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  • 1801.
    Zagar, Mario
    et al.
    Univ Zagreb, Fac Elect Engn & Comp, Zagreb, Croatia..
    Crnkovic, Ivica
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Stipanicev, Darko
    Univ Split, Fac Elect Engn Mech Engn & Naval Architecture, Split, Croatia..
    Stula, Maja
    Univ Split, Fac Elect Engn Mech Engn & Naval Architecture, Split, Croatia..
    Feljan, Juraj
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lednicki, Luka
    Univ Zagreb, Fac Elect Engn & Comp, Zagreb, Croatia..
    Maras, Josip
    Univ Split, Fac Elect Engn Mech Engn & Naval Architecture, Split, Croatia..
    Petricic, Ana
    Univ Zagreb, Fac Elect Engn & Comp, Zagreb, Croatia..
    DICES: Distributed Component-based Embedded Software Systems2012Ingår i: ANNUAL 2010/2011 OF THE CROATIAN ACADEMY OF ENGINEERING / [ed] Ziljak, V, CROATIAN ACADEMY ENGINEERING , 2012, s. 154-167Konferensbidrag (Refereegranskat)
    Abstract [en]

    This article gives a short overview of the contribution of DICES project. The goal of the project is to advance theories and technologies used in development of distributed embedded systems. Three examples of the contributions are presented: a) reverse engineering of web based applications, design extraction and extraction of reusable user-interface controls, b) a fretwork for building systems that use UPnP devices and treat them as components in the same way as software components, and c) PRIDE - development environment for designing, modeling and developing embedded systems, based on ProCom technology.

  • 1802.
    Zahid, I.
    et al.
    University of Porto, Porto, Portugal.
    Almeida, L.
    University of Porto, Porto, Portugal.
    Ashjaei, Seyed Mohammad Hossein
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Behnam, Moris
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    On the efficiency of sporadic servers on ethernet with FTT-SE2017Ingår i: SIGBED Review, ISSN 1551-3688, Vol. 14, nr 3, s. 32-34Artikel i tidskrift (Refereegranskat)
  • 1803.
    Zakupszki, Andras
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Pichetpongsa, Nuttapon
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Extending ABB’s WirelessHART Tool2013Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Within this decade, wireless technology has been used in process control in various industries. WirelessHART is one of the standards, used for creating communication networks for such purpose. Since the technology is relatively new, there are many known and unknown risks in deploying it in real life applications.ABB’s WirelessHART Tool is used for generating simulation scenarios that can be used for evaluating the performance of WirelessHART networks under different conditions.This paper describes in detail, how ABB’s WirelessHART Tool was extended by adding various new functionalities. The topics cover what obstacles we have faced, which solutions were used and why, how our solutions were evaluated and the outcomes. Furthermore, the paper documents the application structure of WirelessHART Tool.

  • 1804.
    Zakupszki, Andras
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Pichetpongsa, Nuttapon
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Seceleanu, Tiberiu
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. ABB Corporate Research and Mälardalen University, Västerås, Sweden.
    Scheduling and simulating wireless HART systems2014Ingår i: Proceedings: 40th Euromicro Conference Series on Software Engineering and Advanced Applications, SEAA 2014, 2014, s. 318-319Konferensbidrag (Refereegranskat)
    Abstract [en]

    Control processes and the communication between them must be scheduled appropriately, such that the I/O data is correlated. Here, we illustrate the design and realization of a Wireless HART system development tool, meant to support design decisions in communication and processing scheduling.

  • 1805.
    Zamansky, A.
    et al.
    University of Haifa, Carmel Mountain, Haifa, Israel .
    Rodriguez-Navas, Guillermo
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Adams, M.
    Proof Technologies Ltd., Worcester, United Kingdom.
    Spichkova, M.
    RMIT University, Melbourne, Australia .
    Formal methods in collaborative projects2016Ingår i: ENASE 2016 - Proceedings of the 11th International Conference on Evaluation of Novel Software Approaches to Software Engineering, 2016, s. 396-402Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper we address particular aspects of integration of formal methods in large-scale industrial projects, namely collaborative aspects. We review recent works addressing such aspects, identify some current trends and discuss directions for further research. 

  • 1806.
    Zamansky, A.
    et al.
    University of Haifa, Haifa, Israel.
    Spichkova, M.
    RMIT University, Melbourne, Australia.
    Rodriguez-Navas, Guillermo
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Herrmann, P.
    Norwegian University of Science and Technology, Trondheim, Norway.
    Blech, J. O.
    BHTC GmbH, Lippstadt, Germany.
    Towards classification of lightweight formal methods2018Ingår i: ENASE 2018 - Proceedings of the 13th International Conference on Evaluation of Novel Approaches to Software Engineering, SciTePress , 2018, s. 305-313Konferensbidrag (Refereegranskat)
    Abstract [en]

    The use of lightweight formal methods (LFM) for the development of industrial applications has become a major trend. Although the term “lightweight formal methods” has been used for over ten years now, there seems to be no common agreement on what “lightweight” actually means, and different communities apply the term in all kinds of ways. In this paper, we explore the recent trends in the use of LFM, and establish our opinion that cost-effectiveness is the driving force to deploy LFM. Further, we propose a simple framework that should help to classify different LFM approaches and to estimate which of them are most cost-effective for a certain software engineering project. We demonstrate our framework using some examples. 

  • 1807.
    Zamli, Kamal
    et al.
    Universiti Malaysia Pahang, Malaysia.
    Ahmed, Bestoun
    Czech Technical University, Czech republic.
    Mahmoud, Thair
    Edith Cowan University, Australia.
    Afzal, Wasif
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Fuzzy adaptive tuning of a particle swarm optimization algorithm for variable-strength combinatorial test suite generation2018Ingår i: Swarm Intelligence Volume 3: Applications / [ed] Dr Ying Tan, Institution of Engineering and Technology, 2018Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 1808.
    Zaslansky, R.
    et al.
    Friedrich-Schiller University Hospital, Jena, German.
    Rothaug, J.
    Friedrich-Schiller University Hospital, Jena, German.
    Chapman, R. C.
    University of Utah, Salt Lake City, UT, United States .
    Backström, R.
    University Hospital Örebro, Örebro, Sweden .
    Brill, S.
    Sourasky Medical Center, Tel-Aviv, Israel .
    Engel, C.
    University of Leipzig, Leipzig, Germany.
    Fletcher, D.
    Raymond Poincaré Hospital, Garches, France.
    Fodor, L.
    Cluj University Hospital, Cluj, Romania .
    Funk, Peter
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Gordon, D.
    Harborview Medical Center, Seattle, WA, United States.
    Komann, M.
    Friedrich-Schiller University Hospital, Jena, German.
    Konrad, C.
    Kantonsspital, Lucerne, Switzerland.
    Kopf, A.
    Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany .
    Leykin, Y.
    University of Trieste and Udine, Pordenone, Italy .
    Pogatzki-Zahn, E.
    University Hospital Muenster, Muenster, Germany.
    Puig, M.
    IMIM-Hospital Del Mar-Universitat Autònoma de Barcelona, Barcelona, Spain.
    Rawal, N.
    University Hospital Örebro, Örebro, Sweden.
    Schwenkglenks, M.
    University of Basel, Basel, Switzerland .
    Taylor, R. S.
    University of Exeter, Exeter, United Kingdom .
    Ullrich, K.
    University of London, London, United Kingdom.
    Volk, T.
    Saarland University Hospital, Homburg, Germany.
    Yahiaoui-Doktor, M.
    University of Leipzig, Leipzig, Germany .
    Meissner, W.
    Friedrich-Schiller University Hospital, Jena, German.
    PAIN OUT: An international acute pain registry supporting clinicians in decision making and in quality improvement activities2014Ingår i: Journal of Evaluation In Clinical Practice, ISSN 1356-1294, E-ISSN 1365-2753, Vol. 20, nr 6, s. 1090-1098Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Rationale, aims and objectives Management of post-operative pain is unsatisfactory worldwide. An estimated 240 million patients undergo surgery each year. Forty to 60% of these patients report clinically significant pain. Discrepancy exists between availability of evidence-based medicine (EBM)-derived knowledge about management of perioperative pain and increased implementation of related practices versus lack of improvement in patient-reported outcomes (PROs). We aimed to assist health care providers to optimize perioperative pain management by developing and validating a medical registry that measures variability in care, identifies best pain management practices and assists clinicians in decision making. Methods PAIN OUT was established from 2009 to 2012 with funding from the European Commission. It now continues as a self-sustaining, not-for-profit project, targeting health care professionals caring for patients undergoing surgery. Results The growing registry includes data from 40 898 patients, 60 hospitals and 17 countries. Collaborators upload data (demographics, clinical, PROs) from patients undergoing surgery in their hospital/ward into an Internet-based portal. Two modules make use of the data: (1) online, immediate feedback and benchmarking compares PROs across sites while offline analysis permits in-depth analysis; and (2) the case-based clinical decision support system offers practice-based treatment recommendations for individual patients; it is available now as a prototype. The Electronic Knowledge Library provides succinct summaries on perioperative pain management, supporting knowledge transfer and application of EBM. Conclusion PAIN OUT, a large, growing international registry, allows use of 'real-life' data related to management of perioperative pain. Ultimately, comparative analysis through audit, feedback and benchmarking will improve quality of care.

  • 1809.
    Zetterlund, Samuel
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Blind swimmer detection and notification utilizing OpenCV on the Android platform2013Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    For a blind swimmer to be able to exercise in a swimming pool today, human assistance is required to notifying the swimmer in due time when and if she is too close to the edge. The purpose of this thesis was to see whether or not it is possible to replace and even improve the human intervention using a warning system built around a tablet mounted next to the pool edge. A secondary goal was to evaluate how suitable a tablet pc is for robotic applications. The system proposed utilizes a tablet’s built-in frontal facing camera, OpenCV as vision library, FM modules for the wireless warning system and is intended for the Android environment.

    Videos of the real scenario have been analyzed on a computer using OpenCV and a detection algorithm searching for the swimmer’s red swimming cap has been developed. Next, the algorithm was implemented on an Android tablet. The result obtained shows that it is perfectly possible to use a cheap tablet to accurately detect and notify the blind swimmer in due time when she is too close to the edge. If calibrated thoroughly, the likelihood of a missed detection is actually lower with this system as compared to human intervention, as humans can only warn the swimmer when she is above the water. 

  • 1810.
    Zhang, Shuzhou
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Porting AUTOSAR to a high performance embedded system2013Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Automotive embedded systems are going through a major change, both in terms of how they are used and in terms of software and hardware architecture. Much more powerful and rapidly evolvable hardware is expected, paralleled by an accelerating development rate of the control software. To meet these challenges, a software standard, AUTOSAR, is gaining ground in the automotive field. In this work, experiences from porting AUTOSAR to a high performance embedded system, Raspberry Pi, are collected. The goal is both to present experience on the process of AUTOSAR porting and to create an AUTOSAR implementation on a cheap and widely accessible hardware platform, making AUTOSAR available for researchers and students.

  • 1811.
    Zhao, Xiaosha
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Gan, Lingjian
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Industrial Control Systems On Multi-­‐core2015Självständigt arbete på avancerad nivå (magisterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    In this work, we investigate the challenges that are faced when control systems are shifted from single--‐core processor to multi--‐core processor. Multi--‐core processors have been introduced for their good performance and energy consumption rate. To take advantage of this new solution, in most cases, the industrial applications need to be partitioned into small tasks in order to execute them in parallel on the multi--‐core platform. This transformation brings many benefits to the embedded system as well as challenges to the traditional Task management, such as the deployment of tasks onto different cores, the dependency problem among tasks while executing in parallel, as well as task scheduling and so on. Within this context, we introduce a multi--‐step approach to Deploy control systems applications, which are developed using the IEC61131--‐3 standard, to multi--‐core platforms. Our contribution in this work is that we have developed two engines to enable a smooth transfer. One is called partition engine, which will search a generated C code file and divide it into several separate small tasks. The other one is called deployment engine, which can allocate the divided tasks onto different cores. Based on this approach, we develop a prototype. And the test cases have proved that our approach is very effective and promising for further extension.

  • 1812.
    Zhiqun, Jin
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Shijie, Zhu
    Mälardalens högskola, Akademin för innovation, design och teknik.
    End-to-end Timing Analysis of Task-Chains2017Självständigt arbete på avancerad nivå (magisterexamen), 40 poäng / 60 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Many automotive systems are real-time systems, which means that not only correct operationsbut also appropriate timings are their main requirements. Considering the in uence that end-to-end delay might have on the performance of the systems, the calculation of it is of necessity.Abundant techniques have actually been proposed, and some of them have already been applied intopractical systems. In spite of this, some further work still needs to be done. The target of thisthesis is to evaluate and compare two end-to-end timing analysis methods from dierent aspectssuch as data age, consumption time, and then decide which method is a prior choice for end-to-end timing analysis. The experiments can be divided into three blocks, system generation andend-to-end delay calculation by two methods respectively. The experiments focus on two kinds ofperformance parameters, data age and the consumption time that these two methods cost duringtheir execution. By changing the system generating parameters like task number and periods, thechanges of performances of the two methods are analyzed. The performances of the two dierentmethods are also compared when they are applied into the same automotive systems. According tothe results of the experiments, the second method can calculate more accurate data age and consumeless time than the rst method does.

  • 1813.
    Zhou, Jiale
    Mälardalens högskola, Akademin för innovation, design och teknik. Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    An Observer-Based Technique with Trace Links for Requirements Validation in Embedded Real-Time Systems2014Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    With the growing complexity of embedded real-time systems, requirements validation becomes an ever-more critical activity for developing such systems. Studies have revealed that most of the anomalies, discovered in the development of complex systems, belong to requirement and specification phases. To ease the situation, many efforts have been investigated into the area. Model-based techniques, enabling formal semantics and requirements traceability, are emerging as promising solutions to cost-effective requirements validation. In these techniques, the functional behaviors derived from lower-level requirements are specified in terms of analyzable models at a certain level of abstraction. Further, upper-level requirements are formalized into verifiable queries and/or formulas. Meanwhile, trace links between requirements at various levels of abstraction as well as between requirements and subsequent artifacts (such as verifiable queries and/or formulas, and analyzable models) are built, through which the queries and/or formulas can be fed into the corresponding models. However, such model-based techniques suffer from some limitations, such as how to support semi- or fully-automatic trace links creation between diverse development artifacts, how to ease the demand of heavy mathematics background knowledge to specify queries and/or formulas, and how to analyze models without encountering the state explosion problem. 

     

    In this thesis, we cover two aspects centering around requirements validation to ease the aforementioned limitations, which are mainly about requirements traceability and model-based requirements validation. In particular, the technical contributions are four-fold: 1) we have introduced an improved VSM-based requirements traceability creation/recovery approach using a novel context analysis and, 2) we have proposed a lightweight model-based approach to requirements validation by using the Timed Abstract State Machine (TASM) language with newly defined Observer and Event constructs and, 3) we have combined our model-based approach with a restricted use case modeling approach for feature-oriented requirements validation and, 4) we have improved the Observer construct of TASM via proposing a new observer specification logic to facilitate the observer specification, as well as defining the corresponding observer execution process. Finally, we have demonstrated the applicability of our contributions in real world usage through various applications.

  • 1814.
    Zhou, Jiale
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    An Ontological Approach to Safety Analysis of Safety-Critical Systems2017Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Safety-critical systems (SCSs) have become an intrinsic part of human dailylife in multiple domains, such as automotive, avionics, and rail industries. Such systems are not only required to implement the functionality they should provide, but also have to satisfy a set of safety requirements in order to ensure the mitigation of hazardous consequences.

    It is fundamental that safety requirements are defined based on the results issued from safety analysis. Various studies have asserted that most significant flaws in the safety requirements are related to the omission of hazards and causes associated with the identified hazards in early stages of SCSs development. The main drawbacks of the current practice applied in safety analysis,lie in that:

    due to the lack of a common understanding of the hazard concept, the hazards and their causes are typically identified in accordance to the intuition and experience of the analysts and,

    analysts are inclined to identify generic causes for a certain hazard description, for example, “Design flaw, Coding error, and Human error”and,

    there is an essential need to formalize the experience of the analysts in a structured way, in order to save effort and,

    since traditional safety analysis techniques are usually based on well known system behaviors represented by models, such as automata and sequence diagrams, a new approach is needed when such behavioral models are not available.

    These considerations motivate us to formulate the following general research question: How can safety analysis, within the context of safety-critical systems, be conducted to reduce the omission of potential hazards and their causes in early stages of the system development life-cycle?

    In this thesis, we propose an ontological approach to safety analysis for safety-critical systems, which mainly consists of four pieces of work:

    we propose an ontological interpretation of the hazard concept, calledthe Hazard Ontology (HO), to define an explicit representation of theknowledge of hazards and their relations with the system under analysisand existing environment and,

    we propose an approach to identify hazards in early stages of thesafety-critical systems development, based on the HO and,

    we propose an approach to identify the causes associated with a certain hazard description for safety-critical systems, based on the HO and,

    we propose a heuristic approach to safety requirements elicitation,based on the HO.

  • 1815.
    Zhou, Jiale
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Requirements development and management of embedded real-time systems2014Ingår i: 2014 IEEE 22nd International Requirements Engineering Conference, RE 2014 - Proceedings, 2014, s. 479-484Konferensbidrag (Refereegranskat)
    Abstract [en]

    It is well recognized that most of the anomalies, discovered in the development of embedded real-time systems, belong to requirement and specification phases. To ease the situation, many efforts have been investigated into the area. For requirements development, especially requirements validation and verification, model-driven architecture techniques can be considered as a cost-efficient solution. In order to utilize such advantages, the design of the proposed system is often specified in terms of analyzable models at the certain level of abstraction. Further, different levels of requirements are translated into verifiable queries and fed into the models to be either validated or verified. For requirements management, requirements traceability provides critical support for performing change impact analysis, risk analysis, regression testing, etc. In this thesis, we cover several topics about requirements validation, requirements verification, and requirements traceability. In particular, the technical contributions are three-fold: 1) we propose an approach to requirements validation by using the extended Timed Abstract State Machine (TASM) language with newly defined TASM constructs and, 2) we present a simulation-based method which is powered up by statistical techniques to conduct requirements verification, working with industrial applications and, 3) we introduce an improved VSM-based requirements traceability recovery approach using a novel context analysis. Further, we have demonstrated the applicability of our contributions in real world usage through various case studies.

  • 1816.
    Zhou, Jiale
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Hänninen, Kaj
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lu, Yue
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lundqvist, Kristina
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Provenzano, Luciana
    A Hazard Domain Ontology for Preliminary Hazard Analysis in Reuse Scenarios2016Rapport (Övrigt vetenskapligt)
  • 1817.
    Zhou, Jiale
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Hänninen, Kaj
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lundqvist, Kristina
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    A Hazard Modeling Language for Safety-Critical Systems Based on the Hazard Ontology2017Ingår i: 43rd Euromicro Conference on Software Engineering and Advanced Applications SEAA'17, 2017, s. 301-304Konferensbidrag (Refereegranskat)
    Abstract [en]

    Preliminary hazard analysis (PHA) is a key safety-concerned activity, applied during the early stages of safety-critical systems development process, aiming to provide stakeholders with a general understanding of potential hazards. The identified hazards will be described and serve as a basis to further identify mitigation mechanisms in the subsequent development process. However, since various stakeholders will be involved in the identification process, a common understanding of the nature of hazards among stakeholders, such as what a hazard consists of and how to describe it without ambiguities, is of crucial importance to achieve the goal of PHA. In this work, we propose a hazard modeling language (HML) based on a hazard domain ontology, i.e., the Hazard Ontology, in order to facilitate the specification of identified hazards. In addition, we present an approach to the transformation from natural language hazard descriptions into the HML specification. Finally, an industrial PHA example is used to illustrate the usefulness of our work.

  • 1818.
    Zhou, Jiale
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Hänninen, Kaj
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lundqvist, Kristina
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lu, Yue
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Provenzano, Luciana
    Bombardier Transportation AB, Sweden.
    Forsberg, Kristina
    Saab AB, Sweden.
    An Environment-Driven Ontological Approach to Requirements Elicitation for Safety-Critical Systems2015Ingår i: 23rd IEEE International Requirements Engineering Conference RE'15, 2015, s. 247-251Konferensbidrag (Refereegranskat)
    Abstract [en]

    The environment, where a safety critical system (SCS) operates, is an important source from which safety requirements of the SCS can originate. By treating the system under construction as a black box, the environment is typically documented as a number of assumptions, based on which a set of environmental safety requirements will be elicited. However, it is not a trivial task in practice to capture the environmental assumptions to elicit safety requirements. The lack of certain assumptions or too strict assumptions will either result in incomplete environmental safety requirements or waste many efforts on eliciting incorrect requirements. Moreover, the variety of operating environment for an SCS will further complicate the task, since the captured assumptions are at risk of invalidity, and consequently the elicited requirements need to be revisited to ensure safety has not been compromised by the change. This short paper presents an on-going work aiming to 1) systematically organize the knowledge of system operating environment and, 2) facilitate the elicitation of environmental safety requirements. We propose an ontological approach to achieve the objectives. In particular, we utilize conceptual ontologies to organize the environment knowledge in terms of relevant environment concepts, relations among them and axioms. Environmental assumptions are captured by instantiating the environment ontology. An ontological reasoning mechanism is also provided to support elicitation of safety requirements from the captured assumptions.

  • 1819.
    Zhou, Jiale
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Hänninen, Kaj
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lundqvist, Kristina
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Provenzano, Luciana
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    An Ontological Approach to Identify the Causes of Hazards for Safety-Critical Systems2017Ingår i: 2017 2nd International Conference on System Reliability and Safety ICSRS'17, 2017, s. 405-413Konferensbidrag (Refereegranskat)
    Abstract [en]

    Preliminary hazard analysis (PHA) is a key safety-concerned technique, applied in early stages of safety critical systems development, aiming to provide stakeholders with a general understanding of potential hazards together with their causes. Various studies have asserted that most significant flaws in hazard analysis techniques are related to the omission of causes associated with the identified hazards. In addition, identified causes are sometimes described in too generic terms to provide useful guidance for subsequent activities. In this paper, we propose an approach to explore and identify the causes associated with the hazards from a PHA, aiming to improve the results of hazard causes identification in terms of completeness and usefulness. To achieve the goal, the proposed approach utilizes the hazard-related concepts and relations defined in a hazard domain ontology presented in our previous work. Furthermore, an application scenario of a train control system is used to evaluate our approach.

  • 1820.
    Zhou, Jiale
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Hänninen, Kaj
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lundqvist, Kristina
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Provenzano, Luciana
    Bombardier Transportation, Sweden.
    An Ontological Interpretation of the Hazard Concept for Safety-Critical Systems2017Ingår i: PROCEEDINGS OF THE 27TH EUROPEAN SAFETY AND RELIABILITY CONFERENCE (ESREL 2017), PORTOROZ , SLOVENIA, 18–22 JUNE 2017, 2017, s. 183-185Konferensbidrag (Refereegranskat)
    Abstract [en]

    The hazard concept has been extensively used in the literature and defined in an informal way, which serves as a guidance on identifying the potential hazards during the development of safety-critical systems. Intuitively, the definitions seem to be consistent and easy to understand. However, when we take a closer look at these definitions, ambiguities may arise, and real-world semantics need to be defined. In this work, we propose a hazard domain ontology, i.e., the Hazard Ontology (HO), to provide an ontological interpretation of hazard. To tackle the aforementioned issues, the HO is grounded in the Unified Foundational Ontology (UFO) to utilize the benefits provided by taking foundational concepts into account. Finally, we show some useful findings when we use the proposed ontology to analyze the hazard descriptions from an industrial passenger train project.

  • 1821.
    Zhou, Jiale
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lundqvist, Kristina
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    The Observer-based Technique for Requirements Validation in Embedded Real-time Systems2014Ingår i: Proceedings of 1st International Workshop on Requirements Engineering and Testing (RET), 2014, s. 47-54Konferensbidrag (Refereegranskat)
    Abstract [en]

    Model-based requirements validation is an increasingly attractive approach to discovering hidden flaws in requirements in the early phases of systems development life cycle. The application of using traditional methods such as model checking for the validation purpose is limited by the growing complexity of embedded real-time systems (ERTS). The observer-based technique is a lightweight validation technique, which has shown its potential as a means of validating the correctness of model behaviors. In this paper, the novelty of our contributions is three-fold: 1) we formally define the observer constructs for our formal specification language namely the Timed Abstract State Machine (TASM) language and, 2) we propose the Events Monitoring Logic (EvML) to facilitate the observer specification and, 3) we show how to execute observers to validate the requirements describing the functional behaviors and non-functional properties (such as timing) of ERTS. We also illustrate the applicability of the extended TASM language through an industrial application of a Vehicle Locking-Unlocking system.

  • 1822.
    Zhou, Y.
    et al.
    East China University of Science and Technology.
    Li, S.
    East China University of Science and Technology.
    Xiong, Ning
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Improved Vine Copula-Based Dependence Description for Multivariate Process Monitoring Based on Ensemble Learning2019Ingår i: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 58, nr 9, s. 3782-3796Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper proposes a boosting vine copula-based dependence description (BVCDD) method for multivariate and multimode process monitoring. The BVCDD aims to improve the standard vine copula-based dependence description (VCDD) method by establishing an ensemble of submodels from sample directions based on a boosting strategy. The generalized Bayesian inference-based probability (GBIP) index is introduced to assess the degrees of a VCDD model (submodel) to depict different samples, which means how likely an observation is under the probabilistic model for the system. Every sample is weighted individually according to the depiction degree. The weights are then used to choose a certain number of samples for each succeeding submodel. In this way, the samples with large error in the preceding model can be selected for training the next submodel. Moreover, the number of submodels as well as the number of training samples chosen for every submodel are determined adaptively in the ensemble learning process. The proposed BVCDD method can not only solve weak sample problems but also remove redundant information in samples. To examine the performance, empirical evaluations have been conducted to compare the BVCDD method with some other state-of-the-art methods in a numerical example, the Tennessee Eastman (TE) process, and an acetic acid dehydration process. The results show that the developed BVCDD models are superior to those obtained by the counterparts on weak samples in both accuracy and stability. 

  • 1823.
    Zhu, Kaiqian
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Limited Preemptive Earliest Deadline First Scheduling of Real-Time Tasks on Multiprocessors2015Självständigt arbete på avancerad nivå (magisterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Real-time systems are employed in many areas, such as aerospace and defenses. In real-time systems, especially in hard real-time systems, it is important to meet the associated time requirements. With the increasing demand for high speed processing capabilities, the requirement for high computing power is becoming more and more urgent. However, it is no longer possible to increase processor speeds because of thermal and power constraints. Consequently, industry has focused on providing more computing capabilities using more number of processors.As to the scheduling policies, they can be classified into two categories, preemptive and non-preemptive. Preemptive scheduling allows preemptions arbitrarily, whereas it implies prohibitively high preemption related overheads. On the contrary, the non-preemptive scheduling which do not allow preemption at all, will not have such overheads, but suffers due to the block time on high priority tasks. Limited preemptive scheduling, that builds on the best of preemptive and non-preemptive scheduling, benefits from the limited number of preemptions without a major effect on real-time properties. It is proved that limited preemptive scheduling dominates preemptive and non-preemptive scheduling on uniprocessors under fixed priority. However, less work has been done on multiprocessor limited preemptive scheduling, especially under Earliest Deadline First (EDF). On a multiprocessor, limited preemptively scheduling real-time tasks imply an additional challenge with respect to determining which of the running task to preempt. On one extreme, the scheduler can preempt the lowest priority running task and this is referred to as Adaptive Deferred Scheduling (ADS). On the other hand, the scheduler can preempt any lower priority running task that becomes pre-emptible. Such a scheduler is referred to as Regular Deferred Scheduling (RDS)In this work, we empirically investigate the performance of ADS and RDS, and compare it with the global preemptive and non-preemptive scheduling, in the context of an EDF based scheduler. Our empirical investigation revealed that the number of preemptions under ADS is less compared to RDS, at runtime. This is due to the fact that by delaying preemptions, the higher priority tasks that are released subsequently will run in priority order thereby avoiding the need for more preemptions. Also, by delaying preemptions, the possibility of one or more processors becoming available increases. Experiments investigating the schedulability ratio shows that ADS and RDS performs almost equally well, but better than fully non-preemptive scheduling.

  • 1824.
    Zimmerman, Marc
    et al.
    Massachusetts Institute of Technology, Cambridge, USA.
    Lundqvist, Kristina
    Massachusetts Institute of Technology, Cambridge, USA.
    Leveson, Nancy
    Massachusetts Institute of Technology, Cambridge, USA.
    Investigating the readability of state-based formal requirements specification languages2002Ingår i: Proc. 24th International Conference on Software Engineering ICSE02, 2002, s. 33-43, artikel-id 7Konferensbidrag (Övrigt vetenskapligt)
  • 1825.
    Åberg, Christian
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Automated Deployment of Customer-Premises Equipment2016Självständigt arbete på grundnivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Zero touch deployment tools perform installation and configuration of computer networking devices without human interaction. Modern zero touch deployment tools generally lack support for routers and are platform dependent. This forces Internet Service Providers to rely on manual node deployment methods when deploying Customer-Premise Equipment which is time consuming and error prone. This thesis investigates how the process of deploying Customer-Premises Equipment can be automated and optimized. State-of-the-art is discussed to point out requirements and possible improvements. Based on that, a tool is implemented performing deployment of Customer-Premises Equipment while minimizing manual intervention. As Internet Service Providers typically work with equipment from various vendors, multivendor support is implemented. This thesis studies common methods for initial Customer-Premises Equipment configuration. Request for Comments and Technical manuals are consulted regarding network protocols, zero touch deployment tools and router operating systems.

  • 1826.
    Åberg, Denny
    et al.
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Gunnarsson, Tommy
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Norin, Peder
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Steps to Microwave Probing of Complex Dielectric Bodies2005Ingår i: Midwest Symposium on Circuits and Systems, Volume 2005, 2005, s. 1932-1935Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Microwave probing of dielectric materials is a challenging application of microwaves. This study investigates a Finite Difference Time Domain electro-magnetic wave simulation tool with the intent of establishing a quantitative simulation environment for microwave probing techniques. Measurements were compared to simulations on distilled water and a phantom resembling a human breast with and without a 10 mm diameter tumor. The measurements showed high signal differences on tumor insertion as well as on variation of the tumor position within the phantom. The simulation results shows agreement on quantitative levels for the whole phantom object, however the simulation results on tumor variation could not be quantitatively correlated to measurements

  • 1827.
    Åkerberg, Anna
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Folke, Mia
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Pedometer cell phone applications and future trends in measuring physical activity2013Ingår i: Information Systems and Technologies for Enhancing Health and Social Care, IGI Global , 2013, s. 324-339Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    A huge proportion of the world population is suffering from lifestyle related and preventable welfare diseases. Physical activity is one important means of achieving beneficial health impacts and of reducing the risk of chronic disease. Pedometers are often used to measure physical activity. Nowadays, cell phones are very common, and pedometer applications enable measurements to be made by a device that is already owned. This chapter presents a study of the measurement accuracy of pedometer cell phone applications. The results show that only one combination of pedometer application and cell phone provided high accuracy when tested by different test persons. In some cases, the measurements indicate that the orientation of the cell phone used during measurement might be relevant. In addition, it would be valuable to gain knowledge about the overall and everyday physical activity pattern, which would be very valuable in contributing to a healthier population.

  • 1828.
    Åkerberg, Anna
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Söderlund, Anne
    Mälardalens högskola, Akademin för hälsa, vård och välfärd, Hälsa och välfärd.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Investigation of the validity and reliability of a smartphone pedometer application2016Ingår i: European Journal of Physiotherapy, ISSN 2167-9169, E-ISSN 2167-9177, Vol. 18, nr 3, s. 185-193Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to investigate the validity and measurement agreement of a smartphone pedometer application and a traditional pedometer, both compared to manual step count, in six environments. The study also examined the relative reliability of two positions of the smartphone pedometer application in the six environments. Twenty participants carried two smartphones (iPhone 4S) with the same pedometer application (Pedometer FREE GPSþ) in two device positions together with a traditional pedometer (Yamax LS2000) while walking in six environments. The pedometer application in the chest position (app chest) differed significantly from the manual step count when walking uphill (p¼0.003), the application in the trouser (pants) position (app pants) differed for downhill (p¼0.001) and the traditional pedometer (trad ped) differed upstairs (p¼0.007). The measurement agreement was high for app pants uphill, app chest downhill and trad ped downstairs. The relative reliability was fair for app chest, but poor for app pants. In conclusion, the pedometer application and traditional pedometer were valid for step self-monitoring in some environments, and the measurement agreement compared to manual step count was mainly medium to high. The relative reliability for the smartphone pedometer application was partly acceptable. Smartphones could be useful in some environments for physical activity self-monitoring.

  • 1829.
    Åkerberg, Anna
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Söderlund, Anne
    Mälardalens högskola, Akademin för hälsa, vård och välfärd, Hälsa och välfärd.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Technologies for physical activity self-monitoring: a study of differences between users and non-users2017Ingår i: Open Access Journal of Sports Medicine, ISSN 1179-1543, E-ISSN 1179-1543, Vol. 8, s. 17-26Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Different kinds of physical activity (PA) self-monitoring technologies are used today to monitor and motivate PA behavior change. The user focus is essential in the development process of this technology, including potential future users such as representatives from the group of non-users. There is also a need to study whether there are differences between the groups of users and non-users. The aims of this study were to investigate possible differences between users and non-users regarding their opinions about PA self-monitoring technologies and to investigate differences in demographic variables between the groups. Materials and methods: Participants were randomly selected from seven municipalities in central Sweden. In total, 107 adults responded to the Physical Activity Products Questionnaire, which consisted of 22 questions. Results: Significant differences between the users and non-users were shown for six of the 20 measurement-related items: measures accurately (p = 0.007), measures with high precision (p = 0.024), measures distance (p = 0.020), measures speed (p = 0.003), shows minutes of activity (p = 0.004), and shows geographical position (p = 0.000). Significant differences between the users and non-users were also found for two of the 29 encouragement items: measures accurately (p = 0.001) and has long-term memory (p = 0.019). Significant differences between the groups were also shown for level of education (p = 0.030) and level of physical exercise (p = 0.037). Conclusion: With a few exceptions, the users and the non-users in this study had similar opinions about PA self-monitoring technologies. Because this study showed significant differences regarding level of education and level of physical exercise, these demographic variables seemed more relevant to investigate than differences in opinions about the PA self-monitoring technologies.

  • 1830.
    Åkerberg, Anna
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Söderlund, Anne
    Mälardalens högskola, Akademin för hälsa, vård och välfärd, Hälsa och välfärd.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Utvärdering av en stegräknarapplikation; mätnoggrannhet i olika mätmiljöer och positioner2014Ingår i: Medicinteknikdagarna 2014 MTD10, 2014Konferensbidrag (Refereegranskat)
  • 1831.
    Åkerberg, Johan
    et al.
    ABB AB, Corporate Research, Sweden.
    Björkman, Mats
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Exploring Network Security in PROFIsafe2009Ingår i: Lecture Notes In Computer Science: Proceedings of the 28th International Conference on Computer Safety, Reliability, and Security, Heidelberg: Springer-Verlag , 2009, s. 67-80Konferensbidrag (Refereegranskat)
    Abstract [en]

    Safety critical systems are used to reduce the probability of failure that could cause danger to person, equipment or environment. The increasing level of vertical and horizontal integration increases the security risks in automation. Since the risk of security attacks can not be treated as negligible anymore, there is a need to investigate possible security attacks on safety critical communication.

    In this paper we show that it is possible to attack PROFIsafe and change the safety-related process data without any of the safety measures in the protocol detecting the attack. As a countermeasure to network security attacks, the concept of security modules in combination with PROFIsafe will reduce the risk of security attacks, and is in line with the security concept defense-in-depth.

  • 1832.
    Åkerberg, Johan
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Gidlund, Mikael
    Lennvall, Tomas
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Landernäs, Krister
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Björkman, Mats
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Design Challenges and Objectives in Industrial Wireless Sensor Networks2013Ingår i: Industrial Wireless Sensor Networks: Applications, Protocols, and Standards / [ed] V. Çağrı Güngör, CRC Press, 2013Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 1833.
    Åkerblom, Jacob
    Mälardalens högskola, Akademin för innovation, design och teknik.
    UTVÄRDERING AV UTVALDA SD-WAN PRODUKTER2016Självständigt arbete på grundnivå (högskoleexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Denna jämförelsestudie ämnar att undersöka marknadens leverantörer av nätverksutrustning de- finierade som Software Defined Wide Area Networks(SD-WAN). SD-WAN är en innovativ teknik som applicerar virtualisering och Software defined networking koncept i Wide Area Networks (WAN) för att skapa kostnadseffektiva nätverk. Studien har utförts på företaget Curitiba som idag arbetar med konsulttjänster inom utvalda WAN-optimering och SD-WAN-produkter. Arbetets syfte är att utvärdera SD-WAN-lösningar och specificera i vilken typ av företagsnätverk lösningen bäst appliceras. Undersökningen börjar med en utredning av dagens organisationsnätverk för att kunna utföra en jämförelse mot SD-WAN. Därefter utvärderas fem leverantörer av nätverksutrustning definierade som SD-WAN, dessa är: Cisco IWAN, CloudGenix, Riverbed Steelconnect, Talari och Viptela. Produkter från Viptela utvärderas i ett test som undersöker komplexiteten i konfiguration av produkten. Utöver SD-WAN jämförelsen undersöks dagens state of practice och vilka fördelar samt nackdelar denna har över SD-WAN. Cisco IWAN är en sammanslagning av Ciscos tidigare funktioner som tillammans bildar en komplett SD-WAN-lösning, för att uppnå detta behöver produkterna kompletteras med programvarulicenser. CloudGenix är en nystartad nätverksleverantör som erbjuder en SD-WAN-produkt som liknar många andra aktörer men utmärker sig med avancerad applikationsidentifikation. Riverbed SteelConnect är intressant för organisationer som söker en simplifierad helhetslösning med ett centraliserat gränssnitt. Talari var en av de första SDWAN-leverantörerna och fokuserar på applikationsprestanda och pålitlighet men saknar några av funktionerna som de andra aktörerna erbjuder. Viptela erbjuder en simplifierad SD-WAN-lösning med hög skalbarhet. SD-WAN som teknik har många spännande funktioner, organisationer som planerar att investera i en uppgradering av WAN-infrastruktur bör undersöka SD-WAN alternativ.

  • 1834.
    Åkerholm, Mikael
    et al.
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Carlson, Jan
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Fredriksson, Johan
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Hansson, Hans
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Håkansson, John
    Uppsala University, Sweden.
    Möller, Anders
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Pettersson, Paul
    Uppsala University, Sweden.
    Tivoli, Massimo
    University of L'Aquila, Italy.
    The SAVE approach to component-based development of vehicular systems2007Ingår i: Journal of Systems and Software, ISSN 0164-1212, E-ISSN 1873-1228, Vol. 80, nr 5, s. 655-667Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The component-based strategy aims at managing complexity, shortening time-to-market, and reducing maintenance requirements by building systems with existing components. The full potential of this strategy has not yet been demonstrated for embedded software, mainly because of specific requirements in the domain, e.g., those related to timing, dependability, and resource consumption. We present SaveCCT - a component technology intended for vehicular systems, show the applicability of SaveCCT in the engineering process, and demonstrate its suitability for vehicular systems in an industrial case-study. Our experiments indicate that SaveCCT provides appropriate expressiveness, resource efficiency, analysis and verification support for component-based development of vehicular software. 

  • 1835.
    Åkerholm, Mikael
    et al.
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Carlson, Jan
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Håkansson, John
    Uppsala University, Uppsala, Sweden.
    Hansson, Hans
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Sjödin, Mikael
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Nolte, Thomas
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Pettersson, Paul
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    The SaveCCM Language Reference Manual2007Rapport (Övrigt vetenskapligt)
    Abstract [en]

    This language reference describes the syntax and semantics of SaveCCM, a

    component modeling language for embedded systems designed with vehicle applications and safety concerns in focus. The SaveCCM component model was

    defined within the SAVE project. The SAVE components are influenced mainly

    by the Rubus component technology, with a switch concept similar to that

    in Koala. The semantics is defined by a transformation into timed automata

    with tasks, a formalism that explicitly models timing and real-time task scheduling.

    The purpose of this document is to describe a semantics of the SAVE component modeling language, which can be used to describe timing and functional behavior of components. The model of a system is in some cases an over approximation of the actual system behavior. An implementation of a model can resolve non-determinism e.g. by merging tasks or assigning a scheduling policy (such as static scheduling or fixed priority, preemptive or not) that will resolve

    the non-determinism.

  • 1836.
    Åkerholm, Mikael
    et al.
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Möller, Anders
    Hansson, Hans
    Nolin, Mikael
    Towards a Dependable Component Technology for Embedded System ApplicationsManuskript (Övrigt vetenskapligt)
  • 1837.
    Åsberg, Mikael
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Behnam, Moris
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Nolte, Thomas
    Mälardalens högskola, Akademin för innovation, design och teknik.
    An Experimental Evaluation of Synchronization Protocol Mechanisms in the Domain of Hierarchical Fixed-Priority Scheduling2013Ingår i: ACM International Conference Proceeding Series, 2013, 2013, s. 77-85Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents an extensive implementation study where we evaluate and compare different synchronization protocol mechanisms within the domain of two-level hierarchical fixed-priority preemptive scheduling. These protocol mechanisms include HSRPnP (Hierarchical Stack Resource Policy no Payback), HSRPwP (Hierarchical Stack Resource Policy with Payback), SIRAP (Subsystem Integration and Resource Allocation Policy), RRP (Rollback Resource Policy) and SRPwD (Stack Resource Policy with Donation). In an attempt to shed new light to the research in this area, we focus on the actual software implementation of these protocols in a widely used real-time operating system (VxWorks). This study is not based on worst-case schedulability analysis which is the most common angle of work in this research field. All five protocols have been implemented, tested and executed for several months with many different parameters, for example; variant number of subsystems, number of resources, system utilization settings, resource allocation strategies etc. These tests generated a large amount of useful data, for example, protocol overhead, effective subsystem utilization, number of protocol mechanism invocations etc. Due to the large complexity and size of this data, we analyzed the data with state-of-the-art statistical methods and tools (Principal Component Analysis) in order to grasp the efficiency of the protocols with respect to a large number of different parameters.

  • 1838.
    Åsberg, Mikael
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Nolte, Thomas
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Kato, Shinpei
    Carnegie Mellon University, Department of Electrical and Computer Engineering, United States.
    A Loadable Task Execution Recorder for Hierarchical Scheduling in Linux2011Ingår i: Proceedings - 17th IEEE International Conference on Embedded and Real-Time Computing Systems and Applications, RTCSA 2011, 2011, s. 380-387Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents a Hierarchical Scheduling Framework (HSF) recorder for Linux-based operating systems. The HSF-recorder is a loadable kernel module that is capable of recording tasks and servers without requiring any kernel modifications. Hence, it complies with the reliability and stability requirements in the area of embedded systems where proven versions of Linux are preferred. The recorder is built upon the loadable real-time scheduler framework RESCH (REal-time SCHed- uler). We evaluate our recorder by comparing the overhead of this solu- tion against two other recorders. Also, the tracing accuracy of the HSF- recorder is tested by running a media-processing task together with periodic real-time Linux tasks in combination with servers. We experiment with different task parameters and scheduling strategies and measure the performance of the media-processing task. The tests are recorded with the HSF-recorder, and the Ftrace recorder, in order to show the correctness of the experiments and the HSF-recorder itself.

  • 1839.
    Åsberg, Mikael
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Pettersson, Paul
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Nolte, Thomas
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Evaluating the Run-Time Performance of Synthesised Resource-Reservation Schedulers Using TAtoC, UPPAAL and Frama-C2013Rapport (Övrigt vetenskapligt)
  • 1840.
    Åsberg, Mikael
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Pettersson, Paul
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Nolte, Thomas
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Modelling, Verification and Synthesis of Two-Tier Hierarchical Fixed-Priority Preemptive Scheduling2011Ingår i: Proceedings - 23rd EUROMICRO Conference on Real-Time Systems (ECRTS'11), 2011, s. 172-181Konferensbidrag (Refereegranskat)
    Abstract [en]

    Hierarchical scheduling has major benefits when it comes to integrating hard real-time applications. One of those benefits is that it gives a clear runtime separation of applications in the time domain. This in turn gives a protection against timing error propagation in between applications. However, these benefits rely on the assumption that the scheduler itself schedules applications correctly according to the scheduling parameters and the chosen scheduling policy. A faulty scheduler can affect all applications in a negative way. Hence, being able to guarantee that the scheduler is correct is of great importance. Therefore, in this paper, we study how properties of hierarchical scheduling can be verified. We model a hierarchically scheduled system using task automata, and we conduct verification with model checking using the Times tool. Further, we generate C-code from the model and we execute the hierarchical scheduler in the Vx Works kernel. The CPU and memory overhead of the modelled scheduler is compared against an equivalent manually coded two-level hierarchical scheduler. We show that the worst-case memory consumption is similar and that there is a considerable difference in CPU overhead.

  • 1841.
    Åstrand, Elaine
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    A continuous time-resolved measure decoded from EEG oscillatory activity predicts working memory task performance2018Ingår i: Journal of Neural Engineering, ISSN 1741-2560, E-ISSN 1741-2552, Vol. 15, nr 3, artikel-id 036021Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objective. Working memory (WM), crucial for successful behavioral performance in most of our everyday activities, holds a central role in goal-directed behavior. As task demands increase, inducing higher WM load, maintaining successful behavioral performance requires the brain to work at the higher end of its capacity. Because it is depending on both external and internal factors, individual WM load likely varies in a continuous fashion. The feasibility to extract such a continuous measure in time that correlates to behavioral performance during a working memory task remains unsolved. Approach. Multivariate pattern decoding was used to test whether a decoder constructed from two discrete levels of WM load can generalize to produce a continuous measure that predicts task performance. Specifically, a linear regression with L2-regularization was chosen with input features from EEG oscillatory activity recorded from healthy participants while performing the n-back task, n is an element of [1, 2]. Main results. The feasibility to extract a continuous time-resolved measure that correlates positively to trial-bytrial working memory task performance is demonstrated (r = 0.47, p < 0.05). It is furthermore shown that this measure allows to predict task performance before action (r = 0.49, p < 0.05). We show that the extracted continuous measure enables to study the temporal dynamics of the complex activation pattern of WM encoding during the n-back task. Specifically, temporally precise contributions of different spectral features are observed which extends previous findings of traditional univariate approaches. Significance. These results constitute an important contribution towards a wide range of applications in the field of cognitive brain-machine interfaces. Monitoring mental processes related to attention and WM load to reduce the risk of committing errors in high-risk environments could potentially prevent many devastating consequences or using the continuous measure as neurofeedback opens up new possibilities to develop novel rehabilitation techniques for individuals with degraded WM capacity.

  • 1842.
    Åstrand, Elaine
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. Université Claude Bernard, Lyon, France.
    Wardak, Claire
    Université Claude Bernard, Lyon, France.
    Baraduc, Pierre
    Université Claude Bernard, Lyon, France.
    Ben Hamed, Suliann
    Université Claude Bernard, Lyon, France.
    Direct Two-Dimensional Access to the Spatial Location of Covert Attention in Macaque Prefrontal Cortex.2016Ingår i: Current Biology, ISSN 0960-9822, E-ISSN 1879-0445, Vol. 26, nr 13, s. 1699-1704Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Direct access to motor cortical information now enables tetraplegic patients to precisely control neuroprostheses and recover some autonomy. Incontrast, explicit access to higher cortical cognitive functions, such as covert attention, has been missing. Indeed, this cognitive information, known only to the subject, can solely be inferred by an observer from the subject's overt behavior. Here, we present direct two-dimensional real-time access to where monkeys are covertly paying attention, using machine-learning decoding methods applied to their ongoing prefrontal cortical activity. Decoded attention was highly predictive of overt behavior in a cued target-detection task. Indeed, monkeys had a higher probability of detecting a visual stimulus as the distance between decoded attention and stimulus location decreased. This was true whether the visual stimulus was presented at the cued target location or at another distractor location. In error trials, in which the animals failed to detect the cued target stimulus, both the locations of attention and visual cue were misencoded. This misencoding coincided with a specific state of the prefrontal cortical population in which the shared variability between its different neurons (or noise correlations) was high, even before trial onset. This observation strongly suggests a functional link between high noise-correlation states and attentional failure. Overall, this real-time access to the attentional spotlight, as well as the identification of a neural signature of attentional lapses, open new perspectives both to the study of the neural bases of attention and to the remediation or enhancement of the attentional function using neurofeedback.

  • 1843.
    Çollaku, Vasja
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Shestani, Paolo
    Mälardalens högskola, Akademin för innovation, design och teknik.
    A Formal Analysis Framework For EAST-ADL Architectural Models Extended With Behavioral Specifications In Simulink2019Självständigt arbete på avancerad nivå (magisterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Model-Driven Development is a development approach which is being used frequently in the automotive context in order to design models. EAST-ADL is an architectural language which models systems according to their architectural features, whereas Simulink is a tool environment which models systems according to their behavior. In this thesis work, we propose a set of transformation rules that take into consideration the EAST-ADL architectural model details and the behavioral specifications in Simulink, and generate a formal model, which can be verified UPPAAL model checker. Moreover, we implement these proposed transformation rules in a tool that automates them. The transformation rules proposed in this thesis work would be implemented for every EAST-ADL file with Simulink behavior specifications, generated by the MetaEdit+ tool. Properties like timing constraints, triggering and hierarchy in both EAST-ADL and Simulink have been considered by the transformation rules. Finally, the Brake-by-Wire case study is used to validate the tool and assess the mapping of the elements.

  • 1844.
    Çürüklü, Baran
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Lansner, Anders
    Configuration-specific facilitation phenomena explained by layer 2/3 summation pools in V12009Konferensbidrag (Refereegranskat)
  • 1845. Ödman, Torbjörn
    et al.
    Ankarson, Peter
    SP Technical Research Institute of Sweden, Borås, Sweden.
    Hallbjörner, Paul
    SP Technical Research Institute of Sweden, Borås, Sweden.
    Experimental study of path loss for UHF band communication near water surface2012Ingår i: International Journal on Communications Antenna and Propagation, ISSN 2039-5086, Vol. 2, nr 3, s. 215-219Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The UHF band is often used for communication over water. Presented work quantifies path loss for this scenario. Experimental results are presented within 200 MHz to 1000 MHz, with the antennas positioned up to 2 m above the water surface. Path loss models are created from the measured data.

  • 1846. Ödman, Torbjörn
    et al.
    Hallbjörner, Paul
    SP Technical Research Institute of Sweden, Borås, Sweden.
    Vivaldi antenna with low frequency resonance for reduced dimensions2013Ingår i: 2013 7th European Conference on Antennas and Propagation, EuCAP 2013, 2013, s. 2457-2459Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper describes a broadband antenna with a design similar to a Vivaldi antenna. The difference is that a resonance is added to get a widerfrequency range, which is used to reduce the dimensions of the antenna. The antenna is built and characterized by S11, radiation patterns, and gain.

  • 1847.
    Ödman, Torbjörn
    et al.
    Saab Electronic Defence Systems, Göteborg, Sweden.
    Welinder, J.
    SP Technical Research Institute of Sweden, Borås, Sweden.
    Andersson, N.
    Södra Älvsborgs Hospital, Borås, Sweden .
    Otterskog, Magnus
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Ödman, N.
    Larsson, C.
    Lund University, Lund, Sweden.
    A study of different fabrics to increase radar cross section of humans2015Ingår i: Studies in Health Technology and Informatics, vol. 211, 2015, s. 201-206Konferensbidrag (Refereegranskat)
    Abstract [en]

    This purpose of the study was to increase the visibility on radar for unprotected pedestrians with the aid of conducting fabric. The experiment comprised measurements of four types of fabric to determine the radio frequency properties, such as radar cross section (RCS) for the vehicle radar frequency 77 GHz and transmission (shielding) in the frequency range 3-18 GHz. Two different thicknesses of polypyrrole (PPy) nonvowen fabric were tested and one thickness for 30 % and 40 % stainless steel fabrics respectively. A jacket with the thinner nonvowen material and one with 40 % steel were tested and compared to an unmodified jacket in the RCS measurement. The measurement showed an increase in RCS of 4 dB for the jacket with the 40 % steel lining compared to the unmodified jacket. The transmission measurement was aimed at determining the fabric with the highest transmission of an incoming radio wave. The 30 % steel fabric and the two thicknesses of the nonvowen fabrics were tested. One practical application is for example the use of radar reflective material in search and rescue (SAR) clothes. The study showed that the 30 % steel fabric was the best candidate for further RCS measurements.

  • 1848.
    Ödman, Torbjörn
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Ödman, Natalia
    Södra Älvsborgs sjukhus, Borås, Sweden.
    Rabotchi, Eugeni
    Ericsson AB, Borås, Swede.
    Åkervall, Sigvard
    Södra Älvsborgs Sjukhus, Borås, Sweden.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Development and Validation of a Universal Measurement System for Measuring the Performance of Mammals2014Ingår i: International journal of system dynamics applications, ISSN 2160-9772, Vol. 3, nr 2Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Exercise wheels for mammals are commonly used as test systems in many medical research areas. Studies may be related to many different areas such as vitamins, hormones (as dopamine), and physical endurance. As research develops the scope and size of the studies increase and the requirements of the test system might change. In order to conduct the experiments effectively, there is a need to increase the number of test stations, and the test station may also be required to handle physically larger mammals. This study presents and validates a wireless system for endurance tests. The system was validated on mice and humans. It is scalable, and can be expandable up to 254 test stations. In the case of the exercise wheel with mice, the ADEA system was used as a reference. The initial validation was done by comparing the activity measured by both systems in mice with different hormone dopamine levels. The correlation coefficients between the systems estimated activity levels were in the range from 0.916 to 0.967. The new system enables quantitative measurements of the activity level using standard SI units (meters and seconds, respectively). In the validation with humans, runners were clocked by the system and manually. The lowest correlation coefficient obtained during these measurements was 0.864. Thus, both applications showed a high correlation with conventional methods.

  • 1849.
    Östberg, Micael
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Norgren, Mikael
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Intelligent Gripper2013Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Den mänskliga handen är en fantastisk universiell gripklo då den kan greppa objekt av okänd form, vikt och yta. De flesta gripklor i dagens industri måste vara specialgjorda och anpassas för varje applikation av ingenjörer och därmed behövs otaliga mantimmar för att få önskat beteende och repeterbarhet. Att kunna anpassa vissa av den mänskliga handens egenskaper till en robust industriell robotgripklo skulle utöka dess användarområde och lätta upp anpassningen för ingenjörer när den väl är installerad.

    Detta examensarbete diskuterar hur en robust intelligent gripklo har blivit utvecklat for industriellt bruk baserad på piezo sensorer som har förmågan att känna av glidning och initiell kontakt av objekt. Först, en experimentiell fungerande sensorprototyp utvecklades med hjälp av en förstärkningskrets och algoritmer implementerade i LabView. Därefter utvecklades en slutlig prototyp innehållandes ett signalkort, ett FPGA-kort, en enkel gripklo med linjärenheter och mer robusta sensorer.

    Examensarbetet tar vidare upp vilka delar som framgångsrikt blivit implementerade och vilka delar som behöver utvecklas ytterligare, testas och förbättras.

  • 1850.
    Öström, Erik
    Mälardalens högskola, Akademin för innovation, design och teknik.
    BUILDING AND EXPERIMENTALLYEVALUATING A SMART ANTENNA FOR LOWPOWER WIRELESS COMMUNICATION2010Självständigt arbete på avancerad nivå (magisterexamen), 30 poäng / 45 hpStudentuppsats (Examensarbete)
    Abstract [en]

    In wireless communication there is commonly much unnecessarycommunication made in directions not pointing towards the recipient. Normallyomni directional antennas are being used which sends the same amount ofenergy in all directions equally. This waste of energy reduces the lifetime ofbattery powered units and causes more traffic collisions than necessary. Oneway of minimizing this wasted energy and traffic collisions, is to use anothertype of antenna called “smart antenna”. These antennas can use selectableradiation patterns depending on the situation and thus drastically minimize theunnecessary energy waste. Smart antennas also provide the ability to sense thedirection of incoming signals which is favorable for physical layout mappingsuch as orientation.This thesis presents the prototyping of a new type of smart antenna called theSPIDA smart antenna. This antenna is a cheap to produce smart antennadesigned for the 2.4 GHz frequency band. The SPIDA smart antenna can usesixty-four different signal patterns with the control of six separate directionalmodes, amongst these patterns are six single direction patterns, an omnidirectionalsignal pattern and fifty-six combi-direction patterns. The thesispresents complete building instructions, evaluation data and functional driversfor the SPIDA smart antenna.

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