ABC with a UNIX Flavor

abc is a simple, yet powerful, textual musical notation. This paper presents abc::dt, a rule-based domain-specific language (Perl embedded), designed to simplify the creation of abc processing tools. Inspired by the Unix philosophy, those tools intend to be simple and compositional in a Unix filters\u27 way. From abc::dt\u27s rules we obtain an abc processing tool whose main algorithm follows a traditional compiler architecture, thus consisting of three stages: 1) abc parser (based on abcmtops\u27 parser), 2) abc semantic transformation (associated with abc attributes), 3) output generation (either a user defined or system provided abc generator)

Fuel and operational hedging : evidence from the airline industry

A indústria da aviação é, hoje em dia, caraterizada por uma intensa competição global entre companhias aéreas. Os custos com combustível representam uma parte substancial das despesas operacionais e estão sempre sujeitos à volatilidade do mercado. Tanto a cobertura de risco financeiro como operacional estão ao dispor das companhias aéreas para contrariar a volatilidade e reduzir os custos em combustível. Sendo um dos poucos estudos a incluir companhias aéreas da Europa e da Ásia, esta investigação foca-se em 43 companhias ao longo do período 2007-2017 e conclui que as transportadoras aéreas Europeias têm menor exposição ao risco do preço do combustível, do que as companhias Asiáticas ou Norte-Americanas. Também é realizada uma comparação entre tipos de companhias e é possível concluir que a exposição média ao preço do querosene é maior em companhias-bandeira do que nas de baixo custo. Pensamos que este será o primeiro estudo global a incluir três medidas de cobertura de risco operacional, sendo estes a diversidade da frota, a eficiência de combustível, e a utilização de aviões em leasing operacional. Treanor, Carter, Rogers, & Simkins (2013) estudaram estas medidas mas apenas em companhias Norte-Americanas. Usando modelos de efeitos-fixos, os nossos resultados sugerem que a cobertura do risco financeiro acaba por aumentar a exposição. Adicionalmente, as nossas evidências apontam para uma rejeição da hipótese de que a cobertura de risco operacional leva a uma diminuição da exposição ao risco do preço do querosene, em todas as nossas três proxies.The airline industry is nowadays characterized by an intense competition among carriers around the globe. Jet fuel costs represent a substantial part of airlines’ operating expenses and are always subject to the market volatility. Both financial and operational hedging are at the disposal of airlines to offset the volatility and smooth these expenses across the years. Being one of the few studies to include airlines from Europe and Asia, this research focuses in 43 airlines over the period 2007-2017 and finds that European carriers are less exposed to fuel price than Asian or North American airlines. We also test for types of carriers and find evidence that the average fuel exposure is higher on premium airlines, when comparing to low-cost carriers. To our knowledge, this is the first study to include three measures of operational hedging on a global sample of airlines, namely fleet diversity, fuel-efficiency and operating leased aircrafts. Treanor, Carter, Rogers, & Simkins (2013) studied these but only on a sample of North American airlines. Using fixed-effects’ models, our results suggest that financial hedging increases fuel risk exposure. Furthermore, our results lead to a rejection of the hypothesis that operational hedging decreases airlines’ exposure, on all three proxies we consider

INFOVIS: A COLLABORATIVE SYSTEM FOR VISUALIZING REPOSITORIES

[EN] This article aims to conceptualize a new communicative paradigm applied to academic scientific repositories. The publication and the querying of articles, papers, journals, books and other documents, are an integral part of the research process. However, the querying and information visualization process in a scientific academic repository, often proves to be inefficient, and a hard task, because the wide range of results hardly fits in the user’s specific subject. In this sense, this paper highlights a problem that emerges from the user’s relationship with an academic repository of scientific information. In particular, a problem that is related to the “object content” (results) that best suits the interests/user’s specific subject. However, if we equate that this information is accessed by a significant number of users with a specific interest in a topic, and in the course of their research they handle a significant amount of information, it is then possible to consider the existence of a hierarchical and relational structure of evidences, that emerges from the relationship established between the various users and their specific interests and the querying performed. Therefore, it is fundamental to consider the user’s experience and the leading role that it could represent in filtering information. The Information Visualization (InfoVis) techniques directed to knowledge networks also constitutes a fundamental approach. In this sense, this paper presents a brief analysis around major reference projects, which although based in the metric of article citations (impact factor), the primary goal lies in the visualization of an extensive citation structure and the relations established between the different scientific fields. However, based on the modus operandi of these visualization interfaces, the main objective of this paper is to propose a new approach, where the filtering and the visualization of information is based in the user’s experience instead of the usual citation “object” centered approach.[ES] Este artículo pretende conceptualizar un nuevo paradigma comunicativo aplicado a repositorios científicos académicos. La publicación de artículos y consulta como revistas, libros y otros documentos, son una parte integral del proceso de investigación. La búsqueda de la información en repositorios académicos, a menudo resulta ser ineficiente debido a la amplia gama de resultados obtenidos, que difícilmente se enmarcan en el campo/temática específica del usuario. En este sentido, se evidencia una problemática que parte de la relación del usuario con el repositorio académico de la información científica. La relación de la información encontrada no siempre es la adecuada para los intereses específicos que el usuario pretende encontrar. Siendo que esta información se consulta por un gran número de usuarios con un interés específico en un determinado tema, y éstos en el curso de la búsqueda, manejan una cantidad significativa de documentos. Sabemos que existe una estructura relacional y jerárquica que resulta de la interacción entre los diferentes usuarios, sus intereses específicos y la búsqueda efectuada. De esta manera, es fundamental tener en cuenta la experiencia del usuario y el papel preponderante que éste podría representar en la filtración de la información. Las técnicas InfoVis desarrolladas para redes de conocimiento, constituyen una hipótesis de partida para el problema planteado. Este artículo presenta un análisis breve en torno a los principales proyectos de referencia, que a pesar de estar basados en un análisis de citas de artículos fundados en el factor de impacto, presentan como característica principal, la visualización de patrones entorno a una amplia estructura de citaciones y relaciones entre las distintas áreas. Con base en el modus operandi de estas interfaces de visualización, este artículo se propone un nuevo enfoque, para visualizar la información, basada en la experiencia del usuario en lugar del usual enfoque centrado en “objeto” de la citación.Azevedo, B.; Tortosa Cuesta, R. (2015). INFOVIS: A COLLABORATIVE SYSTEM FOR VISUALIZING REPOSITORIES. En Actas Segundo Congreso Internacional Arte Ciencia Ciudad ACC2015. Editorial Universitat Politècnica de València. 170-179. http://hdl.handle.net/10251/96311OCS17017

Hydrodynamic Modelling of Ria Formosa (South Coast of Portugal) with EcoDynamo

In this work a hydrodynamic model of Ria Formosa (South of Portugal) is presented. Ria Formosa is a large (c.a. 100 km2) mesotidal lagunary system with large intertidal areas and several conflicting uses, such as fisheries, aquaculture, tourism and nature conservation. This coastal ecosystem is a natural park where several management plans and administrative responsibilities overlap. The work presented here is part of a coupled hydrodynamicbiogeochemical model that includes pelagic and benthic processes and variables. It is a two-dimensional vertically integrated hydrodynamic model, based on a finite differences grid with a 100 m spatial step and a semi-implicit resolution scheme. It is forced by tide level changes at the sea boundary and river flows at the land boundary. The model includes a wetdrying scheme to account for the dynamics of the large intertidal areas. The purposes of this work are to: (i) describe the model; (ii) present its calibration and validation against field data; (iii) use the model to analyse circulation patterns and estimate the water residence time and (iv) analyse the dispersion of effluents rejected by the Waste Water Treatment Plants located in the lagoon.DITTY (Development of an information technology tool for the management of Southern European lagoons under the influence of river-basin runoff) (EESD Project EVK3-CT-2002-00084

ABC with a UNIX flavor

ABC is a simple, yet powerful, textual musical notation. This paper presents ABC::DT, a rule-based domain-specific language (Perl embedded), designed to simplify the creation of ABC processing tools. Inspired by the Unix philosophy, those tools intend to be simple and compositional in a Unix filters' way. From ABC::DT's rules we obtain an ABC processing tool whose main algorithm follows a traditional compiler architecture, thus consisting of three stages: 1) ABC parser (based on abcm2ps' parser), 2) ABC semantic transformation (associated with ABC attributes), 3) output generation (either a user defined or system provided ABC generator).(undefined)info:eu-repo/semantics/publishedVersio

Design for digital repositories: conceptualizing new communicative paradigms to filter and visualize scientific contents

[EN] This article aims to conceptualize a new communicative paradigm applied to academic scientific repositories. The publication and the querying of articles, papers, journals, books and other documents, are an integral part of the research process. However, the querying and information visualization process in a scientific academic repository, often proves to be inefficient, because the wide range of results hardly fits in the user¿s specific subject. In this sense, it is presented a brief analysis around major reference projects, which although based in the metric of article citations (impact factor), the primary goal lies in the visualization of an extensive citation structure and the relations established between the different scientific fields. Based on the modus operandi of these visualization interfaces, the main objective of this paper is to propose a new approach, where the filtering and the visualization of information is based in the user¿s experience instead of the usual citation "object" centered approach.[ES] El artículo propone un nuevo paradigma comunicactivo aplicado a repositorios científicos académicos. La publicación de artículos y consulta como revistas, libros y otros documentos, son una parte integral del proceso de investigación. La búsqueda de la información en repositorios académicos, a menudo resulta ser ineficiente debido a la amplia gama de resultados obtenidos. En este sentido, se realiza un estudio breve en torno a los principales proyectos de referencia, que a pesar de estar basados en un análisis de citas de artículos fijados en el factor de impacto, presentan como característica principal la visualización de patrones entorno a una amplia estructura de citaciones y relaciones entre las distintas áreas. A partir del mudus operandi de estas interfaces de visualización, el artículo plantea una nueva orientación fundada en la experiencia del usuario en lugar del habitual enfoque centrado en "objeto" de la citaciónAzevedo-Monteiro, BM.; Tortosa-Cuesta, R. (2016). Design for digital repositories: conceptualizing new communicative paradigms to filter and visualize scientific contents. AusArt. 4(1):237-250. doi:10.1387/ausart.16714S2372504

Co-Occurrence of Design Patterns and Bad Smells in Software Systems: An Exploratory Study

A design pattern is a general reusable solution to a recurring problem in software design. Bad smells are symptoms that may indicate something wrong in the system design or code. Therefore, design patterns and bad smells represent antagonistic structures. They are subject of recurring research and typically appear in software systems. Although design patterns represent good design, their use is often inadequate because their implementation is not always trivial or they may be unnecessarily employed. The inadequate use of design patterns may lead to a bad smell. Therefore, this paper performs an exploratory study in order to identify instances of co-occurrences of design patterns and bad smells. This study is performed over five systems and discovers some co-occurrences between design patterns and bad smells. For instance, we observed the co-occurrences of Command with God Class and Template Method with Duplicated Code. The results of this study make it possible to understand in which situations design patterns are misused or overused and establish guidelines for their better use