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Specification of modelling languages in a flexible meta-model architecture

Originally, meta-models were used to specify the structure (abstract syntax) of modelling languages. This is reflected both in meta-languages like MOF and Ecore, and the four-layer meta-model architecture. Presently, meta-modelling is used for specification of complete languages. In this situation, it turns out that the traditional meta-languages are not always expressive enough to capture all language aspects. This usually implies the use of more than one metalanguage in the meta-model architecture to cover the different language aspects. There are many approaches to address this challenge. In this paper, we analyze these approaches, and based on this analysis, we re-think the meta-model architecture focusing on complete language specifications. In our meta-model architecture, each aspect of a language conforms to an aspect-specific meta-language at the level above, and models can reside at different levels depending on their context and use. This meta-model architecture is easier to understand, more flexible and more extensible; therefore it may be useful in the design of meta-model-based language specification platforms, as well as for promoting the understanding of the principles of meta-modelling.

Sudoku --- A Language Description Case Study

A complete language description includes the structure as well as constraints, textual representation, graphical representation, and behaviour (transformation and execution). As a case study in language description, we consider Sudoku as a language, where a Sudoku puzzle is an instance of the language. Thus we are able to apply meta-model-based technologies for the creation of a language description for Sudoku, including correctness checking of a puzzle, and solving strategies. We identify what has to be expressed and how this can be done with the technology available today.

MOF-VM: Instantiation revisited

The Model-Driven Architecture (MDA) is based on an understanding of a hierarchy of levels that are placed on top of each other and that are connected with instantiation. For practical MDA use, it is important to be clear about the kinds of objects that reside on the different levels and the relations between them as well as relations to objects outside of the MDA domain. This article aims at enhancing the understanding of these objects and relations by relating them to a virtual MOF machine.

A scratch-based graphical policy editor for XACML

This paper proposes a policy-maker-friendly editor for the extensible Access Control Markup Language (XACML) based on the programming language Scratch. Scratch is a blocks-based programming language designed for teaching children programming, which allows users to build programs like a puzzle. We take this concept one step further with an XACML policy editor based on the graphic programming elements of Scratch implemented in Smalltalk. This allows for aiding the user on how to build policies by grouping blocks and operators that fit together and also indicating which blocks that will stick together. It simplifies building the XACML policies while still having an XACML “feel” of the graphic policies.

Formal verification of a Cooperative Automatic Repeat reQuest MAC protocol

Cooperative communications, in which a relay node helps the source node to deliver its packets to the destination node, are able to obtain significant benefits in terms of transmission reliability, coverage extension and energy efficiency. A Cooperative Automatic Repeat reQuest (C-ARQ) MAC protocol has been recently proposed to exploit cooperative diversity at the MAC layer. In this paper, we validate the integrity and the validity of the C-ARQ protocol using formal methods. The protocol logic is modeled in SDL and implemented in PROMELA. The functionality of the C-ARQ protocol is verified through simulations and verifications using SPIN.

Teaching Model Driven Language Handling

Many universities teach computer language handling by mainly focussing on compiler theory, although MDD (model-driven development) and meta-modelling are increasingly important in the software industry as well as in computer science. In this article, we share some experiences from teaching a course in computer language handling where the focus is on MDD principles. We discuss the choice of tools and technologies used in demonstrations and exercises, and also give a brief glimpse of a prototype for a simple meta-model-based language handling tool that is currently being designed and considered for future use in teaching.

Modelling accessibility constraints

This paper describes the combination of research topics from two projects focusing on web accessibility testing, and on metamodelling and high-level specification languages. This combination leads to a novel approach to accessibility assessment that will improve the understanding of accessibility issues, and explore the potential for generating executable accessibility tests based on accessibility constraint models

Streamlining Assessment using a Knowledge Metric.

This paper proposes an efficient tool-supported methodology for marking student assignment answers according to a knowledge metric. This metric gives a coarse hint of student answer quality based on Shannon entropy. The methodology supports marking student assignments across each sub-assignment answer, and the metric sorts the answers, so that the most comprehensive textual answers typically get the highest ranking, and can be marked first. This ensures that the teacher quickly gets an overview over the range of answers, which allows for determining a consistent marking scale in order to reduce the risk of scale sliding or hitting the wrong scale level during marking. This approach is significantly faster and more consistent than using the traditional approach, marking each assignment individually.

Teaching computer language handling - from compiler theory to meta-modelling

Most universities teach computer language handling by mainly focussing on compiler theory, although MDA (model-driven architecture) and meta-modelling are increasingly important in the software industry as well as in computer science. In this article, we investigate how traditional compiler theory compares to meta-modelling with regard to formally defining the different aspects of a language, and how we can expand the focus in computer language handling courses to also include meta-model-based approaches. We give an outline of a computer language handling course that covers both paradigms, and share some experiences from running a course based on this outline at the University of Agder.

Universal Design of ICT for Emergency Management

The primary objectives of this article are to give a systematic overview of the current state of the emerging research field of Universal Design of Information and Communication Technology (ICT) for Emergency Management, and to highlight high-impact research opportunities to ensure that the increasing introduction of ICT in Emergency Management can contribute to removing barriers instead of adding more barriers, in particular for the elderly and people with disabilities. A systematic review on various literature with respect to Universal Design, ICT and Emergency Management between 2008 to 2018 was employed in this study, and reviewed systematically using a predefined framework. The ultimate goal of this effort is to answer the following questions: (1) How strong is the coverage of research on Universal Design of ICT in Emergency Management in the different categories of Emergency Management ICT tools? (2) What potential next steps in research on Universal Design of ICT in Emergency Management have the highest potential impact in terms of improved Emergency Management and reduced Disaster Risk? We identify a set of gaps in the literature, indicating that there are some challenges where Universal Design is not so much taken into account in the technology development to support the different phases of the crisis management cycle. We also derive a research agenda based on areas that are missing in the literature, to serve a future research in the area of universal design and Emergency Management.