1,720,961 research outputs found
Unmanned Aerial Vehicle (UAV) And Ground-Based Structure From Motion Photogrammetry For Stratigraphic and Structural Analysis
Get PDFStructure from Motion (SfM) is a recently developed tool for advanced topographic surveys.
This technique may be applied either from airborne or ground-based platforms. This new
innovative approach has become a more accessible, cost-effective, and practical means of
produce high quality 3D outcrop and geological models, which were traditional produced
using expensive and highly technical laser scanning technology. This work illustrates four
case studies in which aerial-based SfM photogrammetry has been used as a complementary
data acquisition tool, in order to enhance and calibrate other data sets, and in an effort to
build a more complete interpretation of stratigraphic and structural outcrop features. The
results of these studies apply directly to the fields of sedimentology/stratigraphy, field
mapping, basin analysis, and reservoir characterization. Furthermore, these studies apply this
technique to geological aspects ranging in scale from millimeter variations of fracture surface
topography, to centimeter-scale sedimentary structures, to decameter scale outcrop
geometries
3D PHOTOGRAMMETRY AS A TOOL FOR CREATING VIRTUAL OUTCROPS AND BUILDING VIRTUAL FIELD EXPERIENCES FOR GEOSCIENCE EDUCATION
No full textGeology field studies are fundamental experiences in geoscience education, providing students the opportunity to see real world examples which reinforce concepts learned in the classroom. However, due to logistics, cost restraints and other factors, field experiences are typically limited to the geographic area surrounding the class. We present a collection of 3D virtual outcrop models from various locations including the US, Iceland, Ireland, and Italy and a simple methodology for creating 3D virtual outcrops using structure from motion photogrammetry. These interactive models can provide students a unique opportunity to remotely visit numerous instructive geologic sites. Virtual outcrops can be a valuable resource for classroom-based activities and combined into educationally-themed virtual field experiences to support various learning goals. Our virtual outcrops can be embedded in web pages or as objects in Google Earth. Users, including those without sight, may even download and render the models in solid form using a 3D printer. These activities offer many of the same educational benefits as traditional field experiences allowing student participants the ability to remotely visit instructive geologic sites from around the world.
The Mid-Atlantic Geo Image Collection (M.A.G.I.C.) has been working to create a massive digital repository of digital geologic material intended for outreach, education and research. Our expansive collection was founded on a suite of ~1400 GigaPan images, but now includes a diverse array of 3D models of outcrops and hand samples. These materials are free and available to everyone for educational or research purposes, including training pre-service teachers. 3D hand samples are created by taking a series of static photos from multiple angles of the sample, and stitched together using Agisoft PhotoScan software. After the model is created, it is then uploaded to the website Sketchfab.com. From there, people can view, download, and embed the models into a website or print with a 3D printer – all for free.
Support for this project comes from the Google Earth for On-site and Distance Education project (GEODE, NSF DUE 1323419)
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
USING UAV BASED PHOTOGRAMMETRY TO MAP STRATIGRAPHIC ARCHITECTURE IN SEDIMENTARY SYSTEMS
No full textTechnology relating to Unmanned Aerial Vehicles (UAVs), or drones, is rapidly becoming more accessible and available as a solution for obtaining geologic field data. UAV’s versatility, ease of use, and ability to obtain views and perspectives of outcrops otherwise unachievable make this approach useful for many different geoscience disciplines. Using Structure from Motion (SfM) photogrammetry methods, collections of overlapping UAV-based images can be compiled to form 3D digital surface models, which enables detailed inspection of outcrops and landscapes. These resulting 3D outcrop surface models can be manipulated and analyzed using various software packages, in order to extract quantitative geologic data such as bedding thickness, and orientations and geometries of lithological bodies. This study aims to illustrate how drone-based photogrammetry can be used to assess stratigraphic architecture at both the bed-scale and outcrop-scale in various sedimentary systems. We present a suite of digital outcrop sections from the upper Paleozoic strata exposed in the Appalachian Mountains in West Virginia and Apennine Mountains of Central Italy, which record different sedimentary environments, from deep water marine, shallow water marine, and fluvial systems.
The online digital version of these presented materials will be incorporated into a previous Virtual Field Trip Experience (Pitts 2015) covering the same area. These, along with other associated digital geologic resources are accessible to the public for educational or research purposes as part of the Google Earth for On-site and Distance Education project (GEODE, DUE 1323419)
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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
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