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  • 151.
    Adolfsson, Marie
    Mälardalen University, School of Education, Culture and Communication.
    Att bryta heteronormen redan i förskolan: En undersökning av huruvida bilderböcker som bryter mot heteronormen används i förskolan och hur utbudet ser ut2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I denna uppsats har medvetenheten kring begreppet heteronorm i förskolan undersökts genom intervjuer med pedagoger på tre olika förskolor. Även utbudet av bilderböcker som bryter mot heteronormen har undersökts och en inventering har genomförts. Syftet var att få en insyn i hur pedagoger tänker kring frågan, om de använder sig av någon barnlitteratur som bryter mot heteronormen, och hur detta utbud av heteronormbrytande bilderböcker ser ut.

           I uppsatsen har det framkommit att medvetenheten kring begreppet heteronorm bland de deltagande pedagogerna är låg. Man ser sig som öppen när det gäller människor som bryter mot heteronormen, men man ser inget större behov av att arbeta med området när man inte har något barn som har samkönade föräldrar. Vad gäller bilderböcker som bryter mot heteronormen, ges majoriteten ut av bokförlag som har specialiserat sig på böcker som bryter mot normer, och endast ett fåtal har kommit ut på något större, mer allmänt, förlag.

           Slutsatsen är att det behövs kunskap hos pedagogerna i förskolan, för att de ska få en förståelse för vad heteronormen innebär, och varför man bör arbeta med det tidigt, då den saknas i både lärarutbildning och fortbildning som det ser ut nu.

  • 152. Adolfsson, Petra
    et al.
    Dobers, Peter
    Mälardalen University, School of Business, Society and Engineering.
    Jonasson, Mikael
    Closing words!2009In: Guiding and guided tours / [ed] Adolfsson, P., Dobers, P. & Jonasson, M., Göteborg: BAS Publishers , 2009, p. 215-217Chapter in book (Other academic)
  • 153. Adolfsson, Petra
    et al.
    Dobers, PeterMälardalen University, School of Business, Society and Engineering.Jonasson, Mikael
    Guiding and guided tours2009Collection (editor) (Other academic)
  • 154. Adolfsson, Petra
    et al.
    Dobers, Peter
    Mälardalen University, School of Business, Society and Engineering.
    Jonasson, Mikael
    Introduction – Guiding and guided tours2009In: Guiding and guided tours / [ed] Adolfsson, P., Dobers, P. & Jonasson, M., Göteborg: BAS Publishers , 2009, p. 15-28Chapter in book (Other academic)
  • 155.
    Afifi, S.
    et al.
    Auckland University of Technology, Auckland, New Zealand.
    Gholamhosseini, H.
    Auckland University of Technology, Auckland, New Zealand.
    Sinha, R.
    Auckland University of Technology, Auckland, New Zealand.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    A Novel Medical Device for Early Detection of Melanoma2019In: Studies in Health Technology and Informatics, ISSN 0926-9630, E-ISSN 1879-8365, Vol. 261, p. 122-127Article in journal (Refereed)
    Abstract [en]

    Melanoma is the deadliest form of skin cancer. Early detection of melanoma is vital, as it helps in decreasing the death rate as well as treatment costs. Dermatologists are using image-based diagnostic tools to assist them in decision-making and detecting melanoma at an early stage. We aim to develop a novel handheld medical scanning device dedicated to early detection of melanoma at the primary healthcare with low cost and high performance. However, developing this particular device is very challenging due to the complicated computations required by the embedded diagnosis system. In this paper, we propose a hardware-friendly design for implementing an embedded system by exploiting the recent hardware advances in reconfigurable computing. The developed embedded system achieved optimized implementation results for the hardware resource utilization, power consumption, detection speed and processing time with high classification accuracy rate using real data for melanoma detection. Consequently, the proposed embedded diagnosis system meets the critical embedded systems constraints, which is capable for integration towards a cost- and energy-efficient medical device for early detection of melanoma.

  • 156.
    Afonso Olsson Ringby, Nancy
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Fredriksson, Malin
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wictorson, Ulrika
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Etablering och internationalisering av en produkt på konfektyrmarknaden2009Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Problem: Då konfektyrmarknaden är välutbredd krävs det att företag inom den branschen noga överväger hur de vill etablera sin produkt på en ny marknad och hur de ska gå tillväga vid en internationalisering. Det finns flera olika tillvägagångssätt vid etablering och internationalisering. Uppsatsen beskriver dock företags etablerings- och internationaliseringsprocess utifrån utvalda internationaliserings- och etableringsmodeller samt ett antal begrepp.

    Syfte: Uppsatsens syfte är att beskriva hur företaget Manner har gått tillväga med sin etablering i Sverige med hjälp av erfarenheter från etableringen på hemmamarknaden och distributörens erfarenhet på den svenska marknaden.

    Metod: Studien är uppbyggd med två huvudrubriker som är etablering och internationalisering. Data som har använts är primärdata i form av intervjuer som var semistrukturerade och utfördes både i form av personliga intervjuer, mejlintervjuer och telefonintervjuer. Intervjuerna har sedan sammanställts och analyserats utifrån de teorier som valts som den teoretisk referensram.

    Resultat: Resultatet av undersökningen visade att företaget Manner har dragit nytta av sina tidigare erfarenheter från etableringen på hemmamarknaden i Österrike. Det beskrivs även hur de har använt sig av tidigare erfarenheter och hur de påverkats av omgivande faktorer med hjälp av internationaliserings- och etableringsmodeller.

  • 157.
    Afsar, Atahan
    et al.
    Sabanci University, Istanbul.
    Ulubilge, Tunca
    Sabanci University, Istanbul.
    Çürüklü, Baran
    Mälardalen University, School of Innovation, Design and Engineering.
    A biological plausible recurrent model of V1 hypercolumns2011In: BMC neuroscience (Online), ISSN 1471-2202, E-ISSN 1471-2202, Vol. 12(Suppl 1), no P48Article in journal (Refereed)
  • 158.
    Afshar, Sara
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Lock-Based Resource Sharing for Real-Time Multiprocessors2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Embedded systems are widely used in the industry and are typically resource constrained, i.e., resources such as processors, I/O devices, shared buffers or shared memory might be limited in the system. Hence, techniques that can enable an efficient usage of processor bandwidths in such systems are of great importance. Locked-based resource sharing protocols are proposed as a solution to overcome resource limitation by allowing the available resources in the system to be safely shared. In recent years, due to a dramatic enhancement in the functionality of systems, a shift from single-core processors to multi-core processors has become inevitable from an industrial perspective to tackle the raised challenges due to increased system complexity. However, the resource sharing protocols are not fully mature for multi-core processors. The two classical multi-core processor resource sharing protocols, spin-based and suspension-based protocols, although providing mutually exclusive access to resources, can introduce long blocking delays to tasks, which may be unacceptable for many industrial applications. In this thesis we enhance the performance of resource sharing protocols for partitioned scheduling, which is the de-facto scheduling standard for industrial real-time multi-core processor systems such as in AUTOSAR, in terms of timing and memory requirements.

     

    A new scheduling approach uses a resource efficient hybrid approach combining both partitioned and global scheduling where the partitioned scheduling is used to schedule the major number of tasks in the system. In such a scheduling approach applications with critical task sets use partitioned scheduling to achieve higher level of predictability. Then the unused bandwidth on each core that is remained from partitioning is used to schedule less critical task sets using global scheduling to achieve higher system utilization. These scheduling schema however lacks a proper resource sharing protocol since the existing protocols designed for partitioned and global scheduling cannot be directly applied due to the complex hybrid structure of these scheduling frameworks. In this thesis we propose a resource sharing solution for such a complex structure. Further, we provide the blocking bounds incurred to tasks under the proposed protocols and enhance the schedulability analysis, which is an essential requirement for real-time systems, with the provided blocking bounds.

  • 159.
    Afshar, Sara
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Lock-Based Resource Sharing in Real-Time Multiprocessor Platforms2014Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Embedded systems are typically resource constrained, i.e., resources such as processors, I/O devices, shared buffers or shared memory can be limited for tasks in the system. Therefore, techniques that enable an efficient usage of such resources are of great importance.

    In the industry, typically large and complex software systems are divided into smaller parts (applications) where each part is developed independently. Migration towards multiprocessor platforms has become inevitable from an industrial perspective. Due to such migration and to efficient use of system resources, these applications eventually may be integrated on a shared multiprocessor platform. In order to facilitate the integration phase of the applications on a shared platform, the timing and resource requirements of each application can be provided in an interface when the application is developed. The system integrator can benefit from such provided information in the interface of each application to ease the integration process. In this thesis, we have provided the resource and timing requirements of each application in their interfaces for applications that may need several processors to be allocated on when they are developed.

    Although many scheduling techniques have been studied for multiprocessor systems, these techniques are usually based on the assumption that tasks are independent, i.e. do not share resources other than the processors. This assumption is typically not true. In this thesis, we provide an extension to such systems to handle sharing of resources other than processor among tasks. Two traditional approaches exist for multiprocessor systems to schedule tasks on processors. A recent scheduling approach for multiprocessors has combined the two traditional approaches and achieved a hybrid more efficient approach compared to the two previous one. Due to the complex nature of this scheduling approach the conventional approaches for resource sharing could not be used straight forwardly. In this thesis, we have modified resource sharing approaches such that they can be used in such hybrid scheduling systems. A second concern is that enabling resource sharing in the systems can cause unpredictable delays and variations in response time of tasks which can degrade system performance. Therefore, it is of great significance to improve the resource handling techniques to reduce the effect of imposed delays caused by resource sharing in a multiprocessor platform. In this thesis we have proposed alternative techniques for resource handling that can improve system performance for special setups.

  • 160.
    Afshar, Sara
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Resource Sharing under Server-based Multiprocessor SchedulingIn: 33rd IEEE Real-Time Systems Symposium (RTSS'12), Work-in-Progress (WiP) sessionConference paper (Refereed)
    Abstract [en]

    In this paper, we investigate a mechanism for handling resource sharing among tasks under a server-based scheduling technique in multiprocessor platforms, which combines partitioned and global scheduling to benefit a better scheduling method compared to conventional techniques.

  • 161.
    Afshar, Sara
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Bril, R. J.
    Technische Universiteit Eindhoven, Eindhoven, Netherlands .
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Flexible spin-lock model for resource sharing in multiprocessor real-time systems2014In: Proc. IEEE Int. Symp. Ind. Embedded Syst., SIES, 2014, p. 41-51Conference paper (Refereed)
    Abstract [en]

    Various approaches can be utilized upon resource locking for mutually exclusive resource access in multiprocessor platforms. So far two conventional approaches exist for dealing with tasks that are blocked on a global resource in a multi-processor platform. Either the blocked task performs a busy wait, i.e. spins, at the highest priority level until the resource is released, or it is suspended. Although both approaches provide mutually exclusive access to resources, they can introduce long blocking delays to tasks, which may be unacceptable for many industrial applications. In this paper, we propose a general spin-based model for resource sharing in multiprocessor platforms in which the priority of the blocked tasks during spinning can be selected arbitrarily. Moreover, we provide the analysis for two selected spin-lock priorities and we show by means of a general comparison as well as specific examples that these solutions may provide a better performance for higher priority tasks.

  • 162.
    Afshar, Sara
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Bril, Reinder J.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Resource sharing in a hybrid partitioned/global scheduling framework for multiprocessors2015In: IEEE International Conference on Emerging Technologies and Factory Automation, ETFA, 2015Conference paper (Refereed)
    Abstract [en]

    For resource-constrained embedded real-time systems, resource-efficient approaches are very important. Such an approach is presented in this paper, targeting systems where a critical application is partitioned on a multi-core platform and the remaining capacity on each core is provided to a noncritical application using resource reservation techniques. To exploit the potential parallelism of the non-critical application, global scheduling is used for its constituent tasks. Previously, we enabled intra-application resource sharing for such a framework, i.e. each application has its own dedicated set of resources. In this paper, we enable inter-application resource sharing, in particular between the critical application and the non-critical application. This effectively enables resource sharing in a hybrid partitioned/global scheduling framework on multiprocessors. For resource sharing, we use a spin-based synchronization protocol. We derive blocking bounds and extend existing schedulability analysis for such a system.

  • 163.
    Afshar, Sara
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Bril, Reinder J.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. Technische Universiteit Eindhoven, Eindhoven, Netherlands.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Resource Sharing Under Global Scheduling with Partial Processor Bandwidth2015In: 2015 10th IEEE International Symposium on Industrial Embedded Systems, SIES 2015 - Proceedings, 2015, p. 195-206Conference paper (Refereed)
    Abstract [en]

    Resource efficient approaches are of great importance for resource constrained embedded systems. In this paper, we present an approach targeting systems where tasks of a critical application are partitioned on a multi-core platform and by using resource reservation techniques, the remaining bandwidth capacity on each core is utilized for one or a set of non-critical application(s). To provide a resource efficient solution and to exploit the potential parallelism of the extra applications on the multi-core processor, global scheduling is used to schedule the tasks of the non-critical applications. Recently a specific instantiation of such a system has been studied where tasks do not share resources other than the processor. In this paper, we enable semaphore-based resource sharing among tasks within critical and non-critical applications using a suspension-based synchronization protocol. Tasks of non-critical applications have partial access to the processor bandwidth. The paper provides the systems schedulability analysis where blocking due to resource sharing is bounded. Further, we perform experimental evaluations under balanced and unbalanced allocation of tasks of a critical application to cores.

  • 164.
    Afshar, Sara
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    J. Bril, Reinder
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Per Processor Spin-Lock Priority for Partitioned Multiprocessor Real-Time Systems2014Report (Other academic)
    Abstract [en]

    Two traditional approaches exist for a task that is blocked on a global resource; a task either performs a non-preemptive busy wait, i.e., spins, or suspends and releases the processor. Previously, we have shown that both approaches can be viewed as spinning either at the highest priority HP or at the lowest priority on the processor LP, respectively. Based on this view, previously we have generalized a task's blocking behavioral model, as spinning at any arbitrary priority level. In this paper, we focus on a particular class of spin-lock protocols from the introduced flexible spin-lock model where spinning is performed at a priority equal to or higher than the highest local ceiling of the global resources accessed on a processor referred to as CP spin-lock approach. In this paper, we assume that all tasks of a specific processor are spinning on the same priority level. Given this class and assumption, we show that there exists a spin-lock protocol in this range that dominates the classic spin-lock protocol which tasks spin on highest priority level (HP). However we show that this new approach is incomparable with the CP spin-lock approach. Moreover, we show that there may exist an intermediate spin-lock approach between the priority used by CP spin-lock approach and the new introduced spin-lock approach that can make a task set schedulable when those two cannot. We provide an extensive evaluation results comparing the HP, CP and the new proposed approach.

  • 165.
    Afshar, Sara
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    J. Bril, Reinder
    Technische Universiteit Eindhoven, Eindhoven, The Netherlands.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Per Processor Spin-Lock Priority for Partitioned Multiprocessor Real-Time Systems2017In: Leibniz Transactions on Embedded Systems, ISSN 2199-2002, no 2Article in journal (Other academic)
    Abstract [en]

    Two traditional approaches exist for a task that is blocked on a global resource; a task either performs a non-preemptive busy wait, i.e., spins, or suspends and releases the processor. Previously, we have shown that both approaches can be viewed as spinning either at the highest priority HP or at the lowest priority on the processor LP, respectively. Based on this view, previously we have generalized a task's blocking behavioral model, as spinning at any arbitrary priority level. In this paper, we focus on a particular class of spin-lock protocols from the introduced flexible spin-lock model where spinning is performed at a priority equal to or higher than the highest local ceiling of the global resources accessed on a processor referred to as CP spin-lock approach. In this paper, we assume that all tasks of a specific processor are spinning on the same priority level. Given this class and assumption, we show that there exists a spin-lock protocol in this range that dominates the classic spin-lock protocol which tasks spin on highest priority level (HP). However we show that this new approach is incomparable with the CP spin-lock approach. Moreover, we show that there may exist an intermediate spin-lock approach between the priority used by CP spin-lock approach and the new introduced spin-lock approach that can make a task set schedulable when those two cannot. We provide an extensive evaluation results comparing the HP, CP and the new proposed approach.

  • 166.
    Afshar, Sara
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Integrating independently developed real-time applications on a shared multi-core architecture2013In: ACM SIGBED Review, v. 10, n. 3, 2013, p. 49-56Conference paper (Refereed)
    Abstract [en]

    The shift towards multi-core platforms has become inevitable from an industry perspective, therefore proper techniques are needed to deal with challenges related to this migration from single core architectures to a multi-core architecture. One of the main concerns for the system developers in this context is the migration of legacy real-time systems to multi-core architectures. To address this concern and to simplify migration, independently developed subsystems are abstracted with an interface, such that when working with multiple independently-developed subsystems to be integrated on a shared platform, one does not need to be aware of information or policies used in other subsystems in order to determine subsystem-level schedulability. Instead schedulability can be checked through their interfaces at the time of integration on a shared multi-core architecture. In this paper we propose a solution for the case where some of the independently-developed subsystems are distributed over more than one processor and we propose an approach to generate interfaces of subsystems that may share mutually exclusive resources.

  • 167.
    Afshar, Sara
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Semi-partitioning under a Blocking-Aware Task Allocation2015In: Proceedings - Real-Time Systems Symposium, 2015, p. 379-379Conference paper (Refereed)
    Abstract [en]

    Semi-partitioned scheduling is a resource efficient scheduling approach compared to the conventional multiprocessor scheduling approaches in terms of system utilization and migration overhead. Semi-partitioned scheduling can better utilize processor bandwidth compared to the partitioned scheduling while introducing less overhead compared to the global scheduling. Various techniques have been proposed to schedule tasks in a semi-partitioned environment, however, they have used blockingagnostic allocation mechanisms in presence of resource sharing protocols. Since, the allocation mechanism can highly affect the system schedulability, in this paper we provide a blocking-aware allocation mechanism for semi-partitioned scheduling framework under a suspension-based resource sharing protocol. We have applied new heuristics for sorting the tasks in the algorithm that shows improvements upon system schedulability. Finally, we present our preliminary results.

  • 168.
    Afshar, Sara
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Khalilzad, Nima
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Bril, Reinder J.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. Universiteit Eindhoven, Eindhoven, Netherlands.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Intra-component Resource Sharing on a Virtual Multiprocessor Platform2016In: ACM SIGBED Review: Special Issue on 8th International Workshop on Compositional Theory and Technology for Real-Time Embedded Systems, 2016, p. 31-32Conference paper (Refereed)
    Abstract [en]

    Component-based software development facilitates the development process of large and complex software systems. By the advent of multiprocessors, the independently developed components can be integrated on a multi-core platform to achieve an efficient use of system hardware and a decrease in system power consumption and costs. In this paper, we consider a virtual multiprocessor platform where each component can be dynamically allocated to any set of processors of the platform with a maximum concurrency level. Global-EDF is used for intra-component scheduling. The existing analysis for such systems have assumed that tasks are independent. In this paper, we enable intra-component resource sharing for this platform. We investigate using a spin-based resource sharing protocol with the accompanying analysis that extends the existing analysis for independent tasks. We briefly illustrate and evaluate our initial results with an example.

  • 169.
    Afshar, Sara
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Moghaddami Khalilzad, Nima
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Nemati, Farhang
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Resource Sharing among Prioritized Real-Time Applications on Multiprocessors2015In: ACM SIGBED Review - Special Issue on the 6th International Workshop on Compositional Theory and Technology for Real-Time Embedded Systems Homepage archiveVolume 12 Issue 1, 2015, p. 46-55Conference paper (Refereed)
    Abstract [en]

    In this paper, we propose a new protocol for handling resource sharing among prioritized real-time applications composed on a multiprocessor platform. We propose an optimal priority assignment algorithm which assigns unique priorities to the applications based on information in their interfaces. We have performed experimental evaluations to compare the proposed protocol (called MSOS-Priority) to the current state of the art locking protocols under multiprocessor partitioned scheduling, i.e., MPCP, MSRP, FMLP, MSOS, and OMLP. The valuations show that MSOS-Priority mostly performs significantly better than alternative approaches.

  • 170.
    Afshar, Sara
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Nemati, Farhang
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Resource Sharing under Multiprocessor Semi-Partitioned Scheduling2012In: 18th IEEE International Conference on Embedded and Real-Time Computing Systems and Applications (RTCSA'12), 2012, p. 290-299Conference paper (Refereed)
    Abstract [en]

    Semi-partitioned scheduling has become the subject of recent interest for multiprocessors due to better utilization results, compared to conventional global and partitioned scheduling algorithms. Under semi-partitioned scheduling, a major group of tasks are assigned to fixed processors while a low number of tasks are allocated to more than one processor. Various task assigning techniques have recently been proposed in a semi-partitioned environment. However, a synchronization mechanism for resource sharing among tasks in semi-partitioned scheduling has not yet been investigated. In this paper we propose and evaluate two methods for handling resource sharing under semi-partitioned scheduling in multiprocessor platforms. The main challenge addressed in this paper is to serve the resource requests of tasks that are assigned to different processors.

  • 171.
    Afshar, Sara
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Nemati, Farhang
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Towards Resource Sharing under Multiprocessor Semi-Partitioned Scheduling2012In: 7th IEEE International Symposium on Industrial Embedded Systems (SIES'12): Conference Proceedings, 2012, p. 315-318Conference paper (Refereed)
    Abstract [en]

    Semi-partitioned scheduling has been the subject of recent interest, compared with conventional global and partitioned scheduling algorithms for multiprocessors, due to better utilization results. In semi-partitioned scheduling most tasks are assigned to fixed processors while a low number of tasks are split up and allocated to different processors. Various techniques have recently been proposed to assign tasks in a semi-partitioned environment. However, an appropriate resource sharing mechanism for handling the resource requests between tasks in semi-partitioned scheduling has not yet been investigated. In this paper we propose two methods for handling resource sharing under semi-partitioned scheduling in multiprocessor platforms. The main challenge is to handle the resource requests of tasks that are split over multiple processors.

  • 172.
    Afshar, Sara Zargari
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Real-time and offline evaluation of myoelectric pattern recognition for upper limb prosthesis controlManuscript (preprint) (Other academic)
  • 173.
    Afshar, Sara Zargari
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    J. Bril, Reinder
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. Technische Universiteit Eindhoven, Eindhoven, Netherlands.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    An optimal spin-lock priority assignment algorithm for real-time multi-core systems2017In: The 23th IEEE International Conference on Embedded and Real-Time Computing Systems and Applications RTCSA'17, 2017, article id 8046310Conference paper (Refereed)
    Abstract [en]

    Support for exclusive access to shared (global) resources is instrumental in the context of embedded real-time multi-core systems, and mechanisms for achieving such access must be deterministic and efficient. There exist two traditional approaches for multiprocessors when a task requests a global resource that is locked by a task on a remote core: a spin-based approach, i.e. non-preemptive busy waiting for the resource to become available, and a suspension-based approach, i.e. the task relinquishes the processor. A suspension-based approach can be viewed as a spin-based approach where the lowest priority on a core is used during spinning, similar to a non-preemptive spin-based approach where the highest priority on a core is used. By taking such a view, we previously provided a general model for spinning, where any arbitrary priority can be used for spinning, i.e. from the lowest to the highest priority on a core. Targeting partitioned fixed-priority preemptive scheduled multiprocessors and spin-based approaches that use a fixed priority for spinning per core for all tasks, we aim at increasing the schedulability of multiprocessor systems by using the spin-lock priority per core as parameter. In this paper, we present (i) a generalization of the traditional worst-case response-time analysis for non-preemptive spin-based approaches addressing an arbitrary but fixed spin-lock priority per core, (ii) an optimal spin-lock priority assignment (OSPA) algorithm per core, i.e. an algorithm that will find a fixed spin-lock priority per core that will make the system schedulable, whenever such an assignment exists and, (iii) comparative evaluations of the OSPA algorithm with the spin-based and suspension-based approaches where OSPA showed up to 38% improvement compared to both approaches.

  • 174.
    Afshari, Houtan
    Mälardalen University, School of Innovation, Design and Engineering.
    Finding optimum batch sizes for a high mix, low volume surface mount technology line2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 175.
    Afsharmazayejani, R.
    et al.
    Shahid Bahonar University of Kerman, Kerman, Iran.
    Yazdanpanah, F.
    Vali-e-Asr University, Rafsanjan, Iran.
    Rezaei, A.
    Northwestern University, Evanston, United States.
    Alaei, M.
    Vali-e-Asr University, Rafsanjan, Iran.
    Daneshtalab, Masoud
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    HoneyWiN: Novel honeycomb-based wireless NoC architecture in many-core era2018In: Lecture Notes in Computer Science, ISSN 0302-9743, E-ISSN 1611-3349, Vol. 10824 LNCS, p. 304-316Article in journal (Refereed)
    Abstract [en]

    Although NoC-based systems with many cores are commercially available, their multi-hop nature has become a bottleneck on scaling performance and energy consumption parameters. Alternatively, hybrid wireless NoC provides a postern by exploiting single-hop express links for long-distance communications. Also, there is a common wisdom that grid-like mesh is the most stable topology in conventional designs. That is why almost all of the emerging architectures had been relying on this topology as well. In this paper, first we challenge the efficiency of the grid-like mesh in emerging systems. Then, we propose HoneyWiN, a hybrid reconfigurable wireless NoC architecture that relies on the honeycomb topology. The simulation results show that on average HoneyWiN saves 17% of energy consumption while increases the network throughput by 10% compared to its wireless mesh counterpart. 

  • 176.
    Afzal, Wasif
    Mälardalen University, School of Innovation, Design and Engineering. Embedded Systems.
    Search-based approaches to software fault prediction and software testing2009Licentiate thesis, monograph (Other academic)
    Abstract [en]

    Software verification and validation activities are essential for software quality but also constitute a large part of software development costs. Therefore efficient and cost effective software verification and validation activities are both a priority and a necessity considering the pressure to decrease time-to-market and intense competition faced by many, if not all, companies today. It is then perhaps not unexpected that decisions related to software quality, when to stop testing, testing schedule and testing resource allocation needs to be as accurate as possible. This thesis investigates the application of search-based techniques within two activities of software verification and validation: Software fault prediction and software testing for non-functional system properties. Software fault prediction modeling can provide support for making important decisions as outlined above. In this thesis we empirically evaluate symbolic regression using genetic programming (a search-based technique) as a potential method for software fault predictions. Using data sets from both industrial and open-source software, the strengths and weaknesses of applying symbolic regression in genetic programming are evaluated against competitive techniques. In addition to software fault prediction this thesis also consolidates available research into predictive modeling of other attributes by applying symbolic regression in genetic programming, thus presenting a broader perspective. As an extension to the application of search-based techniques within software verification and validation this thesis further investigates the extent of application of search-based techniques for testing non-functional system properties. Based on the research findings in this thesis it can be concluded that applying symbolic regression in genetic programming may be a viable technique for software fault prediction. We additionally seek literature evidence where other search-based techniques are applied for testing of non-functional system properties, hence contributing towards the growing application of search-based techniques in diverse activities within software verification and validation.

  • 177. Afzal, Wasif
    Search-based prediction of software quality: Evaluations and comparisons2011Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Software verification and validation (V&V) activities are critical for achieving software quality; however, these activities also constitute a large part of the costs when developing software. Therefore efficient and effective software V&V activities are both a priority and a necessity considering the pressure to decrease time-to-market and the intense competition faced by many, if not all, companies today. It is then perhaps not unexpected that decisions that affects software quality, e.g., how to allocate testing resources, develop testing schedules and to decide when to stop testing, needs to be as stable and accurate as possible. The objective of this thesis is to investigate how search-based techniques can support decision-making and help control variation in software V&V activities, thereby indirectly improving software quality. Several themes in providing this support are investigated: predicting reliability of future software versions based on fault history; fault prediction to improve test phase efficiency; assignment of resources to fixing faults; and distinguishing fault-prone software modules from non-faulty ones. A common element in these investigations is the use of search-based techniques, often also called metaheuristic techniques, for supporting the V&V decision-making processes. Search-based techniques are promising since, as many problems in real world, software V&V can be formulated as optimization problems where near optimal solutions are often good enough. Moreover, these techniques are general optimization solutions that can potentially be applied across a larger variety of decision-making situations than other existing alternatives. Apart from presenting the current state of the art, in the form of a systematic literature review, and doing comparative evaluations of a variety of metaheuristic techniques on large-scale projects (both industrial and open-source), this thesis also presents methodological investigations using search-based techniques that are relevant to the task of software quality measurement and prediction. The results of applying search-based techniques in large-scale projects, while investigating a variety of research themes, show that they consistently give competitive results in comparison with existing techniques. Based on the research findings, we conclude that search-based techniques are viable techniques to use in supporting the decision-making processes within software V&V activities. The accuracy and consistency of these techniques make them important tools when developing future decision support for effective management of software V&V activities.

  • 178.
    Afzal, Wasif
    Blekinge Institute of Technology.
    Using faults-slip-through metric as a predictor of fault-proneness2010In: Proceedings - Asia-Pacific Software Engineering Conference, APSEC, 2010, p. 412-422Conference paper (Refereed)
    Abstract [en]

    Background: The majority of software faults are present in small number of modules, therefore accurate prediction of fault-prone modules helps improve software quality by focusing testing efforts on a subset of modules. Aims: This paper evaluates the use of the faults-slip-through (FST) metric as a potential predictor of fault-prone modules. Rather than predicting the fault-prone modules for the complete test phase, the prediction is done at the speci?c test levels of integration and system test. Method: We applied eight classi?cation techniques, to the task of identifying faultprone modules, representing a variety of approaches, including a standard statistical technique for classi?cation (logistic regression), tree-structured classi?ers (C4.5 and random forests), a Bayesian technique (Naïve Bayes), machine-learning techniques (support vector machines and back-propagation arti?cial neural networks) and search-based techniques (genetic programming and arti?cial immune recognition systems) on FST data collected from two large industrial projects from the telecommunication domain. Results: Using area under the receiver operating characteristic (ROC) curve and the location of (PF, PD) pairs in the ROC space, the faults-slip-through metric showed impressive results with the majority of the techniques for predicting fault-prone modules at both integration and system test levels. There were, however, no statistically signi?cant differences between the performance of different techniques based on AUC, even though certain techniques were more consistent in the classi?cation performance at the two test levels. Conclusions: We can conclude that the faults-slip-through metric is a potentially strong predictor of fault-proneness at integration and system test levels. The faults-slip-through measurements interact in ways that is conveniently accounted for by majority of the data mining techniques.

  • 179.
    Afzal, Wasif
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. Bahria University, Islamabad, Pakistan.
    Alone, Snehal
    Chalmers University of Technology, Sweden.
    Glocksien, Kerstin
    Chalmers University of Technology, Sweden.
    Torkar, Richard
    Chalmers University of Technology, Sweden.
    Software Test Process Improvement Approaches: A Systematic Literature Review and an Industrial Case Study2016In: Journal of Systems and Software JSS, ISSN 0164-1212, Vol. 111, p. 1-33Article in journal (Refereed)
    Abstract [en]

    Software test process improvement (STPI) approaches are frameworks that guide software development organizations to improve their software testing process. We have identified existing STPI approaches and their characteristics (such as completeness of development, availability of information and assessment instruments, and domain limitations of the approaches) using a systematic literature review (SLR). Furthermore, two selected approaches (TPI NEXT and TMMi) are evaluated with respect to their content and assessment results in industry. As a result of this study, we have identified 18 STPI approaches and their characteristics. A detailed comparison of the content of TPI NEXT and TMMi is done. We found that many of the STPI approaches do not provide sufficient information or the approaches do not include assessment instruments. This makes it difficult to apply many approaches in industry. Greater similarities were found between TPI NEXT and TMMi and fewer differences. We conclude that numerous STPI approaches are available but not all are generally applicable for industry. One major difference between available approaches is their model representation. Even though the applied approaches generally show strong similarities, differences in the assessment results arise due to their different model representations.

  • 180.
    Afzal, Wasif
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Bruneliere, H.
    IMT Atlantique – LS2N (CNRS) – ARMINES, France.
    Di Ruscio, D.
    Università degli Studi dell'Aquila - DISIM | Center of Excellence DEWS, Italy.
    Sadovykh, A.
    Softeam, France.
    Mazzini, S.
    Intecs, Italy.
    Cariou, E.
    Université de Pau et des Pays de l'Adour, LIUPPA, France.
    Truscan, D.
    Åbo Akademi University, Finland.
    Cabot, J.
    ICREA, Spain.
    Gómez, A.
    Internet Interdisciplinary Institute (IN3), Universitat Oberta de Catalunya (UOC), Spain.
    Gorroñogoitia, J.
    ATOS, Spain.
    Pomante, L.
    Università degli Studi dell'Aquila - DISIM | Center of Excellence DEWS, Italy.
    Smrz, P.
    Brno University of Technology, Czech Republic.
    The MegaM@Rt2 ECSEL project: MegaModelling at Runtime – Scalable model-based framework for continuous development and runtime validation of complex systems2018In: Microprocessors and microsystems, ISSN 0141-9331, E-ISSN 1872-9436, Vol. 61, p. 86-95Article in journal (Refereed)
    Abstract [en]

    A major challenge for the European electronic industry is to enhance productivity by ensuring quality of development, integration and maintenance while reducing the associated costs. Model-Driven Engineering (MDE) principles and techniques have already shown promising capabilities, but they still need to scale up to support real-world scenarios implied by the full deployment and use of complex electronic components and systems. Moreover, maintaining efficient traceability, integration, and communication between two fundamental system life cycle phases (design time and runtime) is another challenge requiring the scalability of MDE. This paper presents an overview of the ECSEL 1 project entitled “MegaModelling at runtime – Scalable model-based framework for continuous development and runtime validation of complex systems” (MegaM@Rt2), whose aim is to address the above mentioned challenges facing MDE. Driven by both large and small industrial enterprises, with the support of research partners and technology providers, MegaM@Rt2 aims to deliver a framework of tools and methods for: 1) system engineering/design and continuous development, 2) related runtime analysis and 3) global models and traceability management. Diverse industrial use cases (covering strategic domains such as aeronautics, railway, construction and telecommunications) will integrate and demonstrate the validity of the MegaM@Rt2 solution. This paper provides an overview of the MegaM@Rt2 project with respect to its approach, mission, objectives as well as to its implementation details. It further introduces the consortium as well as describes the work packages and few already produced deliverables.

  • 181.
    Afzal, Wasif
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Bruneliere, Hugo
    AtlanMod Team, Inria, France.
    Di Ruscio, Davide
    Univ. of L'Aquila, L'Aquila, Italy.
    Sadovykh, Andrey
    Softeam, France.
    Mazzini, Silvia
    Intecs, Italy.
    Cariou, Eric
    Univ. de Pau et des Pays de l'Adour, Pau, France.
    Truscan, Dragos
    Åbo Akademi Univ., Turku, Finland.
    Cabot, Jordi
    Jordi Cabot ICREA, Barcelona, Spain.
    Field, Daniel
    ATOS, Madrid, Spain.
    Pomante, Luigi
    Univ. of L'Aquila, L'Aquila, Italy.
    Smrz, Pavel
    Brno Univ. of Technol., Brno, Czech Republic.
    The MegaM@Rt2 ECSEL Project: MegaModelling at Runtime — Scalable Model-Based Framework for Continuous Development and Runtime Validation of Complex Systems2017In: The 2017 Euromicro Conference on Digital System Design DSD'17, 2017Conference paper (Refereed)
    Abstract [en]

    A major challenge for the European electronic industry is to enhance productivity while reducing costs and ensuring quality in development, integration and maintenance. Model-Driven Engineering (MDE) principles and techniques have already shown promising capabilities but still need to scale to support real-world scenarios implied by the full deployment and use of complex electronic components and systems. Moreover, maintaining efficient traceability, integration and communication between two fundamental system life-time phases (design time and runtime) is another challenge facing scalability of MDE. This paper presents an overview of the ECSEL project entitled "MegaModelling at runtime -- Scalable model-based framework for continuous development and runtime validation of complex systems" (MegaM@Rt2), whose aim is to address the above mentioned challenges facing MDE. Driven by both large and small industrial enterprises, with the support of research partners and technology providers, MegaM@Rt2 aims to deliver a framework of tools and methods for: 1) system engineering/design & continuous development, 2) related runtime analysis and 3) global model & traceability management, respectively. The diverse industrial use cases (covering domains such as aeronautics, railway, construction and telecommunications) will integrate and apply such a framework that shall demonstrate the validation of the MegaM@Rt2 solution.

  • 182.
    Afzal, Wasif
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Caporuscio, M.
    Linnaeus University, Sweden.
    Conboy, H.
    University of Massachusetts Amherst, MA, United States.
    Di Marco, A.
    University of l'Aquila, Italy.
    Duchien, D. L.
    University of Lille, France.
    Pérez, D.
    University of British Columbia, Canada.
    Seceleanu, C.
    Kyushu University, Japan.
    Shahbazian, A.
    University of California, Berkeley, CA, United States.
    Spalazzese, R.
    Microsoft, WA, United States.
    Tivoli, M.
    Florida State University, FL, United States.
    Vasilescu, B.
    University College Dublin and Lero, Ireland.
    Washizaki, H
    Mälardalen University.
    Weyns, D.
    University of Southern California, CA, United States.
    Pasquale, L.
    Malmö University, Sweden.
    Nistor, A.
    Malmö University, Sweden.
    Muşlu, K.
    Waseda University, Japan.
    Kamei, Y.
    Waseda University, Japan.
    Hanam, Q.
    Carnegie Mellon University, PA, United States.
    Ying, A. T. T.
    Katholieke Universiteit Leuven, Belgium.
    Program committee for icse 2018 posters track2018In: Proceedings / International Conference of Software Engineering, ISSN 0270-5257, E-ISSN 1558-1225, Vol. Part F137351Article in journal (Refereed)
  • 183.
    Afzal, Wasif
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Ghazi, Nauman
    Blekinge Institute of Technolog.
    Itkonen, Juha
    Aalto University, Espoo, Finland.
    Torkar, Richard
    Chalmers University of Technology.
    Andrews, Anneliese
    University of Denver, USA.
    Bhatti, Khurram
    Blekinge Institute of Technolog.
    An experiment on the effectiveness and efficiency of exploratory testing2015In: Journal of Empirical Software Engineering, ISSN 1382-3256, E-ISSN 1573-7616, Vol. 20, no 3, p. 844-878Article in journal (Refereed)
    Abstract [en]

    The exploratory testing (ET) approach is commonly applied in industry, but lacks scientific research. The scientific community needs quantitative results on the performance of ET taken from realistic experimental settings. The objective of this paper is to quantify the effectiveness and efficiency of ET vs. testing with documented test cases (test case based testing, TCT). We performed four controlled experiments where a total of 24 practitioners and 46 students performed manual functional testing using ET and TCT. We measured the number of identified defects in the 90-minute testing sessions, the detection difficulty, severity and types of the detected defects, and the number of false defect reports. The results show that ET found a significantly greater number of defects. ET also found significantly more defects of varying levels of difficulty, types and severity levels. However, the two testing approaches did not differ significantly in terms of the number of false defect reports submitted. We conclude that ET was more efficient than TCT in our experiment. ET was also more effective than TCT when detection difficulty, type of defects and severity levels are considered. The two approaches are comparable when it comes to the number of false defect reports submitted.

  • 184.
    Afzal, Wasif
    et al.
    Mälardalen University, School of Innovation, Design and Engineering. Blekinge Institute of Technology.
    Torkar, Richard
    Blekinge Institute of Technology.
    A comparative evaluation of using genetic programming for predicting fault count data2008In: Proceedings - The 3rd International Conference on Software Engineering Advances, ICSEA 2008, Includes ENTISY 2008: International Workshop on Enterprise Information Systems, 2008, p. 407-414Conference paper (Refereed)
    Abstract [en]

    There have been a number of software reliability growth models (SRGMs) proposed in literature. Due to several reasons, such as violation of models’ assumptions and complexity of models, the practitioners face difficulties in knowing which models to apply in practice. This paper presents a comparative evaluation of traditional models and use of genetic programming (GP) for modeling software reliability growth based on weekly fault count data of three different industrial projects. The motivation of using a GP approach is its ability to evolve a model based entirely on prior data without the need of making underlying assumptions. The results show the strengths of using GP for predicting fault count data.

  • 185.
    Afzal, Wasif
    et al.
    Blekinge Institute of Technology.
    Torkar, Richard
    Blekinge Institute of Technology.
    Incorporating metrics in an organizational test strategy2008In: International Conference on Software Testing, Verification and Validation: Proceedings of the International Software Testing Standard Workshop, Collocated with 1st International Conference on Software Testing, Verification and Validation, 2008, p. 304-315Conference paper (Refereed)
    Abstract [en]

    An organizational level test strategy needs to incorporate metrics to make the testing activities visible and available to process improvements. The majority of testing measurements that are done are based on faults found in the test execution phase. In contrast, this paper investigates metrics to support software test planning and test design processes. We have assembled metrics in these two process types to support management in carrying out evidence-based test process improvements and to incorporate suitable metrics as part of an organization level test strategy. The study is composed of two steps. The first step creates a relevant context by analyzing key phases in the software testing lifecycle, while the second step identifies the attributes of software test planning and test design processes along with metric(s) support for each of the identified attributes.

  • 186.
    Afzal, Wasif
    et al.
    Blekinge Institute of Technology.
    Torkar, Richard
    Blekinge Institute of Technology.
    Lessons from applying experimentation in software engineering predictive modeling2008In: Proceedings of The 2nd International workshop on Software Productivity Analysis and Cost Estimation (SPACE'08), Collocated with 15th Asia-Pacific Software Engineering Conference, Beijing, China, 2008Conference paper (Refereed)
    Abstract [en]

    Within software engineering prediction systems, experiments are undertaken primarily to investigate relationships and to measure/compare models’ accuracy. This paper discusses our experience and presents useful lessons/guidelines in experimenting with software engineering prediction systems. For this purpose, we use a typical software engineering experimentation process as a baseline. We found that the typical experimentation process in software engineering is supportive in developing prediction systems and have highlighted issues more central to the domain of software engineering prediction systems.

  • 187.
    Afzal, Wasif
    et al.
    Blekinge Inst Technol.
    Torkar, Richard
    Blekinge Inst Technol.
    On the application of genetic programming for software engineering predictive modeling: A systematic review2011In: Expert systems with applications, ISSN 0957-4174, E-ISSN 1873-6793, Vol. 38, no 9, p. 11984-11997Article in journal (Refereed)
    Abstract [en]

    The objective of this paper is to investigate the evidence for symbolic regression using genetic programming (GP) being an effective method for prediction and estimation in software engineering, when compared with regression/machine learning models and other comparison groups (including comparisons 20 with different improvements over the standard GP algorithm). We performed a systematic review of literature that compared genetic programming models with comparative techniques based on different 22 independent project variables. A total of 23 primary studies were obtained after searching different information sources in the time span 1995–2008. The results of the review show that symbolic regression using genetic programming has been applied in three domains within software engineering predictive modeling: (i) Software quality classification (eight primary studies). (ii) Software cost/effort/size estimation (seven primary studies). (iii) Software fault prediction/software reliability growth modeling (eight primary studies). While there is evidence in support of using genetic programming for software quality classification, software fault prediction and software reliability growth modeling; the results are inconclusive for software cost/effort/size estimation.

  • 188.
    Afzal, Wasif
    et al.
    Blekinge Institute of Technology, Sweden.
    Torkar, Richard
    Blekinge Institute of Technology, Sweden.
    Suitability of genetic programming for software reliability growth modelling2008In: Proceedings - International Symposium on Computer Science and Its Applications, CSA 2008, 2008, p. 114-117Conference paper (Refereed)
    Abstract [en]

    Genetic programming (GP) has been found to be effective in finding a model that fits the given data points without making any assumptions about the model structure. This makes GP a reasonable choice for software reliability growth modeling. This paper discusses the suitability of using GP for software reliability growth modeling and highlights the mechanisms that enable GP to progressively search for fitter solutions.

  • 189.
    Afzal, Wasif
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. Bahria University, Islamabad, Pakistan .
    Torkar, Richard
    Blekinge Institute of Technology, Karlskrona, Sweden; Chalmers University of Technology, Sweden.
    Towards benchmarking feature subset selection methods for software fault prediction2016In: Computational Intelligence and Quantitative Software Engineering / [ed] Witold Pedrycz, Giancarlo Succi and Alberto Sillitti, Springer-Verlag , 2016, p. 33-58Chapter in book (Other academic)
    Abstract [en]

    Despite the general acceptance that software engineering datasets often contain noisy, irrele- vant or redundant variables, very few benchmark studies of feature subset selection (FSS) methods on real-life data from software projects have been conducted. This paper provides an empirical comparison of state-of-the-art FSS methods: information gain attribute ranking (IG); Relief (RLF); principal com- ponent analysis (PCA); correlation-based feature selection (CFS); consistency-based subset evaluation (CNS); wrapper subset evaluation (WRP); and an evolutionary computation method, genetic program- ming (GP), on five fault prediction datasets from the PROMISE data repository. For all the datasets, the area under the receiver operating characteristic curve—the AUC value averaged over 10-fold cross- validation runs—was calculated for each FSS method-dataset combination before and after FSS. Two diverse learning algorithms, C4.5 and na ??ve Bayes (NB) are used to test the attribute sets given by each FSS method. The results show that although there are no statistically significant differences between the AUC values for the different FSS methods for both C4.5 and NB, a smaller set of FSS methods (IG, RLF, GP) consistently select fewer attributes without degrading classification accuracy. We conclude that in general, FSS is beneficial as it helps improve classification accuracy of NB and C4.5. There is no single best FSS method for all datasets but IG, RLF and GP consistently select fewer attributes without degrading classification accuracy within statistically significant boundaries.

  • 190.
    Afzal, Wasif
    et al.
    Blekinge Institute of Technology.
    Torkar, Richard
    Blekinge Institute of Technology.
    Feldt, Robert
    Blekinge Institute of Technology.
    A systematic mapping study on non-functional search-based software testing2008In: 20th International Conference on Software Engineering and Knowledge Engineering, 2008Conference paper (Refereed)
    Abstract [en]

    Automated software test generation has been applied across the spectrum of test case design methods; this includes white-box (structural), black-box (functional), greybox (combination of structural and functional) and nonfunctional testing. In this paper, we undertake a systematic mapping study to present a broad review of primary studies on the application of search-based optimization techniques to non-functional testing. The motivation is to identify the evidence available on the topic and to identify gaps in the application of search-based optimization techniques to different types of non-functional testing. The study is based on a comprehensive set of 35 papers obtained after using a multi-stage selection criteria and are published in workshops, conferences and journals in the time span 1996–2007. We conclude that the search-based software testing community needs to do more and broader studies on nonfunctional search-based software testing (NFSBST) and the results from our systematic map can help direct such efforts.

  • 191.
    Afzal, Wasif
    et al.
    Blekinge Institute of Technology.
    Torkar, Richard
    Blekinge Institute of Technology.
    Feldt, Robert
    Blekinge Institute of Technology.
    A systematic review of search-based testing for non-functional system properties2009In: Information and Software Technology, ISSN 0950-5849, E-ISSN 1873-6025, Vol. 51, no 6, p. 957-976Article, review/survey (Refereed)
    Abstract [en]

    Search-based software testing is the application of metaheuristic search techniques to generate software tests. The test adequacy criterion is transformed into a fitness function and a set of solutions in the search space are evaluated with respect to the fitness function using a metaheuristic search technique. The application of metaheuristic search techniques for testing is promising due to the fact that exhaustive testing is infeasible considering the size and complexity of software under test. Search-based software testing has been applied across the spectrum of test case design methods; this includes white-box (structural), black-box (functional) and grey-box (combination of structural and functional) testing. In addition, metaheuristic search techniques have also been applied to test non-functional properties. The overall objective of undertaking this systematic review is to examine existing work into non-functional search-based software testing (NFSBST). We are interested in types of non-functional testing targeted using metaheuristic search techniques, different fitness functions used in different types of search-based non-functional testing and challenges in the application of these techniques. The systematic review is based on a comprehensive set of 35 articles obtained after a multi-stage selection process and have been published in the time span 1996–2007. The results of the review show that metaheuristic search techniques have been applied for non-functional testing of execution time, quality of service, security, usability and safety. A variety of metaheuristic search techniques are found to be applicable for non-functional testing including simulated annealing, tabu search, genetic algorithms, ant colony methods, grammatical evolution, genetic programming (and its variants including linear genetic programming) and swarm intelligence methods. The review reports on different fitness functions used to guide the search for each of the categories of execution time, safety, usability, quality of service and security; along with a discussion of possible challenges in the application of metaheuristic search techniques.

  • 192.
    Afzal, Wasif
    et al.
    Blekinge Institute of Technolog.
    Torkar, Richard
    Blekinge Institute of Technolog.
    Feldt, Robert
    Blekinge Institute of Technology.
    Prediction of fault count data using genetic programming2008In: IEEE INMIC 2008: 12th IEEE International Multitopic Conference - Conference Proceedings, 2008, p. 349-356Conference paper (Refereed)
    Abstract [en]

    Software reliability growth modeling helps in deciding project release time and managing project resources. A large number of such models have been presented in the past. Due to the existence of many models, the models’ inherent complexity, and their accompanying assumptions; the selection of suitable models becomes a challenging task. This paper presents empirical results of using genetic programming (GP) for modeling software reliability growth based on weekly fault count data of three different industrial projects. The goodness of ?t (adaptability) and predictive accuracy of the evolved model is measured using ?ve different measures in an attempt to present a fair evaluation. The results show that the GP evolved model has statistically signi?cant goodness of ?t and predictive accuracy

  • 193.
    Afzal, Wasif
    et al.
    Bahria Univ, Islamabad, Pakistan.
    Torkar, Richard
    Chalmers University of Technology and the University of Gothenburg.
    Feldt, Robert
    Blekinge Institute of Technology.
    Resampling methods in software quality classification2012In: International journal of software engineering and knowledge engineering, ISSN 0218-1940, Vol. 22, no 2, p. 203-223Article in journal (Refereed)
    Abstract [en]

    In the presence of a number of algorithms for classification and prediction in software engineering, there is a need to have a systematic way of assessing their performances. The performance assessment is typically done by some form of partitioning or resampling of the original data to alleviate biased estimation. For predictive and classification studies in software engineering, there is a lack of a definitive advice on the most appropriate resampling method to use. This is seen as one of the contributing factors for not being able to draw general conclusions on what modeling technique or set of predictor variables are the most appropriate. Furthermore, the use of a variety of resampling methods make it impossible to perform any formal meta analysis of the primary study results. Therefore, it is desirable to examine the influence of various resampling methods and to quantify possible differences. Objective and method: This study empirically compares five common resampling methods (hold-out validation, repeated random sub-sampling, 10-fold cross-validation, leave-one-out cross-validation and nonparametric bootstrapping) using 8 publicly available data sets with genetic programming (GP) and multiple linear regression (MLR) as software quality classification approaches. Location of (PF, PD) pairs in the ROC (receiver operating characteristics) space and area under an ROC curve (AUC) are used as accuracy indicators. Results: The results show that in terms of the location of (PF, PD) pairs in the ROC space, bootstrapping results are in the preferred region for 3 of the 8 data sets for GP and for 4 of the 8 data sets for MLR. Based on the AUC measure, there are no significant differences between the different resampling methods using GP and MLR. Conclusion: There can be certain data set properties responsible for insignificant differences between the resampling methods based on AUC. These include imbalanced data sets, insignificant predictor variables and high-dimensional data sets. With the current selection of data sets and classification techniques, bootstrapping is a preferred method based on the location of (PF, PD) pair data in the ROC space. Hold-out validation is not a good choice for comparatively smaller data sets, where leave-one-out cross-validation (LOOCV) performs better. For comparatively larger data sets, 10-fold cross-validation performs better than LOOCV.

  • 194.
    Afzal, Wasif
    et al.
    Blekinge Institute of Technology.
    Torkar, Richard
    Blekinge Institute of Technology.
    Feldt, Robert
    Blekinge Institute of Technology.
    Search-based prediction of fault count data2009In: Proceedings - 1st International Symposium on Search Based Software Engineering, SSBSE 2009, 2009, p. 35-38Conference paper (Refereed)
    Abstract [en]

    Symbolic regression, an application domain of genetic programming (GP), aims to find a function whose output has some desired property, like matching target values of a particular data set. While typical regression involves finding the coefficients of a pre-defined function,symbolic regression finds a general function, with coefficients,fitting the given set of data points. The conceptsof symbolic regression using genetic programming can be used to evolve a model for fault countpredictions.Such a model has the advantages that the evolution is not dependent on a particular structure of the model and is also independent of any assumptions, which are common in traditional time-domain parametric software reliability growth models. This research aims at applying experiments targeting fault predictionsusing genetic programming and comparing the results with traditional approaches to compare efficiency gains

  • 195.
    Afzal, Wasif
    et al.
    Blekinge Institute of Technology.
    Torkar, Richard
    Blekinge Institute of Technology.
    Feldt, Robert
    Blekinge Institute of Technology.
    Gorschek, Tony
    Blekinge Institute of Technology.
    Genetic programming for cross-release fault count predictions in large and complex software projects2009In: Evolutionary Computation and Optimization Algorithms in Software Engineering / [ed] Monica Chis, IGI Global, 2009Chapter in book (Other academic)
    Abstract [en]

    Software fault prediction can play an important role in ensuring software quality through efficient resource allocation. This could, in turn, reduce the potentially high consequential costs due to faults. Predicting faults might be even more important with the emergence of short-timed and multiple software releases aimed at quick delivery of functionality. Previous research in software fault prediction has indicated that there is a need i) to improve the validity of results by having comparisons among number of data sets from a variety of software, ii) to use appropriate model evaluation measures and iii) to use statistical testing procedures. Moreover, cross-release prediction of faults has not yet achieved sufficient attention in the literature. In an attempt to address these concerns, this paper compares the quantitative and qualitative attributes of 7 traditional and machine-learning techniques for modeling the cross-release prediction of fault count data. The comparison is done using extensive data sets gathered from a total of 7 multi release open-source and industrial software projects. These software projects together have several years of development and are from diverse application areas, ranging from a web browser to a robotic controller software. Our quantitative analysis suggests that genetic programming (GP) tends to have better consistency in terms of goodness of fit and accuracy across majority of data sets. It also has comparatively less model bias. Qualitatively, ease of configuration and complexity are less strong points for GP even though it shows generality and gives transparent models. Artificial neural networks did not perform as well as expected while linear regression gave average predictions in terms of goodness of fit and accuracy. Support vector machine regression and traditional software reliability growth models performed below average on most of the quantitative evaluation criteria while remained on average for most of the qualitative measures.

  • 196.
    Afzal, Wasif
    et al.
    Bahria Univ, Pakistan.
    Torkar, Richard
    Chalmers University of Technology.
    Feldt, Robert
    Blekinge Institute of Technology.
    Gorschek, Tony
    Blekinge Institute of Technology.
    Prediction of faults-slip-through in large software projects: An empirical evaluation2013In: Software quality journal, ISSN 0963-9314, E-ISSN 1573-1367, Vol. 22, no 1, p. 51-86Article in journal (Refereed)
    Abstract [en]

    A large percentage of the cost of rework can be avoided by finding more faults earlier in a software test process. Therefore, determination of which software test phases to focus improvement work on has considerable industrial interest. We evaluate a number of prediction techniques for predicting the number of faults slipping through to unit, function, integration, and system test phases of a large industrial project. The objective is to quantify improvement potential in different test phases by striving toward finding the faults in the right phase. The results show that a range of techniques are found to be useful in predicting the number of faults slipping through to the four test phases; however, the group of search-based techniques (genetic programming, gene expression programming, artificial immune recognition system, and particle swarm optimization-based artificial neural network) consistently give better predictions, having a representation at all of the test phases. Human predictions are consistently better at two of the four test phases. We conclude that the human predictions regarding the number of faults slipping through to various test phases can be well supported by the use of search-based techniques. A combination of human and an automated search mechanism (such as any of the search-based techniques) has the potential to provide improved prediction results.

  • 197.
    Afzal, Wasif
    et al.
    Mälardalen University, School of Innovation, Design and Engineering. Blekinge Institute of Technology.
    Torkar, Richard
    Blekinge Institute of Technology.
    Feldt, Robert
    Blekinge Institute of Technology.
    Wikstrand, Greger
    KnowIT YAHM Sweden AB.
    Search-based prediction of fault-slip-through in large software projects2010In: Proceedings - 2nd International Symposium on Search Based Software Engineering, SSBSE 2010, 2010, p. 79-88Conference paper (Refereed)
    Abstract [en]

    A large percentage of the cost of rework can be avoided by ?nding more faults earlier in a software testing process. Therefore, determination of which software testing phases to focus improvements work on, has considerable industrial interest. This paper evaluates the use of ?ve different techniques, namely particle swarm optimization based arti?cial neural networks (PSO-ANN), arti?cial immune recognition systems (AIRS), gene expression programming (GEP), genetic programming (GP) and multiple regression (MR), for predicting the number of faults slipping through unit, function, integration and system testing phases. The objective is to quantify improvement potential in different testing phases by striving towards ?nding the right faults in the right phase. We have conducted an empirical study of two large projects from a telecommunication company developing mobile platforms and wireless semiconductors. The results are compared using simple residuals, goodness of ?t and absolute relative error measures. They indicate that the four search-based techniques (PSOANN, AIRS, GEP, GP) perform better than multiple regression for predicting the fault-slip-through for each of the four testing phases. At the unit and function testing phases, AIRS and PSO-ANN performed better while GP performed better at integration and system testing phases. The study concludes that a variety of search-based techniques are applicable for predicting the improvement potential in different testing phases with GP showing more consistent performance across two of the four test phases.

  • 198.
    Agasisti, Tommaso
    et al.
    Politecn Milan.
    Catalano, Giuseppe
    Landoni, Paolo
    Politecn Milan.
    Verganti, Roberto
    Politecn Milan.
    Evaluating the performance of academic departments: an analysis of research-related output efficiency2012In: Research Evaluation, ISSN 0958-2029, Vol. 21, no 1, p. 2-14Article in journal (Refereed)
    Abstract [en]

    In this article we investigated whether academic departments do experience a trade-off among different research outputs. More specifically, we define four types of academic research outputs: quantity (publications); quality (citation indexes); research funds obtained through research grants; and applied research funds obtained through external orders. Subsequently, we define a department's performance through the concept of efficiency, namely the ability to maximize academic research output given an amount of inputs (facilities and human resources). Using Data Envelopment Analysis (DEA), we measure efficiency for 69 academic departments (focused on scientific subjects) located in the Lombardy Region (Italy), benefiting from a unique data set containing detailed information on research inputs and outputs. The empirical analysis shows that efficiency rankings change significantly when considering different research-related outputs and thus it highlights different research strategies among the academic departments. These different strategies emerge also considering jointly all four types of outputs: the academic departments focus on different outputs in order to obtain the highest overall efficiency scores. In the last section, policy and managerial implications have been discussed. 

  • 199.
    Agbamuche, Joy
    Mälardalen University, School of Sustainable Development of Society and Technology.
    How does the alignment of IT to business strategy affect the organisation of the IT function?2008Student thesis
    Abstract [en]

    Date: 2008-06-04

    Purpose: The primary goal of this research is to describe the IT function and examine how its alignment to an organisations strategy affects the way it is organised.

    Method: The chosen method was a purely theoretical examination with the use of the case study of Windham International as primary resource and secondary resources such as book and literature review used for the thesis.

    Research Questions: How does the alignment of IT to business strategy affect the organisation of the IT function?

    Conclusion: One of the findings was that a few researchers seem to suggest that the centralized mode of organising IT was symbolic of the past, while outsourcing and decentralization are the modern approach to organising IT. Wyndham International shows the opposite, after the introduction of the CIO in 2002, centralization was the chosen mode of organisation because that was what would best fit the new strategic approach of the organisation. Insourcing rather than outsourcing proved to be a winning formula.

  • 200.
    Agemalm, Stina
    et al.
    Mälardalen University, School of Health, Care and Social Welfare.
    Thuvander, Frida
    Mälardalen University, School of Health, Care and Social Welfare.
    Sjuksköterskors upplevelser av att vårda palliativt: En litteraturstudie2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Background: Patients who receive palliative care experience that they lose their independence through the disease and are frustrated that their body is not functioning as before. They also experience that their situation make them change their attitudes towards life. Several patients appreciate when healthcare professionals show genuine interest and the same patients have confidence in the healthcare system. Some patients experience that the healthcare professionals have no time and that their knowledge regarding their psychosocial problems is inadequate. Aim: The purpose is to describe nurses experience of nursing in palliative care. Method: Qualitative literature study with descriptive synthesis. Ten qualitative articles have been analyzed and is presented in the result. Results: After analysis, two themes were disclosed; Becoming enriched and Being challenged who described nurse’s experiences presented under five subthemes. Conclusion: Nurses perceived, among other things, that they were strengthened as a person and that they learned to re-prioritize and appreciate life. They also experienced grief over the fate of patients and it was common to take work home. Several of the nurses perceived that doctors did not give them support, others felt that their lack of experience contributed to the care worsening.

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