12 research outputs found
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Patterns for the design of secure and dependable software defined networks
In an interconnected world, cyber and physical networks face a number of challenges that need to be resolved. These challenges are mainly due to the nature and complexity of interconnected systems and networks and their ability to support heterogeneous physical and cyber components simultaneously. The construction of complex networks preserving Security and Dependability (S&D) properties is necessary to avoid system vulnerabilities, which may occur in all the different layers of Software Defined Networking (SDN) architectures. In this paper, we present a model based approach to support the design of secure and dependable SDN. This approach is based on executable patterns for designing networks able to guarantee S&D properties and can be used in SDN networks. The design patterns express conditions that can guarantee specific S&D properties and can be used to design networks that have these properties and manage them during their deployment. To evaluate our pattern approach, we have implemented executable pattern instances, in a rule-based reasoning system, and used them to design and verify wireless SDN networks with respect to availability and confidentiality. To complete this work, we propose and evaluate an implementation framework in which S&D patterns can be applied for the design and verification of SDN networks
INTERNATIONAL BACCALAUREATE PRIMARY YEARS TEACHERS´ PERCEPTIONS ON EDUCATING STUDENTS WITH DYSLEXIA
Global organizations, such as the United Nations, have increasingly focused on ensuring that students with special needs are receiving high quality education. With schools in over 158 countries worldwide, the International Baccalaureate (IB) system provides an ideal forum to investigate if students with dyslexia globally are receiving adequate instruction. Yet, there is a general lack of research investigating IB schools, specifically for students with learning differences such as dyslexia. Providing a curriculum framework for students ages three to 12, the Primary Years Program (PYP) forms the foundation of the IB system. This quantitative research study used online survey methods to assess IB PYP teacher perceptions of educating students with dyslexia with a global sample of IB PYP teachers. Through a combination of descriptive and regression analyses, this research describes overall IB PYP teacher understanding of dyslexia, as well as identifies potential educational barriers that affect students with dyslexia. As a result of this research, IB instructors and administrators may have a better understanding of potential areas for growth in order to ensure that students internationally with dyslexia receive high quality education
Supporting Pattern-Based Dependability Engineering via Model-Driven Development: Approach, tool-support and empirical validation
International audienceSafety-critical systems require a high level of safety and integrity. Therefore, generating such systems involves specific software building processes. Many domains are not traditionally involved in these types of software problems and must adapt their current processes accordingly. Typically, such requirements are developed ad hoc for each system, preventing further reuse beyond the domain-specific boundaries. This paper proposes a solution for software system development based on the reuse of dedicated subsystems, i.e., so-called dependability patterns that have been pre-engineered to adapt to a specific domain. We use Model-Driven Engineering (MDE) to describe dependability patterns and a methodology for developing dependable software systems using these patterns. Moreover, we describe an operational architecture for development tools to support the approach. An empirical evaluation of the proposed approach is presented through its practical application to a case study in the railway domain, which has strong dependability requirements, to support a pattern-based development approach. This case study is followed by a survey to better understand the perceptions of practitioners regarding our approach