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Abstract With the spectacular development of pervasive computing and the widespread use of mobile technologies, the user usually resorts to a wide variety of user platforms. Moreover, the applications deployed on such platforms usually lack specific support for people suffering from disabilities. This is especially valid in the Tunisian context where the current status of digital accessibility is far from being perfect since the developer's community still ignores accessibility-related programming techniques. Consequently, further efforts are still required to resolve the issues related to the growing variety of available devices and of accessibility difficulties met by different categories of users. Therefore, in this paper we are introducing a model driven approach that aims to assist local and worldwide communities of developers throughout the development process of accessible user interfaces (UIs) targeting several emerging platforms. Based on a set of models from different abstraction levels followed by transformations, this approach provides a generic framework that integrates accessibility concerns starting from the design time. It allows the generation of accessible interfaces with a focus on the graphical and adaptation aspects on various platforms regardless of the developer expertise in UI accessibility. 1 Highlights • Improving the development of accessible applications for developers worldwide. • Metamodels of accessible user interface, interaction platforms, execution platforms. • Transformations from abstract accessible UI models to executable UIs. • Development of model editors to assist users create required models. • Evaluation of the framework to show the usability and efficiency of the approach. [ABSTRACT FROM AUTHOR]

Highlights • Automated verification of block diagram models. • Slope boundaries as new abstract domain. • Integrated symbolic and interval verification. • Block diagram case studies from research and industry. Abstract Model-based development is increasingly used in embedded systems, which are often deployed in a safety-critical environment. Verification techniques, supporting the development process can not only increase safety, but also help to speed up the process. In many cases models are designed with block diagrams, assisting rapid prototyping. However, automated verification is, thereafter, often applied to the resulting code. Instead of focusing on code, we apply verification techniques to models consisting of block diagrams and MATLAB code. We propose to combine a value and slope range analysis, with symbolic methods. In this way, our concept can not only prove properties in models, but also check rate requirements automatically, which arise from physical constraints of the environment. We evaluate our work in case studies from ongoing research projects. These case studies cover the domains of clinical intensive care, autonomous drone control and driver assistance. All systems are also evaluated with a commercial verification tool, highlighting benefits of the tool and our implementation. [ABSTRACT FROM AUTHOR]

The performance of electric bicycles for the mountainous region depends on a simulation model and experimental study covers dynamic characteristics, power requirement to propel the electric cycle, and different operating conditions such as slope gradient, a mass of the user, wind speed, wheel diameter, and length of the crankshaft. The study highlights the mathematical model of the electric bicycle with dynamic characteristics and calculates the power required to propel the cycle in the mountainous region under a parallel hybrid mode. The application is supported with an android operating system, which keeps track of the cycle issued to potential users. The system has a mechanism in place, which issues the cycle to only those users who unblock it through the application by scanning the correct quick response code. The Simulink is used for mathematical model development and analyzing dynamic characteristics of the electric bicycle. The dSPACE development board framework is used for the experimental validation as a solver to capture multiple input-output parameters. The results show that an electric bicycle motor generates 23.87 Nm of torque at 8 km/h and requires 240 W of power to propel the electric cycle at 34 km/h. The electric bicycle consumes an average current of 8.2 A at a zero slope gradient. It also shows that required power changes to 260 W at 2. 9 o slope gradient, 310 W at 4. 8 o slope gradient and 350 W at 7. 1 o slope gradient. [ABSTRACT FROM AUTHOR]

Advances in scheduling theory have given designers of control systems greater flexibility over their choice of timing requirements. This could lead to systems becoming more responsive and more maintainable. However, experience has shown that engineers find it difficult to exploit these advantages due to the difficulty in determining the ‘real’ timing requirements of systems and therefore the techniques have delivered less benefit than expected. Part of the reason for this is that the models used by engineers when developing systems do not allow for emergent properties such as timing. The paper presents an approach and framework for addressing the problem of identifying an appropriate and valid set of timing requirements in order that the best use can be made of the advances in scheduling theory by the use of modelling techniques that allow for emergent properties such as timing behaviour. [Copyright &y& Elsevier]