respect. These have allowed sound to become a physical object and, hence, new understandings and conceptualizations to emerge. In the wake of these developments, the ways in which museum curators look at sound has gone into a huge reconfiguration. The fact that both new museology and museum practice have been turning their attention to and focus on the visitor has similarly accelerated the curators’ interest in sound as a means to build museum exhibitions. One of the latest and most striking instances in this process has been the role of ethnomusicology and sound studies in demonstrating the cultural, social, political, economic and ethical significance of sound thereby stimulating museum’s interest in dealing with sound as a mode to build both individual subjectivities and communities in museum settings. The development of audio technologies and digital and multisensorial technologies (Virtual Reality, Augmented Reality and Mixed Reality) also plays a part in this process. These have the merit to provide ways to deal with the elusiveness of sound when exhibited in museum galleries and to facilitate interactions underpinned by rationales such as experience, embodiment, and emplacement. During at least the last ten years, there has been a boost in the development of sound-based multimodal museum practices. These practices, nonetheless, have yet to be mapped, and their representational and experiential (emotional and sensorial) opportunities to be closely analysed. My thesis strives to start closing this gap by taking two analytical steps. Based on the analysis of 69 sound-based multimodal museum exhibitions staged in Europe and in the United States of America, I provide a five-use framework categorizing sound-based multimodal museum practices into sound as a “lecturing” mode, sound as an artefact, sound as “ambiance”/soundtrack, sound as art, and sound as a mode for crowd-curation. The case-study of sound art The Visitors, it unravels the communicative potential of sound for museums. In detail, the analysis stresses how sound and space comingle to articulate individual subjectivities and a sense of “togetherness.” The scope of the thesis is clearly multidisciplinary, encompassing ethnomusicology, sound studies, museum studies, and social semiotics. Overall, I seek to contribute towards the development of the study of sound in museums to develop and establish as a cohesive research field. I moreover seek to foster a sensory formation shift from a visual epistemology to one that merges the visual and the auditory.O século XX foi palco de vários fenómenos que conduziram a que os museus começassem a expor o som e a demonstrar um interesse crescente pelas suas potencialidades comunicativas. O aparecimento das tecnologias de gravação sonora constitui-se como um momento fundamental neste processo. Ao permitirem que o som se estabeleça enquanto objeto físico, vieram potenciar o aparecimento de novos entendimentos e conceptualizações sobre o som. Na sequência destes acontecimentos, a forma como os curadores de exposições começaram a olhar para o som sofreu grandes alterações. Simultaneamente, o facto de tanto os estudos museológicos como a prática museológica estarem cada vez mais preocupados com o visitante veio também acelerar o interesse dos curadores pelo som como meio para construir exposições museológicas. Os estudos musicais, em particular a etnomusicologia e os estudos de som, tiveram igualmente um papel preponderante: ao demonstrarem o valor cultural, social, político, económico e ético do som vieram claramente estimular o interesse dos curadores em usar o som como material para trabalhar noções de identidade, subjectividade e “comunhão.” É ainda de destacar o papel que o desenvolvimento de tecnologias áudio, digitais e multisensoriais (Realidade Virtual, Realidade Aumentada e Realidade Mista) têm no processo. Ao proporcionarem formas de lidar com a imaterialidade do som quando exposto em galerias, vieram também fomentar interações museológicas sustentadas pela experiência. Nos últimos dez anos, os museus têm, pois, assistido ao incrementar das práticas museológicas multimodais baseadas no som. O mapeamento e a categorização destas práticas, bem como o estudo das suas potencialidades narrativas e experienciais (emocionais e sensoriais), no entanto, está claramente por determinar. A minha tese visa dar início ao colmatar desta lacuna através de dois passos: providenciar uma estrutura classificativa das práticas multimodais baseadas em som com base na análise de 69 exposições que tiveram lugar nos últimos dez anos na Europa e nos Estados Unidos da América. A estrutura compreende as seguintes categorias: som como um modo "discursivo," som como artefacto, som como "ambiance"/banda sonora, som como arte, e som como curadoria partilhada. Simultaneamente, dar início ao desvendar do potencial comunicativo do som para exposições museológicas através do estudo de caso de arte sonora The Visitors. A análise deste estudo de caso veio demonstrar que som, em articulação com o espaço permitem trabalhar noções de identidade, subjetividade, e ainda de “comunhão.” O âmbito da tese é claramente multidisciplinar e engloba a etnomusicologia, os estudos de som, os estudos museológicos e a semiótica social. De uma forma geral, com a minha dissertação procuro contribuir para o desenvolvimento e o estabelecimento do estudo do uso do som nos museus como um campo de investigação multidisciplinar e coeso. Procuro ainda potenciar uma mudança de formação sensorial nos museus, em particular, estimular a passagem de uma epistemologia visual para uma epistemologia simultaneamente visual e auditiva

Popular music exhibitions in Portugal: practices of representation from 2007 to 2013

This thesis focuses on the representation of Popular Music in museums by mapping, analyzing, and characterizing its practices in Portugal at the beginning of the 21st century. Now that museums' ability to shape public discourse is acknowledged, the examination of popular music's discourses in museums is of the utmost importance for Ethnomusicology and Popular Music Studies as well as for Museum Studies. The concept of 'heritage' is at the heart of this processes. The study was designed with the aim of moving the exhibiting of popular music in museums forward through a qualitative inquiry of case studies. Data collection involved surveying pop-rock music exhibitions as a qualitative sampling of popular music exhibitions in Portugal from 2007 to 2013. Two of these exhibitions were selected as case studies: No Tempo do Gira-Discos: Um Percurso pela Produção Fonográfica Portuguesa at the Museu da Música in Lisbon in 2007 (also Faculdade de Letras, 2009), and A Magia do Vinil, a Música que Mudou a Sociedade at the Oficina da Cultura in Almada in 2008 (and several other venues, from 2009 to 2013). Two specific domains were observed: popular music exhibitions as instances of museum practice and museum professionals. The first domain encompasses analyzing the types of objects selected for exhibition; the interactive museum practices fostered by the exhibitions; the concepts and narratives used to address popular music discursively, as well as the interpretative practices they allow. The second domain, focuses museum professionals and curators of popular music exhibitions as members of a group, namely their goals, motivations and perspectives. The theoretical frameworks adopted were drawn from the fields of ethnomusicology, popular music studies, and museum studies. The written materials of the exhibitions were subjected of methods of discourse analysis methods. Semi-structured interviews with curators and museum professional were also conducted and analysed. From the museum studies perspective, the study research suggests that the practice adopted by popular music museums largely matches that of conventional museums. From the ethnomusicological and popular music studies stand point, the two case studies reveal two distinct conceptual worlds: the first exhibition, curated by an academic and an independent researcher, points to a mental configuration where popular music is explained through a framework of genres supported by different musical practices. Moreover, it is industry actors such as decision makers and gatekeepers that govern popular music, which implies that the visitors' romantic conception of the musician is to some extent dismantled; the second exhibition, curated by a record collector and specialist, is based on a more conventional process of the everyday historical speech that encodes a mismatch between “good” and “bad music”. Data generated by a survey shows that only one curator, in fact that of my first case study, has an academic background. The backgrounds of all the others are in some way similar to the curator of the second case study. Therefore, I conclude that the second case study best conveys the current practice of exhibiting Popular Music in Portugal

Third special issue on knowledge discovery and business intelligence

[Excerpt] Expert Systems were proposed in the mid 1970s (Arnott & Pervan, 2014) with the goal of building computerized systems that mimic human behavior to solve real-world tasks. Such systems were based on artificial intelligence (AI) techniques, typically by adopting explicit (human understandable) knowledge, extracted from domain experts (e.g. by using interviews) and that was stored in a knowledge base (Buchanan, 1986).We would like to thank the other KDBI 2015 track (of EPIA) co-organizers, Luis Cavique, Joao Gama and Nuno Marques. Also, we thank the authors, who contributed with their papers, and the reviewers (from the KDBI 2015 program committee and the ES journal). This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT - Fundação para a Ciência e Tecnologia with in the Project Scope: UID/CEC/00319/2013.info:eu-repo/semantics/publishedVersio

Denitrification of a landfill leachate with high nitrate concentration in an anoxic rotating biological contactor

The denitrification performance of a lab-scale anoxic rotating biological contactor (RBC) using landfill leachate with high nitrate concentration was evaluated. Under a carbon to nitrogen ratio (C/N) of 2, the reactor achieved N-NO3 − removal efficiencies above 95% for concentrations up to 100 mg N-NO3 − l−1. The highest observed denitrification rate was 55 mg N-NO3 − l−1 h−1 (15 g N-NO3 − m−2 d−1) at a nitrate concentration of 560 mg N-NO3 − l−1. Although the reactor has revealed a very good performance in terms of denitrification, effluent chemical oxygen demand (COD) concentrations were still high for direct discharge. The results obtained in a subsequent experiment at constant nitrate concentration (220 mg N-NO3 − l−1) and lower C/N ratios (1.2 and 1.5) evidenced that the organic matter present in the leachate was non-biodegradable. A phosphorus concentration of 10 mg P-PO4 3− l−1 promoted autotrophic denitrification, revealing the importance of phosphorus concentration on biological denitrification processes.Susana Cortez and Pilar Teixeira are grateful to Fundacao para a Ciencia e Tecnologia (FCT) for financial support through the grants SFRH/BD/24715/2005 and SFRH/BPD/26803/2006, respectively

Denitrifying activity of activated sludge in suspension and in biofilm

A method based on measuring substrate depletion rate was developed to evaluate the denitrifying activity of activated sludge in suspension and in biofilm form in anoxic serum flasks. The adapted activated sludge inoculum was grown as biofilm in an anoxic rotating biological contactor (RBC). Acetate was used as external carbon source to obtain a carbon to nitrogen ratio (C/N) of 2. The results showed that the specific activity of cells in biofilm form was higher than in planktonic form. The methodology developed can yield useful predictive information and, if used in conjunction with other monitoring devices, could help in maintaining an overall satisfactory denitrifying performance, which is very important in wastewater treatment systems.Susana Cortez and Pilar Teixeira fully acknowledge the financial support of Fundacao para a Ciencia e Tecnologia (FCT) through the grants SFRH/BD/24715/2005 and SFRH/BPD/26803/2006, respectively