Change search
Refine search result
123 1 - 50 of 133
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Oldest first
  • Newest first
Select all
  • 1.
    Ahlström, Eric
    et al.
    Blekinge Institute of Technology.
    Holmqvist, Lucas
    Blekinge Institute of Technology.
    Goswami, Prashant
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Comparing Traditional Key Frame and Hybrid Animation2017Conference paper (Refereed)
    Abstract [en]

    In this research the authors explore a hybrid approach which usesthe basic concept of key frame animation together with proceduralanimation to reduce the number of key frames needed for an animationclip. The two approaches are compared by conducting anexperiment where the participating subjects were asked to ratethem based on their visual appeal.

  • 2.
    Anderdahl, Johan
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Darner, Alice
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Particle Systems Using 3D Vector Fields with OpenGL Compute Shaders2014Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [en]

    Context. Particle systems and particle effects are used to simulate a realistic and appealing atmosphere in many virtual environments. However, they do occupy a significant amount of computational resources. The demand for more advanced graphics increases by each generation, likewise does particle systems need to become increasingly more detailed. Objectives. This thesis proposes a texture-based 3D vector field particle system, computed on the Graphics Processing Unit, and compares it to an equation-based particle system. Methods. Several tests were conducted comparing different situations and parameters for the methods. All of the tests measured the computational time needed to execute the different methods. Results. We show that the texture-based method was effective in very specific situations where it was expected to outperform the equation-based. Otherwise, the equation-based particle system is still the most efficient. Conclusions. Generally the equation-based method is preferred, except for in very specific cases. The texture-based is most efficient to use for static particle systems and when a huge number of forces is applied to a particle system. Texture-based vector fields is hardly useful otherwise.

  • 3.
    Andersen, Dennis
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Screen-Space Subsurface Scattering, A Real-time Implementation Using Direct3D 11.1 Rendering API2015Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    Context Subsurface scattering - the effect of light scattering within a material. Lots of materials on earth possess translucent properties. It is therefore an important factor to consider when trying to render realistic images. Historically the effect has been used for offline rendering with ray tracers, but is now considered a real-time rendering technique and is done based on approximations off previous models. Early real-time methods approximates the effect in object texture space which does not scale well with real-time applications such as games. A relatively new approach makes it possible to apply the effect as a post processing effect using GPGPU capabilities, making this approach compatible with most modern rendering pipelines.

    Objectives The aim of this thesis is to explore the possibilities of a dynamic real-time solution to subsurface scattering with a modern rendering API to utilize GPGPU programming and modern data management, combined with previous techniques

    Methods The proposed subsurface scattering technique is implemented in a delimited real-time graphics engine using a modern rendering API to evaluate the impact on performance by conducting several experiments with specific properties.

    Results The result obtained hints that by using a flexible solution to represent materials, execution time lands at an acceptable rate and could be used in real-time. These results shows that the execution time grows nearly linearly with consideration to the number of layers and the strength of the effect. Because the technique is performed in screen space, the performance scales with subsurface scattering screen coverage and screen resolution.

    Conclusions The technique could be used in real-time and could trivially be integrated to most existing rendering pipelines. Further research and testing should be done in order to determine how the effect scales in a complex 3D-game environment.

  • 4.
    Andersson, Anders Tobias
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Facial Feature Tracking and Head Pose Tracking as Input for Platform Games2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Modern facial feature tracking techniques can automatically extract and accurately track multiple facial landmark points from faces in video streams in real time. Facial landmark points are defined as points distributed on a face in regards to certain facial features, such as eye corners and face contour. This opens up for using facial feature movements as a handsfree human-computer interaction technique. These alternatives to traditional input devices can give a more interesting gaming experience. They also open up for more intuitive controls and can possibly give greater access to computers and video game consoles for certain disabled users with difficulties using their arms and/or fingers.

    This research explores using facial feature tracking to control a character's movements in a platform game. The aim is to interpret facial feature tracker data and convert facial feature movements to game input controls. The facial feature input is compared with other handsfree inputmethods, as well as traditional keyboard input. The other handsfree input methods that are explored are head pose estimation and a hybrid between the facial feature and head pose estimation input. Head pose estimation is a method where the application is extracting the angles in which the user's head is tilted. The hybrid input method utilises both head pose estimation and facial feature tracking.

    The input methods are evaluated by user performance and subjective ratings from voluntary participants playing a platform game using the input methods. Performance is measured by the time, the amount of jumps and the amount of turns it takes for a user to complete a platform level. Jumping is an essential part of platform games. To reach the goal, the player has to jump between platforms. An inefficient input method might make this a difficult task. Turning is the action of changing the direction of the player character from facing left to facing right or vice versa. This measurement is intended to pick up difficulties in controling the character's movements. If the player makes many turns, it is an indication that it is difficult to use the input method to control the character movements efficiently.

    The results suggest that keyboard input is the most effective input method, while it is also the least entertaining of the input methods. There is no significant difference in performance between facial feature input and head pose input. The hybrid input version has the best results overall of the alternative input methods. The hybrid input method got significantly better performance results than the head pose input and facial feature input methods, while it got results that were of no statistically significant difference from the keyboard input method.

    Keywords: Computer Vision, Facial Feature Tracking, Head Pose Tracking, Game Control

  • 5. Astor, Philipp
    et al.
    Adam, Marc
    Jerčić, Petar
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Schaaff, Kristina
    Weinhardt, Christof
    Integrating biosignals into information systems: A NeuroIS tool for improving emotion regulation2013In: Journal of Management Information Systems, ISSN 0742-1222, E-ISSN 1557-928X, Vol. 30, no 3, 247-277 p.Article in journal (Refereed)
    Abstract [en]

    Traders and investors are aware that emotional processes can have material consequences on their financial decision performance. However, typical learning approaches for debiasing fail to overcome emotionally driven financial dispositions, mostly because of subjects' limited capacity for self-monitoring. Our research aims at improving decision makers' performance by (1) boosting their awareness to their emotional state and (2) improving their skills for effective emotion regulation. To that end, we designed and implemented a serious game-based NeuroIS tool that continuously displays the player's individual emotional state, via biofeedback, and adapts the difficulty of the decision environment to this emotional state. The design artifact was then evaluated in two laboratory experiments. Taken together, our study demonstrates how information systems design science research can contribute to improving financial decision making by integrating physiological data into information technology artifacts. Moreover, we provide specific design guidelines for how biofeedback can be integrated into information systems

  • 6.
    Bai, Guohua
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    An Organic View of Prototyping in Information System Development2015In: 2014 IEEE 17th International Conference on Computational Science and Engineering (CSE) / [ed] Liu, X; ElBaz, D; Hsu, CH; Kang, K; Chen, W, ChengDu: IEEE, 2015, Vol. Article number 07023844, 1814-1818 p.Conference paper (Refereed)
    Abstract [en]

    This paper presents an organic view of prototyping for managing dynamic factors involved in evolutionary design of information systems (IS). Those dynamic factors can be caused by, for example, continuing suggestions from users, changes in the technologies, and users-designers learning related stepwise progresses. Expanding the evolutionary prototyping to ‘start small and grow’, the organic view of prototyping proposes two prerequisites to do so, namely 1) a sustainable and adaptive ‘embryo’ – an organic structure of the future system, and 2) an embedded learning and feedback management that the actors of the system (users, designers, decision makers, administrators) can communicate with each other. An example of eHealth system design demonstrates how the prerequisites can be implemented.

  • 7.
    Bengtsson, Daniel
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Melin, Johan
    Constrained procedural floor plan generation for game environments2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Background: Procedural content generation (PCG) has become an important subject as the demand for content in modern games has increased. Paradox Arctic is a game development studio that aims to be at the forefront of technological solutions and is therefore interested in furthering their knowledge in PCG. To this end, Paradox Arctic has expressed their interest in a collaborative effort to further explore the subject of procedural floor plan generation.

    Objective: The main goal of this work is to test whether a solution based on growth, subdivision or a combination thereof, can be used to procedurally generate believable and varied floor plans for game environments, while also conforming to predefined constraints.

    Method: A solution capable of generating floor plans with the use of growth, subdivision and a combination of both has been implemented and a survey testing the believability and variation of the generated layouts has been conducted.

    Results & Conclusions: While the results of the subdivision and combined solutions show that more work is necessary before the generated content can be considered believable, the growth based solution presents promising results in terms of believability when generating smaller to medium sized layouts. This believability does however come at the cost of variation.

  • 8.
    Berg, Wilhelm
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Terränggenerering och dess påverkan på spelupplevelse2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Kontext. Inom speldesign är terräng ofta en viktig aspekt, särskilt i sammanhanget med spelare som ska aktivt interagera med terräng. Dess utformning och design kan både positivt och negativt påverka hur spelaren uppfattar spelet.

    Mål. I detta arbete beskrivs ett arbete i terränggenerering och om terräng kan påverka spelaren i ett interaktivt media för att få bättre förståelse inom ämnet. Har terrängen en påverkan på hur spelaren uppfattar situationer i spel samt deras sätt att spela? Kan den påverka om de uppfattar upplevelsen som negativ eller positiv? Vad är mest påverkande för en spelare och hur?

    Metoder. I arbetet kommer slutsatser och arbetssätt beskrivas tillsammans med data insamlad från ett praktiskt test. Designen för det spel som används för att testa kommer även att beskrivas. I arbetets testande låter vi deltagare spela ett spel som använder sig av en algoritm för att skapa terräng. Efter testet kommer spelare svara på frågor om testet.

    Resultat. Från testandet får vi in svar som används för att nå vissa slutsatser.

    Slutsatser. Från testets resultat kommer vi dra slutsatsen att terräng verkligen kan ha en påverkan på spelarupplevelsen och att terräng kan påverka när den har störst aktivt inverkan på hur spelaren interagerar med spelet.

  • 9.
    Bergsten, John
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Öhman, Konrad
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Player Analysis in Computer Games Using Artificial Neural Networks2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Star Vault AB is a video game development company that has developed the video game Mortal Online. The company has stated that they believe that players new to the game repeatedly find themselves being lost in the game. The objective of this study is to evaluate whether or not an Artificial Neural Network can be used to evaluate when a player is lost in the game Mortal Online. This is done using the free open source library Fast Artifical Neural Network Library. People are invited to a data collection event where they play a tweaked version of the game to facilitate data collection. Players specify whether they are lost or not and the data collected is flagged accordingly. The collected data is then prepared with different parameters to be used when training multiple Artificial Neural Networks. When creating an Artificial Neural Network there exists several parameters which have an impact on its performance. Performance is defined as the balance of high prediction accuracy against low false positive rate. These parameters vary depending on the purpose of the Artificial Neural Network. A quantitative approach is followed where these parameters are varied to investigate which values result in the Artificial Neural Network which best identifies when a player is lost. The parameters are grouped into stages where all combinations of parameter values within each stage are evaluated to reduce the amount of Artificial Neural Networks which have to be trained, with the best performing parameters of each stage being used in subsequent stages. The result is a set of values for the parameters that are considered as ideal as possible. These parameter values are then altered one at a time to verify that they are ideal. The results show that a set of parameters exist which can optimize the Artificial Neural Network model to identify when a player is lost, however not with the high performance that was hoped for. It is theorized that the ambiguity of the word "lost" and the complexity of the game are critical to the low performance.

  • 10.
    Blidkvist, Jesper
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Westgren, Joakim
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Re-texturing and compositing new material on pre-rendered media: Using DirectX and UV sampling2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Context: This thesis investigates a new method for re-texturing and com- positing new or additional material on specific pre-rendered images using various blend equations. This is done by sampling a number of render passes created alongside the original source material, most notably a UV pass for accurate texture positioning and different lighting passes to enhance the control over the final result. This will allow comparatively simple and cheap compositing without the overhead that other commercially available tools might add.

    Objectives: Render the necessary UV coordinates and lighting calculations from a 3D application to two separate textures.Sample said textures in DirectX and use the information to accurately light and position the additional dynamic material for blending with the pre-rendered media.

    Method: The thesis uses an implementation method in which quantita- tive data is gathered by comparing the resulting composited images using two common image comparison methods, the Structured Similarity Index (SSIM) and Peak Signal to Noise Ratio (PSNR), against a Gold Standard render.

    Results: The results of this implementation indicates that both the per- ceived and measured similarity is close enough to prove the validity of this method. Conclusions. This thesis shows the possibility and practical use of DirectX as tool capable of the most fundamental compositing operations. In its current state, the implementation is limited in terms of flexibility and func- tionality when compared to other proprietary compositing software packages and some visual artefacts and quality issues are present. There are however no indications that these issues could not be solved with additional work. 

  • 11.
    Boer, de, Wiebe Douwe
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Participatory Design Ideals2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Swedish academic discipline Informatics has roots in the Scandinavian design approach Participatory Design (PD). PD’s point of departure is to design ICT and the new environment it becomes part of together with the future users driven by the ideal to bring more democracy to the workplace. PD builds further on the Action Research and industrial democracy tradition already starting in the 1960s in Scandinavia, in which the powerful Scandinavian trade unions have a central role. The aim of the unions is to prepare the workers and have influence on the introduction of new technologies that (are expected to) change the work and work environment of the workers. In the 1970s, when more computers emerge in the work place, this leads to the development of PD. Important difference with AR is that the aim of PD is to actually design new ICT and the new environment it becomes part of.

    During the in PD literature much referred to project UTOPIA in the first half of the 1980s, led by project leader and PD pioneer Pelle Ehn, it is discovered that bringing the different expertise of designers/researchers and workers together in design-by-doing processes also result in more appropriate ICT.

     

    With ICT being ubiquitous nowadays, influencing most aspects of our lives, inside and outside the workplace, and another role of trade unions in (Scandinavian) society, a question is how PD should further develop. PD pioneer Morten Kyng (also a UTOPIA designer/researcher) proposes a framework for next PD practices in a discussion paper. The first element he mentions in the framework is ideals; The designer/researcher should as a first step consider what ideals to pursue as a person and for the project, and then to consider how to discuss the goals of the project partners, for which Kyng does no further suggestions how to approach this.

    This design and research thesis has as aim to design and propose some PD processes to come at the beginning of a PD/design project to shared ideals to pursue, based on a better understanding of the political and philosophical background of PD, including design as a discipline in its own right.

     

    For a better understanding of the political and philosophical roots of PD, and design as a discipline in its own right, Pelle Ehns’s early (PD research) work and (PD) influences and supporting theories are explored, next to Kyng’s discussion paper (framework) and reactions from his debate partners on this. Find out is that politics and what ideals to pursue in PD are sensitive and (still) important subjects in PD, and in a broader sense also for design in general one could argue. In relation to this also related disciplines like Computer Ethics, Value Sensitive Design, and more recent formulated ideals for PD and its relation to ethics are explored. As a result a proposal for a redesigned framework for next PD practices as a design artefact is designed, in which the element ideals is most elaborated.

    Before the understanding of design as a discipline in its own right is further explored by exploring a selection of different models and quotes from related (design) literature, on which is reflected also in relation to PD, and which are used as reminders in a design process to come to a proposal for a model that tries to reframe the relation between design, practice and research.

     

    Finally some methods, processes and techniques used in PD, design, AR and related literature that can contribute to design proposals for design processes that enable the design of ideals using a PD approach, are explored. These are used as reminders in design-by-doing processes, in which suggestions for techniques and processes to design ideals together with participants are tried out in real live situations, reflected on and iteratively further developed. Trying to avoid framing as much as possible, (semi-) anonymity and silence seem to be important ingredients in these processes to stimulate the generation of idea(l)s as much as possible free from bias and dominance patterns. An additional design artefact developed in this context is a template for an annotated portfolio used to describe and reflect on the different processes. 

  • 12.
    Brodén, Alexander
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Pihl Bohlin, Gustav
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Towards Real-Time NavMesh Generation Using GPU Accelerated Scene Voxelization2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Context. Producing NavMeshes for pathfinding in computer games is a time-consuming process. Recast and Detour is a pair of stateof-the-art libraries that allows automation of NavMesh generation. It builds on a technique called Scene Voxelization, where triangle geometry is converted to voxels in heightfields. The algorithm is expensive in terms of execution time. A fast voxelization algorithm could be useful in real-time applications where geometry is dynamic. In recent years, voxelization implementations on the GPU have been shown to outperform CPU implementations in certain configurations.

    Objectives. The objective of this thesis is to find a GPU-based alternative to Recast’s voxelization algorithm, and determine when the GPU-based solution is faster than the reference. Methods. This thesis proposes a GPU-based alternative to Recast’s voxelization algorithm, designed to be an interchangeable step in Recast’s pipeline, in a real-time application where geometry is dynamic. Experiments were conducted to show how accurately the algorithm generates heightfields, how fast the execution time is in certain con- figurations, and how the algorithm scales with different sets of input data.

    Results. The proposed algorithm, when run on an AMD Radeon RX 480 GPU, was shown to be both accurate and fast in certain configurations. At low voxelfield resolutions, it outperformed the reference algorithm on typical Recast reference models. The biggest performance gain was shown when the input contained large numbers of small triangles. The algorithm performs poorly when the input data has triangles that are big in relation to the size of the voxels, and an optional optimization was presented to address this issue. Another optimization was presented that further increases performance gain when many instances of the same mesh are voxelized.

    Conclusions. The objectives of the thesis were met. A fast, GPUbased algorithm for voxelization in Recast was presented, and conclusions about when it can outperform the reference algorithm were drawn. Possibilities for even greater performance gains were identified for future research.

  • 13. Bulling, Andreas
    et al.
    Dachselt, Raimund
    Duchowski, Andrew T.
    Jacob, Robert J.
    Stellmach, Sophie
    Sundstedt, Veronica
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Gaze Interaction in the Post-WIMP World2012Conference paper (Refereed)
    Abstract [en]

    With continuous progression away from desktop to post-WIMP applications, including multi-touch, gestural, or tangible interaction, there is high potential for eye gaze as a more natural human-computer interface in numerous contexts. Examples include attention-aware adaptations or the combination of gaze and hand gestures for interaction with distant displays. This SIG meeting provides a discussion venue for researchers and practitioners interested in gaze interaction in the post-WIMP era. We wish to draw attention to this emerging field and eventually formulate fundamental research questions. We will discuss the potential of gaze interaction for diverse application areas, interaction tasks, and multimodal user interface combinations. Our aims are to promote this research field, foster a larger research community, and establish the basis for a workshop at CHI 2013.

  • 14. Che, X.
    et al.
    Niu, Y.
    Shui, B.
    Fu, J.
    Fei, G.
    Goswami, Prashant
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Zhang, Y.
    A novel simulation framework based on information asymmetry to evaluate evacuation plan2015In: The Visual Computer, ISSN 0178-2789, E-ISSN 1432-2315, Vol. 31, no 6-8, 853-861 p.Article in journal (Refereed)
    Abstract [en]

    In this paper, we present a novel framework to simulate the crowd behavior under emergency situations in a confined space with multiple exits. In our work, we take the information asymmetry into consideration, which is used to model the different behaviors presented by pedestrians because of their different knowledge about the environment. We categorize the factors influencing the preferred velocity into two groups, the intrinsic and extrinsic factors, which are unified into a single space called influence space. At the same time, a finite state machine is employed to control the individual behavior. Different strategies are used to compute the preferred velocity in different states, so that our framework can produce the phenomena of decision change. Our experimental results prove that our framework can be employed to analyze the factors influencing the escape time, such as the number and location of exits, the density distribution of the crowd and so on. Thus it can be used to design and evaluate the evacuation plans. © 2015 Springer-Verlag Berlin Heidelberg

  • 15.
    Chu, Thi My Chin
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Zepernick, Hans-Jürgen
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    On Capacity of Full-Duplex Cognitive Cooperative Radio Networks with Optimal Power Allocation2017In: 2017 IEEE WIRELESS COMMUNICATIONS AND NETWORKING CONFERENCE (WCNC), IEEE , 2017Conference paper (Refereed)
    Abstract [en]

    In this paper, we examine a full-duplex transmission scheme for cognitive cooperative radio networks (CCRNs) to improve capacity. In this network, the secondary transmitter and secondary relay are allowed to utilize the licensed spectrum of the primary user by using underlay spectrum access. We assume that the CCRN is subject to the interference power constraint of the primary receiver and maximum transmit power limit of the secondary transmitter and secondary relay. Under these constraints, we propose an optimal power allocation policy for the secondary transmitter and the secondary relay based on average channel state information (CSI) to optimize capacity. Then, we derive an expression for the corresponding achievable capacity of the secondary network over Nakagami-m fading. Numerical results are provided for several scenarios to study the achievable capacity that can be offered by this full-duplex underlay CCRN using the proposed optimal power allocation scheme.

  • 16.
    Clementson, Martin
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Augustsson, John
    User Study of Quantized MIP Level Data In Normal Mapping Techniques2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

     The standard MIP mapping technique halves the resolution of textures for each level of the MIP chain. In this thesis the bits per pixel(bpp) is reduced as well. Normal maps are generally used with MIP maps, and todays industry standard for these are usually 24 bpp.The reduction is simulated as there is currently no support for the lower bpp in GPU hardware.

    Objectives: To render images of normal mapped objects with decreasing bpp for each level in a MIP chain and evaluate these against the standard MIP mapping technique using a subjective user study and an objective image comparison method.

    Methods: A custom software is implemented to render the images with quantized normal maps manually placed in a MIP chain. For the subjective experiment a 2AFC test is used, and the objective part consists of a PDIFF test for the images.

    Results: The results indicate that as the MIP level is increased and the bpp is lowered, users can increasingly see a difference.

    Conclusions: The results show that participants can see a difference as the bpp is reduced, which indicates normal mapping as not suitable for this method, however further study is required before this technique can be dismissed as an applicable method

  • 17.
    Danielsson, Max
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies. Blekinge Institute of Technology, Faculty of Computing, Department of Computer Science and Engineering.
    Sievert, Thomas
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies. Blekinge Institute of Technology, Faculty of Computing, Department of Computer Science and Engineering.
    Viability of Feature Detection on Sony Xperia Z3 using OpenCL2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Context. Embedded platforms GPUs are reaching a level of perfor-mance comparable to desktop hardware. Therefore it becomes inter-esting to apply Computer Vision techniques to modern smartphones.The platform holds different challenges, as energy use and heat gen-eration can be an issue depending on load distribution on the device.

    Objectives. We evaluate the viability of a feature detector and de-scriptor on the Xperia Z3. Specifically we evaluate the the pair basedon real-time execution, heat generation and performance.

    Methods. We implement the feature detection and feature descrip-tor pair Harris-Hessian/FREAK for GPU execution using OpenCL,focusing on embedded platforms. We then study the heat generationof the application, its execution time and compare our method to twoother methods, FAST/BRISK and ORB, to evaluate the vision per-formance.

    Results. Execution time data for the Xperia Z3 and desktop GeForceGTX660 is presented. Run time temperature values for a run ofnearly an hour are presented with correlating CPU and GPU ac-tivity. Images containing comparison data for BRISK, ORB andHarris-Hessian/FREAK is shown with performance data and discus-sion around notable aspects.

    Conclusion. Execution times on Xperia Z3 is deemed insufficientfor real-time applications while desktop execution shows that there isfuture potential. Heat generation is not a problem for the implemen-tation. Implementation improvements are discussed to great lengthfor future work. Performance comparisons of Harris-Hessian/FREAKsuggest that the solution is very vulnerable to rotation, but superiorin scale variant images. Generally appears suitable for near duplicatecomparisons, delivering much greater number of keypoints. Finally,insight to OpenCL application development on Android is given

  • 18. Dittrich, Yvonne
    et al.
    Eriksén, Sara
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Wessels, Bridgette
    Learning through Situated Innovation. Why the specific is crucial for Participatory Design Research2014In: Scandinavian Journal of Information Systems, ISSN 0905-0167 , Vol. 26, no 1Article in journal (Refereed)
    Abstract [en]

    Specific, situated Participatory Design (PD) practices have always been at the heart of Participatory Design research. The role of the very situat­edness and specificity of PD practice for theory-building within PD research is, however, seldom discussed explicitly. In this article, we explore why and in which ways the specificity and situatedness of PD practices are crucial for PD research. We do so by developing the notion of PD as situated innovation based on a pragmatic epistemology. PD research aims at devel­oping and continuously unfolding what PD can, might and should be. We show implica­tions of such a pragmatic epistemology of PD on understanding and arguing for PD research approaches. These concepts are illustrated referring to PD practices as experienced in PD research projects. Our epistemological argu­mentation supports the emphasis on ex­ploring new PD practices and learning and theorizing about PD from the spec­ificities, in line with recent debate contributions.

  • 19.
    Edänge, Simon
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    An Implementation and Performance Evaluation of a Peer-to-Peer Chat System2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Context: Chat applications have been around since the beginning of the modern internet. Today, there are many different chat systems with various communication solutions, but only a few utilize the fully decentralized Peer-to-Peer concept.

    Objectives: In this report, we want to investigate to see if a fully decentralized P2P concept is a suitable choice for chat applications. In order to investigate, a P2P architecture was selected and a simulation was implemented in Java. The simulation was used to make a performance evaluation in order see if the P2P concept could meet the requirements of a chat application, and to identify problems and difficulties.

    Methods: Two main methods were used in this thesis. First, a qualitative design method was used to identify and discuss different possibilities of designing a distributed chat application. Second, a performance evaluation was conducted to verify the selected and implemented mechanisms are able to obtain their general performance capabilities and to tune them towards anticipated performance.

    Results: The simulation proved that a decentralized P2P system can scale and find resources in a network quite efficiently without the need of any centralized service. It also proved to be simpler for the user to use the P2P concept, as no special configurations are needed. However, the selected protocol (Chord) had problems with high rates of churn, which could cause problems in big chat environments. The P2P concept was also shown to be highly complex to implement.

    Conclusion: P2P technology is a more complex technology, but it gives the host a lower cost in terms of hardware and maintenance. It also makes the system more robust and fault-tolerant. As we have seen in this report, P2P can scale and find other resources efficiently without the need of a centralized service. However, it will consume more power for each user, which makes mobile devices bad peers.

  • 20.
    Ejdemyr, Niclas
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Eye Tracking as an Additional Input Method in Video Games: Using Player Gaze to Improve Player Immersion and Performance2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Context. Gaze based interaction in video games is still a developing field, and is mostly used as an off-line evaluation tool or a replacement for traditional input methods. This thesis will look closer at the prospect of using eye tracking as an additional input to be used alongside the traditional methods of input to improve the immersion and performance of the player.

    Objectives. To implement a gaze based interaction method into arst person adventure in a way to improve player performance and immersion.

    Method. Using the Tobii REX eye tracker, 18 volunteers participated in an experiment. They played two versions of a game in an controlled environment. The versions had the same mechanics and game elements but only one of them had eye tracking implemented. After the experiment the participants answered nine questions about which prototype they preferred.

    Results. All participants' scores were in all cases but one, lower when using the eye tracking input method, compared to the traditional one.The time it took for the participants to complete the game was longer for everybody. 16 out of 18 players also felt more immersed in the game while using eye tracking compared to playing with the traditional input method.

    Conclusions. The results from the experiments provided evidence that the interaction method designed for this thesis did not improve player performance. The results also showed that the interaction method did improve immersion for most players.

  • 21. Ekelin, Annelie
    et al.
    Eriksén, Sara
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Citizen-Driven Design: Leveraging Participatory Design of E-Government 2.0 Through Local and Global Collaborations.2014In: Case Studies in e-Government 2.0. Changing Citizen Relationships. / [ed] Boughzala, Imed; Janssen, Marijn; Assar, Saïd, Springer , 2014Chapter in book (Refereed)
    Abstract [en]

    The goal of this paper is to present how citizen-driven design of e-government can be promoted through trans-local cooperation. Our case study consists of the Augment project, which focuses on the design of a mobile service for co-creation of local accessibility. Our approach is action research based in the Scandinavian tradition of Participatory design. Experiences from this project highlight issues concerning how to reconfigure the basis for design of public services. In order to cultivate spaces for citizen-driven design and local innovation, we made iterative use of global collaborations. In the initial phase, influences from R&D cooperation with India provided new spaces for participatory design practices. In the next phase, a proof-of-concept process allowed for broader local stake-holder involvement. In the third phase, the service concept was shared and expanded with partner regions in Europe through exchange of Best Practices. Currently, we are moving towards phase four, the commercialization process. Beyond the iterative design of the mobile service itself, and what trans-local collaboration contributed in this context, we also discuss reconceptualization of innovation as incremental change. We argue that transnational collaboration can be deliberately made use of for leveraging incremental change on a local level and strengthening regional innovation systems and practices.

  • 22.
    Eliasson, André
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Franzén, Pontus
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Accelerating IISPH: A Parallel GPGPU Solution Using CUDA2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Context. Simulating realistic fluid behavior in incompressible fluids for computer graphics has been pioneered with the implicit incompressible smoothed particle hydrodynamics (IISPH) solver. The algorithm converges faster than other incompressible SPH-solvers, but real-time performance (in the perspective of video games, 30 frames per second) is still an issue when the particle count increases.

    Objectives. This thesis aims at improving the performance of the IISPH-solver by proposing a parallel solution that runs on the GPU using CUDA. The solution should not compromise the physical accuracy of the original solution. Investigated aspects are execution time, memory usage and physical accuracy.

    Methods. The proposed implementation uses a fine-grained approach where each particle is calculated on a separate thread. It is compared to a sequential and a parallel OpenMP implementation running on the CPU.

    Results and Conclusions. It is shown that the parallel CUDA solution allow for real-time performance for approximately 19 times the amount of particles than that of the sequential implementation. For approximately 175 000 particles the simulation runs at the constraint of real-time performance, more particles are still considered interactive. The visual result of the proposed implementation deviated slightly from the ones on the CPU.

  • 23.
    Eliasson, Christopher
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Natural Language Generation for descriptive texts in interactive games2014Student thesis
    Abstract [en]

    Context. Game development is a costly process and with today's advanced hardware the customers are asking for more playable content, and at higher quality. For many years providing this content procedurally has been done for level creation, modeling, and animation. However, there are games that require content in other forms, such as executable quests that progress the game forward. Quests have been procedurally generated to some extent, but not in enough detail to be usable for game development without providing a handwritten description of the quest. Objectives. In this study we combine a procedural content generation structure for quests with a natural language generation approach to generate a descriptive summarized text for quests, and examine whether the resulting texts are viable as quest prototypes for use in game development. Methods. A number of articles on the area of natural language generation is used to determine an appropriate way of validating the generated texts produced in this study, which concludes that a user case study is appropriate to evaluate each text for a set of statements. Results. 30 texts were generated and evaluated from ten different quest structures, where the majority of the texts were found to be good enough to be used for game development purposes. Conclusions. We conclude that quests can be procedurally generated in more detail by incorporating natural language generation. However, the quest structure used for this study needs to expand into more detail at certain structure components in order to fully support an automated system in a flexible manner. Furthermore due to semantics and grammatics being key components in the flow and usability of a text, a more sophisticated system needs to be implemented using more advanced techniques of natural language generation.

  • 24.
    Engman, Robin
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    HPA* Used With a Triangulation-Based Graph2014Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [en]

    Context: Pathfinding is an important phase when it comes to AI. The AI needs to know how to get from one point to another when there are obstacles ahead. For that reason, different pathfinding algorithms have been created. Objective: In this paper a new pathfinding algorithm, THPA*, is described, and it will also be compared to the more common algorithms, A*, and HPA* which THPA* is based on. Methods: These algorithms are then tested on an extensive array of maps with different paths and the results consisting of the execution times will be compared against each other. Results: The result of those tests conclude that THPA* performs better in terms of execution time in the average case; however it does suffer from low quality paths. Conclusions: This paper concludes that THPA* is a promising algorithm albeit in need of more refinement to make up for the negative points.

  • 25.
    Eriksen, Sara
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Georgsson, Mattias
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Hofflander, Malin
    Blekinge Institute of Technology, Faculty of Health Sciences, Department of Health.
    Nilsson, Lina
    Blekinge Institute of Technology, Faculty of Health Sciences, Department of Health. Blekinge Inst Technol, Karlskrona, Sweden..
    Lundberg, Jenny
    Lund Univ, Dept Design Sci, Lund, Sweden..
    Health in Hand: Putting mHealth Design in Context2014In: 2014 IEEE 2ND INTERNATIONAL WORKSHOP ON USABILITY AND ACCESSIBILITY FOCUSED REQUIREMENTS ENGINEERING (USARE), 2014, 36-39 p.Conference paper (Refereed)
    Abstract [en]

    Wireless technologies, cloud computing and connectivity have enabled mobile services that extend the coverage of health services, resulting in a branch of eHealth now commonly referred to as mHealth. However, at least in Sweden, where the healthcare sector is heavily institutionalized and regulated, mHealth has so far mainly evolved in the form of applications for support of healthy life-style and self-management of chronic diseases, implemented outside of the firewalls of traditional healthcare delivery environments. In this paper we present an on-going Indo-Swedish research and development project in which we are putting mHealth design into context both from a patient's perspective and from the perspective of a healthcare team working within a professional healthcare organization. Our research approach is inspired by the Scandinavian tradition of Participatory Design of ICT and informed by studies of how to measure usability, user experience and impact of mHealth interventions. The involved research teams are multi-disciplinary, including researchers from engineering, computing and health sciences. The project includes, on the Swedish side, a partner from the public healthcare sector, three SME:s and an industrial partner who is currently providing Electronic Patient Record and other healthcare information system solutions and who is interested in developing mobile solutions for healthcare professionals. We are currently in the process of collaborative articulation and specification of problems, goals and requirements within the framework of the first Swedish case study of the project, focused on mobile support for patients with diabetes type 2 and their healthcare teams.

  • 26.
    Eriksén, Sara
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    The curse of the smart manager?: Digitalisation and the children of management science2016In: Scandinavian Journal of Information Systems, ISSN 0905-0167, Vol. 28, no 2, 76-77 p., 6Article in journal (Refereed)
    Abstract [en]

    In this commentary of Carsten Sørensen's keynote address and commentary, I argue that it may be the concept of the smart manager—so fundamental to management science—rather than the concept of the smart machine, which is still haunting IS research today. © Scandinavian Journal of Information Systems, 2016.

  • 27.
    Eriksén, Sara
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Lundberg, Jenny
    Blekinge Institute of Technology, Faculty of Engineering, Department of Applied Signal Processing.
    Georgsson, Mattias
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Nilsson, Lina
    Blekinge Institute of Technology, Faculty of Health Sciences, Department of Health.
    Hofflander, Malin
    Blekinge Institute of Technology, Faculty of Health Sciences, Department of Health.
    Borg, Christel
    Blekinge Institute of Technology, Faculty of Health Sciences, Department of Health.
    Transforming Healthcare Delivery: ICT Design for Self-Care of Type 2 Diabetes2014Conference paper (Refereed)
    Abstract [en]

    In this position paper we present an on-going case study where the aim is to design and implement mobile technologies for self-care for patients with type 2 diabetes. The main issue we are addressing in this paper is how to bridge clinical and non-clinical settings when designing self-care technologies. Usability, User Experience and Participatory Design are central aspects of our research approach. For designing with and for patients in home settings and everyday life situations, this approach has so far not been problematic. However, when it comes to designing with and for user groups located within a large healthcare organization, in a highly institutionalized clinical setting, the situation is different. We have recently introduced the Health Usability Maturity Model (UMM) to our project partners as a potential tool for bringing usability and participa-tory design issues to the fore as strategic assets for transforming healthcare delivery with ICT.

  • 28.
    Falkenby, Jesper Hansson
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Physically-based fluid-particle system using DirectCompute for use in real-time games2014Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [en]

    Context: Fluid-particle systems are seldom used in games, the apparent performance costs of simulating a fluid-particle system discourages the developer to implement a system of such. The processing power delivered by a modern GPU enables the developer to implement complex particle systems such as fluid-particle systems. Writing efficient fluid-particle systems is the key when striving for real-time fluid-particle simulations with good scalability. Objectives: This thesis ultimately tries to provide the reader with a well-performing and scalable fluid-particle system simulated in real-time using a great number of particles. The fluid-particle system implements two different fluid physics models for diversity and comparison purposes. The fluid-particle system will then be measured for each fluid physics model and provide results to educate the reader on how well the performance of a fluid-particle system might scale with the increase of active particles in the simulation. Finally, a performance comparison of the particle scalability is made by completely excluding the fluid physics calculations and simulate the particles using only gravity as an affecting force to be able to demonstrate how taxing the fluid physics calculations are on the GPU. Methods: The fluid-particle system has been run using different simulation scenarios, where each scenario is defined by the amount of particles being active and the dimensions of our fluid-particle simulation space. The performance results from each scenario has then been saved and put into a collection of results for a given simulation space. Results: The results presented demonstrate how well the fluid-particle system actually scales being run on a modern GPU. The system reached over a million particles while still running at an acceptable frame rate, for both of the fluid physics models. The results also shows that the performance is greatly reduced by simulating the particle system as a fluid-particle one, instead of only running it with gravity applied. Conclusions: With the results presented, we are able to conclude that fluid-particle systems scale well with the number of particles being active, while being run on a modern GPU. There are many optimizations to be done to be able to achieve a well-performing fluid-particle system, when developing fluid-particle system you should be wary of the many performance pitfalls that comes with it.

  • 29.
    Frank, Elias
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Olsson, Niclas
    Procedural city generation using Perlin noise2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Context. Procedural content generation is to algorithmically generate content. This has been used in games and is an important tool to create games with large amounts of content using fewer resources. This may allow small developers to create big worlds, which makes the investigation into this area interesting.

    Objectives. The Procedural generation of cities using Perlin noise is explored. The goal is to nd out if a procedurally generated city using Perlin noise is viable to use in games.

    Method. An implementation generating cities using Perlin noise has been created and a user study along with data collection tests the cities' viability in games.

    Result. The implementation succeeds with all the technical requirements such as performance and determinism. The user study shows that the cities created are perceived as viable in games.

    Conclusion. The cities generated with the implementation seems to be viable in games. The results show that the generated content are percieved as more viable than random generated cities. Furthermore the generation speed is fast enough to be used in an online setting.

  • 30.
    Frid Kastrati, Mattias
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Hybrid Ray-Traced Reflections in Real-Time: in OpenGL 4.32015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Context. Reaching photo realistic results when rendering 3D graphics in real-time is a hard computational task. Ray-tracing gives results close to this but is too expensive to be run at real-time frame rates. On the other hand rasterized methods such as deferred rendering are able to keep the tight time constraints with the support of modern hardware.

    Objectives. The basic objective is to merge deferred rendering and ray-tracing into one rasterized pipeline for dynamic scenes. In the thesis the proposed method is explained and compared to the methods it merges. Image quality, execution time and VRAM usage impact are investigated.

    Methods. The proposed method uses deferred rendering to render the result of the primary rays. Some pixels are marked, based on material properties for further rendering with ray-tracing. Only reflections are presented in the thesis but it has been proven that other global illumination effects can be implemented in the ray-tracing framework used.

    Results and Conclusions. The hybrid method is proved through experiments to be between 2.49 to 4.19 times faster than pure ray-tracing in the proposed pipeline. For smaller scenes it can be run at frame rates close to real-time, but, for larger scenes such as the Crytek Sponza scene the real-time feeling is lost. However, interactivity is never lost. It is also proved that a simple adjustment to the original framework can save almost 2/3 of the memory spent on A-buffers. Image comparisons prove that the technique can compete with offline ray tracers in terms of image quality.

  • 31.
    Frid Kastrati, Mattias
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Goswami, Prashant
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Selective rasterized ray-traced reflections on the GPU2016In: Eurographics Proceedings STAG 2016 / [ed] Andrea Giachetti and Silvia Biasotti and Marco Tarini, Eurographics - European Association for Computer Graphics, 2016Conference paper (Refereed)
    Abstract [en]

    Ray-tracing achieves impressive effects such as realistic reflections on complex surfaces but is also more computationally expensive than classic rasterization. Rasterized ray-tracing methods can accelerate ray-tracing by taking advantage of the massive parallelization available in the rasterization pipeline on the GPU. In this paper, we propose a selective rasterized raytracing method that optimizes the rasterized ray-tracing by selectively allocating computational resources to reflective regions in the image. Our experiments suggest that the method can speed-up the computation by up to 4 times and also reduce the memory footprint by almost 66% without affecting the image quality. We demonstrate the effectiveness of our method using complex scenes and animations.

  • 32.
    Georgsson, Mattias
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Weir, Charlene
    A Modified User-Oriented Heuristic Evaluation of a Mobile Health System for Diabetes Self-management Support2016In: Computers, Informatics, Nursing, ISSN 1538-2931, E-ISSN 1538-9774, Vol. 34, no 2, 77-84 p.Article in journal (Refereed)
    Abstract [en]

    Mobile health platforms offer significant opportunities for improving diabetic self-care, but only if adequate usability exists. Expert evaluations such as heuristic evaluation can provide distinct usability information about systems. The purpose of this study was to complete a usability evaluation of a mobile health system for diabetes patients using a modified heuristic evaluation technique of (1) dual-domain experts (healthcare professionals, usability experts), (2) validated scenarios and user tasks related to patients' self-care, and (3) in-depth severity factor ratings. Experts identified 129 usability problems with 274 heuristic violations for the system. The categories Consistency and Standards dominated at 24.1% (n = 66), followed by Match Between System and Real World at 22.3% (n = 61). Average severity ratings across system views were 2.8 (of 4), with 9.3% (n = 12) rated as catastrophic and 53.5% (n = 69) as major. The large volume of violations with severe ratings indicated clear priorities for redesign. The modified heuristic approach allowed evaluators to identify unique and important issues, including ones related to self-management and patient safety. This article provides a template for one type of expert evaluation adding to the informaticists' toolbox when needing to conduct a fast, resource-efficient and user-oriented heuristic evaluation. 

  • 33.
    Georgsson, Mattias
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Quantifying usability: an evaluation of a diabetes mHealth system on effectiveness, efficiency, and satisfaction metrics with associated user characteristics2016In: JAMIA Journal of the American Medical Informatics Association, ISSN 1067-5027, E-ISSN 1527-974X, Vol. 23, no 1, 5-11 p.Article in journal (Refereed)
    Abstract [en]

    Objective Mobile health (mHealth) systems are becoming more common for chronic disease management, but usability studies are still needed on patients' perspectives and mHealth interaction performance. This deficiency is addressed by our quantitative usability study of a mHealth diabetes system evaluating patients' task performance, satisfaction, and the relationship of these measures to user characteristics. Materials and Methods We used metrics in the International Organization for Standardization (ISO) 9241-11 standard. After standardized training, 10 patients performed representative tasks and were assessed on individual task success, errors, efficiency (time on task), satisfaction (System Usability Scale [SUS]) and user characteristics. Results Tasks of exporting and correcting values proved the most difficult, had the most errors, the lowest task success rates, and consumed the longest times on task. The average SUS satisfaction score was 80.5, indicating good but not excellent system usability. Data trends showed males were more successful in task completion, and younger participants had higher performance scores. Educational level did not influence performance, but a more recent diabetes diagnosis did. Patients with more experience in information technology (IT) also had higher performance rates. Discussion Difficult task performance indicated areas for redesign. Our methods can assist others in identifying areas in need of improvement. Data about user background and IT skills also showed how user characteristics influence performance and can provide future considerations for targeted mHealth designs. Conclusion Using the ISO 9241-11 usability standard, the SUS instrument for satisfaction and measuring user characteristics provided objective measures of patients' experienced usability. These could serve as an exemplar for standardized, quantitative methods for usability studies on mHealth systems.

  • 34.
    Georgsson, Mattias
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Kushniruk, A.
    School of Health Information Science, University of Victoria, VIC, Canada.
    Mediating the cognitive walkthrough with patient groups to achieve personalized health in chronic disease self-management system evaluation2016In: Studies in Health Technology and Informatics, IOS Press, 2016, Vol. 224, 146-151 p.Conference paper (Refereed)
    Abstract [en]

    The cognitive walkthrough (CW) is a task-based, expert inspection usability evaluation method involving benefits such as cost effectiveness and efficiency. A drawback of the method is that it doesn’t involve the user perspective from real users but instead is based on experts’ predictions about the usability of the system and how users interact. In this paper, we propose a way of involving the user in an expert evaluation method by modifying the CW with patient groups as mediators. This along with other modifications include a dual domain session facilitator, specific patient groups and three different phases: 1) a preparation phase where suitable tasks are developed by a panel of experts and patients, validated through the content validity index 2) a patient user evaluation phase including an individual and collaborative process part 3) an analysis and coding phase where all data is digitalized and synthesized making use of Qualitative Data Analysis Software (QDAS) to determine usability deficiencies. We predict that this way of evaluating will utilize the benefits of the expert methods, also providing a way of including the patient user of these self-management systems. Results from this prospective study should provide evidence of the usefulness of this method modification. © 2016 The authors and IOS Press. All rights reserved.

  • 35.
    Georgsson, Mattias
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Nancy, Staggers
    An evaluation of patients' experienced usability of a diabetes mHealth system using a multi-method approach2016In: Journal of Biomedical Informatics, ISSN 1532-0464, E-ISSN 1532-0480, Vol. 59, 115-129 p.Article in journal (Refereed)
  • 36.
    Georgsson, Mattias
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Staggers, N.
    Heuristic evaluation of a mhealth diabetes self-management system using disease specific patient profiles2016In: Studies in Health Technology and Informatics, IOS Press, 2016, Vol. 225, 530-534 p.Conference paper (Refereed)
    Abstract [en]

    Patient-centeredness is an important concept in diabetes treatment. We modified Nielsen’s expert heuristic evaluation method addressing common gaps: a patient perspective and variability in findings. Two expert, dual-domain evaluators referred to validated patient profiles (mild, moderate, severe diabetes) when conducting uniform evaluation processes on a diabetes mHealth system. Evaluators found 103 usability problems and 224 heuristic violations. For 69 % of the problems, the profiles had an effect on severity ratings. "Consistency and Standards" (n=57) and "Match between the System and Real World" (n=55) violations dominated at 50%. The overall system severity rating was major. Severity was highest for a severe diabetic profile due to likely visual issues (crowded elements), cognitive concerns (remembering many steps) and for insufficient medication information. Interrater reliability was respectable at Kappa =0.67. Our novel evaluation method represents one way of improving on a usability expert technique making it more patient-centered with less individual evaluator variability. © 2016 IMIA and IOS Press.

  • 37.
    Georgsson, Mattias
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Staggers, Nancy
    University of Utah, USA.
    Patients' Perceptions and Experiences of a mHealth Diabetes Self-management System2017In: Computers, Informatics, Nursing, ISSN 1538-2931, E-ISSN 1538-9774, Vol. 35, no 3, 122-130 p.Article in journal (Refereed)
    Abstract [en]

    Chronic diseases, including diabetes, constitute a substantial disease burden around the world. Mobile self-management systems now play a significant and increasingly important role in patients' disease management. Yet, patients' perceptions of these systems after longer-term use are largely unexplored. A random sample of 10 diabetes patients was assessed immediately after they exited a larger, 6-month randomized controlled trial on the use of a mHealth system called Care4Life. This descriptive, exploratory study assessed patients' perceptions and experiences of mHealth using a questionnaire and semistructured interview whose development was guided by the Technology Acceptance Model. Results indicated that patients saw clear benefits in using the technology and had favorable behavioral disease outcomes after using Care4Life. Suggestions for improving the system were highly individual despite the apparent homogeneity of the patient group. The study begins to fill the gap about the longer-term use of mHealth systems in chronic disease management and reflects the significance of individual needs for mHealth systems.

  • 38.
    Georgsson, Mattias
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Weir, Charlene
    Staggers, Nancy
    Revisiting Heuristic Evaluation Methods to Improve the Reliability of Findings2014Conference paper (Refereed)
    Abstract [en]

    The heuristic evaluation (HE) method is one of the most common in the suite of tools for usability evaluations because it is a fast, inexpensive and resource-efficient process in relation to the many usability issues it generates. The method emphasizes completely independent initial expert evaluations. Inter-rater reliability and agreement coefficients are not calculated. The variability across evaluators, even dual domain experts, can be significant as is seen in the case study here. The implications of this wide variability mean that results are unique to each HE, results are not readily reproducible and HE research on usability is not yet creating a uniform body of knowledge. We offer recommendations to improve the science by incorporating selected techniques from qualitative research: calculating inter-rater reliability and agreement scores, creating a codebook to define concepts/categories and offering crucial information about raters' backgrounds, agreement techniques and the evaluation setting.

  • 39.
    Gislén, Mikael
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Achieving Agile Quality: An Action Research Study2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 40.
    Goswami, Prashant
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies. BTH.
    Real-time landscape-size convective clouds simulation2015In: Proceedings of the 19th ACM Symposium on Interactive 3D Graphics, ACM, 2015, 135- p.Conference paper (Refereed)
  • 41.
    Goswami, Prashant
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Eliasson, André
    Franzén, Pontus
    Implicit Incompressible SPH on the GPU2015In: Proceedings of Workshop on Virtual Reality Interaction and Physical Simulation (VRIPHYS), Eurographics - European Association for Computer Graphics, 2015Conference paper (Refereed)
    Abstract [en]

    This paper presents CUDA-based parallelization of implicit incompressible SPH (IISPH) on the GPU. Along with the detailed exposition of our implementation, we analyze various components involved for their costs. We show that our CUDA version achieves near linear scaling with the number of particles and is faster than the multi-core parallelized IISPH on the CPU. We also present a basic comparison of IISPH with the standard SPH on GPU.

  • 42.
    Goswami, Prashant
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Neyret, Fabrice
    Univ. Grenoble, FRA.
    Real-time landscape-size convective clouds simulation and rendering2017In: Proceedings of Workshop on Virtual Reality Interaction and Physical Simulation, Eurographics - European Association for Computer Graphics, 2017Conference paper (Refereed)
    Abstract [en]

    This paper presents an efficient, physics-based procedural model for the real-time animation and visualization of cumulusclouds at landscape size. We couple a coarse Lagrangian model ofair parcelswith a procedural amplification using volumetricnoise. Our Lagrangian model draws an aerologyi.e.,the atmospheric physics of hydrostatic atmosphere with thermodynamicstransforms, augmented by a model of mixing between parcels and environment. In addition to the particle-particle interactions,we introduce particle-implicit environment interactions. In contrast to the usual fluid simulation, we thus do not need to samplethe transparent environment, a key property for real-time efficiency and scalability to large domains. Inheriting from the high-level physics of aerology, we also validate our simulation by comparing it to predictive diagrams, and we show how the user caneasily control key aspects of the result such as the cloud base and top altitude. Our model is thus fast, physical and controllable.

  • 43.
    Grahn, Alexander
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    An Image and Processing Comparison Study of Antialiasing Methods2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Context. Aliasing is a long standing problem in computer graphics. It occurs as the graphics card is unable to sample with an infinite accuracy to render the scene which causes the application to lose colour information for the pixels. This gives the objects and the textures unwanted jagged edges. Post-processing antialiasing methods is one way to reduce or remove these issues for real-time applications.

    Objectives. This study will compare two popular post-processing antialiasing methods that are used in modern games today, i.e., Fast approximate antialiasing (FXAA) and Submorphological antialiasing (SMAA). The main aim is to understand how both method work and how they perform compared to the other.

    Methods. The two methods are implemented in a real-time application using DirectX 11.0. Images and processing data is collected, where the processing data consists of the updating frequency of the rendering of screen known as frames per second (FPS), and the elapsed time on the graphics processing unit(GPU).

    Conclusions. FXAA shows difficulties in handling diagonal edges well but show only minor graphical artefacts in vertical and horizontal edges. The method can produce unwanted blur along edges. The edge pattern detection in SMAA makes it able to handle all directions well. The performance results conclude that FXAA do not lose a lot of FPS and is quick. FXAA is at least three times faster than SMAA on the GPU.

  • 44.
    Grelsson, David
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Tile Based Procedural Terrain Generation in Real-Time: A Study in Performance2014Student thesis
    Abstract [en]

    Context. Procedural Terrain Generation refers to the algorithmical creation of terrains with limited or no user input. Terrains are an important piece of content in many video games and other forms of simulations. Objectives. In this study a tile-based approach to creating endless terrains is investigated. The aim is to find if real-time performance is possible using the proposed method and possible performance increases from utilization of the GPU. Methods. An application that allows the user to walk around on a seemingly endless terrain is created in two versions, one that exclusively utilizes the CPU and one that utilizes both CPU and GPU. An experiment is then conducted that measures performance of both versions of the application. Results. Results showed that real-time performance is indeed possible for smaller tile sizes on the CPU. They also showed that the application benefits significantly from utilizing the GPU. Conclusions. It is concluded that the tile-based approach works well and creates a functional terrain. However performance is too poor for the technique to be utilized in e.g. a video game.

  • 45.
    Guo, Yang
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Bai, Guohua
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    A General Architecture For Developing A Sustainable Elderly Care E-Health System2014In: International Journal of Information Technology and Business Management(JITBM) , ISSN 2304-0777, Vol. 027, no 1, 95-101 p.Article in journal (Refereed)
    Abstract [en]

    Based on some identified problems and challenges to the current healthcare system, this paper proposes architecture for developing e-health system to meet the challenges and resolve some problems. The architecture is based on a solid theoretical model of human activity, and it has properties such as sustainability, generality, and expandability. We demonstrate the properties of the architecture through an ongoing research project. We concluded that this architecture can be widely used to integrate various small scale applications of e-health systems and to resolve some current design problems such as interoperability and knowledge sharing.

  • 46.
    Guo, Yang
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Bai, Guohua
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    An IOT Architecture For Home-based Elderly Healthcare2014Conference paper (Refereed)
    Abstract [en]

    The problem of providing effective and appropriate healthcare to elderly and disable people home has been increasingly talked around. Information and communication technology (ICT) is believed to enable home healthcare management to mitigate some problems. This paper is to contribute IoT (Internet of things) architecture to achieve connectivity with the patient, sensors and everything around it. A four-level model including ‘personal-family-community-hospital’ is constructed in order to provide complete and intelligent health management services to elderly home, which provides sustainable healthcare service for elderly people. This new solution makes both the elderly life easier and the healthcare process more effective.

  • 47.
    Guo, Yang
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Yao, Yong
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Bai, Guohua
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    On Enhancement of Inter-Activity for Knowledge Sharing in eHealth2016In: 2016 INTERNATIONAL CONFERENCE ON COMMUNICATIONS (COMM 2016), IEEE, 2016, 247-250 p.Conference paper (Refereed)
    Abstract [en]

    Today, knowledge sharing raises as an important issue that challenges for the eHealth management system. It becomes one of the most demanding applications with references to the dynamic inter-activities among different health actors and the complex data structures involved in this application. In this paper, we suggest an activity theory based ontology model to scientifically represent various health actors in the eHealth system. The goal of the suggest model is to enhance the inter activities among these health actors for the efficient knowledge sharing purposes. We also develop a prototype software system based on the suggested ontology model. The survey results collected from the system users show the feasibility of the developed software system.

  • 48.
    Gustav, During
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Evaluating game experience when using augment reality: In real time strategy games2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Context. Augmented reality (AR) is a technology that uses the camera to display what is seen on the screen and adds digital informationover the picture. This study analyses how augmented reality mightaect game experience when applied to real time strategy games.

    Objectives. Evaluate the available development tools, to implementthe game prototype and the AR interaction. Then develop interactive methods for AR and traditional version. Create a basic articialintelligence, design the experiment to evaluate game experience, completion time and score.

    Methods. The experiment were executed after implementation of thegame, in this the participant played both the traditional and augmented reality version of the same game. Before starting to play participant lled out a pre inquiry about their previous experience withgames, tablets and computers. After playing they answered a postinquiry with questions about the game. The comparing experimentwas conducted with several participants in a controlled environment.

    Results. The results show that most participants thought that theAR version had an interesting mechanic and that the game experiencehad been enhanced when compared to the PC version. However theparticipants thought the controls where better on the PC.

    Conclusions. The results indicated that the game experience basedon player performance, decreased in the AR version and that the controls were better on the PC. The participants thought that the PCversion was a little easier to play. However about 71% of the participants thought the game experience on the AR version was interestingbecause they could move around while playing. The most enjoyableversion of the game varied a lot between participants, having a slightpreference for the PC version of the game. However, participantsmanifested an interest in playing a sequel of the game in the AR version.

  • 49.
    Gustavsson, David
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Interaction with a 3D modeling tool through a gestural interface: An Evaluation of Effectiveness and Quality2014Student thesis
    Abstract [en]

    Context. Gestural interfaces involves the ability of technology identifying and recognizing human body language and then interpret this into commands. This is usually used to ease our everyday life, but also to increase usability in for example mobile phones. Objectives. In this study the use of a gestural interface is evaluated as an interaction method to facilitate the introduction of new and novice users to 3D modeling tools. A gestural interface might reduce the modeling time without making an impact on the quality of the result. Methods. A gestural interface is designed and implemented based on previous research regarding gestural interfaces. Time and quality results are gathered through an experiment where participants are to complete a set of tasks in the modeling tool Autodesk Maya that relates to modeling. These tasks are executed in both the implemented gestural interfaces as well as the standard interface of Autodesk Maya. User experience is also gathered through the use of a SUS questionnaire. Results. 17 participants took part in the experiment. Each participant generated time and quality results for each task of the experiment for each interface. For each interface the user experience was recorded through a SUS questionnaire. Conclusions. The results showed that the use of a gestural interface did increase the modeling time for the users, indicating that the use of a gestural interface was not preferable as an interaction medium. The results did show that the time difference between the interfaces was reduced for each completed task, indicating that the gestural interface might have an increase in learnability of the software. The same indication were given from the SUS questionnaire. Also, the results did not show any impact on the quality.

  • 50.
    Gustavsson, Ingvar
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Applied Signal Processing.
    Zackrisson, Johan
    Blekinge Institute of Technology, Faculty of Engineering, Department of Applied Signal Processing.
    Lundberg, Jenny
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    VISIR work in progress2014Conference paper (Refereed)
    Abstract [en]

    The VISIR (Virtual Instrument Systems in Reality) Open Lab Platform is an architecture that enable universities, secondary schools, and other organizations to open instructional laboratories for remote access with preserved context. VISIR emanates from a feasibility study made in 1999 at BTH (Blekinge Institute of Technology) in Sweden. Today, VISIR laboratories are online at seven universities globally where thousands of students can work and conduct most experiments that can be performed on a solderless breadboard remotely without any risk of being harmed. IAOE (International Association of Online Engineering has organized SIG VISIR a Special Interest Group for VISIR. Further development of the platform is carried out in this Community. This paper is about work in progress especially at BTH.

123 1 - 50 of 133
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf