Leveraging Final Degree Projects for Open Source Software Contributions

(1) Background: final year students of computer science engineering degrees must carry out a final degree project (FDP) in order to graduate. Students’ contributions to improve open source software (OSS) through FDPs can offer multiple benefits and challenges, both for the students, the instructors and for the project itself. This work reports on a practical experience developed by four students contributing to mature OSS projects during their FDPs, detailing how they addressed the multiple challenges involved, both from the students and teachers perspective. (2) Methods: we followed the work of four students contributing to two established OSS projects for two academic years and analyzed their work on GitHub and their responses to a survey. (3) Results: we obtained a set of specific recommendations for future practitioners and detailed a list of benefits achieved by steering FDP towards OSS contributions, for students, teachers and the OSS projects. (4) Conclusions: we find out that FDPs oriented towards enhancing OSS projects can introduce students into real-world, practical examples of software engineering principles, give them a boost in their confidence about their technical and communication skills and help them build a portfolio of contributions to daily used worldwide open source applications

A systematic mapping study on integration proposals of the personas technique in agile methodologies

Agile development processes are increasing their consideration of usability by integrating various user‐centered design techniques throughout development. One such technique is Personas, which proposes the creation of fictitious users with real preferences to drive application design. Since applying this technique conflicts with the time constraints of agile development, Personas has been adapted over the years. Our objective is to determine the adoption level and type of integration, as well as to propose improvements to the Personas technique for agile development. A systematic mapping study was performed, retrieving 28 articles grouped by agile methodology type. We found some common integration strategies regardless of the specific agile approach, along with some frequent problems, mainly related to Persona modelling and context representation. Based on these limitations, we propose an adaptation to the technique in order to reduce the creation time for a preliminary persona. The number of publications dealing with Personas and agile development is increasing, which reveals a growing interest in the application of this technique to develop usable agile softwareThis research was funded by the Spanish Ministry of Science, Innovation and Universities research grant PGC2018-097265-B-I00, MASSIVE project (RTI2018-095255-B-I00) and by EIT-Health, grant number 19091 (POSITIVE project). This research was also supported by the Madrid Region R&D programme (project FORTE, P2018/TCS-4314

Data Management in Microservices: State of the Practice, Challenges, and Research Directions

We are recently witnessing an increased adoption of microservice architectures by the industry for achieving scalability by functional decomposition, fault-tolerance by deployment of small and independent services, and polyglot persistence by the adoption of different database technologies specific to the needs of each service. Despite the accelerating industrial adoption and the extensive research on microservices, there is a lack of thorough investigation on the state of the practice and the major challenges faced by practitioners with regard to data management. To bridge this gap, this paper presents a detailed investigation of data management in microservices. Our exploratory study is based on the following methodology: we conducted a systematic literature review of articles reporting the adoption of microservices in industry, where more than 300 articles were filtered down to 11 representative studies; we analyzed a set of 9 popular open-source microservice-based applications, selected out of more than 20 open-source projects; furthermore, to strengthen our evidence, we conducted an online survey that we then used to cross-validate the findings of the previous steps with the perceptions and experiences of over 120 practitioners and researchers. Through this process, we were able to categorize the state of practice and reveal several principled challenges that cannot be solved by software engineering practices, but rather need system-level support to alleviate the burden of practitioners. Based on the observations we also identified a series of research directions to achieve this goal. Fundamentally, novel database systems and data management tools that support isolation for microservices, which include fault isolation, performance isolation, data ownership, and independent schema evolution across microservices must be built to address the needs of this growing architectural style

Opinion Mining for Software Development: A Systematic Literature Review

Opinion mining, sometimes referred to as sentiment analysis, has gained increasing attention in software engineering (SE) studies. SE researchers have applied opinion mining techniques in various contexts, such as identifying developers’ emotions expressed in code comments and extracting users’ critics toward mobile apps. Given the large amount of relevant studies available, it can take considerable time for researchers and developers to figure out which approaches they can adopt in their own studies and what perils these approaches entail. We conducted a systematic literature review involving 185 papers. More specifically, we present 1) well-defined categories of opinion mining-related software development activities, 2) available opinion mining approaches, whether they are evaluated when adopted in other studies, and how their performance is compared, 3) available datasets for performance evaluation and tool customization, and 4) concerns or limitations SE researchers might need to take into account when applying/customizing these opinion mining techniques. The results of our study serve as references to choose suitable opinion mining tools for software development activities, and provide critical insights for the further development of opinion mining techniques in the SE domain

Brazilian extreme wind climate

Uma característica importante da otimização dos processos de projeto em engenharia civil é a demanda pelo aperfeiçoamento da precisão das estimativas das cargas de projeto. As cargas de projeto devidas ao vento são baseadas em análises de registros de dados climatológicos para as quais modelos estatísticos são desenvolvidos. Tais modelos propõem níveis de carga com certas probabilidades de ocorrência durante um determinado período de retorno, ou intervalo médio de recorrência. Desde 1988, a NBR 6123: Forças devidas ao vento em edificações, a norma brasileira de cargas de vento, tem equilibrado a competição das necessidades de segurança e de conforto do usuário contra os custos de construção da cada vez mais alta silhueta urbana da nação. O mapa de isopletas do parâmetro de velocidade básica regional é o ponto inicial para todos os cálculos de cargas de projeto devidas ao vento na maior nação da América do Sul, com velocidades de vento regionais derivadas da distribuição de Fréchet, utilizando as máximas velocidades de rajada anuais equivalentes de 1950 a 1975 observadas, em aeródromos brasileiros. Além do potencial de utilizar mais de 40 anos de novos dados, incluindo dados da rede de observação automatizada do INMET, avanços nas comunidades científicas de engenharia do vento, meteorologia e estatística permitem o desenvolvimento de modelos climáticos mais detalhados e robustos. Há, também, uma crescente necessidade de separar os eventos de tempestades de vento em eventos não- sinóticos e sinóticos, devido às suas diferentes características. O estudo produz modelos climáticos regionais de ventos extremos atualizados em todo o Brasil, para serem usados tanto em casos de estados limite último e de serviço do projeto. Dados meteorológicos das duas maiores redes meteorológicas brasileiras, adquiridos de diversas fontes, foram utilizados, mas apenas após um exame completo da qualidade de cada fonte. Investigações foram feitas com relação a metadados históricos e atuais (altura, localização, tipo de anemômetro) de cada estação, com resultados variados. Correções de velocidades do vento foram feitas para terreno e altura, onde necessário. Algoritmos robustos para a separação de velocidades de vento pico não-sinóticas, sinóticas e duvidosas foram desenvolvidos e aplicados a uma série histórica de dados de 692 estações meteorológicas de superfície para gerar conjuntos de valores extremos para uma análise de valor extremo com Método de Tempestades Independentes modificado. Constatou-se que os ventos não-sinóticos são dominantes na maioria do Brasil para todos os períodos de retorno. Parâmetros meteorológicos relacionados a ventos extremos não-sinóticos e sinóticos foram mapeados por todo o país. Um mapa de isopletas de velocidades básicas do vento foi proposto para uma versão atualizada da NBR 6123, acompanhado dos fatores probabilísticos atualizados para uma DGVE Tipo I – Distribuição de Gumbel. Recomendações chave incluem a necessidade de maiores investigações sobre as características de ventos não-sinóticos no Brasil e o melhoramento dos registros de metadados por parte das organizações meteorológicas.A critical feature of the continual optimisation of civil engineering design processes is the demand to improve accuracy of design load estimations. Design wind loads are based on analyses of recorded historical meteorological data for which statistical models are developed. Such models propose load levels of certain probabilities of occurrence over a particular return period, or mean recurrence interval. Since 1988, NBR 6123: Forças devidas ao vento em edificações, Brazil’s wind loading code, has balanced the competing needs of public safety and tenant comfort against construction costs of the nation’s ever-growing skyline. The isopleth map of the regional basic velocity parameter is the basis for all wind design load calculations in South America’s largest nation, with regional wind speeds derived from the Fréchet distribution of annual maxima equivalent gust speeds from 1950 to 1975 observed at Brazilian aerodromes. Besides the potential to utilise more than 40 years of new data, including data from INMET’s automated observing network, advances across the scientific communities of wind engineering, meteorology and statistics allow for the development of more detailed and robust climatic models. There is also a growing need to separate wind storm events into non-synoptic and synoptic events due to their different characteristics. The study produces updated regional extreme wind climate models across Brazil to be used for both serviceability and ultimate design load cases. Meteorological data from the two Brazilian meteorological networks acquired from several sources were utilised, but only after thorough examination of the quality of each source. Investigations were made regarding historical and current metadata (height, location, anemometer type) of each station with mixed success. Corrections to wind speeds were made for terrain and height where necessary. Robust algorithms for the separation of non-synoptic, synoptic and suspicious peak wind speeds were developed and applied to time-series data from 692 surface weather stations to generate sets of extreme values for a modified Method of Independent Storms extreme value analysis. Non-synoptic winds were found to dominant the majority of Brazil for all return periods. Meteorological parameters relating to non-synoptic and synoptic extreme winds were mapped across the country. An isopleth map of basic wind speeds was proposed for an updated version of NBR 6123, with accompanying updated probabilistic factors for a GEVD Type I – Gumbel distribution. Key recommendations include the need for further investigations into non-synoptic wind characteristics in Brazil and the improvement of metadata records by meteorological organisations