1,720,989 research outputs found
Non-invasive, virtual unpacking of enclosed cuneiform - 3D reconstruction and visualization of clay tablets based on data acquired by portable micro-CT scanner
No full textIn this video animation we visualize the reconstruction of an enclosed cuneiform tablet (Louvre Museum, collection no. AO8295, 19th century BC, showing a loan contract, 5.9 cm x 6.1 cm x 2.1 cm) and the envelope. The surface reconstruction, feature analysis, segmentation, and visualization was performed by "EXAVIS42" - which was developed by the author, as part of the project - from high-resolution volume data (38 µm voxel size), acquired by the portable micro-CT scanner "ENCI" - constructed as part of the project - at the collection of the Louvre Museum (Paris). The cuneiform signs are emphasized by a diffuse lighting model, combined with curvature-oriented highlighting and darkening, and shadowing by precalculated ambient occlusion, implementing an optimized function for weighting orientations of rays and their distances of crossed surfaces. The video clip was exported from "EXAVIS42" as a sequence of 4.850 anti-aliased images in 1920x1080 resolution (50 frames per second), off-screen rendered in OpenGL, by taking advantage of key frame animation, interpolating camera positions and orientations, as well as numerous visualization parameters.
This video animation was first published as part of the report about the project in German television: "Forscher entschlüsseln die Geheimnisse antiker Keilschriften", Norddeutscher Rundfunk (NDR), 22.03.2024, https://www.ardmediathek.de/video/hamburg-journal/forscher-entschluesseln-die-geheimnisse-antiker-keilschriften/ndr/Y3JpZDovL25kci5kZS9hMzdiYjQ1YS1iYmMxLTQ5NGUtOTk1Yi0wM2NmYzNlYzlhNjQ (attached 25.06.2024, available until 22.03.2026).
For version 2, annotations were added.
3D CT and visualization data of the artifact AO8295 is published here: Michel, Cécile, Schroer, Christian, Olbrich, Stephan, Ehteram, Samaneh, & Beckert, Andreas. (2024). AO 8295 (X-Ray Tomography 3D data of an Enveloped Clay Tablet, Louvre Museum, Paris) [Data set]. http://doi.org/10.25592/uhhfdm.14776
The sources of our software EXAVIS42 is published here: Olbrich, Stephan, & Beckert, Andreas. (2024). EXAVIS42 – Efficient methods for creation, feature extraction, and interactive visualization of isosurfaces of 3D volume data [Software]. http://doi.org/10.25592/uhhfdm.1477
EXAVIS42 – Efficient methods for creation, feature extraction, and interactive visualization of isosurfaces of 3D volume data
No full textOur workflow of processing of 3D volume, geometric, and feature data consists of the following steps:
1. Preprocessing (filtering, resampling, denosing) of 3D volume data (here: result of CT)
2. Octree-based, compressed representation of isosurface and per-vertex data (EXA file format)
3. Triangulation of isosurface, implementing a manifold dual marching cube algorithm
4. Postprocessing (smoothing) and feature extraction of 3D polygon data (here: isosurface)
5. Interactive 3D visualization of isosurface and feature data (option: stereoscopic rendering)
All methods are implemented in C, taking advantage of multi-core parallelization in OpenMP, and applying OpenGL4 for 3D rendering purposes. GTK3 is used for abstraction of the user interface. The modules are tested in Linux (Ubuntu) and Windows environments (MSYS2 and MS Visual Studio).
An application example and data set is published here: Michel, Cécile, Schroer, Christian, Olbrich, Stephan, Ehteram, Samaneh, & Beckert, Andreas. (2024). AO 8295 (X-Ray Tomography 3D data of an Enveloped Clay Tablet, Louvre Museum, Paris) [Data set]. http://doi.org/10.25592/uhhfdm.14776
An video animation generated by EXAVIS42 is published here: Olbrich, Stephan, & Beckert, Andreas. (2024). Non-invasive, virtual unpacking of enclosed cuneiform - 3D reconstruction and visualization of clay tablets based on data acquired by portable micro-CT scanner. http://doi.org/10.25592/uhhfdm.14772
Our work will be published here: Olbrich, S., Beckert, A., Michel, C., Schroer, C., Ehteram, S., Schropp, A., Paetzold, P.: Efficient Analysis and Visualization of High-Resolution Computed Tomography Data for the Exploration of Enclosed Cuneiform Tablets. LDAV 2024 – 14th IEEE Symposium on Large Data Analysis and Visualization, October 13 – 18, 2024, St. Pete Beach, Florida (accepted)
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Non-invasive, virtual unpacking of enclosed cuneiform - 3D reconstruction and visualization of clay tablets based on data acquired by portable micro-CT scanner
No full textIn this video animation we visualize the reconstruction of an enclosed cuneiform tablet (Louvre Museum, collection no. AO8295, 19th century BC, showing a loan contract, 5.9 cm x 6.1 cm x 2.1 cm) and the envelope. The surface reconstruction, feature analysis, segmentation, and visualization was performed by "EXAVIS42" - which was developed by the author, as part of the project - from high-resolution volume data (38 µm voxel size), acquired by the portable micro-CT scanner "ENCI" - constructed as part of the project - at the collection of the Louvre Museum (Paris). The cuneiform signs are emphasized by a diffuse lighting model, combined with curvature-oriented highlighting and darkening, and shadowing by precalculated ambient occlusion, implementing an optimized function for weighting orientations of rays and their distances of crossed surfaces. The video clip was exported from "EXAVIS42" as a sequence of 4.850 anti-aliased images in 1920x1080 resolution (50 frames per second), off-screen rendered in OpenGL, by taking advantage of key frame animation, interpolating camera positions and orientations, as well as numerous visualization parameters
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