1,720,975 research outputs found
Projektvorstellung: Rekonstruktion der Glazialgeschichte im südlichen Hochland von Äthiopien
No full textGlobale Klima- und Gletscherveränderungen im Pleistozän und Holozän
No full textIn den vergangenen 2,6 Mio. Jahren des Pleistozäns und Holozäns erlebte die Erde eine Fülle von teils drastischen Klima- und Umweltveränderungen, die sich sehr deutlich in Änderungen der Kryosphäre, mit dem Auf- und Abbau von Gebirgsgletschern und kontinentalen Inlandeismassen, widerspiegeln. Mit vertikalen Verschiebungen von Höhenstufen reagierten vor allem Hochgebirge sehr sensitiv auf diese Veränderungen. Diese komplexe Entwicklung ist durch die Analyse von z.B. Gletscherschwankungen, Eisbohrkernen, marinen Bohrkernen, Pollen, Seesedimenten und Lössablagerungen mit Verwitterungshorizonten (Paläoböden) bekannt
Living the high life: the early arrival of hunter-gatherers in the glaciated Ethiopian Highlands
Full text linkHigh mountains around the globe have long been thought to represent pristine ecosystems that have been reshaped by humans quite late in the earth's history. The recent discovery of a 47-31 thousand-year-old residential site at 3,500 m in the Ethiopian Highlands contradicts this view and highlights the early expansion of Middle Stone Age hunter-gatherers into the cold and glaciated mountains
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
A low-cost and open-source approach for supraglacial debris thickness mapping using UAV-based infrared thermography
Full text linkAdditional code and data for the discussion paper by Jérôme Messmer and Alexander R. Groos entitled "A low-cost and open-source approach for supraglacial debris thickness mapping using UAV-based infrared thermography"
Correspondence: Alexander R. Groos ([email protected])
The repository contains
(1) visual and thermal UAV images, in situ measurements, visual and raw thermal orthophotos, and surface temperature and debris thickness maps from the Kanderfirn in the Swiss Alps
(2) a QGIS project with all datasets (coordinate reference system: WGS 84 / UTM zone 32 N; EPSG code: 32632)
(3) an open-source pipeline for the processing of thermal imagery and the modelling of supraglacial debris thicknesses
Description of sub-folders:
- debris_mask
-- kanderfirn_debrismask_2021-09-28.gpkg # debris mask for the surveyed debris-covered area on the Kanderfirn
-- kanderfirn_icesnowmask_2021-09-28.gpkg # ice-snow mask for the surveyed debris-covered area on the Kanderfirn
- debris_thickness:
-- kanderfirn_hd_diff_2021-09-28_emp-seb.tif #
-- kanderfirn_hd_empirical_2021-09-28.tif # simulated debris thickness (in meter) using the empirical model
-- kanderfirn_hd_global_rounce_et_al._2021.tif # global debris thickness (in meter) dataset of Rounce et al. 2021 (https://doi.org/10.1029/2020GL091311)
-- kanderfirn_hd_k0.5_2021-09-28.tif # simulated debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 0.5 W m -1 K -1
-- kanderfirn_hd_k0.6_2021-09-28.tif # simulated debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 0.6 W m -1 K -1
-- kanderfirn_hd_k0.7_2021-09-28.tif # simulated debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 0.7 W m -1 K -1
-- kanderfirn_hd_k0.8_2021-09-28.tif # simulated debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 0.8 W m -1 K -1
-- kanderfirn_hd_k0.9_2021-09-28.tif # simulated debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 0.9 W m -1 K -1
-- kanderfirn_hd_k1.0_2021-09-28.tif # simulated debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 1.0 W m -1 K -1
-- kanderfirn_hd_k1.1_2021-09-28.tif # simulated debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 1.1 W m -1 K -1
-- kanderfirn_hd_k1.2_2021-09-28.tif # simulated debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 1.2 W m -1 K -1
-- kanderfirn_hd_k1.3_2021-09-28.tif # simulated debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 1.3 W m -1 K -1
-- kanderfirn_hd_k1.4_2021-09-28.tif # simulated debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 1.4 W m -1 K -1
-- kanderfirn_hd_k1.5_2021-09-28.tif # simulated debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 1.5 W m -1 K -1
-- kanderfirn_hd_measured_2021-09-28.csv # table with the in-situ debris thickness measurements
- dsm:
-- kanderfirn_dsm_2021-09-28.tif # digital surface model of the surveyed debris-covered area on the Kanderfirn
- exif_data:
-- kanderfirn_thermal_images_exif_data_2021-09-28.csv # positional information of the thermal UAV images from 2021-09-28
-- kanderfirn_visual_images_exif_data_2021-09-28.csv # positional information of the visual UAV images from 2021-09-28
- gcp_files:
-- kanderfirn_gcp_list_thermal_2021-09-28.txt # ground control file for the processing of the thermal images with OpenDroneMap
-- kanderfirn_gcp_list_visual_2021-09-28.txt # ground control file for the processing of the visual images with OpenDroneMap
- orthophotos:
-- kanderfirn_orthophoto_raw_thermal_2021-09-28_odm.tif # raw thermal orthophoto created with OpenDroneMap using the raw thermal UAV images
-- kanderfirn_orthophoto_raw_thermal_2021-09-28_pix4d.tif # raw thermal orthophoto created with Pix4Dmapper using the raw thermal UAV images
-- kanderfirn_orthophoto_visual_2021-09-28.tif # visual orthophoto of the surveyed debris-covered area on the Kanderfirn
- R_scripts:
-- copy_metadata.R # script to copy exif metadata from radiometric jpegs and visual images (with gps data) to raw thermal images (without any metadata)
-- jpg2raw.R # script to convert radiometric jpegs into 16 bit raw thermal images using exiftool
-- raw2temp.R # script to compute distributed surface temperatures from a raw thermal orthophoto
-- temp2hd.R # script to derive debris thickness from mapped surface temperature using the theoretical model of Evatt et al. 2015 (https://doi.org/10.3189/2015JoG14J235)
- study_area:
-- kanderfirn_perimeter_2021-09-14.gpkg # perimeter of the Kanderfirn in 2021
-- kanderfirn_studyarea_2021-09-28.gpkg # outline of the study area on the Kanderfirn
- surface_temperature:
-- kanderfirn_ts_diff_e0.95_2021-09-28_pix4d-odm.tif # difference between the OpenDroneMap and Pix4Dmapper surface temperature map (in °C)
-- kanderfirn_ts_e0.95_2021-09-28_odm.tif # debris surface temperatures in °C (thermal emissivity = 0.95) calculated from the raw thermal orthophoto created with OpenDroneMap
-- kanderfirn_ts_e0.95_2021-09-28_pix4d.tif # debris surface temperatures in °C (thermal emissivity = 0.95) calculated from the raw thermal orthophoto created with Pix4Dmapper
-- kanderfirn_ts_e0.97_2021-09-28_odm.tif # ice/snow surface temperatures in °C (thermal emissivity = 0.97) calculated from the raw thermal orthophoto created with OpenDroneMap
-- kanderfirn_ts_e0.97_2021-09-28_pix4d.tif # ice/snow surface temperatures in °C (thermal emissivity = 0.97) calculated from the raw thermal orthophoto created with Pix4Dmapper
-- kanderfirn_ts_measured_2021-09-28.csv # in-situ temperature measurements in °C
-- kanderfirn_ts_val_e0.97_2021-09-28_odm.tif # ice/snow surface temperatures (°C) in the validation area calculated from the raw thermal orthophoto created with OpenDroneMap
-- kanderfirn_ts_val_e0.97_2021-09-28_pix4d.tif # ice/snow surface temperatures (°C) in the validation area calculated from the raw thermal orthophoto created with Pix4Dmapper
- thermal_images:
-- radiometric # selection of radiometric thermal images captured with the FLIR Vue Pro R 640 during the two UAV surveys (2021-09-28)
-- raw_data # raw data extracted with the Exiftool from the radiometric thermal images
- visual images:
-- *.JPG # selection of visual images captured with the internal camera of the Mavic Pro during the two UA
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
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