1,720,954 research outputs found
Analyse der Sedimentdynamik im Wildbach Lattenbach auf Basis digitaler Fernerkundung und Photogrammetrie
No full textMurgänge treten in alpinen Regionen häufig auf. Das Größe eines Ereignisses hängt nicht nur von den auslösenden Niederschlägen ab, sondern auch von den sedimentologischen Gegebenheiten des Einzugsgebietes. Diese sind in den meisten Fällen schlecht erfassbar. Eine genauere Kenntnis dieser würde jedoch die Risikobewertung verbessern. In dieser Masterarbeit wird die Sedimentdynamik in Zusammenhang mit Muren am Lattenbach näher untersucht. Das 5,3 km² große Einzugsgebiet des Lattenbachs liegt in Grins (Tirol, Österreich). Im Zuge der Fernerkundung, basierend auf Drohnenaufnahmen zu verschiedenen Zeitpunkten zwischen 2020 und 2022 und anschließender photogrammetrischer Auswertung, wurden insgesamt acht digitale Höhenmodelle (DHM) erstellt. Im Zuge der Auswertung wurden daraus elf digitale Differenzhöhenmodelle (DoD) erstellt. Mit den Differenzhöhenmodellen wurden geomorphologische Veränderungen im Gerinnebett des Lattenbachs lokalisiert und quantifiziert. Es wurde ein Zusammenhang zwischen tiefen Massenbewegungen und der Sedimentverfügbarkeit im Gerinnebett mit anschließendem Transport durch Murgänge hergestellt. Zusätzlich wurde eine 20-jährige Niederschlagsdatenreihe von INCA-Daten analysiert und eine Intensitäts-Dauer-Kurve (ID-Schwelle) als Schwelle für Murgänge im Einzugsgebiet definiert. Die Ergebnisse der DoD zeigen, dass in Perioden mit Murgängen mehr Erosion und in Perioden ohne Murgänge mehr Deposition im Gerinne auftritt. Es wurde auch festgestellt, dass Erosion und Geschiebe während eines Ereignisses signifikant mit der Intensität der Niederschläge zusammenhängen. Die Ergebnisse dieser Arbeit sollen zeigen, dass eine Gefahrenabschätzung in steilen Wildbacheinzugsgebieten mit Hilfe der digitalen Fernerkundung möglich ist. Es soll auch gezeigt werden, dass die Daten für eine umfassende Beurteilung sehr präzise und genau sein müssen.Debris flows occur frequent in alpine regions. They can transport large quantities of sediment from the catchment area to the settlement area during long and/or intensive precipitation events. The magnitude of an event depends not only on the precipitation that triggers it, but also on the sedimentological conditions of the catchment area. The knowledge of potential event magnitudes from independent metrics of catchment characteristics would improve the risk assessment. In this master thesis the sediment dynamics in connection with debris flows are investigated for the Lattenbach catchment, Tyrol. In the course of remote sensing based on drone (UAV) recordings at various times between 2020 and 2022 and subsequent photogrammetric evaluation, a total of eight digital elevation models (DEM) were created. After the evaluation, 11 digital difference elevation models (DoD) had been created. The differential elevation models were used to localize and quantify geomorphological changes in the channel bed of the Lattenbach. A correlation between deep mass movements and sediment availability in the channel bed with subsequent transport as a result of debris flows was established. In addition, a 20-year precipitation data series of INCA data was analyzed, and an intensity duration curve (ID threshold) was defined as a threshold for debris flows in the catchment area. The results of the DoD show that more erosion occurs in the channel bed during periods with debris flows and more deposition during periods without debris flows. It was also found that erosion and bed load during an event are significantly related to the intensity of precipitation. The results of this work are intended to show that hazard assessment in steep torrent catchment areas is possible with the aid of digital remote sensing. It could also be shown that the data must be very precise and accurate for a comprehensive assessment.verfasst von Elias HackhoferMasterarbeit Universität für Bodenkultur Wien 2024Mit englischer Zusammenfassun
Analyse der Sedimentdynamik im Wildbach Lattenbach auf Basis digitaler Fernerkundung und Photogrammetrie
No full textMurgänge treten in alpinen Regionen häufig auf. Das Größe eines Ereignisses hängt nicht nur von den auslösenden Niederschlägen ab, sondern auch von den sedimentologischen Gegebenheiten des Einzugsgebietes. Diese sind in den meisten Fällen schlecht erfassbar. Eine genauere Kenntnis dieser würde jedoch die Risikobewertung verbessern. In dieser Masterarbeit wird die Sedimentdynamik in Zusammenhang mit Muren am Lattenbach näher untersucht. Das 5,3 km² große Einzugsgebiet des Lattenbachs liegt in Grins (Tirol, Österreich). Im Zuge der Fernerkundung, basierend auf Drohnenaufnahmen zu verschiedenen Zeitpunkten zwischen 2020 und 2022 und anschließender photogrammetrischer Auswertung, wurden insgesamt acht digitale Höhenmodelle (DHM) erstellt. Im Zuge der Auswertung wurden daraus elf digitale Differenzhöhenmodelle (DoD) erstellt. Mit den Differenzhöhenmodellen wurden geomorphologische Veränderungen im Gerinnebett des Lattenbachs lokalisiert und quantifiziert. Es wurde ein Zusammenhang zwischen tiefen Massenbewegungen und der Sedimentverfügbarkeit im Gerinnebett mit anschließendem Transport durch Murgänge hergestellt. Zusätzlich wurde eine 20-jährige Niederschlagsdatenreihe von INCA-Daten analysiert und eine Intensitäts-Dauer-Kurve (ID-Schwelle) als Schwelle für Murgänge im Einzugsgebiet definiert. Die Ergebnisse der DoD zeigen, dass in Perioden mit Murgängen mehr Erosion und in Perioden ohne Murgänge mehr Deposition im Gerinne auftritt. Es wurde auch festgestellt, dass Erosion und Geschiebe während eines Ereignisses signifikant mit der Intensität der Niederschläge zusammenhängen. Die Ergebnisse dieser Arbeit sollen zeigen, dass eine Gefahrenabschätzung in steilen Wildbacheinzugsgebieten mit Hilfe der digitalen Fernerkundung möglich ist. Es soll auch gezeigt werden, dass die Daten für eine umfassende Beurteilung sehr präzise und genau sein müssen.Debris flows occur frequent in alpine regions. They can transport large quantities of sediment from the catchment area to the settlement area during long and/or intensive precipitation events. The magnitude of an event depends not only on the precipitation that triggers it, but also on the sedimentological conditions of the catchment area. The knowledge of potential event magnitudes from independent metrics of catchment characteristics would improve the risk assessment. In this master thesis the sediment dynamics in connection with debris flows are investigated for the Lattenbach catchment, Tyrol. In the course of remote sensing based on drone (UAV) recordings at various times between 2020 and 2022 and subsequent photogrammetric evaluation, a total of eight digital elevation models (DEM) were created. After the evaluation, 11 digital difference elevation models (DoD) had been created. The differential elevation models were used to localize and quantify geomorphological changes in the channel bed of the Lattenbach. A correlation between deep mass movements and sediment availability in the channel bed with subsequent transport as a result of debris flows was established. In addition, a 20-year precipitation data series of INCA data was analyzed, and an intensity duration curve (ID threshold) was defined as a threshold for debris flows in the catchment area. The results of the DoD show that more erosion occurs in the channel bed during periods with debris flows and more deposition during periods without debris flows. It was also found that erosion and bed load during an event are significantly related to the intensity of precipitation. The results of this work are intended to show that hazard assessment in steep torrent catchment areas is possible with the aid of digital remote sensing. It could also be shown that the data must be very precise and accurate for a comprehensive assessment.verfasst von Elias HackhoferMasterarbeit Universität für Bodenkultur Wien 2024Mit englischer Zusammenfassun
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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