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  • 51.
    Jiang, Bin
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Okabe, AtsuyukiSchool of Cultural and Creative Studies, Aoyama Gakuin University, Tokyo, Japan.
    Special Issue: Street Networks and Spatial Analysis2014Collection (editor) (Refereed)
  • 52.
    Jiang, Bin
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Sui, Daniel
    A new kind of beauty out of the underlying scaling of geographic space2014In: Professional Geographer, ISSN 0033-0124, E-ISSN 1467-9272, Vol. 66, no 4, p. 676-686Article in journal (Refereed)
    Abstract [en]

    Geographic space demonstrates scaling or hierarchy, implying that there are far more small things than large ones. The scaling pattern of geographic space, if visualized properly (i.e., based on the head/tail breaks classification), can evoke a sense of beauty. This is our central argument. This beauty is a new type of aesthetic at a deeper structural level and differs in essence from an intuitive sense of harmony, perceived in terms of color, shape, texture, and ratio. This new kind of beauty was initially defined and discovered by Christopher Alexander, and promoted in his master work The Nature of Order. To paraphrase Mandelbrot, this is beauty for the sake of science rather than for art's sake or for the sake of commerce. Throughout the article, we attempt to argue and illustrate that the scaling of geographic space possesses this new kind of beauty, which has a positive impact on human well-being. The article further draws on the previous work of Nikos Salingaros and Richard Taylor on the beauty in architecture and arts to support our argument.

  • 53.
    Jiang, Bin
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Yao, Xiaobai
    University of Georgia, Athens, GA, USA.
    Geospatial analysis and modeling of urban structure and dynamics: an overview2010In: The GeoJournal Library, 2010, Volume 99, Part 1 / [ed] Bin Jiang and Xiaobai Yao, Berlin: Springer , 2010, p. 3-11Chapter in book (Other academic)
  • 54.
    Jiang, Bin
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Yao, Xiaobai
    Geospatial Analysis and Modelling of Urban Structure and Dynamics2010Collection (editor) (Other academic)
    Abstract [en]

    The increasingly urbanized world has created various problems of environment, climate, consumption of resources, and public health, which are closely linked to the side-effects of urbanization such as sprawl, congestion, housing affordability and loss of open space. Fundamental to the urban problems are two separate yet related issues: urban structure and urban dynamics. The chapters collected in this book present an excellent profile of the current state of geospatial analysis and modelling, and demonstrate how these approaches can contribute to the study of various urban issues. The book addresses key themes including new ways of capturing data digitally at the individual level, the development of systems based around networks, the notion of linking hierarchy to networks to morphology as in complexity theory, and the development of new ways of integrating diverse urban processes through simulation paying careful attention to the basic econometric and statistical principles of spatial analysis.

  • 55.
    Jiang, Bin
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Yin, Junjun
    Ht-index for quantifying the fractal or scaling structure of geographic features2014In: Annals of the Association of American Geographers, ISSN 0004-5608, E-ISSN 1467-8306, Vol. 104, no 3, p. 530-541Article in journal (Refereed)
    Abstract [en]

    Although geographic features, such as mountains and coastlines, are fractal, some studies have claimed that the fractal property is not universal. This claim, which is dubious, is mainly attributed to the strict definition of fractal dimension as a measure or index for characterizing the complexity of fractals. In this article, we propose an alternative, ht-index, to quantify the fractal or scaling structure of geographic features. A geographic feature has ht-index (h) if the pattern of far more small things than large ones recurs (h - 1) times at different scales. The higher the ht-index, the more complex the geographic feature. We conduct three case studies to illustrate how the computed ht-indexes capture the complexity of different geographic features. We further discuss how ht-index is complementary to fractal dimension and elaborate on a dynamic view behind ht-index that enables better understanding of geographic forms and processes.

  • 56.
    Karlsson, Janne Margrethe
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    De tysta studenternas kunskaper: tankar kring icke-verbala studenter på betygsgrundande seminarier2012In: I mötet mellan vetenskap och lärande: 13 högskolepedagogiska utmaningar / [ed] Göran Fransson & Helena Hammarström, Gävle: Gävle University Press , 2012, p. 33-44Chapter in book (Other academic)
  • 57.
    Kordi, Maryam
    et al.
    National University of Ireland, National Centre for Geocomputation.
    Brandt, Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Effects of increasing fuzziness on analytic hierarchy process for spatial multicriteria decision analysis2012In: Computers, Environment and Urban Systems, ISSN 0198-9715, E-ISSN 1873-7587, Vol. 36, no 1, p. 43-53Article in journal (Refereed)
    Abstract [en]

    Multicriteria decision analysis (MCDA) involves techniques which relatively recently have received great increase in interest for their capabilities of solving spatial decision problems. One of the most frequently used techniques of MCDA is Analytic Hierarchy Process (AHP). In the AHP, decision-makers make pairwise comparisons between different criteria to obtain values of their relative importance. The AHP initially only dealt with crisp numbers or exact values in the pairwise comparisons, but later it has been modified and adapted to also consider fuzzy values. It is necessary to empirically validate the ability of the fuzzified AHP for solving spatial problems. Further, the effects of different levels of fuzzification on the method have to be studied. In the context of a hypothetical GIS-based decision-making problem of locating a dam in Costa Rica using real-world data, this paper illustrates and compares the effects of increasing levels of uncertainty exemplified through different levels of fuzzification of the AHP. Practical comparison of the methods in this work, in accordance with the theoretical research, revealed that by increasing the level of uncertainty or fuzziness in the fuzzy AHP, differences between results of the conventional and fuzzy AHPs become more significant. These differences in the results of the methods may affect the final decisions in decision-making processes. This study concludes that the AHP is sensitive to the level of fuzzification and decision-makers should be aware of this sensitivity while using the fuzzy AHP. Furthermore, the methodology described may serve as a guideline on how to perform a sensitivity analysis in spatial MCDA. Depending on the character of criteria weights, i.e. the degree of fuzzification, and its impact on the results of a selected decision rule (e.g. AHP), the results from a fuzzy analysis may be used to produce sensitivity estimates for crisp AHP MCDA methods.

  • 58.
    Lim, Nancy Joy
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Åhlén, Julia
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Geovisualisation of uncertainty in simulated flood maps2014In: Proceedings of the International Conferences on Interfaces and Human Computer Interaction 2014, Game and Entertainment Technologies 2014 and Computer Graphics, Visualization, Computer Vision and Image Processing 2014 - Part of the Multi Conference on Computer Science and Information Systems, MCCSIS 2014 / [ed] Katherine Blashki and Yingcai Xiao, IADIS Press , 2014, p. 206-214Conference paper (Refereed)
    Abstract [en]

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

  • 59.
    Liu, Xintao
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute. KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geoinformatik och Geodesi.
    The Principle of Scaling of Geographic Space and its Application in Urban Studies2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Geographic space is the large-scale and continuous space that encircles the earth and in which human activities occur. The study of geographic space has drawn attention in many different fields and has been applied in a variety of studies, including those on cognition, urban planning and navigation systems. A scaling property indicates that small objects are far more numerous than large ones, i.e., the size of objects is extremely diverse. The concept of scaling resembles a fractal in geometric terms and a power law distribution from the perspective of statistical physics, but it is different from both in terms of application. Combining the concepts of geographic space and scaling, this thesis proposes the concept of the scaling of geographic space, which refers to the phenomenon that small geographic objects or representations are far more numerous than large ones. From the perspectives of statistics and mathematics, the scaling of geographic space can be characterized by the fact that the sizes of geographic objects follow heavy-tailed distributions, i.e., the special non-linear relationships between variables and their probability.

    In this thesis, the heavy-tailed distributions refer to the power law, lognormal, exponential, power law with an exponential cutoff and stretched exponential. The first three are the basic distributions, and the last two are their degenerate versions. If the measurements of the geographic objects follow a heavy-tailed distribution, then their mean value can divide them into two groups: large ones (a low percentage) whose values lie above the mean value and small ones (a high percentage) whose values lie below. This regularity is termed as the head/tail division rule. That is, a two-tier hierarchical structure can be obtained naturally. The scaling property of geographic space and the head/tail division rule are verified at city and country levels from the perspectives of axial lines and blocks, respectively.

    In the study of geographic space, the most important concept is geographic representation, which represents or partitions a large-scale geographic space into numerous small pieces, e.g., vector and raster data in conventional spatial analysis. In a different context, each geographic representation possesses different geographic implications and a rich partial knowledge of space. The emergence of geographic information science (GIScience) and volunteered geographic information (VGI) greatly enable the generation of new types of geographic representations. In addition to the old axial lines, this thesis generated several types of representations of geographic space: (a) blocks that were decomposed from road segments, each of which forms a minimum cycle such as city and field blocks (b) natural streets that were generated from street center lines using the Gestalt principle of good continuity; (c) new axial lines that were defined as the least number of individual straight line segments mutually intersected along natural streets; (d) the fewest-turn map direction (route) that possesses the hierarchical structure and indicates the scaling of geographic space; (e) spatio-temporal clusters of the stop points in the trajectories of large-scale floating car data.

    Based on the generated geographic representations, this thesis further applies the scaling property and the head/tail division rule to these representations for urban studies. First, all of the above geographic representations demonstrate the scaling property, which indicates the scaling of geographic space. Furthermore, the head/tail division rule performs well in obtaining the hierarchical structures of geographic objects. In a sense, the scaling property reveals the hierarchical structures of geographic objects. According to the above analysis and findings, several urban studies are performed as follows: (1) generate new axial lines based on natural streets for a better understanding of urban morphologies; (2) compute the fewest-turn and shortest map direction; (3) identify urban sprawl patches based on the statistics of blocks and natural cities; (4) categorize spatio-temporal clusters of long stop points into hotspots and traffic jams; and (5) perform an across-country comparison of hierarchical spatial structures.

    The overall contribution of this thesis is first to propose the principle of scaling of geographic space as well as the head/tail division rule, which provide a new and quantitative perspective to efficiently reduce the high degree of complexity and effectively solve the issues in urban studies. Several successful applications prove that the scaling of geographic space and the head/tail division rule are inspiring and can in fact be applied as a universal law, in particular, to urban studies and other fields. The data sets that were generated via an intensive geo-computation process are as large as hundreds of gigabytes and will be of great value to further data mining studies.

  • 60.
    Liu, Xintao
    et al.
    KTH.
    Jiang, Bin
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    A novel approach to the identification of urban sprawl patches based on the scaling of geographic space2011In: International journal of Geomatics and Geosciences, ISSN 0976-4380, Vol. 2, no 2, p. 415-429Article in journal (Refereed)
    Abstract [en]

    This paper introduces a novel approach to identifying urban sprawl patches based on the statistics of blocks and natural cities under the principle of scaling of geographic space. Blocks are the minimum cycles decomposed from a road network and the important geographic elements in the process of urbanization. Scaling of geographic space refers to the phenomenon that small geographic objects are far more numerous than large ones. In this study, the measurements of block area, morphology and structure are found to demonstrate scaling property and follow heavy tailed distributions. Because of this, the mean values of these measurements can clearly divide all blocks into a two-level hierarchical structure, of which each hierarchy represents different geographical implications. For instance, small blocks imply the urban area while large ones imply rural area. Based on these findings, an improved method is proposed to aggregate the small blocks into natural cities in Texas. We further identify the abnormal blocks inside the natural city of Dallas, Texas as sprawling blocks, which constitute what we call urban sprawl patches. Multiple levels of urban sprawl are classified by performing the above process iteratively. This approach provides a quantitative and natural way to assess urban sprawl in the context of the urban environment.

  • 61.
    Liu, Xintao
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Jiang, Bin
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Defining and generating axial lines from street center lines for better understanding of urban morphologies2012In: International Journal of Geographical Information Science, ISSN 1365-8816, E-ISSN 1365-8824, Vol. 26, no 8, p. 1521-1532Article in journal (Refereed)
    Abstract [en]

    Axial lines are defined as the longest visibility lines for representing individual linear spaces in urban environments. The least set of axial lines that cover the free space of an urban environment or the space between buildings constitute what is often called an axial map. This is a fundamental tool in space syntax, a theory developed by Bill Hillier and his colleagues for characterizing the underlying urban morphologies. For a long time, generating axial lines with the help of some graphic software has been a tedious manual process that is criticized for being time consuming, subjective, or even arbitrary. In this article, we redefine axial lines as the least set of individual straight line segments mutually intersected along natural streets that are generated from street center lines using the Gestalt principle of good continuity. Based on this new definition, we develop an automatic solution for generating the newly defined axial lines from street center lines. We apply this solution to six typical street networks (three from North America and three from Europe) and generate a new set of axial lines for analyzing the urban morphologies. Through a comparison study between the new axial lines and the conventional or old axial lines and between the new axial lines and natural streets, we demonstrate with empirical evidence that the newly defined axial lines are a better alternative for capturing the underlying urban structure.

  • 62.
    Liu, Zhina
    et al.
    Uppsala universitet, Institutionen för geovetenskaper.
    Koyi, Hemin
    Uppsala universitet, Institutionen för geovetenskaper.
    Nilfouroushan, Faramarz
    Uppsala universitet, Institutionen för geovetenskaper.
    Swantesson, Jan
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för hälsa och miljö.
    Reshetyuk, Yuriy
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Internal deformation within an unstable granular slope: insights from physical modeling2012Conference paper (Other academic)
    Abstract [en]

    The collapses of granular materials frequently occur in nature in the form of, for example, rock avalanches, debrisavalanches and debris flow. In previous studies of collapses of a granular material, most of the focus has been onthe effect of initial geometry and mechanical properties of the granular materials, the run-out distance, and thetopography of final deposit. In this study, results of analogue models and scanned natural failed slopes are usedto outline the mode of failure of an unstable slope. Model results and field observations are used to argue that agranular mass moves downslope in a wavy pattern resulting in its intensive deformation.In the models, we mainly investigated the internal deformation of collapses of granular slopes in terms of theirinternal structures and the spatial and temporal distribution of the latter. Model results showed that a displacedmass of the granular slope has the following two features: (1) Initial collapse resulted in a series of normal faults,where hanging-wall blocks were slightly deformed, like the slump-shear structures in nature; (2) With furthercollapse, a set of secondary structures, such as deformed/folded fault surfaces, faulted folds, displaced inclinedfolds, and overturned folds formed near the slope surface. The occurrence of these structures reflects the failureprocess of the granular mass in space and time. In addition, our model results show that the nature of basal frictionhas a significant influence on the geometry and kinematics of these structures at the slope toe. Model results showalso that the mass does not glide downslope along only one surface, but includes several gliding surfaces each ofwhich take part of the sliding. These gliding surfaces become steeper deeper in the sliding mass. Some of thesefeatures observed in the models are also detected in the field. Scanned failed slope surfaces show a wavy patternsimilar to that in the models, reflecting the presence of normal faults at the head of the slope and folding at theslope toe.

  • 63.
    Liu, Zhina
    et al.
    Uppsala universitet, Berggrundsgeologi.
    Koyi, Hemin
    Uppsala universitet, Berggrundsgeologi.
    Swantesson, Jan
    Karlstad University.
    Nilfouroushan, Faramarz
    Uppsala universitet, Berggrundsgeologi.
    Reshetyuk, Yuriy
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Kinematics and 3-D internal deformation of granular slopes: analogue models and natural landslides2013In: Journal of Structural Geology, ISSN 0191-8141, E-ISSN 1873-1201, Vol. 53, p. 27-42Article in journal (Refereed)
    Abstract [en]

    This study uses results from a series of analogue models, and field observations, scanned data and sections of natural landslides to investigate the kinematics and internal deformation during the failure of an unstable slope. The models simulate collapse of granular slopes and focus on the spatial and temporal distribution of their internal structures. Using a series of systematically designed models, we have studied the effect of friction and deformability of the runout base on internal deformation within a granular slope. The results of these different models show that the collapse of granular slopes resulted in different-generation extensional faults at the back of the slope, and contractional structures (overturned folds, sheath folds and thrusts) at the toe of the slope. The failure surfaces and the volume of the failure mass changed both spatially and temporally. Younger failure surfaces formed in the back of the older ones by incorporating additional new material from the head of the slope. Our model results also show that the nature of the runout base has a significant influence on the runout distance, topography and internal deformation of a granular slope. Model results are compared with natural landslides where local profiles were dug in order to decipher the internal structures of the failure mass. The natural cases show similar structural distribution at the head and toe of the failure mass. As in model results, our field observations indicate the presence of at least two generations of failure surfaces where the older ones are steeper.

  • 64.
    Molina, Roderic
    et al.
    GISIG.
    Saio, Giorgio
    GISIG.
    Östman, Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Data Harmonisation in the HUMBOLDT Scenarios and the HUMBOLDT Training Framework2010In: INSPIRE 2010 Conference in Krakow, Poland, 2010, 2010Conference paper (Other academic)
  • 65.
    Moreira, J. M. M.
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management. University of Extremadura, Spain .
    Nex, F.
    3D Optical Metrology Unit, Bruno Kessler Foundation (FBK), Trento, Italy .
    Agugiaro, G.
    3D Optical Metrology Unit, Bruno Kessler Foundation (FBK), Trento, Italy .
    Remondino, F.
    3D Optical Metrology Unit, Bruno Kessler Foundation (FBK), Trento, Italy .
    Lim, Nancy Joy
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    From DSM to 3D building models: A quantitative evaluation2013In: International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives / [ed] Sorgel U., Heipke C., Jacobsen K., Rottensteiner F., Gottingen: Copernicus gesellschaft MBH , 2013, Vol. 40, no 1W1, p. 213-219Conference paper (Refereed)
    Abstract [en]

    The paper reviews the state-of-the-art in 3D city models and building block generation, with a description of the most common solutions and approaches. Then the digital reconstruction and comparison of LoD1 and LoD2 building models obtained with commercial packages and using different input data are presented. As input data, a DSM at 1m resolution derived from a GeoEye-1 stereo-pair, a DSM from an aerial block at 50 cm GSD and a LiDAR-based DSM at 1m resolution are used. The geometric buildings produced with each dataset are evaluated with respect to some ground-truth measurements but also compared between them. Problems such as the quality of the input DSM, the accuracy of the necessary vector datasets containing the building footprints, the flexibility of the approaches and the potentialities of each dataset will be discussed. As reconstruction of the building models is largely influenced by the quality of the building footprints, which may be out-of-date or slightly shifted with respect to the employed DSMs/DTMs, an in-house method is being developed to derive them starting from the produced DSMs.

  • 66.
    Mårtensson, Stig-Göran
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Reshetyuk, Yuriy
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Fotogrammetriskt uppsving med obemannade flygplan (UAV)2013In: SINUS, no 3, p. 14-16Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    På Högskolan i Gävle har under vårterminen 2013 fyra examensarbeten genomförts för att undersöka möjligheter och problem med användandet av obemannade flygfarkoster för fotogrammetriska ändamål. Studenterna har läst det treåriga lantmätarprogrammet med teknisk inriktning, som liksom alla högskoleprogram, avslutas med ett examensarbete. De här fyra grupperna har haft ett gemensamt intresse, nämligen UAS, och deras undersökningar refereras i artikeln nedan. Men först en kort beskrivning av UAS.

  • 67.
    Mårtensson, Stig-Göran
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Reshetyuk, Yuriy
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Jivall, Lotti
    Lantmäteriet,Geodesy Division.
    Measurement uncertainty in network RTK GNSS-based positioning of a terrestrial laser scanner2012In: Journal of Applied Geodesy, ISSN 1862-9024, Vol. 6, no 1, p. 25-32Article in journal (Refereed)
    Abstract [en]

    This paper reports on investigation of measurement uncertainty in positioning of a terrestrial laser scanner with network RTK (Real-Time Kinematic) service provided by SWEPOS®, Swedish national network of permanent reference stations for GNSS (Global Navigation Satellite System). To simulate measurements by a scanner, a rotating flat bar fixed to a prism base, attached to a tribrach, was used. The tests have been carried out with both a rotating GNSS antenna (placed at different distances from the centre of rotation – radii) and a stationary antenna, under different time intervals (1–5 min). The results show that it is possible to achieve a standard uncertainty of less than 10 mm in plane and 16 mm in height, independently of the observation time and radius. Hence, network RTK can be used with advantage for precise direct georeferencing of point clouds, not only for determination of the position of the scanner, but also its orientation.

  • 68.
    Nelson, Ross
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Map of rural regions of Canada and case study communities2013Other (Refereed)
    Abstract [en]

    Shows the variation of rurality between Canada's census divisions.

  • 69.
    Nelson, Ross
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Murray, Catherine
    Simon Fraser University, Canada.
    Duxbury, Nancy
    University of Coimbra, Coimbra, Portugal.
    Cultural and Creative Economy Strategies for Community Transformation: Four Approaches2013In: Social Transformation in Rural Canada: Community, Cultures, and Collective Action / [ed] John Parkins and Maureen Reed, Vancouver, BC: University of British Columbia Press, 2013, p. 368-386Chapter in book (Refereed)
  • 70.
    Novák, Pavel
    et al.
    University of West Bohemia, Plzeň, Czech Republic.
    Tenzer, Robert
    National School of Surveying, Division of Sciences, University of Otago, Dunedin, New Zealand.
    Eshagh, Mehdi
    Royal Institute of Technology, Stockholm, Sweden.
    Bagherbandi, Mohammad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Evaluation of gravitational gradients generated by Earth's crustal structures2013In: Computers & Geosciences, ISSN 0098-3004, E-ISSN 1873-7803, Vol. 51, p. 22-33Article in journal (Refereed)
    Abstract [en]

    Spectral formulas for the evaluation of gravitational gradients generated by upper Earth’s mass components are presented in the manuscript. The spectral approach allows for numerical evaluation of global gravitational gradient fields that can be used to constrain gravitational gradients either synthesised from global gravitational models or directly measured by the spaceborne gradiometer on board of the GOCE satellite mission. Gravitational gradients generated by static atmospheric, topographic and continental ice masses are evaluated numerically based on available global models of Earth’s topography, bathymetry and continental ice sheets. CRUST2.0 data are then applied for the numerical evaluation of gravitational gradients generated by mass density contrasts within soft and hard sediments, upper, middle and lower crust layers. Combined gravitational gradients are compared to disturbing gravitational gradients derived from a global gravitational model and an idealised Earth’s model represented by the geocentric homogeneous biaxial ellipsoid GRS80. The methodology could be used for improved modelling of the Earth’s inner structure.

  • 71.
    Olsson, Perola
    et al.
    Lunds Universitet.
    Rost, Helén
    Reshetyuk, Yuriy
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Laserskanning2011In: Geodetisk och fotogrammetrisk mätnings- och beräkningsteknik, Lantmäteriet , 2011, p. 181-204Chapter in book (Other academic)
  • 72.
    Omer, Itzhak
    et al.
    Tel Aviv Univ, Tel Aviv, Israel.
    Jiang, Bin
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Imageability and topological eccentricity of urban streets2010In: Geospatial Analysis and Modelling of Urban Structure and Dynamics / [ed] Bin Jiang and Xiaobai Yao, Dordrecht: Springer , 2010, p. 163-175Chapter in book (Refereed)
    Abstract [en]

    Previous studies of the influence of structural qualities of urban street network on the image of the city are based mainly on centrality and connectivity measures taken from graph and space syntax theories. The paper suggests application of the structural property of eccentricity for considering the structural distinctiveness or differentiation of a given street in the overall street network. Eccentricity suggested by Q-analysis and based on the perspective of multidimensional chains of connectivity. This structural property is applied to the case of the city of Tel Aviv by using a geographic database of the street network and observed data acquired from Tel Aviv residents' production of sketch maps. The study's findings provide preliminary evidence for the relevance of the structural property of eccentricity for understanding the relationships between street network and the image of the city.

  • 73.
    Paasch, Jesper M.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Standardization of Real Property Rights and Public Regulations: The Legal Cadastral Domain Model2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The objective of this thesis is to develop a conceptual model for classification of real property rights and public regulations. The model is called the Legal Cadastral Domain Model.

    The model is intended to be a terminological framework for cross-border exchange of cadastral information. Parties exchanging cadastral information via the model do not require detailed knowledge of the legal system in which the right or regulation is created.

    The model is based on the principle that real property rights and public regulations influence real property ownership by being either beneficial or encumbering for the real property owner.

    The theoretical departure of the research presented in this thesis is in comparative legal theory and terminology. Real property rights and public regulations are important parts of real property legislation as they describe and secure the use and other exploitation of land, water and air.

    The research is conducted through studies in real property legislation and associated literature. The model has been developed through case studies on real property rights in Portugal, Germany, Ireland, the Netherlands and Sweden and public regulations in Portugal and Sweden.

    The generated results show that it seems possible to describe real property rights and public regulations regardless of their legal origin, at least in Western legal systems.

    The thesis also includes a discussion of terminological aspects concerning definitions of three-dimensional (3D) real property.

    The thesis consists of a summary and 6 papers.

  • 74. Pasanen-Mortensen, Marianne
    et al.
    Pyykönen, Markku
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Elmhagen, Bodil
    Where lynx prevail, foxes will fail: limitation of a mesopredator in Eurasia2013In: Global Ecology and Biogeography, ISSN 1466-822X, E-ISSN 1466-8238, Vol. 22, no 7, p. 868-877Article in journal (Refereed)
    Abstract [en]

    Aim Climate change and loss of apex predators can affect ecosystem structure and function through modified limitation processes. We investigated, on a continental scale, whether mesopredator abundance is limited from the top down by large predators, as predicted by the mesopredator release hypothesis, or by bottom-up factors. The mesopredator in focus is the red fox Vulpes vulpes, a key predator in many ecosystems due to its strong effects on prey abundance. Location Europe and northern Asia. Methods Data on red fox density were compiled from published papers and reports. For each site, we collated presence-absence data on large carnivores (Lynx lynx, Canis lupus, Canisaureus) and remote sensing data for factors potentially related to bottom-up limitation (winter severity, summer temperature, human density, primary productivity, tree cover). The data were analysed through structural equation modelling. Results The presence of lynx had a direct negative effect on red foxes, suppressing fox abundance. Also winter severity had a negative effect on red fox abundance, and in Eurasia as a whole this effect was partially mediated through lynx. Within the lynx distribution range, winter severity was the only bottom-up factor significantly affecting red fox abundance. Outside the lynx distribution range, primary productivity, summer temperature and human density had a positive effect on red fox abundance. Main conclusions Our results show that apex predators can limit mesopredator abundance on a continental scale, thus supporting the mesopredator release hypothesis. Winter severity also affected red fox abundance, partially due to an interaction between lynx and winter conditions. On the continental scale a complex network of processes operates with varying effects depending on mediation processes. Our results imply that apex predators can have an important effect on ecosystem structure by limiting mesopredator abundance, and we suggest that apex predators may dampen increases in mesopredator abundance driven by global warming.

  • 75.
    Reshetyuk, Yuriy
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Direct Georeferencing with GPS in Terrestrial Laser Scanning2010In: Zeitschrift für Geodäsie, Geoinformation und Landmanagement, ISSN 1618-8950, Vol. 135, no 3, p. 151-159Article in journal (Refereed)
    Abstract [en]

    In this paper, a combined terrestrial laser scanning survey system is presented, where GPS can be used for direct georeferencing of the point clouds. The results of investigations of this system show that it is possible to achieve the coordinate accuracy of better than 1 cm in the point cloud, both in plane and height, at the object distance of up to about 70 m.

  • 76.
    Reshetyuk, Yuriy
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Mårtensson, Stig-Göran
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Terrestrial laser scanning for detection of landfill gas: a pilot study2014In: Journal of Applied Geodesy, ISSN 1862-9024, Vol. 8, no 1, p. 87-96Article in journal (Refereed)
    Abstract [en]

    Methane built up in landlls as a result of breaking down of organic materials can be a renewable energy source if it is taken advantage of. The aim of research presented in this paper is to detect landll gas (that contains methane) by means of terrestrial laser scanning. The hypothesis is that where no surface leakage has been reported, the landll gas will expand or migrate. Therefore, it is possible to detect it through repeated scanning of the same area and comparison of Digital Terrain Models (DTMs) generated from the point clouds. Only the most signicant movements, i.e. vertical, are of interest in this case. During September–November 2011, a small area at Forsbacka landll in the vicinity of Gävle was scanned 10 times. Epoch-to-epoch comparisons of the resulting DTMs have shown two signicant changes (–27 and +19 mm) in elevation of the surface, and it is not impossible that they are caused by migrating landll gas. The method tested in this study is deemed to be rigorous and accurate for detecting small-scale swell-shrink behaviour of the ground surface (in our case a landll surface). However, both data processing and interpretation of the results have been considerably complicated by presence of low vegetation (weeds) on the study site, which was di-cult to lter away completely from the data. Based on our pilot study, we recommend that a larger area and a longer period of time are chosen to give basis for more grounded conclusions about presence of landll gas.

     

  • 77.
    Sahlin, Eva A.U.
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Glasser, Neil F.
    Institute of Geography and Earth Sciences, Aberystwyth University, Wales.
    The Geomorphological Map of Wales and its use in Geoconservation Assessment (poster)2011Conference paper (Other academic)
    Abstract [en]

    A geomorphological map is probably the most comprehensive way of illustrating the landform distribution, surface form, material, age, and the processes responsible for the landscape look. As such geomorphological maps are invaluable in the fields of geoconservation assessment, evaluation and management. It is therefore an oddity, as well as an inconvenience, that there is no systematic landform inventory or mapping of the geomorphology that is comparable to the surveys undertaken for geology or soils in the UK. For that purpose the project of “Developing a Geomorphological Map of Wales” was initiated by the Countryside Council for Wales (CCW) as part of a PhD project investigating the Quaternary glaciations of Wales.

    To develop a mapping methodology suitable for the Welsh landscape, three contrasting areas were selected to provide a wide range of geomorphological features. Aerial photography, satellite imagery, digital elevation models, and field investigations of landform/sediment associations, formed the foundation for landform interpretation, which were compiled in a GIS.

    Geomorphological maps of Cadair Idris, and the Central and North Cambrian Mountains were produced, scale 1:10 000 – 1:25 000. The maps form an extensive inventory of the geomorphological geodiversity, and were used for providing data to palaeoglaciological reconstructions and making geoconservation recommendations to the CCW. The recommended sites are of regional interest; their rareness, distinct morphology, interesting research and educational value makes them worthy of RIGS (Regional Important Geodiversity Sites) protection.

    A Geomorphological Map of Wales has the potential for wider practical, scientific and educational benefits, such as for governmental bodies, local authority planners, tourism, researchers, teachers, landowners and land managers. Without a full account of all the geomorphological components of a landscape, there can be no full understanding of the landscape history or the various landforming processes. Important geodiversity sites may be overlooked, badly managed or lost before their full potential are realised.

  • 78.
    Saio, Giorgio
    et al.
    GISIG.
    Marchese, Alessandra
    GISIG.
    Molina, Roderic
    GISIG.
    Östman, Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    A training framework to support the INSPIRE implementation process2010In: INSPIRE 2010 Conference in Krakow, Poland, 2010., 2010Conference paper (Other academic)
  • 79.
    Schmidinger, Helen
    et al.
    Uppsala universitet.
    Molin, Lena
    Uppsala universitet.
    Brandt, S. Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Excursions in school – past and present from Swedish and Anglo-Saxon perspectives2014In: European Journal of Geography, ISSN 1792-1341, Vol. 5, no 4, p. 87-101Article in journal (Refereed)
    Abstract [en]

    The purpose of this article is to present the results from a review of literature on geography excursions and field studies and to discuss their development over time, focusing on purpose, content, method, and execution. The scope was limited to Swedish and Anglo-Saxon literature, produced after the year 1900. The results show that excursions and field studies have since long been important methods in school teaching, not only in the subject geography. One of the purposes of using excursions and field studies in teaching is to facilitate the learning process of pupils and students. Several authors arguing that learning improved when the objects are studied in the real world. We can see that a continuous process of change has altered contents as well as conduction of the excursions. The previous instrumental orientation has moved toward more pupil-participating work methods. Today preparation is a keyword in most texts on excursions, and the perspectives have been broadened.

  • 80.
    Sjöberg, Lars
    et al.
    Royal Institute of Technology (KTH), Stockholm, Sweden .
    Bagherbandi, Mohammad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    A study on the Fennoscandian post-glacial rebound as observed by present-day uplift rates and gravity field model GOCO02S2013In: Acta Geodaetica et Geophysica Hungarica, ISSN 1217-8977, E-ISSN 1587-1037, Vol. 48, no 3, p. 317-331Article in journal (Refereed)
    Abstract [en]

    Repeated absolute gravity measurements in Fennoscandia have revealed that the on-going post-glacial rebound can be regarded as a pure viscous flow of mantle mass of density 3390 kg/m3 towards the central part of the region caused by a gravity/uplift rate of −0.167 μGal/mm. Our model estimates the rebound induced rates of changes of surface gravity and geoid height to have peaks of −1.9 μGal/yr and 1.6 mm/yr, respectively, the former being consistent with absolute gravity observations. The correlation coefficient of the spherical harmonic representations of the geoid height and uplift rate for the spectral windows between degrees 10 and 70 is estimated to −0.99±0.006, and the maximum remaining land uplift is estimated to the order of 80 m. Both the (almost) linear increase of relaxation time with degree and the linear relation between geoid height and uplift rate support a model with mass flow in the major part of the mantle and disqualify the model with a flow in a thin channel below the crust. The mean viscosity of the flow in the central uplift region is estimated to 4×1021 Pa s.

  • 81.
    Tenzer, Robert
    et al.
    Institute of Geodesy and Geophysics, School of Geodesy and Geomatics, Wuhan University, Wuhan, China.
    Bagherbandi, Mohammad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute. Division of Geodesy and Geoinformatics, Royal Institute of Technology (KTH), Stockholm, Sweden.
    Reference crust-mantle density contrast beneath Antarctica based  on the Vening Meinesz-Moritz isostatic inverse problem and CRUST2.0 seismic model2013In: Earth Science Research, ISSN 1927-0542, E-ISSN 1927-0550, Vol. 17, no 1, p. 7-12Article in journal (Refereed)
    Abstract [en]

    The crust-mantle (Moho) density contrast beneath Antarctica was estimated based on solving the Vening Meinesz-Moritz isostatic problem and using constraining information from a seismic global crustal model (CRUST2.0). The solution was found by applying a least-squares adjustment by elements method. Global geopotential model (GOCO02S), global topographic/bathymetric model (DTM2006.0), ice-thickness data for Antarctica (assembled by the BEDMAP project) and global crustal model (CRUST2.0) were used for computing isostatic gravity anomalies. Since CRUST2.0 data for crustal structures under Antarctica are not accurate (due to a lack of seismic data in this part of the world), Moho density contrast was determined relative to a reference homogenous crustal model having 2,670 kg/m3 constant density. Estimated values of Moho density contrast were between 160 and 682 kg/m3. The spatial distribution of Moho density contrast resembled major features of the Antarctic’s continental and surrounding oceanic tectonic plate configuration; maxima exceeding 500 kg/m3 were found throughout the central part of East Antarctica, with an extension beneath the Transantarctic mountain range. Moho density contrast in West Antarctica decreased to 400-500 kg/m3, except for local maxima up to ~ 550 kg/m3 in the central Antarctic Peninsula.

  • 82.
    Tenzer, Robert
    et al.
    National School of Surveying, University of Otago, Dunedin, New Zealand.
    Bagherbandi, Mohammad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Reformulation of the Vening-Meinesz Moritz Inverse Problem of Isostasy for Isostatic Gravity Disturbances2012In: International Journal of Geosciences, ISSN 2156-8359, E-ISSN 2156-8367, Vol. 3, no 5A, p. 918-929Article in journal (Refereed)
    Abstract [en]

    The isostatic gravity anomalies have been traditionally used to solve the inverse problems of isostasy. Since gravity measurements are nowadays carried out together with GPS positioning, the utilization of gravity disturbances in various regional gravimetric applications becomes possible. In global studies, the gravity disturbances can be computed using global geopotential models which are currently available to a relatively high accuracy and resolution. In this study we facilitate the definition of the isostatic gravity disturbances in the Vening-Meinesz Moritz inverse problem of isostasy for finding the Moho depths. We further utilize uniform mathematical formalism in the gravimetric forward modelling based on methods for a spherical harmonic analysis and synthesis of gravity field. We then apply both mathematical procedures to determine globally the Moho depths using the isostatic gravity disturbances. The results of gravimetric inversion are finally compared with the global crustal seismic model CRUST2.0; the RMS fit of the gravimetric Moho model with CRUST2.0 is 5.3 km. This is considerably better than the RMS fit of 7.0 km obtained after using the isostatic gravity anomalies.

  • 83.
    Tenzer, Robert
    et al.
    University of Otago.
    Bagherbandi, Mohammad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Cheinway, Hwang
    Chang, Emmy Tsui-Yu
    Moho Interface Modeling Beneath the Himalayas, Tibet and Central Siberia Using GOCO02S and DTM2006.02013In: Terrestrial, Atmospheric and Oceanic Science, ISSN 1017-0839, E-ISSN 2223-8964, Vol. 24, no 4, p. 581-590Article in journal (Refereed)
    Abstract [en]

    We apply a newly developed method to estimate the Moho depths and density contrast beneath the Himalayas, Tibet and Central Siberia. This method utilizes the combined least-squares approach based on solving the inverse problem of isostasy and using the constraining information from the seismic global crustal model (CRUST2.0). The gravimetric forward modeling is applied to compute the isostatic gravity anomalies using the global geopotential model (GOCO02S) and the global topographic/bathymetric model (DTM2006.0). The estimated Moho depths vary between 60 - 70 km beneath most of the Himalayas and Tibet and reach the maxima of ~79 km. The Moho depth under Central Siberia is typically 50 - 60 km. The Moho density contrast computed relative to the CRUST2.0 lower crustal densities has the maxima of ~300 kg m-3 under Central Tibet. It substantially decreases to 150 - 250 kg m-3 under Himalayas and north Tibet. The estimated Moho density contrast under central Siberia is within 100 - 200 kg m-3.

  • 84.
    Tenzer, Robert
    et al.
    University of Otago, National School of Surveying.
    Bagherbandi, Mohammad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Gladkikh, Vladislav
    University of Otago, National School of Surveying.
    Signature of the upper mantle density structure in the refined gravity data2012In: Computational Geosciences, ISSN 1420-0597, E-ISSN 1573-1499, Vol. 16, no 4, p. 975-986Article in journal (Refereed)
  • 85.
    Tenzer, Robert
    et al.
    University of Otago, National School of Surveying.
    Bagherbandi, Mohammad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Vajda, Peter
    Geophysical Institute of the Slovak Academy of Sciences.
    Depth-dependent density change within the continental upper mantle2012In: Slovak Academy of Sciences. Geophysical Institute. Contributions to Geophysics and Geodesy, ISSN 1338-0540, Vol. 42, no 1, p. 1-13Article in journal (Refereed)
  • 86.
    Tenzer, Robert
    et al.
    Wuhan Univ, Peoples R China.
    Bagherbandi, Mohammad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute. Royal Inst Technol KTH, Stockholm, Sweden.
    Vajda, Peter
    Slovak Acad Sci, Slovakia.
    Global model of the upper mantle lateral density structure based on combining seismic and isostatic models2013In: Geosciences Journal, ISSN 1598-7477, Vol. 17, no 1, p. 65-73Article in journal (Refereed)
  • 87.
    Åhlén, Julia
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Early Recognition of Smoke in Digital Video2010In: Advances in Communications, Computers, Systems, Circuits and Devices: European Conference of Systems, ECS'10, European Conference of Circuits Technology and Devices, ECCTD'10, European Conference of Communications, ECCOM'10, ECCS'10 / [ed] Mladenov, V; Psarris, K; Mastorakis, N; Caballero, A; Vachtsevanos, G, Athens: World Scientific and Engineering Academy and Society, 2010, p. 301-306Conference paper (Refereed)
    Abstract [en]

    This paper presents a method for direct smoke detection from video without enhancement pre-processing steps. Smoke is characterized by transparency, gray color and irregularities in motion, which are hard to describe with the basic image features. A method for robust smoke description using a color balancing algorithm and turbulence calculation is presented in this work. Background extraction is used as a first step in processing. All moving objects are candidates for smoke. We make use of Gray World algorithm and compare the results with the original video sequence in order to extract image features within some particular gray scale interval. As a last step we calculate shape complexity of turbulent phenomena and apply it to the incoming video stream. As a result we extract only smoke from the video. Features such shadows, illumination changes and people will not be mistaken for smoke by the algorithm. This method gives an early indication of smoke in the observed scene.

  • 88.
    Åhlén, Julia
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Indication of Methane Gas in IR-Imagery2011In: Proceedings of IADIS International Conference Computer Graphics, Visualization, Computer Vision and Image Processing 2011, 2011, p. 187-192Conference paper (Refereed)
    Abstract [en]

    There are human produced sources of methane gas, such as waste storages, that contribute to the global warmth and other negative effects. There is not much research on the correlation of such leakage and greenhouse effect. Methane gas is not visible for humans and thus impossible to detect using commercial cameras. Specially designed IR-camera can detect this gas and thus is used in this study. Using digital video taken over a waste disposal place we create a detection algorithm that is sensitive to the spectral and morphological characteristics of methane gas. Different kind of leakage can take place in waste disposal places. In case of small spot leakage there is a reason to assume failure in piping system and in case of widely spread leakage area we can state that it is caused by unsupervised storage of waste and this should be attended immediately. In digital video, background and target gas are distinguished using spectral and morphological classifiers, which are extracted from the analyzed IR-imagery. It is shown that indications of methane gas can be carried out efficiently using image processing techniques and the definition of turbulence of the image.

  • 89.
    Åhlén, Julia
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Knowledge Based Single Building Extraction and Recognition2014In: Recent Advances in Computer Engineering, Communications and Information Technology / [ed] Josip Music, WSEAS Press , 2014, p. 29-35Conference paper (Refereed)
    Abstract [en]

    Building facade extraction is the primary step in the recognition process in outdoor scenes. It is also a challenging task since each building can be viewed from different angles or under different lighting conditions. In outdoor imagery, regions, such as sky, trees, pavement cause interference for a successful building facade recognition. In this paper we propose a knowledge based approach to automatically segment out the whole facade or major parts of the facade from outdoor scene. The found building regions are then subjected to recognition process. The system is composed of two modules: segmentation of building facades region module and facade recognition module. In the facade segmentation module, color processing and objects position coordinates are used. In the facade recognition module, Chamfer metrics are applied. In real time recognition scenario, the image with a building is first analyzed in order to extract the facade region, which is then compared to a database with feature descriptors in order to find a match. The results show that the recognition rate is dependent on a precision of building extraction part, which in turn, depends on a homogeneity of colors of facades.

  • 90.
    Åhlén, Julia
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Time-space visualisation of Amur river channel changes due to flooding disaster2014In: Proceedings of the International Multidisciplinary Scientific GeoConference SGEM, 2014, Vol. 1:2, p. 873-882Conference paper (Refereed)
    Abstract [en]

    The analysis of flooding levels is a highly complex temporal and spatial assessment task that involves estimation of distances between references in geographical space as well as estimations of instances along the time-line that coincide with  given spatial locations. This work has an aim to interactively explore changes of Amur River boundaries caused by the severe flooding in September 2013. In our analysis of river bank changes we use satellite imagery (Landsat 7) to extract parts belonging to Amur River. We use imagery from that covers time interval July 2003 until February 2014. Image data is pre-processed using low level image processing techniques prior to visualization. Pre-processing has a purpose to extract information about the boundaries of the river, and to transform it into a vectorized format, suitable as inputs subsequent visualization. We develop visualization tools to explore the spatial and temporal relationship in the change of river banks. In particular the visualization shall allow for exploring specific geographic locations and their proximity to the river/floods at arbitrary times. We propose a time space visualization that emanates from edge detection, morphological operations and boundary statistics on Landsat 2D imagery in order to extract the borders of Amur River. For the visualization we use the time-space-cube metaphor. It is based on a 3D rectilinear context, where the 2D geographical coordinate system is extended with a time-axis pointing along the 3rd Cartesian axis. Such visualization facilitates analysis of the channel shape of Amur River and thus enabling for a conclusion regarding the defined problem. As a result we demonstrate our time-space visualization for river Amur and using some amount of geographical point data as a reference we suggest an adequate method of interpolation or imputation that can be employed to estimate value at a given location and time.   

  • 91.
    Åhlén, Julia
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Liu, Fei
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Evaluation of the Automatic methods for Building Extraction2014In: International Journal Of Computers and Communications, ISSN 2074-1294, Vol. 8, p. 171-176Article in journal (Refereed)
    Abstract [en]

    Recognition of buildings is not a trivial task, yet highly demanded in many applications including augmented reality for mobile phones. Recognition rate can be increased significantly if building façade extraction will take place prior to the recognitionprocess. It is also a challenging task since eachbuilding can be viewed from different angles or under differentlighting conditions. Natural situation outdoor is when buildings are occluded by trees, street signs and other objects. This interferes for successful building façade recognition. In this paper we evaluate the knowledge based approach  to automatically segment out the whole buildingfaçade or major parts of thefaçade. This automatic building detection algorithm is then evaluated against other segmentation methods such as SIFT and vanishing point approach. This work contains two main steps: segmentation of building façades region using two different approaches and evaluation of the methods using database of reference features. Building recognition model (BRM) includes evaluation step that uses Chamfer metrics. BMR is then compared to vanishing points segmentation. In the evaluation mode, comparison of these two different segmentation methods is done using the data from ZuBuD.Reference matching is also done using Scale Invariant Feature Transform. Theresults show that the recognition rate is satisfactory for the BMR model and there is no need to extract the whole building façade for the successful recognition.

  • 92.
    Östman, Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Examples of training modules in Gävle, Berlin and Dublin2010Conference paper (Other academic)
  • 93.
    Östman, Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Introduction of the VESTA GIS project2010Conference paper (Other academic)
  • 94.
    Östman, Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Network for testing GI services2010In: Proceedings from Symposium GIS Ostrava 2010, 2010, p. 6 s.-Conference paper (Refereed)
  • 95.
    Östman, Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Verktyg för dataharmonisering baserade på öppen källkod2010In: Kartdagarna 2010 i Jönköping, 14-16 April, 2010Conference paper (Other academic)
  • 96.
    Östman, Anders
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Bjerkman, Jan
    Future Position X.
    Regional GI Cluster in Support to the SDI Development2010In: International Conference SDI 2010 – Skopje, September 15-17 2010, 2010, p. 209-216Conference paper (Refereed)
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