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- Berg Marklund, Björn, 1988-
(author)
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Unpacking Digital Game-Based Learning : The complexities of developing and using educational games
- 2015
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Doctoral thesis (other academic/artistic)abstract
- 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.
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| 2. |
- Al-Gburi, Majid
(author)
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Restraint Effects in Early Age Concrete Structures
- 2015
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Doctoral thesis (other academic/artistic)abstract
- One of the widespread issues in concrete structures is cracks occurring at early age. Cracks that appear in the young concrete may cause early start of corrosion of rebars or early penetration of harmful liquids or gases into the concrete body. These situations could result in reduced service life and in significantly increased maintenance cost of structures. Therefore it is important for construction companies to avoid these cracks.Volumetric deformations in early age concrete are caused by changes in temperature and/or the moisture state. If such movements are restrained, stresses will occur. If the tensile stresses are high enough, there will be a damage failure in tension and visible cracks arise. These stresses are always resulting from a self-balancing of forces, either within the young concrete bodyalone, i.e. without structural joints to other structures, or from the young concrete in combination with adjacent structures through structural joints.The decisive situation within a young concrete body alone is typically high stresses at the surface when the temperature is near the peak temperature within the body. This situation occur rather early for ordinary structures, say within a few days after casting for structures up to about some meters thickness, but for very massive structures like large concrete dams, it might take months and even years to reach the maximum tensile stresses at the surface. Usually this type of cracks is denoted "surface cracks", and in some cases only a temperature calculation may give a good perception to make decisions of the risk of surface cracking.On the other hand, the decisive situation within a young concrete body connected to adjacent structures, might include both risk of surface cracking at some distance away from the structural joint and risk of through cracking starting in the neighborhood of the structural joint. If the young concrete body is small in accordance to the adjacent structure, or, in other words, if thereis an overall high restraint situation in the young concrete, the risk of early surface cracking might be out of question. So, restraint from adjacent structures represents one of the main sources of thermal and shrinkage stresses in a young concrete body.This study is mainly concentrated on establishing the restraint inside the young concrete body counteracted by adjacent structures, and how to estimate the risk of through cracking based on such restraint distributions. The restraint values in the young concrete are calculated with use of the finite element method, FEM. Any spatial structure may be analyzed with respect to the level of restraint. Calculations of risk of cracking are demonstrated with use of existing compensation plane methods, and a novel method denoted equivalent restraint method, ERM, is developed for the use of restraint curves. ERM enables the use of both heating ofthe adjacent structure and/or cooling of the young concrete, which are the most common measures used on site to reduce the risk of early cracking.In a design situation many parameters are to be considered, like type of cement, different concrete mixes, temperature in the fresh concrete, surrounding temperatures, temperature in the adjacent structure, measures on site (heating/cooling/insulation), sequence order of casting.Therefore, in general a lot of estimations concerning risks of cracking are to be performed. The main objective with the present study is to develop methods speeding up and shorten the design process.Furthermore, established restraint curves have been applied to the method of artificial neural networks (ANN) to model restraint in the slab, wall, and roof for the typical structure Tunnel. It has been shown that ANN is capable of modeling the restraint with good accuracy. The usage of the neural network has been demonstrated to give a clear picture of the relative importance of the input parameters. Further, results from the neural network can be represented by a series of basic weight and response functions, which enables that the restraint curves easily can be made available to any engineer without use of complicated software.A new casting technique is proposed to reduce restraint in the newly cast concrete with a new arrangement of the structural joint to the existing old concrete. The proposed technique is valid for the typical structure wall-on-slab using one structural joint. This casting method means that the lower part of the wall is cast together with the slab, and that part is called a kicker. It hasbeen proven by the beam theory and demonstrated by numerical calculations that there is a clear reduction in the restraint from the slab to the wall using kickers.Restraint is affected by casting sequence as well as boundary conditions and joint position between old and new concrete elements. This study discusses the influence of different possible casting sequences for the typical structure wall-on-slab and slab-on-ground. The aim is to identify the sequence with the lowest restraint to reduce the risk of cracking.
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| 3. |
- Blissing, Björn
(author)
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Driving in Virtual Reality : Investigations in Effects of Latency and Level of Virtuality
- 2016
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Licentiate thesis (other academic/artistic)abstract
- When developing new active safety systems or improving existing systems, conducting performance evaluations is necessary. By performing these evaluations during early development stages, potential problems can be identified and mitigated before the system moves into the production phase.Testing active safety systems can be difficult since the characteristic scenarios may have complex interactions. Using real vehicles for performing these types of scenarios is difficult, expensive, and potentially dangerous. Alternative methods, such as using inflatable targets, scale models, computer simulations or driving simulators, also suffer from drawbacks. Consequently, using virtual reality as an alternative to the traditional methods has been proposed. In this case, a real vehicle is driven while wearing a head-mounted display that presents the scenario to the driver.This research aims to investigate the potential of such technology. Specifically, this work investigates how the chosen technology affects the driver. This investigation has been conducted through a literature review. A test platform was constructed, and two user studies using normal drivers were performed. The first study focused on the effects of visual time delays on driver behavior. This study revealed that lateral behavior changes with added time delays, whereas longitudinal behavior appears unaffected. The second study investigated how driver behavior is affected by different modes of virtuality. This study demonstrated that drivers perceived mixed reality as more difficult than virtual reality.The main contribution of this work is the detailed understanding of how time delays and different modes of virtuality affect drivers. This is important knowledge for selecting which scenarios are suitable for evaluation using virtual reality.
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| 4. |
- Stamm, Arne, et al.
(author)
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Chemo- enzymatic pathways toward pinene- based renewable materials
- 2019
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In: Green Chemistry. - : Royal Society of Chemistry (RSC). - 1463-9262 .- 1463-9270. ; 21:10, s. 2720-2731
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Journal article (peer-reviewed)abstract
- Sobrerol methacrylate (SobMA) was synthesized and subsequently polymerized using different chemical and enzymatic routes. Sobrerol was enzymatically converted from -pinene in a small model scale by a Cytochrome P450 mutant from Bacillus megaterium. Conversion of sobrerol into SobMA was performed using both classical ester synthesis, i.e., acid chloride-reactions in organic solvents, and a more green approach, the benign lipase catalysis. Sobrerol was successfully esterified, leaving the tertiary alcohol and ene to be used for further chemistry. SobMA was polymerized into PSobMA using different radical polymerization techniques, including free radical (FR), controlled procedures (Reversible Addition Fragmentation chain-Transfer polymerization, (RAFT) and Atom Transfer Radical Polymerization (ATRP)) as well as by enzyme catalysis (horseradish peroxidase-mediated free radical polymerization). The resulting polymers showed high glass-transition temperatures (T-g) around 150 degrees C, and a thermal degradation onset above 200 degrees C. It was demonstrated that the T-g could be tailored by copolymerizing SobMa with appropriate methacrylate monomers and that the Flory-Fox equation could be used to predict the T-g. The versatility of PSobMA was further demonstrated by forming crosslinked thin films, either using the ene'-functionality for photochemically initiated thiol-ene'-chemistry, or reacting the tertiary hydroxyl-group with hexamethoxymethylmelamine, as readily used for thermally curing coatings systems.
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