Combining SysML and AADL for the design, validation and implementation of critical systems

The realization of critical systems goes through multiple phases of specification, design, integration, validation, and testing. It starts from high-level sketches down to the final product. Model-Based Design has been acknowledged as a good conveyor to capture these steps. Yet, there is no universal solution to represent all activities. Two candidates are the OMG-based SysML to perform high-level modeling tasks, and the SAE AADL to perform lower-level ones, down to the implementation. The paper shares an experience on the seamless use of SysML and the AADL to model, validate/verify and implement a flight management system

Agogo Presbyterian College of Education Under the Missionaries and After Take-Over by the Government (1931-2013): A Comparative Study

The study analyzed the Agogo Presbyterian College of Education (1930-1971) and when it was taken over by the Government (1972-2013). This became relevant in the wake of the recent plea by the churches that the Government should hand over Mission Schools to the churches. The study therefore examines the state of management and leadership and infrastructural development both under the regime of the Missionaries and the Government. It also sought to assess academic standard of the students, and the discipline of the College, qualification of the teachers, supervision, and students’ patronage of library and entry grade of students to the College with the view of establishing the progression or retrogression over the period. In doing this, a comparative study was undertaken and data were derived from archival materials of the Agogo Presbyterian College of Education, and direct interviews with past Principals and Administrators of the College. The results revealed that despite an increase in student-intake (210 students in 1942 to 750 students in 2014) with a corresponding increase of teachers (from 5 missionary teachers with lower academic degrees in 1931 to 28 teachers with masters qualifications), inadequate infrastructural development; lack of discipline and competitions among students have characterized APCE since it was managed by the Government as compared to the Missionaries. The study recommends that the Government would complete the construction of the students‟ hall complex, and also put up large auditorium and classroom blocks to accommodate the high students’ intake in the College to enhance education delivery

Leveraging Ada 2012 and SPARK 2014 for assessing generated code from AADL models

Modeling of Distributed Real-time Embedded systems using Architecture Description Language provides the foundations for various levels of analysis: scheduling, reliability, consis- tency, etc.; but also allows for automatic code generation. A challenge is to demonstrate that generated code matches quality required for safety-critical systems. In the scope of the AADL, the Ocarina toolchain proposes code generation towards the Ada Ravenscar profile with restrictions for High- Integrity. It has been extensively used in the space domain as part of the TASTE project within the European Space Agency. In this paper, we illustrate how the combined use of Ada 2012 and SPARK 2014 significantly increases code quality and exhibits absence of run-time errors at both run-time and generated code levels

Ada, the programming language of choice for the UPMSAT-2 satellite

The proper selection of development mechanisms and tools is essential for the final success of any engineering project. This is also true when it comes to software development. Furthermore, when the system shows very specific and hard to meet requirements, as it happens for high-integrity real-time systems, the appropriate selection is crucial. For this kind of systems, Ada has proven to be a successful companion, and satellites are not an exception. The paper presents the reasons behind the selection of Ada for the UPMSat-2 development, along with the experience and examples on its usage

Faculty Visions for Teaching Web Accessibility within LIS Curricula in the United States: A Qualitative Study

This qualitative study explores the understanding and perspectives of faculty in US library and information science (LIS) programs about teaching web accessibility. “Web accessibility” can be defined simply as making websites accessible for all, including people with disabilities. Eight LIS professors and two graduate LIS students or recent alumni with interests in accessibility were interviewed for the study. Results showed that, although some faculty were novices, most interviewees thought it would be beneficial to teach web accessibility in a variety of LIS courses. However, despite the seeming consensus, discussion of incorporating web accessibility into curricula was rare. This study explores possible reasons for the marginalization of web accessibility in LIS. The authors contend that greater support for initiatives to integrate web accessibility into LIS curricula is essential for enabling LIS practitioners to comply with legal standards and with LIS values of inclusion

Certification of open-source software : a role for formal methods?

Despiteitshugesuccessandincreasingincorporationincom- plex, industrial-strength applications, open source software, by the very nature of its open, unconventional, distributed development model, is hard to assess and certify in an effective, sound and independent way. This makes its use and integration within safety or security-critical systems, a risk. And, simultaneously an opportunity and a challenge for rigourous, mathematically based, methods which aim at pushing software analysis and development to the level of a mature engineering discipline. This paper discusses such a challenge and proposes a number of ways in which open source development may benefit from the whole patrimony of formal methods.L. S. Barbosa research was partially supported by the CROSS project, under contract PTDC/EIA-CCO/108995/2008

On Using Machine Learning to Identify Knowledge in API Reference Documentation

Using API reference documentation like JavaDoc is an integral part of software development. Previous research introduced a grounded taxonomy that organizes API documentation knowledge in 12 types, including knowledge about the Functionality, Structure, and Quality of an API. We study how well modern text classification approaches can automatically identify documentation containing specific knowledge types. We compared conventional machine learning (k-NN and SVM) and deep learning approaches trained on manually annotated Java and .NET API documentation (n = 5,574). When classifying the knowledge types individually (i.e., multiple binary classifiers) the best AUPRC was up to 87%. The deep learning and SVM classifiers seem complementary. For four knowledge types (Concept, Control, Pattern, and Non-Information), SVM clearly outperforms deep learning which, on the other hand, is more accurate for identifying the remaining types. When considering multiple knowledge types at once (i.e., multi-label classification) deep learning outperforms na\"ive baselines and traditional machine learning achieving a MacroAUC up to 79%. We also compared classifiers using embeddings pre-trained on generic text corpora and StackOverflow but did not observe significant improvements. Finally, to assess the generalizability of the classifiers, we re-tested them on a different, unseen Python documentation dataset. Classifiers for Functionality, Concept, Purpose, Pattern, and Directive seem to generalize from Java and .NET to Python documentation. The accuracy related to the remaining types seems API-specific. We discuss our results and how they inform the development of tools for supporting developers sharing and accessing API knowledge. Published article: https://doi.org/10.1145/3338906.333894