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  • 1.
    Alklind Taylor, Anna-Sofia
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Facilitation matters: A framework for instructor-led serious gaming2014Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis explores the use of serious games from an instructor perspective. More specifically, it aims to study the roles of instructors and how they can be facilitated within an instructor-led game-based training environment. Research within the field of serious games has mostly focused on the learners' perspective, but little attention has been paid to what the instructors do and what challenges that entails. In this thesis, I argue that serious games, as artefacts used for learning and training, cannot fully replace the instructors' tasks, but must rather be designed to facilitate the various activities of the instructors. Thus, instructors form an important target audience in serious game development – not just as subject matter experts, but also as users and players of the game – with a different set of needs than the learners. Moreover, serious gaming (the actualisation of a serious game) involves more than in-game activities, it also involves actions and events that occur off-game. These activities must also be considered when designing and utilising games for learning and training.

    Using a qualitative approach, instructor-led serious gaming has been explored from a range of contexts, from rehabilitation to incident commander training and military training. Several different instructor roles have been identified and characterised, including in-game facilitator, puckster, debriefer, technical support and subject matter expert. Based on empirical and theoretical material, a framework for instructor-led serious gaming has been developed. It involves best practices in different phases of game-based training, such as scenario authoring, coaching-by-gaming, assessing in-game and off-game performance, giving feedback, and conducting a debriefing or after-action review. Furthermore, specific needs and challenges for instructors have been identified and reformulated into guidelines for instructor-led serious gaming. The guidelines highlight the importance of usability and visualisation, as well as the need for carefully designed support tools for instructors' situation awareness, assessment and debriefing. Lastly, a number of success factors pertaining to both the development and actualisation of serious games are presented. Since serious games aim to be both productive and engaging, it is advantageous to work with interdisciplinary teams when developing serious games. This includes subject matter experts well versed in serious gaming practices. Furthermore, a successful serious game should adhere to sound pedagogical theories, be easy to use and maintain, and include system support for instructors' tasks. Successful serious gaming practices also involve having an organisational culture that fosters knowledge sharing among practitioners.

  • 2.
    Amouzgar, Kaveh
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Metamodel Based Multi-Objective Optimization with Finite-Element Applications2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    As a result of the increase in accessibility of computational resources and the increase of computer power during the last two decades, designers are able to create computer models to simulate the behavior of complex products. To address global competitiveness, companies are forced to optimize the design of their products and production processes. Optimizing the design and production very often need several runs of computationally expensive simulation models. Therefore, integrating metamodels, as an efficient and sufficiently accurate approximate of the simulation model, with optimization algorithms is necessary. Furthermore, in most of engineering problems, more than one objective function has to be optimized, leading to multi-objective optimization(MOO). However, the urge to employ metamodels in MOO, i.e., metamodel based MOO (MB-MOO), is more substantial.Radial basis functions (RBF) is one of the most popular metamodeling methods. In this thesis, a new approach to constructing RBF with the bias to beset a priori by using the normal equation is proposed. The performance of the suggested approach is compared to the classic RBF and four other well-known metamodeling methods, in terms of accuracy, efficiency and, most importantly, suitability for integration with MOO evolutionary algorithms. It has been found that the proposed approach is accurate in most of the test functions, and it was the fastest compared to other methods. Additionally, the new approach is the most suitable method for MB-MOO, when integrated with evolutionary algorithms. The proposed approach is integrated with the strength Pareto evolutionary algorithm (SPEA2) and applied to two real-world engineering problems: MB-MOO of the disk brake system of a heavy truck, and the metal cutting process in a turning operation. Thereafter, the Pareto-optimal fronts are obtained and the results are presented. The MB-MOO in both case studies has been found to be an efficient and effective method. To validate the results of the latter MB-MOO case study, a framework for automated finite element (FE) simulation based MOO (SB-MOO) of machining processes is developed and presented by applying it to the same metal cutting process in a turning operation. It has been proved that the framework is effective in achieving the MOO of machining processes based on actual FE simulations.

  • 3.
    Andersson, Martin
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    A bilevel approach to parameter tuning of optimization algorithms using evolutionary computing: Understanding optimization algorithms through optimization2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Most optimization problems found in the real world cannot be solved using analytical methods. For these types of difficult optimization problems, an alternative approach is needed. Metaheuristics are a category of optimization algorithms that do not guarantee that an optimal solution will be found, but instead search for the best solutions using some general heuristics. Metaheuristics have been shown to be effective at finding “good-enough” solutions to a wide variety of difficult problems. Most metaheuristics involve control parameters that can be used to modify how the heuristics perform its search. This is necessary because different problems may require different search strategies to be solved effectively. The control parameters allow for the optimization algorithm to be adapted to the problem at hand. It is, however, difficult to predict what the optimal control parameters are for any given problem. The problem of finding these optimal control parameter values is known as parameter tuning and is the main topic of this thesis. This thesis uses a bilevel optimization approach to solve parameter tuning problems. In this approach, the parameter tuning problem itself is formulated as an optimization problem and solved with an optimization algorithm. The parameter tuning problem formulated as a bilevel optimization problem is challenging because of nonlinear objective functions, interacting variables, multiple local optima, and noise. However, it is in precisely this kind of difficult optimization problem that evolutionary algorithms, which are a subclass of metaheuristics, have been shown to be effective. That is the motivation for using evolutionary algorithms for the upper-level optimization (i.e. tuning algorithm) of the bilevel optimization approach. Solving the parameter tuning problem using a bilevel optimization approach is also computationally expensive, since a complete optimization run has to be completed for every evaluation of a set of control parameter values. It is therefore important that the tuning algorithm be as efficient as possible, so that the parameter tuning problem can be solved to a satisfactory level with relatively few evaluations. Even so, bilevel optimization experiments can take a long time to run on a single computer. There is, however, considerable parallelization potential in the bilevel optimization approach, since many of the optimizations are independent of one another. This thesis has three primary aims: first, to present a bilevel optimization framework and software architecture for parallel parameter tuning; second, to use this framework and software architecture to evaluate and configure evolutionary algorithms as tuners and compare them with other parameter tuning methods; and, finally, to use parameter tuning experiments to gain new insights into and understanding of how optimization algorithms work and how they can used be to their maximum potential. The proposed framework and software architecture have been implemented and deployed in more than one hundred computers running many thousands of parameter tuning experiments for many millions of optimizations. This illustrates that this design and implementation approach can handle large parameter tuning experiments. Two types of evolutionary algorithms, i.e. differential evolution (DE) and a genetic algorithm (GA), have been evaluated as tuners against the parameter tuning algorithm irace. The as pects of algorithm configuration and noise handling for DE and the GA as related to the parameter tuning problem were also investigated. The results indicate that dynamic resampling strategies outperform static resampling strategies. It was also shown that the GA needs an explicit exploration and exploitation strategy in order not become stuck in local optima. The comparison with irace shows that both DE and the GA can significantly outperform it in a variety of different tuning problems.

  • 4.
    Aslam, Tehseen
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Analysis of manufacturing supply chains using system dynamics and multi-objective optimization2013Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Supply chains are in general complex networks composed of autonomous entities whereby multiple performance measures in different levels, which in most cases are in conflict with each other, have to be taken into account. Hence, due to the multiple performance measures, supply chain decision making is much more complex than treating it as a single objective optimization problem. Thus, the aim of the doctoral thesis is to address the supply chain optimization problem within a truly Pareto-based multi-objective context and utilize knowledge extraction techniques to extract valuable and useful information from the Pareto optimal solutions. By knowledge extraction, it means to detect hidden interrelationships between the Pareto solutions, identify common properties and characteristics of the Pareto solutions as well as discover concealed structures in the Pareto optimal data set in order to support managers in their decision making. This aim is addressed through the SBO-framework where the simulation methodology is based on system dynamics (SD) and the optimization utilizes multi-objective optimization (MOO). In order to connect the SD and MOO software, this doctoral thesis introduced a novel SD and MOO interface application which allow the modeling and optimization applications to interact. Additionally, this thesis work also presents a novel SD-MOO methodology that addresses the issue of curse off dimensionality in MOO for higher dimensional problems and with the aim to execute supply chain SD-MOO in a computationally cost efficient way, in terms of convergence, solution intensification and accuracy of obtaining the Pareto-optimal front for complex supply chain problems. In order to detect evident and hidden structures, characteristics and properties of the Pareto-optimal solutions, this work utilizes Parallel Coordinates, Clustering and Innovization, which are three different types of tools for post-optimal analysis and facilitators of discovering and retrieving knowledge from the Pareto-optimal set. The developed SD-MOO interface and methodology are then verified and validated through two academic case studies and a real-world industrial application case study. While not all the insights generated in these application studies can be generalized for other supply-chain systems, the analysis results provide strong indications that the methodology and techniques introduced in this thesis are capable to generate knowledge to support academic SCM research and real-world SCM decision making, which to our knowledge cannot be performed by other methods.

  • 5.
    Berg Marklund, Björn
    University of Skövde, The Informatics Research Centre. University of Skövde, School of Humanities and Informatics.
    Games in Formal Educational Settings: Obstacles for the development and use of learning games2013Licentiate thesis, monograph (Other academic)
    Abstract [en]

    From the perspective of educators, games are viewed as a medium in which the younger generation both thrive and excel. Students navigate game environments with ease and regularly solve problems, engage in advanced collaborative efforts, and communicate complex concepts and strategies to one another during their private gaming sessions at home. Games invite the player to form an understanding of intricate systems and mechanics based on participation and experimentation rather than mere observation, and on these merits games are often prophesized as a medium that will significantly change the face of education as we know it. However, while teacher interest in using games is increasing, wide-spread and successful examples of games being implemented in formal educational contexts (e.g. schools and university courses) remain rare.

    This thesis aims to examine why this is the case and identifies some of the more prevalent obstacles educators and developers both face when embarking on learning game projects as users and creators. In order to examine the situation from both of these perspectives, the research takes a mixed-method approach that entails extensive literature studies coupled with several studies with both educators and developers. Interviews were conducted in order to investigate attitudes and experiences, and more direct researcher participation and case studies were used to examine the processes of implementing and developing learning games as they were carried out. The studied cases and literature have revealed obstacles that indicate that “traditional” entertainment game development is incommensurable with learning game development, and that the use of games in formal educational settings introduces heavy demands on the recipient organization’s infrastructure, culture, and working processes.

    The conclusion of this research is that learning games embody a unique mixture of utility and game experience, and the formal context which they are to be used in significantly influence the process of developing and using them. Learning games can’t be understood if they’re solely seen as a teaching utility or solely as a game experience and to make them viable both educators and developers need to change their internal processes, their own perceptions of games and teaching, as well as the way they collaborate and communicate with each other. There are also several obstacles that are outside individual institutions and developers’ control, for example the practicalities of the economic constraints that both developers and educators work under that put the sustainability of pursuing learning games for formal education as a business into question. However, the continuous incremental improvements on the infrastructure of educational institutions (e.g. availability of technology and teachers’ familiarity with technology) can likely alleviate many of the obstacles currently inhibiting the impact learning games can potentially have in formal education.

  • 6.
    Berg Marklund, Björn
    University of Skövde, The Informatics Research Centre. University of Skövde, School of Informatics.
    Unpacking Digital Game-Based Learning: The complexities of developing and using educational games2015Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Digital game-based learning has traditionally been examined from an ‘artefact-centric’ perspective that focuses on understanding how game design and principles of learning are, or can be, intertwined. These types of examinations have resulted in many descriptions of games’ educational potential, which has subsequently led to many types of arguments for why games should be used more extensively in formal education. However, comparatively little research has been done to understand the educational settings in which many game-based learning processes and educational games are intended to be applied. The relative lack of research on formal education settings has resulted in a scenario where the educational potential of games is well detailed through theory and understood independently of their actual contexts of use, while successful examples of games “making good” on their promises as educational tools remain rare.

    This thesis explores and describes the various challenges that the realities of formal education present to developers and educators who attempt to work with educational games. In order to examine the multi-faceted nature of educational games, the research has used a qualitative mixed-method approach that entails extensive literature reviews coupled with several case studies that involve educators, students, and developers. Interviews were conducted in order to investigate these actors’ various attitudes towards, and experiences of, educational games and game-based learning. In addition, more in-depth researcher participation methods were employed during case studies to examine the processes involved in developing, integrating, and using educational games in formal settings. The research revealed obstacles which indicate that processes associated with “traditional” game development are incommensurable with educational game development. Furthermore, the research demonstrates that the use of games in formal education introduces heavy demands on the recipient organisations’ infrastructures, cultures, and working processes. So, while games created for “formal” and “informal” use are superficially similar, the different contexts in which they are used make them distinctly different from one another. 

    The conclusion of this research is that educational games manifest a unique mixture of utility, gameplay, and context-dependent meaning-making activities. Educational games cannot be understood if they are only seen as a teaching utility or only as a game experience. To make educational games viable, both educators and developers need to alter their working processes, their own perceptions of games and teaching, as well as the way they collaborate and communicate with each other and other actors within the educational game ‘system’. The thesis thus argues that a more systems-oriented understanding of educational games, where the game artefact is not treated separately from the context of use, is necessary for both research and practice in the field to progress. To contribute to such an understanding of educational games, a comprehensive model (dubbed the Utility, Gameplay, and Meaning Model) of the ‘educational game system’ is presented, as well as a series of recommendations and considerations to help developers and educators navigate the complex processes involved in creating and using educational games.

  • 7.
    Bernedixen, Jacob
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Automated Bottleneck Analysis of Production Systems: Increasing the applicability of simulation-based multi-objective optimization for bottleneck analysis within industry2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Manufacturing companies constantly need to explore new management strategies and new methods to increase the efficiency of their production systems and retain their competitiveness. It is of paramount importance to develop new bottleneck analysis methods that can identify the factors that impede the overall performance of their productionsystems so that the optimal improvement actions can be performed. Many of the bottleneck-related research methods developed in the last two decades are aimed mainly at detecting bottlenecks. Due to their sole reliance on historical data and lackof any predictive capability, they are less useful for evaluating the effect of bottleneck improvements.

    There is an urgent need for an efficient and accurate method of pinpointing bottlenecks, identifying the correct improvement actions and the order in which these should be carried out, and evaluating their effects on the overall system performance. SCORE (simulation-based constraint removal) is a novel method that uses simulation based multi-objective optimization to analyze bottlenecks. By innovatively formulating bottleneck analysis as a multi-objective optimization problem and using simulation to evaluate the effects of various combinations of improvements, all attainable, maximum throughput levels of the production system can be sought through a single optimization run. Additionally, post-optimality frequency analysis of the Pareto-optimal solutions can generate a rank order of the attributes of the resources required to achieve the target throughput levels. However, in its original compilation, SCORE has a very high computational cost, especially when the simulation model is complex with a large number of decision variables. Some tedious manual setup of the simulation based optimization is also needed, which restricts its applicability within industry, despite its huge potential. Furthermore, the accuracy of SCORE in terms of convergence in optimization theory and correctness of identifying the optimal improvement actions has not been evaluated scientifically.

    Building on previous SCORE research, the aim of this work is to develop an effective method of automated, accurate bottleneck identification and improvement analysis that can be applied in industry.

    The contributions of this thesis work include:

    (1) implementation of a versatile representation in terms of multiple-choice set variables and a corresponding constraint repair strategy into evolutionary multi-objective optimization algorithms;

    (2) introduction of a novel technique that combines variable screening enabled initializationof population and variable-wise genetic operators to support a more efficient search process;

    (3) development of an automated setup for SCORE to avoid the tedious manual creation of optimization variables and objectives;

    (4) the use of ranking distance metrics to quantify and visualize the convergence and accuracy of the bottleneck ranking generated by SCORE.

    All these contributions have been demonstrated and evaluated through extensive experiments on scalable benchmark simulation models as well as several large-scale simulation models for real-world improvement projects in the automotive industry.

    The promising results have proved that, when augmented with the techniques proposed in this thesis, the SCORE method can offer real benefits to manufacturing companies by optimizing their production systems.

  • 8.
    Bevilacqua, Fernando
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Game-calibrated and user-tailored remote detection of emotions: A non-intrusive, multifactorial camera-based approach for detecting stress and boredom of players in games2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Questionnaires and physiological measurements are the most common approach used to obtain data for emotion estimation in the field of human-computer interaction (HCI) and games research. Both approaches interfere with the natural behavior of users. Initiatives based on computer vision and the remote extraction of user signals for emotion estimation exist, however they are limited. Experiments of such initiatives have been performed under extremely controlled situations with few game-related stimuli. Users had a passive role with limited possibilities for interaction or emotional involvement, instead of game-based emotion stimuli, where users take an active role in the process, making decisions and directly interacting with the media. Previous works also focus on predictive models based on a group perspective. As a consequence, a model is usually trained from the data of several users, which in practice describes the average behavior of the group, excluding or diluting key individualities of each user. In that light, there is a lack of initiatives focusing on non-obtrusive, user-tailored emotion detection models, in particular regarding stress and boredom, within the context of games research that is based on emotion data generated from game stimuli. This research aims to fill that gap, providing the HCI and the games research community with an emotion detection process that can be used to remotely study user's emotions in a non-obtrusive way within the context of games.

    The main knowledge contribution of this research is a novel process for emotion detection that is non-obtrusive, user-tailored and game-based. It uses remotely acquired signals, namely, heart rate (HR) and facial actions (FA), to create a user-tailored model, i.e. trained neural network, able to detect the emotional states of boredom and stress of a given subject. The process is automated and relies on computer vision and remote photoplethysmography (rPPG) to acquire user signals, so that specialized equipment, e.g. HR sensors, is not required and only an ordinary camera is needed. The approach comprises two phases: training (or calibration) and testing. In the training phase, a model is trained using a user-tailored approach, i.e. data from a given subject playing calibration games is used to create a model for that given subject. Calibration games are a novel emotion elicitation material introduced by this research. These games are carefully designed to present a difficulty level that constantly and linearly progresses over time without a pre-defined stopping point. They induce emotional states of boredom and stress, accounting for particularities at an individual level. Finally, the testing phase occurs in a game session involving a subject playing any ordinary, non-calibration game, e.g. Super Mario. During the testing phase, the subject's signals are remotely acquired and fed into the model previously trained for that particular subject. The model subsequently outputs the estimated emotional state of that given subject for that particular testing game.

    The method for emotion detection proposed in this thesis has been conceived on the basis of established theories and it has been carefully evaluated in experimental setups. Results show a statistical significance classification of emotional states with a mean accuracy of 61.6\%. Finally, this thesis presents a series of systematic evaluations conducted in order to understand the relation between psychophysiological signals and emotions. Facial behavior and physiological signals, i.e. HR, are analyzed and discussed as indicators of emotional states. This research reveals that individualities can be detected regarding facial activity, e.g. an increased number of facial actions during the stressful part of games. Regarding physiological signals, findings are aligned with and reinforce previous research that indicates higher HR mean during stressful situations in a gaming context. Results also suggest that changes in HR during gaming sessions are a promising indicator of stress. The method for the remote detection of emotions, presented in this thesis, is feasible, but does contain limitations. Nevertheless, it is a solid initiative to move away from questionnaires and physical sensors into a non-obtrusive, remote-based solution for the evaluation of user emotions.

  • 9.
    Brodin, Martin
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre. Actea Consulting AB.
    Mobile Device Strategy: A management framework for securing company information assets on mobile devices2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The problem addressed by this research is a demand for increased flexibility in access to organisational information, driven by the increasing popularity of mobile devices. Employees increasingly bring private devices to work (Bring Your Own Device, BYOD) or use work devices for private purposes (Choose Your Own Device, CYOD). This puts managers in a difficult position, since they want the benefits of mobility, without exposing organisational data to further risk. The research focuses on management (particularly information security management) issues in the design and implementation of strategies for mobile devices.  There are two objectives. The first is to identify existing information security management strategies for mobile and dual-use devices. The second is to develop a framework for analysing, evaluating and implementing a mobile device strategy.

    The overall research strategy is inspired by Design Science; where the mission is to develop an artefact, in this case a framework, which will help to solve a practical problem. Methods include literature review, theoretical development, and the collection and analysis of qualitative data through interviews with executives. The main result of this work is the framework, which deals with the complete process, including analysis, design and implementation of a mobile device management strategy. It helps researchers to understand necessary steps in analysing phenomenon like BYOD and gives practitioners guidance in which analyses to conduct when working on strategies for mobile devices. The framework was developed primarily through theoretical work (with inspiration from the mobile security and strategic management literature, and the ISO/IEC 27000 standard), and evaluated and refined through the empirical studies. The results include twelve management issues, a research agenda, argumentation for CYOD and, guidance for researchers and practitioners.

  • 10.
    Egaña Iztueta, Lander
    et al.
    University of Skövde, School of Engineering Science.
    Roda Martínez, Javier
    University of Skövde, School of Engineering Science.
    Function Block Algorithms for Adaptive Robotic Control2014Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this project is the creation of an adaptive Function Block control system, and the implementation of Artificial Intelligence integrated within the Function Block control system, using IEC 61499 standard to control an ABB 6-axis virtual robot, simulated in the software RobotStudio. To develop these objectives, we studied a lot of necessary concepts and how to use three different softwares. To learn how to use the softwares, some tests were carried out. RobotStudio is a program developed by ABB Robotics Company where an ABB robot and a station are simulated. There, we designed and created a virtual assembly cell with the virtual IRB140 robot and the necessary pieces to simulate the system. To control the robot and the direct access to the different tools of RobotStudio, it is necessary to use an application programming interface (API) developed by ABB Robotics Company. C sharp (C#) language is used to program using the API, but this language is not supported by the Function Block programming software nxtStudio. Because of this, we used VisualStudio software. In this software, we use the API libraries to start and stop the robot and load a RAPID file in the controller. In a RAPID file the instructions that the robot must follow are written. So, we had to learn about how to program in C# language and how to use VisualStudio software. Also, to learn about IEC 61499 standard it was necessary to read some books. This standard determines how an application should be programmed through function blocks. A function block is a unit of program with a certain functionality which contains data and variables that can be manipulated in the same function block by several algorithms. To program in this standard we learnt how to use nxtStudio software, consuming a lot of time because the program is quite complex and it is not much used in the industrial world yet. Some tests were performed to learn different programing skills in this standard, such as how to use UDP communication protocol and how to program interfaces. Learning UDP communication was really useful because it is necessary for communication between nxtStudio and other programs, and also learning how to use interfaces to let the user access the program. Once we had learnt about how to use and program the different softwares and languages, we began to program the project. Then, we had some troubles with nxtStudio because strings longer than fourteen characters cannot be used here. So, a motion alarm was developed in VisualStudio program. And another important limitation of nxtStudio is that C++ language cannot be used. Therefore, the creation of an Artificial Intelligence system was not possible. So, we created a Function Block control system. This system is a logistical system realised through loops, conditions and counters. All this makes the robot more adaptive. As the AI could not be carried out because of the different limitations, we theoretically designed the AI system. It will be possible to implement the AI when the limitations and the problems are solved.

  • 11.
    Ericson, Stefan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Vision-Based Perception for Localization of Autonomous Agricultural Robots2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis Stefan investigates how cameras can be used for localization of an agricultural mobile robot. He focuses on relative measurement that can be used to determine where a weeding tool is operating relative a weed detection sensor. It incorporates downward-facing perspective cameras, forward-facing perspective cameras and omnidirectional cameras. Stefan shows how the camera’s ego-motion can be estimated to obtain not only the position in 3D but also the orientation. He also shows how line structures in the field can be used to navigate a robot along the rows.

  • 12.
    Fornlöf, Veronica
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. GKN Aerospace Engine Systems.
    Improved remaining useful life estimations for on-condition parts in aircraft engines2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis focuses on obtaining better estimates of remaining life for on-condition (OC) parts in aircraft engines. Aircraft engine components are commonly classified into three categories, life-limited parts (LLP), OC-parts and consumables. Engine maintenance typi-cally accounts for 10% to 20% of aircraft-related operating cost. Current methods to esti-mate remaining life for OC parts have been found insufficient and this thesis aims to devel-op a method that obtains better life estimates of OC part. Improved life estimates are es-sential to facilitate more reliable maintenance plans and lower maintenance costs. In the thesis, OC parts that need a better life estimates are identified and suitable prognosis methodologies for estimating the remaining life are presented.

    Three papers are appended to the thesis. The first paper lays out the main principles of air-craft engine maintenance and identifies the potential for improving maintenance planning by improving the remaining life estimation for the OC parts. The paper concludes that re-search is needed to find better estimates so that the right amount of maintenance is per-formed at each maintenance occasion.

    The second paper describes the aircraft and its engine from a system of system perspective. The aim of the paper is to show that no system is stronger than its weakest part and that there is a potential to increase the availability and readiness of the complete system, the aircraft engine, by introducing better life estimates for OC parts. Furthermore, a review of all engine parts, no matter if they are life-limited or on-condition, which needs to be incor-porated in a replacement model for maintenance optimization, is given. The paper con-cludes that the reliability of the complete aircraft engine would be increased if better life estimates are presented also for the OC parts.

    The third paper includes an evolved analysis of the subject and the analysis moves deeper in to a subsystem/module of the engine, the low pressure turbine. The specific subsys-tem/module is further analyzed to show the potential of increased reliability for the subsys-tem/module and the complete system, the aircraft engine, if better life estimates for the OC parts are obtained. Methods on how to estimate remaining life is discussed in this paper. It is stated that life estimates can be based on visual inspections, available testing methods (e.g. non destructive testing ) or new techniques that may be need to be developed based on remaining useful life estimations. To estimate the remaining life for the OC parts well es-tablished prognostic techniques such as physic-based, data-driven, symbolic, hybrid, or context awareness approaches that combine contextual/situation information awareness will be considered.

  • 13.
    Goienetxea Uriarte, Ainhoa
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Bringing Together Lean, Simulation and Optimization: Defining a framework to support decision-making in system design and improvement2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The rapid changes in the market including globalization, the requirement for personalizedproducts and services by the customers, shorter product life-cycles, the exponential growthof technological advances, and the demographical changes, will demand organizations toeffectively improve and design their systems in order to survive. This is the actual paradigmcharacterizing the industrial and service sectors. This scenario presents a considerablechallenge to decision makers who will need to decide about how to design and improve amore than ever complex system without compromising the quality of the decision taken.Lean, being a widely applied management philosophy with very powerful principles, itsmethods and tools are static in nature and have some limitations when it comes to the designand improvement of complex and dynamic systems. Some authors have proposed thecombined use of simulation with Lean in order to overcome these limitations. Furthermore,optimization and post-optimization tools coupled to simulation, provide knowledge aboutoptimal or nearly optimal system configurations to choose from. However, even if Leanprinciples, methods and tools, as well as simulation and optimization, pursue the objectiveof supporting organizations regarding system design and improvement, a bilateral approachfor their combination and its benefits have barely been addressed in the literature.Many studies focus only on how specific Lean tools and simulation can be combined, treatingLean purely as a toolbox and not considering how Lean can support the simulation process.The aim of this research is to address this knowledge gap by analyzing the mutualbenefits and presenting a framework for combining Lean, simulation and optimization tobetter support decision makers in system design and improvement where the limitationsof Lean tools and simulation are overcome by their combination. This framework includesa conceptual framework explaining the relationships between the Lean philosophy, methodsand tools with simulation and optimization; the purposes for this combination and stepby step processes to achieve these purposes; the identification of the roles involved in eachprocess; a maturity model providing guidelines on how to implement the framework; existingbarriers for the implementation; and ethical considerations to take into account. Anindustrial handbook has also been written which explains how to deploy the framework.The research has been conducted in three main stages including an analysis of the literatureand the real-world needs, the definition and formulation of the framework, and finally, itsevaluation in real-world projects and with subject matter experts. The main contributionof this research is the reflection provided on the bilateral benefits of the combination, aswell as the defined and evaluated framework, which will support decision makers take qualitydecisions in system design and improvement even in complex scenarios.

  • 14.
    Gudfinnsson, Kristens
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Towards facilitating BI adoption in small and medium sized manufacturing companies2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This work concerns how to support Small and Medium sized Manufacturing Enterprises(SMMEs) with their Business Intelligence (BI) adoption, with the long term aim of supporting them in making better use of their BI investments and becoming (more)data-driven in their decision-making processes. Current BI research focuses primarily on larger enterprises, despite the fact that the majority of businesses are small or mediumsized. Therefore, this research focuses on the body of knowledge concerning how SMMEs can be more intelligent about their business, and better adopt BI to improve decision-making. Accordingly, the overall research aim is to create an artefact that can support SMMEs to facilitate BI adoption. An understanding of the current situation of BI adoption within SMMEs needs to be attained to achieve this, which is the focus for the first research question: What is the current state-of-practice in relation to BI adoption in SMMEs? The research question adds to current knowledge on how SMMEs are taking advantage of BI and highlights which functions within companies are currently supported by BI. Research question two identifies the main challenges that SMMEs are facing in this context: What are the main challenges for BI adoption in SMMEs? This question adds to knowledge regarding some of the barriers and hindrances SMMEs face in BI adoption. Finally, the third research question addresses how SMMEs can address the challenges in successfully adopting BI: How can the main challenges be addressed? The research question is answered by providing descriptions of work in four participating companies addressing different types of problems. Many of the challenges from literature (and from empirical data from the participating companies) regarding BI adoption are met. The outcome adds to the literature a hands-on approach for companies to address chosen problems in their settings, and addressing many of the factors previously found in the BI adoption literature. An action design research (ADR) method is used to fulfill the overall research aim. The ADR method is used to guide the development of a framework artefact based on previousliterature, and on empirical findings from working with participating companies. Theoretical background was obtained through a literature review of BI adoption and usage. Empirical material was gathered both through interviews and by reviewing documents from the companies. The work that was done in participating companies was supported by previous literature in several ways: through the use of an elicitation activity, through the core concepts of BI, and by focusing on categories presented in a BI maturity model. The principal contribution of the research is in the form of a framework: the Business Intelligence Facilitation Framework (BIFF), which includes four phases. All phases contain activities that support companies in addressing BI adoption challenges from the literature and empirical data, in order to achieve the overall research aim. This research contributes both to research and practice. From a research point of view, the framework provides a way to address many of the factors previously identified in literature that need to be in place to increase the likelihood of successful BI adoption. From a practice perspective, the framework supports practitioners offering guidance in how to improve their BI adoption, providing activities for them to take, and guidance in how to carry out the activities.

  • 15.
    Hellberg, Patrik
    et al.
    University of Skövde, School of Engineering Science.
    Lindberg, Henrik
    University of Skövde, School of Engineering Science.
    Ställtidsförbättring på Cejn AB: SMED arbete i maskiner som bearbetar rostfritt material2015Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Företaget Cejn AB har idag svårt att konkurrera prismässigt på marknaden när det gäller vissa rostfria detaljer. Ett led i att minska kostnaderna för att producera artiklarna är önskemålet från företagets sida att se efter om det går att genomföra en ställtidsreducering på maskincellen, se bilaga 5, som tillverkar rostfritt. Företaget har även önskemål om att en checklista ska tas fram för hur ställarbetet ska gå till i cellen, för om möjligt standardisera arbetet. Skiftgången i cellen är idag tvåskift och maskinerna är bemannade med en operatör per maskin och skift. Nulägesanalysen, som gjordes i början av projektet, visar att den genomsnittliga ställtiden idag är på ca 18 % av planerad produktionstid.

    Önskad arbetsmetod från företagets sida var SMED (Singel Minute Exchange of Die), metoden myntades av Shiego Shingo som kom fram till att ett ställ, tiden det tar att byta produktion i en maskin av en produkt till en annan, bör kunna ske på under tio minuter. Metoden bygger på att förvandla inre ställ, arbete som pågår när maskinen står still, till yttre ställ, arbete som pågår när maskinen går. Endast de moment som måste göras när maskinen står still ska vara med i det inre stället. För att mäta den effekt SMED-arbetet medför och för att se hur lång tid som varje moment tar användes en tidsstudie. Valet föll på att använda en kontinuerlig klocka under tidtagningen. Tidsstudiedokumentet som användes för att notera tiderna i var framtaget med ursprung i de inledande observationerna. Då Cejn AB har Lean som produktionsfilosofi har ett antal verktyg inom området använts under arbetet. Övergripande arbetsmetod för arbetet har varit PDCA (Plan, Do, Check, Act), där varje mindre moment i arbetet har delats ned i mindre PDCA-cykler.

    Utifrån den inledande tidsstudien beräknades ett teoretiskt resultat fram, det visar på att bara genom att förändra den ordning som operatören utför arbetsmomenten i går det att minska ställtiden med ca 20 %. För att verifiera det resultatet och för att testa den checklista som var framtagen gjordes en pilotstudie. Den visar på att förändringen är ca 11 %, vilket beror på att de ställ som observerades var krångligare och svårare än de som den inledande studien mätte. Ovanan med att arbeta utefter det nya arbetssättet för operatörerna är även det en bidragande orsak till att det är en diskrepans mellan teoretiskt och verkligt utfall. Under pilotstudien testades även den ställåda som var framtagen i projektet, vilket mottogs bra av operatörerna. Resultatet från pilotstudien visar att ställådan har effekt på momentet med att montera verktyg. Effekten är att tiden minskar med ca 8 % av att den inre ställtiden på det momentet.

    De av Cejn AB satta målen har uppnåtts då ställtidsreducering kan påvisas och checklistor har tagits fram. Det nya arbetssättet kan standardiseras av företaget.

  • 16.
    Holgersson, Jesper
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    User Participation In Public e-service Development: Guidelines for including external users2014Doctoral thesis, comprehensive summary (Other academic)
  • 17.
    Holm, Magnus
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Adaptive Decision Support for Shop-floor Operators using Function Blocks2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    In manual and semi-automation production systems, flexibility and adaptability are affected by the shop-floor operators’ skills, abilities and knowledge. Such dependencies highlight the vital importance of developing and utilising the knowledge, achievements and abilities of the operators working with production on the shop-floor. Teamwork, including both novice and highly experienced shop-floor operators, in a production environment with a high level of automation, is essential already today and is predicted to increase, when the complexity and demands of future production systems intensify. This trend is confirmed in both the research literature and by specialists within industry.

    The key to future competitiveness and effectiveness of the manufacturing industry is the shop-floor operators who handle the production systems. In addition, the future information intensive working environment, with its increasing complexity and less time available for decision-making, demands adaptive decision support and adaptive control systems that facilitate collaborative work on the shop-floor. It is therefore important to emphasise how decisions are supported in the time-limited working environment of the shop-floor, because this has a large impact on production output and quality and is vital to the success of the company. Consequently, this dissertation presents a framework for an adaptive decision support system that concentrates on shop-floor operators, in order to enhance their development and future contribution to leading edge production systems.

    The overall aim of the research presented is to define a framework for an Adaptive Decision Support System, to address the scope and demands of the future shop-floor, as indicated in the research literature, and confirm its relevance, as well as further elaborate it on the basis of interviews with production managers and HR specialists

    The research presented uses the design science research process. In parallel, decision support systems and the industrial shop-floor have been studied in the research literature and the current state of industrial practice has been assessed. These areas together form the basis for the research on adaptive decision support for shop-floor operators. A framework enabling adaptive decision support and adaptive system control, based on event-driven function block technology and Augmented Reality technology, is formulated.

    The gap of research on decision support for shop-floor operators, indicated in the research literature is addressed by the research preformed.  Adaptive and dynamic decision support and system control able to process vast amounts of information in real time demonstrates utility for shop-floor operators. The research presenting the Adaptive Decision Support System has demonstrated its utility for shop-floor systems and production operatives in two extensive studies using demonstrators based on real-life production environments.

    A methodology, the ‘User group’, has been formulated for research collaboration and bi-directional knowledge transfer between academia and the industrial partners. It provides tools that enable cooperation between the experienced research partner and the novices, despite their different levels of engagement in the same project, without dividing them into separate groups. The ‘user group’ case study presented describes how both the inexperienced and the research mature companies gain new knowledge and engage in ongoing research. By doing so, the industrial project partners have extensively supported the research presented and will subsequently be the expected beneficiaries.

  • 18.
    Kaidalova, Julia
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre. Jönköping University, JTH.
    Integration of Product-IT into Enterprise Architecture: a metod for participatory Business and IT Alignment2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Enterprise Architecture (EA) is a practice for planning, representation and design of IT components and resources (Enterprise-IT) in an organization. In the context of digital transformation (DT), companies are exposed to various sorts of opportu-nities, both technological and business. Huge potential for value generation lies in Product-IT – built-in software and digital services enhancing the products, which is currently considered separately from Enterprise-IT. Integrated consideration of Product-IT and Enterprise-IT is hindered by various challenging factors, such as the mismatch between agile and traditional modes of IT development and mainte-nance, disjointed technology platforms and overall lack of methodological support to address Product-IT in a coherent way. This thesis proposes a method for Prod-uct-IT inclusive EA, which aims to support DT. The proposed method is the central artifact of the applied design science research, which was grounded and evaluated both theoretically and empirically (through literature reviews, an industrial case study and interviews). The proposed method has several parts: key concepts for product-IT inclusive EA modeling, expanding the traditional set of EA concepts; a set of focal areas to facilitate integrated modeling and analysis of Product-IT and Enterprise-IT; and a set of recommendations for participatory modeling of the pro-posed focal areas by relevant stakeholders.

  • 19.
    Kaidalova, Julia
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre. Jönköping University, School of Engineering.
    Towards a definition of the role of enterprise modeling in the context of business and IT alignment2015Licentiate thesis, monograph (Other academic)
    Abstract [en]

    In order to solve a problem of Business and IT Alignment (BITA) it is important to consider various dimensions of it: strategic, structural, social and cultural. In the context of dealing with BITA, Enterprise Modeling (EM) is an acknowledged and widely used practice. On one hand, EM facilitates the creation of integrated models that capture and represent different focal areas of an enterprise, there-fore it allowing to obtain a multidimensional view on an enterprise and to inte-grate these multiple dimensions into a coherent structure. These capabilities make EM a powerful tool for dealing with the strategic and structural dimen-sions of BITA. On the other hand, solving a BITA problem requires dealing with the numerous points of view of the stakeholders and creating a shared under-standing between them, which refers to the social and cultural dimensions of BITA. In this regard EM is also able to provide support to the development of an understanding about the current multidimensional praxis and future vision and strategies. Thus, EM has a high potential for dealing with the strategic, structur-al, social and cultural dimensions of BITA. This licentiate thesis investigates the applicability of EM in the light of BITA and proposes a framework that allocates intentions of EM application within the frame of the Strategic Alignment Model. The framework positions EM conceptually in the context of BITA and identifies a number of EM challenges and recommendations to suggest how EM can be used to facilitate BITA.

  • 20.
    Karlsson, Ingemar
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    An interactive decision support system using simulation-based optimization and knowledge extraction2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The use of simulation to improve existing manufacturing systems is not new, but simulation can also be used increase the understanding of production systems that have not yet been built. The power of simulation models can be further enhanced by using simulation-based optimization, in which an optimization algorithm tries to find optimal solutions, given certain objectives. However, extracting knowledge from the data resulting from simulation experiments and simulation-based optimization is a complex task. Therefore, tools are needed to assist users in this task. These tools can be visual, like diagrams, or can be generated by data mining. The process of running a study using simulation-based optimization to extract knowledge is a manual task that can in part be automated using existing tools, but to the author’s knowledge there is no software that implements the complete process. This work aims to develop a novel decision support system to support the generic decision process when using simulation and simulation-based optimization. The first step in setting up such a system is to understand how industry currently uses simulation and simulation-based optimization in manufacturing operations. Thus a questionnaire was distributed to manufacturing companies and organizations. The results showed that these techniques are being used, but that companies want more help with the analysis of the results as well as an automated guide in the decision process. This work proposes a system that supports a generic decision process by providing a tool with which a user can define a workflow in their organization, using simulation-based optimization as one component. The decision support system then provides tools for extracting knowledge in the form of diagrams and performs data mining for automated analysis. Data mining is part of the workflow as a tool for extracting knowledge after an optimization, as well as a tool for guiding optimization to suit the users’ preferences. The decision support system also provides for visualization of simulation models and optimization results using augmented reality. A head-mounted display helps users to see the results and model behaviors in 3D. This technology also makes it possible for users to collaborate, both in the same location and remotely. These visual and automatic analysis tools are shown to be effective in several application studies of real-world production scenarios in which data mining has been used to extract important knowledge that would be hard to obtain manually. Together with the automated workflow and efficient visualization of simulation and optimization results in augmented reality, the decision support system is believed to be an effective tool for extracting knowledge for general production systems design and analysis.

  • 21.
    Kashfi, S. Ruhollah
    University of Skövde, School of Engineering Science.
    Towards Evaluation of the Adaptive-Epsilon-R-NSGA-II algorithm (AE-R-NSGA-II) on industrial optimization problems2015Independent thesis Advanced level (degree of Master (One Year)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    Simulation-based optimization methodologies are widely applied in real world optimization problems. In developing these methodologies, beside simulation models, algorithms play a critical role. One example is an evolutionary multi objective optimization algorithm known as Reference point-based Non-dominated Sorting Genetic Algorithm-II (R-NSGA-II), which has shown to have some promising results in this regard. Its successor, R-NSGA-II-adaptive diversity control (hereafter Adaptive Epsilon-R-NSGA-II (AE-R-NSGA-II) algorithm) is one of the latest proposed extensions of the R-NSGA-II algorithm and in the early stages of its development. So far, little research exists on its applicability and usefulness, especially in real world optimization problems. This thesis evaluates behavior and performance of AE-R-NSGA-II, and to the best of our knowledge is one of its kind. To this aim, we have investigated the algorithm in two experiments, using two benchmark functions, 10 performance measures, and a behavioral characteristics analysis method.

    The experiments are designed to (i) assess behavior and performance of AE-R-NSGA-II, (ii) and facilitate efficient use of the algorithm in real world optimization problems. This is achieved through the algorithm parameter configuration (parametric study) according to the problem characteristics. The behavior and performance of the algorithm in terms of diversity of the solutions obtained, and their convergence to the optimal Pareto front is studied in the first experiment through manipulating a parameter of the algorithm referred to as Adaptive epsilon coefficient value (C), and in the second experiment through manipulating the Reference point (R) according to the distance between the reference point and the global Pareto front. Therefore, as one contribution of this study two new diversity performance measures (called Modified spread, and Population diversity), and the behavioral characteristics analysis method called R-NSGA-II adaptive epsilon value have been introduced and applied. They can be modified and applied for the evaluation of any reference point based algorithm such as the AE-R-NSGA-II. Additionally, this project contributed to improving the Benchmark software, for instance by identifying new features that can facilitate future research in this area.

    Some of the findings of the study are as follows: (i) systematic changes of C and R parameters influence the diversity and convergence of the obtained solutions (to the optimal Pareto front and to the reference point), (ii) there is a tradeoff between the diversity and convergence speed, according to the systematic changes in the settings, (iii) the proposed diversity measures and the method are applicable and useful in combination with other performance measures. Moreover, we realized that because of the unexpected abnormal behaviors of the algorithm, in some cases the results are conflicting, therefore, impossible to interpret. This shows that still further research is required to verify the applicability and usefulness of AE-R-NSGA-II in practice. The knowledge gained in this study helps improving the algorithm.

  • 22.
    Kolbeinsson, Ari
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Managing Interruptions in Manufacturing: Towards a Theoretical Framework for Interruptions in Manufacturing Assembly2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The effect of interruptions from ICT systems on assembly workers in manufacturing is examined in this thesis, as is how the risks of errors, increases in assembly time, increased cognitive load and resultant stress can be mitigated, as well as ensuring that important new information is acted upon. To these ends, a literature study was conducted, followed by two studies using an experimental approach in an environment that simulated a manufacturing assembly situation, and used tasks designed to be representative of manufacturing assembly tasks. The results of the literature study and the two studies are presented in four appended papers. The body of the thesis itself introduces similar material, and takes a step towards the creation of a theoretical framework that supports analysing the tasks and environments in question from a embodied and situated (DEEDS or 4E) viewpoint on cognition. This theoretical framework uses graphical representations similar to storyboards to support the analyst in maintaining an embodied and situated viewpoint during analyses of active tasks that require an examination of the interplay between brain, body, and environment. Supporting an embodied viewpoint during analysis has the purpose of facilitating the design of interruption coordination systems that take into account the embodied and situated nature of the tasks faced in manual tasks such as assembly in manufacturing.

  • 23.
    Kolbeinsson, Ari
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Situating interruptions in manufacturing assembly2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Interruptions have been studied extensively, with interruptions experiments where tasks performed on computers are interrupted by another task received on the same computer having receiving much of the focus. Additionally, many of the tasks used in existing research have been designed specifically to test the effect of interruptions on humans by making both the interrupting task and the task being interrupted quite difficult. The studies introduced here show that these commonly used tasks do not accurately represent some aspects of the manual tasks commonly performed by humans outside of laboratory experiments, with the experiments in this thesis focusing on manual tasks in assembly. A notable difference identified here is that interruptions in manual assembly tasks were seen to always contain a negotiation element, meaning that the person being interrupted could always modify to some extent when to respond to interruptions. Another central finding is that breakpoints for smart interruption systems need to be chosen using even more care than suggested by existing research because of an effect that can cause a notification to be completely missed when sent at a point that seemed opportune. This is due to apparent lulls in the activity containing preparation for the next action, or anticipation of action, using the Activity Theory (AT) terms used in the analysis of this effect. AT was identified as a useful tool for the analysis of manual assembly as it supports a hierarchical analysis of the activity and takes into account operator skill (task familiarity) in an easy to understand manner.AT was further used in an observational study where current approaches to interruption management were observed and explored. A surprising conclusion was that classical interruptions, as commonly defined, where one task is interrupted and another task must be completed before resuming the main (primary) task were exceedingly uncommon. This was found to be due to the high task familiarity (skill level) of the workers, the assembly activities being designed to minimise the risk of interruptions, and workers being trained to always finish the current operation before switching to another task. Workers did however engage in conversation and an interesting style of communication, dubbed ebb-and-flow style of negotiation, was identified. The differences between the results found in literature and the results of the studies were synthesised into a theoretical framework, or a collection of theories that work together to support the analysis of interruptions, and a visual support tool for the theoretical framework was created. This visual support tool, called an activity board both binds together the theories in a way that should make the theoretical framework easier to understand, and provides the beginnings of an analysis tool for interruption using the framework.

  • 24.
    Larsson, Carina
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Communicating performance measures: Supporting continuous improvement in manufacturing companies2017Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Manufacturing enterprises are a key driver of economic growth (Eurostat, 2016). Implementing continuous improvement (CI) is commonly used to increase competitiveness (Hyland et al., 2007), but despite the well-known theory of CI, many manufacturing companies fail in implementing it (Bhasin, 2012; Nordin et al., 2012; Tiwari et al., 2007).

    An identified critical success factor in CI implementation is the evaluation of performance, including the performance evaluation system itself, the linkage between targets at different company levels, and continual evaluation of performance (Bakås et al., 2011; Scherrer-Rathje et al., 2009; Ukko et al., 2009). Another critical success factor in CI implementation is the communication of performance measures (Bakås et al., 2011; Ukko et al., 2009).

    This research explores the communication of performance measures. The aim is to support CI by improving the communication of performance measures, and to this end, this thesis concentrates on identifying the main challenges in the communication of performance measures supporting CI. The research scope is manufacturing companies in general, and manufacturing SMEs in particular. The relevant literature concerning the communication of performance measures in manufacturing companies is identified and summarized. Also, current practice is explored, focusing on how performance measures are communicated in manufacturing companies, and whether and how the communication supports CI. This has been done to identify divergences between current practice and theory. Finally, theory and empirical findings are synthesized to identify some of the main challenges to be addressed in order to succeed in CI.

    The main task is to support CI efforts in manufacturing SMEs, eliminating the identified divergences in the communication of performance measures by adapting these measures to these manufacturing SMEs. These challenges can be summarized as follows: 

    - using both financial performance measures as well as objective and subjective, non-financial performance measures  - aligning performance measures with strategy and targets  - integrating all performance measure communication, as related to both daily performance and CI, in the same communication loop.  - forming two-way communication channels between managers and operators  - aligning oral and written communication channels  - exploring how information systems can facilitate the communication of performance measures  - using and optimizing the visual communication of performance measures

  • 25.
    Laxhammar, Rikard
    University of Skövde, School of Informatics.
    Conformal anomaly detection: Detecting abnormal trajectories in surveillance applications2014Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Human operators of modern surveillance systems are confronted with an increasing amount of trajectory data from moving objects, such as people, vehicles, vessels, and aircraft. A large majority of these trajectories reflect routine traffic and are uninteresting. Nevertheless, some objects are engaged in dangerous, illegal or otherwise interesting activities, which may manifest themselves as unusual and abnormal trajectories. These anomalous trajectories can be difficult to detect by human operators due to cognitive limitations.

    In this thesis, we study algorithms for the automated detection of anomalous trajectories in surveillance applications. The main results and contributions of the thesis are two-fold. Firstly, we propose and discuss a novel approach for anomaly detection, called conformal anomaly detection, which is based on conformal prediction (Vovk et al.). In particular, we propose two general algorithms for anomaly detection: the conformal anomaly detector (CAD) and the computationally more efficient inductive conformal anomaly detector (ICAD). A key property of conformal anomaly detection, in contrast to previous methods, is that it provides a well-founded approach for the tuning of the anomaly threshold that can be directly related to the expected or desired alarm rate. Secondly, we propose and analyse two parameter-light algorithms for unsupervised online learning and sequential detection of anomalous trajectories based on CAD and ICAD: the sequential Hausdorff nearest neighbours conformal anomaly detector (SHNN-CAD) and the sequential sub-trajectory local outlier inductive conformal anomaly detector (SSTLO-ICAD), which is more sensitive to local anomalous sub-trajectories.

    We implement the proposed algorithms and investigate their classification performance on a number of real and synthetic datasets from the video and maritime surveillance domains. The results show that SHNN-CAD achieves competitive classification performance with minimum parameter tuning on video trajectories. Moreover, we demonstrate that SSTLO-ICAD is able to accurately discriminate realistic anomalous vessel trajectories from normal background traffic.

  • 26.
    Linnéusson, Gary
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Towards strategic development of maintenance and its effects on production performance: A hybrid simulation-based optimization framework2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Managing maintenance in manufacturing within an economical short-termism framework and taking the consequential long-term cost effects into account is hard. The increasing complexity of managing maintenance and its impact on the business results calls for more advanced methods to support long-term development through effective activities in the production system environment. This problem-based design science research has evolved into the novel concept of a hybrid simulation-based optimization (SBO) framework which integrates multi-objective optimization (MOO) with system dynamics (SD) and discrete-event simulation (DES) respectively. The objective is to support managers in their decision-making on the strategic and operational levels for prioritizing activities to develop maintenance and production performance.

    To exemplify the hybrid SBO framework this research presents an SD model for the study of the dynamic behaviors of maintenance performance and costs, which aims to illuminate insights for the support of the long-term strategic development of maintenance practices. The model promotes a system view of maintenance costs that includes the dynamic consequential costs as the combined result of several interacting maintenance levels throughout the constituent feedback structures. These levels range from the applied combination of maintenance methodologies to the resulting proactiveness in production, such as the ratio between planned and unplanned downtime, in continuous change based on the rate of improvements arising from root-cause analyses of breakdowns. The model creation and validation process have been supported by two large maintenance organizations operating in the Swedish automotive industry. Experimental results show that intended changes can have both short-term and longterm consequences, and that the system may show both obvious and hidden dynamic behavioral effects.

    The application of MOO distinguishes this work from previous research efforts that have mixed SD and DES. It presents a unique methodology to support more quantitative and objective-driven decision making in maintenance management, in which the outcome of an SD+MOO strategy selection process forms the basis for performance improvements on the operations level. This is achieved by framing the potential gains in operations in the DES+MOO study, as a result of the applied strategy in the SD model. All in all, this hybrid SBO framework allows pinpointing maintenance activities based on the analysis of the feedback behavior that generates less reactive load on the maintenance organization.

  • 27.
    Nourizadeh, Alireza
    University of Skövde, School of Bioscience. No.
    APC, BRAF and KRAS mutations, and MLH1, MGMT and CDKN2A expression analysis in Nepalese colorectal cancer patients.: -2017Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Colorectal cancer (CRC) is a common malignancy which develops due to old age and lifestyle factors, low percent of patients afflicted by a genetic disorders. Half of all colorectal cancer patients are diagnosed after metastasis. The high rate of the late detection, emphasizes on the requirement of convenient and inexpensive diagnostic methods for comprehensive screening programs. The aim of this study was to discover proto-oncogenes mutation and assessment of tumor suppressor genes expression. Formalin fixed paraffin embedded (FFPE) histologically verified colorectal cancer samples were used. APC, KRAS and BRAF mutations were investigated using polymerase chain reaction (PCR) fragments and direct sequencing. Gene expression assessment of MLH1, MGMT and CDKN2A were achieved via quantitative polymerase chain reaction (qPCR). In the present study we could detect a novel transversion heterozygous mutation in APC gene codon 1365 in three patients. BRAF codon 600 mutation were detected in one patient. KRAS codon 12 mutation was discovered in one sample and also a novel transition mutation in codon 15 was detected in 6 patients. In 80% of cases, MLH1 and MGMT expression were undetectable, in remaining 20%, MLH1 expression were reduced, but MGMT showed both reduced and increased expression compared to control. In 100% of patients CDKN2A expression was undetectable. The rate of mutations in predetermined hotspot codons and amount of uncommon mutations into APC, BRAF and KRAS in Nepalese patients indicates the requirement of further investigation in CRC patients from that part of the world. Also, the expression rate of MLH1, MGMT, CDKN2A and deficiency of an information source emphasizes the necessity of whole genome CRC expression profiling data to comparison and conclusion. 

  • 28.
    Ohlander, Ulrika
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre. Saab AB.
    Towards Enhanced Tactical Support Systems2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Fighter pilots operate high-performing powerful aircraft, equipped with complex sensor systems, in a dynamic and hostile environment. The pilots need to have control over their own aircraft as well as the developing situation surrounding them. Moreover, the fighter pilot rarely is on a mission by himself, but collaborates with teammates to achieve the goals jointly. This collaboration between fighter aircraft cannot take place without technology in the form of a tactical support system (TSS) that aids the pilots with information retrieval and decision-making. A TSS in a fighter aircraft fuses data from different sources and organizes the information in order to assist the pilot in building situation awareness and support in the decision-making during missions. The capabilities of the aircraft and its sensors, as well as the design of the TSS will directly affect how the pilots can perform the missions. The technology and the design at the same time enable and constrain the possible acting space, such that the tactics and plans for the missions will be a consequence of these factors. Hence, the design and development of such a complex system requires deep knowledge about the users and understanding of how they will operate the system. High usability is among the requirements for such a specialized and advanced system as the TSS, and in order to achieve this there is a need to understand the circumstances the system will be used in. Due to the complex nature of the military operations and the difficulties to access the domain for others than pilots, it is challenging for designers of the TSSs to obtain this needed knowledge. Therefore, this thesis aims at investigating the nature of the operations, as well as the practice of user participation in the domain, in order to increase the designers’ knowledge and give guidance to how users should participate in the development of the systems. 

    Several methods that aim to design efficient and usable systems are available. User-centered design is a holistic philosophy that prescribes that the interests and needs of the users should be in focus through the whole development process in order to achieve better systems. At the core of user-centered design is to increase the knowledge about the users and their needs. This thesis applies two perspectives, which both contributes to fulfill the goal of user-centered design of the TSSs by obtaining more knowledge about the users. The two perspectives are: a better understanding of how the users/pilots utilize the TSS to perform teamwork during missions, and an insight into how the users/pilots participate during the development process of the TSSs. 

    The teamwork perspective is motivated by the fact that fighter pilots perform a majority of their missions collaborating in teams. Their teamwork is depending on technology since the pilots are separated from each other in their fighter airplanes. Understanding this teamwork is hence a key to understanding the users in this domain. This thesis investigates the nature of teamwork between fighter pilots based on a theoretical teamwork model, the  “Big Five” of effective teamwork proposed by Salas, Sims, and Burke (2005). The “Big Five” model contains eight elements that Salas et al. identified as necessary for effective teamwork: adaptability, backup behavior, closed-loop communication, shared mental models, mutual performance monitoring, team orientation, mutual trust, and team leadership. The user-participation perspective is based on the notion that involving the users in different stages through the development process will benefit the results. However, user participation can take many different forms. The users can have different roles during the process, and the impact their opinions will have on the product can vary. This thesis investigates user participation and the roles the users, i.e. pilots, have in the development process of fighter aircraft of TSSs and cockpit interfaces. 

    These two perspectives are each assigned an aim in the investigation. For the first aim, Increase the knowledge about how fighter pilots collaborate in teams during missions with the current systems, ten fighter pilots were interviewed about their views on teamwork. The teamwork elements of the “Big Five” model are explored and described for the military fighter context. With this knowledge, a task performance cycle is proposed which shows were in the cycle of a mission each teamwork element is most important. Finally, a modified teamwork model adapted for mission performance for fighter pilots is suggested.

    For the second aim, Increase the knowledge about how pilots can and should participate in the design process of fighter aircraft interfaces, a study on how pilots participate in the design work of cockpit interfaces is conducted. The inquiry is based on a questionnaire, which was distributed to designers of fighter cockpit interfaces. The results indicate that the designers think the pilots have and should have many different roles in the design process. The designers wish to be able to observe pilots at work to a greater extent and to obtain more information and ideas from them. They also think that pilots should be more involved as examiners and testers. However, pilots should not be designers or decision-makers regarding design, according to the majority of respondents. 

    The presented contributions of the team-related research in this thesis are a deeper understanding and rich descriptions of how fighter pilots perform missions from a teamwork perspective. The teamwork elements are examined, and their relations and their importance during mission performance are described. For example, it was found that the abilities to monitor each other, to adapt, and to communicate were the most important factors for effective teamwork during a mission. For the investigation of how designers of pilot interfaces work with user representatives in the design process, the contribution is a description of the different roles the users can have during the development process in this domain. The results are primarily intended to inform designers of tactical support systems and cockpit interfaces. However, other domains where team members are distributed, and are highly dependent on technology for their teamwork, should benefit from the findings. 

  • 29.
    Pinto, Nuno Alexandre
    University of Skövde, School of Bioscience.
    Lucid Dreaming and Consciousness: A Theoretical Investigation2015Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
  • 30.
    Rexhepi, Hanife
    University of Skövde, School of Informatics.
    BRIDGING THE INFORMATION GAP: Supporting Evidence-Based Medicine and Shared Decision-Making through Information Systems2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Practicing evidence-based medicine (EBM) and shared decision-making (SDM)along the patient process is important in today's healthcare environment, as thesemodels of care offer a way to improve quality and safety of care, patient satisfaction,and reduce costs. EBM is the conscientious and judicious use of current best medicalevidence in conjunction with clinical expertise. It also includes taking into accountpatient values and preferences to guide decisions about the care of individual patients.SDM offers a process that guides how a healthcare professional (e.g., a physicianor a nurse) and a patient jointly can participate in a decision after incorporatingthe body of evidence (the options, benefits and harms) and considering the patient'svalues and preferences.

    The degree to which healthcare professionals can practice EBM and SDM is dependentupon the availability of information about the patient (e.g., medical diagnosis,therapies as well as laboratory and administrative information) and medical evidence(such as medical guidelines). Patient information is a prerequisite for making decisionsabout the care of individual patients and it is evidence-based medicalknowledge, clinical expertise as well as patient values and preferences that guidethese decisions. Moreover, for patients to be able to communicate values and preferencesas well as participate effectively in their own care, they need to have a basicunderstanding of their condition and treatment options, and the consequences ofeach. Hence, they need access to the same information streams—in "patientaccessible"form—as their physician(s) and care team throughout their journey (process)in healthcare. However, making the right decisions about the care of individualpatients at the right time and place is a challenge for healthcare professionals. Due tointeroperability issues, existing information systems do not support a seamless flowof patient information along the patient process. Healthcare professionals are thereforeunable to easily access up-to-date information about the patient at the right timeand place. The situation is complicated further by the fragmentation of medical evidencein different repositories and its presentation by diverse providers, each withunique ideas about how information should be organized and how search enginesshould function. Limited or no access to relevant patient information and the bestmedical evidence about the benefits and risks of treatment options can result inflawed decisions and, more seriously, the suffering of patients. The situation also affectsSDM. If patients are not informed about their health condition, treatment options,benefits and risks or not given high quality information, e.g., becausehealthcare professionals do not have access to the best evidence, patients will be unIIable to assess 'what it is important to them', or they will make inadequate decisionsabout key issues. Consequently, it is almost impossible to practice EBM and SDM ineveryday clinical care.

    For EBM and SDM to serve their purpose, healthcare professionals and patients needinformation systems that provide quick and trouble-free access to all-round information.They also need information systems that can influence the patient/physicianrelationship and facilitate their pursuance of shared goals in the healthcare process,taking into account both illness and personal experience. Hence, based on a qualitativeapproach, this thesis proposes recommendations regarding the redesign of futurehealthcare information systems in ways that will facilitate, rather than hinder,the access to relevant information. One important recommendation identified is thatfuture healthcare information systems must support the core characteristics of EBMand SDM, in an integrated manner, and using the one without the other is notenough. However, such support requires the adoption of a process view on informationsystem development based on the patient's process. A process-oriented approachwith supporting information systems is thus vital for the support of an evidence-based practice where the patient is an important and active collaborator.Moreover, the challenges identified with regard to information system support arenot exclusively technical. Organizational culture, and the attitudes of healthcare professionalsto patient involvement are some of the biggest challenges facing healthcareorganizations.

  • 31.
    Rexhepi, Hanife
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Improving healthcare information systems: A key to evidence based medicine2015Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Delivering good quality care is a complex endeavor that is highly dependent on patient information and medical knowledge. When decisions about the care of a patient are made, they must, as far as possible, be based on research-derived evidence rather than on clinical skills and experience alone. Evidence based medicine (EBM) is the conscientious and judicious use of current best evidence in conjunction with clinical expertise as well as patient values and preferences to guide healthcare decisions. Following the principles of EBM, healthcare practitioners are required to formulate questions based on patients’ current clinical status, medical history, values and preferences, search the literature for answers, evaluate the evidence for its validity and usefulness, and finally apply the information to the patient. Information systems play a crucial role in the practice of evidence based medicine, by allowing healthcare practitioners to access clinical evidence and information about the patients’ health as they formulate their patient-care strategies. However, current information systems solutions are far from this perspective for various reasons. One of these reasons is that existing information systems do not support a seamless flow of patient information along the patient process. Due to interoperability issues, healthcare practitioners cannot easily exchange patient information from one information system to another and from one healthcare practitioner to another. Consequently, vital information that is stored in separate information systems and which could present a clear and complete picture of the patient cannot be easily accessed. All too often, units have to operate without knowledge of the problems addressed by other healthcare practitioners from other units, the services provided, medications prescribed, or preferences expressed in those previous situations. The practice of EBM is further complicated by current information systems that do not support practitioners in their search and evaluation of current evidence in everyday clinical care.

    Based on a qualitative approach, this work aims to find solutions for how future healthcare information systems can support the practice of EBM. By combining existing research on process orientation, knowledge management and evidence based medicine with empirical data, a number of recommendations have been initiated. These recommendations aim to support healthcare managers, IT–managers and system developers in the development of future healthcare information systems, from a process-oriented and knowledge management perspective. By following these recommendations, it is possible to develop information systems that facilitate the practice of evidence based medicine, and improve patient engagement.

  • 32.
    Schmidt, Bernard
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Toward Predictive Maintenance in a Cloud Manufacturing Environment: A population-wide approach2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The research presented in this thesis is focused on improving industrial maintenance by using better decision support that is based on a wider range of input information. The core objective is to research how to integrate information from a population of similar monitored objects. The data to be aggregated comes from multiple disparate sources including double ball-bar circularity tests, the maintenance management system, and the machine tool’s controller. Various data processing and machine learning methods are applied and evaluated. Finally, an economic evaluation of the proposed approach is presented. The work performed is presented in five appended papers.

    Paper I presents an investigation of cloud-based predictive maintenance concepts and their potential benefits and challenges.

    Paper II presents the results of an investigation of available and potentially useful data from the perspective of predictive analytics with a focus on the linear axes of machine tools.

    Paper III proposes a semantic framework for predictive maintenance, and investigates means of acquiring relevant information from different sources (i.e., ontology-based data retrieval).

    Paper IV presents a method for data integration. The method is applied to data obtained from a real manufacturing setup. Simulation-based evaluation is used to compare results with a traditional time-based approach.

    Paper V presents the results from additional simulation-based experiments based on the method from Paper IV. The aim is to improve the method and provide additional information that can support maintenance decision-making (e.g., determining the optimal interval for inspections).

    The method developed in this thesis is applied to a population of linear axes from a set of similar multipurpose machine tools. The linear axes of machine tools are very important, as their performance directly affects machining quality. Measurements from circularity tests performed using a double ball-bar measuring device are combined with event and context information to build statistical failure and classification models. Based on those models, a decision-making process is proposed and evaluated. In the analysed case, the proposed approach leads to direct maintenance cost reduction of around 40 % compared to a time-based approach.

  • 33.
    Tavara, Shirin
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    High-Performance Computing For Support Vector Machines2018Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Machine learning algorithms are very successful in solving classification and regression problems, however the immense amount of data created by digitalization slows down the training and predicting processes, if solvable at all. High-Performance Computing(HPC) and particularly parallel computing are promising tools for improving the performance of machine learning algorithms in terms of time. Support Vector Machines(SVM) is one of the most popular supervised machine learning techniques that enjoy the advancement of HPC to overcome the problems regarding big data, however, efficient parallel implementations of SVM is a complex endeavour. While there are many parallel techniques to facilitate the performance of SVM, there is no clear roadmap for every application scenario. This thesis is based on a collection of publications. It addresses the problems regarding parallel implementations of SVM through four research questions, all of which are answered through three research articles. In the first research question, the thesis investigates important factors such as parallel algorithms, HPC tools, and heuristics on the efficiency of parallel SVM implementation. This leads to identifying the state of the art parallel implementations of SVMs, their pros and cons, and suggests possible avenues for future research. It is up to the user to create a balance between the computation time and the classification accuracy. In the second research question, the thesis explores the impact of changes in problem size, and the value of corresponding SVM parameters that lead to significant performance. This leads to addressing the impact of the problem size on the optimal choice of important parameters. Besides, the thesis shows the existence of a threshold between the number of cores and the training time. In the third research question, the thesis investigates the impact of the network topology on the performance of a network-based SVM. This leads to three key contributions. The first contribution is to show how much the expansion property of the network impact the convergence. The next is to show which network topology is preferable to efficiently use the computing powers. Third is to supply an implementation making the theoretical advances practically available. The results show that graphs with large spectral gaps and higher degrees exhibit accelerated convergence. In the last research question, the thesis combines all contributions in the articles and offers recommendations towards implementing an efficient framework for SVMs regarding large-scale problems.

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