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Auflistung Institut Geomatik nach Schlagwort "600 - Technik, Medizin, angewandte Wissenschaften"
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- PublikationA Change of theme. The role of generalization in thematic mapping(MDPI, 04.06.2020) Raposo, Paulo; Touya, Guillaume; Bereuter, Pia [in: ISPRS International Journal of Geo-Information]Cartographic generalization research has focused almost exclusively in recent years on topographic mapping, and has thereby gained an incorrect reputation for having to do only with reference or positional data. The generalization research community needs to broaden its scope to include thematic cartography and geovisualization. Generalization is not new to these areas of cartography, and has in fact always been involved in thematic geographic visualization, despite rarely being acknowledged. We illustrate this involvement with several examples of famous, public-audience thematic maps, noting the generalization procedures involved in drawing each, both across their basemap and thematic layers. We also consider, for each map example we note, which generalization operators were crucial to the formation of the map’s thematic message. The many incremental gains made by the cartographic generalization research community while treating reference data can be brought to bear on thematic cartography in the same way they were used implicitly on the well-known thematic maps we highlight here as examples.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationA change of theme. The role of generalization in thematic mapping(MDPI, 2020) Raposo, Paulo; Touya, Guillaume; Bereuter, Pia [in: ISPRS International Journal of Geo-Information]Cartographic generalization research has focused almost exclusively in recent years on topographic mapping, and has thereby gained an incorrect reputation for having to do only with reference or positional data. The generalization research community needs to broaden its scope to include thematic cartography and geovisualization. Generalization is not new to these areas of cartography, and has in fact always been involved in thematic geographic visualization, despite rarely being acknowledged. We illustrate this involvement with several examples of famous, public-audience thematic maps, noting the generalization procedures involved in drawing each, both across their basemap and thematic layers. We also consider, for each map example we note, which generalization operators were crucial to the formation of the map’s thematic message. The many incremental gains made by the cartographic generalization research community while treating reference data can be brought to bear on thematic cartography in the same way they were used implicitly on the well-known thematic maps we highlight here as examples.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationAccurate visual localization in outdoor and indoor environments exploiting 3D image spaces as spatial reference(International Society for Photogrammetry and Remote Sensing, 2018) Rettenmund, Daniel; Fehr, Markus; Cavegn, Stefan; Nebiker, Stephan [in: The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences]In this paper, we present a method for visual localization and pose estimation based on 3D image spaces. The method works in indoor and outdoor environments and does not require the presence of control points or markers. The method is evaluated with different sensors in an outdoor and an indoor test field. The results of our research show the viability of single image localization with absolute position accuracies at the decimetre level for outdoor environments and 5 cm or better for indoor environments. However, the evaluation also revealed a number of limitations of single image visual localization in real-world environments. Some of them could be addressed by an alternative AR-based localization approach, which we also present and compare in this paper. We then discuss the strengths and weaknesses of the two approaches and show possibilities for combining them to obtain accurate and robust visual localization in an absolute coordinate frame.04B - Beitrag Konferenzschrift
- PublikationAI-based 3D detection of parked vehicles on a mobile mapping platform using edge computing(2022) Meyer, Jonas; Blaser, Stefan; Nebiker, Stephan [in: The international archives of the photogrammetry, remote sensing and spatial information sciences]In this paper we present an edge-based hardware and software framework for the 3D detection and mapping of parked vehicles on a mobile mapping platform for the use case of on-street parking statistics. First, we investigate different point cloud-based 3D object detection methods on our extremely dense and noisy depth maps obtained from low-cost RGB-D sensors to find a suitable object detector and determine the optimal preparation of our data. We then retrain the chosen object detector to detect all types of vehicles, rather than standard cars only. Finally, we design and develop a software framework integrating the newly trained object detector. By repeating the parking statistics of our previous work (Nebiker et al., 2021), our software is tested regarding the detection accuracy. With our edge-based framework, we achieve a precision and recall of 100% and 98% respectively on any parking configuration and vehicle type, outperforming all other known work on on-street parking statistics. Furthermore, our software is evaluated in terms of processing speed and volume of generated data. While the processing speed reaches only 1.9 frames per second due to limited computing resources, the amount of data generated is just 0.25 KB per frame.04B - Beitrag Konferenzschrift
- PublikationBuilding aggregation to estimate the potential for shared energy generation with heat pumps(Copernicus Publications, 21.06.2023) Bereuter, Pia; Hall, Monika [in: Abstracts of the International Cartographic Association]04B - Beitrag Konferenzschrift
- PublikationCentimetre-accuracy in forests and urban canyons. Combining a high-performance image-based mobile mapping backpack with new georeferencing methods(Copernicus, 2020) Blaser, S.; Meyer, Jonas; Nebiker, Stephan; Fricker, L.; Weber, D. [in: ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences]Advances in digitalization technologies lead to rapid and massive changes in infrastructure management. New collaborative processes and workflows require detailed, accurate and up-to-date 3D geodata. Image-based web services with 3D measurement functionality, for example, transfer dangerous and costly inspection and measurement tasks from the field to the office workplace. In this contribution, we introduced an image-based backpack mobile mapping system and new georeferencing methods for capture previously inaccessible outdoor locations. We carried out large-scale performance investigations at two different test sites located in a city centre and in a forest area. We compared the performance of direct, SLAM-based and image-based georeferencing under demanding real-world conditions. Both test sites include areas with restricted GNSS reception, poor illumination, and uniform or ambiguous geometry, which create major challenges for reliable and accurate georeferencing. In our comparison of georeferencing methods, image-based georeferencing improved the median precision of coordinate measurement over direct georeferencing by a factor of 10–15 to 3 mm. Image-based georeferencing also showed a superior performance in terms of absolute accuracies with results in the range from 4.3 cm to 13.2 cm. Our investigations showed a great potential for complementing 3D image-based geospatial web-services of cities as well as for creating such web services for forest applications. In addition, such accurately georeferenced 3D imagery has an enormous potential for future visual localization and augmented reality applications.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationContent zooming and information exploration for web and mobile maps. Adaptation of real-time map generalisation to the information seeking strategies of web and mobile users(Lovoisier, 2013) Bereuter, Pia; Weibel, Robert; Burchardt, Dirk [in: Revue Internationale de Géomatique]In the context of the development of mobile map applications with capabilities for map generalisation and abstraction, we propose a methodology for content exploration that uses a technique that we term content zooming to change the degree of abstraction of map content independently of the map scale. Content zooming allows overriding the effects of ‘standard’ map generalisation, focusing on optimised content representation to aid the information seeking task of a mobile user. It is thus complementary to map generalisation. The paper defines content zooming operations and proposes technical solutions for each of these, illustrating them with examples from a research prototype.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationCriticality creates a functional platform for network transitions between internal and external processing modes in the human brain(Frontiers Research Foundation, 2021) Kim, Minkyung; Kim, Hyoungkyu; Huang, Zirui; Mashour, George A.; Jordan, Denis; Ilg, Rüdiger; Lee, UnCheol [in: Frontiers in Systems Neuroscience]Continuous switching between internal and external modes in the brain appears important for generating models of the self and the world. However, how the brain transitions between these two modes remains unknown. We propose that a large synchronization fluctuation of brain networks, emerging only near criticality (i.e., a balanced state between order and disorder), spontaneously creates temporal windows with distinct preferences for integrating the network’s internal information or for processing external stimuli. Using a computational model, electroencephalography (EEG) analysis, and functional magnetic resonance imaging (fMRI) analysis during alterations of consciousness in humans, we report that synchronized and incoherent networks, respectively, bias toward internal and external information with specific network configurations. In the brain network model and EEG-based network, the network preferences are the most prominent at criticality and in conscious states associated with the bandwidth 4−12 Hz, with alternating functional network configurations. However, these network configurations are selectively disrupted in different states of consciousness such as general anesthesia, psychedelic states, minimally conscious states, and unresponsive wakefulness syndrome. The network preference for internal information integration is only significant in conscious states and psychedelic states, but not in other unconscious states, suggesting the importance of internal information integration in maintaining consciousness. The fMRI co-activation pattern analysis shows that functional networks that are sensitive to external stimuli–such as default mode, dorsal attentional, and frontoparietal networks–are activated in incoherent states, while insensitive networks, such as global activation and deactivation networks, are dominated in highly synchronized states. We suggest that criticality produces a functional platform for the brain’s capability for continuous switching between two modes, which is crucial for the emergence of consciousness.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationCriticality creates a functional platform for network transitions between internal and external processing modes in the human brain(Frontiers Research Foundation, 2021) Kim, Minkyung; Kim, Hyoungkyu; Huang, Zirui; Mashour, George A.; Jordan, Denis; Ilg, Rüdiger; Lee, UnCheol [in: Frontiers in Systems Neuroscience]Continuous switching between internal and external modes in the brain appears important for generating models of the self and the world. However, how the brain transitions between these two modes remains unknown. We propose that a large synchronization fluctuation of brain networks, emerging only near criticality (i.e., a balanced state between order and disorder), spontaneously creates temporal windows with distinct preferences for integrating the network’s internal information or for processing external stimuli. Using a computational model, electroencephalography (EEG) analysis, and functional magnetic resonance imaging (fMRI) analysis during alterations of consciousness in humans, we report that synchronized and incoherent networks, respectively, bias toward internal and external information with specific network configurations. In the brain network model and EEG-based network, the network preferences are the most prominent at criticality and in conscious states associated with the bandwidth 4−12 Hz, with alternating functional network configurations. However, these network configurations are selectively disrupted in different states of consciousness such as general anesthesia, psychedelic states, minimally conscious states, and unresponsive wakefulness syndrome. The network preference for internal information integration is only significant in conscious states and psychedelic states, but not in other unconscious states, suggesting the importance of internal information integration in maintaining consciousness. The fMRI co-activation pattern analysis shows that functional networks that are sensitive to external stimuli–such as default mode, dorsal attentional, and frontoparietal networks–are activated in incoherent states, while insensitive networks, such as global activation and deactivation networks, are dominated in highly synchronized states. We suggest that criticality produces a functional platform for the brain’s capability for continuous switching between two modes, which is crucial for the emergence of consciousness.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationDevelopment of a portable high performance mobile mapping system using the robot operating system(Copernicus, 2018) Blaser, Stefan; Cavegn, Stefan; Nebiker, Stephan [in: ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences]The rapid progression in digitalization in the construction industry and in facility management creates an enormous demand for the efficient and accurate reality capturing of indoor spaces. Cloud-based services based on georeferenced metric 3D imagery are already extensively used for infrastructure management in outdoor environments. The goal of our research is to enable such services for indoor applications as well. For this purpose, we designed a portable mobile mapping research platform with a strong focus on acquiring accurate 3D imagery. Our system consists of a multi-head panorama camera in combination with two multi-profile LiDAR scanners and a MEMS-based industrial grade IMU for LiDAR-based online and offline SLAM. Our modular implementation based on the Robot Operating System enables rapid adaptations of the sensor configuration and the acquisition software. The developed workflow provides for completely GNSS-independent data acquisition and camera pose estimation using LiDAR-based SLAM. Furthermore, we apply a novel image-based georeferencing approach for further improving camera poses. First performance evaluations show an improvement from LiDAR-based SLAM to image-based georeferencing by an order of magnitude: from 10–13 cm to 1.3–1.8 cm in absolute 3D point accuracy and from 8–12 cm to sub-centimeter in relative 3D point accuracy.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationDigital twinning of the built environment. An interdisciplinary topic for innovation in didactics(Copernicus, 2020) Wahbeh, Wissam; Kunz, Dominique; Hofmann, Joachim; Bereuter, Pia [in: ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences]The concept of a Digital Twin (DT) takes an increasingly important role in the construction industry and related research fields. It is a concept associated with Industry 4.0; however, the scientific literature does not provide a unique and clear definition of this concept. This paper aims to analyse the definitions of the digital twin to clarify this concept in the related fields of architecture, engineering and construction (AEC). Moreover, this work proposes and employs the concept of a Digital Twin as an objective for a project-based learning approach in a didactical setting. As an interdisciplinary approach, this work demonstrates the potential impact on the traditional didactical frameworks in the educational domain of construction and its value as an opportunity to introduce interdisciplinary expertise to all students in these fields. This work presents a use case applying the concept at the School of Architecture, Civil Engineering and Geomatics of FHNW.04B - Beitrag Konferenzschrift
- PublikationDynamic patterns of global brain communication differentiate conscious from unconscious patients after severe brain injury(Frontiers Research Foundation, 2021) Golkowski, Daniel; Willnecker, Rebecca; Rösler, Jennifer; Ranft, Andreas; Schneider, Gerhard; Jordan, Denis; Ilg, Rüdiger [in: Frontiers in Systems Neuroscience]The neurophysiology of the subjective sensation of being conscious is elusive; therefore, it remains controversial how consciousness can be recognized in patients who are not responsive but seemingly awake. During general anesthesia, a model for the transition between consciousness and unconsciousness, specific covariance matrices between the activity of brain regions that we call patterns of global brain communication reliably disappear when people lose consciousness. This functional magnetic imaging study investigates how patterns of global brain communication relate to consciousness and unconsciousness in a heterogeneous sample during general anesthesia and after brain injury. First, we describe specific patterns of global brain communication during wakefulness that disappear during propofol and sevoflurane general anesthesia. Second, we search for these patterns in a cohort of unresponsive wakeful patients and unmatched healthy controls in order to evaluate their potential use in clinical practice. We found that patterns of global brain communication characterized by high covariance in sensory and motor areas or low overall covariance and their dynamic change were strictly associated with intact consciousness in this cohort. In addition, we show that the occurrence of these two patterns is significantly related to activity within the frontoparietal network of the brain, a network known to play a crucial role in conscious perception. We propose that this approach potentially recognizes consciousness in the clinical routine setting.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationEditorial(Taylor & Francis, 23.01.2020) Touya, Guillaume; Bereuter, Pia; Raposo, Paulo [in: International Journal of Cartography]01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationEvaluating the impact of visualization of risk upon emergency route-planning(Taylor & Francis, 2019) Cheong, Lisa; Kinkeldey, Christoph; Burfurd, Ingrid; Bleisch, Susanne; Duckham, Matt [in: International Journal of Geographical Information Science]This paper reports on a controlled experiment evaluating how different cartographic representations of risk affect participants’ performance on a complex spatial decision task: route planning. The specific experimental scenario used is oriented towards emergency route-planning during flood response. The experiment compared six common abstract and metaphorical graphical symbolizations of risk. The results indicate a pattern of less-preferred graphical symbolizations associated with slower responses and lower-risk route choices. One mechanism that might explain these observed relationships would be that more complex and effortful maps promote closer attention paid by participants and lower levels of risk taking. Such user considerations have important implications for the design of maps and mapping interfaces for emergency planning and response. The data also highlights the importance of the ‘right decision, wrong outcome problem’ inherent in decision-making under uncertainty: in individual instances, more risky decisions do not always lead to worse outcomes.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationExploratory bivariate and multivariate geovisualizations of a social vulnerability index(North American Cartographic Information Society, 2020) Strode, Georgianna; Mesev, Victor; Bleisch, Susanne; Ziewitz, Kathryn; Reed, Fennis; Morgan, John Derek [in: Cartographic Perspectives]In the United States, the Centers for Disease Control and Prevention (CDC) is the national agency that conducts and supports public health research and practice. Among the CDC’s many achievements is the development of a social vulnerability index (SVI) to aid planners and emergency responders when identifying vulnerable segments of the population, especially during natural hazard events. The index includes an overall social vulnerability ranking as well as four individual themes: socioeconomic, household composition & disability, ethnicity & language, and housing & transportation. This makes the SVI dataset multivariate, but it is typically viewed via maps that show one theme at a time. This paper explores a suite of cartographic techniques that can represent the SVI beyond the univariate view. Specifically, we recommend three techniques: (1) bivariate mapping to illustrate overall vulnerability and population density, (2) multivariate mapping using cartographic glyphs to disaggregate levels of the four vulnerability themes, and (3) visual analytics using Euler diagrams to depict overlap between the vulnerability themes. The CDC’s SVI, and by extension, vulnerability indices in other countries, can be viewed in a variety of cartographic forms that illustrate the location of vulnerable groups of society. Viewing data from various perspectives can facilitate the understanding and analysis of the growing amount and complexity of data.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationExploratory geovisualizations for supporting the qualitative analysis and synthesis of place-related emotion data(North American Cartographic Information Society, 2019) Bleisch, Susanne; Hollenstein, Daria [in: Cartographic Perspectives]Locations become places through personal significance and experience. While place data are not emotion data, per se, personal significance and experience are often emotional. In this paper, we explore the potential of using visual data exploration to support the qualitative analysis of place-related emotion data. To do so, we draw upon Creswell’s (2009) definition of place to define a generic data model that contains emotion data for a given location and its locale. For each data dimension in our model, we present symbolization options that can be combined to create a range of interactive visualizations, specifically supporting re-expression. We discuss the usefulness of example visualizations, created based on a data set from a pilot study on how elderly women experience their neighborhood. We find that the visualizations support four broad qualitative data analysis tasks: revising categorizations, making connections and relationships, aggregating for synthesis, and corroborating evidence by combining sense of place with locale information to support a holistic interpretation of place data. In conclusion, the paper contributes to the literature in three ways. It provides a generic data model and associated symbolization options, and uses examples to show how place-related emotion data can be visualized. Further, the example visualizations make explicit how re-expression, the combination of emotion data with locale information, and visualization of vagueness and linked data support the analysis of emotion data. Finally, we advocate for visualization-supported qualitative data analysis in interdisciplinary teams so that more suitable maps are used and so that cartographers can better understand and support qualitative data analysis.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationGaining overview with transient focus+context maps(Taylor & Francis, 2021) Hollenstein, Daria; Bleisch, Susanne [in: International Journal of Cartography]Gaining an overview of large spatial data sets presents a challenge common to various domains. 'Overviewing' spatial data involves viewing different areas of focus and context at different scales and requires access to detail from zoomed-out views. Standard pan and zoom interfaces provide limited support with this. Motivated by the application scenario of flood risk monitoring, we extend pan and zoom affordances with a combination of focus+context techniques and multiple maps to support 'overviewing' spatial data with a graph-like information structure. A combination of transient overlays to preview context-on-demand as well as detail-on-demand with the option to decouple additional maps enables fast navigation through the graph-like information space. User-created and -positioned, resizable multiple maps allow for simultaneous exploration of distant regions at flexible scales. The seamless integration of these concepts and the versatility of its components allow for continuously adaptable, user-defined layouts that support various analysis situations. We present a prototype implementation of this interaction model and illustrate its working in application to a hydrometric network, but we believe the model could be transferred to graph-like data in other domains.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationGeneralisation operators(Springer, 08.07.2014) Stanislawski, Lawrence V.; Buttenfield, Barbara P.; Bereuter, Pia; Savino, Sandro; Brewer, Cynthia A.; Burghardt, Dirk; Duchêne, Cécile; Mackaness, William [in: Abstracting geographic information in a data rich world. Methodologies and applications of map generalisation]This chapter summarises cartographic generalisation operators used to generalise geospatial data. It includes a review of recent approaches that have been tested or implemented to generalise networks, points, or groups. Emphasis is placed on recent advances that permit additional flexibility to tailor generalisation processing in particular geographic contexts, and to permit more advanced types of reasoning about spatial conflicts, preservation of specific feature characteristics, and local variations in geometry, content and enriched attribution. Rather than an exhaustive review of generalisation operators, the chapter devotes more attention to operators associated with network generalisation, which illustrates well the logic behind map generalisation developments. Three case studies demonstrate the application of operators to road thinning, to river network and braid pruning, and to hierarchical point elimination. The chapter closes with some summary comments and future directions.04A - Beitrag Sammelband
- PublikationImage-based orientation determination of mobile sensor platforms(International Society of Photogrammetry and Remote Sensing, 2021) Hasler, Oliver; Nebiker, Stephan [in: The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences]Abstract. Estimating the pose of a mobile robotic platform is a challenging task, especially when the pose needs to be estimated in a global or local reference frame and when the estimation has to be performed while the platform is moving. While the position of a platform can be measured directly via modern tachymetry or with the help of a global positioning service GNSS, the absolute platform orientation is harder to derive. Most often, only the relative orientation is estimated with the help of a sensor mounted on the robotic platform such as an IMU, with one or multiple cameras, with a laser scanner or with a combination of any of those. Then, a sensor fusion of the relative orientation and the absolute position is performed. In this work, an additional approach is presented: first, an image-based relative pose estimation with frames from a panoramic camera using a state-of-the-art visual odometry implementation is performed. Secondly, the position of the platform in a reference system is estimated using motorized tachymetry. Lastly, the absolute orientation is calculated using a visual marker, which is placed in the space, where the robotic platform is moving. The marker can be detected in the camera frame and since the position of this marker is known in the reference system, the absolute pose can be estimated. To improve the absolute pose estimation, a sensor fusion is conducted. Results with a Lego model train as a mobile platform show, that the trajectory of the absolute pose calculated independently with four different markers have a deviation < 0.66 degrees 50% of the time and that the average difference is < 1.17 degrees. The implementation is based on the popular Robotic Operating System ROS.04B - Beitrag Konferenzschrift
- PublikationInvestigating roundabout properties and bicycle accident occurrence at Swiss roundabouts: A logistic regression approach(MDPI, 2019) Hollenstein, Daria; Hess, Martin; Jordan, Denis; Bleisch, Susanne [in: ISPRS International Journal of Geo-Information]The positive effects of active mobility on mental and physical health as well as on air quality are widely acknowledged. Increasing the share of active travel is therefore an aim in many countries. Providing bicycle-safe infrastructure is one way to promote cycling. Roundabouts are a common traffic infrastructure and are supposed to facilitate safe and smooth traffic flow. However, data on road traffic accidents indicate an over-proportional involvement of cyclists in accidents at roundabouts. In the present study, the influence of roundabout geometry and traffic flow on bicycle accident occurrence was investigated using a logistic regression approach on twelve parameters of N = 294 mostly small- and mini-sized single-lane roundabouts in the Canton of Berne, Switzerland. Average weekday motorized traffic was identified as a major factor in explaining bicycle accident occurrence at roundabouts. Further, the radius of the central island, the location of the roundabout (in town vs. out of town) and the number of legs were significantly related to bicycle accident occurrence. While these results are in general agreement with findings from similar studies, the findings regarding the central island’s radius and the number of legs underpin the need for roundabout type-specific studies: Some parameters may not prove relevant in intermediate- to large-sized roundabouts, but become critical in small or mini roundabouts, which are common in Switzerland and numerous in the present sample.01A - Beitrag in wissenschaftlicher Zeitschrift