@article{PalmVietenSalberetal., author = {Palm, Christoph and Vieten, Andrea and Salber, Dagmar and Pietrzyk, Uwe}, title = {Evaluation of Registration Strategies for Multi-modality Images of Rat Brain Slices}, series = {Physics in Medicine and Biology}, volume = {54}, journal = {Physics in Medicine and Biology}, number = {10}, doi = {10.1088/0031-9155/54/10/021}, pages = {3269 -- 3289}, abstract = {In neuroscience, small-animal studies frequently involve dealing with series of images from multiple modalities such as histology and autoradiography. The consistent and bias-free restacking of multi-modality image series is obligatory as a starting point for subsequent non-rigid registration procedures and for quantitative comparisons with positron emission tomography (PET) and other in vivo data. Up to now, consistency between 2D slices without cross validation using an inherent 3D modality is frequently presumed to be close to the true morphology due to the smooth appearance of the contours of anatomical structures. However, in multi-modality stacks consistency is difficult to assess. In this work, consistency is defined in terms of smoothness of neighboring slices within a single modality and between different modalities. Registration bias denotes the distortion of the registered stack in comparison to the true 3D morphology and shape. Based on these metrics, different restacking strategies of multi-modality rat brain slices are experimentally evaluated. Experiments based on MRI-simulated and real dual-tracer autoradiograms reveal a clear bias of the restacked volume despite quantitatively high consistency and qualitatively smooth brain structures. However, different registration strategies yield different inter-consistency metrics. If no genuine 3D modality is available, the use of the so-called SOP (slice-order preferred) or MOSOP (modality-and-slice-order preferred) strategy is recommended.}, subject = {Histologie}, language = {en} } @inproceedings{EibenPalmPietrzyketal., author = {Eiben, Bj{\"o}rn and Palm, Christoph and Pietrzyk, Uwe and Davatzikos, Christos and Amunts, Katrin}, title = {Error Correction using Registration for Blockface Volume Reconstruction of Serial Histological Sections of the Human Brain}, series = {Bildverarbeitung f{\"u}r die Medizin 2010; Algorithmen - Systeme - Anwendungen ; Proceedings des Workshops vom 22. bis 25. M{\"a}rz 2009 in Heidelberg}, booktitle = {Bildverarbeitung f{\"u}r die Medizin 2010; Algorithmen - Systeme - Anwendungen ; Proceedings des Workshops vom 22. bis 25. M{\"a}rz 2009 in Heidelberg}, publisher = {Springer}, address = {Berlin}, pages = {301 -- 305}, abstract = {For accurate registration of histological sections blockface images are frequently used as three dimensional reference. However, due to the use of endocentric lenses the images suffer from perspective errors such as scaling and seemingly relative movement of planes which are located in different distances parallel to the imaging sensor. The suggested correction of those errors is based on the estimation of scaling factors derived from image registration of regions characterized by differing distances to the point of view in neighboring sections. The correction allows the generation of a consistent three dimensional blockface volume.}, subject = {Histologie}, language = {en} } @misc{BeyerWeigertPalmetal., author = {Beyer, Thomas and Weigert, Markus and Palm, Christoph and Quick, Harald H. and M{\"u}ller, Stefan P. and Pietrzyk, Uwe and Vogt, Florian and Martinez, M.J. and Bockisch, Andreas}, title = {Towards MR-based attenuation correction for whole-body PET/MR imaging}, series = {The Journal of Nuclear Medicine}, volume = {47}, journal = {The Journal of Nuclear Medicine}, number = {Suppl. 1}, pages = {384P}, subject = {Kernspintomografie}, language = {en} } @misc{GraesselAxerPalmetal., author = {Gr{\"a}ßel, David and Axer, Markus and Palm, Christoph and Dammers, J{\"u}rgen and Amunts, Katrin and Pietrzyk, Uwe and Zilles, Karl}, title = {Visualization of Fiber Tracts in the Postmortem Human Brain by Means of Polarized Light}, series = {NeuroImage}, volume = {47}, journal = {NeuroImage}, number = {Suppl. 1}, doi = {10.1016/S1053-8119(09)71415-6}, pages = {142}, subject = {Gehirn}, language = {en} } @misc{WeigertBeyerQuicketal., author = {Weigert, Markus and Beyer, Thomas and Quick, Harald H. and Pietrzyk, Uwe and Palm, Christoph and M{\"u}ller, Stefan P.}, title = {Generation of a MRI reference data set for the validation of automatic, non-rigid image co-registration algorithms}, series = {Nuklearmedizin}, volume = {46}, journal = {Nuklearmedizin}, number = {2}, pages = {A116}, subject = {Kernspintomografie}, language = {en} } @inproceedings{PietrzykBauerVietenetal., author = {Pietrzyk, Uwe and Bauer, Dagmar and Vieten, Andrea and Bauer, Andreas and Langen, Karl-Josef and Zilles, Karl and Palm, Christoph}, title = {Creating consistent 3D multi-modality data sets from autoradiographic and histological images of the rat brain}, series = {IEEE Nuclear Science Symposium Conference Record}, volume = {6}, booktitle = {IEEE Nuclear Science Symposium Conference Record}, doi = {10.1109/NSSMIC.2004.1466754}, pages = {4001 -- 4003}, abstract = {Volumetric representations of autoradiographic and histological images gain ever more interest as a base to interpret data obtained with /spl mu/-imaging devices like microPET. Beyond supporting spatial orientation within rat brains especially autoradiographic images may serve as a base to quantitatively evaluate the complex uptake patterns of microPET studies with receptor ligands or tumor tracers. They may also serve for the development of rat brain atlases or data models, which can be explored during further image analysis or simulation studies. In all cases a consistent spatial representation of the rat brain, i.e. its anatomy and the corresponding quantitative uptake pattern, is required. This includes both, a restacking of the individual two-dimensional images and the exact registration of the respective volumes. We propose strategies how these volumes can be created in a consistent way and trying to limit the requirements on the circumstances during data acquisition, i.e. being independent from other sources like video imaging of the block face prior to cutting or high resolution micro-X-ray CT or micro MRI.}, language = {en} } @article{BauerHamacherBroeeretal., author = {Bauer, Dagmar and Hamacher, Kurt and Br{\"o}er, Stefan and Pauleit, Dirk and Palm, Christoph and Zilles, Karl and Coenen, Heinz H. and Langen, Karl-Josef}, title = {Preferred stereoselective brain uptake of D-serine}, series = {Nuclear Medicine and Biology}, volume = {32}, journal = {Nuclear Medicine and Biology}, number = {8}, doi = {10.1016/j.nucmedbio.2005.07.004}, pages = {793 -- 797}, abstract = {Although it has long been presumed that d-amino acids are uncommon in mammalians, substantial amounts of free d-serine have been detected in the mammalian brain. d-Serine has been demonstrated to be an important modulator of glutamatergic neurotransmission and acts as an agonist at the strychnine-insensitive glycine site of N-methyl-d-aspartate receptors. The blood-to-brain transfer of d-serine is thought to be extremely low, and it is assumed that d-serine is generated by isomerization of l-serine in the brain. Stimulated by the observation of a preferred transport of the d-isomer of proline at the blood-brain barrier, we investigated the differential uptake of [3H]-d-serine and [3H]-l-serine in the rat brain 1 h after intravenous injection using quantitative autoradiography. Surprisingly, brain uptake of [3H]-d-serine was significantly higher than that of [3H]-l-serine, indicating a preferred transport of the d-enantiomer of serine at the blood-brain barrier. This finding indicates that exogenous d-serine may have a direct influence on glutamatergic neurotransmission and associated diseases.}, subject = {Aminos{\"a}uren}, language = {en} } @article{LehmannPalm, author = {Lehmann, Thomas M. and Palm, Christoph}, title = {Color Line Search for Illuminant Estimation in Real World Scenes}, series = {Journal of the Optical Society of America (JOSA) A}, volume = {18}, journal = {Journal of the Optical Society of America (JOSA) A}, number = {11}, doi = {10.1364/JOSAA.18.002679}, pages = {2679 -- 2691}, abstract = {The estimation of illuminant color is mandatory for many applications in the field of color image quantification. However, it is an unresolved problem if no additional heuristics or restrictive assumptions apply. Assuming uniformly colored and roundly shaped objects, Lee has presented a theory and a method for computing the scene-illuminant chromaticity from specular highlights [H. C. Lee, J. Opt. Soc. Am. A 3, 1694 (1986)]. However, Lee's method, called image path search, is less robust to noise and is limited in the handling of microtextured surfaces. We introduce a novel approach to estimate the color of a single illuminant for noisy and microtextured images, which frequently occur in real-world scenes. Using dichromatic regions of different colored surfaces, our approach, named color line search, reverses Lee's strategy of image path search. Reliable color lines are determined directly in the domain of the color diagrams by three steps. First, regions of interest are automatically detected around specular highlights, and local color diagrams are computed. Second, color lines are determined according to the dichromatic reflection model by Hough transform of the color diagrams. Third, a consistency check is applied by a corresponding path search in the image domain. Our method is evaluated on 40 natural images of fruit and vegetables. In comparison with those of Lee's method, accuracy and stability are substantially improved. In addition, the color line search approach can easily be extended to scenes of objects with macrotextured surfaces.}, language = {en} } @article{Palm, author = {Palm, Christoph}, title = {Color Texture Classification by Integrative Co-Occurrence Matrices}, series = {Pattern Recognition}, volume = {37}, journal = {Pattern Recognition}, number = {5}, doi = {10.1016/j.patcog.2003.09.010}, pages = {965 -- 976}, abstract = {Integrative Co-occurrence matrices are introduced as novel features for color texture classification. The extended Co-occurrence notation allows the comparison between integrative and parallel color texture concepts. The information profit of the new matrices is shown quantitatively using the Kolmogorov distance and by extensive classification experiments on two datasets. Applying them to the RGB and the LUV color space the combined color and intensity textures are studied and the existence of intensity independent pure color patterns is demonstrated. The results are compared with two baselines: gray-scale texture analysis and color histogram analysis. The novel features improve the classification results up to 20\% and 32\% for the first and second baseline, respectively.}, language = {en} } @inproceedings{PalmVietenBaueretal., author = {Palm, Christoph and Vieten, Andrea and Bauer, Dagmar and Pietrzyk, Uwe}, title = {Evaluierung von Registrierungsstrategien zur multimodalen 3D-Rekonstruktion von Rattenhirnschnitten}, series = {Bildverarbeitung f{\"u}r die Medizin 2006}, booktitle = {Bildverarbeitung f{\"u}r die Medizin 2006}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/3-540-32137-3_51}, pages = {251 -- 255}, abstract = {In dieser Arbeit werden drei Strategien zur 3D Stapelung von multimodalen Schnittbildern vorgestellt. Die Strategien werden experimentell anhand von Dualtracer-Autoradiographien evaluiert. Dazu werden neue Maße zur Beschreibung der Konsistenz innerhalb einer Modalit{\"a}t und der Konsistenz der Modalit{\"a}ten untereinander entwickelt, die auf bekannten Registrierungsmetriken basieren. Gerade bez{\"u}glich der Konsistenz der Modalit{\"a}ten untereinander zeigen zwei Strategien die besten Resultate: (1) abwechselnde multimodale Registrierung (2) monomodale Rekonstruktion einer Modalit{\"a}t und multimodale 2D Registrierung der zweiten Modalit{\"a}t.}, subject = {Registrierung }, language = {de} } @inproceedings{PietrzykPalmBeyer, author = {Pietrzyk, Uwe and Palm, Christoph and Beyer, Thomas}, title = {Fusion strategies in multi-modality imaging}, series = {Medical Physics, Vol 2. Proceedings of the jointly held Congresses: ICMP 2005, 14th International Conference of Medical Physics of the International Organization for Medical Physics (IOMP), the European Federation of Organizations in Medical Physics (EFOMP) and the German Society of Medical Physics (DGMP) ; BMT 2005, 39th Annual Congress of the German Society for Biomedical Engineering (DGBMT) within VDE ; 14th - 17th September 2005, Nuremberg, Germany}, booktitle = {Medical Physics, Vol 2. Proceedings of the jointly held Congresses: ICMP 2005, 14th International Conference of Medical Physics of the International Organization for Medical Physics (IOMP), the European Federation of Organizations in Medical Physics (EFOMP) and the German Society of Medical Physics (DGMP) ; BMT 2005, 39th Annual Congress of the German Society for Biomedical Engineering (DGBMT) within VDE ; 14th - 17th September 2005, Nuremberg, Germany}, pages = {1446 -- 1447}, subject = {Bildgebendes Verfahren}, language = {en} } @misc{WeigertPalmQuicketal., author = {Weigert, Markus and Palm, Christoph and Quick, Harald H. and M{\"u}ller, Stefan P. and Pietrzyk, Uwe and Beyer, Thomas}, title = {Template for MR-based attenuation correction for whole-body PET/MR imaging}, series = {Nuklearmedizin}, volume = {46}, journal = {Nuklearmedizin}, number = {2}, pages = {A115}, subject = {Kernspintomografie}, language = {en} } @misc{AxerAxerPalmetal., author = {Axer, Markus and Axer, Hubertus and Palm, Christoph and Gr{\"a}ßel, David and Zilles, Karl and Pietrzyk, Uwe}, title = {Visualization of Nerve Fibre Orientation in the Visual Cortex of the Human Brain by Means of Polarized Light}, series = {Biomedizinische Technik}, volume = {52}, journal = {Biomedizinische Technik}, number = {Suppl.}, pages = {1569048-041}, subject = {Sehrinde}, language = {en} } @inproceedings{PalmDehnhardtVietenetal., author = {Palm, Christoph and Dehnhardt, Markus and Vieten, Andrea and Pietrzyk, Uwe}, title = {3D rat brain tumor reconstruction}, series = {Biomedizinische Technik}, volume = {50}, booktitle = {Biomedizinische Technik}, number = {Suppl. 1, Part 1}, pages = {597 -- 598}, subject = {Dreidimensionale Rekonstruktion}, language = {en} } @misc{PalmCrumPietrzyketal., author = {Palm, Christoph and Crum, William R. and Pietrzyk, Uwe and Hawkes, David J.}, title = {Application of Fluid and Elastic Registration Methods to Histological Rat Brain Sections}, series = {Biomedizinische Technik}, volume = {52}, journal = {Biomedizinische Technik}, number = {Suppl.}, pages = {1569048-859}, subject = {Registrierung }, language = {en} } @inproceedings{PalmLehmannBrednoetal., author = {Palm, Christoph and Lehmann, Thomas M. and Bredno, J. and Neuschaefer-Rube, C. and Klajman, S. and Spitzer, Klaus}, title = {Automated Analysis of Stroboscopic Image Sequences by Vibration Profiles}, series = {Advances in Quantitative Laryngoscopy, Voice and Speech Research, Procs. 5th International Workshop}, booktitle = {Advances in Quantitative Laryngoscopy, Voice and Speech Research, Procs. 5th International Workshop}, abstract = {A method for automated segmentation of vocal cords in stroboscopic video sequences is presented. In contrast to earlier approaches, the inner and outer contours of the vocal cords are independently delineated. Automatic segmentation of the low contrasted images is carried out by connecting the shape constraint of a point distribution model to a multi-channel regionbased balloon model. This enables us to robustly compute a vibration profile that is used as a new diagnostic tool to visualize several vibration parameters in only one graphic. The vibration profiles are studied in two cases: one physiological vibration and one functional pathology.}, language = {en} } @inproceedings{PalmFischerLehmannetal., author = {Palm, Christoph and Fischer, B. and Lehmann, Thomas M. and Spitzer, Klaus}, title = {Hierarchische Wasserscheiden-Transformation zur Lippensegmentierung in Farbbildern}, series = {Bildverarbeitung f{\"u}r die Medizin 2000}, booktitle = {Bildverarbeitung f{\"u}r die Medizin 2000}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/978-3-642-59757-2_20}, pages = {106 -- 110}, abstract = {Zur L{\"o}sung komplexer Segmentierungsprobleme wird eine hierarchische und farbbasierte Wasserscheidentransformation vorgestellt. Geringe Modifikationen bez{\"u}glich Startpunktwahl und Flutungsprozess resultieren in signifikanten Verbesserungen der Segmentierung. Das Verfahren wurde zur Lippendetektion in Farbbildsequenzen eingesetzt, die zur quantitativen Beschreibung von Sprechbewegungsabl{\"a}ufen automatisch ausgewertet werden. Die Experimente mit 245 Bildern aus 6 Sequenzen zeigten eine Fehlerrate von 13\%.}, language = {de} } @inproceedings{PalmLehmannSpitzer, author = {Palm, Christoph and Lehmann, Thomas M. and Spitzer, Klaus}, title = {Color Texture Analysis of Moving Vocal Cords Using Approaches from Statistics and Signal Theory}, series = {Advances in Quantitative Laryngoscopy, Voice and Speech Research, Procs. 4th International Workshop, Friedrich Schiller University, Jena}, booktitle = {Advances in Quantitative Laryngoscopy, Voice and Speech Research, Procs. 4th International Workshop, Friedrich Schiller University, Jena}, pages = {49 -- 56}, abstract = {Textural features are applied for detection of morphological pathologies of vocal cords. Cooccurrence matrices as statistical features are presented as well as filter bank analysis by Gabor filters. Both methods are extended to handle color images. Their robustness against camera movement and vibration of vocal cords is evaluated. Classification results due to three in vivo sequences are in between 94.4 \% and 98.9\%. The classification errors decrease if color features are used instead of grayscale features for both statistical and Fourier features}, language = {en} } @article{NeuschaeferRubeLehmannPalmetal., author = {Neuschaefer-Rube, C. and Lehmann, Thomas M. and Palm, Christoph and Bredno, J. and Klajman, S. and Spitzer, Klaus}, title = {3D-Visualisierung glottaler Abduktionsbewegungen}, series = {Aktuelle phoniatrisch-p{\"a}daudiologische Aspekte}, volume = {2001/2002}, journal = {Aktuelle phoniatrisch-p{\"a}daudiologische Aspekte}, number = {9}, publisher = {Median}, isbn = {3-922766-76-5}, pages = {58 -- 61}, language = {de} } @inproceedings{FischerPalmLehmannetal., author = {Fischer, B. and Palm, Christoph and Lehmann, Thomas M. and Spitzer, Klaus}, title = {Selektion von Farbtexturmerkmalen zur Tumorklassifikation dermatoskopischer Fotografien}, series = {Bildverarbeitung f{\"u}r die Medizin 2002}, booktitle = {Bildverarbeitung f{\"u}r die Medizin 2002}, publisher = {Springer}, address = {Berlin}, pages = {238 -- 241}, language = {de} } @book{Palm, author = {Palm, Christoph}, title = {Integrative Auswertung von Farbe und Textur}, publisher = {Der Andere Verlag}, language = {de} } @article{PalmDehnhardtVietenetal., author = {Palm, Christoph and Dehnhardt, Markus and Vieten, Andrea and Pietrzyk, Uwe and Bauer, Andreas and Zilles, Karl}, title = {3D rat brain tumors}, series = {Naunyn-Schmiedebergs Archives of Pharmacology}, volume = {371}, journal = {Naunyn-Schmiedebergs Archives of Pharmacology}, number = {R103}, language = {en} } @inproceedings{PalmSchollLehmannetal., author = {Palm, Christoph and Scholl, Ingrid and Lehmann, Thomas M. and Spitzer, Klaus}, title = {Nutzung eines Farbkonstanz-Algorithmus zur Entfernung von Glanzlichtern in laryngoskopischen Bildern}, series = {Methoden der Medizinischen Informatik, Biometrie und Epidemiologie in der modernen Informationsgesellschaft}, booktitle = {Methoden der Medizinischen Informatik, Biometrie und Epidemiologie in der modernen Informationsgesellschaft}, editor = {Greiser, E. and Wischnewsky, M.}, publisher = {MMV Medien und Medizin}, address = {M{\"u}nchen}, isbn = {9783820813357}, pages = {300 -- 303}, abstract = {1 Einf{\"u}hrung Funktionelle und organische St{\"o}rungen im Larynx beeintr{\"a}chtigen die Ausdrucksf{\"a}higkeit des Menschen. Zur Diagnostik und Verlaufkontrolle werden die Stimmlippen im Larynx mit Hilfe der Video-Laryngoskopie aufgenommen. Zur optimalen Farbmessung wird dazu an das Lupenendoskop eine 3-Chip-CCD-Kamera angeschlossen, die eine unabh{\"a}ngige Aufnahme der drei Farbkan{\"a}le erlaubt. Die bisherige subjektive Befundung ist von der Erfahrung des Untersuchers abh{\"a}ngig und l{\"a}ßt nur eine grobe Klassifikation der Krankheitsbilder zu. Zur Objektivierung werden daher quantitative Parameter f{\"u}r Farbe, Textur und Schwingung entwickelt. Neben dem Einfluß der wechselnden Lichtquellenfarbe auf den Farbeindruck ist die Sekretauflage auf den Stimmlippen ein Problem bei der Farb-und Texturanalyse. Sie kann zu ausgedehnten Glanzlichtern f{\"u}hren und so weite Bereiche der Stimmlippen f{\"u}r die Farb-und Texturanalyse unbrauchbar machen. Dieser Beitrag stellt einen Farbkonstanz-Algorithmus vor, der unabh{\"a}ngig von der Lichtquelle quantitative Farbwerte des Gewebes liefert und die Glanzlichtdetektion und -elimination erm{\"o}glicht. 2 Methodik Ziel des Farbkonstanz-Algorithmus ist die Trennung von Lichtquellen-und Gewebefarbe. Unter Verwendung des dichromatischen Reflexionsmodells [1] kann die Oberfl{\"a}chenreflexion mit der Farbe der Lichtquelle und die K{\"o}rperreflexion mit der Gewebefarbe identifiziert werden. Der Farbeindruck entsteht aus der Linearkombination beider Farbkomponenten. Ihre Gewichtung ist von der Aufnahmegeometrie abh{\"a}ngig, insbesondere vom Winkel zwischen Oberfl{\"a}chennormalen und dem Positionsvektor der Lichtquelle. In einem zweistufigen Verfahren wird zun{\"a}chst die Lichtquellenfarbe gesch{\"a}tzt, dann die Gewebefarbe ermittelt. Hieraus k{\"o}nnen beide Farbanteile durch die Berechnung der Gewichtsfaktoren pixelweise getrennt werden.}, language = {de} } @inproceedings{PalmLehmannSpitzer, author = {Palm, Christoph and Lehmann, Thomas M. and Spitzer, Klaus}, title = {Bestimmung der Lichtquellenfarbe bei der Endoskopie mikrotexturierter Oberfl{\"a}chen des Kehlkopfes}, series = {5. Workshop Farbbildverarbeitung, Ilmenau, 1999}, booktitle = {5. Workshop Farbbildverarbeitung, Ilmenau, 1999}, pages = {3 -- 10}, abstract = {Zur Unterst{\"u}tzung der Diagnose von Stimmlippenerkrankungen werden innerhalb des Forschungsprojektes Quantitative Digitale Laryngoskopie objektive Parameter zur Beschreibung der Bewegung, der Farbe sowie der Form der Stimmlippen entwickelt und klinisch evaluiert. W{\"a}hrend die Bewegungsanalyse Aufschluß {\"u}ber funktionelle Stimmst{\"o}rungen gibt, beschreiben Parameter der Farb- und Formanalyse morphologische Ver{\"a}nderungen des Stimmlippengewebes. In diesem Beitrag werden die Methoden und bisherigen Ergebnisse zur Bewegungs- und Farbanalyse vorgestellt. Die Bewegungsanalyse wurde mit einem erweiterten Konturmodell (Snakes) durchgef{\"u}hrt. Aufgrund des modifizierten Konturmodells konnten die Konturen der Stimmlippen automatisch {\"u}ber die gesmate Bildsequenz zuverl{\"a}ssig detektiert werden. Die Vermssung der Konturen liefert neue quantitative Parameter zur Befundung von laryngoskopischen Stimmlippenaufnahmen. Um die Farbeigenschaften der Stimmlippen zu bestimmen, wurde ausgehend vom RGB-Bild die Objektfarbe unabh{\"a}ngig von der Farbe der Lichtquelle durch Verwendung von Clusterverfahren und der Viertelkreisanalyse berechnet. Mit dieser Farbanalyse konnte die Farbe der Lichtquelle ermittelt und das beleuchtungsunabh{\"a}ngige Farbbild berechnet werden. Die Quanitifizierung der R{\"o}tung der Stimmlippen ist z.B. ein entscheidendes Kriterium zur Diagnostik der akuten Laryngitis.}, language = {de} } @inproceedings{PalmKeysersLehmannetal., author = {Palm, Christoph and Keysers, Daniel and Lehmann, Thomas M. and Spitzer, Klaus}, title = {Gabor Filtering of Complex Hue/Saturation Images for Color Texture Classification}, series = {Proceedings of the 5th Joint Conference on Information Science (JCIS) 2, The Association for Intelligent Machinery, Atlantic City, NJ, 2000}, booktitle = {Proceedings of the 5th Joint Conference on Information Science (JCIS) 2, The Association for Intelligent Machinery, Atlantic City, NJ, 2000}, pages = {45 -- 49}, abstract = {Objective: Complex hue/saturation images as a new approach for color texture classification using Gabor filters are introduced and compared with common techniques. Method: The interpretation of hue and saturationas polar coordinates allows direct use of the HSV-colorspace for Fourier transform. This technique is applied for Gabor feature extraction of color textures. In contrast to other color features based on the RGB-colorspace [1] the combination of color bands is done previous to the filtering. Results: The performance of the new HS-featuresis compared with that of RGB based as well as grayscale Gabor features by evaluating the classifi-cation of 30 natural textures. The new HS-featuresshow same results like the best RGB features but allow a more compact representation. On the averagethe color features improve the results of grayscale features. Conclusion: The consideration of the color information enhances the classification of color texture. The choice of colorspace cannot be adjudged finally, but the introduced features suggest the use of the HSV-colorspace with less features than RGB.}, language = {en} } @article{PalmLehmann, author = {Palm, Christoph and Lehmann, Thomas M.}, title = {Classification of Color Textures by Gabor Filtering}, series = {Machine GRAPHICS \& VISION}, volume = {11}, journal = {Machine GRAPHICS \& VISION}, number = {2/3}, pages = {195 -- 219}, language = {en} } @inproceedings{PalmMetzlerMohametal., author = {Palm, Christoph and Metzler, V. and Moham, B. and Dieker, O. and Lehmann, Thomas M. and Spitzer, Klaus}, title = {Co-Occurrence Matrizen zur Texturklassifikation in Vektorbildern}, series = {Bildverarbeitung f{\"u}r die Medizin}, booktitle = {Bildverarbeitung f{\"u}r die Medizin}, editor = {Evers, H. and Glombitza, G. and Lehmann, Thomas M. and Meinzer, H.-P.}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/978-3-642-60125-5_69}, pages = {367 -- 371}, abstract = {Statistische Eigenschaften nat{\"u}rlicher Grauwerttexturen werden mit Co-Occurrence Matrizen, basierend auf der Grauwertstatistik zweiter Ordnung, modelliert. Die Matrix gibt dann die apriori Wahrscheinlichkeiten aller Grauwertpaare an. Da in der medizinischen Bildverarbeitung verst{\"a}rkt Multispektralbilder ausgewertet werden, wird das bekannte Konzept hier auf beliebige Vektorbilder erweitert. Dadurch kann bei der Texturklassifikation die zur Verf{\"u}gung stehende Information vollst{\"a}ndig genutzt werden. Insbesondere zur Detektion von Farbtexturen ist dieser Ansatz geeignet, da Wertepaare unterschiedlicher Spektralebenen ausgewertet werden k{\"o}nnen. Ebenso kann die Methode auch bei der Multiskalendekomposition von Intensit{\"a}tsbildern zur Verbesserung der Texturerkennung beitragen. Die in den Matrizen entstehenden Muster lassen dann {\"u}ber die Extraktion geeigneter Texturdeskriptoren R{\"u}ckschl{\"u}sse auf die Texturen des Bildes zu.}, language = {de} } @inproceedings{PalmPelkmannLehmannetal., author = {Palm, Christoph and Pelkmann, Annegret and Lehmann, Thomas M. and Spitzer, Klaus}, title = {Distortion Correction of Laryngoscopic Images}, series = {Advances in quantitative laryngoscopy, voice and speech research, Proceedings of the 3rd international workshop Aachen, RWTH}, booktitle = {Advances in quantitative laryngoscopy, voice and speech research, Proceedings of the 3rd international workshop Aachen, RWTH}, pages = {117 -- 125}, abstract = {Laryngoscopic images of the vocal tract are used for diagnostic purposes. Quantitative mea-surements like changes of the glottis size or the surface of the vocal cords during an image sequence can be helpful to describe the healing process or to compare the findings of diffe-rent patients. Typically the endoscopic images are circulary symmetric distorted (barrel di-stortion). Therefore measurements of geometric dimensions depend on the object´s position in the image. In this paper an algorithm is presented which allows the computation of the translational invariant "real" object size by correcting the image distortion without using additional calibration of the optical environment.}, language = {en} } @inproceedings{PalmNeuschaeferRubeLehmannetal., author = {Palm, Christoph and Neuschaefer-Rube, C. and Lehmann, Thomas M. and Spitzer, Klaus}, title = {Wissensbasierte Bewegungskompensation in aktiven Konturmodellen}, series = {Bildverarbeitung f{\"u}r die Medizin}, booktitle = {Bildverarbeitung f{\"u}r die Medizin}, editor = {Evers, H. and Glombitza, G. and Lehmann, Thomas M. and Meinzer, H.-P.}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/978-3-642-60125-5_2}, pages = {8 -- 12}, abstract = {Zur Analyse von Lippenbewegungsabl{\"a}ufen wird ein aktives Konturmodell eingesetzt. Probleme bereitet die hohe Sprechgeschwindigkeit, die in star ken Objektverschiebungen result iert und bislang nicht durch eine alleinige Konturanpassung kompensiert werden kann. In diesem Beitrag werden die klassischen aktiven Konturmodelle um eine Vorjustierung der Grobkonturen erweitert, die eine energiebasierte Konturanpassung erst m{\"o}glich macht. Die Sch{\"a}tzung der Verschiebung zur Vorjustierung basiert auf dem Gradientenbild und einem pr{\"a}dikatenlogisch formulierten Regelwerk, das Annahmen und Nebenbedingungen als Wissensbasis enth{\"a}lt. Mit Hilfe dieser Erweiterungen ist eine automatisierte Konturverfolgung der Lippen m{\"o}glich.}, language = {de} } @inproceedings{PalmSchollLehmannetal., author = {Palm, Christoph and Scholl, Ingrid and Lehmann, Thomas M. and Spitzer, Klaus}, title = {Quantitative Farbmessung in laryngoskopischen Bildern}, series = {Bildverarbeitung f{\"u}r die Medizin}, booktitle = {Bildverarbeitung f{\"u}r die Medizin}, editor = {Lehmann, Thomas M. and Metzler, V. and Spitzer, Klaus and Tolxdorff, Thomas}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/978-3-642-58775-7_81}, pages = {412 -- 416}, abstract = {Quantitative Farbmessungen sollen die Diagnostik laryngealer Erkrankungen unterst{\"u}tzen. Dabei wird der Farbeindruck nicht nur durch die Reflexionseigenschaften des Gewebes sondern auch durch die Farbe der verwendeten Lichtquelle beeinflußt. Der hier vorgestellte Farbkonstanz-Algorithmus basiert auf dem dichromatischen Reflexionsmodell und liefert eine pixelweise Trennung des Farbbildes in seine beiden Faxbanteile. Die K{\"o}rperfarbe entspricht dabei der gewebespezifischen Reflexion, die Oberf{\"a}chenfarbe der Strahlung der Lichtquelle.}, language = {de} } @inproceedings{PalmSchollLehmannetal., author = {Palm, Christoph and Scholl, Ingrid and Lehmann, Thomas M. and Spitzer, Klaus}, title = {Trennung von diffuser und spiegelnder Reflexion in Farbbildern des Larynx zur Untersuchung von Farb- und Formmerkmalen der Stimmlippen}, series = {Bildverarbeitung f{\"u}r die Medizin. Algorithmen, Systeme, Anwendungen. Proceedings des Aachener Workshops am 8. und 9. November 1996}, booktitle = {Bildverarbeitung f{\"u}r die Medizin. Algorithmen, Systeme, Anwendungen. Proceedings des Aachener Workshops am 8. und 9. November 1996}, editor = {Lehmann, Thomas M. and Scholl, Ingrid and Spitzer, Klaus}, publisher = {Verlag der Augustinus-Buchhandlung}, address = {Aachen}, pages = {229 -- 234}, abstract = {Zur diagnostischen Unterst{\"u}tzung bei der Befundung laryngealer Erkrankungen soll eine Farb- und Formanalyse der Stimmlippen durchgef{\"u}hrt werden. In diesem Beitrag wird ein Verfahren zur Trennung der spiegelnden und diffusen Reflexionsanteile in Farbbildern des Larynx vorgestellt. Die Farbe der diffusen Komponente entspricht dabei der beleuchtungsunabh{\"a}ngigen Objektfarbe, w{\"a}hrend deren Wichtungsfaktoren als Eingabe f{\"u}r Shape-from-Shading-Verfahren zur Oberfl{\"a}chenrekonstruktion dienen.}, subject = {Laryngoskopie}, language = {de} } @inproceedings{HassanIlgnerPalmetal., author = {Hassan, H. and Ilgner, Justus F. R. and Palm, Christoph and Lehmann, Thomas M. and Spitzer, Klaus and Westhofen, Martin}, title = {Objective Judgement of Endoscopic Laryngeal Images}, series = {Advances in Quantitative Laryngoscopy, Voice and Speech Research, Proceedings of the 3rd International Workshop, RWTH Aachen}, booktitle = {Advances in Quantitative Laryngoscopy, Voice and Speech Research, Proceedings of the 3rd International Workshop, RWTH Aachen}, editor = {Lehmann, Thomas M. and Spitzer, Klaus and Tolxdorff, Thomas}, pages = {135 -- 142}, abstract = {Video Documentation of endoscopic findings simplifies diagnostic counseling of the patient and aids pre-operative discussion among the medical team. Judgment of such images is still subjective and can not give a quantitative evaluation of the disease process regarding diagnosis or response to treatment. Modern treatment of early laryngeal cancer with laserablation requires intensive follow up and frequent direct laryngoscopy under general anesthesia with blind biopsies to detect any tumor residual or recurrence. Inflammatory conditions of the larynx are frequently confused with other causes of dysphonia. Mapping anddigital analysis of the documented image will suggest the tumor site and avoids undue blind biopsies under anesthesia. However, varying illumination results in different colors reflected from the same object. To achieve quantitative analysis, color constancy has to be assured. Inthis paper, the environment is presented which allow the objective judgment of larngoscopies.}, language = {en} } @inproceedings{SchollPalmSovakaretal., author = {Scholl, Ingrid and Palm, Christoph and Sovakar, Abhijit and Lehmann, Thomas M. and Spitzer, Klaus}, title = {Quantitative Analyse der Stimmlippen}, series = {5. Workshop Digitale Bildverarbeitung in der Medizin, Universit{\"a}t Freiburg, 10.-11. M{\"a}rz 1997}, booktitle = {5. Workshop Digitale Bildverarbeitung in der Medizin, Universit{\"a}t Freiburg, 10.-11. M{\"a}rz 1997}, editor = {Arnolds, B. and Mueller, H. and Saupe, D. and Tolxdorff, Thomas}, pages = {81 -- 86}, language = {de} } @misc{OPUS4-418, title = {Advances in Quantitative Laryngoscopy, Voice and Speech Research, Procs. 3rd International Workshop, RWTH Aachen}, editor = {Lehmann, Thomas M. and Palm, Christoph and Spitzer, Klaus and Tolxdorff, Thomas}, address = {Aachen}, language = {en} } @inproceedings{MetzlerAachPalmetal., author = {Metzler, V. and Aach, T. and Palm, Christoph and Lehmann, Thomas M.}, title = {Texture Classification of Graylevel Images by Multiscale Cross-Co-Occurrence Matrices}, series = {Proceedings 15th International Conference on Pattern Recognition (ICPR-2000)}, booktitle = {Proceedings 15th International Conference on Pattern Recognition (ICPR-2000)}, doi = {10.1109/ICPR.2000.906133}, pages = {549 -- 552}, abstract = {Local gray level dependencies of natural images can be modelled by means of co-occurrence matrices containing joint probabilities of gray-level pairs. Texture, however, is a resolution-dependent phenomenon and hence, classification depends on the chosen scale. Since there is no optimal scale for all textures we employ a multiscale approach that acquires textural features at several scales. Thus linear and nonlinear scale-spaces are analyzed by multiscale co-occurrence matrices that describe the statistical behavior of a texture in scale-space. Classification is then performed on the basis of texture features taken from the individual scale with the highest discriminatory power. By considering cross-scale occurrences of gray level pairs, the impact of filters on the feature is described and used for classification of natural textures. This novel method was found to improve classification rates of the common co-occurrence matrix approach on standard textures significantly.}, language = {en} } @inproceedings{SchwaegerlBuchmannWestfechtel, author = {Schw{\"a}gerl, Felix and Buchmann, Thomas and Westfechtel, Bernhard}, title = {Multi-variant model transformations - a problem statement}, series = {Proceedings of the 11th International Conference on Evaluation of Novel Software Approaches to Software Engineering}, booktitle = {Proceedings of the 11th International Conference on Evaluation of Novel Software Approaches to Software Engineering}, publisher = {SCITEPRESS}, isbn = {978-989-758-189-2}, issn = {2184-4895}, doi = {10.5220/0005878702030209}, pages = {203 -- 209}, abstract = {Model Transformations are a key element of Model-Driven Software Engineering. As soon as variability is involved, transformations become increasingly complicated. The lack of support for variability in model transformations impairs the acceptance of approaches to organized reuse such as software product lines. In this position paper, the general problem of multi-variant model transformations is formulated for MOF-based, XMI-serialized models. A simplistic case study is presented to specify the input and the expected output of such a transformation. Furthermore, requirements for tool support are defined, including a standardized representation of both multi-variant model instances and variability information, as well as an execution specification for multi-variant transformations. A literature review reveals that the problem is weakly identified and often solved using ad-hoc solutions; there exists no tool providing a general solution to the proposed problem statement. The observation s presented here may serve for the future development of standards and tools.}, language = {en} } @book{KellnerLienlandLukesch, author = {Kellner, Florian and Lienland, Bernhard and Lukesch, Maximilian}, title = {Produktionswirtschaft : Planung, Steuerung und Industrie 4.0}, edition = {2., aktualisierte und erweiterte Auflage}, publisher = {Springer Gabler}, address = {Heidelberg}, doi = {10.1007/978-3-662-61446-4}, pages = {XXI, 399}, abstract = {Dieses Buch gibt einen umfassenden {\"U}berblick {\"u}ber wichtige Bereiche der Produktionswirtschaft. Der Schwerpunkt liegt auf dem operativen Produktionsmanagement. Es zeigt den Einsatz der Produktionsfaktoren Mensch, Betriebsmittel und Material, erkl{\"a}rt die Bedeutung von Informationen f{\"u}r die betriebliche F{\"u}hrung und bietet anhand zahlreicher Beispiele einen breiten Einblick in die Planung und Steuerung industrieller Produktion. Ausf{\"u}hrlich werden neben produktionswirtschaftlichen Grundlagen der Ablauf und Inhalt von Planungs- und Steuerungsprozessen erl{\"a}utert. Auch das aktuelle Thema Industrie 4.0 sowie cyber-physische Systeme werden dargestellt. In der 2. Auflage wurden umfangreiche {\"U}berarbeitungen hinsichtlich Sprache und Aufbau vorgenommen sowie anschauliche Beispielaufgaben, neue Unternehmensbeispiele und hilfreiche Hintergrunderkl{\"a}rungen erg{\"a}nzt.}, language = {de} } @book{KellnerLienlandLukesch, author = {Kellner, Florian and Lienland, Bernhard and Lukesch, Maximilian}, title = {Produktionswirtschaft : Planung, Steuerung und Industrie 4.0}, edition = {3., aktualisierte und erweiterte Auflage}, publisher = {Springer Gabler}, address = {Berlin}, isbn = {978-3-662-65802-4}, doi = {10.1007/978-3-662-65803-1}, pages = {XXI, 399}, abstract = {Dieses Buch bietet eine einsteigerfreundliche Einf{\"u}hrung in die f{\"u}r industrielle Betriebe maßgebliche Aufgabe der Produktionswirtschaft. Im Zentrum steht dabei das operative Produktionsmanagement. Hierzu geh{\"o}ren die erfolgswirksame Bewirtschaftung der Produktionsfaktoren Mensch, Betriebsmittel und Material, der Einsatz von Information sowie die Planung und Steuerung der industriellen Produktion. Mithilfe zahlreicher Unternehmensbeispiele und {\"U}bungsaufgaben wird der Leser durch produktionswirtschaftliche Grundlagen sowie durch Ablauf und Inhalt zentraler Prozesse in der Industrie geleitet. Auch die aktuelle Diskussion um das Thema Industrie 4.0 und cyber-physische Produktionssysteme werden lesefreundlich und mit konkretem Anwendungsbezug pr{\"a}sentiert.}, language = {de} } @book{KellnerLienlandLukesch, author = {Kellner, Florian and Lienland, Bernhard and Lukesch, Maximilian}, title = {Produktionswirtschaft : Planung, Steuerung und Industrie 4.0}, publisher = {Springer}, address = {Berlin, Heidelberg}, isbn = {9783662543412}, doi = {10.1007/978-3-662-54341-2}, pages = {XVII, 331}, abstract = {Dieses Buch gibt einen umfassenden {\"U}berblick {\"u}ber wichtige Bereiche der Produktionswirtschaft. Der Schwerpunkt liegt auf dem operativen Produktionsmanagement. Es zeigt den Einsatz der Produktionsfaktoren Mensch, Betriebsmittel, Material und Information und bietet anhand zahlreicher Beispiele einen ausf{\"u}hrlichen Einblick in die Planung und Steuerung industrieller Produktion. Ausf{\"u}hrlich werden neben produktionswirtschaftlichen Grundlagen der Ablauf und Inhalt von Planungs- und Steuerungsprozessen erl{\"a}utert. Auch das aktuelle Thema Industrie 4.0 sowie cyber-physische Systeme werden dargestellt.}, language = {de} } @phdthesis{FlorianKellner, author = {Florian Kellner,}, title = {Distribution Network Analysis for Fast Moving Consumer Goods}, publisher = {University of Regensburg}, address = {Regensburg}, isbn = {https://epub.uni-regensburg.de/32823/}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:355-epub-328237}, abstract = {This dissertation summarizes three reserach contributions that have been published in academic journals. The reserach analyzes economic and environmental sensitivites of Fast Moving Consumer Goods distribution networks.}, language = {en} } @incollection{FlorianKellnerMaximilianLukesch, author = {Florian Kellner, and Maximilian Lukesch,}, title = {Logistik nachhaltig gestalten: Die Bestimmung von CO2-Emissionen im Straßeng{\"u}tertransport}, series = {Praxishandbuch Logistik: Erfolgreiche Logistik in Industrie, Handel und Dienstleistungsunternehmen}, booktitle = {Praxishandbuch Logistik: Erfolgreiche Logistik in Industrie, Handel und Dienstleistungsunternehmen}, editor = {Uwe-H. Pradel, and Wolfram S{\"u}ssenguth, and Jochem Piontek, and Armin F. Schwolgin,}, publisher = {Dt. Wirtschaftsdienst}, address = {K{\"o}ln}, isbn = {978-3-87156-340-9}, abstract = {Dieser Beitrag gibt eine pr{\"a}gnante Einf{\"u}hrung in die Bestimmung von CO2-Emissionen im Straßeng{\"u}tertransport.}, language = {de} } @misc{Kellner, author = {Kellner, Florian}, title = {Supplier portfolio optimization}, series = {Ipsera Conference, April 2017, Balatonf{\"u}red/Budapest}, journal = {Ipsera Conference, April 2017, Balatonf{\"u}red/Budapest}, language = {en} } @incollection{KellnerOttoLienland, author = {Kellner, Florian and Otto, Andreas and Lienland, Bernhard}, title = {Cost Assignment Paradox: Indirect Tooling Costs and Production Orders}, series = {Advances in Management Accounting}, volume = {23}, booktitle = {Advances in Management Accounting}, publisher = {Emerald}, doi = {10.1108/S1474-787120140000023007}, pages = {211 -- 251}, abstract = {Purpose Tooling is a common component of an industrial product's manufacture. Specific tooling is devised to serve the fabrication of a particular product, while generic tooling can be used in the manufacture of multiple products. In the latter case, companies are confronted with the problem of fairly allocating the indirect costs of the tooling. This article studies how to allocate costs of generic tooling to single production orders. Methodology Ten allocation methods (AMs) are described that are in principle suited to the distribution of generic tooling costs to production orders. Since the presented methods have for the most part been discussed in differing contexts, we apply them to a specified generic tooling problem for comparison. Evaluation of the various methods is based on 16 criteria. Reasoning is supported by a computational Monte Carlo simulation. Furthermore, we suggest using the Analytical Hierarchy Process (AHP) to elaborate one final proposition concerning the most preferable allocation scheme. Findings The article reports the single allocation rules' performances for different allocation scenarios. The described characteristics refer to fairness, efficiency, and simplicity as well as to empty-core performance. Using AHP analysis allows for the aggregation of the rules' criteria ratings. Thus, especially suitable allocation schemes for the problem at hand are identified. Practical implications An allocation is required for budgeting reasons and also for the definition of projects' bottom-up sales prices. Selecting the "right" AM is important, as a suboptimal AM can result in unfair allocation vectors, which will act as incentives to stop using the common resource, potentially leading to higher total costs. Originality/value of the article Research on the comparison of AMs is typically performed for certain purposes, such as enterprise networks, horizontal cooperative purchasing scenarios, or municipal service units. This article will augment the research evaluating AMs by introducing a novel set of evaluation criteria and by providing an in-depth comparison of AMs suited for the allocation of generic tooling costs.}, language = {en} } @misc{Kellner, author = {Kellner, Florian}, title = {Business Analytics Anwendungen in der Logistik}, series = {Werkstoffe in der Fertigung : das Portal f{\"u}r die Fertigungswelt von morgen}, journal = {Werkstoffe in der Fertigung : das Portal f{\"u}r die Fertigungswelt von morgen}, abstract = {Der Begriff Business Analytics (BA) beschreibt die datengetriebene Analyse von Gesch{\"a}ftsprozessen. Ziel ist es, mittels IT-Einsatz und unter Anwendung mathematischer und statistischer Verfahren vergangenheits- und zukunftsorientierte Einblicke in ein Unternehmen zu erhalten um, darauf aufbauend, m{\"o}glichst optimale Handlungsempfehlungen abzuleiten. Die folgenden Ausf{\"u}hrungen sind dazu gedacht, dem Leser anhand logistischer Fragestellungen ein grunds{\"a}tzliches Verst{\"a}ndnis f{\"u}r den Begriff „Business Analytics" zu vermitteln.}, language = {de} } @article{LukeschKellner, author = {Lukesch, Maximilian and Kellner, Florian}, title = {Green Controlling in Logistiknetzwerken}, series = {Controlling : Zeitschrift f{\"u}r erfolgsorientierte Unternehmenssteuerung}, volume = {28}, journal = {Controlling : Zeitschrift f{\"u}r erfolgsorientierte Unternehmenssteuerung}, number = {8-9}, publisher = {C.H. Beck}, doi = {10.15358/0935-0381-2016-8-9-526}, pages = {526 -- 529}, language = {en} } @misc{Kellner, author = {Kellner, Florian}, title = {Changes in the field of FMCG distribution logistics and their impacts on the cost optimal distribution network - A simulation based case study}, series = {15th European Logistics Association Doctorate Workshop // June 2010, Nantes-Saint Nazaire, France}, journal = {15th European Logistics Association Doctorate Workshop // June 2010, Nantes-Saint Nazaire, France}, language = {en} } @article{LienlandZengMayrocketal., author = {Lienland, Bernhard and Zeng, Li and Mayrock, Michael and Kellner, Florian}, title = {Operations Research im Controlling}, series = {Controlling : Zeitschrift f{\"u}r erfolgsorientierte Unternehmenssteuerung}, volume = {29}, journal = {Controlling : Zeitschrift f{\"u}r erfolgsorientierte Unternehmenssteuerung}, number = {2}, publisher = {C.H. Beck ; Vahlen}, doi = {10.15358/0935-0381-2017-2-55}, pages = {55 -- 57}, language = {de} } @misc{Kellner, author = {Kellner, Florian}, title = {Analyzing the greenhouse gas sensitivity of distribution networks}, series = {Global Cleaner Production and Sustainable Consumption Conference // November 2015, Sitges/Barcelona}, journal = {Global Cleaner Production and Sustainable Consumption Conference // November 2015, Sitges/Barcelona}, language = {en} } @misc{Kellner, author = {Kellner, Florian}, title = {GHG network analysis FMCG}, series = {Logistikmanagement, September 2013, Bremen}, journal = {Logistikmanagement, September 2013, Bremen}, language = {en} } @article{KellnerSchroeder, author = {Kellner, Florian and Schr{\"o}der, Nadine}, title = {Data Mining mit unsicheren Daten}, series = {HMD Praxis der Wirtschaftsinformatik}, volume = {55}, journal = {HMD Praxis der Wirtschaftsinformatik}, number = {3}, publisher = {Springer Natrure}, doi = {10.1365/s40702-018-0419-5}, pages = {601 -- 613}, abstract = {Im Zeitalter von Big Data werden immense Informationsbest{\"a}nde aus unterschiedlichen Quellen gesammelt. Die Daten sind h{\"a}ufig unvollst{\"a}ndig, unsicher und ungenau. Ein Beispiel hierf{\"u}r ist das OpenStreetMap Projekt, bei dem Nutzer auf der ganzen Welt einmal mehr und einmal weniger „sauber" bzw. vollst{\"a}ndig Daten beisteuern. In diesem Beitrag wird gezeigt, ob sich diese Daten eignen um ein betriebswirtschaftliches Problem zu l{\"o}sen. Ein konkretes Fallbeispiel verdeutlicht, wie gut Standortentscheidungen einer Fast Food Kette unter Anwendung fortgeschrittener datenanalytischer Verfahren, wie bspw. K{\"u}nstlicher Neuronaler Netze, Entscheidungsb{\"a}ume und Logit-Modelle, nachempfunden werden k{\"o}nnen. Als Grundlage dienen die Daten des OpenStreetMap Projekts. Im Konkreten geht es darum, potenzielle Filialstandorte hinsichtlich deren G{\"u}te mittels OpenStreetMap Daten zu klassifizieren und die prognostizierten Lokationen mit tats{\"a}chlichen Standortentscheidungen zu vergleichen. Dabei zeigt sich, dass die Daten des OpenStreetMap Projekts grunds{\"a}tzlich f{\"u}r die Prognose von Standorten geeignet sind. Allerdings ist die Wahl des datenanalytischen Verfahrens von Bedeutung. Im vorliegenden Fall konnte mit Hilfe der K{\"u}nstlichen Neuronalen Netze das beste Prognoseergebnis erzielt werden.}, language = {en} } @article{KellnerGoerkLienland, author = {Kellner, Florian and Goerk, Anna Christina and Lienland, Bernhard}, title = {Mit CO2-Kennzahlen die {\"O}kobilanz verbessern}, series = {Controlling \& Management Review}, volume = {61}, journal = {Controlling \& Management Review}, number = {9}, publisher = {Springer}, doi = {10.1007/s12176-017-0118-z}, pages = {58 -- 64}, abstract = {CO-Emissionen sind ein wichtiger Indikator f{\"u}r die Beurteilung der {\"o}kologischen Nachhaltigkeit von Unternehmen. In der Praxis sind sie jedoch schwierig zu bestimmen. Insbesondere f{\"u}r Logistik-und Transportaktivit{\"a}ten, auf die ein Großteil der Emissionen entf{\"a}llt, sind zuverl{\"a}ssige Methoden zur Ermittlung und Reduktion des Schadstoffausstoßes erforderlich.}, language = {de} } @article{KellnerOttoBusch, author = {Kellner, Florian and Otto, Andreas and Busch, Andreas}, title = {Understanding the robustness of optimal FMCG distribution networks}, series = {Logistics Research}, volume = {6}, journal = {Logistics Research}, number = {4}, publisher = {Springer}, address = {Berlin, Heidelberg}, doi = {10.1007/s12159-012-0097-6}, pages = {173 -- 185}, abstract = {Distribution network design is about recommending long-term network structures in an environment where logistic variables like transportation costs or retailer order sizes dynamically change over time. The challenge for management is to recommend an optimal network configuration that will allow for longer term optimal results despite of environmental turbulences. This paper studies the robustness of cost-optimized FMCG (fast-moving consumer goods) distribution networks. It aims at observing the impact of changing variables/conditions on optimized logistic structures in terms of the optimal number and geographical locations of existing distribution centers. Five variables have been identified as relevant to the network structure. A case study approach is applied to study the robustness of an existing, typical, and optimized FMCG network. First, distribution network data of a German manufacturer of FMCG are recorded and analyzed. A quantitative model is set up to reflect the actual cost structure. Second, a cost optimal network configuration is determined as a benchmark for further analysis. Third, the variables investigated are altered to represent changes, both isolated (ceteris paribus) and in combination (scenario analysis). Each one of the variables investigated proves to be fundamentally able to suggest a change of the optimal network structure. However, the scenario analysis indicates that the expected changes will by and large compensate each other, leaving the network in near optimal condition over an extended period of time.}, language = {en} } @article{ZengKellnerLienland, author = {Zeng, Li and Kellner, Florian and Lienland, Bernhard}, title = {Rucksackprobleme in der Praxis - schnelle Entscheidungen schwer gemacht}, series = {HMD Praxis der Wirtschaftsinformatik}, volume = {53}, journal = {HMD Praxis der Wirtschaftsinformatik}, publisher = {Springer}, address = {Wiesbaden}, doi = {10.1365/s40702-016-0207-z}, pages = {310 -- 322}, abstract = {Unternehmen sind h{\"a}ufig mit Situationen konfrontiert, in denen schnell Entscheidungen bez{\"u}glich der Auswahl mehrerer Handlungsalternativen gefunden werden m{\"u}ssen. Mathematische Verfahren k{\"o}nnen hierbei unterst{\"u}tzen, z. B. f{\"u}r die Ermittlung einer ersten Diskussionsbasis. Verf{\"u}gbare Softwarel{\"o}sungen errechnen zwar h{\"a}ufig optimale Ergebnisse, zeigen jedoch Schw{\"a}chen bei der praktischen Anwendbarkeit. So ist eine Einarbeitung in komplexe Optimierungssoftware f{\"u}r die teilweise sporadisch auftretenden Probleme in der Regel f{\"u}r Unternehmen nicht m{\"o}glich, unter anderem auch unter Anbetracht der teilweise hohen Kosten der Standardsoftware und dem ben{\"o}tigten hohen Einarbeitungsaufwand. Gerade Problemstellungen in Fachbereichen, die nicht auf mathematische Probleml{\"o}sung spezialisiert sind, m{\"u}nden daher regelm{\"a}ßig in Ineffizienzen. Basierend auf den in der Literatur diskutierten L{\"o}sungsans{\"a}tzen wurde ein praxisorientierter Ansatz zur Entscheidungsunterst{\"u}tzung f{\"u}r Rucksackprobleme bzw. 0-1 Probleme mithilfe von Genetischen Algorithmen (GA) entwickelt und technisch in Microsoft Excel® umgesetzt. Ein Praxistest bei einem chinesischen Textilunternehmen belegt erh{\"o}hte Effektivit{\"a}t und Effizienz. Die Software kann kostenfrei nach MIT Lizenz unter http://www.solvega.de/ heruntergeladen werden.}, language = {de} } @article{Kellner, author = {Kellner, Florian}, title = {Analyse logistischer Systeme mittels Online-Navigationsdiensten - Bessere Planung auf Grundlage besserer Daten}, series = {HMD Praxis der Wirtschaftsinformatik}, volume = {53}, journal = {HMD Praxis der Wirtschaftsinformatik}, number = {6}, publisher = {Springer}, address = {Wiesbaden}, doi = {10.1365/s40702-016-0245-6}, pages = {894 -- 905}, abstract = {Online-Navigationsdienste erm{\"o}glichen die Planung einer Reise von einem Start- zu einem Ziel-Ort. Die Berechnung von Reisedauer und Streckenl{\"a}nge erfolgt auf Grundlage eines detaillierten Straßennetzes und unter Ber{\"u}cksichtigung Orts- und Zeit-typischer Verkehrsaufkommen. Dieser Beitrag zeigt, inwiefern Online-Navigationsdienste die Planung und Analyse logistischer Systeme unterst{\"u}tzen k{\"o}nnen. Er thematisiert insbesondere die Qualit{\"a}t der zur Verf{\"u}gung gestellten Verkehrsinfrastrukturdaten und hebt die komparativen Vorteile des Einsatzes von Online-Navigationsdiensten im Vergleich zu ‚herk{\"o}mmlichen' Verkehrsinformationsquellen hervor. Ein Anwendungsfall, bei dem die durch Transportaktivit{\"a}ten verursachten CO2-Emissionen eines G{\"u}ternahverkehrsnetzes untersucht werden, verdeutlicht die gewonnenen Erkenntnisse.}, language = {en} } @book{LukeschKellner, author = {Lukesch, Maximilian and Kellner, Florian}, title = {{\"U}bungsbuch Produktionswirtschaft}, publisher = {Springer Gabler}, address = {Berlin}, isbn = {9783662576892}, doi = {10.1007/978-3-662-57689-2}, pages = {XVI, 217}, abstract = {Dieses Buch bietet mehr als 60 {\"U}bungsaufgaben und Fallstudien inklusive ausf{\"u}hrlicher L{\"o}sungen zu ausgew{\"a}hlten Themen der Produktionswirtschaft. Jedes Kapitel enth{\"a}lt eine kurze Einleitung sowie zu erreichende Lernziele. Querverweise auf das Lehrbuch „Produktionswirtschaft" von Kellner/Lienland/Lukesch erleichtern das Selbststudium und eine optimale Pr{\"u}fungsvorbereitung. Der Inhalt Produktionsfaktoren: Mensch, Betriebsmittel, Material, Information Produktionsplanung: Lineare Programmierung, Bedarfsrechnung, Materialbedarfsplanung Produktionssteuerung: Reihenfolgeplanung Industrie 4.0 Die Autoren Maximilian Lukesch, M. Sc./MBA, ist wissenschaftlicher Mitarbeiter am Lehrstuhl f{\"u}r Betriebswirtschaftslehre, insb. Controlling und Logistik der Universit{\"a}t Regensburg. Dr. Florian Kellner ist Akademischer Rat am Lehrstuhl f{\"u}r Betriebswirtschaftslehre, insb. Controlling und Logistik der Universit{\"a}t Regensburg.}, language = {de} } @book{LukeschKellner, author = {Lukesch, Maximilian and Kellner, Florian}, title = {{\"U}bungsbuch Produktionswirtschaft : Planung, Steuerung und Industrie 4.0}, edition = {3., {\"u}berarbeitete und erweiterte Auflage}, publisher = {Springer Gabler}, address = {Berlin}, isbn = {978-3-662-68671-3}, doi = {10.1007/978-3-662-68672-0}, pages = {XVIII, 281}, abstract = {Dieses Buch bietet Studierenden {\"u}ber 80 {\"U}bungsaufgaben und f{\"u}nf Fallstudien inklusive ausf{\"u}hrlicher L{\"o}sungen zu ausgew{\"a}hlten Themen der Produktionswirtschaft und Industrie 4.0. Jedes Kapitel enth{\"a}lt eine kurze Einleitung sowie zu erreichende Lernziele. Querverweise auf das Lehrbuch „Produktionswirtschaft" von Kellner/Lienland/Lukesch erleichtern das Selbststudium und erm{\"o}glichen eine optimale Pr{\"u}fungsvorbereitung. Die 3. Auflage wurde redigiert und um neue Rechenaufgaben sowie eine weitere Fallstudie zum Themenbereich Industrie 4.0 erg{\"a}nzt.}, language = {de} } @article{LienlandKellner, author = {Lienland, Bernhard and Kellner, Florian}, title = {Projektauswahl mit der linearen Optimierung im Mittelstand}, series = {HMD Praxis der Wirtschaftsinformatik}, volume = {49}, journal = {HMD Praxis der Wirtschaftsinformatik}, publisher = {Springer}, doi = {10.1007/BF03340699}, pages = {52 -- 62}, abstract = {Die Projektauswahl stellt eine Herausforderung insbesondere f{\"u}r mittelst{\"a}ndische Industrieunternehmen dar. Abh{\"a}ngigkeiten verschiedener Alternativen und vorgegebene Investitionsbudgets f{\"u}hren bei Anwendung von in der Praxis standardm{\"a}ßig eingesetzten Verfahren regelm{\"a}ßig zu suboptimalen Projektkombinationen. In enger Abstimmung mit einem Automobilzulieferer wurde ein Ansatz zur Projektauswahl unter Ber{\"u}cksichtigung von Ressourcen und laufenden Projekten entwickelt sowie technisch umgesetzt. Implementierte Praxistests belegen Verbesserungen bei der Projektauswahl, aber auch bei der Budgeteinhaltung, der Fixkostenreduzierung sowie der Angebotspreisbestimmung.}, language = {de} } @inproceedings{SchwaegerlUhrig, author = {Schw{\"a}gerl, Felix and Uhrig, Sabrina}, title = {Tool Support for the Evaluation of Matching Algorithms in the Eclipse Modeling Framework}, series = {Proceedings of the 1st International Conference on Model-Driven Engineering and Software Development, February 19-21, 2013, in Barcelona, Spain, Vol. 1}, booktitle = {Proceedings of the 1st International Conference on Model-Driven Engineering and Software Development, February 19-21, 2013, in Barcelona, Spain, Vol. 1}, publisher = {SciTePress - Science and and Technology Publications}, isbn = {978-989-8565-42-6}, issn = {2184-4348}, doi = {10.5220/0004310801010110}, pages = {101 -- 110}, abstract = {In the field of model-driven development, sophisticated support for comparing model versions is urgently needed. Unfortunately, algorithms for model matching have been rarely evaluated so far. This paper deals with two extensions to the Eclipse Modeling Framework (EMF) that facilitate the evaluation of matching algorithms for EMF models, with the goal to combine user involvement and automated testing in the evaluation process. First a tree editor is presented that allows for the manual and semi-automated creation of match models which formalize the intended matching result. Second a benchmarking procedure is implemented which - given the intended match and the actual results of matching algorithms - automatically derives the number of a and b errors in a target-performance comparison. These results are valuable for drawing conclusions about the specific qualities of matching algorithms or for finding an adequate set of parameters for a configurable algorithm.}, language = {en} } @inproceedings{BuchmannSchwaegerl, author = {Buchmann, Thomas and Schw{\"a}gerl, Felix}, title = {Using Meta-code Generation to Realize Higher-order Model Transformations}, series = {Proceedings of the 8th International Joint Conference on Software Technologies, July 29-31, 2013, in Reykjav{\´i}k, Iceland, Vol. 1}, booktitle = {Proceedings of the 8th International Joint Conference on Software Technologies, July 29-31, 2013, in Reykjav{\´i}k, Iceland, Vol. 1}, publisher = {SciTePress - Science and and Technology Publications}, isbn = {978-989-8565-68-6}, doi = {https://doi.org/10.5220/0004522305360541}, pages = {536 -- 541}, abstract = {Model-driven engineering is a wide-spread paradigm in modern software engineering. During the last couple of years, many tools and languages have been developed, which are especially designed for model transformations — a discipline which is needed in many model-driven engineering approaches. While most of the existing model-to-model tools and languages are tailored towards batch transformations for specific model instances, they lack support for generic transformation problems, where the metamodel is unknown beforehand. In this paper we present a two-step meta-code generation approach that derives a metamodel-specific modelto- model transformation from a model-to-text transformation. The approach has been successfully applied to the problem of product derivation in model-driven software product lines.}, language = {en} } @article{PierobonSharshenova, author = {Pierobon, Chiara and Sharshenova, Aijan}, title = {German and Russian Public Diplomacy Efforts in Kyrgyzstan: A Comparative Study of Norm Entrepreneurship}, series = {Europe-Asia Studies}, volume = {75}, journal = {Europe-Asia Studies}, number = {8}, publisher = {Taylor \& Francis}, doi = {10.1080/09668136.2023.2213871}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-87380}, pages = {1384 -- 1407}, abstract = {This article explores Russian and German public diplomacy efforts in Central Asia through the example of Kyrgyzstan. Due to a difficult economic and socio-political situation, Kyrgyzstan remains open to externally funded programmes and projects, including initiatives funded by foreign governments, and thus offers a unique environment for the study of public diplomacy. The article looks at transnational public diplomacy actors such as German political foundations and Russian-sponsored organisations active in the country. Overall, the article offers interesting insights into the nature and substance of the soft power policies pursued by Germany and Russia that are relevant for Kyrgyzstan and beyond.}, language = {en} } @article{Pierobon, author = {Pierobon, Chiara}, title = {European Union, civil society and local ownership in Kyrgyzstan: analysing patterns of adaptation, reinterpretation and contestation in the prevention of violent extremism (PVE)}, series = {Central Asian Survey}, volume = {41}, journal = {Central Asian Survey}, number = {4}, publisher = {Taylor \& Francis}, doi = {10.1080/02634937.2021.1905608}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-87378}, pages = {752 -- 769}, abstract = {In the last decade, a growing body of literature has investigated the promotion of good governance, rule of law, democracy and human rights in Central Asia through funding from the European Union (EU). Most of this research has taken an EU-centric approach and is concerned with the supply side of external democratization. As a result, little is known about how EU projects are implemented on the ground and what EU-funded civil society organizations consider to be their priorities. This article investigates the agency of such organizations in Kyrgyzstan by focusing on their contribution to one particular EU instrument: the Instrument contributing to Stability and Peace (IcSP), and its programme: Strengthening Resilience to Violence and Extremism (STRIVE). The findings offer new insights into the processes of adaptation, reinterpretation and contestation through which EU-funded organizations exercise ownership while engaging in the prevention of violent extremism (PVE).}, language = {en} } @article{Pierobon, author = {Pierobon, Chiara}, title = {EU's support to civil society in Kazakhstan: A pilot evaluation of the social capital generated}, series = {Evaluation}, volume = {25}, journal = {Evaluation}, number = {2}, publisher = {Sage}, doi = {10.1177/1356389018796023}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-87394}, pages = {207 -- 223}, abstract = {In the last decade, several studies have been devoted to the analysis of the EU's support to civil society abroad, but only recently has scholarly attention turned to Central Asia. Most of the research in this field has adopted a macro-level perspective, concerned with the supply side of external democratization, and has examined external assistance to civil society in terms of democratization ideal types and typologies. The main contribution of this study consists of a meso-level analysis of the outcomes of the EU's support to civil society in terms of production of social capital, conceived as the raw material of civil society itself. More precisely, the article evaluates the first wave of grants awarded to civil society organizations in Kazakhstan as part of two EU funding schemes—the European Instrument for Democracy and Human Rights and the Non-State Actors and Local Authorities in Development. The article sheds new light on the use of social capital and its two dimensions-structural and cognitive-as heuristic tools for evaluating civil society support programs.}, language = {en} } @inproceedings{SchwaegerlUhrigWestfechtel, author = {Schw{\"a}gerl, Felix and Uhrig, Sabrina and Westfechtel, Bernhard}, title = {A Graph-based Algorithm for Three-way Merging of Ordered Collections in EMF Models}, series = {Science of Computer Programming}, volume = {113}, booktitle = {Science of Computer Programming}, number = {Part 1}, doi = {10.1016/j.scico.2015.02.008}, pages = {51 -- 81}, abstract = {In EMF models, ordered collections appear as the values of multi-valued structural features. Traditional, text-based version control systems do not sufficiently support three-way merging of ordered collections inside EMF models since they cannot guarantee a consistent result. The operation three-way merging is defined as follows: based on a common base version b, two alternative versions and were developed by copying and modifying the base version. To reconcile these changes, a merged version m is to be created as a common successor of and . In this paper, we present a graph algorithm to solve the problem of three-way merging of ordered collections in EMF models. Each version of a collection can be represented by means of a linearly ordered graph. To create the merged version, these graphs are combined to a merged collection graph using set formula. To create the merged collection, a generalized topological sort is performed on the merged collection graph. Conflicts occur in case the order of elements cannot be deduced automatically; these conflicts are resolved either interactively or by default rules. We have implemented the merge algorithm in our tool BTMerge, which performs a consistency-preserving three-way merge of versions of EMF models being instances of arbitrary Ecore models. Our implementation relies on an alternative form of representing multiple versions of a collection, namely a versioned collection graph which forms a superimposition of collection versions. The algorithm presented here is purely state-based. Matching and merging of collections are clearly separated sub-problems. Insertions and deletions performed on the elements of the collection are propagated into the merged version in a consistent way. Our algorithm makes only minimal assumptions with regard to the underlying product model and thus may be applied to ordered collections inside plain text or XML files. By taking arbitrary move operations into account, the algorithm considerably goes beyond the functionality of contemporary merge tools which cannot adequately handle move operations.}, language = {en} } @inproceedings{BuchmannSchwaegerl, author = {Buchmann, Thomas and Schw{\"a}gerl, Felix}, title = {Breaking the Boundaries of Meta Models and Preventing Information Loss in Model-Driven Software Product Lines}, series = {Proceedings of the 11th International Conference on Evaluation of Novel Software Approaches to Software Engineering, Vol 1, 2016, Rome, Italy}, booktitle = {Proceedings of the 11th International Conference on Evaluation of Novel Software Approaches to Software Engineering, Vol 1, 2016, Rome, Italy}, publisher = {SCITEPRESS - Science and and Technology Publications}, doi = {10.5220/0005789100730083}, pages = {83}, abstract = {Model-driven software product line engineering is an integrating discipline for which tool support has become available recently. However, existing tools are still immature and have several weaknesses. Among others, limitations in variability, caused by meta model restrictions, and unintended information loss are not addressed. In this paper, we present two conceptual extensions to model-driven product line engineering based on negative variability, being alternative mappings and surrogates. Alternative mappings allow for unconstrained variability, mitigating meta model restrictions by virtually extending the underlying multi-variant domain model. Surrogates prevent unintended information loss during product derivation based on a contextsensitive product analysis, which can be controlled by a declarative OCL-based language. Both extensions have been implemented in FAMILE, a model-driven product line tool that is based on EMF, provides dedicated consistency repair mechanisms, and completely automates application engineering. The added value of alternative mappings and surrogates is demonstrated by a running example.}, language = {en} } @inproceedings{SchwaegerlUhrigWestfechtel, author = {Schw{\"a}gerl, Felix and Uhrig, Sabrina and Westfechtel, Bernhard}, title = {Model-based tool support for consistent three-way merging of EMF models}, series = {ACME '13, Proceedings of the workshop on ACadeMics Tooling with Eclipse}, booktitle = {ACME '13, Proceedings of the workshop on ACadeMics Tooling with Eclipse}, publisher = {ACM}, address = {New York, NY, USA}, doi = {10.1145/2491279.2491281}, abstract = {Inadequate version control has been identified as a major obstacle to the application of model-driven software engineering. In particular, sophisticated support for merging model versions is urgently needed. We present a tool for merging of EMF models which may be applied to instances of arbitrary Ecore models. The tool advances the state of the art by guaranteeing a consistent merge result. Furthermore, it detects and resolves not only context-free, but also context-sensitive conflicts. Our merge tool is model-based; it relies on EMF for its implementation. Initial experiences gained from its application confirm that the merge tool operates both accurately and efficiently.}, language = {en} } @article{HecknerSchneidermeierHastreiteretal., author = {Heckner, Markus and Schneidermeier, Tim and Hastreiter, Isabella and Wolff, Christian}, title = {Der Newbie, der Fortgeschrittene und der Power-User. Warum es nicht reicht, "einfach mal die Nutzer zu fragen"}, series = {i-com}, volume = {11}, journal = {i-com}, number = {3}, publisher = {DeGruyter}, doi = {10.1524/icom.2012.0038}, pages = {47 -- 50}, abstract = {Innerbetriebliche Software entwickelt sich h{\"a}ufig {\"u}ber Jahre hinweg inkrementell weiter, sammelt so Schritt f{\"u}r Schritt Funktionen an und verliert an {\"U}bersichtlichkeit. Soll diese Software hinsichtlich ihrer Gebrauchstauglichkeit optimiert werden, m{\"u}ssen aus Sicht eines externen Usability-Beraters zun{\"a}chst die Dom{\"a}ne des Kunden verstanden und die Arbeitsprozesse analysiert werden. In der Analyse muss insbesondere der Umgang unterschiedlicher Nutzergruppen mit der Software ber{\"u}cksichtigt werden, um fundierte Neuvorschl{\"a}ge in einem Redesign erarbeiten zu k{\"o}nnen. In diesem Erfahrungsbericht beschreiben wir anhand eines konkreten Praxisbeispiels Eigenschaften von Nut-zergruppen und deren Einfluss auf die Analyse, und warum es nicht reicht, die Nutzer „einfach mal zu fragen, wie sie die Software denn finden".}, language = {de} } @article{HeinrichZellnerLeist, author = {Heinrich, Bernd and Zellner, Gregor and Leist, Susanne}, title = {Service integrators in business networks - The importance of relationship values}, series = {Electronic Markets}, volume = {21}, journal = {Electronic Markets}, number = {4}, publisher = {Springer}, doi = {10.1007/s12525-011-0075-x}, pages = {215 -- 235}, abstract = {To realise the potentials of CRM (customer relationship management), relationship-specific processes need to be designed and implemented in companies. This is all the more important and complicated in business networks where two or more actors collaborate to serve the customers. A good collaboration within business networks is the basis for understanding the customer process and identifying customer needs. But, even in these days of customer orientation, transaction orientation is still a matter of strong interest, and the following questions remain to be answered: What is the difference between relationship-oriented processes and transaction-oriented processes, and how can relationship-oriented processes be designed for a business network? The authors give first answers to both questions by using a systematic, goal-oriented specialisation of generic actions. To give an example, one relationship-oriented process will be designed and specified for a certain customer process in the course of this paper.}, language = {en} } @inproceedings{GriesbergerLeistZellner, author = {Griesberger, Philipp and Leist, Susanne and Zellner, Gregor}, title = {Analysis of techniques for business process improvement}, series = {19th European Conference on Information Systems, ECIS 2011, Helsinki, Finland, June 9-11, 2011}, booktitle = {19th European Conference on Information Systems, ECIS 2011, Helsinki, Finland, June 9-11, 2011}, pages = {12}, abstract = {This paper is about identifying and analyzing techniques that can be used in a business process improvement (BPI) situation. To determine suitable techniques, the term BPI is defined and criteria are derived to analyze the usability of the selected techniques. Over 300 techniques from various improvement methods were reduced to those techniques which can be applied to help improve business processes and, in particular, to support the act of improvement. Identifying these techniques is helpful, because in most cases the act of improvement is a black box that lacks guidelines or structured procedures. In our research we developed an evaluation scheme to analyze the usability of BPI techniques and give hints about how to select a suitable technique for a certain improvement situation.}, language = {en} } @article{Schoepf, author = {Sch{\"o}pf, Nicolas}, title = {Der Qualifikationsrahmen als Weg in mehr Wettbewerb? Potenziale und Herausforderungen europ{\"a}ischer Bildungspolitik f{\"u}r die Erwachsenenbildung}, series = {DIE-Zeitschrift f{\"u}r Erwachsenenbildung}, journal = {DIE-Zeitschrift f{\"u}r Erwachsenenbildung}, number = {2}, publisher = {Bertelsmann}, address = {Bielefeld}, issn = {0945-3164}, doi = {10.3278/DIE1002W045}, pages = {45 -- 48}, abstract = {Der vorliegende Beitrag sondiert Potenziale und Gef{\"a}hrdungen, die f{\"u}r die Erwachsenenbildung aus dem Prozess der Europ{\"a}isierung von Bildungspolitik resultieren. Die zugeh{\"o}rigen strukturellen Wirkmechanismen im Spannungsfeld von Kooperation und Konkurrenz belegt der Text am Beispiel des Europ{\"a}ischen Qualifikationsrahmens (EQR). Mit dem Zweck einer besseren Vergleichbarkeit von Bildungssystemen und Bildungsg{\"a}ngen geht vom EQR unweigerlich der Impuls zu mehr Wettbewerb einher, international wie national. Der Autor ordnet diese Dynamik in die {\"u}bergreifenden bildungspolitischen Prozesse ein, die mit Bolgna, Lissabon und Kopenhagen assoziiert werden.}, language = {de} } @article{Schoepf, author = {Sch{\"o}pf, Nicolas}, title = {Stiefkind Weiterbildung? Anmerkungen zur Diskussion um die Europ{\"a}isierung der Berufsbildung}, series = {Wirtschaft und Berufserziehung : W \& B ; Zeitschrift f{\"u}r Berufsbildung und Bildungspolitik}, volume = {61}, journal = {Wirtschaft und Berufserziehung : W \& B ; Zeitschrift f{\"u}r Berufsbildung und Bildungspolitik}, number = {10}, publisher = {Ziel}, address = {Augsburg}, issn = {0341-339X}, pages = {28 -- 30}, abstract = {ECVET wird gegenw{\"a}rtig haupts{\"a}chlich im Zusammenhang mit der Verbesserung und Flexibilisierung des Ausbildungssystems diskutiert, w{\"a}hrend die berufliche Weiterbildung noch eine untergeordnete Rolle spielt. Der Beitrag beleuchtet Ankn{\"u}pfungspunkte und Handlungsfelder f{\"u}r die berufliche Weiterbildung. Als Handlungsfelder r{\"u}cken Transparenz und Vergleichbarkeit der Weiterbildungsergebnisse und Transparenz und Vergleichbarkeit ausl{\"a}ndischer Qualifikationen in den Blick. ECVET k{\"o}nnte heterogene Prozesse der Weiterbildung angesichts standardisiert beschriebener Lernergebnisse vergleichbar und erzielte Kompetenzen {\"u}ber regionale und tr{\"a}gerbezogene Grenzen hinweg verwertbar machen. (BIBB-Doku).}, language = {de} } @article{Schoepf, author = {Sch{\"o}pf, Nicolas}, title = {Lernergebnisse - Schl{\"u}ssel f{\"u}r die Verst{\"a}ndigung in Europa? Perspektiven f{\"u}r die Erwachsenen- und Weiterbildung}, series = {Bildung f{\"u}r Europa : Journal der Nationalen Agentur beim Bundesinstitut f{\"u}r Berufsbildung}, journal = {Bildung f{\"u}r Europa : Journal der Nationalen Agentur beim Bundesinstitut f{\"u}r Berufsbildung}, number = {15}, publisher = {Nationale Agentur beim Bundesinstitut f{\"u}r Berufsbildung}, issn = {1616-5837}, pages = {33 -- 34}, language = {de} } @article{Schoepf, author = {Sch{\"o}pf, Nicolas}, title = {Die Qual der Wahl. Fragen der Weiterbildungsorganisation und des Einsatzes von eLearning in Unternehmen}, series = {IT-Mittelstand}, journal = {IT-Mittelstand}, number = {12}, publisher = {MEDIENHAUS Verlag GmbH}, pages = {54 -- 58}, language = {de} } @article{Schoepf, author = {Sch{\"o}pf, Nicolas}, title = {Anst{\"o}ße aus Europa}, series = {Personal}, journal = {Personal}, number = {4}, pages = {18 -- 20}, language = {de} } @article{Schoepf, author = {Sch{\"o}pf, Nicolas}, title = {Grenzkontrollen. Erleichtert die {\"O}ffnung von Bildungswegen kontinuierliches Lernen?}, series = {Berufs- und Wirtschaftsp{\"a}dagogik Online}, journal = {Berufs- und Wirtschaftsp{\"a}dagogik Online}, number = {18}, publisher = {bwp}, issn = {0945-3164}, pages = {20}, abstract = {"Individuelle Bildungsverl{\"a}ufe sind nur zu einem Teil das Ergebnis aktiver pers{\"o}nlicher Planung und Steuerung. Oftmals sind sie das Resultat von Selektion, systemischen Schranken und Abschottungen zwischen Teilen des Bildungssystems. Die Grenzen, die es auf individuellen Bildungspfaden zu {\"u}berschreiten gilt, sind vielf{\"a}ltig: Sie existieren zwischen Jahrgangsklassen, zwischen Grund- und weiterf{\"u}hrenden Schulen bis hin zur Hochschule oder zwischen {\"U}bergangssystem, beruflicher und akademischer Bildung. Gegenw{\"a}rtig verbindet sich insbesondere mit Ans{\"a}tzen der Europ{\"a}isierung der Aus- und Weiterbildung die Hoffnung, Bildungswege zu {\"o}ffnen und damit die M{\"o}glichkeiten lebenslanges Lernen zu erweitern: Die Rede ist dabei von einer Verbesserung der transnationalen Mobilit{\"a}t der Lernenden und der Durchl{\"a}ssigkeit nationaler Bildungssysteme. Es geht dabei also um die Anerkennung von Lernergebnissen, die im Ausland erzielt wurden, und ihre Anrechnung auf deutsche Bildungsg{\"a}nge und um die Anerkennung und Anrechnung von Lernergebnissen zwischen Subsystemen der Bildung in Deutschland. Die Debatte um Durchl{\"a}ssigkeit macht dabei auf mehrere Aspekte aufmerksam: Die Frage, unter welchen Gesichtspunkten Anerkennung diskutiert wird, verweist unter anderem auf das klassische Verh{\"a}ltnis von Qualifizierung und Bildung, von Speziellem und Allgemeinem der Bildung. Damit verkn{\"u}pft stellt sich zudem die Frage, inwieweit auch das Thema Durchl{\"a}ssigkeit eine Rolle f{\"u}r Entwicklungen spielt, die gegenw{\"a}rtig als Neuvermessung des Bildungssystems diskutiert werden." (Autorenreferat; BIBB-Doku).}, language = {de} } @article{Zuerner, author = {Z{\"u}rner, Christian}, title = {Religi{\"o}se Bildung in der s{\"a}kularisierten Gesellschaft. Grundsatz{\"u}berlegungen mit Bezug auf den Philosophen J{\"u}rgen Habermas}, series = {Freies Christentum : auf der Suche nach neuen Wegen}, volume = {59}, journal = {Freies Christentum : auf der Suche nach neuen Wegen}, number = {3}, issn = {0931-3834}, pages = {67 -- 69}, language = {de} } @article{ThiemeLangerBehrens, author = {Thieme, Dorothea and Langer, G. and Behrens, Johann}, title = {Das Wissen Pflegender zur Kompressionstherapie - Studie zur Therapie der akuten tiefen Beinvenenthrombose}, series = {Pflegezeitschrift}, volume = {62}, journal = {Pflegezeitschrift}, number = {5}, pages = {296 -- 301}, language = {de} } @article{ThiemeLandenberger, author = {Thieme, Dorothea and Landenberger, M.}, title = {Therapie der akuten tiefen Beinvenenthrombose - eine Literaturrecherche: Verbandtechniken im Vergleich}, series = {Pflegezeitschrift}, volume = {62}, journal = {Pflegezeitschrift}, number = {4}, pages = {206 -- 209}, language = {de} } @article{ThiemeLangerBehrens, author = {Thieme, Dorothea and Langer, G. and Behrens, Johann}, title = {Befragung Pflegender zur Kompressionstherapie bei akuter tiefer Beinvenenthrombose}, series = {Pflegezeitschrift}, volume = {63}, journal = {Pflegezeitschrift}, number = {3}, pages = {162 -- 167}, language = {de} } @article{Zuerner, author = {Z{\"u}rner, Christian}, title = {... geheimnisvolle Dinge, die ich in Worten nicht aufsetzen kann : {\"A}sthetik in der religi{\"o}sen Bildung}, series = {Evangelische Aspekte}, volume = {16}, journal = {Evangelische Aspekte}, number = {1}, pages = {27 -- 30}, language = {de} } @article{Zuerner, author = {Z{\"u}rner, Christian}, title = {Auf der Suche nach Identit{\"a}t…}, series = {Arnoldshainer Akzente : Nachrichten aus der Evangelischen Akademie}, journal = {Arnoldshainer Akzente : Nachrichten aus der Evangelischen Akademie}, number = {1}, issn = {0934-7119}, pages = {7}, language = {de} } @article{Schoepf, author = {Sch{\"o}pf, Nicolas}, title = {Mit Kompetenzp{\"a}ssen die Talente ihrer Mitarbeiter kennen und entwickeln}, series = {Personal im Fokus}, journal = {Personal im Fokus}, number = {8}, pages = {30 -- 32}, language = {de} } @article{SchoepfIselerSausele, author = {Sch{\"o}pf, Nicolas and Iseler, K. and Sausele, I.}, title = {Persistenz und Verschwinden. P{\"a}dagogische Organisationen im historischen Kontext}, series = {Zeitschrift f{\"u}r Soziologie der Erziehung und Sozialisation}, volume = {27}, journal = {Zeitschrift f{\"u}r Soziologie der Erziehung und Sozialisation}, number = {4}, publisher = {Beltz Juventa}, issn = {1436-1957}, pages = {442 -- 447}, language = {de} } @article{OttRosengarthDoenitzetal., author = {Ott, Christian and Rosengarth, Katharina and Doenitz, Christian and Hoehne, Julius and Wendl, Christina and Dodoo-Schittko, Frank and Lang, Elmar Wolfgang and Schmidt, Nils Ole and Goldhacker, Markus}, title = {Preoperative Assessment of Language Dominance through Combined Resting-State and Task-Based Functional Magnetic Resonance Imaging}, series = {Journal of personalized medicine}, volume = {11}, journal = {Journal of personalized medicine}, number = {12}, publisher = {MDPI}, doi = {10.3390/jpm11121342}, abstract = {Brain lesions in language-related cortical areas remain a challenge in the clinical routine. In recent years, the resting-state fMRI (RS-fMRI) was shown to be a feasible method for preoperative language assessment. The aim of this study was to examine whether language-related resting-state components, which have been obtained using a data-driven independent-component-based identification algorithm, can be supportive in determining language dominance in the left or right hemisphere. Twenty patients suffering from brain lesions close to supposed language-relevant cortical areas were included. RS-fMRI and task-based (TB-fMRI) were performed for the purpose of preoperative language assessment. TB-fMRI included a verb generation task with an appropriate control condition (a syllable switching task) to decompose language-critical and language-supportive processes. Subsequently, the best fitting ICA component for the resting-state language network (RSLN) referential to general linear models (GLMs) of the TB-fMRI (including models with and without linguistic control conditions) was identified using an algorithm based on the Dice index. Thereby, the RSLNs associated with GLMs using a linguistic control condition led to significantly higher laterality indices than GLM baseline contrasts. LIs derived from GLM contrasts with and without control conditions alone did not differ significantly. In general, the results suggest that determining language dominance in the human brain is feasible both with TB-fMRI and RS-fMRI, and in particular, the combination of both approaches yields a higher specificity in preoperative language assessment. Moreover, we can conclude that the choice of the language mapping paradigm is crucial for the mentioned benefits.}, language = {en} } @misc{OttRosengarthDoenitzetal., author = {Ott, Christian and Rosengarth, K. and Doenitz, Christian and Hoehne, Julius and Wendl, C. and Dodoo-Schittko, Frank and Lang, Elmar Wolfgang and Schmidt, Nils Ole and Goldhacker, Markus}, title = {Preoperative assessment of language dominance through combined resting-state and task-based functional magnetic resonance imaging}, series = {Brain and Spine}, volume = {1}, journal = {Brain and Spine}, number = {Suppl. 2}, publisher = {Elsevier}, doi = {10.1016/j.bas.2021.100523}, abstract = {Background: Brain lesions in language-related cortical areas remain a challenge in the clinical routine. In recent years the resting-state fMRI (rs-fMRI) was shown to be a feasible method for preoperative language assessment. The aim of this study was to examine whether language-related resting-state components, which have been obtained using a data-driven independent-component-based identification algorithm, can be supportive in determining language dominance in the left or right hemisphere. Methods: Twenty patients suffering from brain lesions close to supposed language relevant cortical areas were included. Rs-fMRI and task-based (tb-fMRI) were performed for the purpose of preoperative language assessment. Tb-fMRI included a verb generation task with an appropriate control condition (a syllable switching task) to decompose language critical and language supportive processes. Subsequently, the best fitting ICA component for the resting-state language network (RSLN) referential to general linear models (GLMs) of the tb-fMRI (including models with and without linguistic control conditions) was identified using an algorithm based on the Dice-index. Results: The RSLNs associated with GLMs using a linguistic control condition led to significantly higher laterality indices than GLM baseline contrasts. LIs derived from GLM contrasts with and without control conditions alone did not differ significantly. Conclusion: In general, the results suggest that determining language dominance in the human brain is feasible both with tb-fMRI and rs-fMRI, and in particular, the combination of both approaches yields a higher specificity in preoperative language assessment. Moreover, we can conclude that the choice of the language mapping paradigm is crucial for the mentioned benefits.}, language = {en} } @article{GoldhackerTomeGreenleeetal., author = {Goldhacker, Markus and Tom{\´e}, Ana Maria and Greenlee, Mark W. and Lang, Elmar Wolfgang}, title = {Frequency-Resolved Dynamic Functional Connectivity Reveals Scale-Stable Features of Connectivity-States}, series = {Frontiers in Human Neuroscience}, volume = {12}, journal = {Frontiers in Human Neuroscience}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1662-5161}, doi = {10.3389/fnhum.2018.00253}, pages = {1 -- 16}, abstract = {Investigating temporal variability of functional connectivity is an emerging field in connectomics. Entering dynamic functional connectivity by applying sliding window techniques on resting-state fMRI (rs-fMRI) time courses emerged from this topic. We introduce frequency-resolved dynamic functional connectivity (frdFC) by means of multivariate empirical mode decomposition (MEMD) followed up by filter-bank investigations. In general, we find that MEMD is capable of generating time courses to perform frdFC and we discover that the structure of connectivity-states is robust over frequency scales and even becomes more evident with decreasing frequency. This scale-stability varies with the number of extracted clusters when applying k-means. We find a scale-stability drop-off from k = 4 to k = 5 extracted connectivity-states, which is corroborated by null-models, simulations, theoretical considerations, filter-banks, and scale-adjusted windows. Our filter-bank studies show that filter design is more delicate in the rs-fMRI than in the simulated case. Besides offering a baseline for further frdFC research, we suggest and demonstrate the use of scale-stability as a possible quality criterion for connectivity-state and model selection. We present first evidence showing that connectivity-states are both a multivariate, and a multiscale phenomenon. A data repository of our frequency-resolved time-series is provided.}, language = {en} } @article{FellnerVolbergWimberetal., author = {Fellner, Marie-Christin and Volberg, Gregor and Wimber, Maria and Goldhacker, Markus and Greenlee, Mark W. and Hanslmayr, Simon}, title = {Spatial mnemonic encoding: Theta power decreases and medial temporal lobe BOLD increases co-occur during the usage of the method of loci}, series = {eNeuro}, volume = {3}, journal = {eNeuro}, number = {6}, publisher = {Society for Neuroscience}, address = {Washington, DC}, issn = {2373-2822}, doi = {10.1523/ENEURO.0184-16.2016}, pages = {1 -- 16}, abstract = {The method of loci is one, if not the most, efficient mnemonic encoding strategy. This spatial mnemonic combines the core cognitive processes commonly linked to medial temporal lobe (MTL) activity: spatial and associative memory processes. During such processes, fMRI studies consistently demonstrate MTL activity, while electrophysiological studies have emphasized the important role of theta oscillations (3-8 Hz) in the MTL. However, it is still unknown whether increases or decreases in theta power co-occur with increased BOLD signal in the MTL during memory encoding. To investigate this question, we recorded EEG and fMRI separately, while human participants used the spatial method of loci or the pegword method, a similarly associative but nonspatial mnemonic. The more effective spatial mnemonic induced a pronounced theta power decrease source localized to the left MTL compared with the nonspatial associative mnemonic strategy. This effect was mirrored by BOLD signal increases in the MTL. Successful encoding, irrespective of the strategy used, elicited decreases in left temporal theta power and increases in MTL BOLD activity. This pattern of results suggests a negative relationship between theta power and BOLD signal changes in the MTL during memory encoding and spatial processing. The findings extend the well known negative relation of alpha/beta oscillations and BOLD signals in the cortex to theta oscillations in the MTL.}, language = {en} } @article{GoldhackerKeckIgeletal., author = {Goldhacker, Markus and Keck, P. and Igel, A. and Lang, Elmar Wolfgang and Tom{\´e}, Ana Maria}, title = {A multi-variate blind source separation algorithm}, series = {Computer Methods and Programs in Biomedicine}, volume = {151}, journal = {Computer Methods and Programs in Biomedicine}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1872-7565}, doi = {10.1016/j.cmpb.2017.08.019}, pages = {91 -- 99}, abstract = {Background and objective The study follows the proposal of decomposing a given data matrix into a product of independent spatial and temporal component matrices. A multi-variate decomposition approach is presented, based on an approximate diagonalization of a set of matrices computed using a latent space representation. Methods The proposed methodology follows an algebraic approach, which is common to space, temporal or spatiotemporal blind source separation algorithms. More specifically, the algebraic approach relies on singular value decomposition techniques, which avoids computationally costly and numerically instable matrix inversion. The method is equally applicable to correlation matrices determined from second order correlations or by considering fourth order correlations. Results The resulting algorithms are applied to fMRI data sets either to extract the underlying fMRI components or to extract connectivity maps from resting state fMRI data collected for a dynamic functional connectivity analysis. Intriguingly, our algorithm shows increased spatial specificity compared to common approaches, while temporal precision stays similar. Conclusion The study presents a novel spatiotemporal blind source separation algorithm, which is both robust and avoids parameters that are difficult to fine tune. Applied on experimental data sets, the new method yields highly confined and focused areas with least spatial extent in the retinotopy case, and similar results in the dynamic functional connectivity analyses compared to other blind source separation algorithms. Therefore, we conclude that our novel algorithm is highly competitive and yields results, which are superior or at least similar to existing approaches.}, language = {en} } @article{WeinDecoTomeetal., author = {Wein, Simon and Deco, Gustavo and Tom{\´e}, Ana Maria and Goldhacker, Markus and Malloni, Wilhelm M. and Greenlee, Mark W. and Lang, Elmar Wolfgang}, title = {Brain Connectivity Studies on Structure-Function Relationships: A Short Survey with an Emphasis on Machine Learning}, series = {Computational intelligence and neuroscience}, journal = {Computational intelligence and neuroscience}, publisher = {Hindawi}, doi = {10.1155/2021/5573740}, pages = {1 -- 31}, abstract = {This short survey reviews the recent literature on the relationship between the brain structure and its functional dynamics. Imaging techniques such as diffusion tensor imaging (DTI) make it possible to reconstruct axonal fiber tracks and describe the structural connectivity (SC) between brain regions. By measuring fluctuations in neuronal activity, functional magnetic resonance imaging (fMRI) provides insights into the dynamics within this structural network. One key for a better understanding of brain mechanisms is to investigate how these fast dynamics emerge on a relatively stable structural backbone. So far, computational simulations and methods from graph theory have been mainly used for modeling this relationship. Machine learning techniques have already been established in neuroimaging for identifying functionally independent brain networks and classifying pathological brain states. This survey focuses on methods from machine learning, which contribute to our understanding of functional interactions between brain regions and their relation to the underlying anatomical substrate.}, language = {en} } @inproceedings{WostmannSchlunderTemmeetal., author = {Wostmann, Rene and Schlunder, Philipp and Temme, Fabian and Klinkenberg, Ralf and Kimberger, Josef and Spichtinger, Andrea and Goldhacker, Markus and Deuse, Jochen}, title = {Conception of a Reference Architecture for Machine Learning in the Process Industry}, series = {2020 IEEE International Conference on Big Data (Big Data): 10.12.2020 - 13.12.2020 Atlanta, GA, USA}, booktitle = {2020 IEEE International Conference on Big Data (Big Data): 10.12.2020 - 13.12.2020 Atlanta, GA, USA}, publisher = {IEEE}, isbn = {978-1-7281-6251-5}, doi = {10.1109/bigdata50022.2020.9378290}, pages = {1726 -- 1735}, abstract = {The increasing global competition demands continuous optimization of products and processes from companies in the process industry. Where conventional methods of Lean Management and Six Sigma reach their limits, new opportunities and challenges arise through increasing connectivity in the Industrial Internet of Things and machine learning. The majority of industrial projects do not reach the deployment or are isolated solutions, as the structures for data integration, training, deployment and maintenance of models are not established. This paper presents the conception of a reference architecture for machine learning in the process industry to support companies in implementing their own specific structures. The focus is on the development process and an exemplary implementation in the brewing industry.}, language = {en} } @article{PlankRosengarthSchmalhoferetal., author = {Plank, Tina and Rosengarth, Katharina and Schmalhofer, Carolin and Goldhacker, Markus and Brandl-R{\"u}hle, Sabine and Greenlee, Mark W.}, title = {Perceptual learning in patients with macular degeneration}, series = {Frontiers in psychology}, volume = {5}, journal = {Frontiers in psychology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-1078}, doi = {10.3389/fpsyg.2014.01189}, pages = {1 -- 14}, abstract = {Patients with age-related macular degeneration (AMD) or hereditary macular dystrophies (JMD) rely on an efficient use of their peripheral visual field. We trained eight AMD and five JMD patients to perform a texture-discrimination task (TDT) at their preferred retinal locus (PRL) used for fixation. Six training sessions of approximately one hour duration were conducted over a period of approximately 3 weeks. Before, during and after training twelve patients and twelve age-matched controls (the data from two controls had to be discarded later) took part in three functional magnetic resonance imaging (fMRI) sessions to assess training-related changes in the BOLD response in early visual cortex. Patients benefited from the training measurements as indexed by significant decrease (p = 0.001) in the stimulus onset asynchrony (SOA) between the presentation of the texture target on background and the visual mask, and in a significant location specific effect of the PRL with respect to hit rate (p = 0.014). The following trends were observed: (i) improvement in Vernier acuity for an eccentric line-bisection task; (ii) positive correlation between the development of BOLD signals in early visual cortex and initial fixation stability (r = 0.531); (iii) positive correlation between the increase in task performance and initial fixation stability (r = 0.730). The first two trends were non-significant, whereas the third trend was significant at p = 0.014, Bonferroni corrected. Consequently, our exploratory study suggests that training on the TDT can enhance eccentric vision in patients with central vision loss. This enhancement is accompanied by a modest alteration in the BOLD response in early visual cortex.}, language = {en} } @misc{GreenleeAnstisRosengarthetal., author = {Greenlee, Mark W. and Anstis, Stuart and Rosengarth, Katharina and Goldhacker, Markus and Brandl-R{\"u}hle, Sabine and Plank, Tina}, title = {Neural correlates of perceptual filling-in: fMRI evidence in the foveal projection zone of patients with central scotoma}, series = {Journal of Vision / Vision Sciences Society Annual Meeting Abstract}, volume = {12}, journal = {Journal of Vision / Vision Sciences Society Annual Meeting Abstract}, number = {9}, publisher = {ARVO}, issn = {1534-7362}, doi = {10.1167/12.9.1303}, abstract = {Patients with juvenile retinal dystrophy often report that they are unaware of their central scotoma, suggesting the presence of perceptual filling-in. We used functional Magnetic Resonance Imaging (fMRI) to determine possible neural correlates of perceptual filling-in in patients with retinal distrophy and clinically established central scotoma in both eyes. The data of 5 patients (Stargardt disease, cone-rod dystrophy; mean age 45 yrs; scotoma diameter 10-20°) and of 5 normally sighted controls were analyzed. Fixation behaviour and perimetry were measured with a Nidek microperimeter. Magnetic resonance imaging was performed using a Siemens 3T Allegra scanner. We stimulated the central visual field (30 deg) with a vertically oriented, low spatial frequency (1 c/deg) high-contrast sinewave grating that was either a) continuous, or b) was interrupted by a central grey disk. The disk was either slightly larger than the scotoma (detectable on 75\% of trials) or slightly smaller (detectable on 25\% of trials). To control for attention, an eccentric fixation task was performed during scanning. Data were analyzed using SPM8 (GLM with ROI analysis to obtain percent signal change for foveal projection zone). Results: for all patients, the BOLD signal in the foveal projection area was significantly higher for the small disk (i.e., condition leading to complete filling-in) than for the large disk (i.e., no filling-in). This effect was absent in the control subjects. Our findings support the existence of an active neural process that leads to filling-in in patients with central visual field scotomata.}, language = {en} } @article{GoldhackerRosengarthPlanketal., author = {Goldhacker, Markus and Rosengarth, Katharina and Plank, Tina and Greenlee, Mark W.}, title = {The effect of feedback on performance and brain activation during perceptual learning}, series = {Vision research}, volume = {99}, journal = {Vision research}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1878-5646}, doi = {10.1016/j.visres.2013.11.010}, pages = {99 -- 110}, abstract = {We investigated the role of informative feedback on the neural correlates of perceptual learning in a coherent-motion detection paradigm. Stimulus displays consisted of four patches of moving dots briefly (500 ms) presented simultaneously, one patch in each visual quadrant. The coherence level was varied in the target patch from near threshold to high, while the other three patches contained only noise. The participants judged whether coherent motion was present or absent in the target patch. To guarantee central fixation, a secondary RSVP digit-detection task was performed at fixation. Over six training sessions subjects learned to detect coherent motion in a predefined quadrant (i.e., the learned location). Half of our subjects were randomly assigned to the feedback group, where they received informative feedback after each response during training, whereas the other group received non-informative feedback during training that a response button was pressed. We investigated whether the presence of informative feedback during training had an influence on the learning success and on the resulting BOLD response. Behavioral data of 24 subjects showed improved performance with increasing practice. Informative feedback promoted learning for motion displays with high coherence levels, whereas it had little effect on learning for displays with near-threshold coherence levels. Learning enhanced fMRI responses in early visual cortex and motion-sensitive area MT+ and these changes were most pronounced for high coherence levels. Activation in the insular and cingulate cortex was mainly influenced by coherence level and trained location. We conclude that feedback modulates behavioral performance and, to a lesser extent, brain activation in areas responsible for monitoring perceptual learning.}, language = {en} } @inproceedings{WeinTomeGoldhackeretal., author = {Wein, S. and Tom{\´e}, Ana Maria and Goldhacker, Markus and Greenlee, Mark W. and Lang, Elmar Wolfgang}, title = {Hybridizing EMD with cICA for fMRI Analysis of Patient Groups}, series = {2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC): 23-27 July 2019, Berlin, Germany}, booktitle = {2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC): 23-27 July 2019, Berlin, Germany}, publisher = {IEEE}, doi = {10.1109/EMBC.2019.8856355}, pages = {194 -- 197}, abstract = {Independent component analysis (ICA), as a data driven method, has shown to be a powerful tool for functional magnetic resonance imaging (fMRI) data analysis. One drawback of this multivariate approach is, that it is naturally not convenient for analysis of group studies. Therefore various techniques have been proposed in order to overcome this limitation of ICA. In this paper a novel ICA based work-flow for extracting resting state networks from fMRI group studies is proposed. An empirical mode decomposition (EMD) is used to generate reference signals in a data driven manner, which can be incorporated into a constrained version of ICA (cICA), what helps to overcome the inherent ambiguities. The results of the proposed workflow are then compared to those obtained by a widely used group ICA approach. It is demonstrated that intrinsic modes, extracted by EMD, are suitable to serve as references for cICA to obtain typical resting state patterns, which are consistent over subjects. This novel processing pipeline makes it transparent for the user, how comparable activity patterns across subjects emerge, and also the trade-off between similarity across subjects and preserving individual features can be well adjusted and adapted for different requirements in the new work-flow.}, language = {en} } @article{GoldhackerFellnerVolbergetal., author = {Goldhacker, Markus and Fellner, Marie-Christin and Volberg, G. and Mullinger, K. J. and Greenlee, Mark W. and Hanslmayr, Simon}, title = {Spurious correlations in simultaneous EEG-fMRI driven by in-scanner movement}, series = {NeuroImage}, volume = {133}, journal = {NeuroImage}, number = {June}, publisher = {Elsevier}, doi = {10.1016/j.neuroimage.2016.03.031}, pages = {354 -- 366}, abstract = {Simultaneous EEG-fMRI provides an increasingly attractive research tool to investigate cognitive processes with high temporal and spatial resolution. However, artifacts in EEG data introduced by the MR scanner still remain a major obstacle. This study, employing commonly used artifact correction steps, shows that head motion, one overlooked major source of artifacts in EEG-fMRI data, can cause plausible EEG effects and EEG-BOLD correlations. Specifically, low-frequency EEG (< 20 Hz) is strongly correlated with in-scanner movement. Accordingly, minor head motion (< 0.2 mm) induces spurious effects in a twofold manner: Small differences in task-correlated motion elicit spurious low-frequency effects, and, as motion concurrently influences fMRI data, EEG-BOLD correlations closely match motion-fMRI correlations. We demonstrate these effects in a memory encoding experiment showing that obtained theta power (~ 3-7 Hz) effects and channel-level theta-BOLD correlations reflect motion in the scanner. These findings highlight an important caveat that needs to be addressed by future EEG-fMRI studies.}, language = {en} } @article{WeinTomeGoldhackeretal., author = {Wein, Simon and Tom{\´e}, Ana Maria and Goldhacker, Markus and Greenlee, Mark W. and Lang, Elmar Wolfgang}, title = {A Constrained ICA-EMD Model for Group Level fMRI Analysis}, series = {Frontiers in Neuroscience}, volume = {14}, journal = {Frontiers in Neuroscience}, publisher = {frontiers}, issn = {1662-453X}, doi = {10.3389/fnins.2020.00221}, pages = {1 -- 10}, abstract = {Independent component analysis (ICA), being a data-driven method, has been shown to be a powerful tool for functional magnetic resonance imaging (fMRI) data analysis. One drawback of this multivariate approach is that it is not, in general, compatible with the analysis of group data. Various techniques have been proposed to overcome this limitation of ICA. In this paper, a novel ICA-based workflow for extracting resting-state networks from fMRI group studies is proposed. An empirical mode decomposition (EMD) is used, in a data-driven manner, to generate reference signals that can be incorporated into a constrained version of ICA (cICA), thereby eliminating the inherent ambiguities of ICA. The results of the proposed workflow are then compared to those obtained by a widely used group ICA approach for fMRI analysis. In this study, we demonstrate that intrinsic modes, extracted by EMD, are suitable to serve as references for cICA. This approach yields typical resting-state patterns that are consistent over subjects. By introducing these reference signals into the ICA, our processing pipeline yields comparable activity patterns across subjects in a mathematically transparent manner. Our approach provides a user-friendly tool to adjust the trade-off between a high similarity across subjects and preserving individual subject features of the independent components.}, language = {en} } @article{GoldhackerAlSubariAlBaddaietal., author = {Goldhacker, Markus and Al-Subari, Karema and Al-Baddai, Saad and Tom{\´e}, Ana Maria and Faltermeier, Rupert and Lang, Elmar Wolfgang}, title = {EMDLAB: A toolbox for analysis of single-trial EEG dynamics using empirical mode decomposition}, series = {Journal of Neuroscience Methods}, volume = {253}, journal = {Journal of Neuroscience Methods}, number = {September}, publisher = {Elsevier}, address = {AMsterdam}, doi = {10.1016/j.jneumeth.2015.06.020}, pages = {193 -- 205}, abstract = {Background: Empirical mode decomposition (EMD) is an empirical data decomposition technique. Recently there is growing interest in applying EMD in the biomedical field. New method: EMDLAB is an extensible plug-in for the EEGLAB toolbox, which is an open software environment for electrophysiological data analysis. Results: EMDLAB can be used to perform, easily and effectively, four common types of EMD: plain EMD, ensemble EMD (EEMD), weighted sliding EMD (wSEMD) and multivariate EMD (MEMD) on EEG data. In addition, EMDLAB is a user-friendly toolbox and closely implemented in the EEGLAB toolbox. Comparison with existing methods: EMDLAB gains an advantage over other open-source toolboxes by exploiting the advantageous visualization capabilities of EEGLAB for extracted intrinsic mode functions (IMFs) and Event-Related Modes (ERMs) of the signal. Conclusions: EMDLAB is a reliable, efficient, and automated solution for extracting and visualizing the extracted IMFs and ERMs by EMD algorithms in EEG study.}, language = {en} } @inproceedings{GoldhackerTomeGreenleeetal., author = {Goldhacker, Markus and Tom{\´e}, Ana Maria and Greenlee, Mark W. and Lang, Elmar Wolfgang}, title = {Early meta-level: deeper understanding of connectivity-states and consequences for state definition}, series = {21st Annual Meeting of the Organization for Human Brain Mapping, June 14-18, 2015, Honolulu, Hawaii}, booktitle = {21st Annual Meeting of the Organization for Human Brain Mapping, June 14-18, 2015, Honolulu, Hawaii}, publisher = {Academic Press}, address = {San Diego, CA}, doi = {10.13140/RG.2.1.2561.3929}, language = {en} } @misc{AlSubariAlBaddaiTomeetal., author = {Al-Subari, Karema and Al-Baddai, Saad and Tom{\´e}, Ana Maria and Goldhacker, Markus and Faltermeier, Rupert and Lang, Elmar Wolfgang}, title = {EMDLAB-toolbox- tutorial video}, language = {en} } @article{GreenleeRosengarthSchmalhoferetal., author = {Greenlee, Mark W. and Rosengarth, Katharina and Schmalhofer, Carolin and Goldhacker, Markus and Brandl-R{\"u}hle, Sabine and Plank, Tina}, title = {Perceptual learning in patients with central scotomata due to hereditary and age-related macular dystrophy}, series = {Journal of Vision}, volume = {14}, journal = {Journal of Vision}, number = {10}, publisher = {ARVO}, issn = {1468-4233}, doi = {10.1167/14.10.666}, abstract = {Hereditary and age-related forms of macular dystrophy (MD) are characterized by loss of cone function in the fovea, leading to central scotomata and eccentric fixation at the so-called preferred retinal locus (PRL). We investigated whether perceptual learning enhances visual abilities at the PRL. We also determined the neural correlates (3-Tesla fMRI) of learning success. Twelve MD patients (eight with age-related macular dystrophy, four with hereditary macular dystrophies) were trained on a texture discrimination task (TDT) over six days. Patients underwent three fMRI sessions (before, during and after training) while performing the TDT (target at PRL or opposite PRL). Reading speed, visual acuity (Vernier task) and contrast sensitivity were also assessed before and after training. With one exception, all patients showed improved performance (i.e. significant decrease in stimulus onset asynchronies and reaction times, significant increase in hit rates) on the TDT. Eight patients also showed moderate increases in reading speed, six patients showed improved thresholds in contrast sensitivity and nine patients showed improved thresholds in a vernier visual acuity task after TDT training. We found an increase in BOLD response in the projections zone of the PRL in the primary visual cortex in nine of twelve patients after training. The change in fMRI signal correlated (r = .8; p = .02) with the patients{\^a}€™ performance enhancements when the target was in the PRL. The results suggest that perceptual learning can enhance eccentric vision and cortical processing in MD patients.}, language = {en} } @article{GoldhackerRosengarthAnstisetal., author = {Goldhacker, Markus and Rosengarth, Katharina and Anstis, Stuart and Wirth, Anna and Plank, Tina and Greenlee, Mark W.}, title = {FMRI evidence for perceptual filling-in in patients with macular dystrophy}, series = {Perception}, volume = {42}, journal = {Perception}, issn = {1468-4233}, pages = {72 -- 73}, language = {en} } @book{SchultzJain, author = {Schultz, David and Jain, Brijnesh}, title = {Nonsmooth Analysis and Subgradient Methods for Averaging in Dynamic Time Warping Spaces}, doi = {10.48550/arXiv.1701.06393}, pages = {30}, abstract = {Time series averaging in dynamic time warping (DTW) spaces has been successfully applied to improve pattern recognition systems. This article proposes and analyzes subgradient methods for the problem of finding a sample mean in DTW spaces. The class of subgradient methods generalizes existing sample mean algorithms such as DTW Barycenter Averaging (DBA). We show that DBA is a majorize-minimize algorithm that converges to necessary conditions of optimality after finitely many iterations. Empirical results show that for increasing sample sizes the proposed stochastic subgradient (SSG) algorithm is more stable and finds better solutions in shorter time than the DBA algorithm on average. Therefore, SSG is useful in online settings and for non-small sample sizes. The theoretical and empirical results open new paths for devising sample mean algorithms: nonsmooth optimization methods and modified variants of pairwise averaging methods.}, language = {en} }