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Type-Safe Evolution of Web Services, Campinhos, João, Seco João Costa, and Cunha Jácome , Proceedings of the 2nd International Workshop on Variability and Complexity in Software Design (VACE 2017), a ICSE workshop, Buenos Aires, Argentina, (2017) main.pdf
Evolução Controlada de Arquitecturas de Serviços Web, Campinhos, João, Seco João Costa, and Cunha Jácome , (2016) poster6.1.pdfmain.pdf
SpreadsheetDoc: An Excel Add-in for Documenting Spreadsheets, Canteiro, Diogo, and Cunha Jácome , Proceedings of the 6th National Symposium of Informatics (INForum’15), Covilhã, Portugal, (2015) inforum2015.pdf
Detecting Anomalous Energy Consumption in Android Applications, Carção, Tiago, Couto Marco, Cunha Jácome, Fernandes João Paulo, and Saraiva João , Proceedings of the 18th Brazilian Symposium on Programming Languages, p.77-91, (2014) Abstractsblp14.pdf

The use of powerful mobile devices, like smartphones, tablets and laptops, are changing the way programmers develop software. While in the past the primary goal to optimize software was the run time optimization, nowadays there is a growing awareness of the need to reduce energy consumption. This paper presents a technique and a tool to detect anomalous energy consumption in Android applications, and to relate it directly with the source code of the application. We propose a dynamically calibrated model for energy consumption for the Android ecosystem, and that supports different devices. The model is then used as an API to monitor the application execution: first, we instrument the application source code so that we can relate energy consumption to the application source code; second, we use a statistical approach, based on fault-localization techniques, to localize abnormal energy consumption in the source code.

Modeling the Impact of UAVs in Sustainability, Conejero, José, Brito Isabel, Moreira Ana, Cunha Jácome, and Araújo João , 5th International Workshop on Requirements Engineering for Sustainable Systems (RE4SuSy) @RE16, Beijing, China, (2016) 2016-modeling-impact.pdf
Products go Green: Worst-Case Energy Consumption in Software Product Lines, Couto, Marco, Borba Paulo, Cunha Jácome, Fernandes João P., Pereira Rui, and Saraiva João , 21st International Systems and Software Product Line Conference, Sept 25-29, Sevilla, Spain, (2017) paper.pdf
Analyzing and Classifying Energy Consumption in Android Applications (in preparation), Couto, Marco, Cunha Jácome, Fernandes João P., Pereira Rui, and Saraiva João , (Submitted) paper.pdf
GreenDroid: A Tool for Analysing Power Consumption in the Android Ecosystem, Couto, Marco, Cunha Jácome, and Fernandes João Paulo , Proceedings of the 13th International Conference Informatics’2015, Propad, Slovakia, p.73-78, (2015) informatics2015.pdf
Static Energy Consumption Analysis in Variability Systems, Couto, Marco, Cunha Jácome, Fernandes João Paulo, Pereira Rui, and Saraiva João Alexandre , 2nd Green in Software Engineering Workshop (GInSEng’16), an event of the 4th International Conference on ICT for Sustainability (ICT4S), 29 Aug. - 1 Sep., Amsterdam, The Netherlands, (2016) Abstractginseng_2016_paper_1-2.pdf

Energy consumption is becoming an evident concern to software developers. This is even more notorious due to the propagation of mobile devices. Such propagation of devices is also influencing software development: a software system is now developed has a set of similar products sharing common features.
In this short paper, we describe our methodology aim at static and accurately predict the energy consumption of software products in such variability systems, typically called software product lines.

Extension and Implementation of ClassSheet Models, Cunha, Jácome, Fernandes João Paulo, Mendes Jorge, and Saraiva João , Proceedings of the 2012 IEEE Symposium on Visual Languages and Human-Centric Computing, Washington, DC, USA, p.19–22, (2012) Abstractvlhcc12.pdf

n this paper we explore the use of models in the context of spreadsheet engineering. We review a successful spreadsheet modeling language, whose semantics we further extend. With this extension we bring spreadsheet models closer to the business models of spreadsheets themselves. An addon for a widely used spreadsheet system, providing bidirectional model-driven spreadsheet development, was also improved to include the proposed model extension.

Towards an Evaluation of Bidirectional Model-driven Spreadsheets, Cunha, Jácome, Fernandes João Paulo, Mendes Jorge, and Saraiva João , User evaluation for Software Engineering Researchers, p.25–28, (2012) Abstractuser12.pdf

Spreadsheets are widely recognized as popular programming systems with a huge number of spreadsheets being created every day. Also, spreadsheets are often used in the decision processes of profit-oriented companies. While this illustrates their practical importance, studies have shown that up to 90% of real-world spreadsheets contain errors. In order to improve the productivity of spreadsheet end-users, the software engineering community has proposed to employ model-driven approaches to spreadsheet development. In this paper we describe the evaluation of a bidirectional model-driven spreadsheet environment. In this environment, models and data instances are kept in conformity, even after an update on any of these artifacts. We describe the issues of an empirical study we plan to conduct, based on our previous experience with end-user studies. Our goal is to assess if this model-driven spreadsheet development framework does in fact contribute to improve the productivity of spreadsheet users.

Model-Based Spreadsheet Engineering, Cunha, Jácome , March, (2011) Abstractthesis.pdf

Spreadsheets can be viewed as programming languages for non-professional programmers. These so-called ``end-user'' programmers vastly outnumber professional programmers creating millions of new spreadsheets every year. As a programming language, spreadsheets lack support for abstraction, testing, encapsulation, or structured programming. As a result, and as numerous studies have shown, the high rate of production is accompanied by an alarming high rate of errors. Some studies report that up to 90% of real-world spreadsheets contain errors. After their initial creation, many spreadsheets turn out to be used for storing and processing increasing amounts of data and supporting increasing numbers of users over long periods of time, making them complicated systems. An emerging solution to handle the complex and evolving software systems is Model-driven Engineering (MDE). To consider models as first class entities and any software artifact as a model or a model element is one of the basic principles of MDE. We adopted some techniques from MDE to solve spreadsheet problems. Most spreadsheets (if not all) lack a proper specification or a model. Using reverse engineering techniques we are able to derive various models from legacy spreadsheets. We use functional dependencies (a formalism that allow us to define how some column values depend on other column values) as building blocks for these models. Models can be used for several spreadsheet improvements, namely refactoring, safe evolution, migration or even generation of edit assistance. The techniques presented in this work are available under the framework HAEXCEL that we developed. It is composed of online and batch tools, reusable HASKELL libraries and extensions. A study with several end-users was organized to survey the impact of the techniques we designed. The results of this study indicate that the models can bring great benefits to spreadsheet engineering helping users to commit less errors and to work faster.

HaExcel: A Model-Based Spreadsheet Evolution System (Poster), Cunha, Jácome, Fernandes João Paulo, Mendes Jorge, and Saraiva João , 2011 IEEE Symposium on Visual Languages and Human-Centric Computing, September, (2011) Abstractposter.vlhcc11.png


Embedding and Evolution of Spreadsheet Models in Spreadsheet Systems, Cunha, Jácome, Fernandes João Paulo, Mendes Jorge, and Saraiva João , Proceedings of the 2011 IEEE Symposium on Visual Languages and Human-Centric Computing, Washington, DC, USA, p.186–201, (2011) Abstractvlhcc11.pdf

This paper describes the embedding of ClassSheet models in spreadsheet systems. ClassSheet models are well-known and describe the business logic of spreadsheet data. We embed this domain specific model representation on the (general purpose) spreadsheet system it models. By defining such an embedding, we provide end users a model-driven engineering spreadsheet developing environment. End users can interact with both the model and the spreadsheet data in the same environment. Moreover, we use advanced techniques to evolve spreadsheets and models and to have them synchronized. In this paper we present our work on extending a widely used spreadsheet system with such a model-driven spreadsheet engineering environment.

ES-SQL: Visually Querying Spreadsheets, Cunha, Jácome, Fernandes João Paulo, Mendes Jorge, Pereira Rui, and Saraiva João , Proceedings of the 2014 IEEE Symposium on Visual Languages and Human-Centric Computing, Washington, DC, USA, p.203–204, (2014) Abstractvlhcc14-td.pdf

This paper presents ES-SQL, an embedded tool for visually constructing queries over spreadsheets. This tool provides an expressive query environment which has knowledge on the business logic of spreadsheets, and by this knowledge it assists the user in defining the intended queries.

From Spreadsheets to Relational Databases and Back, Cunha, Jácome, Saraiva João, and Visser Joost , Proceedings of the 2009 ACM SIGPLAN Workshop on Partial Evaluation and Program Manipulation, New York, NY, USA, p.179–188, (2009) Abstractpepm09.pdf

This paper presents techniques and tools to transform spreadsheets into relational databases and back. A set of data refinement rules is introduced to map a tabular datatype into a relational database schema. Having expressed the transformation of the two data models as data refinements, we obtain for free the functions that migrate the data. We use well-known relational database techniques to optimize and query the data. Because data refinements define bidirectional transformations we can map such database back to an optimized spreadsheet. We have implemented the data refinement rules and we have constructed tools to manipulate, optimize and refactor Excel-like spreadsheets.

Towards a Catalog of Spreadsheet Smells, Cunha, Jácome, Fernandes João P., Ribeiro Hugo, and Saraiva João , Proceedings of the 12th International Conference on Computational Science and Its Applications - Volume Part IV, Berlin, Heidelberg, p.202–216, (2012) Abstracticcsa-sq12.pdf

Spreadsheets are considered to be the most widely used programming language in the world, and reports have shown that 90% of real-world spreadsheets contain errors. In this work, we try to identify spreadsheet smells, a concept adapted from software, which consists of a surface indication that usually corresponds to a deeper problem. Our smells have been integrated in a tool, and were computed for a large spreadsheet repository. Finally, the analysis of the results we obtained led to the refinement of our initial catalog.

Automatically Inferring ClassSheet Models from Spreadsheets, Cunha, Jácome, Erwig Martin, and Saraiva João , Proceedings of the 2010 IEEE Symposium on Visual Languages and Human-Centric Computing, Washington, DC, USA, p.93–100, (2010) Abstractvlhcc10.pdf

Many errors in spreadsheet formulas can be avoided if spreadsheets are built automatically from higher-level models that can encode and enforce consistency constraints. However, designing such models is time consuming and requires expertise beyond the knowledge to work with spreadsheets. Legacy spreadsheets pose a particular challenge to the approach of controlling spreadsheet evolution through higher-level models, because the need for a model might be overshadowed by two problems: (A) The benefit of creating a spreadsheet is lacking since the legacy spreadsheet already exists, and (B) existing data must be transferred into the new model-generated spreadsheet. To address these problems and to support the model-driven spreadsheet engineering approach, we have developed a tool that can automatically infer ClassSheet models from spreadsheets. To this end, we have adapted a method to infer entity/relationship models from relational database to the spreadsheets/ClassSheets realm. We have implemented our techniques in the HAEXCEL framework and integrated it with the ViTSL/Gencel spreadsheet generator, which allows the automatic generation of refactored spreadsheets from the inferred ClassSheet model. The resulting spreadsheet guides further changes and provably safeguards the spreadsheet against a large class of formula errors. The developed tool is a significant contribution to spreadsheet (reverse) engineering, because it fills an important gap and allows a promising design method (ClassSheets) to be applied to a huge collection of legacy spreadsheets with minimal effort.

Type-Safe Evolution of Spreadsheets, Cunha, Jácome, Visser Joost, Alves Tiago, and Saraiva João , Number DI-CCTC-10-09, (2010) Abstracttr_evolution.pdf

Spreadsheets are notoriously error-prone. To help avoid the introduction of errors when changing spreadsheets, models that capture the structure and inter-dependencies of spreadsheets at a conceptual level have been proposed. Thus, spreadsheet evolution can be made safe within the confines of a model. As in any other model/instance setting, evolution may not only require changes at the instance level but also at the model level. When model changes are required, the safety of instance evolution can not be guarded by the model alone. Coupled transformation of models and instances are supported by the 2LT platform and have been applied for transformation of algebraic datatypes, XML schemas, and relational database models. We have extended 2LT to spreadsheet evolution. We have designed an appropriate representation of spreadsheet models, including the fundamental notions of formulæ, references, and blocks of cells. For these models and their instances, we have designed coupled transformation rules that cover specific spreadsheet evolution steps, such as extraction of a block of cells into a separate sheet or insertion of columns in all occurrences of a repeated block of cells. Each model-level transformation rule is coupled with instance level migration rules from the source to the target model and vice versa. These coupled rules can be composed to create compound transformations at the model level that induce compound transformations at the instance level. With this approach, spreadsheet evolution can be made safe, even when model changes are involved.

A Quality Model for Spreadsheets, Cunha, Jácome, Fernandes João Paulo, Peixoto Christophe, and Saraiva João , Proceedings of the 8th International Conference on the Quality of Information and Communications Technology, Quality in ICT Evolution Track, p.231–236, (2012) Abstractquatic2012.pdf

In this paper we present a quality model for spreadsheets, based on the ISO/IEC 9126 standard that defines a generic quality model for software. To each of the software characteristics defined in the ISO/IEC 9126, we associate an equivalent spreadsheet characteristic. Then, we propose a set of spreadsheet specific metrics to assess the quality of a spreadsheet in each of the defined characteristics. In order to obtain the normal distribution of expected values for a spreadsheet in each of the metrics that we propose, we have executed them against all spreadsheets in the large and widely used EUSES spreadsheet corpus. Then, we quantify each characteristic of our quality model after computing the values of our metrics, and we define quality scores for the different ranges of values. Finally, to automate the atribution of a quality score to a given spreadsheet, according to our quality model, we have integrated the computation of the metrics it includes in both a batch and a web-based tool.

MDSheet: A Framework for Model-driven Spreadsheet Engineering, Cunha, Jácome, Fernandes João Paulo, Mendes Jorge, and Saraiva João , Proceedings of the 34rd International Conference on Software Engineering, p.1395–1398, (2012) Abstracticse12_tooldemo.pdf

n this paper, we present MDSHEET, a framework for the embedding, evolution and inference of spreadsheet models. This framework offers a model-driven software development mechanism for spreadsheet users.

Model-Based Programming Environments for Spreadsheets, Cunha, Jácome, Saraiva João, and Visser Joost , Programming Languages, Volume 7554, p.117–133, (2012) Abstractsblp12.pdf

Although spreadsheets can be seen as a flexible programming environment, they lack some of the concepts of regular programming languages, such as structured data types. This can lead the user to edit the spreadsheet in a wrong way and perhaps cause corrupt or redundant data. We devised a method for extraction of a relational model from a spreadsheet and the subsequent embedding of the model back into the spreadsheet to create a model-based spreadsheet programming environment. The extraction algorithm is specific for spreadsheets since it considers particularities such as layout and column arrangement. The extracted model is used to generate formulas and visual elements that are then embedded in the spreadsheet helping the user to edit data in a correct way. We present preliminary experimental results from applying our approach to a sample of spreadsheets from the EUSES Spreadsheet Corpus.

Refactoring meets Model-Driven Spreadsheet Evolution, Cunha, Jácome, Fernandes João Paulo, Martins Pedro, Pereira Rui, and Saraiva João , Proceedings of the 9th International Conference on the Quality of Information and Communications Technology, Quality in Model Driven Engineering Track, p.196–201, (2014) Abstractquatic14.pdf

Software refactoring is a well-known technique that provides transformations on software artifacts with the aim of improving their overall quality. In this paper we present a set of refactorings for ClassSheets, a modeling language that allows to specify the business logic of a spreadsheet in an object-oriented fashion. The set of refactorings that we propose allows us to improve the quality of these spreadsheet models. Moreover, it is implemented in a setting that guarantees that all model refactorings are automatically carried to all the corresponding (spreadsheet) instances, thus providing an automatic evolution of the data so it is always synchronized with the model.

SmellSheet Detective: A Tool for Detecting Bad Smells in Spreadsheets, Cunha, Jácome, Fernandes João Paulo, Mendes Jorge, Martins Pedro, and Saraiva João , Proceedings of the 2012 IEEE Symposium on Visual Languages and Human-Centric Computing, Washington, DC, USA, p.243–244, (2012) Abstractvlhcc12-td.pdf

This tool demo paper presents SmellSheet Detective: a tool for automatically detecting bad smells in spreadsheets. We have defined a catalog of bad smells in spreadsheet data which was fully implemented in a reusable library for the manipulation of spreadsheets. This library is the building block of the SmellSheet Detective tool, that has been used to detect smells in large, real-world spreadsheet within the EUSES corpus, in order to validate and evolve our bad smells catalog.

Querying Model-Driven Spreadsheets, Cunha, Jácome, Fernandes João Paulo, Mendes Jorge, Pereira Rui, and Saraiva João , Proceedings of the 2013 IEEE Symposium on Visual Languages and Human-Centric Computing, Washington, DC, USA, p.83–86, (2013) Abstractvlhcc2013-query.pdf

Spreadsheets are being used with many different purposes that range from toy applications to complete information systems. In any of these cases, they are often used as data repositories that can grow significantly. As the amount of data grows, it also becomes more difficult to extract concrete information out of them. This paper focuses on the problem of spreadsheet querying. In particular, we propose an expressive and composable technique where intuitive queries can be defined. Our approach builds on a model-driven spreadsheet development environment, and queries are expressed referencing entities in the model of a spreadsheet instead of in its actual data. Finally, the system that we have implemented relies on Google's query function for spreadsheets.