hig.sePublications
Change search
Refine search result
123 1 - 50 of 104
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard-cite-them-right
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • sv-SE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • de-DE
  • 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
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Andrée, Martin
    et al.
    Lantmäteriet.
    Larsson, Karolina
    KLM; Stockholms stad.
    Nordqvist Darell, Fanny
    Stockholms stad.
    Malm, Linus
    Tyréns.
    Tullberg, Odd
    WSP.
    Wallberg, Ann
    JM.
    Norsell, Johan
    NAI Svefa.
    Paasch, Jesper M.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Paulsson, Jenny
    Kungliga Tekniska Högskolan, Stockholm.
    Slutrapport för projektet Smart planering för byggande: Delprojekt 3 - BIM som informationsstöd för 3D fastighetsbildning2018Report (Other academic)
    Abstract [sv]

    Samhällsbyggnadsprocessen behöver utvecklas och bli smartare, öppnare och mer effektiv för ett ökat bostadsbyggande. En digitalisering av samhällsbyggnadsprocessen kan ge ett effektivare samarbete mellan kommun, fastighetsägare, byggherrar, medborgare, näringsliv och myndigheter.Vid bildande av tredimensionellt avgränsade fastigheter eller fastighetsutrymmen (3D-fastigheter) behöver gränsernas läge redovisas både verbalt och i kartor och ritningar, detsamma gäller berörda rättigheter. Det är idag ofta svårt att korrekt redovisa en 3D-volym med enbart dagens pappersritningar och även svårt att läsa en registerkarta i 2D med fastigheter och rättigheter beslutade i 3D. Beslutsunderlagen i fastighetsbildnings-processen behöver bli mer enhetliga och entydiga samt fastighetsinformationen behöver bli återanvändningsbar i hela samhällsbyggnadsprocessen.I detta projekt har vi studerat informationsbehovet i de olika tidpunkterna under fastighetsbildningsprocessen för 3D-fastigheter med fokus på vem som är ansvarig för att tillhandahålla informationsunderlag för att identifiera krav på utformning av 3D-modeller (t.ex BIM) och 3D-stöd för fastighetsbildning.Internationellt finns det ett stort intresse och många frågeställningar gällande samspelet mellan BIM och Fastighetsinformation; det är däremot ganska få fall som har identifierats där man har arbetat praktiskt med BIM i relation till redovisning av 3D-fastigheter.Projektethar även tittat på behov av visualisering och tillhandahållande av fastighetsinformation i 3D, hur informationen bör utformas för att kunna tolkas korrekt samt nyttjas vidare av andra aktörer i samhällsbyggnadsprocessen.Slutsatsen i projektetär att en framtida arbetsmodell där man i samband med myndighetsutövningen för fastighetsbildning samverkar med stöd av BIM och geografisk information i ärendehandläggningen kan ge stora effekter på både myndighetens effektivitet och i ärendeutövningen och för förståelsen av fastighetbildningsbeslutet hos samtliga intressenter i processen. För att det arbete som genomförts i denna utredning skall få genomslag i den dagliga verksamheten rekommenderar vibland annatatt de statliga och kommunala lantmäterimyndigheterna arbetar vidare med att utveckla arbetsprocessen och rekommendationerna för 3D-fastighetsbildning baserat på resultatet från detta projekt och redan i dagens modell efterfrågar att man i handläggningsprocessen kan arbeta BIM-baserat även om kommande beslutshandlingar under en övergångsperiod fortfarande kommer att vara baserade på ritningsbilagor i 2D.

    Download full text (pdf)
    fulltext
  • 2.
    Andrée, Martin
    et al.
    Sandviken kommun.
    Larsson, Karolina
    Stockholms stad.
    Paasch, Jesper M.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Paulsson, Jenny
    Kungliga Tekniska Högskolan (KTH).
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Smarta plan-, bygg- och förvaltningsprocesser över hela livscykeln: AP3 Visualisering av 3D-fastigheter2020Report (Other academic)
    Download full text (pdf)
    fulltext
  • 3.
    Andrée, Martin
    et al.
    Lantmäteriet.
    Paasch, Jesper M.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Paulsson, Jenny
    Kungliga Tekniska Högskolan.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    BIM and 3D property visualisation2018In: FIG Congress 2018: Proceedings, 2018, article id 9367Conference paper (Other academic)
    Abstract [en]

    The concept of 3D property has only existed a short period of time in Sweden, being introduced in 2004 and expanded in 2009 by the addition of condominium (apartment) ownership. It is therefore a rather new form of land management, and the demand for 3D property formation has not been as high as initially expected. There is however an increased interest in 3D property and ownership apartments today, also as being part of the nation’s geospatial infrastructure together with related 3D information for e.g. buildings, utility networks and other features. An effective management of 3D property is depending on, among other things, visualization, representation and storage of 3D real property data, such as legal boundaries and real property rights. There are at present a number of ongoing 3D development and research projects focusing on visualization and standardization of 3D cadastral boundaries. They are part of the national "Smart Built Environment" development and research program, which includes the use of BIM in the (future) 3D property formation process with focus on visualization of 3D real property and condominiums, and specification of requirements and evaluation of 3D digital real property information created and managed in the processes.

    This paper presents the preliminary results of the working group on visualization of 3D boundaries in the project "Smart planning, construction and management processes throughout the life cycle". The aim is to test the results produced in the project "Information for planning, real property formation and building permission", working group "BIM for 3D property formation." The purpose of this working group is to set the requirements for and evaluate the test bed for 3D property information. The focus is on visualization of 3D property and ownership apartments. The proposed model for digitization and visualization of 3D property formation will be tested in a test bed environment. A pilot case from the Stockholm area is then used in the test bed to see how it could work in practice.

    The expected outcome is recommendations for the exchange of documentation and other digital information in 3D processes, the visualization of legal boundaries for stakeholders, registration of legal 3D objects in the Swedish national real property register and how to communicate 3D models to right holders/stakeholders for 3D property and condominiums and the property market, as well as suggestions for a homogeneous, effective and digital flow of 3D information to be used by actors and other stakeholders in the property formation, planning and building processes.

    Download full text (pdf)
    fulltext
  • 4.
    Aslani, Mohammad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Mesgari, Mohammad Saadi
    Division of Visual Information and Interaction, Department of Information Technology, Uppsala University, Uppsala, Sweden.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science. Faculty of Geodesy and Geomatics Engineering, K. N. Toosi University of Technology, Tehran, Iran.
    Wiering, Marco
    Institute of Artificial Intelligence and Cognitive Engineering, University of Groningen, Groningen, Netherlands.
    Developing adaptive traffic signal control by actor-critic and direct exploration methods2019In: Proceedings of the Institution of Civil Engineers: Transport, ISSN 0965-092X, E-ISSN 1751-7710, Vol. 172, no 5, p. 289-298Article in journal (Refereed)
    Abstract [en]

    Designing efficient traffic signal controllers has always been an important concern in traffic engineering. This is owing to the complex and uncertain nature of traffic environments. Within such a context, reinforcement learning has been one of the most successful methods owing to its adaptability and its online learning ability. Reinforcement learning provides traffic signals with the ability automatically to determine the ideal behaviour for achieving their objective (alleviating traffic congestion). In fact, traffic signals based on reinforcement learning are able to learn and react flexibly to different traffic situations without the need of a predefined model of the environment. In this research, the actor-critic method is used for adaptive traffic signal control (ATSC-AC). Actor-critic has the advantages of both actor-only and critic-only methods. One of the most important issues in reinforcement learning is the trade-off between exploration of the traffic environment and exploitation of the knowledge already obtained. In order to tackle this challenge, two direct exploration methods are adapted to traffic signal control and compared with two indirect exploration methods. The results reveal that ATSC-ACs based on direct exploration methods have the best performance and they consistently outperform a fixed-time controller, reducing average travel time by 21%.

  • 5.
    Aslani, Mohammad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science. Uppsala universitet.
    A fast instance selection method for support vector machines in building extraction2020In: Applied Soft Computing, ISSN 1568-4946, E-ISSN 1872-9681, Vol. 97, no B, article id 106716Article in journal (Refereed)
    Abstract [en]

    Training support vector machines (SVMs) for pixel-based feature extraction purposes from aerial images requires selecting representative pixels (instances) as a training dataset. In this research, locality-sensitive hashing (LSH) is adopted for developing a new instance selection method which is referred to as DR.LSH. The intuition of DR.LSH rests on rapidly finding similar and redundant training samples and excluding them from the original dataset. The simple idea of this method alongside its linear computational complexity make it expeditious in coping with massive training data (millions of pixels). DR.LSH is benchmarked against two recently proposed methods on a dataset for building extraction with 23,750,000 samples obtained from the fusion of aerial images and point clouds. The results reveal that DR.LSH outperforms them in terms of both preservation rate and maintaining the generalization ability (classification loss). The source code of DR.LSH can be found in https://github.com/mohaslani/DR.LSH.

    Download full text (pdf)
    fulltext
  • 6.
    Aslani, Mohammad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science. Uppsala universitet.
    A Spatially Detailed Approach to the Assessment of Rooftop Solar Energy Potential based on LiDAR Data2022In: Proceedings of the 8th International Conference on Geographical Information Systems Theory, Applications and Management - GISTAM, ScitePress , 2022, p. 56-63Conference paper (Refereed)
    Abstract [en]

    Rooftop solar energy has long been regarded as a promising solution to cities’ growing energy demand and environmental problems. A reliable estimate of rooftop solar energy facilitates the deployment of photovoltaics and helps formulate renewable-related policies. This reliable estimate underpins the necessity of accurately pinpointing the areas utilizable for mounting photovoltaics. The size, shape, and superstructures of rooftops as well as shadow effects are the important factors that have a considerable impact on utilizable areas. In this study, the utilizable areas and solar energy potential of rooftops are estimated by considering the mentioned factors using a three-step methodology. The first step involves training PointNet++, a deep network for object detection in point clouds, to recognize rooftops in LiDAR data. Second, planar segments of rooftops are extracted using clustering. Finally, areas that receive sufficient solar irradiation, have an appropriate size, and fulfill photovoltaic installation requirements are identified using morphological operations and predefined thresholds. The obtained results show high accuracy for rooftop extraction (93%) and plane segmentation (99%). Moreover, the spatially detailed analysis indicates that 17% of rooftop areas are usable for photovoltaics.

  • 7.
    Aslani, Mohammad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science. Uppsala universitet.
    Automatic identification of utilizable rooftop areas in digital surface models for photovoltaics potential assessment2022In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 306, article id 118033Article in journal (Refereed)
    Abstract [en]

    The considerable potential of rooftop photovoltaics (RPVs) for alleviating the high energy demand of cities has made them a proven technology in local energy networks. Identification of rooftop areas suitable for installing RPVs is of importance for energy planning. Having these suitable areas referred to as utilizable areas greatly assists in a reliable estimate of RPVs energy production. Within such a context, this research aims to propose a spatially detailed methodology that involves (a) automatic extraction of buildings footprint, (b) automatic segmentation of roof faces, and (c) automatic identification of utilizable areas of roof faces for solar infrastructure installation. Specifically, the innovations of this work are a new method for roof face segmentation and a new method for the identification of utilizable rooftop areas. The proposed methodology only requires digital surface models (DSMs) as input, and it is independent of other auxiliary spatial data to become more functional. A part of downtown Gothenburg composed of vegetation and high-rise buildings with complex shapes was selected to demonstrate the methodology performance. According to the experimental results, the proposed methodology has a high success rate in building extraction (about 95% correctness and completeness) and roof face segmentation (about 85% completeness and correctness). Additionally, the results suggest that the effects of roof occlusions and roof superstructures are satisfactorily considered in the identification of utilizable rooftop areas. Thus, the methodology is practically effective and relevant for the detailed RPVs assessments in arbitrary urban regions where only DSMs are accessible.

    Download full text (pdf)
    fulltext
  • 8.
    Aslani, Mohammad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science. Uppsala universitet.
    Efficient and decision boundary aware instance selection for support vector machines2021In: Information Sciences, ISSN 0020-0255, E-ISSN 1872-6291, Vol. 577, p. 579-598Article in journal (Refereed)
    Abstract [en]

    Support vector machines (SVMs) are powerful classifiers that have high computational complexity in the training phase, which can limit their applicability to large datasets. An effective approach to address this limitation is to select a small subset of the most representative training samples such that desirable results can be obtained. In this study, a novel instance selection method called border point extraction based on locality-sensitive hashing (BPLSH) is designed. BPLSH preserves instances that are near the decision boundaries and eliminates nonessential ones. The performance of BPLSH is benchmarked against four approaches on different classification problems. The experimental results indicate that BPLSH outperforms the other methods in terms of classification accuracy, preservation rate, and execution time. The source code of BPLSH can be found in https://github.com/mohaslani/BPLSH. 

    Download full text (pdf)
    fulltext
  • 9.
    Aslani, Mohammad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science. Uppsala universitet.
    Rooftop segmentation and optimization of photovoltaic panel layouts in digital surface models2023In: Computers, Environment and Urban Systems, ISSN 0198-9715, E-ISSN 1873-7587, Vol. 105, article id 102026Article in journal (Refereed)
    Abstract [en]

    Rooftop photovoltaic panels (RPVs) are being increasingly used in urban areas as a promising means of achieving energy sustainability. Determining proper layouts of RPVs that make the best use of rooftop areas is of importance as they have a considerable impact on the RPVs performance in efficiently producing energy. In this study, a new spatial methodology for automatically determining the proper layouts of RPVs is proposed. It aims to both extract planar rooftop segments and identify feasible layouts with the highest number of RPVs in highly irradiated areas. It leverages digital surface models (DSMs) to consider roof shapes and occlusions in placing RPVs. The innovations of the work are twofold: (a) a new method for plane segmentation, and (b) a new method for optimally placing RPVs based on metaheuristic optimization, which best utilizes the limited rooftop areas. The proposed methodology is evaluated on two test sites that differ in urban morphology, building size, and spatial resolution. The results show that the plane segmentation method can accurately extract planar segments, achieving 88.7% and 99.5% precision in the test sites. In addition, the results indicate that complex rooftops are adequately handled for placing RPVs, and overestimation of solar energy potential is avoided if detailed analysis based on panel placement is employed.

    Download full text (pdf)
    fulltext
  • 10.
    Aslani, Mohammad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Solar Energy Assessment: From Rooftop Extraction to Identifying Utilizable Areas2023In: Geographical Information Systems Theory, Applications and Management, 7th International Conference, GISTAM 2021, Virtual Event, April 23–25, 2021, and 8th International Conference, GISTAM 2022, Virtual Event, April 27-29, 2022, Revised Selected Papers / [ed] Grueau, C., Laurini, R., Ragia, L., Springer , 2023, p. 102-115Conference paper (Refereed)
    Abstract [en]

    Rooftop photovoltaics have been acknowledged as a critical component in cities’ efforts to reduce their reliance on fossil fuels and move towards energy sustainability. Identifying rooftop areas suitable for installing rooftop photovoltaics-referred to as utilizable areas-is essential for effective energy planning and developing policies related to renewable energies. Utilizable areas are greatly affected by the size, shape, superstructures of rooftops, and shadow effects. This study estimates utilizable areas and solar energy potential of rooftops by considering the mentioned factors. First, rooftops are extracted from LiDAR data by training PointNet++, a neural network architecture for processing 3D point clouds. The second step involves extracting planar segments of rooftops using a combination of clustering and region growing. Finally, utilizable areas of planar segments are identified by removing areas that do not have a suitable size and do not receive sufficient solar irradiation. Additionally, in this step, areas reserved for accessibility to photovoltaics are removed. According to the experimental results, the methods have a high success rate in rooftop extraction, plane segmentation, and, consequently, estimating utilizable areas for photovoltaics.

  • 11.
    Aslani, Mohammad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science. Faculty of Geodesy and Geomatics Engineering, K. N. Toosi University of Technology, Tehran, Iran.
    Mohammad Saadi, Mesgari
    Division of Visual Information and Interaction, Department of Information Technology, Uppsala University, Uppsala, Sweden.
    Wiering, Marco A.
    Institute of Artificial Intelligence and Cognitive Engineering, University of Groningen, Groningen, Netherlands.
    Traffic signal optimization through discrete and continuous reinforcement learning with robustness analysis in downtown Tehran2018In: Advanced Engineering Informatics, ISSN 1474-0346, E-ISSN 1873-5320, Vol. 38, p. 639-655Article in journal (Refereed)
    Abstract [en]

    Traffic signal control plays a pivotal role in reducing traffic congestion. Traffic signals cannot be adequately controlled with conventional methods due to the high variations and complexity in traffic environments. In recent years, reinforcement learning (RL) has shown great potential for traffic signal control because of its high adaptability, flexibility, and scalability. However, designing RL-embedded traffic signal controllers (RLTSCs) for traffic systems with a high degree of realism is faced with several challenges, among others system disturbances and large state-action spaces are considered in this research.

    The contribution of the present work is founded on three features: (a) evaluating the robustness of different RLTSCs against system disturbances including incidents, jaywalking, and sensor noise, (b) handling a high-dimensional state-action space by both employing different continuous state RL algorithms and reducing the state-action space in order to improve the performance and learning speed of the system, and (c) presenting a detailed empirical study of traffic signals control of downtown Tehran through seven RL algorithms: discrete state Q-learning(λ" role="presentation">), SARSA(λ" role="presentation">), actor-critic(λ" role="presentation">), continuous state Q-learning(λ" role="presentation">), SARSA(λ" role="presentation">), actor-critic(λ" role="presentation">), and residual actor-critic(λ" role="presentation">).

    In this research, first a real-world microscopic traffic simulation of downtown Tehran is carried out, then four experiments are performed in order to find the best RLTSC with convincing robustness and strong performance. The results reveal that the RLTSC based on continuous state actor-critic(λ" role="presentation">) has the best performance. In addition, it is found that the best RLTSC leads to saving average travel time by 22% (at the presence of high system disturbances) when it is compared with an optimized fixed-time controller.

  • 12.
    Aslani, Mohammad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science. Division of Visual Information and Interaction, Department of Information Technology, Uppsala University, Uppsala, Sweden.
    Wiering, Marco
    Institute of Artificial Intelligence and Cognitive Engineering, University of Groningen, Groningen, the Netherlands.
    Continuous residual reinforcement learning for traffic signal control optimization2018In: Canadian journal of civil engineering (Print), ISSN 0315-1468, E-ISSN 1208-6029, Vol. 45, no 8, p. 690-702Article in journal (Refereed)
    Abstract [en]

    Traffic signal control can be naturally regarded as a reinforcement learning problem. Unfortunately, it is one of the most difficult classes of reinforcement learning problems owing to its large state space. A straightforward approach to address this challenge is to control traffic signals based on continuous reinforcement learning. Although they have been successful in traffic signal control, they may become unstable and fail to converge to near-optimal solutions. We develop adaptive traffic signal controllers based on continuous residual reinforcement learning (CRL-TSC) that is more stable. The effect of three feature functions is empirically investigated in a microscopic traffic simulation. Furthermore, the effects of departing streets, more actions, and the use of the spatial distribution of the vehicles on the performance of CRL-TSCs are assessed. The results show that the best setup of the CRL-TSC leads to saving average travel time by 15% in comparison to an optimized fixed-time controller.

  • 13.
    Blomqvist, Sven
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Public Health and Sport Science, Sports Science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science. Uppsala universitet.
    Engström, Maria
    University of Gävle, Faculty of Health and Occupational Studies, Department of Caring Science, Caring Science.
    Using augmented reality technology for balance training in the older adults: a feasibility pilot study2021In: BMC Geriatrics, ISSN 1471-2318, E-ISSN 1471-2318, Vol. 21, article id 144Article in journal (Refereed)
    Abstract [en]

    Background: Impaired balance leading to falls is common in the older adults, and there is strong evidence that balance training reduces falls and increases independence. Reduced resources in health care will result in fewer people getting help with rehabilitation training. In this regard, the new technology augmented reality (AR) could be helpful. With AR, the older adults can receive help with instructions and get feedback on their progression in balance training. The purpose of this pilot study was to examine the feasibility of using AR-based visual-interactive tools in balance training of the older adults.; Methods: Seven older adults (66-88 years old) with impaired balance trained under supervision of a physiotherapist twice a week for six weeks using AR-based visual-interactive guidance, which was facilitated through a Microsoft HoloLens holographic display. Afterwards, participants and physiotherapists were interviewed about the new technology and their experience of the training. Also, fear of falling and balance ability were measured before and after training.; Results: Five participants experienced the new technology as positive in terms of increased motivation and feedback. Experiences were mixed regarding the physical and technical aspects of the HoloLens and the design of the HoloLens application. Participants also described issues that needed to be further improved, for example, the training program was difficult and monotonous. Further, the HoloLens hardware was felt to be heavy, the application's menu was difficult to control with different hand manoeuvres, and the calibration took a long time. Suggestions for improvements were described. Results of the balance tests and self-assessment instruments indicated no improvements in balance performance after AR training.; Conclusions: The study showed that training with the new technology is, to some extent, feasible for the older adults, but needs further development. Also, the technology seemed to stimulate increased motivation, which is a prerequisite for adherence to training. However, the new technology and training requires further development and testing in a larger context.

    Download full text (pdf)
    fulltext
  • 14.
    Chandel, Kuhelee
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Åhlén, Julia
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science. Department of Information Technology, Uppsala University.
    Augmented Reality and Indoor Positioning in Context of Smart Industry: A Review2022In: Management and Production Engineering Review, ISSN 2080-8208, E-ISSN 2082-1344, Vol. 13, no 4, p. 72-87Article, review/survey (Refereed)
    Abstract [en]

    Presently, digitalization is causing continuous transformation of industrial processes. However, it does pose challenges like spatially contextualizing data from industrial processes. There are various methods for calculating and delivering real-time location data. Indoor positioning systems (IPS) are one such method, used to locate objects and people within buildings. They have the potential to improve digital industrial processes, but they are currently under utilized. In addition, augmented reality (AR) is a critical technology in today’s digital industrial transformation. This article aims to investigate the use of IPS and AR in manufacturing, the methodologies and technologies employed, the issues and limitations encountered, and identify future research opportunities. This study concludes that, while there have been many studies on IPS and navigation AR, there has been a dearth of research efforts in combining the two. Furthermore, because controlled environments may not expose users to the practical issues they may face, more research in a real-world manufacturing environment is required to produce more reliable and sustainable results

    Download full text (pdf)
    fulltext
  • 15.
    Chandel, Kuhelee
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Åhlén, Julia
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science. University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Evaluating the Tracking Abilities of Microsoft HoloLens-1 for Small-Scale Industrial Processes2023Conference paper (Refereed)
    Abstract [en]

    This study evaluates the accuracy of Microsoft HoloLens (Version 1) for small-scale industrial activities, comparingits measurements to ground truth data from a Kuka Robotics arm. Two experiments were conducted to assess its positiontracking capabilities, revealing that the HoloLens device is effective for measuring the position of dynamic objects with smalldimensions. However, its precision is affected by the velocity of the trajectory and its position within the device's field of view.While the HoloLens device may be suitable for small-scale tasks, its limitations for more complex and demanding applicationsrequiring high precision and accuracy must be considered. The findings can guide the use of HoloLens devices in industrialapplications and contribute to the development of more effective and reliable position-tracking systems.

    Download full text (pdf)
    abstract
  • 16.
    Ericsson, Martin
    et al.
    Uppsala universitet.
    Hast, Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    A Heterogeneous Cluster framework for Computationally Heavy Visualizations2009In: Proceedings of IADIS Applied Computing 2009, 2009, p. 337-339Conference paper (Refereed)
  • 17.
    Forsberg, Ann-Kristin
    et al.
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Winkler Pettersson, Lars
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Linden, Elisabet
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för inomhusmiljö.
    Sandberg, Mats
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för inomhusmiljö.
    Seipel, Stefan
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    An augmented-reality approach to co-located visual exploration of indoor climate data in real rooms2005In: Indoor Air 2005: Proceedings of the 10th International Conference on Indoor Air Quality and Climate, 2005, p. 2860-2860Conference paper (Other academic)
    Abstract [en]

    We live in two spaces, the visible space and the non-visible but otherwise sensed space. Both spaces must satisfy our needs and there is a relation between them. If parts of the room are too cold this will lead to a restriction of the use of the room. We cannot endure draft for any longer time. Draft caused by a ventilation supply frequently leads to blockage of the supply device, which in turn gives rise to a reduction of the ventilation rate. The final result may be a deterioration of the air quality. Therefore, to be able to guarantee the air quality it is necessary to make the invisible thermal climate visible. In this paper a novel method based on Augmented Reality for presenting die thermal climate is presented and discussed. The data, e.g. temperatures and velocities, are shown on a lightweight display. Several people can walk around in a real room and see on a screen where the hot and/or cold spots may appear. Different ventilation solutions could in that way be compared in a dialogue between different actors in the building process.

  • 18. Forsell, C
    et al.
    Seipel, Stefan
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Lind, M
    Simple 3D Glyphs for Spatial Multivariate Data2005In: Proceedings of the IEEE Symposium on Information Visualization – Infovis 2005, 2005, p. 119-124Conference paper (Other academic)
    Abstract [en]

    We present an effort to evaluate the possible utility of a new type of 3D glyphs intended for visualizations of multivariate spatial data. They are based on results from vision research suggesting that our perception of metric 3D structure is distorted and imprecise relative to the actual scene before us (e.g., [1]); only a class of qualitative properties of the scene is perceived with accuracy. These properties are best characterized as being invariant over affine but not Euclidean transformations. They are related, but not identical to, the non-accidental properties (NAPs) described by Lowe [2] on which the notion of geons is based [3]. A large number of possible 3D glyphs for the visualization of spatial data can be constructed using such properties. One group is based on the local sign of surface curvature. We investigated these properties in a visualization experiment. The results are promising and the implications for visualization are discussed.

  • 19. Forsell, C.
    et al.
    Seipel, Stefan
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Lind, M.
    Surface Glyphs for Efficient Visualization of Multivariate Data2006In: Information Visualization, ISSN 1473-8716, E-ISSN 1473-8724, Vol. 5, no 2, p. 112-124Article in journal (Refereed)
    Abstract [en]

    We present a first effort to evaluate the possible utility of a new type of surface glyphs intended for visualizations of multivariate spatial data. The glyphs are based on results from vision research suggesting that our perception of metric 3D structure is distorted and imprecise relative to the actual scene before us; only a class of qualitative properties of the scene is perceived with accuracy. These properties are best characterized as being invariant over affine but not Euclidean transformations. A large number of possible 3D glyphs for the visualization of spatial data can be constructed using such properties. One group of such glyphs is based on the local sign of surface curvature. We investigated this group in two visualization experiments. The results show that available sources of 3D structural information were sufficient for our subjects to make fast and accurate judgments. Some implications for visualization are also discussed.

  • 20.
    Hast, Anders
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Ericsson, Martin
    UPPMAX, Uppsala University, Uppsala, Sweden .
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Multiscale Texture Synthesis and Colourization of Greyscale Textures2010In: 18th International Conference in Central Europe on Computer Graphics, Visualization and Computer Vision, WSCG 2010 - In Co-operation with EUROGRAPHICS: Full Papers Proceedings, Plzen: Union Agency Science Press , 2010, p. 55-61Conference paper (Refereed)
    Abstract [en]

    The main idea presented herein is to use a multiscale texture synthesis approach in order to both colourize and upscale greyscale textures. Such textures can be vintage photos to be used in archaeological or urban 3D visualizations and obviously the colour needs to be reconstructed some way. Due to limited quality, walls etc in such 3D visualizations will appear either pixelized or blurry when the viewer approaches them on a close distance. The latter if some kind of interpolation technique is being used to reduce the pixelization. The low resolution greyscale texture and a high resolution coloured texture is used for the colourization and upscaling, which will produce a colour version of the greyscale texture with 4 times higher resolution in each upscale step. The novel idea is to use multiscale texture synthesis in HSV space for the first upscale in order to create a RGB colour image for subsequent upscaling, using either ordinary RGB multiscale texture synthesis or continue using HSV multiscale texture synthesis. These two main approaches will be compared and discussed.

  • 21.
    Hast, Anders
    et al.
    Uppsala universitet.
    Jenke, Peter
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science. Uppsala universitet.
    Shortest diagonal triangulation of convex layers2013In: Proceedings of the IASTED International Conference on Signal Processing, Pattern Recognition and Applications, SPPRA 2013, 2013, p. 424-430Conference paper (Refereed)
    Abstract [en]

    One problem in the field of computational geometry is the triangulation of convex layers. The rotating caliper algorithm is an alternative to the constrained Delaunay triangulation method. We present an improved triangulation algorithm, which gives a mesh quality close to that of the Constrained Delaunay but substantially faster. Each layer will be connected to the neighboring layer by edges and from the two vertices constituting an edge the proposed algorithm will select the shortest diagonal to its next neighbors in the polygonal chain on the other side, i.e. from the outer layer to the inner layer or vice versa. We discuss quality issues regarding the rotating caliper method and some improvements to it, as well as how a Constrained Delaunay can be efficiently implemented for convex layers.

  • 22.
    Hast, Anders
    et al.
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Wesslén, Daniel
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Seipel, Stefan
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Improved Diffuse Anisotropic Shading2004In: Proceedings of the Annual SIGRAD Conference, 2004, p. 57-58Conference paper (Refereed)
  • 23.
    Humble, Niklas
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Boustedt, Jonas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Holmgren, Hanna
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Milutinovic, Goran
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Östberg, Ann-Sofie
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Cheaters or AI-Enhanced Learners: Consequences of ChatGPT for Programming Education2023In: Electronic Journal of e-Learning, E-ISSN 1479-4403Article in journal (Refereed)
    Abstract [en]

    Artificial Intelligence (AI) and related technologies have a long history of being used in education for motivating learners and enhancing learning. However, there have also been critiques for a too uncritical and naïve implementation of AI in education (AIED) and the potential misuse of the technology. With the release of the virtual assistant ChatGPT from OpenAI, many educators and stakeholders were both amazed and horrified by the potential consequences for education. One field with a potential high impact of ChatGPT is programming education in Computer Science (CS), where creating assessments has long been a challenging task due to the vast amount of programming solutions and support on the Internet. This now appears to have been made even more challenging with ChatGPT’s ability to produce both complex and seemingly novel solutions to programming questions. With the support of data collected from interactions with ChatGPT during the spring semester of 2023, this position paper investigates the potential opportunities and threats of ChatGPT for programming education, guided by the question: What could the potential consequences of ChatGPT be for programming education? This paper applies a methodological approach inspired by analytic autoethnography to investigate, experiment, and understand a novel technology through personal experiences. Through this approach, the authors have documented their interactions with ChatGPT in field diaries during the spring semester of 2023. Topics for the questions have related to content and assessment in higher education programming courses. A total of 6 field diaries, with 82 interactions (1 interaction = 1 question + 1 answer) and additional reflection notes, have been collected and analysed with thematic analysis. The study finds that there are several opportunities and threats of ChatGPT for programming education. Some are to be expected, such as that the quality of the question and the details provided highly impact the quality of the answer. However, other findings were unexpected, such as that ChatGPT appears to be “lying” in some answers and to an extent passes the Turing test, although the intelligence of ChatGPT should be questioned. The conclusion of the study is that ChatGPT have potential for a significant impact on higher education programming courses, and probably on education in general. The technology seems to facilitate both cheating and enhanced learning. What will it be? Cheating or AI-enhanced learning? This will be decided by our actions now since the technology is already here and expanding fast.

    Download full text (pdf)
    fulltext
  • 24.
    Humble, Niklas
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Boustedt, Jonas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Holmgren, Hanna
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Milutinovic, Goran
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Östberg, Ann-Sofie
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    The consequences of ChatGPT for programming education: Cheating or AI-enhanced learning?2023In: Symposium on AI Opportunities and Challenges: Education will never be the same again, ACI Academic Conferences International, 2023, Vol. 1, p. 15-16Conference paper (Other academic)
    Abstract [en]

    Artificial Intelligence (AI) and related technologies have a long history of being used in education for motivating learners and enhancing learning. However, there have also been critiques for a too uncritical and naïve implementation of AI in education (AIED) and the potential misuse of the technology. With the release of the virtual assistant ChatGPT from OpenAI, many educators and stakeholders were both amazed and horrified by the potential consequences for education. One field with a potential high impact of ChatGPT is programming education in Computer Science (CS), where assessments have long been challenging due to the vast amount of programming solutions and support on the Internet. This now appears to have been made even more challenging with ChatGPT’s ability to produce both complex and seemingly novel solutions to programming questions. With the support of data collected from interactions with ChatGPT during the spring semester of 2023, a study was conducted where potential opportunities and threats of ChatGPT for programming education were investigated. The question to answer was: What will the consequences be for programming education? 

    The study applied a methodological approach inspired by action research and analytic autoethnography to investigate, experiment and understand a novel technology through personal experiences. Through this approach, the authors have documented their interactions with ChatGPT in field diaries during the spring semester of 2023. Topics for the questions have related to content and assessment in higher education programming courses. A total of 6 field diaries, with 82 interactions (1 interaction = 1 question + 1 answer) and additional reflection notes, have been collected and analysed with thematic analysis. 

    Findings of the study include several opportunities and threats of ChatGPT for programming education. Some are to be expected, such as that the quality of the question and the details provided highly impact the quality of the answer. However, other findings were unexpected, such as that ChatGPT appears to be lying in some answers and to an extent passes the Turing test, although the intelligence of ChatGPT should be questioned. The conclusion of the study is that ChatGPT will have a significant impact on higher education programming courses, and probably on education in general. The technology seems to facilitate both cheating and enhanced learning. What will it be? Cheating or AI-enhanced learning? This will be decided by our actions now since the technology is already here and expanding fast. 

  • 25.
    Jenke, Peter
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Hast, Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    On the quality of point-cloud triangulations based on convex hulls2010In: Proceedings of the Annual SIGRAD Conference 2010, 2010, p. 71-76Conference paper (Refereed)
  • 26. Jensen, N
    et al.
    Seipel, Stefan
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Nejdl, W
    Olbrich, S
    CoVASE - Collaborative Visualization for Constructivist Learning2003In: Designing for Change in Networked Learning Environments, 2003, p. 249-253Conference paper (Other academic)
    Abstract [en]

    The paper specifies CoVASE, a software for teachers to create and view networked learning environments (VE). Students carry out virtual experiments in CoVASE, at the same time and from different places. They use the same tools and work on the same scientific problems as researchers do. Teachers create a motivating, demanding, and authentic interaction between learners and real-world problems, a premise for constructivist learning (CL). CoVASE generates and displays the result of a numerical simulation in parallel of its progress on distributed 3D graphic viewers, steered by users in real-time. VEs mediate communication between users, deictic elements, and display. Researchers and students have evaluated the predecessors of CoVASE with good results. A field study is planned for 2003.

  • 27. Jensen, N
    et al.
    Seipel, Stefan
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    von Voigt, G
    Raasch, S
    Olbrich, S
    Nejdl, W
    Development of a Virtual Laboratory System for Science Education and the Study of Collaborative Action2004In: Proceedings of AACE ED Media Conference 2004, 2004Conference paper (Other academic)
    Abstract [en]

    The paper specifies the development of a toolkit to run synthetic science laboratories. The aim was to facilitate collaborative experimenting for problem-based learning in a virtual lab. The goal was to demonstrate virtual experimenting by use of interactive 3D visualization and simulation. Technology was developed over six years and in part designed in explicit accordance to didactic models. For tests, we built a virtual lab that comprised media tools and complex computer simulations, and we evaluated it with promising results. Students used data from meteorology and experimented together. Generally, they enjoyed using the system and collaborated in a motivated way. We identified which tools they preferred. The paper indicates ways to improve the design of virtual labs by use of our toolkit.

  • 28.
    Kjellin, Andreas
    et al.
    Uppsala University.
    Pettersson, Lars Winkler
    Uppsala university.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Lind, Mats
    Uppsala University.
    Evaluating 2D and 3D Visualizations of Spatiotemporal Information2010In: ACM Transactions on Applied Perception, ISSN 1544-3558, E-ISSN 1544-3965, Vol. 7, no 3, p. 19:1-19:23Article in journal (Refereed)
    Abstract [en]

    Time-varying geospatial data presents some specific challenges for visualization. Here, we report the results of three experiments aiming at evaluating the relative efficiency of three existing visualization techniques for a class of such data. The class chosen was that of object movement, especially the movements of vehicles in a fictitious landscape. Two different tasks were also chosen. One was to predict where three vehicles will meet in the future given a visualization of their past movement history. The second task was to estimate the order in which four vehicles arrived at a specific place. Our results reveal that previous findings had generalized human perception in these situations and that large differences in user efficiency exist for a given task between different types of visualizations depicting the same data. Furthermore, our results are in line with earlier general findings on the nature of human perception of both object shape and scene changes. Finally, the need for new taxonomies of data and tasks based on results from perception research is discussed.

  • 29.
    Kjellin, Andreas
    et al.
    Informationsvetenskap, Uppsala universitet.
    Winkler Pettersson, Lars
    Informationsteknologi, Uppsala universitet.
    Seipel, Stefan
    Informationsvetenskap, Uppsala universitet.
    Lind, Mats
    Informationsvetenskap, Uppsala universitet.
    Different levels of 3D: an evaluation of visualized discrete spatiotemporal data in space-time cubes2010In: Information Visualization, ISSN 1473-8716, E-ISSN 1473-8724, Vol. 9, no 2, p. 152-164Article in journal (Refereed)
    Abstract [en]

    New technologies and techniques allow novel kinds of visualizations and different types of 3D visualizations are constantly developed. We propose a categorization of 3D visualizations and, based on this categorization, evaluate two versions of a space-time cube that show discrete spatiotemporal data. The two visualization techniques used are a head-tracked stereoscopic visualization ('strong 3D') and a static monocular visualization ('weak 3D'). In terms of effectiveness and efficiency the weak 3D visualization is as good as the strong 3D and thus the need for advanced 3D visualizations in these kinds of tasks may not be necessary.

  • 30.
    Koch, Sabine
    et al.
    CMD Center for Human - Computer Studies , Uppsala University, Uppsala, Sweden.
    Wagner, Ina-Veronika
    CMD Center for Human - Computer Studies , Uppsala University, Uppsala, Sweden.
    Seipel, Stefan
    CMD Center for Human - Computer Studies , Uppsala University, Uppsala, Sweden.
    Schneider, Werner
    CMD Center for Human - Computer Studies , Uppsala University, Uppsala, Sweden.
    Controlled Diagnosis-Oriented Enhancement of Automatically Segmented Radiographs in Dentistry1998In: Computer Methods and Programs in Biomedicine, ISSN 0169-2607, E-ISSN 1872-7565, Vol. 57, no 1-2, p. 125-131Article in journal (Refereed)
    Abstract [en]

    A method for controlled diagnosis-oriented enhancement of selected regions of interest in intraoral radiographs is presented. Image enhancement is accomplished by adaptive non-linear grey scale transformation depending on the result of objective quality measurement. In order to assure reliable image duality measurement as well as controlled image enhancement, automatic image segmentation is applied to avoid the influence of disturbing factors (e.g. metallic restorations) on quality measurement and image enhancement. Based on existing a-priori knowledge about object structure and composition of the selected regions of interest in intraoral radiographs, different image segmentation algorithms and image enhancement procedures were developed for different types of diagnosis. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.

  • 31. Kordaß, B.
    et al.
    Gärtner, Ch.
    Söhnel, A.
    Bisler, A.
    Voß, G.
    Bockholt, U.
    Seipel, Stefan
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    The virtual articulator in dentistry: concept and development2002In: Dental Clinics of North America, ISSN 1558-0512, Vol. 46, no 3, p. 493-506Article in journal (Refereed)
    Abstract [en]

    Virtual Reality (VR) technology is one of the most important innovations for research, development, and industrial production. In dentistry, VR technology will be useful in providing better education through simulation and in enhancing working procedures that are conventionally limited, e.g., the mechanical articulator. It is the purpose of this article to present concepts and strategies for a future replacement of the mechanical articulator by a virtual one.

  • 32.
    Lim, Nancy Joy
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Brandt, S. Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science. Division of Visual Information and Interaction, Department of Information Technology, Uppsala University, Uppsala, Sweden.
    Visualisation and evaluation of flood uncertainties based on ensemble modelling2016In: International Journal of Geographical Information Science, ISSN 1365-8816, E-ISSN 1365-8824, Vol. 30, no 2, p. 240-262Article in journal (Refereed)
    Abstract [en]

    This study evaluates how users incorporate visualisation of flood uncertainty information in decision-making. An experiment was conducted where participants were given the task to decide building locations, taking into account homeowners’ preferences as well as dilemmas imposed by flood risks at the site. Two general types of visualisations for presenting uncertainties from ensemble modelling were evaluated: (1) uncertainty maps, which used aggregated ensemble results; and (2) performance bars showing all individual simulation outputs from the ensemble. Both were supplemented with either two-dimensional (2D) or three-dimensional (3D) contextual information, to give an overview of the area.The results showed that the type of uncertainty visualisation was highly influential on users’ decisions, whereas the representation of the contextual information (2D or 3D) was not. Visualisation with performance bars was more intuitive and effective for the task performed than the uncertainty map. It clearly affected users’ decisions in avoiding certain-to-be-flooded areas. Patterns to which the distances were decided from the homeowners’ preferred positions and the uncertainties were similar, when the 2D and 3D map models were used side by side with the uncertainty map. On the other hand, contextual information affected the time to solve the task. With the 3D map, it took the participants longer time to decide the locations, compared with the other combinations using the 2D model.Designing the visualisation so as to provide more detailed information made respondents avoid dangerous decisions. This has also led to less variation in their overall responses.

  • 33.
    Lim, Nancy Joy
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Brandt, S. Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Assessment of spatial-based decisions and user perspectives in utilisation of flood certainty mapsManuscript (preprint) (Other academic)
  • 34.
    Lim, Nancy Joy
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Åhlén, Julia
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Geovisualisation of uncertainty in simulated flood maps2014In: Proceedings of the International Conferences on Interfaces and Human Computer Interaction 2014, Game and Entertainment Technologies 2014 and Computer Graphics, Visualization, Computer Vision and Image Processing 2014 - Part of the Multi Conference on Computer Science and Information Systems, MCCSIS 2014 / [ed] Katherine Blashki and Yingcai Xiao, IADIS Press , 2014, p. 206-214Conference paper (Refereed)
    Abstract [en]

    The paper presents a three-dimensional (3D) geovisualisation model of uncertainties in simulated flood maps that can help communicate uncertain information in the data being used. An entropy-based measure was employed for uncertainty quantification. In developing the model, Visualisation Toolkit (VTK) was utilised. Different data derived from earlier simulation study and other maps were represented in the model. Cartographic principles were considered in the map design. A Graphical User Interface (GUI), which was developed in Tkinter, was also created to further support exploratory data analysis. The resulting model allowed visual identification of uncertain areas, as well as displaying spatial relationship between the entropy and the slope values. This geovisualisation has still to be tested to assess its effectiveness as a communication tool. However, this type of uncertainty visualisation in flood mapping is an initial step that can lead to its adoption in decision-making when presented comprehensively to its users. Thus, further improvement and development is still suggested for this kind of information presentation.

  • 35. Lind, M.
    et al.
    Seipel, Stefan
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Mattiason, C.
    Displaying meta-information in context2001In: Behavior and Information Technology, ISSN 0144-929X, E-ISSN 1362-3001, Vol. 20, no 6, p. 427-432Article in journal (Refereed)
    Abstract [en]

    Very often information exists that would be helpful for process control operators if it could be presented in the context they work in-the process graphics. Examples are instructional material, visualizations of automated sequences, output from knowledge-based systems or simply annotations that one team of operators wants to communicate with another. Several existing distortion techniques were reviewed that would allow the ordinary process graphics to take less space leaving room for additional information. However, these techniques were rejected, mainly because all parts of a process control screen need to be readable at all times. A new technique is proposed and its readability experimentally evaluated with promising results.

  • 36.
    Liu, Fei
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Jonsson, Torsten
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science. Uppsala universitet.
    Evaluation of augmented reality-based building diagnostics using third person perspective2020In: ISPRS International Journal of Geo-Information, ISSN 2220-9964, Vol. 9, no 1, article id 53Article in journal (Refereed)
    Abstract [en]

    Comprehensive user evaluations of outdoor augmented reality (AR) applications in the architecture, engineering, construction and facilities management (AEC/FM) industry are rarely reported in the literature. This paper presents an AR prototype system for infrared thermographic façade inspection and its evaluation. The system employs markerless tracking based on image registration using natural features and a third person perspective (TPP) augmented view displayed on a hand-held smart device. We focus on evaluating the system in user experiments with the task of designating positions of heat spots on an actual façade as if acquired through thermographic inspection. User and system performance were both assessed with respect to target designation errors. The main findings of this study show that positioning accuracy using this system is adequate for objects of the size of one decimeter. After ruling out the system inherent errors, which mainly stem from our application-specific image registration procedure, we find that errors due to a human’s limited visual-motoric and cognitive performance, which have a more general implication for using TPP AR for target designation, are only a few centimeters.

  • 37.
    Liu, Fei
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Detection of Façade Regions in Street View Images from Split-and-Merge of Perspective Patches2014In: Journal of Image and Graphics, ISSN 2301-3699, Vol. 2, no 1, p. 8-14Article in journal (Refereed)
    Abstract [en]

    Identification of building façades from digital images is one of the central problems in mobile augmented reality (MAR) applications in the built environment. Directly analyzing the whole image can increase the difficulty of façade identification due to the presence of image portions which are not façade. This paper presents an automatic approach to façade region detection given a single street view image as a pre-processing step to subsequent steps of façade identification. We devise a coarse façade region detection method based on the observation that façades are image regions with repetitive patterns containing a large amount of vertical and horizontal line segments. Firstly, scan lines are constructed from vanishing points and center points of image line segments. Hue profiles along these lines are then analyzed and used to decompose the image into rectilinear patches with similar repetitive patterns. Finally, patches are merged into larger coherent regions and the main building façade region is chosen based on the occurrence of horizontal and vertical line segments within each of the merged regions. A validation of our method showed that on average façade regions are detected in conformity with manually segmented images as ground truth.

  • 38.
    Liu, Fei
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Detection of Line Features in Digital Images of Building Structures2012In: Proceedings of IADIS International Conference Computer Graphics, Visualization, Computer Vision and Image Processing 2012 (CGVCVIP 2012) / [ed] Yingcai Xiao, 2012, p. 163-167Conference paper (Refereed)
    Abstract [en]

    This paper describes method for detection of short line segments in digital images. It aims at identifying buildingsin images taken from the ground view. The process starts with the image edge map and is carried out in twodifferent levels. One is to detect long line segments usually stemming from façade edges and building silhouettes.The other one identifies shorter line segments which typically represent architectural details such as windows andentrances. Selected individual connected components in both vertical and horizontal gradient component mapsare used respectively as input to the Hough transform at this level. Our first result shows that this method iscapable of recognizing lines of interest but has also included many randomly oriented lines. The next step will beto eliminate the random line segments and correlate line segments of the two levels to classify high-level features ofbuildings in an image.

  • 39.
    Liu, Fei
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science. Centre for Image Analysis, Uppsala University, Uppsala, Sweden.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science. Centre for Image Analysis, Uppsala University, Uppsala, Sweden.
    Infrared-visible image registration for augmented reality-based thermographic building diagnostics2015In: Visualization in Engineering, ISSN 2213-7459, Vol. 3, no 1, article id 16Article in journal (Refereed)
    Abstract [en]

    Background: In virtue of their capability to measure temperature, thermal infrared cameras have been widely used in building diagnostics for detecting heat loss, air leakage, water damage etc. However, the lack of visual details in thermal infrared images makes the complement of visible images a necessity. Therefore, it is often useful to register images of these two modalities for further inspection of architectures. Augmented reality (AR) technology, which supplements the real world with virtual objects, offers an ideal tool for presenting the combined results of thermal infrared and visible images. This paper addresses the problem of registering thermal infrared and visible façade images, which is essential towards developing an AR-based building diagnostics application. Methods: A novel quadrilateral feature is devised for this task, which models the shapes of commonly present façade elements, such as windows. The features result from grouping edge line segments with the help of image perspective information, namely, vanishing points. Our method adopts a forward selection algorithm to determine feature correspondences needed for estimating the transformation model. During the formation of the feature correspondence set, the correctness of selected feature correspondences at each step is verified by the quality of the resulting registration, which is based on the ratio of areas between the transformed features and the reference features. Results and conclusions: Quantitative evaluation of our method shows that registration errors are lower than errors reported in similar studies and registration performance is usable for most tasks in thermographic inspection of building façades.

  • 40.
    Liu, Fei
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science. Centre for Image Analysis, Uppsala University, Uppsala, Sweden.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science. Centre for Image Analysis, Uppsala University.
    On the precision of third person perspective augmented reality for target designation tasks2017In: Multimedia tools and applications, ISSN 1380-7501, E-ISSN 1573-7721, Vol. 76, no 14, p. 15279-15296Article in journal (Refereed)
    Abstract [en]

    The availability of powerful consumer-level smart devices and off-the-shelf software frameworks has tremendously popularized augmented reality (AR) applications. However, since the built-in cameras typically have rather limited field of view, it is usually preferable to position AR tools built upon these devices at a distance when large objects need to be tracked for augmentation. This arrangement makes it difficult or even impossible to physically interact with the augmented object. One solution is to adopt third person perspective (TPP) with which the smart device shows in real time the object to be interacted with, the AR information and the user herself, all captured by a remote camera. Through mental transformation between the user-centric coordinate space and the coordinate system of the remote camera, the user can directly interact with objects in the real world. To evaluate user performance under this cognitively demanding situation, we developed such an experimental TPP AR system and conducted experiments which required subjects to make markings on a whiteboard according to virtual marks displayed by the AR system. The same markings were also made manually with a ruler. We measured the precision of the markings as well as the time to accomplish the task. Our results show that although the AR approach was on average around half a centimeter less precise than the manual measurement, it was approximately three times as fast as the manual counterpart. Additionally, we also found that subjects could quickly adapt to the mental transformation between the two coordinate systems.

  • 41.
    Liu, Fei
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science. Centre for Image Analysis, Uppsala University, Uppsala, Sweden.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science. Centre for Image Analysis, Uppsala University, Uppsala, Sweden.
    Precision study on augmented reality-based visual guidance for facility management tasks2018In: Automation in Construction, ISSN 0926-5805, E-ISSN 1872-7891, Vol. 90, p. 79-90Article in journal (Refereed)
    Abstract [en]

    One unique capability of augmented reality (AR) is to visualize hidden objects as a virtual overlay on real occluding objects. This “X-ray vision” visualization metaphor has proved to be invaluable for operation and maintenance tasks such as locating utilities behind a wall. Locating virtual occluded objects requires users to estimate the closest projected positions of the virtual objects upon their real occluders, which is generally under the influence of a parallax effect. In this paper we studied the task of locating virtual pipes behind a real wall with “X-ray vision” and the goal is to establish relationships between task performance and spatial factors causing parallax through different forms of visual augmentation. We introduced and validated a laser-based target designation method which is generally useful for AR-based interaction with augmented objects beyond arm's reach. The main findings include that people can mentally compensate for the parallax error when extrapolating positions of virtual objects on the real surface given traditional 3D depth cues for spatial understanding. This capability is, however, unreliable especially in the presence of the increasing viewing offset between the users and the virtual objects as well as the increasing distance between the virtual objects and their occluders. Experiment results also show that positioning performance is greatly increased and unaffected by those factors if the AR support provides visual guides indicating the closest projected positions of virtual objects on the surfaces of their real occluders.

  • 42.
    Ma, Lei
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Brandt, S. Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science. Division of Visual Information and Interaction, Department of Information Technology, Uppsala University, Uppsala, Sweden.
    Ma, Ding
    Research Institute for Smart Cities, School of Architecture and Urban Planning, Shenzhen University, Shenzhen, China.
    Simple agents – complex emergent path systems: Agent-based modelling of pedestrian movement2023In: Environment and Planning B: Urban Analytics and City Science, ISSN 2399-8083Article in journal (Refereed)
    Abstract [en]

    In well-planned open and semi-open urban areas, it is common to observe desire paths on the ground, which shows how pedestrians themselves enhance the walkability and affordance of road systems. To better understand how these paths are formed, we present an agent-based modelling approach that simulates real pedestrian movement to generate complex path systems. By using heterogeneous ground affordance and visit frequency of hotspots as environmental settings and by modelling pedestrians as agents, path systems emerge from collective interactions between agents and their environment. Our model employs two visual parameters, angle and depth of vision, and two guiding principles, global conception and local adaptation. To examine the model’s visual parameters and their effects on the cost-efficiency of the emergent path systems, we conducted a randomly generated simulation and validated the model using desire paths observed in real scenarios. The results show that (1) the angle (found to be limited to a narrow range of 90–120°) has a more significant impact on path patterns than the depth of vision, which aligns with Space Syntaxtheories that also emphasize the importance of angle for modelling pedestrian movement; (2) the depth of vision is closely related to the scale-invariance of path patterns on different map scales; and(3) the angle has a negative exponential correlation with path efficiency and a positive correlation with path costs. Our proposed model can help urban planners predict or generate cost-efficient path installations in well- and poorly designed urban areas and may inspire further approaches rooted in generative science for future cities.

    Download full text (pdf)
    fulltext
  • 43.
    Ma, Lei
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science. Uppsala universitet.
    Brandt, S. Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Ma, Ding
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences. Shenzhen University, China.
    A New Graph-Based Fractality Index to Characterize Complexity of Urban Form2022In: ISPRS International Journal of Geo-Information, ISSN 2220-9964, Vol. 11, no 5, article id 287Article in journal (Refereed)
    Abstract [en]

    Examining the complexity of urban form may help to understand human behavior in urban spaces, thereby improving the conditions for sustainable design of future cities. Metrics, such as fractal dimension, ht-index, and cumulative rate of growth (CRG) index have been proposed to measure this complexity. However, as these indicators are statistical rather than spatial, they result in an inability to characterize the spatial complexity of urban forms, such as building footprints. To overcome this problem, this paper proposes a graph-based fractality index (GFI), which is based on a hybrid of fractal theory and deep learning techniques. First, to quantify the spatial complexity, several fractal variants were synthesized to train a deep graph convolutional neural network. Next, building footprints in London were used to test the method, where the results showed that the proposed framework performed better than the traditional indices, i.e., the index is capable of differentiating complex patterns. Another advantage is that it seems to assure that the trained deep learning is objective and not affected by potential biases in empirically selected training datasets Furthermore, the possibility to connect fractal theory and deep learning techniques on complexity issues opens up new possibilities for data-driven GIS science.

    Download full text (pdf)
    fulltext
  • 44.
    Milutinovic, Goran
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Ahonen-Jonnarth, Ulla
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Decision, Risk and Policy Analysis.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science. Uppsala universitet.
    Does visual saliency affect decision-making?2021In: Journal of Visualization, ISSN 1343-8875, E-ISSN 1875-8975, Vol. 24, p. 1267-1285Article in journal (Refereed)
    Abstract [en]

    In the present study, we explore potential effects of visual saliency on decision quality in context of multi-criteria decision-making (MCDM). We compare two visualization techniques: parallel coordinates (PC) and scatterplot matrices (SPM). We investigate the impact of saliency facilitated by means of either color or size. The saliency and visualization techniques were factors in our analysis, and effects were evaluated in terms of decision quality, attention, time on task, and confidence. Results show that the quality of choice and attention were comparable for all saliency conditions when SPM was used. For PC, we found a positive effect of color saliency both on the quality of choice and on attention. Different forms of saliency led to varying times on task in both PC and SPM; however, those variations were not significant. A comparison of PC and SPM shows, users spent less time on the task, obtained better decision quality, and were more confident with their decision when using PC. To summarize, our findings suggest that saliency can increase attention and decision quality in MCDM for certain visualization techniques and forms of saliency. Another contribution of this work is the novel suggestion of the method to elicit of users’ preferences; its potential benefits are discussed in the end of the paper.

    Download full text (pdf)
    fulltext
  • 45.
    Milutinovic, Goran
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Ahonen-Jonnarth, Ulla
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Decision, Risk and Policy Analysis.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science. Department of Information Technology, Uppsala University, Uppsala, Sweden.
    GISwaps: A New Method for Decision Making in Continuous Choice Models Based on Even Swaps2018In: International Journal of Decision Support System Technology, ISSN 1941-6296, E-ISSN 1941-630X, Vol. 10, no 3, p. 57-78Article in journal (Refereed)
    Abstract [en]

    This article describes how continuous GIS-MCDM problems are commonly managed by combining some weighting method based on pairwise comparisons of criteria with an aggregation method. The reliability of this approach may be questioned, though. First, assigning weights to criteria, without taking into consideration the actual consequences or values of the alternatives, is in itself controversial. Second, the value functions obtained by this approach are in most cases linear, which is seldom the case in reality. The authors present a new method for GIS-MCDM in continuous choice models based on Even Swaps. The method is intuitive and easy to use, based on value trade-offs, and thus not relying on criteria weighting. Value functions obtained when using the method may be linear or non-linear, and thereby are more sensitive to the characteristics of the decision space. The performed case study showed promising results regarding the reliability of the method in GIS-MCDM context.

    Download full text (pdf)
    fulltext
  • 46.
    Milutinovic, Goran
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Ahonen-Jonnarth, Ulla
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Decision, Risk and Policy Analysis.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science. Division of Visual Information and Interaction, Department of Information Technology, Uppsala University, Uppsala, Sweden.
    Brandt, S. Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    The impact of interactive visualization on trade-off-based geospatial decision-making2019In: International Journal of Geographical Information Science, ISSN 1365-8816, E-ISSN 1365-8824, Vol. 33, no 10, p. 2094-2123Article in journal (Refereed)
    Abstract [en]

    In a previous work we developed GISwaps, a novel method for geospatial decision-making based on Even Swaps. In this paper, we present the results of an evaluation of a visualization framework integrated with this method, implemented within a decision support system. This evaluation is based on two different studies. In the quantitative study, 15 student participants used GISwaps with no visual features, and 15 participants used GISwaps with the integrated visual framework, as the tool in a solar farm site location case study. The results of the quantitative evaluation show positive impact of the visualization in terms of increased coherency in trade-offs. The results also show a statistically significant difference in average trade-off values between the groups, with users from the non-visual group setting on average 20% higher trade-off values compared with the users in the visual group. In the qualitative study, we had one expert in GIS, two experts in decision-making and two experts in solar energy as a focus user group. Data in this study were obtained by observations and semi-structured interviews with the participants. The impact of the visualization framework was assessed positively by all participants in the expert group. 

    Download full text (pdf)
    fulltext
  • 47.
    Milutinovic, Goran
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Visual GISwaps - an interactive visualization framework for geospatial decision making2018In: Proceedings of the 13th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications, VISIGRAPP 2018, Funchal, Madeira - Portugal, January 27-29, 2018 / [ed] Alexandru Telea, Andreas Kerren and Jose Braz, SciTePress, 2018, p. 236-243Conference paper (Refereed)
    Abstract [en]

    Different visualization techniques are frequently used in geospatial information systems (GIS) to support geospatial decision making. However, visualization in GIS context is usually limited to the initial phase of the decision-making process, i.e. situation analysis and problem recognition. This is partly due to the choice of methods used in GIS multi-criteria decision-making (GIS-MCDM) that usually deploy some non-interactive approach, leaving the decision maker little or no control over the calculation of overall values for the considered alternatives; the role of visualization is thus reduced to presenting the final results of the computations. The contributions of this paper are twofold. First, we introduce GISwaps, a novel, intuitive interactive method for decision making in geospatial context. The second and main contribution is an interactive visualization of the choice phase of the decision making process. The visualization allows the decision maker to explore the consequences of trade-offs and costs accepted during the iterative decision process, both in terms of the abstract relation between different decision variables and in spatial context.

  • 48.
    Milutinovic, Goran
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science. Uppsala universitet.
    Ahonen-Jonnarth, Ulla
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Decision, Risk and Policy Analysis.
    Geospatial decision-making framework based on the concept of satisficing2021In: ISPRS International Journal of Geo-Information, ISSN 2220-9964, Vol. 10, no 5, article id 326Article in journal (Refereed)
    Abstract [en]

    Decision-making methods used in geospatial decision-making are often computationally complex prescriptive methods, details of which are rarely transparent to the decision maker. However, having a deep understanding of the details and mechanisms of the applied method is a prerequisite for the efficient use thereof. In this paper, we present a novel decision-making framework that emanates from the need for intuitive and easy-to-use decision support systems for geospatial multi-criteria decision-making. The framework consists of two parts: the decision making model, and the interactive visualization framework. The decision-making model is based on the concept of quasi-satisficing, and as such, it is intuitive and easy to understand and apply. It integrates even swaps, a prescriptive decision-making method, with the findings of behavioural decision-making theories. Providing visual feedback and interaction opportunities throughout the decision-making process, the interactive visualization part of the framework helps the decision maker gain better insight into the decision space and attribute dependencies. Furthermore, it provides the means to analyse and compare the outcomes of different scenarios and decision paths.

    Download full text (pdf)
    fulltext
  • 49. Nyström, Ingela
    et al.
    Olsson, Pontus
    Nysjö, Johan
    Nysjö, Fredrik
    Malmberg, Filip
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Hirsch, Jan-Michel
    Carlbom, Ingrid B.
    Virtual Cranio-Maxillofacial Surgery Planning with Stereo Graphics and Haptics2016In: Computer-Assisted Musculoskeletal Surgery: Thinking and Executing in 3D / [ed] Ritacco, L .E. and Milano, F. E. and Chao, E., Springer Publishing Company, 2016, 1, p. 29-42Chapter in book (Refereed)
  • 50.
    Ohlsson, P
    et al.
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Seipel, Stefan
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Real-time Rendering of Accumulated Snow2004In: Proceedings of the Annual SIGRAD Conference, 2004, p. 25-32Conference paper (Other academic)
123 1 - 50 of 104
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard-cite-them-right
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • sv-SE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • de-DE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf