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  • 1.
    Abas, N.
    et al.
    University of Gujrat, Hafiz Hayat Campus, Gujrat, Pakistan.
    Kalair, A. R.
    COMSATS University Islamabad, Islamabad, Pakistan.
    Seyedmahmoudian, M.
    Swinburne University, Australia.
    Naqvi, M.
    Karlstad University.
    Campana, Pietro Elia
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Khan, N.
    COMSATS University Islamabad, Islamabad, Pakistan.
    Dynamic simulation of solar water heating system using supercritical CO2 as mediating fluid under sub-zero temperature conditions2019Ingår i: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 161, artikel-id 114152Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    CO2 is becoming increasingly important as a mediating fluid, and simulation studies are indispensable for corresponding developments. In this study, a simulation-based performance investigation of a solar water heating system using CO2 as a mediating fluid under sub-zero temperature condition is performed using the TRNSYS® software. The maximum performance is achieved at a solar savings fraction of 0.83 during July. The as lowest solar savingss fraction of 0.41 is obtained during December. The annual heat production of the proposed system under Fargo climate is estimated to be about 2545 kWh. An evacuated glass tube solar collector is designed, fabricated and tested for various climate conditions. Moreover, a detailed comparison of the system's performance at sub/supercritical and supercritical pressures shows that the annual heat transfer efficiency of the modeled system is 10% higher at supercritical pressure than at sub/supercritical pressures. This result can be attributd to the strong convection flow of CO2 caused by density inhomogeneities, especially in the near critical region. This condition resuls in high heat transfer rates.

  • 2.
    Abbaneo, Chiara
    et al.
    Ansaldo STS, Italy.
    Flammini, Francesco
    Ansaldo STS, Italy ; University of Naples ”Federico II”, Italy.
    Lazzaro, Armando
    Ansaldo STS, Italy.
    Marmo, Pietro
    Ansaldo STS, Italy.
    Mazzocca, Nicola
    Université “Federico II” di Napoli, Italy.
    Sanseviero, Angela
    Ansaldo STS, Italy.
    UML based reverse engineering for the verification of railway control logics2007Ingår i: Proceedings of International Conference on Dependability of Computer Systems, DepCoS-RELCOMEX 2006, IEEE , 2007, s. 3-10Konferensbidrag (Refereegranskat)
    Abstract [en]

    The Unified Modeling Language (UML) is widely used as a high level object oriented specification language. In this paper we present a novel approach in which reverse engineering is performed using UML as the modelling language used to achieve a representation of the implemented system. The target is the core logic of a complex critical railway control system, which was written in an application specific legacy language. UML perfectly suited to represent the nature of the core logic, made up by concurrent and interacting processes, using a bottom-up approach and proper modeling rules. Each process, in fact, was strictly related to the management of a physically (resp. logically) well distinguished railway device (resp. functionality). The obtained model deeply facilitated the static analysis of the logic code, allowing for at a glance verification of correctness and compliance with higher-level specifications, and opened the way to refactoring and other formal analyses. © 2006 IEEE.

  • 3.
    Abbas, Muhammad
    Mälardalens högskola, Akademin för innovation, design och teknik. ES (Embedded Systems).
    Variability Aware Requirements Reuse Analysis2020Ingår i: The 42nd International Conference on Software Engineering Companion ICSE'20, Seoul, South Korea: ACM , 2020Konferensbidrag (Refereegranskat)
    Abstract [en]

    Problem: The goal of a software product line is to aid quick and quality delivery of software products, sharing common features. Effectively achieving the above-mentioned goals requires reuse analysis of the product line features. Existing requirements reuse analysis approaches are not focused on recommending product line features, that can be reused to realize new customer requirements. Hypothesis: Given that the customer requirements are linked to product line features' description satisfying them: then the customer requirements can be clustered based on patterns and similarities, preserving the historic reuse information. New customer requirements can be evaluated against existing customer requirements and reuse of product line features can be recommended. Contributions: We treated the problem of feature reuse analysis as a text classification problem at the requirements-level. We use Natural Language Processing and clustering to recommend reuse of features based on similarities and historic reuse information. The recommendations can be used to realize new customer requirements.

  • 4.
    Abbas, Muhammad
    et al.
    Research Institutes of Sweden Västerås, Sweden.
    Inayat, Irum
    National University of Computer & Emerging Sciences Islamabad, Pakistan.
    Jan, Naila
    National University of Computer & Emerging Sciences Islamabad, Pakistan.
    Saadatmand, Mehrdad
    Research Institutes of Sweden Västerås, Sweden.
    Enoiu, Eduard Paul
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Daniel, Sundmark
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    MBRP: Model-based Requirements Prioritization Using PageRank Algorithm2019Ingår i: Asia-Pacific Software Engineering Conference APSEC 2019, 2019, s. 31-38, artikel-id 8945656Konferensbidrag (Refereegranskat)
    Abstract [en]

    Requirements prioritization plays an important role in driving project success during software development. Literature reveals that existing requirements prioritization approaches ignore vital factors such as interdependency between requirements. Existing requirements prioritization approaches are also generally time-consuming and involve substantial manual effort. Besides, these approaches show substantial limitations in terms of the number of requirements under consideration. There is some evidence suggesting that models could have a useful role in the analysis of requirements interdependency and their visualization, contributing towards the improvement of the overall requirements prioritization process. However, to date, just a handful of studies are focused on model-based strategies for requirements prioritization, considering only conflict-free functional requirements. This paper uses a meta-model-based approach to help the requirements analyst to model the requirements, stakeholders, and inter-dependencies between requirements. The model instance is then processed by our modified PageRank algorithm to prioritize the given requirements. An experiment was conducted, comparing our modified PageRank algorithm’s efficiency and accuracy with five existing requirements prioritization methods. Besides, we also compared our results with a baseline prioritized list of 104 requirements prepared by 28 graduate students. Our results show that our modified PageRank algorithm was able to prioritize the requirements more effectively and efficiently than the other prioritization methods.

  • 5.
    Abbas, Muhammad
    et al.
    RISE SICS, Research Institutes of Sweden, Västerås, Sweden.
    Inayat, Irum
    SERL, National University of Computer & Emerging Sciences, Islamabad, Pakistan.
    Saadatmand, Mehrdad
    RISE SICS, Research Institutes of Sweden, Västerås, Sweden.
    Jan, Naila
    SERL, National University of Computer & Emerging Sciences, Islamabad, Pakistan.
    Requirements dependencies-based test case prioritization for extra-functional properties2019Ingår i: ICST Workshop on Testing Extra-Functional Properties and Quality Characteristics of Software Systems ITEQS'19, 2019, s. 159-163Konferensbidrag (Refereegranskat)
    Abstract [en]

    The use of requirements’ information in testing is a well-recognized practice in the software development life cycle. Literature reveals that existing tests prioritization and selection approaches neglected vital factors affecting tests priorities, like interdependencies between requirement specifications. We believe that models may play a positive role in specifying these inter-dependencies and prioritizing tests based on these inter-dependencies. However, till date, few studies can be found that make use of requirements inter-dependencies for test case prioritization. This paper uses a meta-model to aid modeling requirements, their related tests, and inter-dependencies between them. The instance of this meta-model is then processed by our modified PageRank algorithm to prioritize the requirements. The requirement priorities are then propagated to related test cases in the test model and test cases are selected based on coverage of extra-functional properties. We have demonstrated the applicability of our proposed approach on a small example case.

  • 6.
    Abbas, Muhammad
    et al.
    RISE Research Institutes of Sweden.
    Rauf, Abdul
    RISE Research Institute of Sweden.
    Saadatmand, Mehrdad
    RISE Research Institute of Sweden.
    Enoiu, Eduard Paul
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Daniel, Sundmark
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Keywords-based test categorization for Extra-Functional Properties2020Ingår i: 4th International Workshop on Testing Extra-Functional Properties and Quality Characteristics of Software Systems ITEQS'20, 2020Konferensbidrag (Refereegranskat)
    Abstract [en]

    Categorizing existing test specifications can provide insights on coverage of the test suite to extra-functional properties. Manual approaches for test categorization can be time-consuming and prone to error. In this short paper, we propose a semi-automated approach for semantic keywords-based textual test categorization for extra-functional properties. The approach is the first step towards coverage-based test case selection based on extra-functional properties. We report a preliminary evaluation of industrial data for test categorization for safety aspects. Results show that keyword-based approaches can be used to categorize tests for extra-functional properties and can be improved by considering contextual information of keywords.

  • 7.
    Abbaspour Asadollah, Sara
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Bugs and Debugging of Concurrent and Multicore Software2016Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Ladda ner fulltext (pdf)
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  • 8.
    Abbaspour Asadollah, Sara
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Concurrency Bugs: Characterization, Debugging and Runtime Verification2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Concurrent software has been increasingly adopted in recent years, mainly due to the introduction of multicore platforms. However, concurrency bugs are still difficult to test and debug due to their complex interactions involving multiple threads (or tasks). Typically, real world concurrent software has huge state spaces. Thus, testing techniques and handling of concurrency bugs need to focus on exposing the bugs in this large space. However, existing solutions typically do not provide debugging information to developers (and testers) for understanding the bugs.

    Our work focuses on improving concurrent software reliability via three contributions: 1) An investigation of concurrent software challenges with the aim to help developers (and testers) to better understand concurrency bugs. We propose a classification of concurrency bugs and discuss observable properties of each type of bug. In addition, we identify a number of gaps in the body of knowledge on concurrent software bugs and their debugging. 2) Exploring concurrency related bugs in real-world software with respect to the reproducibility of bugs, severity of their consequence and effort required to fix them. Our findings here is that concurrency bugs are different from other bugs in terms of their fixing time and severity, while they are similar in terms of reproducibility. 3) A model for monitoring concurrency bugs and the implementation and evaluation of a related runtime verification tool to detect the bugs. In general, runtime verification techniques are used to (a) dynamically verify that the observed behaviour matches specified properties and (b) explicitly recognize understandable behaviors in the considered software. Our implemented tool is used to detect concurrency bugs in embedded software and is in its current form tailored for the FreeRTOS operating system. It helps developers and testers to automatically identify concurrency bugs and subsequently helps to reduce their finding and fixing time.

    Ladda ner fulltext (pdf)
    fulltext
  • 9.
    Abbaspour Asadollah, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Daniel, Sundmark
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Eldh, S.
    Ericsson AB, Kista, Sweden.
    Hansson, Hans
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    A Runtime Verification Tool for Detecting Concurrency Bugs in FreeRTOS Embedded Software2018Ingår i: Proceedings - 17th International Symposium on Parallel and Distributed Computing, ISPDC 2018, Institute of Electrical and Electronics Engineers Inc. , 2018, s. 172-179, artikel-id 8452035Konferensbidrag (Refereegranskat)
    Abstract [en]

    This article presents a runtime verification tool for embedded software executing under the open source real-time operating system FreeRTOS. The tool detects and diagnoses concurrency bugs such as deadlock, starvation, and suspension based-locking. The tool finds concurrency bugs at runtime without debugging and tracing the source code. The tool uses the Tracealyzer tool for logging relevant events. Analysing the logs, our tool can detect the concurrency bugs by applying algorithms for diagnosing each concurrency bug type individually. In this paper, we present the implementation of the tool, as well as its functional architecture, together with illustration of its use. The tool can be used during program testing to gain interesting information about embedded software executions. We present initial results of running the tool on some classical bug examples running on an AVR 32-bit board SAM4S. 

  • 10.
    Abbaspour Asadollah, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Daniel, Sundmark
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Hansson, Hans
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Runtime Verification for Detecting Suspension Bugs in Multicore and Parallel Software2017Ingår i: Proceedings - 10th IEEE International Conference on Software Testing, Verification and Validation Workshops, ICSTW 2017, 2017, s. 77-80Konferensbidrag (Refereegranskat)
    Abstract [en]

    Multicore hardware development increases the popularity of parallel and multicore software, while testing and debugging the software become more difficult, frustrating and costly. Among all types of software bugs, concurrency bugs are both important and troublesome. This type of bugs is increasingly becoming an issue, particularly due to the growing prevalence of multicore hardware. Suspension-based-locking bug is one type of concurrency bugs. This position paper proposes a model based on runtime verification and reflection technique in the context of multicore and parallel software to monitor and detect suspension-based-locking bugs. The model is not only able to detect faults, but also diagnose and even repair them. The model is composed of four layers: Logging, Monitoring, Suspension Bug Diagnosis and Mitigation. The logging layer will observe the events and save them into a file system. The monitoring layer will detect the presents of bugs in the software. The suspension bug diagnosis will identify Suspension bugs by comparing the captured data with the suspension bug properties. Finally, the mitigation layer will reconfigure the software to mitigate the suspension bugs. A functional architecture of a runtime verification tool is also proposed in this paper. This architecture is based on the proposed model and is comprised of different modules. 

  • 11.
    Abbaspour Asadollah, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. 7809198067.
    Enoiu, Eduard Paul
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Causevic, Adnan
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Daniel, Sundmark
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Hansson, Hans
    Mälardalens högskola, Akademin för innovation, design och teknik.
    A Runtime Verification based Concurrency Bug Detector for FreeRTOS Embedded SoftwareIngår i: Artikel i tidskrift (Övrigt vetenskapligt)
    Ladda ner fulltext (pdf)
    fulltext
  • 12.
    Abbaspour Asadollah, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Hansson, Hans
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Sundmark, Daniel
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Eldh, Sigrid
    Ericsson AB, Kista, Sweden.
    Towards Classification of Concurrency Bugs Based on Observable Properties2015Ingår i: Proceedings - 1st International Workshop on Complex Faults and Failures in Large Software Systems, COUFLESS 2015, 2015, s. 41-47Konferensbidrag (Refereegranskat)
    Abstract [en]

    In software engineering, classification is a way to find an organized structure of knowledge about objects. Classification serves to investigate the relationship between the items to be classified, and can be used to identify the current gaps in the field. In many cases users are able to order and relate objects by fitting them in a category. This paper presents initial work on a taxonomy for classification of errors (bugs) related to concurrent execution of application level software threads. By classifying concurrency bugs based on their corresponding observable properties, this research aims to examine and structure the state of the art in this field, as well as to provide practitioner support for testing and debugging of concurrent software. We also show how the proposed classification, and the different classes of bugs, relates to the state of the art in the field by providing a mapping of the classification to a number of recently published papers in the software engineering field.

  • 13.
    Abbaspour Asadollah, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Inam, Rafia
    Ericsson AB, Kista, Sweden.
    Hansson, Hans
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    A Survey on Testing for Cyber Physical System2015Ingår i: Testing Software and Systems: 27th IFIP WG 6.1 International Conference, ICTSS 2015, Sharjah and Dubai, United Arab Emirates, November 23-25, 2015, Proceedings, 2015, s. 194-207Konferensbidrag (Refereegranskat)
    Abstract [en]

    Cyber Physical Systems (CPS) bridge the cyber-world of computing and communications with the physical world and require development of secure and reliable software. It asserts a big challenge not only on testing and verifying the correctness of all physical and cyber components of such big systems, but also on integration of these components. This paper develops a categorization of multiple levels of testing required to test CPS and makes a comparison of these levels with the levels of software testing based on the V-model. It presents a detailed state-of-the-art survey on the testing approaches performed on the CPS. Further, it provides challenges in CPS testing.

  • 14.
    Abbaspour Asadollah, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. RISE Acreo AB, Sweden.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Gholamhosseini, H.
    Chalmers University of Technology, Gothenburg, Sweden.
    Naber, A.
    Chalmers University of Technology, Gothenburg, Sweden.
    Ortiz-Catalan, M.
    Chalmers University of Technology, Gothenburg, Sweden.
    Evaluation of surface EMG-based recognition algorithms for decoding hand movements2020Ingår i: Medical and Biological Engineering and Computing, ISSN 0140-0118, E-ISSN 1741-0444, Vol. 58, nr 1, s. 83-100Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Myoelectric pattern recognition (MPR) to decode limb movements is an important advancement regarding the control of powered prostheses. However, this technology is not yet in wide clinical use. Improvements in MPR could potentially increase the functionality of powered prostheses. To this purpose, offline accuracy and processing time were measured over 44 features using six classifiers with the aim of determining new configurations of features and classifiers to improve the accuracy and response time of prosthetics control. An efficient feature set (FS: waveform length, correlation coefficient, Hjorth Parameters) was found to improve the motion recognition accuracy. Using the proposed FS significantly increased the performance of linear discriminant analysis, K-nearest neighbor, maximum likelihood estimation (MLE), and support vector machine by 5.5%, 5.7%, 6.3%, and 6.2%, respectively, when compared with the Hudgins’ set. Using the FS with MLE provided the largest improvement in offline accuracy over the Hudgins feature set, with minimal effect on the processing time. Among the 44 features tested, logarithmic root mean square and normalized logarithmic energy yielded the highest recognition rates (above 95%). We anticipate that this work will contribute to the development of more accurate surface EMG-based motor decoding systems for the control prosthetic hands.

  • 15.
    Abbaspour Asadollah, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Saadatmand, Mehrdad
    SICS Swedish ICT, Västerås, Sweden.
    Eldh, Sigrid
    Ericsson AB, Kista, Sweden.
    Sundmark, Daniel
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Hansson, Hans
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    A Model for Systematic Monitoring and Debugging of Starvation Bugs in Multicore Software2016Ingår i: 2016 ASE Workshop on Specification, Comprehension, Testing and Debugging of Concurrent Programs SCTDCP2016, 2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    With the development of multicore hardware, concurrent, parallel and multicore software are becoming increasingly popular. Software companies are spending a huge amount of time and resources to nd and debug the bugs. Among all types of software bugs, concurrency bugs are also important and troublesome. This type of bugs is increasingly becoming an issue particularly due to the growing prevalence of multicore hardware. In this position paper, we propose a model for monitoring and debugging Starvation bugs as a type of concurrency bugs in multicore software. The model is composed into three phases: monitoring, detecting and debugging. The monitoring phase can support detecting phase by storing collected data from the system execution. The detecting phase can support debugging phase by comparing the stored data with starvation bug's properties, and the debugging phase can help in reproducing and removing the Starvation bug from multicore software. Our intention is that our model is the basis for developing tool(s) to enable solving Starvation bugs in software for multicore platforms.

  • 16.
    Abbaspour Asadollah, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Sundmark, Daniel
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Eldh, Sigrid
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. Ericsson AB, Kista, Sweden .
    Hansson, Hans
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Afza, Wasif
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    10 Years of research on debugging concurrent and multicore software: a systematic mapping study2017Ingår i: Software quality journal, ISSN 0963-9314, E-ISSN 1573-1367, Vol. 25, nr 1, s. 49-82Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Debugging – the process of identifying, localizing and fixing bugs – is a key activity in software development. Due to issues such as non-determinism and difficulties of reproducing failures, debugging concurrent software is significantly more challenging than debugging sequential software. A number of methods, models and tools for debugging concurrent and multicore software have been proposed, but the body of work partially lacks a common terminology and a more recent view of the problems to solve. This suggests the need for a classification, and an up-to-date comprehensive overview of the area. 

    This paper presents the results of a systematic mapping study in the field of debugging of concurrent and multicore software in the last decade (2005– 2014). The study is guided by two objectives: (1) to summarize the recent publication trends and (2) to clarify current research gaps in the field.

    Through a multi-stage selection process, we identified 145 relevant papers. Based on these, we summarize the publication trend in the field by showing distribution of publications with respect to year , publication venues , representation of academia and industry , and active research institutes . We also identify research gaps in the field based on attributes such as types of concurrency bugs, types of debugging processes , types of research  and research contributions.

    The main observations from the study are that during the years 2005–2014: (1) there is no focal conference or venue to publish papers in this area, hence a large variety of conferences and journal venues (90) are used to publish relevant papers in this area; (2) in terms of publication contribution, academia was more active in this area than industry; (3) most publications in the field address the data race bug; (4) bug identification is the most common stage of debugging addressed by articles in the period; (5) there are six types of research approaches found, with solution proposals being the most common one; and (6) the published papers essentially focus on four different types of contributions, with ”methods” being the type most common one.

    We can further conclude that there is still quite a number of aspects that are not sufficiently covered in the field, most notably including (1) exploring correction  and fixing bugs  in terms of debugging process; (2) order violation, suspension  and starvation  in terms of concurrency bugs; (3) validation and evaluation research  in the matter of research type; (4) metric  in terms of research contribution. It is clear that the concurrent, parallel and multicore software community needs broader studies in debugging.This systematic mapping study can help direct such efforts.

  • 17.
    Abbaspour Asadollah, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Sundmark, Daniel
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Eldh, Sigrid
    Ericsson AB, Kista, Sweden.
    Hansson, Hans
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Paul Enoiu, Eduard
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    A Study on Concurrency Bugs in an Open Source Software2016Ingår i: IFIP Advances in Information and Communication Technology, vol. 472, 2016, Vol. 472, s. 16-31Konferensbidrag (Refereegranskat)
    Abstract [en]

    Concurrent programming puts demands on software debugging and testing, as concurrent software may exhibit problems not present in sequential software, e.g., deadlocks and race conditions. In aiming to increase efficiency and effectiveness of debugging and bug-fixing for concurrent software, a deep understanding of concurrency bugs, their frequency and fixingtimes would be helpful. Similarly, to design effective tools and techniques for testing and debugging concurrent software understanding the differences between non-concurrency and concurrency bugs in real-word software would be useful.

  • 18.
    Abbaspour, Sara
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Electromyogram Signal Enhancement and Upper-Limb Myoelectric Pattern Recognition2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Att förlora en extremitet orsakar svårigheter i vår vardag. För att återfå förmågan till ett självständigt liv har artificiella händer och ben utvecklats. Handproteser kan kontrolleras av användaren genom aktiviteten hos återstående muskler ovanför amputationen. Elektromyogram (EMG) är en av de källor som kan användas till kontrollmetoder för handproteser. Yt-EMG är kraftfulla icke-invasiva verktyg som ger information om neuromuskulär aktivitet hos en specifik muskel, vilket är avgörande för dess användning att styra proteser. Komplexiteten hos signalen utgör dock en stor utmaning. EMG-mönsterigenkänning för att avkoda olika handrörelser är ett viktigt framsteg när det gäller kontroll av motoriserade proteser. Denna metod har potential att möjliggöra styrning av proteser genom att använda EMG-signalerna från muskelkontraktioner som insignal. Denna metod har dock ännu inte fått någon stor klinisk spridning. Olika algoritmer har utvecklats inom området för att avkoda olika rörelser; men utmaningen att identifiera olika handrörelser i olika faser kvarstår, och förbättringar inom dessa områden kan komma att öka funktionaliteten hos motoriserade proteser. Denna avhandling undersöker flera aspekter kring detta, först hur kvaliteten hos EMG-signaler kan förbättras genom att nya och avancerade filtreringstekniker. Fyra effektiva tillvägagångssätt (adaptivt neuro-fuzzy inference system-wavelet, artificiellt neuralt nätverk-wavelet, adaptiv subtraktion och automatiserad oberoende komponentanalys-wavelet) presenteras för att förbättra filtreringsprocessen för yt-EMG-signaler och effektivt eliminera EKG-störningar. Även offline-prestanda för olika EMG-baserade igenkänningsalgoritmer undersöks, däribland förmågan att klassificera olika handrörelser med sikte på att erhålla nya myoelektriska kontrollkonfigurationer som förbättrar igenkänningen. För att undersöka hur väl de myoelektriska mönsterigenkänningssalgoritmerna fungerar i verkliga situationer, har ett brett spektrum av myoelektriska algoritmer undersökts i realtid. 15 friska frivilliga försökspersoner har använt systemet och resultaten tyder på att linjär diskriminantanalys (LDA) och maximal sannolikhetsbedömning (MLE) är bättre än de andra klassificeringsmetoderna. Realtidsundersökningen visar också att förutom LDA och MLE, så är algoritmerna med flerlagersperception bättre än de övriga algoritmerna då de jämförs med avseende på klassificeringsnoggrannhet och beräkningshastighet.

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  • 19.
    Abbaspour, Sara
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Evaluation of surface EMG-based recognition algorithms for decoding hand movementsManuskript (preprint) (Övrigt vetenskapligt)
  • 20.
    Abbaspour, Sara
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Proposing Combined Approaches to Remove ECG Artifacts from Surface EMG Signals2015Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Elektromyografi (EMG) är ett verktyg som rutinmässigt används för en mängd olika applikationer inom många discipliner. Dock är denna signal oundvikligen kontaminerad av artefakter som kommer från olika källor. Elektrisk aktivitet av hjärtmuskln, elektrokardiogram (EKG), är en av störkällorna som påverkar EMG-signalerna på grund av närheten till hjärtat och som försämrar analysens tillförlitlig. Olika metoder har föreslagits för att ta bort EKG artefakter från yt-EMG-signaler men trots många försök att eliminera eller minska denna artefakt, kvarstår problemet med korrekt och effektivt brusreducering av EMG. I denna studie har vanliga metoder för brusundertryckning undersökts, såsom högpassfilter (HPF), gatingmetod, spikklippning, hybridteknik, subtraktionsmetod, oberoende komponentanalys (ICA), wavelet, wavelet-ICA, artificiella neurala nätverk (ANN), och adaptiv brusreducering (ANC) och adaptiv neuro fuzzy inference system (ANFIS). Metorderna har använts för att avlägsna EKG- artefakter från yt-EMG-signaler och deras noggrannhet och effektivitet har undersökts. HPF, gatingmetod och spikklippning är snabba; men de tar även bort relevant information från EMG-signalen. Hybridteknik och ANC är tidskrävande. Subtraktionsmetoden kräver kännedom om QRS-mönstret.Wavelettransformen lämnade kvar vissa artefakter i signalen, och avlägsnade även endel av den ursprungliga EMG-signalen. ICA kräver flerkanaliga signaler. Wavelet-ICA kräver inte flerkanaliga signaler, men är däremot användarberoende. ANN och ANFIS har bra prestanda, men det är möjligt att förbättra resultaten genom att kombinera dem med andra tekniker. För vissa tillämpningar av EMG-signaler såsom rehabilitering, rörelsekontroll och prediktion, är kvaliteten på EMG-signalerna mycket viktigt. Dessutom måste de artefaktreducerande metoderna vara i realtid och automatiska. Detta innebär att metoderna ANN-wavelet, adaptiv subtraktion och automatiserad wavelet-ICA rekommenderas för effektiv eliminering av EKG-artefakter från yt-EMG-signaler. För att jämföra resultaten av de undersökta och föreslagna metoderna i denna studie, har rena EMG-signaler från biceps och delta-muskler, samt EKG-artefakter från stora bröstmuskeln spelats in från fem friska personer. För att skapa 10-kanaliga brusiga EMG-signaler har de inspelade EKG-artefakterna adderats till de rena EMG-signalerna. De olika artefaktreduceringsmetoderna har även tillämpats på 10 kanaler verkliga EMG signaler med artefakter, från stora bröstmuskeln på vänster sida. Utvärderingskriterier såsom signal-brusförhållandet, relativta felet, korrelationskoefficienten, förfluten tid och effektspektrumstäthet har använts för att utvärdera de föreslagna metoderna. Prestandan hos den föreslagna ANN-wavelet metoden befanns överlägsen de andra metoderna med ett signalbrusförhållande på 15,53, relativt fel på 0,01 och korrelationskoefficient på 0,98.

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  • 21.
    Abbaspour, Sara
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Surface EMG signal processing: Removing ECG interferences and classifying hand movements2017Ingår i: Medicinteknikdagarna 2017 MTD 2017, Västerås, Sweden, 2017Konferensbidrag (Refereegranskat)
  • 22.
    Abbaspour, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Chiew, Thiam Kian
    University of Malaya, Kuala Lumpur, Malaysia .
    Web Service Response Time Monitoring: Architecture and Validation2011Ingår i: Communications in Computer and Information Science Volume 164 CCIS, 2011, 2011, s. 276-282Konferensbidrag (Refereegranskat)
    Abstract [en]

    Web services are used in many Web applications in order to save time and cost during software development process. To peruse Web service response time, a suitable tool is needed to automate the measurement of the response time. However, not many suitable tools are available for automatic measurement of response time. This research is carried out in the context of quality of Web services in order to measure and visualize Web service response time. The method proposed in this research for accomplishing this goal is based on creating a proxy for connecting to the required Web service, and then calculating the Web services response time via the proxy. A software tool is designed based on the proposed method in order to guide the implementation that is still in progress. The tool can be validated through empirical validation using three test cases for three different Web service access situations.

  • 23.
    Abbaspour, Sara
    et al.
    Amirkabir University of Technology, Tehran, Iran.
    Fallah, Ali
    Amirkabir University of Technology, Tehran, Iran.
    A Combination Method for Electrocardiogram Rejection from Surface Electromyogram2014Ingår i: Open Biomedical Engineering Journal, ISSN 1874-1207, E-ISSN 1874-1207, Vol. 8, nr 1, s. 13-19Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The electrocardiogram signal which represents the electrical activity of the heart provides interference in the recording of the electromyogram signal, when the electromyogram signal is recorded from muscles close to the heart. Therefore, due to impurities, electromyogram signals recorded from this area cannot be used. In this paper, a new method was developed using a combination of artificial neural network and wavelet transform approaches, to eliminate the electrocardiogram artifact from electromyogram signals and improve results. For this purpose, contaminated signal is initially cleaned using the neural network. With this process, a large amount of noise can be removed. However, low-frequency noise components remain in the signal that can be removed using wavelet. Finally, the result of the proposed method is compared with other methods that were used in different papers to remove electrocardiogram from electromyogram. In this paper in order to compare methods, qualitative and quantitative criteria such as signal to noise ratio, relative error, power spectrum density and coherence have been investigated for evaluation and comparison. The results of signal to noise ratio and relative error are equal to 15.6015 and 0.0139, respectively.

  • 24.
    Abbaspour, Sara
    et al.
    Amirkabir University of technology,Tehran, Iran.
    Fallah, Ali
    Amirkabir University of technology,Tehran, Iran.
    Removing ECG Artifact from the Surface EMG Signal Using Adaptive Subtraction Technique2014Ingår i: Biomedical Physics and Engineering, ISSN 2251-7200, Vol. 4, nr 1, s. 33-38Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: The electrocardiogram artifact is a major contamination in the electromyogram signals when electromyogram signal is recorded from upper trunk muscles and because of that the contaminated electromyogram is not useful. Objective: Removing electrocardiogram contamination from electromyogram signals. Methods: In this paper, the clean electromyogram signal, electrocardiogram artifact and electrocardiogram signal were recorded from leg muscles, the pectoralis major muscle of the left side and V4, respectively. After the pre-processing, contaminated electromyogram signal is simulated with a combination of clean electromyogram and electrocardiogram artifact. Then, contaminated electromyogram is cleaned using adaptive subtraction method. This method contains some steps; (1) QRS detection, (2) formation of electrocardiogram template by averaging the electrocardiogram complexes, (3) using low pass filter to remove undesirable artifacts, (4) subtraction. Results: Performance of our method is evaluated using qualitative criteria, power spectrum density and coherence and quantitative criteria signal to noise ratio, relative error and cross correlation. The result of signal to noise ratio, relative error and cross correlation is equal to 10.493, 0.04 and %97 respectively. Finally, there is a comparison between proposed method and some existing methods. Conclusion: The result indicates that adaptive subtraction method is somewhat effective to remove electrocardiogram artifact from contaminated electromyogram signal and has an acceptable result.

  • 25.
    Abbaspour, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Fallah, Ali
    Amirkabir University of Technology, Tehran, Iran.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Gholamhosseini, Hamid
    Auckland University of Technology, Auckland, New Zealand.
    A Novel Approach for Removing ECG Interferences from Surface EMG signals Using a Combined ANFIS and Wavelet2016Ingår i: Journal of Electromyography & Kinesiology, ISSN 1050-6411, E-ISSN 1873-5711, Vol. 26, s. 52-59Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In recent years, the removal of electrocardiogram (ECG) interferences from electromyogram (EMG) signals has been given large consideration. Where the quality of EMG signal is of interest, it is important to remove ECG interferences from EMG signals. In this paper, an efficient method based on a combination of adaptive neuro-fuzzy inference system (ANFIS) and wavelet transform is proposed to effectively eliminate ECG interferences from surface EMG signals. The proposed approach is compared with other common methods such as high-pass filter, artificial neural network, adaptive noise canceller, wavelet transform, subtraction method and ANFIS. It is found that the performance of the proposed ANFIS-wavelet method is superior to the other methods with the signal to noise ratio and relative error of 14.97 dB and 0.02 respectively and a significantly higher correlation coefficient (p < 0.05).

  • 26.
    Abbaspour, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Gholamhosseini, H.
    School of Engineering, Auckland University of TechnologyAuckland, New Zealand .
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Evaluation of wavelet based methods in removing motion artifact from ECG signal2015Ingår i: IFMBE Proceedings, 2015, s. 1-4Konferensbidrag (Refereegranskat)
    Abstract [en]

    Accurate recording and precise analysis of the electrocardiogram (ECG) signals are crucial in the pathophysiological study and clinical treatment. These recordings are often corrupted by different artifacts. The aim of this study is to propose two different methods, wavelet transform based on nonlinear thresholding and a combination method using wavelet and independent component analysis (ICA), to remove motion artifact from ECG signals. To evaluate the performance of the proposed methods, the developed techniques are applied to the real and simulated ECG data. The results of this evaluation are presented using quantitative and qualitative criteria. The results show that the proposed methods are able to reduce motion artifacts in ECG signals. Signal to noise ratio (SNR) of the wavelet technique is equal to 13.85. The wavelet-ICA method performed better with SNR of 14.23.

  • 27.
    Abbaspour, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Electromyography signal analysis: Electrocardiogram artifact removal and classifying hand movements2018Ingår i: World Congress on Medical Physics and Biomedical Engineering IUPESM, 2018Konferensbidrag (Refereegranskat)
  • 28.
    Abbaspour, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Gholamhosseini, Hamid
    Auckland University of Technology, New Zealand.
    ECG Artifact Removal from Surface EMG Signal Using an Automated Method Based on Wavelet-ICA2015Ingår i: Studies in Health Technology and Informatics, Volume 211, 2015, s. 91-97Konferensbidrag (Refereegranskat)
    Abstract [en]

    This study aims at proposing an efficient method for automated electrocardiography (ECG) artifact removal from surface electromyography (EMG) signals recorded from upper trunk muscles. Wavelet transform is applied to the simulated data set of corrupted surface EMG signals to create multidimensional signal. Afterward, independent component analysis (ICA) is used to separate ECG artifact components from the original EMG signal. Components that correspond to the ECG artifact are then identified by an automated detection algorithm and are subsequently removed using a conventional high pass filter. Finally, the results of the proposed method are compared with wavelet transform, ICA, adaptive filter and empirical mode decomposition-ICA methods. The automated artifact removal method proposed in this study successfully removes the ECG artifacts from EMG signals with a signal to noise ratio value of 9.38 while keeping the distortion of original EMG to a minimum.

  • 29.
    Abdalsalam Noman, Riam
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Alqaisy, Ahmad
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Design av hörnväggfixtur2017Självständigt arbete på grundnivå (högskoleexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
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  • 30.
    Abdelkarim, Sofia
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Hasan Hawre, Hazhwan
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Kartläggning av ergonomin i en produktionscell: Med utformningsförslag för en ergonomisk arbetsplats2016Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    ABSTRACT

    Purpose: The aim of the work is to map the ergonomics in a production cell and propose and compare the solutions to identified problems. In order to identify the problem and come up with some solutions, these questions have been answered.• What factors lead to operations that are harmful to the body?• How can a production cell be designed to be more ergonomic for employees?• What are the advantages / disadvantages of ergonomics in a production company?

     

    Method: To perform the study and achieve the purpose of the work, the authors used a case study company where observations were made in parallel with a literature review mainly on ergonomics variety of analysis and quality. The case study company has been used as the basis for the case study where ergonomics are mapped by means of observations, interviews and data that were analyzed by means of literature study done in parallel.

    Study results: The study resulted in a survey of ergonomics in a production cell at the case study company and 5 different suggestions for improvement. The production cell on the case study company is a red cell today, which means that the production cell is in a non-accepted position and in need for urgent changes in ergonomics. Factors leading to bad ergonomics and a non-accepted position as Volvo's requirements have been identified. Many heavy lifting and many torque is what has the highest negative impact on the working environment and ergonomics. Lack of adequate lifting tools have led to those not used in the production cell today. This leads to repetitive work and encumbrance at the case study company. Further, also the working height of the paths contributed to an increased workload as operators are in an unnatural posture. All of these factors are the basis of the 5 suggestions for improvement as the study also resulted in. New custom lifting tools, job rotation, reverse the order of the court, new packaging and pallet to the gears and the robot turn. All these proposed solutions lead to reduced stress and improved ergonomics in the production cell as manual lifting and twists are reduced. The solutions also leads to the production cell shifting from a non-accepted position with demands of urgent change to a yellow production cell that requires an action plan for the future.

     

    Implications: The aim of this study was to map the ergonomics in a production cell. With the study in hand, a conclusion is drawn that the aim has been achieved when all three of the questions have been addressed. Factors leading to poor ergonomics are identified. As well the advantages and disadvantages of investing in ergonomics identified and how production cells should be formed. With this information in mind, a number of proposed solutions have been developed.

     

    Recommendations: Further studies on the subject are recommended to increase knowledge and interest. It may be appropriate to carry out more case studies at more industries to strengthen the study’s results and generalizability. Furthermore, studies are recommended where the entire work environment is studied and not only physical ergonomics. By studying the whole working environment and the many factors that interact it can lead to a greater force being created for higher efficiency and quality in production.

     

    Keywords: Ergonomics, Ergonomics, Work, Volvo CE, Load, Lifting Tools, Body Injury, Advantages, Improvements, Quality

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  • 31.
    Abdelki, Tibelya
    Mälardalens högskola, Akademin för innovation, design och teknik.
    En start för att uppnå ett så funktionellt och internt materialflöde som möjligt: En fallstudie om hur man kan reducera slöseri med hjälp av lean verktyg2020Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    I dagens tuffa tillverkningsindustri är det avstor vikt att företag ständigt kan utvecklas och ef-fektiviseras för att öka möjligheterna till att konkurrera med andra företag. En av dem betydande faktorerna för att kunna effektivisera företaget är att logistiken fungerar bra i praktiken samt att man reducerar internt slöseri.

    Syftet med studien är att upplysa om de brister som tagit plats i verkligheten ute på ett bygge hos ett företag. Skapa en bild av hur materialhanteringen fungerar i produktionen samt komma med idéer och förslag på förbättringar för att minska produktionsstörningar och onödig hantering av byggmaterial så att produktionen flyter på bättre. Det är tänkt att genomföras genom att försöka reducera slöseri med bland annat hjälp av lean verktyg. Målet med denna studie är att identifiera hur förbättringar i materialhantering kan göras med hjälp av lean production verktyg genom att besvara följande frågor:

    • Vilka faktorer fungerar mindre bra i produktionen?
    • Hur fungerar materialhanteringen i praktiken?
    • Vilka lean production verktyg är lämpliga för att förhindra att internt slöseri förekommer i produktionen?

    Uppsatsens empiriska data kommer från en fältstudie som har gjorts på ett projekt där det har byggts en skola på cirka 50000 kvadratmeter. Den teoretiska referensramen utgår bland annat utifrån verktyg från lean production för att hjälpa företaget reducera det slöseri som uppkom under studiens gång. Slöserierna har dokumenterats genom intervjuer, bilder med motiveringar samt en analys som förklarar vilka hjälpmedel som kan användas för bästa lösning.

    Slutligen, projektet har fungerat bra i praktiken men, det går alltid att utvecklas för att öka företagets konkurrenskraft. Inom den här fallstudien hade företaget behövt minimera slöseri för att få bättre flyt på produktionen genom att använda sig av lean production verktyg, en in och utvändig arbetsplatsdispositionsplan för en djupgående planering av logistikhanteringen och en välutvecklad samordningsplan mellan projektörer och projektledare.

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  • 32.
    Abdi, Sade
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Rathmaya, Noureddine
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Managing employees and promoting internal communication during change: A case study of change management at MTR Tunnelbanan AB2017Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
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  • 33.
    Abdul-Ahad, Amir Stefan
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Cürüklü, Baran
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Mahmoud, W. A.
    Al-Isra Private University, Amman, Jordan.
    Robust distance-based watermarking for digital image2008Ingår i: Proceedings of the 2008 International Conference on Security and Management, SAM 2008, 2008, s. 404-409Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, an algorithm is developed to invisibly watermark a cover object (color image) using watermark object (iconic image). The algorithm is based on the distances among the addresses of values of the cover object. These distances use to make the embedding. The order of manipulating these distances are specified by the values of the watermark data which is dealt with serially. The algorithm serves and achieves self encryption key. Each watermark object has its unique pattern of distances at different possible lengths of distance bits. This enhances the complexity of sequential embedding. The algorithm is tested using direct and single level and double level of Two-Dimensional Discrete Wavelet Transform (2D DWT) embeddings. Two important issues are addressed. Firstly is to achieve a high Peak Signal to Noise Ratio (PSNR). The ratio was found to increase with an increasing of distance bits. Secondly is that the watermarked object retains the same properties of cover object. The algorithm shows resisting and withstanding against the most important attacks. Some of these include the lossy compression, blurring, resize and some types of Noise.

  • 34. Abdul-Ahad, Amir Stefan
    et al.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Larsson, Thomas
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Mahmoud, Waleed A.
    Robust Distance-Based Watermarking for Digital Video2008Ingår i: Proceedings of The Annual SIGRAD Conference, Stockholm, 2008Konferensbidrag (Refereegranskat)
  • 35.
    Abdul-Ahad, Amir Stefan
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Çürüklü, Baran
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Folke, Mia
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Indirect Wavelet-Based Cardio Arrhythmia Detection Algorithm2008Ingår i: Medicinteknikdagarna, Gothenburg, Sweden, 2008, s. 14-15Konferensbidrag (Refereegranskat)
  • 36.
    Abduljalil, Vian
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Databasreplikering av kunddata i en DMZ miljö2013Självständigt arbete på grundnivå (högskoleexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
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  • 37.
    Abdullah, Syed Md Jakaria
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Moghaddami Khalilzad, Nima
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Behnam, Moris
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Nolte, Thomas
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Towards Implementation of Virtual-Clustered Multiprocessor Scheduling in Linux2013Ingår i: Proceedings of the 8th IEEE International Symposium on Industrial Embedded Systems, SIES 2013, 2013, s. 97-100Konferensbidrag (Refereegranskat)
    Abstract [en]

    Cluster based multiprocessor scheduling can be seen as a hybrid approach combining benefits of both partitioned and global scheduling. Virtual clustering further enhances it by providing dynamic cluster resource allocation and applying hierarchical scheduling techniques. Over the years, the study of virtual cluster scheduling has been limited to theoretical analysis. In this paper, we present our initial ideas about implementing virtual cluster scheduling in Linux. The purpose of this implementation is twofold: (i) we would like to demonstrate the feasibility of its implementation in an operating system, without modifying the kernel source code, (ii) we present practical insights on the overhead of implementing this framework.

  • 38.
    Abecassis-Moedas, Celine
    et al.
    Univ Catolica Portuguesa, Catolica Lisbon Sch Business & Econ, Lisbon, Portugal.
    Ben Mahmoud-Jouini, Sihem
    HEC Paris, Innovat & Entrepreneurship Ctr, Paris, France.
    Dell'Era, Claudio
    Politecn Milan, Dept Management Econ & Ind Engn, Milan, Italy.
    Manceau, Delphine
    Univ Penn, Wharton Sch, Philadelphia.
    Verganti, Roberto
    Politecnico di Milano.
    Key resources and internationalization modes of creative knowledge-intensive business services: The case of design consultancies2012Ingår i: Creativity and Innovation Management, ISSN 0963-1690, E-ISSN 1467-8691, Vol. 21, nr 3, s. 315-331Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the knowledge economy, knowledge-intensive business services (KIBS) are a key driver for innovation and competitiveness. The internationalization of these businesses raises challenges given their specificities such as knowledge intensity, the importance of customer interaction and intimacy in service delivery. This paper focuses on design consultancies as a specific type of creative KIBS for which these characteristics are emphasized. The objective of this research is to analyse the resources leveraged by the firms to compete internationally. It is based on 11 case studies of design consultancies located in five different countries (France, Italy, Portugal, Spain and the UK) that were selected for their capacity to perform at the international level for several years. The paper advances three internationalization modes depending on contingent variables and focusing on specific resources that enable international competitiveness: star-based, process-based and glocality-based. In star-based creative KIBS, the individual designer has developed a reputation that attracts customers internationally, operating as a brand. In process-based creative KIBS, the reputation of a collective creative process attracts clients from other countries. In glocality-based creative KIBS, the geographical proximity obtained by opening international offices helps to develop a close understanding of the client through frequent interactions, and also to know the client's market well and to better understand local codes and signs. These modes complement those presented in the existing internationalization literature which takes the peculiarities of creative KIBS into consideration.

  • 39.
    Abid, Ali
    et al.
    Mälardalens högskola, Institutionen för innovation, design och produktutveckling. Mälardalens högskola, Akademin för innovation, design och teknik.
    Roback, Joel
    Mälardalens högskola, Institutionen för innovation, design och produktutveckling.
    Produktutveckling för Cate & Nelson Design: Framtagning av möbel2008Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats/Examensarbete
    Abstract [sv]

    Denna rapport behandlar examensarbete utfört för industridesignföretaget Cate & Nelson Design. Företaget ligger i Eskilstuna och jobbar i huvudsakligen med möbeldesign och inredningsprodukter. Projektgruppensuppgift har varit att ta fram en ny möbel för företaget och arbetet har omfattat utveckling av hela produkten från idé till prototyp.

    Ladda ner fulltext (pdf)
    FULLTEXT01
  • 40.
    Abrahamsson, Alexandra
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Arbetsmiljöarbetet på SverigesBostadsrättsCentrum: Vad ändringarna i arbetsmiljölagen innebär2010Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This diploma work was performed because the company Sveriges BostadsrättsCentrum, with the abbreviation SBC, had a need to gain insight into how changes in the Work Environment Act and related regulations which took effect January 1, 2009 affecting their work with the work environment. The changes mean that the client may hand over his work environment responsibilities to a contractor and that he has to select so-called building work environment co-ordinators. At SBC they are working as representatives for tenant-owner's association when a construction is about to be carried out. The purpose was to ascertain how changes may affect the work at SBC. The diploma work intends to educate the staff at SBC how work with the work environment would look like if they met the regulatory requirements. The main issue that the diploma work deals with is whether SBC has the responsibility to select a building work environment co-ordinator for the planning and projecting before the contractor takes over responsibility for the work environment. Questions were answered by information from the Work Environment Act, AFS 1999:3 and other material from the Work Environment Authority. Two interviews with staff at the Work Environment Authority were also held. One of the conclusions drawn from the diploma work is that it’s the client who will select a building work environment co-ordinator for the planning and projecting. That should be done as soon as the planning and projecting has begun. The planning and projecting usually begins before the main contractor takes over responsibility for the work environment as the employee. It is not clear that SBC will take on the client’s responsibility to select a building work environment co-ordinator for the planning and projecting in the early planning, before the contractor takes on responsibility and there are several ways to do this.

    Ladda ner fulltext (pdf)
    FULLTEXT01
  • 41.
    Abrahamsson, H.
    et al.
    RISE, SICS, Germany.
    Abdesslem, F. B.
    RISE, SICS, Germany.
    Ahlgren, B.
    RISE, SICS, Germany.
    Brunstrom, A.
    Karlstad University, Sweden.
    Marsh, I.
    RISE, SICS, Germany.
    Björkman, Mats
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Connected Vehicles in Cellular Networks: Multi-Access Versus Single-Access Performance2018Ingår i: TMA 2018 - Proceedings of the 2nd Network Traffic Measurement and Analysis Conference, Institute of Electrical and Electronics Engineers Inc. , 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    Connected vehicles can make roads traffic safer and more efficient, but require the mobile networks to handle time-critical applications. Using the MONROE mobile broadband measurement testbed we conduct a multi-access measurement study on buses. The objective is to understand what network performance connected vehicles can expect in today's mobile networks, in terms of transaction times and availability. The goal is also to understand to what extent access to several operators in parallel can improve communication performance. In our measurement experiments we repeatedly transfer warning messages from moving buses to a stationary server. We triplicate the messages and always perform three transactions in parallel over three different cellular operators. This creates a dataset with which we can compare the operators in an objective way and with which we can study the potential for multi-access. In this paper we use the triple-access dataset to evaluate single-access selection strategies, where one operator is chosen for each transaction. We show that if we have access to three operators and for each transaction choose the operator with best access technology and best signal quality then we can significantly improve availability and transaction times compared to the individual operators. The median transaction time improves with 6% compared to the best single operator and with 61% compared to the worst single operator. The 90-percentile transaction time improves with 23% compared to the best single operator and with 65% compared to the worst single operator.

  • 42.
    Abrahamsson, Henrik
    et al.
    Swedish Inst of Computer Science, Kista, Sweden .
    Ahlgren, Bengt
    Swedish Inst of Computer Science, Kista, Sweden .
    Using Empirical Distributions to Characterize Web Client Traffic and to Generate Synthetic Traffic2000Ingår i: Conference Record / IEEE Global Telecommunications ConferenceVolume 1, 2000, 2000, s. 428-433Konferensbidrag (Refereegranskat)
    Abstract [en]

    We model a web client using empirical probability distributions for user clicks and transferred data sizes. By using a heuristic threshold value to distinguish user clicks in a packet trace we get a simple method for analyzing large packet traces in order to get information about user OFF times and amount of data transferred due to a user click. We derive the empirical probability distributions from the analysis of the packet trace. The heuristic is not perfect, but we believe it is good enough to produce a useful web client model. We use the empirical model to implement a web client traffic generator. The characteristics of the generated traffic is very close to the original packet trace, including self-similar properties.

  • 43.
    Abrahamsson, Henrik
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Ahlgren, Bengt
    SICS.
    Alonso, Juan
    Andersson, Anders
    SICS.
    Kreuger, Per
    SICS.
    A Multi Path Routing Algorithm for IP Networks Based on Flow Optimisation2002Ingår i: Proceedings of the Third International Workshop on Quality of Future Internet Services / [ed] Burkhard Stiller, Springer Berlin/Heidelberg, 2002, s. 135-144Konferensbidrag (Refereegranskat)
  • 44.
    Abrahamsson, Henrik
    et al.
    Swedish Institute of Computer Science.
    Björkman, Mats
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Robust Traffic Engineering using L-balanced Weight-Settings in OSPF/IS-IS2009Ingår i: Proceedings of the 2009 6th International Conference on Broadband Communications, Networks and Systems, BROADNETS 2009, 2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    Internet traffic volumes continue to grow at a great rate, now pushed by video and TV distribution in the networks. This brings up the need for traffic engineering mechanisms to better control the traffic. The objective of traffic engineering is to avoid congestion in the network and make good use of available resources by controlling and optimising the routing function. The challenge for traffic engineering in IP networks is to cope with the dynamics of Internet traffic demands. Today, the main alternative for intra-domain traffic engineering in IP networks is to use different methods for setting the weights in the routing protocols OSPF and IS-IS. In this paper we revisit the weight setting approach to traffic engineering but with focus on robustness. We propose I-balanced weight settings that route the traffic on the shortest paths possible but make sure that no link is utilised to more than a given level I. This gives efficient routing of traffic and controlled spare capacity to handle unpredictable changes in traffic. We present a heuristic search method for finding I-balanced weight settings and show that it works well in real network scenarios

  • 45.
    Abrahamsson, Henrik
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Björkman, Mats
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Robust Traffic Engineering using L-balanced Weight-Settings in OSPF/IS-IS2008Övrigt (Övrigt vetenskapligt)
  • 46.
    Abrahamsson, Henrik
    et al.
    Swedish Institute of Computer Science, Kista, Sweden.
    Gunnar, Anders
    Swedish Institute of Computer Science, Kista, Sweden.
    Traffic Engineering in Ambient Networks: Challenges and Approaches2004Konferensbidrag (Refereegranskat)
  • 47.
    Abrahamsson, Henrik
    et al.
    SICS AB, Kista, Sweden .
    Hagsand, Olof
    Dynarc AB, Kista, Sweden .
    Marsh, Ian
    SICS AB, Kista, Sweden .
    TCP over High Speed Variable Capacity Links: A Simulation Study for Bandwidth Allocation2002Ingår i: Protocols for High Speed Networks Workshop, 2002, s. 117-129Konferensbidrag (Refereegranskat)
  • 48.
    Abram, Sebastian
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Transportoptimering för Husmuttern AB2016Självständigt arbete på grundnivå (högskoleexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This report aims to serve as a logistical foundation for Husmuttern AB. This logistic foundation is defined by a transport solution, a loading solution that is associated with the transport, and a stock proposal for the elements. Husmuttern AB is a newly started company that has developed a new concept of modular housing, which will be built by order.The modular houses will be built by assembling prefabricated parts such as ceilings, walls, foundations and other elements. The advantage of building houses with prefabricated pieces is that the pieces themselves can hold a higher quality when prefabricated, than the pieces fabricated on the construction site, which results in a house that is built in a short matter of time, with high quality. Most of the elements will be prefabricated at Husmuttern’s micro factories.To make the prefabrication, construction and assembly of the houses possible, it is required that there is an efficient transport solution that transports all the necessary goods from retailers to the warehouse, micro-factory and construction site. The purpose of this work is to propose a suitable and efficient transport solution based on the weight and dimensions of the elements that have to be transported.This report is presenting solutions for these problems, where the solutions are assured by calculations that proves that the suggested transport is capable to deliver all necessary elements, and able of loading and unloading all the elements based on their weight and dimensions. A clear proposal on the stock solution for all elements is also presented in the report.The result of this work is considered as successful, due to the ensured transport method, loading method, and the suggested stock and transport partner. Thanks to these fundamental results, a foundation to the logistic solution is created and it is now possible to further develop the logistics, in order to achieve a complete logistics solution for Husmuttern AB.

    Ladda ner fulltext (pdf)
    Examensarbete Logistikoptimering
  • 49.
    Abubaker, J.
    et al.
    SLU.
    Odlare, Monica
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Pell, M.
    SLU.
    Nitrous Oxide Production from Soils Amended with Biogas Residues and Cattle Slurry2013Ingår i: Journal of Environmental Quality, ISSN 0047-2425, E-ISSN 1537-2537, Vol. 42, nr 4, s. 1046-1058Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The amount of residues generated from biogas production has increased dramatically due to the worldwide interest in renewable energy. A common way to handle the residues is to use them as fertilizers in crop production. Application of biogas residues to agricultural soils may be accompanied with environmental risks, such as increased N2O emission. In 24-d laboratory experiments, N2O dynamics and total production were studied in arable soils (sandy, clay, and organic) amended with one of two types of anaerobically digested biogas residues (BR-A and BR-B) generated from urban and agricultural waste and nondigested cattle slurry (CS) applied at rates corresponding to 70 kg NH4+-N ha(-1). Total N2O-N losses from the sandy soil were higher after amendment with BR-B (0.32 g N2O-N m(-2)) than BR-A or CS (0.02 and 0.18 g N2O-N m(-2), respectively). In the clay soil, N2O-N losses were very low for CS (0.02 g N2O-N m(-2)) but higher for BR-A and BR-B (0.25 and 0.15 g N2O-N m(-2), respectively). In the organic soil, CS gave higher total N2O-N losses (0.31 g N2O-N m(-2)) than BR-A or BR-B (0.09 and 0.08 g N2O-N m(-2), respectively). Emission peaks differed considerably between soils, occurring on Day 1 in the organic soil and on Days 11 to 15 in the sand, whereas in the clay the peak varied markedly (Days 1, 6, and 13) depending on residue type. In all treatments, NH4+ concentration decreased with time, and NO3- concentration increased. Potential ammonium oxidation and potential denitrification activity increased significantly in the amended sandy soil but not in the organic soil and only in the clay amended with CS. The results showed that fertilization with BR can increase N2O emissions and that the size is dependent on the total N and organic C content of the slurry and on soil type. In conclusion, the two types of BR and the CS are not interchangeable regarding their effects on N2O production in different soils, and, hence, matching fertilizer type to soil type could reduce N2O emissions. For instance, it could be advisable to avoid fertilization of organic soils with CS containing high amounts or organic C and instead use BR. In clay soil, however, the risk of N2O emissions could be lowered by choosing a CS.

  • 50. Abugessaisa, Imad
    et al.
    Sivertun, Åke
    Le Duc, Michael
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    A systemic view on Swedish traffic road accident data acquisition system2007Konferensbidrag (Refereegranskat)
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