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  • 51.
    Alemzadeh, H.
    et al.
    University of Virginia, United States.
    Barbosa, R.
    University of Coimbra, Portugal.
    Brancati, F.
    Resil Tech S.r.l, Italy.
    Gallina, Barbara
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lawford, M.
    McMaster University, Canada.
    Natella, R.
    Federico II University of Naples, Italy.
    Netkachova, K.
    City University of London, United Kingdom.
    Pietrantuono, R.
    Federico II University of Naples, Italy.
    Silva, N.
    CRITICAL Software S.A, Portugal.
    Message from the WoSoCer workshop organizers2017Ingår i: Proceedings - 2017 IEEE 28th International Symposium on Software Reliability Engineering Workshops, ISSREW 2017, s. xxxviii-, artikel-id 8109232Artikel i tidskrift (Refereegranskat)
  • 52.
    Alexander, Karlsson
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Design and Development of a Wireless Multipoint E-stop System for Autonomous Haulers2018Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Safety-related functions are important in autonomous industrial applications and are featured in an extensive body of work contained within the standards. The implementation of safety-related systems is commonly done by an external company at a great cost and with limited flexibility. Thus, the objective of this thesis was to develop and implement a safety-related system using o-the-shelf products and to analyse how well it can comply with the established standards of safety-related functions. This work has sought to review the current standards for safety-functions, the eectsof harsh radio environments on safety-related systems, and how to validate the safety-function.The system development process was used to gain knowledge by rst building the concept based on pre-study. After the pre-study was nished, the process moved to the development of software, designed to maintain a wireless heartbeat as well as to prevent collisions between the autonomous and manual-driven vehicles at a quarry, and implementation of the system in real hardware. Finally, a set of software (simulations) and hardware (measurements in an open-pit mine) tests were performed to test the functionality of the system. The wireless tests showed that the system adhered to the functional requirements set by the company, however, the evaluated performance level according to ISO 13849-1 resulted in performance level B which is insucient for a safety-related function. This work demonstrates that it is not possible to develop a safety-related system using the off-the-shelf products chosen, without hardware redundancy.

  • 53.
    Alirezaie, Marjan
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Renoux, Jennifer
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Köckemann, Uwe
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kristoffersson, Annica
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Karlsson, Lars
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Blomqvist, Eva
    RISE SICS East, Linköping, Sweden.
    Tsiftes, Nicolas
    RISE SICS, Stockholm, Sweden.
    Voigt, Thiemo
    RISE SICS, Stockholm, Sweden.
    Loutfi, Amy
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    An Ontology-based Context-aware System for Smart Homes: E-care@home2017Ingår i: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 17, nr 7, artikel-id 1586Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Smart home environments have a significant potential to provide for long-term monitoring of users with special needs in order to promote the possibility to age at home. Such environments are typically equipped with a number of heterogeneous sensors that monitor both health and environmental parameters. This paper presents a framework called E-care@home, consisting of an IoT infrastructure, which provides information with an unambiguous, shared meaning across IoT devices, end-users, relatives, health and care professionals and organizations. We focus on integrating measurements gathered from heterogeneous sources by using ontologies in order to enable semantic interpretation of events and context awareness. Activities are deduced using an incremental answer set solver for stream reasoning. The paper demonstrates the proposed framework using an instantiation of a smart environment that is able to perform context recognition based on the activities and the events occurring in the home.

  • 54.
    Almér, Alexander
    et al.
    Chalmers University of Technology and Gothenburg University, Sweden.
    von Hautwitz, Rickard
    Chalmers University of Technology and Gothenburg University, Sweden.
    Dodig-Crnkovic, Gordana
    Chalmers University of Technology and Gothenburg University, Sweden.
    Collective Cognition and Distributed Information Processing from Bacteria to Humans: Proc. AISB Conference Kent 2015.2015Ingår i: 41st Annual Convention of the Society for the Study of Artificial Intelligence and the Simulation of Behaviour: (AISB 2015), 2015, s. 119-124Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of this paper is to propose a general infocomputational model of cognition that can be applied to living organisms from the level of a single cell´s cognition to the level of groups of increasingly complex organisms with social, distributed cognition. We defend the project of new cognitivism, which unlike the old one acknowledges the central role of embodiment for cognition. Information processing going on in a cognising agent range from transduction of chemical signals and “quorum sensing” in bacteria, via simple local rules of behaviour that insects follow and that manifest themselves as “swarm intelligence”, to human level cognition with full richness of human languages and other systems of communication.

  • 55.
    Altarabichi, Mohammed Ghaith
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Ahmed, Mobyen Uddin
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Begum, Shahina
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Supervised Learning for Road Junctions Identification using IMU2019Ingår i: First International Conference on Advances in Signal Processing and Artificial Intelligence ASPAI' 2019, 2019Konferensbidrag (Refereegranskat)
  • 56.
    Altarabichi, Mohammed Ghaith
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Ahmed, Mobyen Uddin
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Begum, Shahina
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Ciceri, Maria Rita
    Università Cattolica del Sacro Cuore di Milano, Italy.
    Balzarotti, Stefania
    Università Cattolica del Sacro Cuore di Milano, Italy.
    Biassoni, Federica
    Università Cattolica del Sacro Cuore di Milano, Italy.
    Lombardi, Debora
    Università Cattolica del Sacro Cuore di Milano, Italy.
    Perego, Paolo
    Università Cattolica del Sacro Cuore di Milano, Italy.
    Reaction Time Variability Association with Safe Driving IndexesIngår i: Transport Research Arena TRA2020, Helsinki, FinlandKonferensbidrag (Refereegranskat)
    Abstract [en]

    Naturalistic Driving Study (NDS) is a research area that is potential for collecting data on driver performance, i.e. behavior in normal, impaired and risky situations based on human factors. This work investigates results of a cognitive assessment tests targeting different human factors including visual field, reaction speed, driving behavior and personality traits of drivers in an NDS. Frequency of being involved in Near Miss event (fnm) and Frequency of committing Traffic Violation (fv) are defined as indexes of safe driving in this work. Inference of association shows statistically significant correlation between Standard Deviation of Reaction Time (σRT) and both safe driving indexes fnm and fv. Causal relationship analysis excludes age as confounding factor as variations in behavioral responses is observed in both younger and older drivers of this study.

  • 57.
    Altenbernd, Peter
    et al.
    University of Applied Sciences Darmstadt, Germany.
    Ermedahl, Andreas
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Lisper, Björn
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Gustafsson, Jan
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Automatic Generation of Timing Models for Timing Analysis of High-Level Code2011Ingår i: 19th International Conference on Real-Time and Network Systems (RTNS2011), 2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    Traditional timing analysis is applied only in the late stages of embedded system software development, when the hardware is available and the code is compiled and linked. However, preliminary timing estimates are often needed already in early stages of system development, both for hard and soft real-time systems. If the hardware is not yet fully accessible, or the code is not yet ready to compile or link, then the timing estimation must be done for the source code rather than for the binary. This paper describes how source-level timing models can be derived automatically for given combinations of hardware architecture and compiler. The models are identified from measured execution times for a set of synthetic "training programs" compiled for the hardware platform in question. The models can be used to derive source-level WCET estimates, as well as for estimating the execution times for single program runs. Our experiments indicate that the models can predict the execution times of the final, compiled code with a deviation up to 20%.

  • 58.
    Altenbernd, Peter
    et al.
    University of Applied Sciences, Germany.
    Gustafsson, Jan
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lisper, Björn
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Stappert, Friedhelm
    Siemens VDO Automotive AG, Germany.
    Early execution time-estimation through automatically generated timing models2016Ingår i: Real-time systems, ISSN 0922-6443, E-ISSN 1573-1383, Vol. 52, nr 6, s. 731-760Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Traditional timing analysis, such as worst-case execution time analysis, is normally applied only in the late stages of embedded system software development, when the hardware is available and the code is compiled and linked. However, preliminary timing estimates are often needed in early stages of system development as an essential prerequisite for the configuration of the hardware setup and dimensioning of the system. During this phase the hardware is often not available, and the code might not be ready to link. This article describes an approach to predict the execution time of software through an early, source-level timing analysis. A timing model for source code is automatically derived from a given combination of hardware architecture and compiler. The model is identified from measured execution times for a set of synthetic training programs, compiled for the hardware platform in question. It can be used to estimate the execution time for code running on the platform: the estimation is then done directly from the source code, without compiling and running it. Our experiments show that, using this model, we can predict the execution times of the final, compiled code surprisingly well. For instance, we achieve an average deviation of 8 % for a set of benchmark programs for the ARM7 architecture.

  • 59.
    Alvaro, Alexandre
    et al.
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Land, Rikard
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Crnkovic, Ivica
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Software Component Evaluation: A Theoretical Study on Component Selection and Certification2007Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Software components need to be evaluated at several points during their life cycle, by different actors and for different purposes. Besides the quality assurance performed by component developers, there are two main activities which include evaluation of components: component selection (i.e. evaluation performed by the system developer in order to select the best fit component to use in a system) and an envisioned component certification (i.e. evaluation made by an independent actor in order to increase the trust in the component). This paper examines the fundamental similarities and differences between these two types of component evaluations and elaborates how these fit in the overall process views of component-based development for both COTS-based development and software product line development.

  • 60.
    Andersson, Johan
    et al.
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Huselius, Joel
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Norström, Christer
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Wall, Anders
    Mälardalens högskola, Institutionen för datavetenskap och elektronik. ABB Corporate Research, Västerås, Sweden.
    Extracting Simulation Models from Complex Embedded Real-Time Systems2006Ingår i: Proceedings of the 2006 International Conference on Software Engineering Advances, ICSEA'06, Tahiti, French Polynesia, 2006, s. Article number 4031792-Konferensbidrag (Refereegranskat)
    Abstract [en]

    A modeling process is presented for extracting timingaccurate simulation models from complex embedded real-time systems. The process is supported by two complementary methods for tool-supported model extraction, Model Synthesis and Hybrid Model Extraction. The generated models enable impact analysis for complex real-time systems with respect to dynamic system properties, such as timing and resource usage. This can make software maintenance more predictable with respect to time-to-market and development costs, since timing errors can be identified early and avoided. The contribution of the paper is the modeling process, the Hybrid Model Extraction method and an interactive modeling tool, MASS, designed to support Hybrid Model Extraction of large implementations in C.

  • 61.
    Andersson, Johan
    et al.
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Wall, Anders
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Norström, Christer
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    A Framework for Analysis of Timing and Resource Utilization targeting Complex Embedded Systems2006Ingår i: ARTES - A network for Real-Time research and graduate Education in Sweden 1997 - 2006, Uppsala: Department of Information Technology , 2006, s. 297-329Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    A problem in common of many complex software systems embedded in industrial

    products is the absence of analyzability as formal models of the system

    behavior does not exist. When performing maintenance of such systems it is

    hard to predict how changes will impact specific system properties related to

    timing and resource utilization and there is therefore a significant risk of running

    into problems with unexpected side-effects of the changes made, which

    increases development time required and costs.

    In this paper we present the ART Framework, a set of methods and tools

    that enable behavior impact analysis for existing industrial real-time systems.

    The ART Framework enables developers of complex software systems to identify

    problematic side-effects of a proposed design before vast resources have

    been invested in implementation and testing. This reduces the risk of expensive

    and time-consuming problems discovered late in a development project

    and also reduces the risk releasing software containing latent critical errors.

  • 62.
    Aravind, Meera
    et al.
    Mälardalens högskola.
    Wiklander, G.
    Uppsala University, Uppsala, Sweden.
    Palmheden, J.
    Scania AB, Södertälje, Sweden.
    Dobrin, Radu
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    An Event-Based Messaging Architecture for Vehicular Internet of Things (IoT) Platforms2017Ingår i: Communications in Computer and Information Science, vol. 778, Springer Verlag , 2017, s. 37-46Konferensbidrag (Refereegranskat)
    Abstract [en]

    Internet of Things (IoT) has revolutionized transportation systems by connecting vehicles consequently enabling their tracking, as well as monitoring of driver activities. Such an IoT platform requires a significant amount of data to be send from the on-board vehicle to the off-board servers, contributing to high network usage. The data can be send at regular intervals or in an event-based manner whenever relevant events occur. In interval-based approach, the data is send even if it is not relevant for reporting leading to a wastage of network resources, e.g., when the data does not change considerably compared to the previously sent value. In this paper, we investigate the possibility of using an event-based architecture to send data from the on-board system to the off-board system. The results show that our event-based architecture improves the accuracy of data available at the off-board system, by a careful selection of events. Moreover, we found that our event based architecture significantly decreases the frequency of sending messages, particularly during highway driving, leading to reduced average data transfer rates. Our results enable a customer to perform trade-offs between accuracy and data transfer rates. 

  • 63. Argunsah, Ali Özgur
    et al.
    Çürüklü, Baran
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Cetin, Mujdat
    Detection of Eye Blinks from EEG using Hidden Markov Models2009Konferensbidrag (Refereegranskat)
  • 64.
    Ashjaei, Mohammad
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Behnam, Moris
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Almeida, Luis
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. University of Porto, Porto, Portugal .
    Nolte, Thomas
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    MTU Configuration for Real-Time Switched Ethernet Networks2016Ingår i: Journal of systems architecture, ISSN 1383-7621, E-ISSN 1873-6165, Vol. 70, s. 15-25Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, we show that in real-time switched Ethernet networks reducing the Maximum Transmission Unit (MTU) size may cause an increase or decrease in the response time of messages. This contradicting behavior arises an optimization problem for configuring the MTU size. We formulate the optimization problem in the context of the multi-hop HaRTES architecture, which is a hard real-time Ethernet protocol. As part of the solution, we propose a search-based algorithm to achieve optimum solutions. We modify the algorithm by presenting two techniques to reduce the search space. Then, we propose a heuristic algorithm with a pseudo-polynomial time complexity based on the search-based algorithm. We perform several experiments, and we show that the proposed heuristic results in an improvement regarding messages response times, compared with configuring the MTU to the maximum or minimum values. Moreover, we show in small network configurations that the heuristic performs as good as the search-based algorithm in many cases.

  • 65.
    Ashjaei, Mohammad
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Du, Yong
    Almeida, L.
    University of Porto, Porto, Portugal .
    Behnam, Moris
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Nolte, Thomas
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Dynamic reconfiguration in HaRTES switched ethernet networks2016Ingår i: IEEE International Workshop on Factory Communication Systems - Proceedings, WFCS, 2016, artikel-id Article number 7496510Konferensbidrag (Refereegranskat)
    Abstract [en]

    The ability of reconfiguring a system during runtime is essential for dynamic real-time applications in which resource usage is traded online for quality of service. The HaRTES switch, which is a modified Ethernet switch, holds this ability for the network resource, and at the same time it provides hard real-time support for both periodic and sporadic traffic. Although the HaRTES switch technologically caters this ability, a protocol to actually perform the dynamic reconfiguration is missing in multi-hop HaRTES networks. In this paper we introduce such a protocol that is compatible with the traffic scheduling method used in the architecture. We prove the correctness of the protocol using a model checking technique. Moreover, we conduct a set of simulation experiments to show the performance of the protocol and we also show that the reconfiguration process is terminated within a bounded time. 

  • 66.
    Ashjaei, Mohammad
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Khalilzad, Nima
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Mubeen, Saad
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. IS (Embedded Systems).
    Behnam, Moris
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Sander, Ingo
    Royal Institute of Technology, Sweden.
    Almeida, Luis
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Nolte, Thomas
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Designing End-to-end Resource Reservations in Predictable Distributed Embedded Systems2017Ingår i: Real-time systems, ISSN 0922-6443, E-ISSN 1573-1383, Vol. 53, nr 6, s. 916-956Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Contemporary distributed embedded systems in many domains have become highly complex due to ever-increasing demand on advanced computer controlled functionality. The resource reservation techniques can be effective in lowering the software complexity, ensuring predictability and allowing flexibility during the development and execution of these systems. This paper proposes a novel end-to-end resource reservation model for distributed embedded systems. In order to support the development of predictable systems using the proposed model, the paper provides a method to design resource reservations and an end-to-end timing analysis. The reservation design can be subjected to different optimization criteria with respect to runtime footprint, overhead or performance. The paper also presents and evaluates a case study to show the usability of the proposed model, reservation design method and end-to-end timing analysis. 

  • 67.
    Ashjaei, Mohammad
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Mubeen, Saad
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Behnam, Moris
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Almeida, Luis
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Nolte, Thomas
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    End-to-end Resource Reservations in Distributed Embedded Systems2016Ingår i: Proceedings - 2016 IEEE 22nd International Conference on Embedded and Real-Time Computing Systems and Applications, RTCSA 2016, 2016, s. 1-11, artikel-id 7579921Konferensbidrag (Refereegranskat)
    Abstract [en]

    The resource reservation techniques provide effective means to lower the software complexity, ensure predictability and allow flexibility during the development and execution of complex distributed embedded systems. In this paper we propose a new end-to-end resource reservation model for distributed embedded systems. The model is comprehensive in such a way that it supports end-to-end resource reservations on distributed transactions with various activation patterns that are commonly used in industrial control systems. The model allows resource reservations on processors and real-time network protocols. We also present timing analysis for the distributed embedded systems that are developed using the proposed model. The timing analysis computes the end-to-end response times as well as delays such as data age and reaction delays. The presented analysis also supports real-time networks that can autonomously initiate transmissions. Such networks are not supported by the existing analyses. We also include a case study to show the usability of the model and end-to-end timing analysis with resource reservations.

  • 68.
    Ashjaei, Mohammad
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Patti, Gaetano
    University of Catania, Italy.
    Behnam, Moris
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Nolte, Thomas
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Alderisi, Giuliana
    University of Catania, Italy.
    Lo Bello, Lucia
    University of Catania, Italy.
    Schedulability Analysis of Ethernet Audio Video Bridging Networks with Scheduled Traffic Support2017Ingår i: Real-time systems, ISSN 0922-6443, E-ISSN 1573-1383, Vol. 53, nr 4, s. 526-577Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The IEEE Audio Video Bridging (AVB) technology is nowadays under consideration in several automation domains, such as, automotive, avionics, and industrial communications. AVB offers several benefits, such as open specifications, the existence of multiple providers of electronic components, and the real-time support, as AVB provides bounded latency to real-time traffic classes. In addition to the above mentioned properties, in the automotive domain, comparing with the existing in-vehicle networks, AVB offers significant advantages in terms of high bandwidth, significant reduction of cabling costs, thickness and weight, while meeting the challenging EMC/EMI requirements. Recently, an improvement of the AVB protocol, called the AVB ST, was proposed in the literature, which allows for supporting scheduled traffic, i.e., a class of time-sensitive traffic that requires time-driven transmission and low latency. In this paper, we present a schedulability analysis for the real-time traffic crossing through the AVB ST network. In addition, we formally prove that, if the bandwidth in the network is allocated according to the AVB standard, the schedulability test based on response time analysis will fail for most cases even if, in reality, these cases are schedulable. In order to provide guarantees based on analysis test a bandwidth over-reservation is required. In this paper, we propose a solution to obtain a minimized bandwidth over-reservation. To the best of our knowledge, this is the first attempt to formally spot the limitation and to propose a solution for overcoming it. The proposed analysis is applied to both the AVB standard and the AVB ST. The analysis results are compared with the results of several simulative assessments, obtained using OMNeT++, on both automotive and industrial case studies. The comparison between the results of the analysis and the simulation ones shows the effectiveness of the analysis proposed in this work.

  • 69.
    Ashjaei, Seyed Mohammad Hossein
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Clegg, Kester
    Univ York, York, N Yorkshire, England..
    Corneo, Lorenzo
    Uppsala Univ, Uppsala, Sweden..
    Hawkins, Richard
    Univ York, York, N Yorkshire, England..
    Jaradat, Omar
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Gulisano, Vincenzo Massimiliano
    Chalmers Univ, Gothenburg, Sweden..
    Nikolakopoulos, Yiannis
    Chalmers Univ, Gothenburg, Sweden..
    Service Level Agreements for Safe and Configurable Production Environments2018Ingår i: 2018 IEEE 23RD INTERNATIONAL CONFERENCE ON EMERGING TECHNOLOGIES AND FACTORY AUTOMATION (ETFA), IEEE , 2018, s. 1252-1255Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper focuses on Service Level Agreements (SLAs) for industrial applications that aim to port some of the control functionalities to the cloud. In such applications, industrial requirements should be reflected in SLAs. In this paper, we present an approach to integrate safety-related aspects of an industrial application to SLAs. We also present the approach in a use case. This is an initial attempt to enrich SLAs for industrial settings to consider safety aspects, which has not been investigated thoroughly before.

  • 70.
    Ashjaei, Seyed Mohammad Hossein
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Clegg, Kester
    University of York, UK.
    Corneo, Lorenzo
    Uppsala University, Sweden.
    Hawkins, Richard
    University of York, UK.
    Jaradat, Omar
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Gulisano, Vincenzo
    Chalmers University of Technology, Göteborg, Sweden.
    Nikolakopoulos, Yiannis
    Chalmers University of Technology, Göteborg, Sweden.
    Service Level Agreements for Safe and Configurable Production Environments2018Ingår i: International Conference on Emerging Technologies and Factory Automation - Work in Progress Session ETFA-WiP'18, 2018, s. 1252-1255, artikel-id 8502568Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper focuses on Service Level Agreements (SLAs) for industrial applications that aim to port some of the control functionalities to the cloud. In such applications, industrial requirements should be reflected in SLAs. In this paper, we present an approach to integrate safety-related aspects of an industrial application to SLAs. We also present the approach in a use case. This is an initial attempt to enrich SLAs for industrial settings to consider safety aspects, which has not been investigated thoroughly before.

  • 71.
    Ashjaei, Seyed Mohammad Hossein
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Khalilzad, Nima
    Qamcom Research and Technology, Stockholm, Sweden.
    Mubeen, Saad
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Modeling, Designing and Analyzing Resource Reservations in Distributed Embedded Systems2018Ingår i: Real-Time Modelling and Processing for Communication Systems / [ed] Springer, Springer , 2018, s. 203-256Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 72.
    Ashjaei, Seyed Mohammad Hossein
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Mubeen, Saad
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lundbäck, John
    Arcticus Systems AB, Sweden.
    Gålnander, Mattias
    Arcticus Systems AB, Sweden.
    Lundbäck, Kurt-Lennart
    Arcticus Systems AB, Sweden.
    Nolte, Thomas
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Modeling and Timing Analysis of Vehicle Functions Distributed over Switched Ethernet2017Ingår i: IECON 2017 - 43RD ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY, 2017, s. 8419-8424Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper proposes an approach to model switched Ethernet communication within a model- and component-based software development framework for vehicular distributed embedded systems. The paper also presents a method to extract the network timing model from the systems that use switched Ethernet networks. In order to provide a proof of concept, an existing industrial component model and its tool suite, namely RCM and Rubus-ICE respectively, are extended by implementing the modeling technique, the timing model extraction method and response-time analysis of the Ethernet AVB protocol. The extensions to RCM are backward compatible with the modeling and end-to-end timing analysis of traditional in-vehicle networks and legacy (previously developed) vehicular distributed embedded systems. Furthermore, the paper discusses the implementation and test strategy used in this work. Finally, the usability of the modeling approach and implemented timing analysis is demonstrated by modeling and time analyzing a vehicular application case study with the extended component model and tool suite.

  • 73.
    Aslam, Mudassar
    Mälardalens högskola, Akademin för innovation, design och teknik. Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Bringing Visibility in the Clouds: using Security, Transparency and Assurance Services2014Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The evolution of cloud computing allows the provisioning of IT resources over the Internet and promises many benefits for both - the service users and providers. Despite various benefits offered by cloud based services, many users hesitate in moving their IT systems to the cloud mainly due to many new security problems introduced by cloud environments. In fact, the characteristics of cloud computing become basis of new problems, for example, support of third party hosting introduces loss of user control on the hardware; similarly, on-demand availability requires reliance on complex and possibly insecure API interfaces; seamless scalability relies on the use of sub-providers; global access over public Internet exposes to broader attack surface; and use of shared resources for better resource utilization introduces isolation problems in a multi-tenant environment. These new security issues in addition to existing security challenges (that exist in today's classic IT environments) become major reasons for the lack of user trust in cloud based services categorized in Software-as-a-Service (SaaS), Platform-as-a-Service (PaaS) or Infrastructure-as-a-Service (IaaS).

    The focus of this thesis is on IaaS model which allows users to lease IT resources (e.g. computing power, memory, storage, etc.) from a public cloud to create Virtual Machine (VM) instances. The public cloud deployment model considered in this thesis exhibits most elasticity (i.e. degree of freedom to lease/release IT resources according to user demand) but is least secure as compared to private or hybrid models. As a result, public clouds are not trusted for many use cases which involve processing of security critical data such as health records, financial data, government data, etc. However, public IaaS clouds can also be made trustworthy and viable for these use cases by providing better transparency and security assurance services for the user. In this thesis, we consider such assurance services and identify security aspects which are important for making public clouds trustworthy. Based upon our findings, we propose solutions which promise to improve cloud transparency thereby realizing trustworthy clouds.

    The solutions presented in this thesis mainly deal with the secure life cycle management of the user VM which include protocols and their implementation for secure VM launch and migration. The VM launch and migration solutions ensure that the user VM is always hosted on correct cloud platforms which are setup according to a profile that fulfills the use case relevant security requirements. This is done by using an automated platform security audit and certification mechanism which uses trusted computing and security automation techniques in an integrated solution. In addition to provide the assurance about the cloud platforms, we also propose a solution which provides assurance about the placement of user data in correct and approved geographical locations which is critical from many legal aspects and usually an important requirement of the user. Finally, the assurance solutions provided in this thesis increase cloud transparency which is important for user trust and to realize trustworthy clouds.

  • 74.
    Asplund, Lars
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Lundqvist, Kristina
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Safety Critical Systems Based on Formal Models2000Ingår i: ACM SIGAda Letters, ISSN 1094-3641, Vol. XX, nr 4, s. 32-39Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Ravenscar profile for high integrity systems using Ada 95 is well defined in all real-time aspects. The complexity of the run-time system has been reduced to allow full utilization of formal methods for applications using the Ravenscar profile. In the Mana project a tool set is being developed including a formal model of a Ravenscar compliant run-time system, a gnat compatible run-time system, and an ASIS based tool to allow for the verification of a system including both COTS and code that is reused.

  • 75.
    Asplund, Lars
    et al.
    Uppsala University, Sweden.
    Lundqvist, Kristina
    Massachusetts Institute of Technology, USA.
    Safety Critical Systems Based on Formal Models2000Ingår i: ACM SIGAda Ada Letters - special issue on presentations from SIGAda 2000, Vol. XX, Iss. 4, 2000Konferensbidrag (Övrigt vetenskapligt)
  • 76.
    Asplund, Lars
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Lundqvist, Kristina
    MIT, Cambridge, MA, United States .
    The Gurkh Project: A Framework for Verification and Execution of Mission Critical Applications2003Ingår i: AIAA/IEEE Digital Avionics Systems Conference - Proceedings, vol. 2, 2003, s. 10.B.1/1-10.B.1/9Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    The paper contributes with three methods that together will make a complete tool-set for verification of mission critical applications. The first method is the transformation of existing Ada or VHDL code into an intermediate form. This form is used for verification by numerous different model checkers. The second method is a predictable runtime kernel that has both a verifiable formal model and is implemented in hardware to achieve full predictability. Finally, a method for transforming the intermediate form of the complete system into a hardware unit, the SafetyChip that performs runtime control of the system. This SafetyChip can catch 'out-of-state' behaviors.

  • 77. Avdagic, Zikrija
    et al.
    Boskovic, Dusanka
    Causevic, Aida
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Code Evaluation Using Fuzzy Logic2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents application of a fuzzy logic based system to automatically evaluate the

    maintainability of code. Code evaluation is accomplished by rating its quality provided with bad smells in

    code as inputs. Straightforward bad smells with existing software metrics tools are selected as inputs:

    duplicated code, long methods, large classes having a high cyclomatic complexity, or a large number of

    parameters and temporary fields. Removing these bad smells can result in significant code improvements

    concerning readability and maintainability. However, the precise definition of attributes like small, long, large

    or high is not clear, and their identification is rather subjective. Fuzzy logic values are suitable for capturing

    partial correspondence to attributes and fuzzy rules model have been used to describe the relation between bad

    smells and code quality. Model supporting the experimental evaluation of the fuzzy based code evaluation is

    implemented in Java.

    Key-Words: - Fuzzy Logic, Reasoning Systems, Refactoring, Bad Smells

  • 78.
    Avritzer, A
    et al.
    Siemens Corporate Research, USA.
    Weyuker, Elaine
    AT and T Labs - Research, USA.
    The Automated Generation of Test Cases using an Extended Domain Based Reliability Model2009Ingår i: Proceedings of the 2009 ICSE Workshop on Automation of Software Test, AST 2009, 2009, s. 44-52, artikel-id 5069040Konferensbidrag (Refereegranskat)
  • 79.
    Awada, Imad Alex
    et al.
    University Politehnica of Bucharest, Romania.
    Cramariuc, Oana
    IT Cenetr for Science and Technology, Romania.
    Mocanu, Irina
    University Politehnica of Bucharest.
    Seceleanu, Cristina
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Kunnappilly, Ashalatha
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Florea, Adina Magda
    University Politehnica of Bucharest, Romania.
    An end- user perspective on the CAMI Ambient and Assisted Living Project2018Ingår i: INTED2018 Proceedings, 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we present the outcomes and conclusions obtained by involving seniors from three countries (Denmark, Poland and Romania) in an innovative project funded under the European Ambient Assisted Living (ALL) program. CAMI stands for "Companion with Autonomously Mobile Interface" in "Artificially intelligent ecosystem for self-management and sustainable quality of life in AAL". The CAMI solution enables flexible, scalable and individualised services that support elderly to self-manage their daily life and prolong their involvement in the society (sharing knowledge, continue working, etc). This also allows their informal caregivers (family and friends) to continue working and participating in society while caring for their loved ones. The solution is designed as an innovative architecture that allows for individualized, intelligent self-management which can be tailored to an individual's preferences and needs. A user-centred approach has ranked health monitoring, computer supervised physical exercises and voice based interaction among the top favoured CAMI functionalities. Respondents from three countries (Poland, Romania and Denmark) participated in a multinational survey and a conjoint analysis study.

  • 80.
    Axelsson, Jakob
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    A refined terminology on system-of-systems substructure and constituent system states2019Ingår i: 2019 14th Annual Conference System of Systems Engineering, SoSE 2019, Institute of Electrical and Electronics Engineers Inc. , 2019, s. 31-36Konferensbidrag (Refereegranskat)
    Abstract [en]

    In the field of systems-of-systems (SoS) engineering, there is broad agreement on a few characterizations, and these are currently being standardized. However, many aspects in the field still lack an established terminology. In particular, there are unclarities related to the internal structure of an SoS, and on the internal states of constituent systems. In this paper, a refined terminology is therefore proposed, which covers the internal substructure of an SoS; the states of constituent systems in relation to those substructures; and how it relates to hierarchical levels. This terminology can also be used to classify the characteristics of an SoS through different metrics. The terminology is illustrated through three examples of SoS applications in various domains. 

  • 81.
    Axelsson, Jakob
    Software and Systems Engineering Laboratory, Swedish Institute of Computer Science (SICS), Kista, Sweden .
    A Systematic Mapping of the Research Literature on System-of-Systems Engineering2015Ingår i: 10th Annual Systems of Systems Engineering Conference SOSE, 2015, s. 18-23Konferensbidrag (Refereegranskat)
    Abstract [en]

    The research area systems-of-systems engineering has increased rapidly over the last decade and now contains a substantial body of literature. To get an overview of the field, a systematic mapping of the literature has been done, covering over 3000 papers. It revealed a field massively dominated by US researchers, with an emphasis on military and space systems. A large number of people are involved, but few researchers focus on the area, and citations are fairly low compared to other fields. Important research topics include architecture, modeling and simulation, integration and interoperability, communication, sustainability, and safety and security. There are signs of immaturity within the research area, and it is recommended that existing venues are complemented with an international scientific event with very high standards for submissions.

  • 82.
    Axelsson, Jakob
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. RISE Research Institutes of Sweden, Kista, Sweden.
    An initial analysis of operational emergent properties in a platooning system-of-systems2018Ingår i: 12th Annual IEEE International Systems Conference, SysCon 2018 - Proceedings, Institute of Electrical and Electronics Engineers Inc. , 2018, s. 1-8Konferensbidrag (Refereegranskat)
    Abstract [en]

    As systems-of-systems start to be more common in commercial applications, an analysis of emergent properties related to utility and cost for all stakeholders becomes critical. This paper describes an approach for this based on network simulation and game theory, which is applied to truck highway platooning. The emergent properties of energy efficiency and transport efficiency are studied as a consequence of the strategies for platoon formation, and it is shown that having information about the route planning of other vehicles has a significant positive effect on the properties. This indicates the need for a mediator in the platooning system-of-systems architecture. Its role is to communicate plans of the constituent systems.

  • 83.
    Axelsson, Jakob
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Architectural Allocation Alternatives and Associated Concerns in Cyber-Physical Systems: A Case Study2015Ingår i: ECSAW '15 Proceedings of the 2015 European Conference on Software Architecture Workshops, 2015, Vol. Article No.15Konferensbidrag (Refereegranskat)
    Abstract [en]

    Cyber-physical systems is an extension of traditional embedded systems, where communication to the outside world is given more emphasis. This leads to a new design space also for software development, allowing new allocation strategies for functionality. In traditional embedded systems, all functionality was inside the product, but now it becomes possible to partition the software between the embedded systems and IT systems outside the product. This paper investigates, through a case study from the automotive domain, possible new allocation alternatives where computation is offloaded from the embedded system to a server, and what additional architectural concerns this leads to, including performance, resource utilization, robustness, and lifecycle aspects. In addition, the paper addresses new opportunities created by allocating functionality outside the embedded systems, and thus making data available for extended services, as well as the larger concerns that result on the organizational level, including new competency in architecture and DevOps.

  • 84.
    Axelsson, Jakob
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Business models and roles for mediating services in a truck platooning system-of-systems2019Ingår i: 2019 14th Annual Conference System of Systems Engineering, SoSE 2019, Institute of Electrical and Electronics Engineers Inc. , 2019, s. 113-118Konferensbidrag (Refereegranskat)
    Abstract [en]

    Platooning of trucks on motorways has been proposed as a method of reducing fuel consumption. It requires communication between the trucks to control the distance between them. However, this system-of-systems (SoS) cannot only contain the trucks, but also needs to include mediating off-board services for match-making to find suitable constellations of trucks, and for creating platooning incentives by distributing the profit made equally among the constituent systems. This paper analyzes what actors in the SoS would be suitable to operate these services, and also business models that cover the cost for their implementation and operation. It concludes that the truck OEMs have a vital role in creating the mediating services, and that a suitable business model would be based on usage fees for the services rather than upfront payment for platooning equipment. 

  • 85.
    Axelsson, Jakob
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Experiences of Using Linked Data and Ontologies for Operational Data Sharing in Systems-of-Systems2019Ingår i: 13th Annual IEEE International Systems Conference SysCon2019, Orlando, Florida, United States, 2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper addresses the problem of exchanging complex data between the constituent systems in a system-of-systems. This is necessary to ensure that they have compatible understandings of the world surrounding them and entails a need for semantic interoperability between the constituents. Through a case study of a road construction system-of-systems, the world wide web technologies of linked data and ontologies are explored as a framework for data representation and exchange. This data includes several broad categories, such as assets, interfaces, organizations, capabilities, missions, and observations, as well as various properties of those. It is also discussed how the constituents can use this data for reasoning and decision making. The results have been validated through a simulation-based research prototype of the road construction case, from which experiences are reported.

  • 86.
    Axelsson, Jakob
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. RISE Research Institutes of Sweden, Sweden.
    Game Theory Applications in Systems-of-Systems Engineering: A Literature Review and Synthesis2019Ingår i: Procedia Computer Science, ISSN 1877-0509, E-ISSN 1877-0509, Vol. 153, s. 154-165Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Systems-of-systems (SoS) are becoming increasingly common in more and more domains, spreading from the initial focus on government-controlled areas such as defense to open market industries. This implies that collaborative SoS are becoming more important, where the constituents need to be given incentives to join and remain within the SoS. Game theory has been proposed as a framework to model and analyze such SoS mechanisms. It aims at providing such incentives to the independently operated and managed constituents. This paper presents a systematic literature review on the applications of game theory to SoS engineering, together with a synthesis aiming at capturing the best practices for such an analysis. The main conclusions are that game theory can be applied to SoS in a wide range of application areas, and deal with problems related to acquisition, design, and operations. In particular, the operational formation of SoS are well suited for this kind of analysis, and this often requires the use of simulation techniques. However, most results in the field lack a validation in practice.

  • 87.
    Axelsson, Jakob
    et al.
    Swedish Institute of Computer Science, SICS, Sweden.
    Franke, Ulrik
    Swedish Institute of Computer Science, SICS, Sweden.
    Carlson, Jan
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Sentilles, Séverine
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Cicchetti, Antonio
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Towards the Architecture of a Decision Support Ecosystem for System Component Selection2017Ingår i: 11th Annual IEEE International Systems conference SysCon17, 2017, s. 371-377Konferensbidrag (Refereegranskat)
    Abstract [en]

    When developing complex software-intensive systems, it is nowadays common practice to base the solution partly on existing software components. Selecting which components to use becomes a critical decision in development, but it is currently not well supported through methods and tools. This paper discusses how a decision support system for this problem could benefit from a software ecosystem approach, where participants share knowledge across organizations both through reuse of analysis models, and through partially disclosed past decision cases. It is shown how the architecture of this ecosystem becomes fundamental to deal with efficient knowledge sharing, while respecting constraints on integrity of intellectual property. A concrete proposal for an architecture is outlined, which is a distributed system-of-systems using web technologies. Experiences of a proof-of-concept implementation are also described.

  • 88.
    Axelsson, Jakob
    et al.
    RISE SICS AB, Kista, Sweden.
    Nylander, Stina
    RISE SICS AB, Kista, Sweden.
    An Analysis of Systems-of-Systems Opportunities and Challenges Related to Mobility in Smart Cities2018Ingår i: System of Systems Engineering Conference SoSE 2018, 2018, s. 132-137Konferensbidrag (Refereegranskat)
    Abstract [en]

    Urbanization is one of the major current trends in society. Cities around the world are looking into 'smart'  solutions based on information and communication technology to deal with the challenges that result from this development. Mobility is one of the most important areas to address, and system-of-systems solutions where vehicles and infrastructure are connected have a potential to improve urban transportation in many aspects. In this paper, current initiatives related to mobility in smart cities around the world are surveyed, and this is complemented with input from focus groups of transportation stakeholders to identify the important aspects of the problem. Based on this, challenges related to the application of systems-of-systems in urban mobility are identified.

  • 89.
    Axelsson, Jakob
    et al.
    SICS Swedish ICT, Sweden.
    Papatheocharous, Efi
    SICS Swedish ICT, Sweden.
    Nyfjord, Jaana
    SICS Swedish ICT, Sweden.
    Törngren, Martin
    KTH Royal Institute of Technology, Sweden.
    Notes On Agile and Safety-Critical Development2016Ingår i: Software Engineering Notes: an Informal Newsletter of The Specia, ISSN 0163-5948, E-ISSN 1943-5843, Vol. 41, nr 2, s. 23-26Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Agile approaches have been highly influential to the software engineering practices in many organizations, and are increasingly being applied in larger companies, and for developing systems outside the pure software domain. To understand more about the current state of agile, its applications to safety-critical systems, and the consequences on innovation and large organizations, a seminar was organized in Stockholm in 2014. This paper gives an overview of the topics discussed at that seminar, a summary of the main results and suggestions for future work as input to a research agenda for agile development of safety-critical software.

  • 90.
    Ayala, Inmaculada
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Gallina, Barbara
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Towards Tool-based Security-informed Safety Oriented Process Line Engineering2016Ingår i: 1st International workshop on Interplay of Security, Safety and System/Software Architecture ISSA-2016, 2016, artikel-id 38Konferensbidrag (Refereegranskat)
    Abstract [en]

    For the purpose of certification, manufactures of nowadays highly connected safety-critical systems are expected to en- gineer their systems according to well-defined engineering processes in compliance with safety and security standards. Certification is an extremely expensive and time-consuming process. Since safety and security standards exhibit a certain degree of commonality, certification-related artifacts (e.g., process models) should to some extent be reusable. To en- able systematic reuse and customization of process infor- mation, in this paper we further develop security-informed safety-oriented process line engineering (i.e., engineering of sets of processes including security and safety concerns). More specifically, first we consider three tool-supported ap- proaches for process-related commonality and variability man- agement and we apply them to limited but meaningful por- tions of safety and security standards within airworthiness. Then, we discuss our findings. Finally, we draw our conclu- sions and sketch future work.

  • 91.
    Aysan, Hüseyin
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Fault-Tolerance Strategies and Probabilistic Guarantees for Real-Time Systems2012Doktorsavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    Ubiquitous deployment of embedded systems is having a substantial impact on our society, since they interact with our lives in many critical real-time applications. Typically, embedded systems used in safety or mission critical applications (e.g., aerospace, avionics, automotive or nuclear domains) work in harsh environments where they are exposed to frequent transient faults such as power supply jitter, network noise and radiation. They are also susceptible to errors originating from design and production faults. Hence, they have the design objective to maintain the properties of timeliness and functional correctness even under error occurrences.

    Fault-tolerance plays a crucial role towards achieving dependability, and the fundamental requirement for the design of effective and efficient fault-tolerance mechanisms is a realistic and applicable model of potential faults and their manifestations. An important factor to be considered in this context is the random nature of faults and errors, which, if addressed in the timing analysis by assuming a rigid worst-case occurrence scenario, may lead to inaccurate results. It is also important that the power, weight, space and cost constraints of embedded systems are addressed by efficiently using the available resources for fault-tolerance.

    This thesis presents a framework for designing predictably dependable embedded real-time systems by jointly addressing the timeliness and the reliability properties. It proposes a spectrum of fault-tolerance strategies particularly targeting embedded real-time systems. Efficient resource usage is attained by considering the diverse criticality levels of the systems' building blocks. The fault-tolerance strategies are complemented with the proposed probabilistic schedulability analysis techniques, which are based on a comprehensive stochastic fault and error model.

  • 92.
    Aysan, Hüseyin
    et al.
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Dobrin, Radu
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Punnekkat, Sasikumar
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    A Generalized Task Allocation Framework for Dependable Real-Time Systems2007Ingår i: Proceedings of the Work-In-Progress (WIP) session of the 19th Euromicro Conference on Real-Time Systems (ECRTS 07), 2007Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we present a general framework which allows the designer to specify a wide range of criteria for allocation. Major factors considered as part of our framework are mixed criticalities of tasks, schedulability, power consumption, fault-tolerance, and dependability requirements in addition to typical functional aspects such as memory constraints. This being a global optimization problem, we are forced to use meta-heuristic algorithms, and we were able to represent these requirements in a very intuitive manner by the usage of energy functions in simulated annealing. We envision the proposed methodology as a quite simple, scalable, as well as computationally effective solution covering a wide range of system architectures and solution spaces. 

  • 93.
    Aysan, Hüseyin
    et al.
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Dobrin, Radu
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Punnekkat, Sasikumar
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    FT-Feasibility in Fixed Priority Real-Time Scheduling2007Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Real-time systems typically have to satisfy complex requirements mapped to the timing attributes of the tasks that are eventually guaranteed by the underlying scheduler. These systems consist of a mix of hard and soft tasks with varying criticalities as well as associated fault tolerance (FT) requirements. Often time redundancy techniques are preferred in many embedded applications and hence it is extremely important to devise appropriate methodologies for scheduling real-time tasks under fault assumptions. Additionally, the relative criticality of tasks could undergo changes during the evolution of the system. Hence scheduling decisions under fault assumptions have to reflect all these important factors in addition to the resource constraints.

    In this paper we propose a framework for 'FTfeasibility', i.e., to provide a priori guarantees that all critical tasks in the system will meet their deadlines even in case of faults. Our main objective here is to ensure FTfeasibility of all critical tasks in the system and do so with minimal costs and without any fundamental changes in the scheduling paradigm. We demonstrate its applicability in scenarios where the FT strategy employed is re-execution of the affected tasks or an alternate action upon occurrence of transient faults or software design faults. We analyse a feasible set of tasks and propose methods to adapt it to varying FT requirements without modifications to the underlying scheduler. We do so by reassigning task attributes to achieve FT-feasibility while keeping the costs minimised.

  • 94.
    Aysan, Hüseyin
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Punnekkat, Sasikumar
    Mälardalens högskola, Akademin för innovation, design och teknik.
    A Generalised Error Model and Schedulability Guarantees for Dependable Real-Time Systems2011Ingår i: Proceedings of the 1st International Workshop on Dependable and Secure Industrial and Embedded Systems (WORDS), 2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    The fundamental requirement for the design of effective and efficient fault-tolerance mechanisms in dependable real-time systems is a realistic and applicable model of potential faults, their manifestations and consequences. Fault and error models also need to be evolved based on the changes in the environments of usage or even based on technological advances. In this paper we propose a novel probabilistic burst error model in lieu of the commonly used simplistic fault assumptions. We introduce an approach to reason about real-time systems schedulability under the proposed error model in a probabilistic manner. We first present a sufficient analysis that accounts for the worst case interference caused by error bursts on the response times of tasks scheduled under the fixed priority scheduling (FPS) policy. Further, we identify potential sources of pessimism in the calculations and propose an algorithm that refines the results.

  • 95.
    Back, Ralph-Johan
    et al.
    Turku Centre for Computer Science .
    Cerschi (Seceleanu), Cristina
    Turku Centre for Computer Science .
    Modeling and Verifying a Temperature Control System using Continuous Action Systems2000Konferensbidrag (Refereegranskat)
    Abstract [en]

    We formally describe and verify a real-time temperature control system for a nuclear reactor tank, using a generalization of action systems to hybrid systems (based on weakest precondition predicate transformer semantics) as our formal framework. The analyzed control system is a linear hybrid system, combining discrete control with continuous dynamics. Our work can be seen as a case study on the applicability of the hybrid action system formalism to study the reachability problem, i.e., to prove that an unsafe state can not be reached by executing the system.

  • 96.
    Back, Ralph-Johan
    et al.
    Turku Centre for Computer Science, Finland.
    Seceleanu, Cristina
    Turku Centre for Computer Science, Finland.
    Westerholm, Jan
    Turku Centre for Computer Science, Finland.
    Symbolic Simulation of Hybrid Systems2002Konferensbidrag (Refereegranskat)
    Abstract [en]

    Continuous action systems (CAS) is a formalism intended for modeling hybrid systems (systems that combine discrete control with continuous behavior), and proving properties about the model within refinement calculus. In this paper we use a symbolic manipulation program to build a tool for simulating CAS models by calculating symbolically the time evolution of the discrete and continuous CAS model functions, as explicit and exact expressions of a continuous time variable. We may then study the time behavior and general properties of the model by plotting these functions with respect to time. For certain models our tool eliminates the need for introducing tolerances into the model structure. The tool is useful for checking that the model behaves correctly, and we can sometimes study the behavior of CAS models with in principle infinite precision.

  • 97.
    Bagheri, M.
    et al.
    Sharif University of Technology, Tehran, Iran.
    Khamespanah, E.
    Sharif University of Technology, Tehran, Iran.
    Sirjani, Marjan
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. Reykjavik University, Reykjavik, Iceland.
    Movaghar, A.
    Sharif University of Technology, Tehran, Iran.
    Lee, A. E.
    University of California at Berkeley.
    Runtime compositional analysis of track-based traffic control systems2017Ingår i: ACM SIGBED Review, ISSN 1551-3688, Vol. 14, nr 3, s. 38-39Artikel i tidskrift (Refereegranskat)
  • 98.
    Bagheri, M.
    et al.
    Sharif University of Technology, Tehran, Iran.
    Sirjani, Marjan
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. Reykjavik University, Reykjavik, Iceland.
    Khamespanah, E.
    Reykjavik University, Reykjavik, Iceland.
    Khakpour, N.
    Linnaeus University, Växjö Campus, Sweden.
    Akkaya, I.
    University of California at Berkeley, CA, United States.
    Movaghar, A.
    Sharif University of Technology, Tehran, Iran.
    Lee, E. A.
    University of California at Berkeley, CA, United States.
    Coordinated actor model of self-adaptive track-based traffic control systems2018Ingår i: Journal of Systems and Software, ISSN 0164-1212, E-ISSN 1873-1228, Vol. 143, s. 116-139Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Self-adaptation is a well-known technique to handle growing complexities of software systems, where a system autonomously adapts itself in response to changes in a dynamic and unpredictable environment. With the increasing need for developing self-adaptive systems, providing a model and an implementation platform to facilitate integration of adaptation mechanisms into the systems and assuring their safety and quality is crucial. In this paper, we target Track-based Traffic Control Systems (TTCSs) in which the traffic flows through pre-specified sub-tracks and is coordinated by a traffic controller. We introduce a coordinated actor model to design self-adaptive TTCSs and provide a general mapping between various TTCSs and the coordinated actor model. The coordinated actor model is extended to build large-scale self-adaptive TTCSs in a decentralized setting. We also discuss the benefits of using Ptolemy II as a framework for model-based development of large-scale self-adaptive systems that supports designing multiple hierarchical MAPE-K feedback loops interacting with each other. We propose a template based on the coordinated actor model to design a self-adaptive TTCS in Ptolemy II that can be instantiated for various TTCSs. We enhance the proposed template with a predictive adaptation feature. We illustrate applicability of the coordinated actor model and consequently the proposed template by designing two real-life case studies in the domains of air traffic control systems and railway traffic control systems in Ptolemy II. 

  • 99.
    Bagheri, Maryam
    et al.
    Sharif University of Technology, Iran.
    Akkaya, Ilge
    University of California at Berkley, US.
    Khamespanah, Ehsan
    Reykjavik University, Iceland.
    Khakpour, Narges
    Linnaeus University, Sweden.
    Sirjani, Marjan
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Movaghar, Ali
    Sharif University of Technology, Iran.
    Lee, Edward
    University of California at Berkley, US.
    Coordinated Actors for Reliable Self-Adaptive Systems2017Ingår i: The 13th International Conference on Formal Aspects of Component Software FACS 2016, 2017, Vol. 10231, s. 241-259Konferensbidrag (Refereegranskat)
    Abstract [en]

    Self-adaptive systems are systems that automatically adapt in response to environmental and internal changes, such as possible failures and variations in resource availability. Such systems are often realized by a MAPE-K feedback loop, where Monitor, Analyze, Plan and Execute components have access to a runtime model of the system and environment which is kept in the Knowledge component. In order to provide guarantees on the correctness of a self-adaptive system at runtime, the MAPE-K feedback loop needs to be extended with assurance techniques. To address this issue, we propose a coordinated actor-based approach to build a reusable and scalable model@runtime for self-adaptive systems in the domain of track-based traffic control systems. We demonstrate the approach by implementing an automated Air Traffic Control system (ATC) using Ptolemy tool.We compare different adaptation policies on the ATC model based on performance metrics and analyze combination of policies in different configurations of the model. We enriched our framework with runtime performance analysis such that for any unexpected change, subsequent behavior of the model is predicted and results are used for adaptation at the change-point. Moreover, the developed framework enables checking safety properties at runtime.

  • 100.
    Baig, Aftab
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Ahmad, Iftikhar
    Mälardalens högskola, Akademin för innovation, design och teknik.
    A web store based on reusable .NET components2011Självständigt arbete på avancerad nivå (magisterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The thesis project describes  the analysis, process and major factors in development of a simple component oriented Web Shop in ASP.NET. It addresses to the concepts used in  the application as  well  as  derivation  of  technical  design  and  development  from  the  concepts  acquired  by studying existing approaches.

    The report  describes  a  brief  summary of  existing  approaches  and related  technologies.  It also lays  the foundation  of  goal  oriented  approach  by  providing  an  overview  of  component  based  software engineering. The  basic  concepts for modularization  were  barrowed from  entities  identification,  object models and component models pplication’s architecture is set to be a layered app roach combining the software layered  architecture  approach  with  multi  tier  architecture  of  web  applications. Class models explaining the inner structure of each component have been provided and an overview of user interface pages is given to explain the application outer flow. The application sets out to prove the significance of component oriented approach as well as  the  support  provided for it by ASP.Net. The resulting package proves  to  have  scalable  components  that could be scaled for  or  reused in another  application or  in  a later version of the same application. 

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