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  • 151.
    Bygde, Stefan
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Parametric WCET Analysis2013Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    In a real-time system, it is crucial to ensure that all tasks of the system hold their deadlines. A missed deadline in a real-time system means that the system has not been able to function correctly. If the system is safety critical, this could potentially lead to disaster. To ensure that all tasks keep their deadlines, the Worst-Case Execution Time (WCET) of these tasks has to be known.

    Static analysis analyses a safe model of the hardware together with the source or object code of a program to derive an estimate of the WCET. This estimate is guaranteed to be equal to or greater than the real WCET. This is done by making calculations which in all steps make sure that the time is exactly or conservatively estimated. In many cases, however, the execution time of a task or a program is highly dependent on the given input. Thus, the estimated worst case may correspond to some input or configuration which is rarely (or never) used in practice. For such systems, where execution time is highly input dependent, a more accurate timing analysis which take input into consideration is desired.

    In this thesis we present a method based on abstract interpretation and counting of semantic states of a program that gives a WCET in terms of some input to the program. This means that the WCET is expressed as a formula of the input rather than a constant. This means that once the input is known, the actual WCET may be more accurate than the absolute and global WCET. Our research also investigate how this analysis can be safe when arithmetic operations causes integers to wrap-around, where the common assumption in static analysis is that variables can take the value of any integer. Our method has been implemented as a prototype and as a part of a static WCET analysis tool in order to get experience with the method and to evaluate the different aspects. Our method shows that it is possible to obtain very complex and detailed information about the timing of a program, given its input.

  • 152.
    Bygde, Stefan
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Static WCET Analysis Based on Abstract Interpretation and Counting of Elements2010Licentiatavhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    In a real-time system, it is crucial to ensure that all tasks of the system holdtheir deadlines. A missed deadline in a real-time system means that the systemhas not been able to function correctly. If the system is safety critical, this canlead to disaster. To ensure that all tasks keep their deadlines, the Worst-CaseExecution Time (WCET) of these tasks has to be known. This can be done bymeasuring the execution times of a task, however, this is inflexible, time consumingand in general not safe (i.e., the worst-casemight not be found). Unlessthe task is measured with all possible input combinations and configurations,which is in most cases out of the question, there is no way to guarantee that thelongest measured time actually corresponds to the real worst case.Static analysis analyses a safe model of the hardware together with thesource or object code of a program to derive an estimate of theWCET. This estimateis guaranteed to be equal to or greater than the real WCET. This is doneby making calculations which in all steps make sure that the time is exactlyor conservatively estimated. In many cases, however, the execution time of atask or a program is highly dependent on the given input. Thus, the estimatedworst case may correspond to some input or configuration which is rarely (ornever) used in practice. For such systems, where execution time is highly inputdependent, a more accurate timing analysis which take input into considerationis desired.In this thesis we present a framework based on abstract interpretation andcounting of possible semantic states of a program. This is a general methodof WCET analysis, which is language independent and platform independent.The two main applications of this framework are a loop bound analysis and aparametric analysis. The loop bound analysis can be used to quickly find upperbounds for loops in a program while the parametric framework provides aninput-dependent estimation of theWCET. The input-dependent estimation cangive much more accurate estimates if the input is known at run-time.

  • 153.
    Bylund, Mathias
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Evaluation of OKL42009Independent thesis Basic level (university diploma), 10 poäng / 15 hpOppgave
    Abstract [en]

    Virtualization is not a new concept in computer science. It has been used since the middle of the sixties and now software companies has interested in this technology. Virtualization is used in server side to maximize the capacity and reduce power consumption. This thesis focuses on virtualization in embedded system. The technology uses a hypervisor or a virtual machine monitor as a software layer that provide the virtual machine and to isolate the underlying hardware. One of most interesting issue is that is supports several operating system and applications running on the same hardware platform and the hypervisor has complete control of system resources. The company Open Kernel Labs is one of the leading providers of embedded systems software virtualization technology and OKL4 is one of theirproducts, which is based on L4 family of second-generation microkernel’s. In this thesis, we will evaluate the kernel contains, the performance, the security and the environment of the OKL4. Finally we conclude the advantages and disadvantages of the product and technology.

  • 154.
    Bärling, Leo
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Katana databas 1.02009Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    The task to this thesis has been to create an application, Katana-databas 1.0, for analysing c-code. The generated output gets stored in a data structure which content in the end of the program run gets written in a textfile which gets used by Katana. It's a tool for reverse engineering, developed by Johan Kraft at Mälardalens institute.

    Katana-databas has got the following limitations. (1) It can only handle preprocessed files, meaning it doesn't contain any rows beginning with "#". (2) Only complete files can be handled. (3) No references to unknown functions or variables are allowed. (4) A further limitation is that the application can't handle any ADT's. It can only handle primitive types. (5) Finally the application is only written for pure c-code, and thus doesn't handle code written C++.

    The task has been solved by creating an automatically generated lexer with Flex and Bison rules in Visual Studio. There after a limited parser has been developed which purpose is to process the lexemes which the lexer generates.

    The underlying causes for the thesis is to replace Understand with Katana-databas. Katana has this far used the database in Understand, but it contains closed source code. What is seeked is open source code, which Katana-databas is based on.

  • 155.
    Cai, Simin
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Systematic Design and Analysis of Customized Data Management for Real-Time Database Systems2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Modern real-time data-intensive systems generate large amounts of data that are processed using complex data-related computations such as data aggregation. In order to maintain logical data consistency and temporal correctness of the computations, one solution is to model the latter as transactions and manage them using a Real-Time Database Management System (RTDBMS). Ideally, depending on the particular system, the transactions are customized with the desired logical and temporal correctness properties, which should be enforced by the customized RTDBMS via appropriate transaction management mechanisms. However, developing such a data management solution with high assurance is not easy, partly due to inadequate support for systematic specification and analysis during the design. Firstly, designers do not have means to identify the characteristics of the computations, especially data aggregation, and to reason about their implications. Design flaws might not be discovered early enough, and thus they may propagate to the implementation. Secondly, meeting more properties simultaneously might not be possible, so trading-off the less critical ones for the critical one, for instance, temporal correctness, is sometimes required. Nevertheless, trade-off analysis of conflicting properties, such as transaction atomicity, isolation and temporal correctness, is mainly performed ad-hoc, which increases the risk of unpredictable behavior.

    In this thesis, we address the above problems by showing how to systematically design and provide assurance of transaction-based data management with data aggregation support, customized for real-time systems. We propose a design process as our methodology for the systematic design and analysis of the trade-offs between desired properties, which is facilitated by a series of modeling and analysis techniques. Our design process consists of three major steps as follows: (i) Specifying the data-related computations, as well as the logical data consistency and temporal correctness properties, from system requirements, (ii) Selecting the appropriate transaction models to model the computations, and deciding the corresponding transaction management mechanisms that can guarantee the properties, via formal analysis, and, (iii) Generating the customized RTDBMS with the proved transaction management mechanisms, via configuration or implementation. In order to support the first step of our process, we propose a taxonomy of data aggregation processes for identifying their common and variable characteristics, based on which their inter-dependencies can be captured, and the consequent design implications can be reasoned about. Tool support is provided to check the consistency of the data aggregation design specifications. To specify transaction atomicity, isolation and temporal correctness, as well as the transaction management mechanisms, we also propose a Unified Modeling Language (UML) profile with explicit support for these elements. The second step of our process relies on the systematic analysis of trade-offs between transaction atomicity, isolation and temporal correctness. To achieve this, we propose two formal frameworks for modeling transactions with abort recovery, concurrency control, and scheduling. The first framework UPPCART utilizes timed automata as the underlying formalism, based on which the desired properties can be verified by model checking. The second framework UPPCART-SMC models the system as stochastic timed automata, which allows for probabilistic analysis of the properties for large complex RTDBMS using statistical model checking. The encoding of high-level UTRAN specifications into corresponding formal models is supported by tool automation, which we also propose in this thesis. The applicability and usefulness of our proposed techniques are validated via several industrial use cases focusing on real-time data management.

  • 156.
    Cai, Simin
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Gallina, Barbara
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Nyström, Dag
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Seceleanu, Cristina
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    DAGGTAX: A taxonomy of data aggregation processes2017Inngår i: Lecture Notes in Computer Science, vol. 10563, Springer Verlag , 2017, s. 324-339Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Data aggregation processes are essential constituents for data management in modern computer systems, such as decision support systems and Internet of Things (IoT) systems. Due to the heterogeneity and real-time constraints in such systems, designing appropriate data aggregation processes often demands considerable effort. A study on the characteristics of data aggregation processes is then desirable, as it provides a comprehensive view of such processes, potentially facilitating their design, as well as the development of tool support to aid designers. In this paper, we propose a taxonomy called DAGGTAX, which is a feature diagram that models the common and variable characteristics of data aggregation processes, with a special focus on the real-time aspect. The taxonomy can serve as the foundation of a design tool, which we also introduce, enabling designers to build an aggregation process by selecting and composing desired features, and to reason about the feasibility of the design. We apply DAGGTAX on industrial case studies, showing that DAGGTAX not only strengthens the understanding, but also facilitates the model-driven design of data aggregation processes. © 2017, Springer International Publishing AG.

  • 157.
    Cai, Simin
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Gallina, Barbara
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Nyström, Dag
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Seceleanu, Cristina
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Specification and Automated Verification of Atomic Concurrent Real-Time Transactions2019Manuskript (preprint) (Annet vitenskapelig)
  • 158.
    Caldegren, André
    Mälardalens högskola, Akademin för innovation, design och teknik.
    The Influence of Bitcoin on Ethereum Price Predictions2018Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Cryptocurrencies are a cryptography based technology, that has increased massively in popularity in recent years. These currencies are traded on markets that specialize in cryptocurrency trade. There, you can trade one cryptocurrency for another, or buy one with real world money. These markets are quite volatile, meaning that the price of most cryptocurrencies swing up and down a lot. The largest cryptocurrency is Bitcoin, but there is also more than 1500 smaller ones, that goes by the name alternative coins, or altcoins. This thesis will try to find out if it is possible to make accurate predictions about the future price of the altcoin Ethereum, and also see if Bitcoin may have some influence over the price of the selected altcoin. The predictions were made with the use of an artificial neural network, an LSTM network, that was trained on labeled data from 2017. The predictions were then made in intervals of one hour ahead, six hours ahead, and one day ahead through early 2018. The predictions showed that it is possible to make somewhat accurate predictions about the future. The predictions that were made one hour ahead were more accurate than both the six hours ahead predictions and the full day ahead predictions. By comparing the loss rates of the neural networks that were only trained on Ethereum, with the loss rates of the networks that trained on both Bitcoin and Ethereum, is was made clear that training on both cryptocurrencies did not improve the prediction accuracies.

  • 159.
    Campeanu, Gabriel
    Mälardalens högskola, Akademin för innovation, design och teknik.
    An investigation of the dual priorityscheduling paradigm2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Real-time computing paradigm is being pervasively deployed in many critical and non-critical applicationssuch as aerospace and telecommunication systems. Most of these systems employ a preemptiveFixed Priority Scheduling (FPS) policy to schedule real-time tasks. Fixed priority scheduling is knownfor its implementation simplicity and low run-time overheads. However, FPS may not be able to use100% of the processor time, when compared to dynamic priority scheduling policies such as the EarliestDeadline First (EDF) scheduling scheme. Dynamic priority scheduling scheme, on the other hand, has tore-calculate the priorities on-line and hence may have significantly high run-time overheads.

    In this thesis, we investigate a novel scheduling scheme, known as the Dual Priority Scheduling scheme,that can potentially guarantee a feasible schedule. The main advantage of using a dual priority scheduleris that, it can achieve the implementation simplicity of a FPS scheme, while potentially assuring 100%processor utilization similar to EDF. Alan Burns proved the optimality of the dual priority scheme for twotasks, leaving its optimality for n tasks as an open problem. We investigate the optimality of dual priorityscheduling for three tasks, using simulations. We propose and evaluate three different approaches: lastchance method, slack method and brute force method, to calculate the dual priorities and the time intervalswhere these priorities are valid.

    Our evaluations showed that, of the proposed heuristics, the extended slack method which is a variationof the slack method, performed same as the brute force method. An interesting observation was that,the brute force and the extended slack methods could not schedule the same task sets, nor was the tasksets schedulable using any of the proposed methods.

  • 160.
    Cano, J.
    et al.
    Instituto de Telecomunicações - Fac de Engenharia, Universidade Do Porto, Porto, Portugal.
    Pereira, A.
    Instituto de Telecomunicações - Fac de Engenharia, Universidade Do Porto, Porto, Portugal.
    Oliveira, L.
    Instituto de Telecomunicações - Fac de Engenharia, Universidade Do Porto, Porto, Portugal.
    Almeida, Luis
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. Instituto de Telecomunicações - Fac de Engenharia, Universidade Do Porto, Porto, Portugal.
    Scheduling feedback for scalability and reliability in a streaming multicast protocol2015Inngår i: IEEE International Workshop on Factory Communication Systems - Proceedings, WFCS, 2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The number of mobile devices accessing the Internet is continuously increasing, creating new problems. For example, when many wireless clients try to access the same video stream in the same hot spot, multicast transmission must be used. However, multicast packets are unacknowledged and may present a high loss rate under adverse conditions which may jeopardize the quality of the streaming. In a severe scenario, packet losses may affect all video frames, preventing the clients from receiving the video stream at all. Therefore, we propose a novel reliable multicast protocol, tailored to streaming applications, that also scales to many clients under the same access point. It uses a feedback repeat request mechanism per client and such requests are adequately scheduled by the streaming server. This mechanism, which is the focus of this paper, also allows differentiating the quality of service provided to the clients, polling their feedback independently. We show experimental and simulation results that confirm the desired scalability and reliable streaming, with efficient bandwidth usage. The results also show a clear superiority in mitigating lost packets with respect to other approaches to the same problem, with benefits reaching and even going beyond one order of magnitude in packets recovery.

  • 161.
    Capannini, Gabriele
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Larsson, Thomas B
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Adaptive Collision Culling for Large-Scale Simulations by a Parallel Sweep and Prune Algorithm2016Inngår i: Proceedings of the 16th Eurographics Symposium on Parallel Graphics and Visualization EGPGV 2016, Groningen, Netherlands: Eurographics Association , 2016, s. 1-10Konferansepaper (Fagfellevurdert)
  • 162.
    Capannini, Gabriele
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lucchese, C.
    Istituto di Scienza e Tecnologie dell'Informazione (ISTI) of the National Research Council of Italy (CNR), Pisa, Italy.
    Nardini, F. M.
    Istituto di Scienza e Tecnologie dell'Informazione (ISTI) of the National Research Council of Italy (CNR), Pisa, Italy.
    Orlando, S.
    University Ca’ Foscari of Venice, Italy.
    Perego, R.
    Istituto di Scienza e Tecnologie dell'Informazione (ISTI) of the National Research Council of Italy (CNR), Pisa, Italy.
    Tonellotto, N.
    Istituto di Scienza e Tecnologie dell'Informazione (ISTI) of the National Research Council of Italy (CNR), Pisa, Italy.
    Quality versus efficiency in document scoring with learning-to-rank models2016Inngår i: Information Processing & Management, ISSN 0306-4573, E-ISSN 1873-5371, Vol. 52, nr 6, s. 1161-1177Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Learning-to-Rank (LtR) techniques leverage machine learning algorithms and large amounts of training data to induce high-quality ranking functions. Given a set of documents and a user query, these functions are able to precisely predict a score for each of the documents, in turn exploited to effectively rank them. Although the scoring efficiency of LtR models is critical in several applications – e.g., it directly impacts on response time and throughput of Web query processing – it has received relatively little attention so far. The goal of this work is to experimentally investigate the scoring efficiency of LtR models along with their ranking quality. Specifically, we show that machine-learned ranking models exhibit a quality versus efficiency trade-off. For example, each family of LtR algorithms has tuning parameters that can influence both effectiveness and efficiency, where higher ranking quality is generally obtained with more complex and expensive models. Moreover, LtR algorithms that learn complex models, such as those based on forests of regression trees, are generally more expensive and more effective than other algorithms that induce simpler models like linear combination of features. We extensively analyze the quality versus efficiency trade-off of a wide spectrum of state-of-the-art LtR, and we propose a sound methodology to devise the most effective ranker given a time budget. To guarantee reproducibility, we used publicly available datasets and we contribute an open source C++ framework providing optimized, multi-threaded implementations of the most effective tree-based learners: Gradient Boosted Regression Trees (GBRT), Lambda-Mart (Λ-MART), and the first public-domain implementation of Oblivious Lambda-Mart (Ωλ-MART), an algorithm that induces forests of oblivious regression trees. We investigate how the different training parameters impact on the quality versus efficiency trade-off, and provide a thorough comparison of several algorithms in the quality-cost space. The experiments conducted show that there is not an overall best algorithm, but the optimal choice depends on the time budget.

  • 163.
    Capilla, R.
    et al.
    Universidad Rey Juan Carlos, Madrid, Spain.
    Gallina, Barbara
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Cetina, C.
    Universidad San Jorge, Zaragoza, Spain.
    Foreword2018Inngår i: Lect. Notes Comput. Sci., Springer Verlag , 2018Konferansepaper (Fagfellevurdert)
  • 164.
    Capilla, R.
    et al.
    Rey Juan Carlos University, Madrid, Spain.
    Gallina, Barbara
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Cetina Englada, C.
    Universidad San Jorge, Zaragoza, Spain.
    The new era of software reuse2019Inngår i: Journal of Software: Evolution and Process, ISSN 2047-7473, E-ISSN 2047-7481, Vol. 31, nr 8, artikkel-id e2221Artikkel i tidsskrift (Fagfellevurdert)
  • 165.
    Cappiello, Antonio
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Improving software evolvabilityby exploiting change history and software metrics2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
  • 166.
    Carlie, Michael
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Ray Tracing Non-Polygonal Objects: Implementation and Performance Analysis using Embree2016Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Free-form surfaces and implicit surfaces must be tessellated before being rendered with rasterization techniques. However ray tracing provides the means to directly render such objects without the need to first convert into polygonal meshes. Since ray tracing can handle triangle meshes as well, the question of which method is most suitable in terms of performance, quality and memory usage is addressed in this thesis. Bézier surfaces and NURBS surfaces along with basic algebraic implicit surfaces are implemented in order to test the performance relative to polygonal meshes approximating the same objects. The parametric surfaces are implemented using an iterative Newtonian method that converges on the point of intersection using a bounding volume hierarchy that stores the initial guesses. Research into intersecting rays with parametric surfaces is surveyed in order to find additional methods that speed up the computation. The implicit surfaces are implemented using common direct algebraic methods. All of the intersection tests are implemented using the Embree ray tracing API as well as a SIMD library in order to achieve interactive framerates on a CPU. The results show that both Bézier surfaces and NURBS surfaces can achieve interactive framerates on a CPU using SIMD computation, with Bézier surfaces coming close to the performance of polygonal counterparts. The implicit surfaces implemented outperform even the simplest polygonal approximations.

  • 167.
    Carlson, Jan
    Mälardalens högskola, Institutionen för datavetenskap och elektronik.
    Event Pattern Detection for Embedded Systems2007Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Events play an important role in many computer systems, from small reactive embedded applications to large distributed systems. Many applications react to events generated by a graphical user interface or by external sensors that monitor the system environment, and other systems use events for communication and synchronisation between independent subsystems. In some applications, however, individual event occurrences are not the main point of concern. Instead, the system should respond to certain event patterns, such as "the start button being pushed, followed by a temperature alarm within two seconds". One way to specify such event patterns is by means of an event algebra with operators for combining the simple events of a system into specifications of complex patterns.

    This thesis presents an event algebra with two important characteristics. First, it complies with a number of algebraic laws, which shows that the algebra operators behave as expected. Second, any pattern represented by an expression in this algebra can be efficiently detected with bounded resources in terms of memory and time, which is particularly important when event pattern detection is used in embedded systems, where resource efficiency and predictability are crucial.

    In addition to the formal algebra semantics and an efficient detection algorithm, the thesis describes how event pattern detection can be used in real-time systems without support from the underlying operating system, and presents schedulability theory for such systems. It also describes how the event algebra can be combined with a component model for embedded system, to support high level design of systems that react to event patterns.

  • 168.
    Carlsson, Mikael
    Mälardalens högskola, Akademin för innovation, design och teknik.
    VIRTUAL REALITY – STREAMING AND CONCEPTS OF MOVEMENT TRACKING2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    This thesis was created to support research and development of a virtual reality application allowing users to explore a virtual world. The main focus would be on creating a solution for streaming the screen of a PC to a mobile phone, for the purpose of taking advantage of the computer’s rendering capability. This would result in graphics with higher quality than if the rendering was done by the phone. The resulting application is a prototype, able to stream images from one PC to another, with a delay of about 200ms. The prototype uses TCP as its transmission protocol and also uses the Graphics Device Interface (GDI) to capture the host computer’s screen.This thesis also provides some information and reflections on different concepts of tracking the movement of the user, e.g. body worn sensors used to capture relative positions and translating into a position and orientation of the user. The possibility of using magnetic fields, tracking with a camera, inertial sensors, and finally triangulation and trilateration together with Bluetooth, are all concepts investigated in this thesis. The purpose of investigating these methods is to help with the development of a motion tracking system where the user is not restricted by wires or cameras, although one camera solution was also reviewed.

  • 169.
    Carlsson, Tobias
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Automatiserat analys- och klassificeringsprogram för bilder / Automated image analyzing and categorizing program2011Independent thesis Basic level (degree of Bachelor), 15 poäng / 22,5 hpOppgave
    Abstract [en]

    Today, to automatically distinguish photographs from computer rendered illustrations on theinternet, programs are used to correctly tag images. Search engines use these tags to quickly listrelevant images sought by users.Mostphotos, a company which buys and sells images online, needed a similar program that was notonly precise, but also fast in order to index the thousands of images uploaded to its website everyday.The foundation of such a program had previously been implemented. The aim of this project wasprimarily to port the core of the existing system to C++ code, and secondly to improve the program’saccuracy.The ported version was implemented as a black box, with only a file path as input and a valuebetween 0 and 1.0 as output to indicate the likelihood of the image being a photograph. The portedversion is significantly faster and several percentage points more accurate than the old system.The program’s limitation is that the sample volume used to calibrate the sub-algorithms is too small.This could be solved by increasing the sample volume manually. The program includes tools for thisin the form of automatic calibration and a stand-alone application for algorithm tuning.

  • 170.
    Carnebro, Anna-Carin
    Mälardalens högskola, Institutionen för innovation, design och produktutveckling.
    ABB Communication Center: och informationsdesign2006Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    C-uppsatsen baseras på en fallstudie över ABB Communication Centers internkommunikation, den övergripande kommunikativa enheten på ABB Sverige AB. Syftet är att beskriva informationsdesignens roll i såväl den dagliga verksamheten som den övergripande inställningen till det internkommunikativa arbetet. Samt jämföra teorier inom organisations- och kommunikationsvetenskap samt informationsdesign och resultaten från den empiriska undersökningen.

  • 171.
    Casalaro, Giuseppina Lucia
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Cattivera, Giulio
    MODEL-DRIVEN ENGINEERING FOR MOBILE ROBOT SYSTEMS: A SYSTEMATIC MAPPING STUDY2015Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The development of autonomous Mobile Robot Systems is attracting nowadays more and moreinterest from both researchers and practitioners, mainly because they may open for a wide rangeof improvements for quality of life. Mobile robots are systems capable of accomplishing missionsby moving in an unknown environment without human supervision. Throughout mechanisms ofdetection, communication and adaptation, they can adapt their behavior according to changes ofthe environment. Individual robots can even join teams of autonomous mobile robots that, throughindividual tasks, accomplish common missions. These are called Mobile Multi-Robot Systems andare meant to perform missions that a single robot would not be able to carry out by itself.When it comes to the development of Mobile Robot Systems, currently there is no standard methodology.This is mainly due to the complexity of the domain and the variety of di↵erent platformsthat are available on the market. A promising methodology that recently has gained attention insoftware industry for its ability of mitigating complexity and boosting platform-independence, isModel-Driven Engineering.This thesis proposes a systematic mapping study on the state-of-the-art of Model-Driven Engineeringfor Mobile Robot Systems. Through our contribution, researchers can get a picture of theactual trends and open challenges for further research, while practitioners can realize the suitabilityof Model-Driven Engineering by checking to what extent it has been applied to real-world projects.

  • 172.
    Castagnari, C.
    et al.
    Division of Computer Science, Smart Mobility Lab, University of Camerino, Via Madonna delle Carceri 9, Camerino, MC, Italy.
    de Berardinis, J.
    Division of Computer Science, Smart Mobility Lab, University of Camerino, Via Madonna delle Carceri 9, Camerino, MC, Italy.
    Forcina, G.
    Division of Computer Science, Smart Mobility Lab, University of Camerino, Via Madonna delle Carceri 9, Camerino, MC, Italy.
    Jafari, A.
    School of Computer Science, Reykjavik University, Menntavegur 1, Reykjavik, Iceland.
    Sirjani, Marjan
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. School of Computer Science, Reykjavik University, Reykjavik, Iceland.
    Lightweight preprocessing for agent-based simulation of smart mobility initiatives2018Inngår i: Lect. Notes Comput. Sci., Springer Verlag , 2018, s. 541-557Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Understanding the impacts of a mobility initiative prior to deployment is a complex task for both urban planners and transport companies. To support this task, Tangramob offers an agent-based simulation framework for assessing the evolution of urban traffic after the introduction of new mobility services. However, Tangramob simulations are computationally expensive due to their iterative nature. Thus, we simplified the Tangramob model into a Timed Rebeca (TRebeca) model and we designed a tool-chain that generates instances of this model starting from the same Tangramob’s inputs. Running TRebeca models allows users to get an idea of how mobility initiatives affect the system performance, in a short time, without resorting to the simulator. To validate this approach, we compared the output of both the simulator and the TRebeca model on a collection of mobility initiatives. Results show a correlation between them, thus demonstrating the usefulness of using TRebeca models for unconventional contexts of application.

  • 173.
    Castellanos Ardila, Julieth Patricia
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Facilitating Automated Compliance Checking of Processes against Safety Standards2019Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    A system is safety-critical if its malfunctioning could have catastrophic consequences for people, property or the environment, e.g., the failure in a car's braking system could be potentially tragic. To produce such type of systems, special procedures, and strategies, that permit their safer deployment into society, should be used. Therefore, manufacturers of safety-critical systems comply with domain-specific safety standards, which embody the public consensus of acceptably safe. Safety standards also contain a repository of expert knowledge and best practices that can, to some extent, facilitate the safety-critical system’s engineering. In some domains, the applicable safety standards establish the accepted procedures that regulate the development processes. For claiming compliance with such standards, companies should adapt their practices and provide convincing justifications regarding the processes used to produce their systems, from the initial steps of the production. In particular, the planning of the development process, in accordance with the prescribed process-related requirements specified in the standard, is an essential piece of evidence for compliance assessment. However, providing such evidence can be time-consuming and prone-to-error since it requires that process engineers check the fulfillment of hundreds of requirements based on their processes specifications. With access to suitable tool-supported methodologies, process engineers would be able to perform their job efficiently and accurately.

    Safety standards prescribe requirements in natural language by using notions that are subtly similar to the concepts used to describe laws. In particular, requirements in the standards introduce conditions that are obligatory for claiming compliance. Requirements also define tailoring rules, which are actions that permit to comply with the standard in an alternative way. Unfortunately, current approaches for software verification are not furnished with these notions, which could make their use in compliance checking difficult. However, existing tool-supported methodologies designed in the legal compliance context, which are also proved in the business domain, could be exploited for defining an adequate automated compliance checking approach that suits the conditions required in the safety-critical context.

    The goal of this Licentiate thesis is to propose a novel approach that combines: 1) process modeling capabilities for representing systems and software process specifications, 2) normative representation capabilities for interpreting the requirements of the safety standards in an adequate machine-readable form, and 3) compliance checking capabilities to provide the analysis required to conclude whether the model of a process corresponds to the model with the compliant states proposed by the standard's requirements. Our approach contributes to facilitating compliance checking by providing automatic reasoning from the requirements prescribed by the standards, and the description of the process they regulate. It also contributes to cross-fertilize two communities that were previously isolated, namely safety-critical and legal compliance contexts. Besides, we propose an approach for mastering the interplay between highly-related standards. This approach includes the reuse capabilities provided by SoPLE (Safety-oriented Process Line Engineering), which is a methodological approach aiming at systematizing the reuse of process-related information in the context of safety-critical systems. With the addition of SoPLE, we aim at planting the seeds for the future provision of systematic reuse of compliance proofs. Hitherto, our proposed methodology has been evaluated with academic examples that show the potential benefits of its use.

  • 174.
    Castellanos Ardila, Julieth Patricia
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Investigation of an OSLC-domain targeting ISO 26262: Focus on the left side of the Software V-model2016Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Industries have adopted a standardized set of practices for developing their products. In the automotive domain, the provision of safety-compliant systems is guided by ISO 26262, a standard that specifies a set of requirements and recommendations for developing automotive safety-critical systems. For being in compliance with ISO 26262, the safety lifecycle proposed by the standard must be included in the development process of a vehicle. Besides, a safety case that shows that the system is acceptably safe has to be provided. The provision of a safety case implies the execution of a precise documentation process. This process makes sure that the work products are available and traceable. Further, the documentation management is defined in the standard as a mandatory activity and guidelines are proposed/imposed for its elaboration. It would be appropriate to point out that a well-documented safety lifecycle will provide the necessary inputs for the generation of an ISO 26262-compliant safety case. The OSLC (Open Services for Lifecycle Collaboration) standard and the maturing stack of semantic web technologies represent a promising integration platform for enabling semantic interoperability between the tools involved in the safety lifecycle. Tools for requirements, architecture, development management, among others, are expected to interact and shared data with the help of domains specifications created in OSLC.This thesis proposes the creation of an OSLC tool-chain infrastructure for sharing safety-related information, where fragments of safety information can be generated. The steps carried out during the elaboration of this master thesis consist in the identification, representation, and shaping of the RDF resources needed for the creation of a safety case. The focus of the thesis is limited to a tiny portion of the ISO 26262 left-hand side of the V-model, more exactly part 6 clause 8 of the standard:  Software unit design and implementation. Regardless of the use of a restricted portion of the standard during the execution of this thesis, the findings can be extended to other parts, and the conclusions can be generalize.This master thesis is considered one of the first steps towards the provision of an OSLC-based and ISO 26262-compliant methodological approach for representing and shaping the work products resulting from the execution of the safety lifecycle, documentation required in the conformation of an ISO-compliant safety case.

  • 175.
    Castellanos Ardila, Julieth Patricia
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Gallina, Barbara
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Governatori, Guido
    Data61, CSIRO, Australia.
    Lessons Learned while formalizing ISO 26262 for Compliance Checking2018Inngår i: Proceedings of the 2nd Workshop on Technologies for Regulatory Compliance (TeReCom), 2018, s. 5-16Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A confirmation review of the safety plan is required during compliance assessment with ISO 26262. Its production could be facilitated by creating a specification of the standard’s requirements in FCL (Formal Contract Logic), which is a language that can be used to automatically checking compliance. However, we have learned, via previous experiences, that interpreting ISO 26262 requirements and specifying them in FCL is complex. Thus, we perform a formalization-oriented pre-processing of ISO 26262 to find effective ways to proceed with this task. In this paper, we present the lessons learned from this pre-processing which includes the identification of the essential normative parts to be formalized, the identification of SCP (Safety Compliance Patterns) and its subsequent documentation as templates, and the definition of a methodological guideline to facilitate the formalization of normative clauses. Finally, we illustrate the defined methodology by formalizing ISO 26262 part 3 and discuss our findings.

  • 176.
    Castellanos Ardila, Julieth Patricia
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Gallina, Barbara
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    UL Muram, Faiz
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Transforming SPEM 2.0-compatible process models into models checkable for compliance2018Inngår i: Communications in Computer and Information Science, Springer Verlag , 2018, Vol. 918, s. 233-247Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Manual compliance with process-based standards is time-consuming and prone-to-error. No ready-to-use solution is currently available for increasing efficiency and confidence. In our previous work, we have presented our automated compliance checking vision to support the process engineer’s work. This vision includes the creation of a process model, given by using a SPEM 2.0 (Systems & Software Process Engineering Metamodel)-reference implementation, to be checked by Regorous, a compliance checker used in the business context. In this paper, we move a step further for the concretization of our vision by defining the transformation, necessary to automatically generate the models required by Regorous. Then, we apply our transformation to a small portion of the design phase recommended in the rail sector. Finally, we discuss our findings, and present conclusions and future work. 

  • 177.
    Castillejo, P.
    et al.
    Universidad Politecnica de Madrid, Madrid, Spain.
    Curuklu, Baran
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Fresco, R.
    CNR - IMAMOTER, Ferrara, Italy.
    Johansen, G.
    SINTEF, Trondheim, Norway.
    Bilbao-Arechabala, S.
    Tecnalia, Bizkaia, Spain.
    Martinez-Rodriguez, B.
    Tecnalia, Bizkaia, Spain.
    Pomante, L.
    Università degli Studi dell'Aquila, Center of Excellence DEWS, L'Aquila, Italy.
    Martinez-Ortega, J. -F
    Universidad Politecnica de Madrid, Madrid, Spain.
    Santic, M.
    Università degli Studi dell'Aquila, Center of Excellence DEWS, L'Aquila, Italy.
    The AFarCloud ECSEL Project2019Inngår i: Proceedings - Euromicro Conference on Digital System Design, DSD 2019, Institute of Electrical and Electronics Engineers Inc. , 2019, s. 414-419Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Farming is facing many economic challenges in terms of productivity and cost-effectiveness. Labor shortage partly due to depopulation of rural areas, especially in Europe, is another challenge. Domain specific problems such as accurate identification and proper quantification of pathogens affecting plant and animal health are key factors for minimizing economical risks, and not risking human health. The ECSEL AFarCloud (Aggregate FARming in the CLOUD) project will provide a distributed platform for autonomous farming that will allow the integration and cooperation of agriculture Cyber Physical Systems in real-time in order to increase efficiency, productivity, animal health, food quality and reduce farm labour costs. This platform will be integrated with farm management software and will support monitoring and decision-making solutions based on big data and real-time data mining techniques. 

  • 178.
    Causevic, Adnan
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Potena, P.
    RISE Research Institutes of Sweden AB, Sweden.
    Wiklund, K.
    Ericsson AB, Sweden.
    Borg, M.
    RISE Research Institutes of Sweden AB.
    Message from the nexta 2019 chairs2019Inngår i: Proceedings - 2019 IEEE 12th International Conference on Software Testing, Verification and Validation Workshops, ICSTW 2019, Institute of Electrical and Electronics Engineers Inc. , 2019, artikkel-id 8728944Konferansepaper (Annet vitenskapelig)
  • 179.
    Causevic, Adnan
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Sajeev, Abdulkadir
    University of New England, Australia.
    Punnekkat, Sasikumar
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Redefining the role of testers in organisational transition to agile methodologies2009Inngår i: International Conference on Software, Services & Semantic Technologies (S3T), Sofia, Bulgaria, 2009Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Many challenges confront companies when they change their current software development process to an agile development methodology. Those challenges could be rather difficult but one that requires considerable attention is the integration of testing with development. This is because in heavyweight processes, as in the traditional waterfall approach, testing is a phase often conducted by testers as part of a quality assurance team towards the end of the development cycle whereas in the agile methodology testing is part of a continuous development activity with no specific “tester” role defined. In this paper we consider several options for testers when an organisation transit to agile methodology, and propose a new project mentor role for them. This role aims to utilize the knowledge that testers already have in both the business domain and the development technology together with their expertise in quality practices. This role will enhance the stature of testers as well as enable the company to effectively deploy the testers in the new environment. Motivations and benefits for this role are presented in this paper together with our plan for evaluation of this proposal.

  • 180.
    Causevic, Adnan
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Sundmark, Daniel
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Punnekkat, Sasikumar
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Factors Limiting Industrial Adoption of Test Driven Development: A Systematic Review2011Inngår i: 4th IEEE International Conference on Software Testing, Verification, and Validation, ICST 2011; Berlin; 21 March 2011 through 25 March 2011, 2011, s. 337-346Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Test driven development (TDD) is one of the basic practices of agile software development and both academia and practitioners claim that TDD, to a certain extent, improves the quality of the code produced by developers. However, recent results suggest that this practice is not followed to the extent preferred by industry. In order to pinpoint specific obstacles limiting its industrial adoption we have conducted a systematic literature review on empirical studies explicitly focusing on TDD as well as indirectly addressing TDD. Our review has identified seven limiting factors viz., increased development time, insufficient TDD experience/knowledge, lack of upfront design, domain and tool specific issues, lack of developer skill in writing test cases, insufficient adherence to TDD protocol, and legacy code. The results of this study is of special importance to the testing community, since it outlines the direction for further detailed scientific investigations as well as highlights the requirement of guidelines to overcome these limiting factors for successful industrial adoption of TDD.

  • 181.
    Causevic, Aida
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lisova, Elena
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Ashjaei, Seyed Mohammad Hossein
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Ashgar, Syed Usman
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    On incorporating security parameters in service level agreements2019Inngår i: CLOSER 2019 - Proceedings of the 9th International Conference on Cloud Computing and Services Science, SciTePress , 2019, s. 48-57Konferansepaper (Fagfellevurdert)
    Abstract [en]

    With development of cloud computing new ways for easy, on-demand, Internet-based access to computing resources have emerged. In such context a Service Level Agreement (SLA) enables contractual agreements between service providers and users. Given an SLA, service users are able to establish trust in that the service outcome corresponds to what they have demanded during the service negotiation process. However, an SLA provides a limited support outside of basic Quality of Service (QoS) parameters, especially when it comes to security. We find security as an important factor to be included in adjusting an SLA according to user defined objectives. Incorporating it in an SLA is challenging due to difficulty to provide complete and quantifiable metrics, thus we propose to focus on a systematic way of addressing security using the security process. In this paper we investigate ways in which security might be incorporated already in the service negotiation process and captured in an SLA. We propose a corresponding process to develop and maintain an SLA that considers both design-, and run-time. To demonstrate the approach we built upon the existing SLAC language and extend its syntax to support security. An example of a service being provided with security guarantees illustrates the concept.

  • 182.
    Causevic, Aida
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Pettersson, Paul
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Seceleanu, Cristina
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Analyzing Resource-Usage Impact on Component-Based Systems Performance and Reliability2008Inngår i: 2008 International Conference on Computational Intelligence for Modelling Control & Automation, Los Alamitos, CA: IEEE Computer Society , 2008, s. 302-308Konferansepaper (Fagfellevurdert)
    Abstract [en]

    An early prediction of resource utilization and its impacton system performance and reliability can reduce theoverall system cost, by allowing early correction of detectedproblems, or changes in development plans with minimizedoverhead. Nowadays, researchers are using both academicand commercial models to predict such attributes, by measuringthem at earliest stages of system development. Inthis paper, we give a short overview of existing predictionmodels for performance and reliability, targeting popularcomponent-based frameworks. Next, we describe our ownapproach for tackling such predictions, through an illustrationon a small example that deals with estimations of energyconsumption.

  • 183.
    Cavaco, Philip
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Artificial Grammar Recognition Using Spiking Neural Networks2009Independent thesis Advanced level (degree of Master (Two Years)), 80 poäng / 120 hpOppgave
    Abstract [en]

    This thesis explores the feasibility of Artificial Grammar (AG) recognition using spiking neural networks. A biologically inspired minicolumn model is designed as the base computational unit. Two network topographies are defined with different ideologies. Both networks consists of minicolumn models, referred to as nodes, connected with excitatory and inhibitory connections. The first network contains nodes for every bigram and trigram producible by the grammar’s finite state machine (FSM). The second network has only nodes required to identify unique internal states of the FSM. The networks produce predictable activity for tested input strings. Future work to improve the performance of the networks is discussed. The modeling framework developed can be used by neurophysiological research to implement network layouts and compare simulated performance characteristics to actual subject performance.

  • 184.
    Cavrak, Igor
    et al.
    Univ Zagreb, Croatia..
    Bosnic, Ivana
    Univ Zagreb, Croatia..
    Ciccozzi, Federico
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Mirandola, Raffaela
    Politecn Milan, Italy..
    Resilience of distributed student teams to stress factors: A longitudinal case-study2019Inngår i: Information and Software Technology, ISSN 0950-5849, E-ISSN 1873-6025, Vol. 114, s. 258-274Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Context: Teaching global software engineering is continuously evolving and improving to prepare future software engineers adequately. Geographically distributed work in project-oriented software development courses is both demanding and rewarding for student teams, who are susceptible to various risks stemming from different internal and external factors, being the sources of stress and impacting team performance. Objective: In this paper, we analyze the resilience of teams of students working in a geographically fully distributed setting. Resilience is analyzed in relation to two representative stress factors: non-contributing team members and changes to customer project requirements. We also reason on team collaboration patterns and analyze potential dependencies among these collaboration patterns, team resilience and stress factors. Method: We conduct a longitudinal case-study over five years on our Distributed Software Development (DSD) course. Based on empirical data, we study team resilience to two stress factors by observing their impact on process and product quality aspects of team performance. The same performance aspects are studied for identified collaboration patterns, and bidirectional influence between patterns and resilience is investigated. Results: Teams with up to two non-contributing members experience graceful degradation of performance indicators. A large number of non-contributing students almost guarantees the occurrence of educationally undesirable collaboration patterns. Exposed to requirements change stress, less resilient teams tend to focus on delivering the functional product rather than retaining a proper development process. Conclusions: Practical recommendations to be applied in contexts similar to our case have been provided at the end of the study. They include suggestions to mitigate the sources of stress, for example, by careful planning the team organization and balancing the number of regular and exchange students, or by discussing the issue of changing requirements with the external customers before the start of the project.

  • 185.
    Cedergren, Stefan
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Performance in Product Development - The Case of Complex Products2011Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    This research addresses the concept of performance in the development of complex products. More specifically, its aim is to study how performance is perceived and measured within large global companies, and how performance measurement systems can be designed in a systematic way.

    The exploratory results regard how performance is currently perceived and measured. It is argued that performance measurements are focused on the later stages of the development of complex products, thus making it difficult to perform changes during the development. The focus is on lagging rather than leading indicators of performance, hence it is concluded that focus is on reporting the result rather than the causes of the result. In line with these findings is the weak link between what managers perceive as success factors and what is measured, the perception of performance being influenced by what is measured, rather than the reverse.

    The prescriptive results focus on the development of models and frameworks to be used during the development of complex products. A general method for developing performance indicators is presented. The concept of Products in Development is proposed, this making it possible to monitor how value is created during the development of a product. Both these models aim at complementing the currently used performance measurement system in order to support effective and efficient development of complex products.

    The method used in this research is mainly focused around the collection of qualitative data through a focused group interview, multiple case studies,and industrial reference-group seminars. A survey has also been used to complement the qualitative with quantitative data. The use of various research methods has made it possible to triangulate the data, thus strengthening the validity of the findings.

  • 186.
    Cederholm, Lars
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Pettersson, Niklas
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Stereo Vision System for an Autonomous Robotic Platform2011Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
  • 187.
    Chanmongkolpanich, Kittiya
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Panthong, Supasana
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    The Internationalization Process of Telenor: A Case Study of Telenor in Thailand2009Independent thesis Advanced level (degree of Master (One Year)), 40 poäng / 60 hpOppgave
    Abstract [en]

    This thesis is to describe the internationalization process of Telenor in terms of entry modes and management of control. While reading this thesis, readers will be acknowledged more about the appropriate process that Telenor applied to Thailand. Moreover, the suitable control to manage Telenor’s international operation in Thailand is also shown herewith.

  • 188.
    Charbachi, Peter
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Eklund, Linus
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Enoiu, Eduard Paul
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Can Pairwise Testing Perform Comparably to Manually Handcrafted Testing Carried Out by Industrial Engineers?2017Inngår i: Proceedings - 2017 IEEE International Conference on Software Quality, Reliability and Security Companion, QRS-C 2017, Institute of Electrical and Electronics Engineers Inc. , 2017, s. 92-99Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Testing is an important activity in engineering of industrial software. For such software, testing is usually performed manually by handcrafting test suites based on specific design techniques and domain-specific experience. To support developers in testing, different approaches for producing good test suites have been proposed. In the last couple of years combinatorial testing has been explored with the goal of automatically combining the input values of the software based on a certain strategy. Pairwise testing is a combinatorial technique used to generate test suites by varying the values of each pair of input parameters to a system until all possible combinations of those parameters are created. There is some evidence suggesting that these kinds of techniques are efficient and relatively good at detecting software faults. Unfortunately, there is little experimental evidence on the comparison of these combinatorial testing techniques with, what is perceived as, rigorous manually handcrafted testing. In this study we compare pairwise test suites with test suites created manually by engineers for 45 industrial programs. The test suites were evaluated in terms of fault detection, code coverage and number of tests. The results of this study show that pairwise testing, while useful for achieving high code coverage and fault detection for the majority of the programs, is almost as effective in terms of fault detection as manual testing. The results also suggest that pairwise testing is just as good as manual testing at fault detection for 64% of the programs.

  • 189.
    Chauhan, Muhammad Aufeef
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Evolvability Analysis Method for Open Source Software Systems2011Independent thesis Advanced level (degree of Master (One Year)), 30 poäng / 45 hpOppgave
    Abstract [en]

    Software systems evolve over the life span to accommodate changes in order to meet technical and business requirements. Evolution of open source software (OSS) is challenging because of involvement from a large number of independent teams and developers who make modifications in the systems according to their own requirements. It is required to evaluate these changes as these are being incorporated into the system against the long term evolvability objectives. This paper presents the analysis of the Hackystat, an OSS framework; against analyzability, changeability, extensibility, testability domain specific quality attributes. The analysis of the processes used during the development of the OSS systems is also discussed. On the basis of the analysis and the early research conducted to evaluate software evolvability, an evolvability analysis method for OSS evolution is presented in this report. Guidelines of the model suggest that the requirements identification and analysis, identification of the system components that are to be affected as a result of the change, identification and prioritization of the potential solutions, evaluation of the potential solutions with respect to evolvability characteristics, use of test driven development and automated build tools are the important steps that should be performed to evaluate system changes. Evolvability analysis model also suggests that the team which is responsible to for system overall architecture (project control group) should also evaluate changes submitted by different teams. A case study to modify a service oriented architecture bases system into software as a service cloud model following the guidelines of evolvability analysis model is also presented.

  • 190.
    Chauhan, Muhammad Aufeef
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Babar, M. A.
    IT University of Copenhagen.
    Migrating service-oriented system to cloud computing: An experience report2011Inngår i: Proceedings - 2011 IEEE 4th International Conference on Cloud Computing, CLOUD 2011, 2011, s. 404-411Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Cloud computing has gained significant attention of industry and academic sectors which are interested in adopting or experimenting with this technology. An increasing number of companies are expected to migrate their systems to cloud enabled infrastructures. However, there has not been much attention paid to provide sufficient process support. Since migration projects are likely to encounter several kinds of challenges, it is important to identify and share the process and logistical requirements of migration projects in order to build a body of knowledge of appropriate process, methods, and tools. This paper purports to contribute to the growing knowledge of how to migrate existing systems to cloud computing by reporting our effort aimed at migrating an Open Source Software (OSS) framework, Hackystat, to cloud computing. We report the main steps followed, the process and technical challenges faced, and some of the strategies that helped us to address those challenges. We expect the reported experiences can provide readers with useful insights into the process and technical aspects that should be considered when migrating existing software systems to cloud computing infrastructures. © 2011 IEEE.

  • 191.
    Chirumalla, Koteshwar
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Innovation och produktrealisering.
    Bengtsson, Marcus
    Mälardalens högskola, Akademin för innovation, design och teknik, Innovation och produktrealisering.
    Söderlund, Carina
    Mälardalens högskola, Akademin för innovation, design och teknik, Innovation och produktrealisering.
    Experience Reuse in Production Maintenance: Practices and Challenges2015Inngår i: 22nd International Annual EurOMA Conference EurOMA15, 2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The reuse of experiences gained in maintenance activities is important issue in maintenance management. Efficient experience reuse would improve next interventions, reduce the mistakes and potentially contribute to time and cost savings. However, few studies focus on how maintenance workforce reuses past experiences in the problem- solving phases of the maintenance work. The purpose of this study is therefore to examine the experience reuse process in production maintenance in order to identify reuse practices and its challenges. Based on a case study, this paper presents the observed work practices and its challenges for collecting and reusing experiences in production maintenance. Further, potential improvement suggestions are proposed to overcome these challenges.

  • 192.
    Ciambriello, Gianluigi
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    D'Amelio, Paolo
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Web Based AHP and CPC evaluation System2009Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Making a decision today is quite important, especially in companies, where the consequences can bring benefits or costs. Sometimes the decisions to be made are complex and we need to evaluate many criterions that can involve several factors. In those cases, it is not easy to have a good overview of all choices and for this reason it is important to have a system that helps us in making complex decisions, when it is not possible to evaluate all the alternatives manually. This thesis describes different algorithms and tools that can aid in the process of making decisions. Based on the review of existing tools a new web based application is proposed. The new tool, Decision Maker, uses both the full Analytical Hierarchical Process approach and Chainwise Paired Comparisons method to evaluate different alternatives.

  • 193.
    Cicchetti, Antonio
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Ciccozzi, Federico
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Leveque, Thomas
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Pierantonio, A.
    University of L'Aquila, Italy .
    On the concurrent versioning of metamodels and models: Challenges and possible solutions2011Inngår i: ACM International Conference Proceeding Series, 2011, 2011, s. 16-25Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Model-Driven Engineering aims at shifting the focus of software development from coding to modelling in order to reduce the complexity of realizing nowadays applications. In this respect, models are expected to evolve due to refinements, improvements, bug fixes, and so forth. Because of the same reasons, also modelling languages (i.e. metamodels) are expected to be changed, even though at a different speed if compared to models. The relevant corpus of research grown up in the latest years and dealing with both these problems considers them as separate events; however, in normal practice not all the models are migrated instantaneously due to a metamodel adaptation, rather the co-adaptation is required when commits are attempted from a local workspace to the model repository, which can demand for different management policies. This paper illustrates the challenges arising in coping with concurrent metamodel and model versioning. In particular, it details a set of desired behaviours among which the user would usually select the appropriate management for the scenario into consideration together with entailed problems. Moreover, the work proposes corresponding solutions and discusses open issues. 

  • 194.
    Cicchetti, Antonio
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Ciccozzi, Federico
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. Malardalen Univ, Sch Innovat Design & Engn IDT, Vasteras, Sweden..
    Pierantonio, Alfonso
    Univ Aquila, DISIM, Laquila, Italy..
    Multi-view approaches for software and system modelling: a systematic literature review2019Inngår i: Software and Systems Modeling, ISSN 1619-1366, E-ISSN 1619-1374, Vol. 18, nr 6, s. 3207-3233Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Over the years, a number of approaches have been proposed on the description of systems and software in terms of multiple views represented by models. This modelling branch, so-called multi-view software and system modelling, praises a differentiated and complex scientific body of knowledge. With this study, we aimed at identifying, classifying, and evaluating existing solutions for multi-view modelling of software and systems. To this end, we conducted a systematic literature review of the existing state of the art related to the topic. More specifically, we selected and analysed 40 research studies among over 8600 entries. We defined a taxonomy for characterising solutions for multi-view modelling and applied it to the selected studies. Lastly, we analysed and discussed the data extracted from the studies. From the analysed data, we made several observations, among which: (i) there is no uniformity nor agreement in the terminology when it comes to multi-view artefact types, (ii) multi-view approaches have not been evaluated in industrial settings and (iii) there is a lack of support for semantic consistency management and the community does not appear to consider this as a priority. The study results provide an exhaustive overview of the state of the art for multi-view software and systems modelling useful for both researchers and practitioners.

  • 195.
    Cicchetti, Antonio
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Di Ruscio, Davide
    Universit`a degli Studi dell’Aquila, Italy.
    Eramo, Romina
    Universit`a degli Studi dell’Aquila, Italy.
    Pierantonio, Alfonso
    Universit`a degli Studi dell’Aquila, Italy.
    JTL: a bidirectional and change propagating transformation language2011Inngår i: Lecture Notes in Computer Science, Vol 6563 / [ed] Malloy, B; Staab, S; VanDenBrand, M, Berlin: Springer, 2011, 6563, s. 183-202Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

     In Model Driven Engineering bidirectional transformations are considered a core ingredient for managing both the consistency and synchronization of two or more related models. However, while non-bijectivity in bidirectional transformations is considered relevant, current languages still lack of a common understanding of its semantic implications hampering their applicability in practice.

    In this paper, the Janus Transformation Language (JTL) is presented, a bidirectional model transformation language specifically designed to support non-bijective transformations and change propagation. In particular, the language propagates changes occurring in a model to one or more related models according to the specified transformation regardless of the transformation direction. Additionally, whenever manual modifications let a model be non reachable anymore by a transformation, the closest model which approximate the ideal source one is inferred. The language semantics is also presented and its expressivity and applicability are validated against a reference benchmark. JTL is embedded in a framework available on the Eclipse platform which aims to facilitate the use of the approach, especially in the definition of model transformations.

  • 196.
    Ciccozzi, Federico
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Explicit connection patterns (ECP) profile and semantics for modelling and generating explicit connections in complex UML composite structures2016Inngår i: Journal of Systems and Software, ISSN 0164-1212, E-ISSN 1873-1228, Vol. 121, s. 329-344Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Model-driven engineering can help in mitigating ever-growing complexity of modern software systems. In this sense, the Unified Modelling Language (UML) has gained a thick share in the market of modelling languages adopted in industry. Nevertheless, the generality of UML can make it hard to build complete code generators, simulators, model-based analysis or testing tools without setting variability in the semantics of the language. To tailor semantics variability the notion of semantic variation point has been introduced in UML 2.0. Our research focuses on the semantic variation point that leaves the rules for matching multiplicities of connected instances of components and ports undecided in UML composite structures. In order to allow model analysability, simulation and code generation, this semantics needs to be set. At the same time, leaving the burden of this task to the developers is often overwhelming for complex systems. In this paper we provide a solution for supporting modelling and automatic calculation and generation of explicit interconnections in complex UML composite structures. This is achieved by (i) defining a set of connection patterns, in terms of a UML profile, and related semantic rules for driving the calculation, (ii) providing a generation algorithm to calculate the explicit interconnections.

  • 197.
    Ciccozzi, Federico
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    From Models to Code and Back: A Round-trip Approach for Model-driven Engineering of Embedded Systems2014Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    The complexity of modern systems is continuously growing, thus demanding novel powerful development approaches.In this direction, model-driven and component-based software engineering have reached the status of promising paradigms for the development of complex systems. Moreover, in the embedded domain, their combination is believed to be helpful in handling the ever-increasing complexity of such systems.However, in order for them and their combination to definitively break through at industrial level, code generated from models through model transformations should preserve system properties modelled at design level.

    This research work focuses on aiding the preservation of system properties throughout the entire development process across different abstraction levels. Towards this goal, we provide the possibility of analysing and preserving system properties through a development chain constituted of three steps: (i) generation of code from system models, (ii) execution and analysis of generated code, and (iii) back-propagation of analysis results to system models.With the introduction of steps (ii) and (iii), properties that are hard to predict at modelling level are compared with runtime values and this consequently allows the developer to work exclusively at modelling level thus focusing on optimising system models with the help of those values.

  • 198.
    Ciccozzi, Federico
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Supporting Extra-Functional Properties Preservation in Model-Driven Engineering of Embedded Systems2011Rapport (Annet vitenskapelig)
    Abstract [en]

    In order for model-driven engineering to succeed, automated code generation from models through model transformations has to guarantee that extra-functional properties modelled at design level are preserved at code level. A full round-trip engineering approach could be needed in order to evaluate quality attributes of the embedded system by code execution monitoring/analysis tools and then provide backpropagation of the target code analysis results to modelling level. In this way, properties that can only be estimated statically are evaluated against runtime values and this consequently allows to optimize the design models for ensuring preservation of analysed extra-functional aspects. This paper presents an approach to support the whole round-trip process starting from the generation of source code for a target platform, passing through the monitoring of selected system quality attributes at code level, and nishing with the back-propagation of measured values to modelling level. The technique is validated against an industrial casestudy in the telecommunications applicative domain.

  • 199.
    Ciccozzi, Federico
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Toward Preservation of Extra-Functional Properties for Model-Driven Component-Based Software Engineering of Embedded Systems2012Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Model-driven and component-based software engineering have been widely recognized as promising paradigms for development of a wide range of systems. Moreover, in the embedded real-time domain, their combination is believed to be helpful in handling the ever-increasing complexity of such systems design.However, in order for these paradigms and their combination to definitely break through at an industrial level for development of embedded real-time systems, both functional and extra-functional properties need to be addressed at each level of abstraction.

    This research focuses on the preservation of extra-functional properties. More specifically, the aim is to provide support for easing such preservation throughout the entire development process at different abstraction levels.The main outcome of the research work is a round-trip engineering approach aiding the preservation of extra-functional properties by providing code generators, supporting monitoring and analysis of code execution, and then enabling back-propagation of the results to modelling level. In this way, properties that can only be roughly estimated statically are evaluated against runtime values and this consequently allows to optimize the design models for ensuring preservation of analysed extra-functional properties.

    Moreover, a solution for managing evolution of computational context in which extra-functional properties are defined by means of validity analysis is provided. Such solution introduces a new language for the description of the computational context in which a given property is provided and/or computed by some analysis, enables detection of changes performed to the context description, and analyses the possible impacts on the extra-functional property values based on a precise representation of differences between previous and current version of the model.

  • 200.
    Ciccozzi, Federico
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Corcoran, Diarmuid
    Ericsson AB, Kista, Sweden.
    Seceleanu, Tiberiu
    ABB Corporate Research, Vasteras, Sweden.
    Scholle, Detlef
    Alten Sverige AB, Sweden.
    SMARTCore: Boosting Model-Driven Engineering of Embedded Systems for Multicore2015Inngår i: Proceedings - 12th International Conference on Information Technology: New Generations, ITNG 2015, 2015, Vol. Article number 7113454, s. 89-94Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Thanks to continuous advances in both software and hardware technologies the power of modern embedded systems is ever increasing along with their complexity. Among the others, Model-Driven Engineering has grown consideration for mitigating this complexity through its ability to shift the focus of the development from hand-written code to models from which correct-by-construction implementation is automatically generated. However, the path towards correctness-by-construction is often twisted by the inability of current MDE approaches to preserve certain extra-functional properties such as CPU and memory usage, execution time and power consumption. With SMARTCore we address open challenges, described in this paper together with an overview of possible solutions, in modelling, generating code from models, and exploiting back-propagated extra-functional properties observed at runtime for deployment optimisation of embedded systems on multicore. SMARTCore brings together world leading competence in software engineering, model-driven engineering for embedded systems (Mälardalen University), and market leading expertise in the development of these systems in different business areas (ABB Corporate Research, Ericsson AB, Alten Sweden AB).

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