Publikationen


Suche nach „[Hofmann] [Peter]“ hat 48 Publikationen gefunden
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    NachhaltigElektrotechnik und MedientechnikTC Freyung

    Zeitschriftenartikel

    Q. Chaudhry, J. Lewis, A. Dudkiewicz, Boxall, A. B. A., G. Allmaier, Peter Hofmann, K. Tiede, A. Lehner, K. Molhave

    Development of a sample preparation approach to measure the size of nanoparticle aggregates by electron microscopy

    [Available online 29 November 2018]

    Particuology

    2018

    DOI: 10.1016/j.partic.2018.05.007

    Abstract anzeigen

    Electron microscopy (EM) is widely used for nanoparticle (NP) sizing. Following an initial assessment of two sample preparation protocols described in the current literature as “unperturbed”, we found that neither could accurately measure the size of NPs featuring a broad size distribution, e.g., aggregates. Because many real-world NP samples consist of aggregates, this finding was of considerable concern. The data showed that the protocols introduced errors into the measurement by either inducing agglomeration artefacts or providing a skewed size distribution towards small particles (skewing artefact). The focus of this work was to develop and apply a mathematical refinement to correct the skewing artefact. This refinement provided a much improved agreement between EM and a reference methodology, when applied to the measurement of synthetic amorphous silica NPs. Further investigation, highlighted the influence of NP chemistry on the refinement. This study emphasised the urgent need for greater and more detailed consideration regarding the sample preparation of NP aggregates to routinely achieve accurate measurements by EM. This study also provided a novel refinement solution applicable to the size characterisation of silica and citrate-coated gold NPs featuring broad size distributions. With further research, this approach could be extended to other NP types

    DigitalTC Freyung

    Beitrag (Sammelband oder Tagungsband)

    Peter Hofmann

    A Fuzzy Belief-Desire-Intention Model for Agent-Based Image Analysis (Chapter 14)

    Modern Fuzzy Control Systems and Its Applications

    2017

    DigitalTC Freyung

    Beitrag (Sammelband oder Tagungsband)

    Peter Hofmann, G. Bekkarnayeva

    Object-Based Change Detection of Informal Settlements

    Proceedings of the Joint Urban Remote Sensing Event (JURSE) [Dubai, UAE; March 6-8, 2017]

    2017

    DigitalTC Freyung

    Beitrag (Sammelband oder Tagungsband)

    M. Schmitzberger, I. Ozan, R. Graf, Peter Hofmann, S. Wegenkittl, M. Gruber, V. Andrejchenko, M. Belgiu, P. Lettmayer, T. Lampoltshammer

    Agent based image analysis (ABIA)-preliminary research results from an implemented framework

    Proceedings of GEOBIA 2016: Solutions and Synergies (Enschede, Netherlands; September 14-16, 2016)

    2016

    DigitalTC Freyung

    Beitrag (Sammelband oder Tagungsband)

    R. Feitosa, G.A.O.P. Costa, Peter Hofmann, P. Happ

    An object-based meta knowledge model for a distributed image interpretation system

    Proceedings of GEOBIA 2016: Solutions and Synergies (Enschede, Netherlands; September 14-16, 2016)

    2016

    DigitalTC Freyung

    Zeitschriftenartikel

    Peter Hofmann

    Defuzzification Strategies for Fuzzy Classifications of Remote Sensing Data

    Remote Sensing, vol. 8, no. 6, pp. 467-490

    2016

    DigitalTC Freyung

    Zeitschriftenartikel

    P. Atkinson, P. Schmidt, Peter Hofmann, C. Zimmer, R. Marschallinger, E. Trinka, J. Sellner, M. Mühlau

    A MS-lesion pattern discrimination plot based on geostatistics

    Brain and Behaviour, vol. 6, no. 3

    2016

    DigitalTC Freyung

    Beitrag (Sammelband oder Tagungsband)

    Peter Hofmann, C. Werthmann, H. Taubenböck

    Monitoring and Modelling of Informal Settlements – a Review on Recent Developments and Challenges

    Proceedings of the 2015 Joint Urban Remote Sensing Event (JURSE) [Lausanne, Switzerland; March 30 - April 1, 2015]

    2015

    ISBN: 9781479966523

    DigitalTC Freyung

    Zeitschriftenartikel

    R. Graf, Peter Hofmann, S. Wegenkittl, T. Blaschke, V. Andrejchenko, M. Belgiu, P. Lettmayer, T. Lampoltshammer

    Towards a framework for agent-based image analysis of remote-sensing data

    International Journal of Image and Data Fusion, vol. 6, no. 2, pp. 115-137

    2015

    DOI: 10.1080/19479832.2015.1015459

    Abstract anzeigen

    Object-based image analysis (OBIA) as a paradigm for analysing remotely sensed image data has in many cases led to spatially and thematically improved classification results in comparison to pixel-based approaches. Nevertheless, robust and transferable object-based solutions for automated image analysis capable of analysing sets of images or even large image archives without any human interaction are still rare. A major reason for this lack of robustness and transferability is the high complexity of image contents: Especially in very high resolution (VHR) remote-sensing data with varying imaging conditions or sensor characteristics, the variability of the objects’ properties in these varying images is hardly predictable. The work described in this article builds on so-called rule sets. While earlier work has demonstrated that OBIA rule sets bear a high potential of transferability, they need to be adapted manually, or classification results need to be adjusted manually in a post-processing step. In order to automate these adaptation and adjustment procedures, we investigate the coupling, extension and integration of OBIA with the agent-based paradigm, which is exhaustively investigated in software engineering. The aims of such integration are (a) autonomously adapting rule sets and (b) image objects that can adopt and adjust themselves according to different imaging conditions and sensor characteristics. This article focuses on self-adapting image objects and therefore introduces a framework for agent-based image analysis (ABIA).

    NachhaltigTC Freyung

    Zeitschriftenartikel

    Q. Chaudhry, A. Dudkiewicz, Boxall, A. B. A., K. Mølhave, Peter Hofmann, K. Tiede, Linsinger, T. P. J.

    Uncertainties of size measurements in electron microscopy characterization of nanomaterials in foods

    Food Chemistry, vol. 176, no. June 1, pp. 472-479

    2015

    DOI: 10.1016/j.foodchem.2014.12.071

    Abstract anzeigen

    Electron microscopy is a recognized standard tool for nanomaterial characterization, and recommended by the European Food Safety Authority for the size measurement of nanomaterials in food. Despite this, little data have been published assessing the reliability of the method, especially for size measurement of nanomaterials characterized by a broad size distribution and/or added to food matrices. This study is a thorough investigation of the measurement uncertainty when applying electron microscopy for size measurement of engineered nanomaterials in foods. Our results show that the number of measured particles was only a minor source of measurement uncertainty for nanomaterials in food, compared to the combined influence of sampling, sample preparation prior to imaging and the image analysis. The main conclusion is that to improve the measurement reliability, care should be taken to consider replications and matrix removal prior to sample preparation.

    TC Freyung

    Beitrag (Sammelband oder Tagungsband)

    Peter Hofmann, R. Marschallinger, C. Leitner

    3D-Modeling of deformed halite hopper crystals: Object based image analysis and support vector machine, a first evaluation

    Geophysical Research Abstracts (Proceedings of the EGU General Assembly 2014; Vienna, Austria; April 27 - May 02, 2014), vol. 16

    2014

    TC Freyung

    Beitrag (Sammelband oder Tagungsband)

    Peter Hofmann

    Defining robustness measures for OBIA framework: A case study for detecting informal settlements

    Global urban monitoring and assessment through earth observation, Boca Raton, Fla, vol. 10

    2014

    ISBN: 978-1466564497

    TC Freyung

    Zeitschriftenartikel

    G. Ladurner, J. Kraus, A. Kunz, Peter Hofmann, S. Golaszewski, R. Marschallinger, E. Trinka, M. Kronbichler, M. McCoy

    Usability and Potential of Geostatistics for Spatial Discrimination of Multiple Sclerosis Lesion Patterns

    Journal of Neuroimaging, vol. 24, no. 3, pp. 278-286

    2014

    TC Freyung

    Zeitschriftenartikel

    Peter Hofmann, R. Marschallinger, C. Leitner

    3D-modeling of deformed halite hopper crystals by Object Based Image Analysis

    Computers & Geosciences, vol. 73, no. December, pp. 61-70

    2014

    TC Freyung

    Zeitschriftenartikel

    Peter Hofmann, B. Hofer, M. Belgiu

    Coupling formalized knowledge bases with object-based image analysis

    Remote Sensing Letters, vol. 5, no. 6, pp. 530-538

    2014

    TC Freyung

    Zeitschriftenartikel

    D. Tiede, Peter Hofmann

    Image Segmentation Based on Hexagonal Sampling Grids

    South-Eastern European Journal of Earth Observation and Geomatics, vol. 3, no. 2S, pp. 173-178

    2014

    TC Freyung

    Zeitschriftenartikel

    R. Graf, Peter Hofmann, S. Wegenkittl, T. Blaschke, V. Andrejchenko, M. Belgiu, P. Lettmayer, T. Lampoltshammer

    ABIA – A Conceptual Framework for Agent Based Image Analysis

    South-Eastern European Journal of Earth Observation and Geomatics, vol. 3, no. 2S, pp. 125-130

    2014

    TC Freyung

    Zeitschriftenartikel

    D. Tiede, R. Queiroz Feitosa, M. Kelly, G. Hay, S. Lang, F. van Coillie, Peter Hofmann, van der Werff, H., E. Addink, T. Blaschke, van der Meer, F.

    Geographic Object-Based Image Analysis – Towards a new paradigm

    ISPRS Journal of Photogrammetry & Remote Sensing, vol. 87, no. 1, pp. 180-191

    2014

    TC Freyung

    Beitrag (Sammelband oder Tagungsband)

    S. Golaszewski, J. Kraus, Peter Hofmann, R. Marschallinger, A. Kunz

    Some Brainwork: Geostatistics for Fingerprinting MS Lesion Patterns in Space and Time

    Abstracts from the Spatial Statistics 2013 Conference (Ohio State University, Columbus, OH, USA; June 4-7, 2013), vol. Vol. 9

    2013

    TC Freyung

    Zeitschriftenartikel

    M. Unterwurzacher, Peter Hofmann, F. Zobl, R. Marschallinger

    Marble provenance designation with Object Based Image Analysis: State-of-the-art rock fabric characterization from petrographic micrographs

    Austrian Journal of Earth Sciences, vol. 106/2, no. 2, pp. 40-49

    2013