Conference Papers

Cledou G, Barbosa L.  Submitted.  Modeling Families of Public Licensing Services: A Case Study. FME Workshop on Formal Methods in Software Engineering (FormaliSE). formalise2017.pdf
Cledou G, Nakajima S.  2019.  A Net-Based Formal Framework for Causal Loop Diagrams. Complex Systems Design {&} Management Asia. :1–12. Abstractcsdm2018.pdf

Causal Loop Diagrams (CLDs) are a modeling tool employed in Business Dynamics. Such a diagram consists of many tightly coupled loops to capture dynamic behavior of systems. Intuitive operational semantics, describing how changes are propagated among the loops, provide a basis for model animation or manual inspection. They are, however, not precise enough to enable automated property checking. This paper proposes and defines a net-based formal framework, showing true concurrency, so that automated analysis is made possible.

Cledou G, Proença J, Sputh BHC, Verhulst E.  2019.  Coordination of Tasks on a Real-Time OS. Coordination Models and Languages. :250–266. Abstract

VirtuosoNext{\$}{\$}^{\{}{\backslash}text {\{}TM{\}}{\}}{\$}{\$}is a distributed real-time operating system (RTOS) featuring a generic programming model dubbed Interacting Entities. This paper focuses on these interactions, implemented as so-called Hubs. Hubs act as synchronisation and communication mechanisms between the application tasks and implement the services provided by the kernel as a kind of Guarded Protected Action with a well defined semantics. While the kernel provides the most basic services, each carefully designed, tested and optimised, tasks are limited to this handful of basic hubs, leaving the development of more complex synchronization and communication mechanisms up to application specific implementations. In this work we investigate how to support a programming paradigm to compositionally build new services, using notions borrowed from the Reo coordination language, and relieving tasks from coordination aspects while delegating them to the hubs. We formalise the semantics of hubs using an automata model, identify the behaviour of existing hubs, and propose an approach to build new hubs by composing simpler ones. We also provide tools and methods to analyse and simplify hubs under our automata interpretation. In a first experiment several hub interactions are combined into a single more complex hub, which raises the level of abstraction and contributes to a higher productivity for the programmer. Finally, we investigate the impact on the performance by comparing different implementations on an embedded board.

Cledou G, Proença J, Barbosa L.  2017.  Composing Families of Timed Automata. 7th IPM International Conference on Fundamentals of Software Engineering. Abstractifta.pdf


Cledou G, Proença J, Barbosa LS.  2017.  A Refinement Relation for Families of Timed Automata. XX Brazilian Symposium on Formal Methods. Abstractiftarefinement.pdf

Software Product Lines (SPLs) are families of systems that share a high number of common assets while differing in others. In component-based systems, components themselves can be SPLs, i.e., each component can be seen as a family of variations, with different interfaces and functionalities, typically parameterized by a set of features and a feature model that specifies the valid combinations of features. This paper explores how to safely replace such families of components with more refined ones. We propose a notion of refinement for Interface Featured Timed Automata (IFTA), a formalism to model families of timed automata with support for multi-action transitions. We separate the notion of IFTA refinement into behavioral and variability refinement, i.e., the refinement of the underlying timed automata and feature model. Furthermore, we define behavioral refinement for the semantic level, i.e., transition systems, as an alternating simulation between systems, and lift this definition to IFTA refinement. We illustrate this notion with examples throughout the text and show that refinement is a pre-order and compositional.

Cledou MG, Barbosa LS.  2016.  An Ontology for Licensing Public Transport Services. Proceedings of the 9th International Conference on Theory and Practice of Electronic Governance. :230–239. Abstractan_ontology_for_licensing_public_transport_services.pdf

By 2050 it is expected that 66% of the world population will reside in cities, compared to 54% in 2014. One particular challenge associated to urban population growth refers to transportation systems, and as an approach to face it, governments are investing significant efforts enhancing public transport services. An important aspect of public transport is ensuring that licensing of such services fulfill existing government regulations. Due to the differences in government regulations, and to the difficulties in ensuring the fulfillment of their specific features, many local governments develop tailored Information and Communication Technology (ICT) solutions to automate the licensing of public transport services. In this paper we propose an ontology for licensing such services following the REFSENO methodology. In particular, the ontology captures common concepts involved in the application and processing stage of licensing public bus passenger services. The main contribution of the proposed ontology is to define a common vocabulary to share knowledge between domain experts and software engineers, and to support the definition of a software product line for families of public transport licensing services.

Casal J, Cledou MG.  2014.  Understanding Students' Mobility Habits Towards the Implementation of an Adaptive Ubiquitous Platform. Proceedings of the International Conference on Information Systems and Design of Communication - ISDOC '14. :67–72. Abstractisdoc14.pdf

Adapting technological environments to users is a concern since Mark Weiser launched the concept of ubiquitous computing and, in order to do that, is necessary to understand users' characteristics. In this context, the purpose of this paper is to present a study about students' mobility habits within a university campus, having the intention of getting insights towards the best place to set an interactive public display and of predicting the main characteristics of the audience that will be present on that spot in forthcoming periods. Thus, the envisioned results of this work will allow the adaptation of the contents exhibited on the device to the audience. To perform the study, a set of logs of accesses to the university's Wi-Fi was used, data mining techniques were implemented and forecasting models were built, using the line of work suggested by the CRISP-DM methodology. As result, students profile were built based on past wireless accesses and on their scholar schedules, and three time series models were used (Holt-Winters, Seasonal Naive and Simple Exponential Smoothing) to predict the presence of students on the envisioned spot in future periods.

Cledou MG.  2014.  A Virtual Factory for Smart City Service Integration. Proceedings of the 8th International Conference on Theory and Practice of Electronic Governance. :536–539. Abstracticegov2014paper.pdf

In the last years, new technologies - referred as emerging information and communication technologies (EICTs), have appeared and are immersed in peoples’ lives assisting them and facilitating their daily activities. Taking advantage of the diffusion and infusion of these technologies, governments are using EICTs to deliver better public services to citizens. However, to address citizens’ demands and to provide customer oriented services governments face various types of challenges. The aim of this research work is to provide solutions to some of the challenges, in particular to the rapid development of electronic public services (EPS) and the service integration in the context of development of smart cities. Following the aim, we propose an approach, called Virtual Factory for Smart City Service Integration. The idea of the virtual factory is to provide a framework to automatically produce software based on a given set of specifications of a family of EPS taking advantage of similarities in the EPS business processes. The expected contributions of this research work is to produce a domain specific language (DSL) for service specification and supporting tools that based on the produced specifications, workflow techniques and ideas of software product lines (SPL) can automatically produce software applications for EPS that can be easily parameterized and completed.

Cledou MG, Fernandes S, Estevez E.  2013.  WeLEaD: Collaborative Toolkit for Learning, Engaging and Deciding. Proceedings of the 7th International Conference on Theory and Practice of Electronic Governance. :378–379. Abstracticegov13.pdf

Open Government is a new trend in public governance, based on the principles of transparency, collaboration and participation, currently being adopted by many countries around the world including 63 members of the Open Government Partnership. Operationalizing such principles requires developing certain capabilities among citizens and relevant government actors. For example, participation requires citizens to be informed and engaged, and achieving this requires government to build capabilities in using appropriate tools for informing and engaging. This poster paper outlines a research work in progress for developing an e-Participation toolkit called WeLEaD - Collaborative Toolkit for Learning, Engaging and Deciding. The toolkit will comprise an integrated set of advanced e-participation tools, based on the peer-production approach to collaborative teaching and learning: 1) to help citizens learn from each other about relevant issues on the public policy agenda; 2) to engage policy-makers, government executives, citizens and other non- state actors in informed discussions on how to advance this agenda; and 3) to reflect the outcomes of such discussions, including citizen views and opinions, in government's policy- making processes. The toolkit will also include technical and organizational guidelines for conducting e-Participation initiatives, including the use of such tools.