Model Based Development of Quality-Aware Software Services

Modelling languages and development frameworks give support for functional and structural description of software architectures. But quality-aware applications require languages which allow expressing QoS as a first-class concept during architecture design and service composition, and to extend existing tools and infrastructures adding support for modelling, evaluating, managing and monitoring QoS aspects. In addition to its functional behaviour and internal structure, the developer of each service must consider the fulfilment of its quality requirements. If the service is flexible, the output quality depends both on input quality and available resources (e.g., amounts of CPU execution time and memory). From the software engineering point of view, modelling of quality-aware requirements and architectures require modelling support for the description of quality concepts, support for the analysis of quality properties (e.g. model checking and consistencies of quality constraints, assembly of quality), tool support for the transition from quality requirements to quality-aware architectures, and from quality-aware architecture to service run-time infrastructures. Quality management in run-time service infrastructures must give support for handling quality concepts dynamically. QoS-aware modeling frameworks and QoS-aware runtime management infrastructures require a common evolution to get their integration

Combined automotive safety and security pattern engineering approach

Automotive systems will exhibit increased levels of automation as well as ever tighter integration with other vehicles, traffic infrastructure, and cloud services. From safety perspective, this can be perceived as boon or bane - it greatly increases complexity and uncertainty, but at the same time opens up new opportunities for realizing innovative safety functions. Moreover, cybersecurity becomes important as additional concern because attacks are now much more likely and severe. However, there is a lack of experience with security concerns in context of safety engineering in general and in automotive safety departments in particular. To address this problem, we propose a systematic pattern-based approach that interlinks safety and security patterns and provides guidance with respect to selection and combination of both types of patterns in context of system engineering. A combined safety and security pattern engineering workflow is proposed to provide systematic guidance to support non-expert engineers based on best practices. The application of the approach is shown and demonstrated by an automotive case study and different use case scenarios.EC/H2020/692474/EU/Architecture-driven, Multi-concern and Seamless Assurance and Certification of Cyber-Physical Systems/AMASSEC/H2020/737422/EU/Secure COnnected Trustable Things/SCOTTEC/H2020/732242/EU/Dependability Engineering Innovation for CPS - DEIS/DEISBMBF, 01IS16043, Collaborative Embedded Systems (CrESt

Towards a new vision of Information System Engineering.

Information Technologies bear the potential of new uses. These uses provoke a new organization which induces a new vision of software engineering. Under the influence of globalization, and the impact of Information and Communication Technologies (ICT) that modify radically our relationship with space and time, the hierarchical company locked up on its local borders becomes an Extended Company, without borders, opened and adaptable. In this context, this paper proposes a shift in the way the design of information systems is viewed, so that the digital information system and potential user are in harmony right from the design stage of the system. The goal is to help to design systems that are useful. It will therefore be a matter of distributed intelligence of the situation in terms of interactions and cooperative partners rather than in terms of a more passive user. This means putting at the disposal of the user, seen as a "partner", a system that will help him or her think more efficiently about a situation. The approach adopted is a global philosophy based on business process management within the framework of all the methodological principles. The research described here is therefore a contribution to the software engineering.User; Software Engineering; Information System; Business Process Management; Extended Company; Digital Information System;

ACon: A learning-based approach to deal with uncertainty in contextual requirements at runtime

Context: Runtime uncertainty such as unpredictable operational environment and failure of sensors that gather environmental data is a well-known challenge for adaptive systems. Objective: To execute requirements that depend on context correctly, the system needs up-to-date knowledge about the context relevant to such requirements. Techniques to cope with uncertainty in contextual requirements are currently underrepresented. In this paper we present ACon (Adaptation of Contextual requirements), a data-mining approach to deal with runtime uncertainty affecting contextual requirements. Method: ACon uses feedback loops to maintain up-to-date knowledge about contextual requirements based on current context information in which contextual requirements are valid at runtime. Upon detecting that contextual requirements are affected by runtime uncertainty, ACon analyses and mines contextual data, to (re-)operationalize context and therefore update the information about contextual requirements. Results: We evaluate ACon in an empirical study of an activity scheduling system used by a crew of 4 rowers in a wild and unpredictable environment using a complex monitoring infrastructure. Our study focused on evaluating the data mining part of ACon and analysed the sensor data collected onboard from 46 sensors and 90,748 measurements per sensor. Conclusion: ACon is an important step in dealing with uncertainty affecting contextual requirements at runtime while considering end-user interaction. ACon supports systems in analysing the environment to adapt contextual requirements and complements existing requirements monitoring approaches by keeping the requirements monitoring specification up-to-date. Consequently, it avoids manual analysis that is usually costly in today’s complex system environments.Peer ReviewedPostprint (author's final draft

A comprehensive fractal approach in determination of the effective thermal conductivity of gas diffusion layers in polymer electrolyte membrane fuel cells

The challenges in the fuel cell industry is to produce the efficient thermal and water management for accurate determination of the effectiveness thermal conductivity of gas diffusion layers (GDL) used in polymer electrolyte membrane fuel cells (PEMFC‟s). This is one of the factors affecting the durability of a fuel cell and need to get a solution to minimize costs and optimize the use of electrodes and cells. The main objectives of this research focus on the capability of the fractal approach for estimation the effectiveness of thermal conductivity of gas diffusion layer. Moreover, on this research also to propose modified fractal equations in determination of the effective thermal conductivity of GDL in PEMFCs based on previous study. Other objectives in this study are demonstrated the thermal conductivity of GDL treated with PTFE contents by using through-plane thermal conductivity experiment method. The through-plane measurement (experiment method) has been used in estimating through-plane thermal conductivity of the GDL. Thermal resistance for GDL also has been investigated under compression pressure 0.1 MPa until 1.0 MPa. In fractal equation, the determination of tortuous and pore fractal dimension can be done by using Scanning Electron Microscopy (SEM) method. Determination of effectiveness thermal conductivity using of fractal equation with slightly modified. In findings, it was found that fractal equation have been modified and measured on the GDL parameter characteristics. It was shown that the value of the effectiveness thermal conductivity of the sample using fractal approach is in good agreement with the experimental value. Finally, all the effective thermal conductivity measured by experimental and fractal approach have been determined with the variant temperature and compression pressure to show the validation result between of this two methods