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  • 1.
    Abshirini, Ehsan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Koch, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Rivers as integration devices in cities2016In: City, Territory and Architecture, ISSN 0885-7024, E-ISSN 2195-2701, Vol. 3, no 1, p. 1-21Article in journal (Refereed)
    Abstract [en]

    Background: As dynamic systems rivers and cities have been in interaction under changing relations over time, and the morphology of many cities has risen through a long and steady struggle between the city functions and the river system flowing inside. This makes river cities an interesting case to study how the presence of geographical features interacts with spatial morphology in the formation of cities.

    Methods: The basis of this research is enabled by utilizing a novel model for cross-city comparison presented by Hillier in his Santiago keynote in 2012 called a “star model”. This is done on large samples of cities investigating concurrent configurations, as well as how the properties in this star model react to specific forms of disturbance.

    Results: Results illustrate that the foreground network as identified through maximum choice values in cities are more vital to the structure of cities than the bridges. The overall syntactic structure tends to retain its character (degree of distributedness) and the location of its foreground network (which street segments constitute the foreground network) even when bridges are targeted. Furthermore, counter to the initial hypothesis, river cities tend to change less than non-river cities after targeted disturbance of the systems. Finally, the results show that while there is a statistical morphological difference between river cities and non-river cities, this difference is not directly explained through the bridges.

    Conclusion: Integrating space syntax with statistical and geospatial analysis can throw light on the way in which the properties of city networks and urban structure reflect the relative effect of rivers on the morphology of river cities. The paper, finally, contributes through offering one piece of a better perception of the structure of river-cities that can support strategies of river-cities interaction as well as enhance our knowledge on the constraints and limits to that interaction.

  • 2.
    Abshirini, Ehsan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Koch, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Legeby, Ann
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Flood hazard and its impact on the resilience of cities: An accessibility-based approach to amenities in the city of Gothenburg, Sweden2017In: Proceedings - 11th International Space Syntax Symposium, SSS 2017, Instituto Superior Tecnico, Departamento de Engenharia Civil, Arquitetura e Georrecursos , 2017, p. 36.1-36.15Conference paper (Refereed)
    Abstract [en]

    In the wake of climate change and its impact on increasing the number and intensity of floods, adaptability of cities to and resistance against the flood hazard is critical to retain functionality of the cities. Vulnerability of urban infrastructure and its resilience to flooding from different points of view have been important and worth investigating for experts in different fields of science. Flood hazards as physical phenomena are influenced by form of the cities and thus the magnitude of their impacts can be intensified by urban infrastructures such as street networks and buildings (Bacchin et. al, 2011). In this paper, we aim to develop a method to assess the resilience of a river city (the city of Gothenburg in Sweden), which is prone to flood events, against such disturbances and find out how the city reacts to river floods and to what extent the city retains its accessibility to essential amenities after a flood occurs. To do so, collecting required data; we, firstly, simulate flood inundation with two different return periods (50 and 1000 years) and then the impact areas overlay on the street networks. Evaluating the resilience of the city, syntactic properties of the street networks before and after flooding are measured at different scales. Additionally, accessibility and the minimum distance of the street networks to essential amenities such as healthcare centers, schools and commercial centers, at a medium distance (3 Km) is examined. The results show that flooding influences the city configuration at global scale more than the local scale based on comparison of syntactic properties before and after flooding. However, the results of accessibility and the minimum distance show that the impact of flooding on the functionality of the city is more limited to the riparian areas and the city is not affected globally.

  • 3.
    Abshirini, Ehsan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Koch, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Architecture, Urban Design.
    Legeby, Ann
    KTH, School of Architecture and the Built Environment (ABE), Architecture, Urban Design.
    Flood Resilient Cities: A Syntactic and Metric Novel on Measuring the Resilience of Cities against Flooding, Gothenburg, Sweden2017In: Journal of Geographic Information System, ISSN 2151-1950, E-ISSN 2151-1969, Vol. 9, p. 505-534Article in journal (Refereed)
    Abstract [en]

    Flooding is one of the most destructive natural disasters which have rapidly been growing in frequency and intensity all over the world. In this view, assessment of the resilience of the city against such disturbances is of high necessity in order to significantly mitigate the disaster effects of flooding on the city structures and the human lives. The aim of this paper is to develop a method to assess the resilience of a river city (the city of Gothenburg in Sweden), which is prone to flood Hazard, against such disturbances. By simulating flood inundation with different return periods, in the first step, the areas of impact are determined. To assess the resilience, two different methods are followed. One is a syntactic method grounded in the foreground network in space syntax theory and the other is based on measuring accessibility to the essential amenities in the city. In the first method, similarity and sameness parameters are defined to quantitatively measure the syntactic resilience in the city. In the next step, accessibility to amenities and the minimum distance to amenities before and after each disturbance is measured. The results, in general, show that such disturbances affect the city structure and the resilience of the city differently. For instance, the city is more resilient after flooding ac- cording to accessibility measures. This clearly means that the answer to the question of resilience is mainly dependent on “resilience of what and for what.”

  • 4.
    Adjei-Darko, Priscilla
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Remote Sensing and Geographic Information Systems for Flood Risk Mapping and Near Real-time Flooding Extent Assessment in the Greater Accra Metropolitan Area2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Disasters, whether natural or man-made have become an issue of mounting concern all over the world. Natural disasters such as floods, earthquakes, landslides, cyclones, tsunamis and volcanic eruptions are yearly phenomena that have devastating effect on infrastructure and property and in most cases, results in the loss of human life. Floods are amongst the most prevalent natural disasters. The frequency with which floods occur, their magnitude, extent and the cost of damage are escalating all around the globe. Accra, the capital city of Ghana experiences the occurrence of flooding events annually with dire consequences. Past studies demonstrated that remote sensing and geographic information system (GIS) are very useful and effective tools in flood risk assessment and management.  This thesis research seeks to demarcate flood risk areas and create a flood risk map for the Greater Accra Metropolitan Area using remote sensing and Geographic information system. Multi Criteria Analysis (MCA) is used to carry out the flood risk assessment and Sentinel-1A SAR images are used to map flood extend and to ascertain whether the resulting map from the MCA process is a close representation of the flood prone areas in the study area.  The results show that the multi-criteria analysis approach could effectively combine several criteria including elevation, slope, rainfall, drainage, land cover and soil geology to produce a flood risk map. The resulting map indicates that over 50 percent of the study area is likely to experience a high level of flood.  For SAR-based flood extent mapping, the results show that SAR data acquired immediately after the flooding event could better map flooding extent than the SAR data acquired 9 days after.  This highlights the importance of near real-time acquisition of SAR data for mapping flooding extent and damages.  All parts under the study area experience some level of flooding. The urban land cover experiences very high, and high levels of flooding and the MCA process produces a risk map that is a close depiction of flooding in the study area.  Real time flood disaster monitoring, early warning and rapid damage appraisal have greatly improved due to ameliorations in the remote sensing technology and the Geographic Information Systems.

  • 5.
    Althén Bergman, Felix
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Improving the location of existing recycling stations using GIS2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 6.
    Alvarez, Manuela
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Mapping forest habitats in protected areas by integrating LiDAR and SPOT Multispectral Data2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    KNAS (Continuous Habitat Mapping of Protected Areas) is a Metria AB project that produces vegetation and habitat mapping in protected areas in Sweden. Vegetation and habitat mapping is challenging due to its heterogeneity, spatial variability and complex vertical and horizontal structure. Traditionally, multispectral data is used due to its ability to give information about horizontal structure of vegetation. LiDAR data contains information about vertical structure of vegetation, and therefore contributes to improve classification accuracy when used together with spectral data. The objectives of this study are to integrate LiDAR and multispectral data for KNAS and to determine the contribution of LiDAR data to the classification accuracy. To achieve these goals, two object-based classification schemes are proposed and compared: a spectral classification scheme and a spectral-LiDAR classification scheme. Spectral data consists of four SPOT-5 bands acquired in 2005 and 2006. Spectral-LiDAR includes the same four spectral bands from SPOT-5 and nine LiDAR-derived layers produced from NH point cloud data from airborne laser scanning acquired in 2011 and 2012 from The Swedish Mapping, Cadastral and Land Registration Authority. Processing of point cloud data includes: filtering, buffer and tiles creation, height normalization and rasterization. Due to the complexity of KNAS production, classification schemes are based on a simplified KNAS workflow and a selection of KNAS forest classes. Classification schemes include: segmentation, database creation, training and validation areas collection, SVM classification and accuracy assessment. Spectral-LiDAR data fusion is performed during segmentation in eCognition. Results from segmentation are used to build a database with segmented objects, and mean values of spectral or spectral-LiDAR data. Databases are used in Matlab to perform SVM classification with cross validation. Cross validation accuracy, overall accuracy, kappa coefficient, producer’s and user’s accuracy are computed. Training and validation areas are common to both classification schemes. Results show an improvement in overall classification accuracy for spectral-LiDAR classification scheme, compared to spectral classification scheme. Improvements of 21.9 %, 11.0 % and 21.1 % are obtained for the study areas of Linköping, Örnsköldsvik and Vilhelmina respectively. 

  • 7.
    Azaronak, Natallia
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Building 3D models from geotechnical data2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Building Information Modelling (BIM) and Virtual Reality (VR) are two of the main directions in the BIM-strategy of the Swedish Transport Administration. Starting from the year 2015 it is a requirement to use BIM even in tenders.

    In order to meet these requirements WSP developed their own product Open VR - a data platform for visualization, communication, planning, designing as well as a tool for documentation of new and existing environments.

    Geotechnical analysis is an important part in most of the projects and affects the economy, the projects timeframes and further projects design greatly. Availability of good quality basic data is a requirement to succeed in a project.  Inaccurate and late delivered rock and soil 3D models cause the problems at the design stage. A completely or partially automated process for creating 3D soil models using geotechnical database and models presentation in Open VR would provide both economic benefits and reduce the amount of repetitive work in the CAD environment.

    One of the biggest issues is to combine data coming from different sources and therefore clear standards on how different fields of technology should prepare their information are needed. The goal of this master thesis is to develop a guideline how to prepare geotechnical objects for Open-VR.

    Firstly software that could be used for preparing geotechnical data for Open VR were identified and described. Three products were chosen: NovaPoint, Civil3D, Power Civil. After that data were processed using the software chosen for comparison. Geotechnical objects (3D models of soil layers and 3D boreholes) were prepared for Open VR using these three products. The results were evaluated. Finally a guideline for preparing geotechnical data for Open VR was written. This guideline can be used not only for preparing the geotechnical data for Open VR but for any other product which can be used for the model coordination (for example, NavisWorks etc). This guideline can be used in any geotechnical project where geotechnical data of Swedish standard are used. This guideline can be used as it is in order to create 3D models of soil layers and rock surfaces with help of Civil3D. In case that another kind of software should be used, this guideline can be used as a basis, because the workflow is the same, but some correction can be done concerning what “button should be pressed”.

    Recommendations were given depending on the project requirements and application area. Taking into account that WSP decided to not continue with NovaPoint and use Civil 3D and Power Civil instead, then it is recommended to use Civil 3D when it is necessary to create soil layers using field investigations. Results of 3D modelling can be used in NovaPoint, loaded to Open VR and, if necessary, even be imported into Power Civil.

    Power Civil can be used in large-scale projects where advanced 3D modelling is required or when all other area of technology use Power Civil for project design.

    Even though NovaPoint does not have priority at WSP it should not be out of the game, it can be very useful in projects where the usage of BIM is a requirement. Considering that NovaPoint has good communication with GeoSuite and can produce smart 3D models it is recommended to have a license of NovaPoint at WSP in order being able to follow software development.

  • 8.
    Azcarate, Juan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Mörtberg, Ulla
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Haas, Jan
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Balfors, Berit
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Reaching compact green cities: A study of the provision of and pressure on cultural ecosystem services in StockholmManuscript (preprint) (Other academic)
  • 9.
    Ban, Yifang
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Multitemporal ERS-1 SAR and Landsat TM data for agricultural crop classification: comparison and synergy2003In: Canadian journal of remote sensing, ISSN 0703-8992, E-ISSN 1712-7971, Vol. 29, no 4, p. 518-526Article in journal (Refereed)
    Abstract [en]

    The objective of this research was to evaluate the synergistic effects of multitemporal European remote sensing satellite 1 (ERS-1) synthetic aperture radar (SAR) and Landsat thematic mapper (TM) data for crop classification using a per-field artificial neural network (ANN) approach. Eight crop types and conditions were identified: winter wheat, corn (good growth), corn (poor growth), soybeans (good growth), soybeans (poor growth), barley/oats, alfalfa, and pasture. With the per-field approach using a feed-forward ANN, the overall classification accuracy of three-date early- to mid-season SAR data improved almost 20%, and the best classification of a single-date (5 August) SAR image improved the overall accuracy by about 26%, in comparison to a per-pixel maximum-likelihood classifier (MLC). Both single-date and multitemporal SAR data demonstrated their abilities to discriminate certain crops in the early and mid-season; however, these overall classification accuracies (<60%) were not sufficiently high for operational crop inventory and analysis, as the single-parameter, high-incidence-angle ERS-1 SAR system does not provide sufficient differences for eight crop types and conditions. The synergy of TM3, TM4, and TM5 images acquired on 6 August and SAR data acquired on 5 August yielded the best per-field ANN classification of 96.8% (kappa coefficient = 0.96). It represents an 8.3% improvement over TM3, TM4, and TM5 classification alone and a 5% improvement over the per-pixel classification of TM and 5 August SAR data. These results clearly demonstrated that the synergy of TM and SAR data is superior to that of a single sensor and the ANN is more robust than MLC for per-field classification. The second-best classification accuracy of 95.9% was achieved using the combination of TM3, TM4, TM5, and 24 July SAR data. The combination of TM3, TM4, and TM5 images and three-date SAR data, however, only yielded an overall classification accuracy of 93.89% (kappa = 0.93), and the combination of TM3, TM4, TM5, and 15 June SAR data decreased the classification accuracy slightly (88.08%; kappa = 0.86) from that of TM alone. These results indicate that the synergy of satellite SAR and Landsat TM data can produce much better classification accuracy than that of Landsat TM alone only when careful consideration is given to the temporal compatibility of SAR and visible and infrared data.

  • 10.
    Ban, Yifang
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Multitemporal remote sensing: Current status, trends and challenges2016In: Remote Sensing and Digital Image Processing, 2016, p. 1-18Conference paper (Refereed)
    Abstract [en]

    Our planet is facing unprecedented environmental challenges including rapid urbanization, deforestation, pollution, loss of biodiversity, sea-level rising, melting polar ice-caps and climate change. With its synoptic view and the repeatability, remote sensing offers a powerful and effective means to observe and monitor our changing planet at local, regional and global scale. Since the launch of Landsat-1 in 1972, numerous Earth Observation satellites have been launched providing large volumes of multitemporal data acquired by multispectral, hyperspectral, passive microwave, synthetic aperture radar (SAR), and LiDAR sensors. This chapter first presents an overview of the Earth Observation sensors and trends in multitemporal observation capacity. Then the current status, challenges and opportunities of multitemporal remote sensing are discussed. Finally the synopsis of the book is provided covering a wide array of methods and techniques in processing and analysis of multitemporal remotely sensed images as well as a variety of application examples in both land and aquatic environments.

  • 11.
    Ban, Yifang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Gamba, P.
    EO4Urban: First-year results on Sentinel-1A SAR and Sentinel-2A MSI data for global urban services2016In: European Space Agency, (Special Publication) ESA SP, 2016Conference paper (Refereed)
    Abstract [en]

    The overall objective of this research is to evaluate multitemporal Sentinel-1A SAR and Sentinel-2A MSI data for global urban services using innovative methods and algorithms, namely KTH-Pavia Urban Extractor, a robust algorithm for urban extent extraction and KTHSEG, a novel object-based classification method for detailed urban land cover mapping. Ten cities around the world in different geographical and environmental conditions were selected as study areas. Large volume of Sentinel-1A SAR and Sentinel-2A MSI data were acquired during vegetation season in 2015 and 2016. The preliminary urban extraction results showed that urban areas and small towns could be well extracted using multitemporal Sentinel-1A SAR data with the KTH-Pavia Urban Extractor. For urban land cover mapping, multitemporal Sentinel-1A SAR data alone yielded an overall classification accuracy of 60% for Stockholm. Sentinel-2A MSI data as well as the fusion of Sentinel-1A SAR and Sentinel-2A MSI data, however, produced much higher classification accuracies, both reached 80%.

  • 12.
    Ban, Yifang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Gamba, Paolo
    Gong, Peng
    Du, Peijun
    Satellite Monitoring of Urbanization in China for Sustainable Development: The Dragon 'Urbanization' Project2011In: IEEE EarthzineArticle in journal (Other (popular science, discussion, etc.))
  • 13.
    Ban, Yifang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Gamba, Paolo
    Jacob, Alexander
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Salentining, A.
    Multitemporal, multi-rsolution SAR data for urbanization mapping and monitoring: midterm results2014In: Proceedings of the Dragon 3 mid-term results Symposium, ESA , 2014Conference paper (Other academic)
  • 14.
    Ban, Yifang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Gong, P.
    Gamba, P.
    Du, P.
    Satellite monitoring of urbanization in China for sustainable development: Final results2013In: European Space Agency, (Special Publication) ESA SP, Volume 704 SP, 2013, European Space Agency, 2013Conference paper (Refereed)
    Abstract [en]

    The overall objectives of this research are to investigate spaceborne SAR data, optical data and fusion of SAR and optical data for urbanization monitoring in China, and to assess the impact of urbanization on the environment for sustainable development. Effective segmentation and classification methods for urban extent extraction and land cover mapping were developed. Several change detection algorithms and approaches using SAR and optical data were evaluated. Further, synergistic effects of multisensor SAR data as well as ASAR and HJ-1B data are examined. The results show that the developed methods were effective for urban extent extraction, land cover mapping and change detection. The fusion of multisensor spaceborne SAR as well as fusion of ASAR and HJ-1 data were beneficial for urban land cover mapping. The spatiotemporal patterns of urbanization in China were analyzed. The results show that rapid urbanization in Yangtze River Delta, Jingjinji and Pearl River Delta has a significant impact on the environment in terms of landscape fragmentation and ecosystem services.

  • 15.
    Ban, Yifang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Howarth, P. J.
    Multitemporal ERS-1 SAR data for crop classification: a sequential-masking approach1999In: Canadian journal of remote sensing, ISSN 0703-8992, E-ISSN 1712-7971, Vol. 1999, no 25, p. 438-447, article id 5Article in journal (Refereed)
    Abstract [en]

    Based on photo-interpretation procedures, the technique of sequential masking can be used to differentiate image features using a series of multitemporal images. In this study, a set of nine ERS-1 SAR images is analyzed using this technique to determine the earliest dates for identifying different crop types in an agricultural area of southern Ontario, Canada. SAR temporal backscatter profiles of crops were generated from calibrated radar imagery. Based on these temporal backscatter profiles, per-field classifications using the sequential-masking technique were performed on the early- and mid-season multitemporal SAR data. It was found that using only three images, acquired on May 31, June 16 and July 5, it is possible to differentiate winter wheat, alfalfa/hay, barley/oats, soybeans and corn with an overall validation accuracy of 88.5% and a Kappa coefficient of 0.85.

  • 16.
    Ban, Yifang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Howarth, P. J.
    Orbital effects on ERS-1 SAR temporal backscatter profiles of agricultural crops1997In: ESA SP, 1997, p. 179-183Conference paper (Other academic)
  • 17.
    Ban, Yifang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Howarth, P. J.
    Orbital effects on ERS-1 SAR temporal backscatter profiles of agricultural crops1998In: International Journal of Remote Sensing, ISSN 0143-1161, E-ISSN 1366-5901, Vol. 19, no 17, p. 3465-3470Article in journal (Refereed)
    Abstract [en]

    Multi-temporal radar backscatter characteristics of crops and their underlying soils were analysed for an agricultural area in south-western Ontario, Canada using nine dates of ERS-1 SAR imagery acquired during the 1993 growing season. From the calibrated data, SAR temporal backscatter profiles were generated for each crop type. The results indicate that small changes in incidence-angle can have strong impacts on radar backscatter. Thus, attention must be given to local incidence-angle effects when using ERS-1 SAR data,especially when comparing backscatter coefficients of the same area from different scenes or different areas within the same scene.

  • 18.
    Ban, Yifang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Jacob, Alexander
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Geoinformatics. KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Fusion of multitemporal spaceborne SAR and optical data for urban mapping and urbanization monitoring2016In: Remote Sensing and Digital Image Processing, ISSN 1567-3200, p. 107-123Article in journal (Refereed)
    Abstract [en]

    The overall objective of this research is to evaluate multitemporal spaceborne SAR and optical data for urban land cover mapping and urbanization monitoring. Multitemporal Sentinel-1A SAR and historical ERS SAR and ENVISAT ASAR data as well as HJ-1B multispectral data were acquired in Beijing, Chendgdu and Nanchang, China where rapid urbanization has taken place. KTHSEG, a novel object-based classification method is adopted for urban land cover mapping while KTH-Pavia Urban Extractor, a robust algorithm is improved for urban extent extraction and urbanization monitoring. The research demonstrates that, for urban land cover classification, the fusion of multitemporal SAR and optical data is superior to SAR or optical data alone. The second best classification result is achieved using fusion of 4-date SAR and one HJ-1B image. The results indicate that carefully selected multitemporal SAR dataset and its fusion with optical data could produce nearly as good classification accuracy as the whole multitemporal dataset. The results also show that KTH-SEG, the edge-aware region growing and merging segmentation algorithm, is effective for classification of SAR, optical and their fusion. KTH-SEG outperforms eCognition, the commonly used commercial software, for image segmentation and classification of linear features. For Urban extent extraction, single-date and multitemporal SAR data including ERS SAR, ENVISAT ASAR and Sentinel-1A SAR achieved very promising results in all study areas using the improved KTH-Pavia Urban Extractor. The results showed that urban areas as well as small towns and villages could be well extracted using multitemporal Sentinel-1A SAR data while major urban areas could be well extracted using a single-date single-polarization SAR image. The results clearly demonstrate that multitemporal SAR data are cost- and time-effective way for monitoring spatiotemporal patterns of urbanization. © Springer International Publishing AG 2016.

  • 19.
    Ban, Yifang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Marullo, Salvatore
    Eklundh, Lars
    European Remote Sensing: progress, challenges, and opportunities2017In: International Journal of Remote Sensing, ISSN 0143-1161, E-ISSN 1366-5901, Vol. 38, no 7, p. 1759-1764Article in journal (Refereed)
  • 20.
    Ban, Yifang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Webber, Luke
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Gamba, P.
    Paganini, M.
    EO4Urban: Sentinel-1A SAR and Sentinel-2A MSI data for global urban services2017In: 2017 Joint Urban Remote Sensing Event, JURSE 2017, Institute of Electrical and Electronics Engineers (IEEE), 2017, article id 7924550Conference paper (Refereed)
    Abstract [en]

    The overall objective of this research is to evaluate multitemporal Sentinel-1A SAR and Sentinel-2A MSI data for global urban services using innovative methods and algorithms, namely KTH-Pavia Urban Extractor, a robust algorithm for urban extent extraction and KTH-SEG, a novel object-based classification method for detailed urban land cover mapping. Ten cities around the world in different geographical and environmental conditions were selected as study areas. Large volumes of Sentinel-1A SAR and Sentinel-2A MSI data were acquired during the vegetation season in 2015 and 2016. The urban extraction results showed that urban areas and small towns could be well extracted using multitemporal Sentinel-1 SAR, Sentinel-2A MSI data and their fusion using the Urban Extractors developed within the project. For urban land cover mapping, multitemporal Sentinel-1A SAR data alone yielded an overall classification accuracy of 60% for Stockholm. Sentinel-2A MSI data as well as the fusion of Sentinel-1A SAR and Sentinel-2A MSI data, however, produced much higher classification accuracies, both reached 80%.

  • 21.
    Ban, Yifang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Yousif, Osama A.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Change detection techniques: A review2016In: Remote Sensing and Digital Image Processing, Springer, 2016, p. 19-43Conference paper (Refereed)
    Abstract [en]

    With its synoptic view and the repeatability, satellite remote sensing can provide timely, accurate and consistent information about earth’s surface for costeffective monitoring of environmental changes. In this chapter, recent development in change detection techniques using multitemporal remotely sensed images were reviewed. The chapter covers change detection methods for both optical and SAR images. Various aspects of change detection processes were presented including data preprocessing, change image generation and change detection algorithms such as unsupervised and supervised change detection as well as pixel-based and objectbased change detection. The review shows that significant progress has been made in the field of change detection and innovative methods have been developed for change detection using both multitemporal SAR and optical data. Attempts have been made for change detection using multitemporal multisensor/cross-sensor images. The review also identified a number of challenges and opportunities in change detection.

  • 22.
    Ban, Yifang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Yousif, Osama
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Hu, Hongtao
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Fusion of SAR and Optical Data for Urban Land Cover Mapping and Change Detection2014In: Global Urban Monitoring and Assessment through Earth Observation / [ed] Qihao Weng, CRC Press, 2014Chapter in book (Refereed)
  • 23. Belloni, V.
    et al.
    Ravanelli, R.
    Nascetti, Andrea
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics. University of Rome La Sapienza, Rome, Italy.
    Di Rita, M.
    Mattei, D.
    Crespi, M.
    Digital image correlation from commercial to FOS software: A mature technique for full-field displacement measurements2018In: International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives, International Society for Photogrammetry and Remote Sensing , 2018, Vol. 42, no 2, p. 91-95Conference paper (Refereed)
    Abstract [en]

    In the last few decades, there has been a growing interest in studying non-contact methods for full-field displacement and strain measurement. Among such techniques, Digital Image Correlation (DIC) has received particular attention, thanks to its ability to provide these information by comparing digital images of a sample surface before and after deformation. The method is now commonly adopted in the field of civil, mechanical and aerospace engineering and different companies and some research groups implemented 2D and 3D DIC software. In this work a review on DIC software status is given at first. Moreover, a free and open source 2D DIC software is presented, named py2DIC and developed in Python at the Geodesy and Geomatics Division of DICEA of the University of Rome "La Sapienza"; its potentialities were evaluated by processing the images captured during tensile tests performed in the Structural Engineering Lab of the University of Rome "La Sapienza" and comparing them to those obtained using the commercial software Vic-2D developed by Correlated Solutions Inc, USA. The agreement of these results at one hundredth of millimetre level demonstrate the possibility to use this open source software as a valuable 2D DIC tool to measure full-field displacements on the investigated sample surface.

  • 24.
    Börjesson, Alexandra
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Askerson, Mattias
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Suitability Analysis for Expanding Companies2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    When companies are expanding, they are searching for optimal locations according to parameters which are important for the company. Companies for which the geographic location is important needs to rely on geographic aspects to find the optimal site for their service. The geographic tool of using Suitability Analysis can make the planning of expansions more efficient. Is it possible to give a reliable Suitability Analysis and will it differ between different choices of weighting techniques in the analysis?

    The focus of the study is on the reliability of Suitability Analysis for expanding companies depending on geographic data. It will, through a study on a start-up company, be checked if the Suitability Analysis is different between two frequently used weighting ideas; Analytic Hierarchy Process and Swing Weight Technique, in this type of analysis. The Suitability Analysis will be done using Geographical Information Systems and the result will be two suitability maps.

    The study results in two different suitability maps, one for each weighting technique, with differences. The different techniques are dissimilar in their subjectivity of the weighting, which is reflected in the result.

    Suitability Analysis is useful for companies which expansions are depending on geographic aspect. The key to a reliable and useful suitability analysis is depending on a credible source of data for respectively parameter of interest. It decreases the risk of error sources and gives the result a higher reliability. 

  • 25.
    Cai, Zipan
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Multitemporal Satellite Data for Monitoring Urbanization in Nanjing from 2001 to 20162017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Along with the increasing rate of urbanization takes place in the world, the population keeps shifting from rural to urban areas. China, as the country of the largest population, has the highest urban population growth in Asia, as well as the world. However, the urbanization in China, in turn, is leading to a lot of social issues which reshape the living environment and cultural fabric. A variety of these kinds of social issues emphasize the challenges regarding a healthy and sustainable urban growth particularly in the reasonable planning of urban land use and land cover features. Therefore, it is significant to establish a set of comprehensive urban sustainable development strategies to avoid detours in the urbanization process.

    Nowadays, faced with such as a series of the social phenomenon, the spatial and temporal technological means including Remote Sensing and Geographic Information System (GIS) can be used to help the city decision maker to make the right choices. The knowledge of land use and land cover changes in the rural and urban area assists in identifying urban growth rate and trend in both qualitative and quantitatively ways, which provides more basis for planning and designing a city in a more scientific and environmentally friendly way. This paper focuses on the urban sprawl analysis in Nanjing, Jiangsu, China that being analyzed by urban growth pattern monitoring during a study period.

    From 2001 to 2016, Nanjing Municipality has experienced a substantial increase in the urban area because of the growing population. In this paper, one optimal supervised classification with high accuracy which is Support Vector Machine (SVM) classifier was used to extract thematic features from multitemporal satellite data including Landsat 7 ETM+, Landsat 8, and Sentinel-2A MSI. It was interpreted to identify the existence of urban sprawl pattern based on the land use and land cover features in 2001, 2006, 2011, and 2016. Two different types of change detection analysis including post-classification comparison and change vector analysis (CVA) were performed to explore the detailed extent information of urban growth within the study region. A comparison study on these two change detection analysis methods was carried out by accuracy assessment. Based on the exploration of the change detection analysis combined with the current urban development actuality, some constructive recommendations and future research directions were given at last.

    By implementing the proposed methods, the urban land use and land cover changes were successfully captured. The results show there is a notable change in the urban or built-up land feature. Also, the urban area is increased by 610.98 km2 while the agricultural land area is decreased by 766.96 km2, which proved a land conversion among these land cover features in the study period. The urban area keeps growing in each particular study period while the growth rate value has a decreasing trend in the period of 2001 to 2016. Besides, both change detection techniques obtained the similar result of the distribution of urban expansion in the study area. According to the result images from two change detection methods, the expanded urban or built-up land in Nanjing distributes mainly in the surrounding area of the central city area, both side of Yangtze River, and Southwest area.

    The results of change detection accuracy assessment indicated the post-classification comparison has a higher overall accuracy 86.11% and a higher Kappa Coefficient 0.72 than CVA. The overall accuracy and Kappa Coefficient for CVA is 75.43% and 0.51 respectively. These results proved the strength of agreement between predicted and truth data is at ‘good’ level for post-classification comparison and ‘moderate’ for CVA. Also, the results further confirmed the expectation from previous studies that the empirical threshold determination of CVA always leads to relatively poor change detection accuracy. In general, the two change detection techniques are found to be effective and efficient in monitoring surface changes in the different class of land cover features within the study period. Nevertheless, they have their advantages and disadvantages on processing change detection analysis particularly for the topic of urban expansion.

  • 26.
    Carlbark, Terese
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Hirsch, Magdalena
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    NNH - ur Stockholms läns kommuners perspektiv2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 27. Cartalis, C.
    et al.
    Asimakopoulos, D. N.
    Ban, Yifang
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Bao, Y.
    Bi, Y.
    Defourny, P.
    Del Barrio, G.
    Fan, J.
    Gao, Z.
    Gong, H.
    Gong, J.
    Gong, P.
    Li, C.
    Pignatti, S.
    Sarris, A.
    Yang, G.
    Earth observation in support of science and applications development in the field "land and Environment": Synthesis results from the ESA-most dragon cooperation Programme2015In: International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives, 2015, no 7W3, p. 1075-1081Conference paper (Refereed)
    Abstract [en]

    Dragon is a cooperation Programme between the European Space Agency (ESA) and the Ministry of Science and Technology (MOST) of the P.R. China. The Programme, initiated in 2004, focuses on the exploitation of ESA, Third Party Missions (TPM) and Chinese Earth Observation (EO) data for geo-science and applications development in land, ocean and atmospheric applications. In particular, the Programme brings together joint Sino- European teams to investigate 50 thematic projects. In this paper, the results of the research projects1 in the thematic field "Land and Environment" will be briefly presented, whereas emphasis will be given in the assessment of the usefulness of the results for an integrated assessment of the state of the environment in the respective study areas. Furthermore new knowledge gained in such fields as desertification assessment, drought and epidemics' monitoring, forest modeling, cropwatch monitoring, climate change vulnerability (including climate change adaptation and mitigation plans), urbanization monitoring and land use/cover change assessment and monitoring, will be presented. Such knowledge will be also linked to the capacities of Earth Observation systems (and of the respective EO data) to support the temporal, spatial and spectral requirements of the research studies. The potential of DRAGON to support such targets as "technology and knowledge transfer at the bilateral level", "common EO database for exploitation" and "data sharing and open access data policy" will be also presented. Finally special consideration will be given in highlighting the replication potential of the techniques as developed in the course of the projects, as well as on the importance of the scientific results for environmental policy drafting and decision making.

  • 28. Claesson, A.
    et al.
    Fredman, D.
    Svensson, L.
    Ringh, M.
    Hollenberg, J.
    Nordberg, P.
    Rosenqvist, M.
    Djarv, T.
    Österberg, S.
    Lennartsson, J.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Ban, Yifang
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Unmanned aerial vehicles (drones) in out-of-hospital-cardiac-arrest2016In: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, ISSN 1757-7241, E-ISSN 1757-7241, Vol. 24, no 1, article id 124Article in journal (Refereed)
    Abstract [en]

    Background: The use of an automated external defibrillator (AED) prior to EMS arrival can increase 30-day survival in out-of-hospital cardiac arrest (OHCA) significantly. Drones or unmanned aerial vehicles (UAV) can fly with high velocity and potentially transport devices such as AEDs to the site of OHCAs. The aim of this explorative study was to investigate the feasibility of a drone system in decreasing response time and delivering an AED. Methods: Data of Global Positioning System (GPS) coordinates from historical OHCA in Stockholm County was used in a model using a Geographic Information System (GIS) to find suitable placements and visualize response times for the use of an AED equipped drone. Two different geographical models, urban and rural, were calculated using a multi-criteria evaluation (MCE) model. Test-flights with an AED were performed on these locations in rural areas. Results: In total, based on 3,165 retrospective OHCAs in Stockholm County between 2006-2013, twenty locations were identified for the potential placement of a drone. In a GIS-simulated model of urban OHCA, the drone arrived before EMS in 32 % of cases, and the mean amount of time saved was 1.5 min. In rural OHCA the drone arrived before EMS in 93 % of cases with a mean amount of time saved of 19 min. In these rural locations during (n = 13) test flights, latch-release of the AED from low altitude (3-4 m) or landing the drone on flat ground were the safest ways to deliver an AED to the bystander and were superior to parachute release. Discussion: The difference in response time for EMS between urban and rural areas is substantial, as is the possible amount of time saved using this UAV-system. However, yet another technical device needs to fit into the chain of survival. We know nothing of how productive or even counterproductive this system might be in clinical reality. Conclusions: To use drones in rural areas to deliver an AED in OHCA may be safe and feasible. Suitable placement of drone systems can be designed by using GIS models. The use of an AED equipped drone may have the potential to reduce time to defibrillation in OHCA.

  • 29.
    Duc, Khanhngo
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment.
    Vu, T.
    Ban, Yifang
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Ushahidi and Sahana Eden Open-Source Platforms to Assist Disaster Relief: Geospatial Components and Capabilities2014In: Geoinformation for Informed Decisions, Springer, 2014, Vol. 199679, p. 163-174Conference paper (Refereed)
    Abstract [en]

    In responses to recent large-scale disaster events, huge amount of ground information have been collected in addition to the synoptic views from satellite images. Different platforms have been in place to facilitate the collection and management of such critical location-based information from the crowd. This study investigated the current implementation of geospatial components and their capabilities in open-source platforms, particularly Ushahidi and Sahana Eden. Using the 2011 Christchurch earthquake data and following the four main functions of a geo-info system: Data input, Geospatial analysis, Data management, and Visualization, the performance of geospatial-components were evaluated by a group of users. The result showed that with rich visualization on interactive map both Sahana Eden and Ushahidi enable emergency managers to track the needs of disaster-affected people. While Ushahidi can only filter incidents records by time or category, geospatial data management of Sahana Eden is proven to be more powerful, allowing emergency managers input different geospatial data such as incidents, organizations, human resource, warehouses, hospitals, shelters, assets, and projects and visualizing all of these features on a map. It also helps to simplify the coordination among aids agencies. However, geospatial analysis is the limitation of both platforms. The findings recommended that data input with more variety of formats and more geospatial analysis functions should be added. Further research will expand to more case studies taking into account the requirements of disaster management practitioners and emergency responders.

  • 30.
    Eduards, Rasmus
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Current and Potential Use of Linked Geodata2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    As of Today (2017) Geographic Information (GI) is a vital part of our daily life. With different applications like Google Maps it is hard to not get in contact with these platforms. Applications like Google are becoming more than just maps for us to find our way in the real world, they contain important data. As of now some of these datasets are kept by authorities and institutes with no connection to each other. One way to link this information to each other is by using Linked Data and more specifically when it comes to GI, Linked Geodata. By linking data together, information becomes connected, which can help the structure of Open Data and other data collaborates. It also enables ways to query the data to for example in search engines.

    This Bachelor of Science thesis has been conducted at KTH Royal Institute of Technology, in cooperation with Digpro AB. This thesis purpose is to examine whether the Linked Geodata is something to invest in. This was done by investigating current use to understand how Linked Geodata is implemented, as well to describe challenges and possibilities in respect to Linked Geodata. This is done by literature review and through interviews with personnel working with implementation of Linked Geodata.

    The result showed some implementations in the Netherlands and in Finland, also a private initiative from the University of Leipzig called LinkedGeoData. In Sweden authorities had explored the topic of Linked Geodata without any actual attempts to implement it. The biggest challenges was that queries did not supported all kind of spatial data, maintain the Linked Geodata consistent and find a way to fund the workload. The biggest possibilities were to create cooperation between authorities, integration and discoverability of data in search engines and to improve the environment for publishing open data, which could lead to an improved social and economic situation.

    After evaluation this thesis concludes that there is a lot of potential use for Linked Geodata. The most considerable possible use is for authorities with a larger amount of geodata especially regarding their publishing of Open Data and integrating their data to search engines to provide more advanced queries. The technology seems to have some problems, mainly the lack of support for spatial data and also problems with maintaining the connections. However the problems are not too severe in order to not invest in the technology. The technology just needs some improvements and more initiatives.

  • 31.
    Ekroth, Natalie
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Evaluation of Thermal Images for Detecting Leakages in District Heating Networks: A Case Study in Örebro City2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Leakages in the district heating networks is a current and growing problem. To find the leakages today many district heating companies uses manual techniques that are both time consuming and insecure, the methods can leave a lot of leakages in older pipes undiscovered for a very long time. These undetected leakages costs the district heating companies a lot of money and can even be fatal. It is therefor of great importance that the leakages is found in time, thus the methods for leak detection needs to be improved.

    The main purpose of this thesis was to investigate the ability to use thermal images to automatically search for leakages in district heating systems. To investigate this aerial thermal images from 2013 were collected. Image analysis was performed using ArcGIS and ENVI. This included, among other things, image preprocessing such as to define the projection of the images and unsupervised isodata classification to find potential leakages in the thermal images.

    This automatic analysis resulted in many false alarms. One example were false alarms caused by vegetation, since vegetation absorbs heat during the day it appears warmer than the surroundings at night. To deal with this problem an unsupervised classification algorithm, isodata, was used again to classify the vegetational areas and the non-vegetational. This algorithm decreased the number of false alarms drastic and thereby increased the usability of the algorithm.

    Other false alarm that has not been automatically rejected in this thesis were for example false alarms caused by heat leaking from buildings. One way to map such false alarms could be to analyse the shape and the linearisation of the potential leakages close to buildings. This would hugely increase the accuracy of the used algorithm.

    The provided thermal images used in this thesis consisted of several confirmed leakages. All these confirmed leakages was found by the used algorithm. Although, the accuracy of the used algorithm could be discussed since many false alarms were generated. Nevertheless, to reject false alarms are much less time consuming than manual leak detection for an entire city. Thereby the conclusion that an automatic leak detection in district heating networks is possible, furthermore a leak detection tool like this would be usable for the district heating companies.

    The evaluations from several different district heating experts who are using Digpro's district heating application, dpHeating, today shows that a leak detection tool using thermal images would be a useful addition in dpHeating.

  • 32.
    Ekroth, Natalie
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Lennartsson, Josefin
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Web-based Multicriteria Decision Analysis and Visualization for Reinvestments in Power Networks2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    It can be a hard and time consuming task for a decision maker to decide which parts of a network to reinvest in. There are a lot of parameters to take into consideration regarding reinvestments, for example age, number of outages, number of inspection remarks and the degree of inspection remarks. Without any visualization, it is difficult to detect patterns in the data. Therefor, the decision maker is required to really know the network he/she is working with and to have a gut feeling of where to reinvest.

    The purpose of this thesis is to show that the decision making process can be much simpler and better supported when using GIS tools for analysis and visualization. This is done by designing a prototype of a web application that can produce multicriteria decision analysis on the parameters of interest for reinvestments in a power network.Traditionally, heavy desktop clients are for expert users while web-based clients are better for layman users. One of the greatest advantages of a web-based client over a desktop client is that it can be reached externally from any device that has access to internet. Because of this, the prototype is developed as a web-based client. Customer data can be sensitive information, this means that the data needs to be secure and directly accessible for the users of the application. Therefor, a 3-tier architecture with client, server and database is used.

    The result is visualized in a map, which makes it easy for anyone to interpret the result. Since the prototype is developed to be used by none GIS experts, the weighted linear combination method is used for the analysis. The prototype is not fully automated and does not deliver an absolute decision, the goal is rather for it to function as an aid for the decision maker when deciding on the final reinvestment area.

    The prototype is evaluated by the prospective users of the application through a questionnaire and the results show that a tool like this would be very useful for reinvestments decisions. Since the prototype does not rely on topology or network structure, it can be adapted to other spatial decision problems than just reinvestments in power networks.

  • 33.
    Fanting, Gong
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Linking socio-economic factors to urban growth by using night timelight imagery from 1992 to 2012: A case study in Beijing2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In recent decades, the night lights data of the Earth’s surface derived from the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP/OLS) have been used to detect the human settlements and human activities, because the DMSP/OLS data is able to supply the information about the urban areas  and non-urban areas on the Earth which means it is more suitable for urban studies than usual satellite imagery data.

     

    The urban development is closed linked to the human society development. Therefore, studies of urban development will help people to understand how the urban changed and predict the urban change. The aim of this study was to detect Beijing’s urban development from 1992 to 2012, and find the contributions to the urban sprawl from socio-economic factors. Based on this objective, the main dataset used in this thesis was night lights images derived from the DMSP/OLS which was detected from  1992 to 2012. Due to the lacking of on-board calibration on OLS, and the over-glow of the lights resources, the information about the night lights cannot be extracted directly. Before any process, the night lights images should be calibrated. There is a method to calibrate the night light images which is called intercalibration. It is a second order regression model based method to find the related digital number values. Therefore, intercalibration was employed, and the threshold values were determined to extract urban areas in this study. Threshold value is useful for diffusing the over-glow effect, and finding the urban areas from the DMSP/OLS data. The methods to determine the threshold value in this thesis are empirical threshold method, sudden jump detection method, statistic data comparison method and k-mean clustering method. In addition, 13 socio-economic factors which included gross domestic product, urban population, permanent population, total energy consumption and so on were used to build the regression model. The contributions from these factors to the sum of the Beijing’s lights were found based on modeling.

     

    The results of this thesis are positive. The intercalibration was successful and all the DMSP/OLS data used in this study were calibrated. And then, the appropriate threshold values to extract the urban areas were figured out. The achieved urban areas were compared to the satellite images and the result showed that the urban areas were useful. During the time certain factors used in this study, such as mobile phone users, possession of civil vehicles, GDP, three positively highest contributed to urban development were close to 23%, 8% and 9%, respectively.

  • 34. Fredman, D.
    et al.
    Haas, Jan
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Ban, Yifang
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Jonsson, M.
    Svensson, L.
    Djarv, T.
    Hollenberg, J.
    Nordberg, P.
    Ringh, M.
    Claesson, A.
    Use of a geographic information system to identify differences in automated external defibrillator installation in urban areas with similar incidence of public out-of-hospital cardiac arrest: A retrospective registry-based study2017In: BMJ Open, ISSN 2044-6055, E-ISSN 2044-6055, Vol. 7, no 5, article id e014801Article in journal (Refereed)
    Abstract [en]

    Objectives Early defibrillation in out-of-hospital cardiac arrest (OHCA) is of importance to improve survival. In many countries the number of automated external defibrillators (AEDs) is increasing, but the use is low. Guidelines suggest that AEDs should be installed in densely populated areas and in locations with many visitors. Attempts have been made to identify optimal AED locations based on the incidence of OHCA using geographical information systems (GIS), but often on small datasets and the studies are seldom reproduced. The aim of this paper is to investigate if the distribution of public AEDs follows the incident locations of public OHCAs in urban areas of Stockholm County, Sweden. Method OHCA data were obtained from the Swedish Register for Cardiopulmonary Resuscitation and AED data were obtained from the Swedish AED Register. Urban areas in Stockholm County were objectively classified according to the pan-European digital mapping tool, Urban Atlas (UA). Furthermore, we reclassified and divided the UA land cover data into three classes (residential, non-residential and other areas). GIS software was used to spatially join and relate public AED and OHCA data and perform computations on relations and distance. Results Between 1 January 2012 and 31 December 2014 a total of 804 OHCAs occurred in public locations in Stockholm County and by December 2013 there were 1828 AEDs available. The incidence of public OHCAs was similar in residential (47.3%) and non-residential areas (43.4%). Fewer AEDs were present in residential areas than in non-residential areas (29.4% vs 68.8%). In residential areas the median distance between OHCAs and AEDs was significantly greater than in non-residential areas (288 m vs 188 m, p<0.001). Conclusion The majority of public OHCAs occurred in areas classified in UA as 'residential areas' with limited AED accessibility. These areas need to be targeted for AED installation and international guidelines need to take geographical location into account when suggesting locations for AED installation.

  • 35. Fredman, D.
    et al.
    Svensson, L.
    Ban, Yifang
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Jonsson, M.
    Hollenberg, J.
    Nordberg, P.
    Ringh, M.
    Rosenqvist, M.
    Lundén, M.
    Claesson, A.
    Expanding the first link in the chain of survival – Experiences from dispatcher referral of callers to AED locations2016In: Resuscitation, ISSN 0300-9572, E-ISSN 1873-1570, Vol. 107, p. 129-134Article in journal (Refereed)
    Abstract [en]

    Introduction Early use of automated external defibrillators (AED) increases survival in cases of out-of-hospital cardiac arrest (OHCA). Dispatchers play important roles in identifying OHCA, dispatching ambulances and providing callers with telephone-assisted cardiopulmonary resuscitation. Guidelines recommend that AED registries be linked to dispatch centres as tools to refer callers to nearby AED. Aim The aim of this study was to investigate to what extent dispatchers, when provided with a tool to display AED locations and accessibility, referred callers to nearby AED. Methods An application providing real-time visualization of AED locations and accessibility was implemented at four dispatch centres in Sweden. Dispatchers were instructed to refer callers to nearby AED when OHCA was suspected. Such cases were prospectively collected, and geographic information systems were used to identify those located ≤100 m from an AED. Audio recordings of emergency calls were assessed to evaluate the AED referral rate. Results Between February and August 2014, 3009 suspected OHCA calls were received. In 6.6% of those calls (200/3009), an AED was ≤100 m from the suspected OHCA. The AED was accessible and the caller was not alone on scene in 24% (47/200) of these cases. In two of those 47 cases (4.3%), the dispatcher referred the caller to the AED. Conclusion Despite a tool for dispatchers to refer callers to a nearby AED, referral was rare. Only a minority of the suspected OHCA cases occurred ≤100 m from an AED. We identified AED accessibility and callers being alone on scene as obstacles for AED referral.

  • 36.
    Gadhoumi, Shérazade
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics. Airbus Defence & Space.
    Platforms for Real-time Moving Object Location Stream Processing2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Boarder security is usually based on observing and analyzing the movement of MovingPoint Objects (MPOs): vehicle, boats, pedestrian or aircraft for example. This movementanalysis can directly be made by an operator observing the MPOs in real-time, but theprocess is time-consuming and approximate. This is why the states of each MPO (ID, location,speed, direction) are sensed in real-time using Global Navigation Satellite System(GNSS), Automatic Identification System (AIS) and radar sensing, thus creating a streamof MPO states. This research work proposes and carries out (1) a method for detectingfour different moving point patterns based on this input stream (2) a comparison betweenthree possible implementations of the moving point pattern detectors based on three differentData Stream Management Systems (DSMS). Moving point patterns can be dividedin two groups: (1) individual location patterns are based on the analysis of the successivestates of one MPO, (2) set-based relative motion patterns are based on the analysis ofthe relative motion of groups of MPOs within a set. This research focuses on detectingfour moving point patterns: (1) the geofence pattern consists of one MPO enteringor exiting one of the predefined areas called geofences, (2) the track pattern consists ofone MPO following the same direction for a given number of time steps and satisfying agiven spatial constraint, (3) the flock pattern consists of a group of geographically closeMPOs following the same direction, (4) the leadership pattern consists of a track patternwith the corresponding MPO anticipating the direction of geographically close MPOs atthe last time step. The two first patterns are individual location patterns, while the othersare set-based relative motion patterns. This research work proposes a method for detectinggeofence patterns based on the update of a table storing the last sensed state of eachMPO. The approach used for detecting track, flock and leadership patterns is based on theupdate of a REMO matrix (RElative MOtion matrix) where rows correspond to MPOs,columns to time steps and cells record the direction of movement. For the detection offlock patterns a simple but effective probabilistic grid-based approach is proposed in orderto detect clusters of MPOs within the MPOs following the same direction: (1) the Filteringphase partitions the study area into square-shaped cells -according to the dimensionof the spatial constraint- and selects spatially contiguous grid cells called candidate areasthat potentially contain flock patterns (2) for each candidate area, the Refinement phasegenerates disks of the size of the spatial constraint within the selected area until one diskcontains enough MPOs, so that the corresponding MPOs are considered to build a flockpattern. The pattern detectors are implemented on three DSMSs presenting differentcharacteristics: Esri ArcGIS GeoEvent Extension for Server (GeoEvent Ext.), a workflow-based technology that ingests each MPO state separately, Apache Spark Streaming(Spark), a MapReduce-based technology that processes the input stream in batches in ahighly-parallel processing framework and Apache Flink (Flink), a hybrid technology thatingests the states separately but offers several MapReduce semantics. GeoEvent Ext. onlylends itself for a nature implementation of the geofence detector, while the other DSMSsaccommodate the implementation of all detectors. Therefore, the geofence, track, flockand leadership pattern detectors are implemented on Spark and Flink, and empiricallyevaluated in terms of scalability in time/space based on the variation of parameters characterizingthe patterns and/or the input stream. The results of the empirical evaluationshows that the implementation on Flink uses globally less computer resources than theone on Spark. Moreover, the program based on Flink is less sensitive to the variability ofparameters describing either the input stream or the patterns to be detected.

  • 37.
    Gebresilassie, Mesele Atsbeha
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Spatio-temporal Traffic Flow Prediction2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The advancement in computational intelligence and computational power and the explosionof traffic data continues to drive the development and use of Intelligent TransportSystem and smart mobility applications. As one of the fundamental components of IntelligentTransport Systems, traffic flow prediction research has been advancing from theclassical statistical and time-series based techniques to data–driven methods mainly employingdata mining and machine learning algorithms. However, significant number oftraffic flow prediction studies have overlooked the impact of road network topology ontraffic flow. Thus, the main objective of this research is to show that traffic flow predictionproblems are not only affected by temporal trends of flow history, but also by roadnetwork topology by developing prediction methods in the spatio-temporal.In this study, time–series operators and data mining techniques are used by definingfive partially overlapping relative temporal offsets to capture temporal trends in sequencesof non-overlapping history windows defined on stream of historical record of traffic flowdata. To develop prediction models, two sets of modeling approaches based on LinearRegression and Support Vector Machine for Regression are proposed. In the modelingprocess, an orthogonal linear transformation of input data using Principal ComponentAnalysis is employed to avoid any potential problem of multicollinearity and dimensionalitycurse. Moreover, to incorporate the impact of road network topology in thetraffic flow of individual road segments, shortest path network–distance based distancedecay function is used to compute weights of neighboring road segment based on theprinciple of First Law of Geography. Accordingly, (a) Linear Regression on IndividualSensors (LR-IS), (b) Joint Linear Regression on Set of Sensors (JLR), (c) Joint LinearRegression on Set of Sensors with PCA (JLR-PCA) and (d) Spatially Weighted Regressionon Set of Sensors (SWR) models are proposed. To achieve robust non-linear learning,Support Vector Machine for Regression (SVMR) based models are also proposed.Thus, (a) SVMR for Individual Sensors (SVMR-IS), (b) Joint SVMR for Set of Sensors(JSVMR), (c) Joint SVMR for Set of Sensors with PCA (JSVMR-PCA) and (d) SpatiallyWeighted SVMR (SWSVMR) models are proposed. All the models are evaluatedusing the data sets from 2010 IEEE ICDM international contest acquired from TrafficSimulation Framework (TSF) developed based on the NagelSchreckenberg model.Taking the competition’s best solutions as a benchmark, even though different setsof validation data might have been used, based on k–fold cross validation method, withthe exception of SVMR-IS, all the proposed models in this study provide higher predictionaccuracy in terms of RMSE. The models that incorporated all neighboring sensorsdata into the learning process indicate the existence of potential interdependence amonginterconnected roads segments. The spatially weighted model in SVMR (SWSVMR) revealedthat road network topology has clear impact on traffic flow shown by the varyingand improved prediction accuracy of road segments that have more neighbors in a closeproximity. However, the linear regression based models have shown slightly low coefficientof determination indicating to the use of non-linear learning methods. The resultsof this study also imply that the approaches adopted for feature construction in this studyare effective, and the spatial weighting scheme designed is realistic. Hence, road networktopology is an intrinsic characteristic of traffic flow so that prediction models should takeit into consideration.

  • 38.
    Gidofalvi, Gyözö
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Yang, Can
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Scalable Detection of Traffic Congestion from Massive Floating Car Data Streams2015Conference paper (Refereed)
    Abstract [en]

    Motivated by the high utility and growing availability of Floating Car Data (FCD) streams for traffic congestion modeling and subsequent traffic congestion-related intelligent traffic management tasks, this paper proposes a grid-based, time-inhomogeneous model and method for the detection of congestion from large FCD streams. Furthermore, the paper proposes a simple but effective, high-level implementation of the method using off-the-shelf relational database technology that can readily be ported to Big Data processing frameworks. Empirical evaluations on millions of real-world taxi trajectories show that 1) the spatio-temporal distribution and clustering of the detected congestions are reasonable and 2) the method and its prototype implementation scale linearly with the input size and the geographical level of detail / spatio-temporal resolution of the model.

  • 39.
    Gustafsson, Klas
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Berg, Oskar
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    2D and 3D Visualization to Support Fieldwork in the Area of Utility Networks2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Utility network fieldworkers of today want to access more information and can benefit a lot from new technical development. Today most fieldwork is conducted using paper plans or locally stored data on laptops as a visual aid. Therefore there is a need for improvement and development of new reliable software for fieldwork. Also the abil- ity to use advanced Geographic Information Systems (GIS) solutions and enhanced visualization methods while out in the field could help improve fieldwork. In order to be as e↵ective as possible when carrying out di↵erent tasks in the field, di↵erent ways of visualizing the same network data are required. 2D and 3D visualization methods have di↵erent advantages and disadvantages when it comes to visualizing network data, which will be accounted for in this thesis.

    There are three main objectives in this thesis. The first is to evaluate how suitable di↵erent visualization methods are for fieldwork users working with utility networks. The second is to get a better understanding of what hardware and software that can be used for implementing the visualization methods. The last one is to use the first and second objectives to develop a prototype for utility network fieldwork.

    To address the objectives, the first step is to understand the users that work in the field. By conducting interviews, information about the current workflow for fieldworkers and their opinions about how the systems currently work is gathered. Based on this information the thesis is divided into cases and criteria which is the foundation for proposing a solution in form of mock-up sketches which is then imple- mented in form of a prototype. Finally the prototype is evaluated quantitatively and qualitatively using a web survey and presentations for potential end users.

    The prototype is created using web technologies and is mainly intended for tablets. Because of its mobility, screen size and adequate computational power the tablet is a good hardware choice for conducting fieldwork. The prototype presents network data in a 2D interactive map view, a 3D augmented reality (AR) view and a combined view. These choices are based on information gathered by studying related work and performing interviews with potential end users in the beginning of the study.

    The results of the thesis highlights large possibilities in making field work more e↵ective for fieldworkers. This in concluded partly by the results of the interviews with potential end users, but also by the response of the survey and presentation of the suggested solution. It is shown that there are new ways to improve the work process out in the field and that AR can help in visualizing the network in a new informative way for fieldwork. However, several challenges remain, but rapid techno- logical development implies possible solutions to deal with these challenges. 

  • 40. Haas, J.
    et al.
    Ban, Yifang
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Sentinel-1A SAR and sentinel-2A MSI data fusion for urban ecosystem service mapping2017In: Remote Sensing Applications: Society and Environment, ISSN 2352-9385, Vol. 8, p. 41-53Article in journal (Refereed)
    Abstract [en]

    The two main objectives of this study are to evaluate the potential use and synergetic effects of ESA Sentinel-1A C-band SAR and Sentinel-2A MSI data for classification and mapping of ecologically important urban and peri-urban space and to introduce spatial characteristics into ecosystem service analyses based on remotely sensed data. Image resolutions between 5 m and 20 m provided by the Sentinel satellites introduce a new relevant spatial scale in-between high and medium resolution data at which not only urban areas but also their important hinterlands can be effectively and efficiently mapped. Sentinel-1/2 data fusion facilitates both the capture of ecologically relevant details while at the same time also enabling large-scale urban analyses that draw surrounding regions into consideration. The combined use of Sentinel-1A SAR in Interferometric Wide Swath mode and simulated Sentinel-2A MSI (APEX) data is being evaluated in a classification of the Zürich metropolitan area, Switzerland. The SAR image was terrain-corrected, speckle-filtered and co-registered to the simulated Sentinel-2 image. After radiometric and spatial resampling, the fused image stack was segmented and classified by SVM. After post-classification, landscape elements were investigated in terms of spatial characteristics and topological relations that are believed to influence ecosystem service supply and demand, i.e. area, contiguity, perimeter-to-area ratio and distance. Based on the classification results, ecosystem service supplies and demands accounting for spatial and topological patch characteristics were attributed to 14 land cover classes. The quantification of supply and demand values resulted in a positive ecosystem service budget for Zürich. The spatially adjusted service budgets and the original budgets are similar from a landscape perspective but deviate up to 50% on the patch level. The introduction of spatial and topological patch characteristics gives a more accurate impression of ecosystem service supply and demands and their distributions, thus enabling more detailed analyses in complex urban surroundings. The method and underlying data are considered suitable for urban land cover and ecosystem service mapping and the introduction of spatial aspects into relative ecosystem service valuation concepts is believed to add another important aspect in currently existing approaches.

  • 41.
    Haas, Jan
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Remote Sensing of Urbanization and Environmental Impacts2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis aims to establish analytical frameworks to map urban growth patterns with spaceborne remote sensing data and to evaluate environmental impacts through Landscape Metrics and Ecosystem Services. Urbanization patterns at regional scale were evaluated in China's largest urban agglomerations and at metropolitan scale in Shanghai, Stockholm and Beijing using medium resolution optical satellite data. High-resolution data was used to investigate changes in Shanghai’s urban core. The images were co-registered and mosaicked. Tasseled Cap transformations and texture features were used to increase class separabilities prior to pixel-based Random Forest and SVM classifications. Urban land cover in Shanghai and Beijing were derived through object-based SVM classification in KTH-SEG. After post-classification refinements, urbanization indices, Ecosystem Services and Landscape Metrics were used to quantify and characterize environmental impact. Urban growth was observed in all studies. China's urban agglomerations showed most prominent urbanization trends. Stockholm’s urban extent increased only little with minor environmental implications. On a regional/metropolitan scale, urban expansion progressed predominately at the expense of agriculture. Investigating urbanization patterns at higher detail revealed trends that counteracted negative urbanization effects in Shanghai's core and Beijing's urban-rural fringe. Beijing's growth resulted in Ecosystem Services losses through landscape structural changes, i.e. service area decreases, edge contamination or fragmentation. Methodological frameworks to characterize urbanization trends at different scales based on remotely sensed data were developed. For detailed urban analyses high-resolution data are recommended whereas medium-resolution data at metropolitan/regional scales is suggested. The Ecosystem Service concept was extended with Landscape Metrics to create a more differentiated picture of urbanization effects.​

  • 42.
    Haas, Jan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Ban, Yifang
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Mapping and Moitoring Urban Ecosystem Services Using High-Resolution Satellite DataManuscript (preprint) (Other academic)
  • 43.
    Haas, Jan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Ban, Yifang
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Mapping and Monitoring Urban Ecosystem Services Using Multitemporal High-Resolution Satellite Data2016In: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, ISSN 1939-1404, E-ISSN 2151-1535, Vol. 10, no 2, p. 669-680Article in journal (Refereed)
    Abstract [en]

    This study aims at providing a new method to efficiently analyse detailed urban ecological conditions at the example of Shanghai, one of the world’s most densely populated megacities. The main objective is to develop a method to effectively analyse high-resolution optical satellite data for mapping of ecologically important urban space and to evaluate ecological changes through the emerging ecosystem service supply and demand budget concept. Two IKONOS and GeoEye-1 scenes were used to determine land use/land cover change in Shanghai's urban core from 2000 to 2009. After pre-processing, the images were segmented and classified into seven distinct urban land use/land cover classes through SVM. The classes were then transformed into ecosystem service supply and demand budgets based on ecosystem functions. Decreases of continuous urban fabric and industrial areas in the favour of urban green sites and high-rise areas with commercial/residential function could be observed resulting in an increase of at least 20% in service supply budgets. Main contributors to the change are mainly the decrease of continuous urban fabric and industrial areas. The overall results and outcome of the study strengthen the suggested application of the proposed method for urban ecosystem service budget mapping with hitherto for that purpose unutilized high-resolution data. The insights and results from this study might further contribute to sustainable urban planning, prove common grounds for inter-urban comparisons or aid in enhancing ecological intra-urban functionality by analysing the distribution of urban eco-space and lead to improved accessibility and proximity to ecosystem services in urban areas

  • 44.
    Haas, Jan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Ban, Yifang
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Spatio-temporal urban ecosystem service analysis with Sentinel-2A MSI dataManuscript (preprint) (Other academic)
    Abstract [en]

    Continuous urbanization changes the surface of our globe raising questions of sustainability, ecological functionality and living quality in metropolitan regions. Remote sensing enables us to obtain timely and reliable information on the state of urban areas and their changing patterns. The objectives of this study are to evaluate the contribution of Sentinal-2A data for urban ecosystem service mapping and to evaluate spatio-temporal characteristics of ecosystem service provisional patches through landscape metrics as an extension of the ecosystem service concept. Changes in service patterns over a 10-year time frame are mapped in the megacity of Beijing, China using Landsat TM data from 2005 and Sentinel-2A data from 2015. Landscape metrics are generated based on the classification results to evaluate the changes of urban ecosystem service provision bundles. The images are segmented using KTH-SEG, an edge-aware region growing and merging algorithm. The segments are then classified using a SVM classifier according to a classification strategy that is designed to distinguish between four natural and managed urban classes based on underlying ecosystem function and three artificial urban structures, i.e. buildings and roads that negatively influence ecosystem service provision to varying degrees and in different ways. These negative impacts are quantified through seven spatial attributes of green and blue patches and their configuration, namely area (CA), connectivity (COHESION), core area (TCA), diversity (SHDI), edge effects (CWED), percentage of land cover (PLAND) and a proximity measure. The 2015 classification accuracy of 90.2% was higher than the 2005 classification accuracy with 84.7%. Beijing’s urban development is characterized by a decrease in agricultural areas in the urban fringe in favour of new high and low density built-up areas, urban green space and golf courses. In total, high density and low-density urban areas have increased ca. 21%. Furthermore, the deconstruction of former high density low-rise suburban agglomerations into urban green space can be observed. The planar increase in urban areas is partly counteracted by the creation of managed urban green spaces. Ecosystem service bundles based on underlying land cover classes and similar spatial factors that influence service quality were derived for 2005 and 2015. Changes in landscape composition and configuration resulted in decreases of more than 30% in the bundles that represent food supply, noise reduction, waste treatment, global climate regulation. Temperature regulation/moderation of climate extremes, recreation/place values and social cohesion, aesthetic benefits/cognitive development and least affected by the observed land cover changes. The extension of the ecosystem service concept through spatio-temporal characteristics of ecosystem service provisional patches by landscape metrics is believed to give a more realistic appraisal of ecosystem services in urban areas.

  • 45.
    Haas, Jan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Ban, Yifang
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Urban Land Cover and Ecosystem Service Changes based on Sentinel-2A MSI and Landsat TM Data2018In: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, ISSN 1939-1404, E-ISSN 2151-1535, Vol. 11, no 2, p. 485-497Article in journal (Refereed)
    Abstract [en]

    Sustainable development in metropolitan regions is challenging in the light of continuous urbanization. Remote sensing provides timely and reliable information on urban areas and their changing patterns. This study's objectives are to evaluate the contribution of Sentinel-2A (S-2A) data to urban ecosystem service mapping and to investigate spatial ecosystem service characteristics with landscape metrics through a novelmethod. Service pattern changes between 2005 and 2015 are mapped for Beijing, China. Landscape metrics are used to qualitatively evaluate urban ecosystem service provision bundle changes. S-2A and Landsat TM data are segmented and classified with SVM, distinguishing three artificial and four natural classes based on ecosystem function. Spatial characteristics influencing ecosystem services are quantified with seven landscape metrics. Beijing's urban development is characterized by reduction in agricultural areas in the urban fringe in favor of built-up areas, urban green space, and golf courses. A transformation of old suburban agglomerations into urban green space can be observed. The planar increase in urban areas is accompanied by the creation of managed urban green space. Service bundles based on land cover classes and spatial characteristics decreased more than 30% for bundles that represent food supply, noise reduction, waste treatment, and global climate regulation. Temperature regulation/moderation of climate extremes, recreation/place values/social cohesion, and aesthetic benefits/cognitive development are least affected. This new approach of extending the ecosystem service concept through integration of spatial characteristics of ecosystem service provisional patches through landscape metrics is believed to give a more realistic appraisal of ecosystem services in urban areas.

  • 46.
    Hals, Carine
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Using Geographic Information Systems (GIS) to Analyze Possible Relations between School Choice and Segregation2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In 1992, the Swedish education system was reformed and by that, school choice was introduced. The intention of the reform was that competition between schools would improve the level of education; however, the results among Swedish pupils have deteriorated and the differences between schools have increased since the introduction. This has caused much debate on school choice, and especially school choice in relation to socioeconomic background and segregation.

    This study examines whether GIS can be used to detect possible relations between the school choices, socioeconomic backgrounds and residential areas of pupils in Uppsala Municipality in Sweden. Most of the previously conducted research do not use GIS as a tool, despite the spatial aspect of this issue. By mapping the data, any geographical patterns can easier be detected, patterns which can be hard to observe in other data presentation methods such as tables or graphs.

    The school choices and the commuting pattern among pupils applying for preschool or year six have been visualized in relation to the social index of their corresponding living areas. Four areas and four schools have been selected as samples in order to evaluate the issue from the perspective of both the pupils and the schools.

    The results show that GIS is an effective way of presenting complex data and a useful tool for detecting geographical clusters. The differences in choices made by pupils of dissimilar social background can be visually detected by comparing the maps to each other. The preschool pupils tend to apply for the nearest schools, while some of the pupils applying for year six are willing to travel further distances in order to get to a more popular school or an area less socially vulnerable than their residential area.  Furthermore, some deviant school choice patterns can easily be explained by examining the surrounding environment; the map can reveal for instance that the pupils had no other choice to make, that geographical obstructions such as water bodies or large streets act like separators or that the social index of a residential area perhaps do not match the affiliation felt by the inhabitants.

    Due to the complexity of school choice and segregation, a GIS might not be used alone for concluding on a relation between the two. However, it is a very useful tool for indicating occurrences of the phenomena and, most important, highlighting areas that are interesting for further investigation.

  • 47.
    Hilding, Fredrik
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Syk, Ella
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    User-centric Web-based System for Visualization of NIS-data for Layman Users2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Spatial data is playing a bigger role within many fields outside of Geographic Information Systems (GIS) and spatial analysis. With more and more users with varying levels of previous spatial analysis experience using this kind of data, there is a growing demand on how this information is best presented to the user. This user-centered design is an increasingly common theme in other adjacent fields, but is still in its infancy in the field of GIS. Currently there is no obvious generalized solution that provides the answer to how to present data, no matter if it is spatial or not. How to present data in a smart and comprehensive way is still an everyday challenge across many fields.

    The objective of this thesis is to create a prototype of a web based Network Information System (NIS) where the layman user is in the center of the entire design process. This includes both the actual visualizations, but also the choice of tools and the interface design. The prototype is designed around the role of the customer service representative in a utility company using a NIS. This type of layman user is the kind of user that today works in a system that is designed with neither their role nor their GIT experience or training in mind. From this prototype, the efficacy of different visualization techniques on layman users is evaluated, producing more general guidelines for user-centered development directed at layman users.

    The first step of this user-centered design process is to understand the user. By interviewing users of the system, their current work flows and opinions of their current system are better understood. From this, information about which tools they need, which current features work well and which need revising is gathered. Based on this, a mock-up is created which is then transformed into a prototype. Finally, the prototype is evaluated by the target audience with comments on a presentation as well as a larger survey.

    The results show that in general the prototype is well-received with regards to existing functionality and how it is presented through the interface design. The implemented visualizations are well understood by most of the expert users, but are less successful with the layman users in the survey. Especially with regards to the icon choices and other point representations, there is a discrepancy between the intended visualization and the perception of the survey takers, which may partly be due to the lack of context presented.

    An appreciated fact is that the functionality implemented in the prototype is tailored to the requirements put forth by the users. User-centric design processes depend heavily on the developer's understanding of the user and their needs. This is as true for functionality as for visualizations, where familiarity and associations can be both beneficial and detrimental, depending on how well understood they are. Using icons to represent objects is very efficient, as long as the context and the meaning of the icons themselves are well defined and conveyed.

    Finally, it is imperative to not throw too much information at the user. Whether in the shape of too many tools and options, or by displaying too much on the map, the same clutter-problem occurs. When presenting a situation or a scenario, the core message cannot be obfuscated by unnecessary features, functions or choices.

  • 48.
    Holm, Noah
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Möjligheter och utmaningar med öppna geodata2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Open geodata is today (2016) a highly debated topic and the interest for the matter is increasing, especially for the public sector. In the parliament, politicians have started to work for open geodata, where the parliament recently decided about several motions on the matter. Recently, there have also been assignments from the government about studying open geodata impacts.

    Sweden is behind the other Nordic countries and several other countries have evolved further towards open geodata as well. Today there is a lot of work on open geodata questions and the Swedish mapping, cadastral and land registration authority, Lantmäteriet, has started to open some of its data, and is aiming towards opening more.

    This Bachelor of Science thesis has been conducted at KTH Royal Institute of Technology, in cooperation with Agima Management AB. The study aims towards describing the opportunities that open geodata brings, and the challenges that an organization faces when opening data. These opportunities and challenges are summarized through a literature review of different opinions, mostly from the public sector, and personal interviews with persons in the geodata field.

    The results show that the foremost opportunities with open geodata is in developing business and innovation as well as efficiency improvements in the public sector which leads to economic gains. The challenges a public organization faces when trying to open geodata is mainly financial. The financial issues come from the current model where fees from users are financing the operations. In extension, there will also be challenges with sustaining a high quality of geodata, which will be a constant question for officials and politicians if geodata, for example is financed by taxes.

    The conclusion is that since the opportunities overcome the challenges, as many of the challenges are not direct drawbacks, but rather something that has to be solved in a different way than it is today, open geodata may become more normal in Sweden eventually. One of the reasons for Sweden’s relatively low speed in the area seems to be that public officials and politicians are at different levels in the matter today.

  • 49.
    Holm, Noah
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Plynning, Emil
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Spatio-temporal prediction of residential burglaries using convolutional LSTM neural networks2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The low amount solved residential burglary crimes calls for new and innovative methods in the prevention and investigation of the cases. There were 22 600 reported residential burglaries in Sweden 2017 but only four to five percent of these will ever be solved. There are many initiatives in both Sweden and abroad for decreasing the amount of occurring residential burglaries and one of the areas that are being tested is the use of prediction methods for more efficient preventive actions.

    This thesis is an investigation of a potential method of prediction by using neural networks to identify areas that have a higher risk of burglaries on a daily basis. The model use reported burglaries to learn patterns in both space and time. The rationale for the existence of patterns is based on near repeat theories in criminology which states that after a burglary both the burgled victim and an area around that victim has an increased risk of additional burglaries. The work has been conducted in cooperation with the Swedish Police authority.

    The machine learning is implemented with convolutional long short-term memory (LSTM) neural networks with max pooling in three dimensions that learn from ten years of residential burglary data (2007-2016) in a study area in Stockholm, Sweden. The model's accuracy is measured by performing predictions of burglaries during 2017 on a daily basis. It classifies cells in a 36x36 grid with 600 meter square grid cells as areas with elevated risk or not. By classifying 4% of all grid cells during the year as risk areas, 43% of all burglaries are correctly predicted. The performance of the model could potentially be improved by further configuration of the parameters of the neural network, along with a use of more data with factors that are correlated to burglaries, for instance weather. Consequently, further work in these areas could increase the accuracy.

    The conclusion is that neural networks or machine learning in general could be a powerful and innovative tool for the Swedish Police authority to predict and moreover prevent certain crime. This thesis serves as a first prototype of how such a system could be implemented and used.

  • 50.
    Hugosson, Alice
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    GIS som operativt arbetsverktyg inom Vattenfall Vattenkraft AB2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
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