1,720,972 research outputs found
Seismic data collected at the Tinguatón volcano (Lanzarote, Canary Islands) during the European Space Agency (ESA) testing campaign PANGAEA-X 2018
No full textThis dataset contains the seismic data collected between 19 and 21 November 2018 at the Tinguatón volcanic region (Los Volcanes Natural Park, Geoparc of Lanzarote, Canary Islands, Fig. 1), within the A1TRAP experiment which formed part of the Analog-1 geology and science support activity (Rossi et al., 2019). Analog 1 was part of a larger European Space Agency (ESA) testing campaign PANGAEA-X 2018 (Bessone et al., 2018), aimed at integrating astronaut training-data collection, documentation, analogue field geology procedures with remote sensing and in situ geophysical methods.
Single-station, free-field ambient seismic noise data were collected along two orthogonal profiles: Traverse A, crossing the Tinguatón volcano, and Traverse B passing alongside it (Fig. 1c). Traverse A is ESE-WNW oriented and aligned to the regional fault (as well as along the fissure vent inside the volcano crater), and consists of 12 stations (P1-P12), approximately 50 m apart, with a total profile length of 620 m. Traverse B is NNW-SSE oriented and orthogonal to the regional fault strike, and consists of 9 stations (P13-P20), approximately 50 m apart, with a total profile length of 390 m.
Data were collected using a Tromino® model ENGY digital tromograph (Micromed, 2011). This is an ultralight all-in-one device, using a compact 3-directional, 24-bit digital seismometer developed by MoHo s.r.l. (1 dm3 volume and 1 kg weight), including both sensors and the data acquisition system, and works at frequencies down to 0.3 Hz. This seismograph is equipped with three orthogonal electrodynamic sensors (velocimeters), powered by two 1.5 V AA batteries. It includes an internal GPS antenna and does not have any external cables.
The seismometer’s major axis was aligned to the edge of the Tinguatón volcano at the interception of Traverse A, the main topographic feature, during all the measurements. Good ground coupling on scoria deposits or highly weathered basalt was obtained by using three, 6 cm-long metal spikes screwed into the base of the unit. The seismometer was levelled. Each seismic noise acquisition involved a 16-minute trace length with a 1024 Hz sampling rate, in accordance with the recommendations from SESAME Project (Bard et al., 2004).
Four MASW (Multichannel Analysis of Surface Waves) active seismic surveys (A3_5, A7, A8_10, A18_19) were undertaken along the two profiles (Fig. 1c) to acquire the shear wave velocity of the shallow layer which was later to be used to constrain the H/V inversion. These surveys were carried out using the same equipment, along with a wireless trigger by MoHo s.r.l., and a heavy metal plate struck with a 5 kg hammer for the generation of compressional waves. A redundant test which involved ground energization provided by an astronaut (Matthias Maurer) jumping (Fig. 1c) did not provide satisfactory results in term of signal clarity. The seismometer was kept fixed on the ground while shot points were moved at increasing distances involving a 5 m minimum offset and 1 m spacing for the first 11 shots and 5 m spacing for subsequent shots for total profile lengths ranging between 50 m and 100 m (Fig. 1c). Each MASW acquisition involved a 3 s trace window with a 512 Hz sampling rate.
The data are presented in ASCII format files. The recordings of each channel were saved all together in the same file. Information about each file was printed on the header of the same file.
Acknowledgements
The authors are grateful to ESA and all PANGAEA-X 2018 staff, particularly Loredana Bessone and Matthias Maurer for their participation in data collection during some of the experiments and to the MilesBeyond Team, particularly Francesco Maria Sauro for his logistical support. We also thank MoHo s.r.l., particularly Jeremy Magnon, for providing instrumental support.
References
Bessone, L., et al., 2018, Testing technologies and operational concepts for field geology exploration of the
Moon and beyond: the ESA PANGAEA-X campaign, Geophysical Research Abstract, #EGU2018-4013.
Micromed, 2011. Dati tecnici Tromino e download pacchetto software Grilla. Available online from the
website http://www.tromino.it.
Bard, P., Duval, A., Koehler, A., Rao, S., 2004, Guidelines for the Implementation of the H/V Spectral Ratio
Technique on Ambient Vibrations Measurements, Processing and Interpretation. SESAME H/V User Guidelines., pp. 1–62. Available online: http://sesame.geopsy.org/SES_Reports.htm.
Rossi, A.P., et al., 2019, Morphometry and trafficability of planetary analogue terrains based on very high
resolution remote sensing imagery, Geophysical Research Abstract, #EGU2019-17614.</p
Combining Behavior Trees and State Machines for Mission Planning in Autonomous Flight
No full textThis bachelor’s thesis explores a novel approach to mission planning in autonomous flight. In the ever-evolving field of autonomous aerial vehicles, efficient and adaptable mission planning is crucial for the safe and effective operation of the aerial system.
Traditionally, mission planning has relied on many methods including behavior trees and state machines to guide the decision-making process of autonomous drones. Behavior trees offer flexibility in representing complex behaviors but can be challenging to manage when multiple behaviors interact. On the other hand, state machines provide clear transitions between states, simplifying control logic, but may struggle to handle intricate and dynamic missions systematically.
This research proposes a three-layer system, the top layer being a behavior tree responsible for following the overall mission objectives and higher-level decision-making. The second layer is a state machine responsible for ensuring the system’s safety (for example, ensuring that the emergency state can always be reached). The last layer involves individual behavior trees for each of the states. These layers are meant to interact with each other, providing vital information such as the current state and state transitions to be executed. This system intends to create a more versatile and robust mission planning system. By integrating the two concepts, this thesis aims to combine the benefits of each approach while trying to overcome their individual limitations. The resulting hybrid framework intends to offer increased adaptability, reliable decision-making, and enhanced autonomy during flight.
With continuous growth in the field of autonomous aviation, the outcomes of this research aim to contribute meaningfully to the decision-making algorithms for use in autonomous systems, enhancing their versatility and adaptability in various scenarios. By combining existing technologies, this study seeks to pave the way for more efficient and reactive autonomous aerial operations, with applications extending to various domains, including surveillance, delivery, and transportation
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
Multi-modale 3D-Kartierung - Kombination von 3D-Punktwolken mit Thermo- und Farbinformation
No full textImagine a technology that automatically creates a full 3D thermal model of an environment and detects temperature peaks in it. For better orientation in the model it is enhanced with color information. The current state of the art for analyzing temperature related issues is thermal imaging. It is relevant for energy efficiency but also for securing important infrastructure such as power supplies and temperature regulation systems. Monitoring and analysis of the data for a large building is tedious as stable conditions need to be guaranteed for several hours and detailed notes about the pose and the environment conditions for each image must be taken. For some applications repeated measurements are necessary to monitor changes over time. The analysis of the scene is only possible through expertise and experience.
This thesis proposes a robotic system that creates a full 3D model of the environment with color and thermal information by combining thermal imaging with the technology of terrestrial laser scanning. The addition of a color camera facilitates the interpretation of the data and allows for other application areas. The data from all sensors collected at different positions is joined in one common reference frame using calibration and scan matching. The first part of the thesis deals with 3D point cloud processing with the emphasis on accessing point cloud data efficiently, detecting planar structures in the data and registering multiple point clouds into one common coordinate system. The second part covers the autonomous exploration and data acquisition with a mobile robot with the objective to minimize the unseen area in 3D space. Furthermore, the combination of different modalities, color images, thermal images and point cloud data through calibration is elaborated. The last part presents applications for the the collected data. Among these are methods to detect the structure of building interiors for reconstruction purposes and subsequent detection and classification of windows. A system to project the gathered thermal information back into the scene is presented as well as methods to improve the color information and to join separately acquired point clouds and photo series.
A full multi-modal 3D model contains all the relevant geometric information about the recorded scene and enables an expert to fully analyze it off-site. The technology clears the path for automatically detecting points of interest thereby helping the expert to analyze the heat flow as well as localize and identify heat leaks. The concept is modular and neither limited to achieving energy efficiency nor restricted to the use in combination with a mobile platform. It also finds its application in fields such as archaeology and geology and can be extended by further sensors.Man stelle sich eine Technologie vor, die automatisch ein vollständiges
3D-Thermographiemodell einer Umgebung generiert und Temperaturspitzen darin
erkennt. Zur besseren Orientierung innerhalb des Modells ist dieses mit
Farbinformationen erweitert. In der Analyse temperaturrelevanter Fragestellungen
sind Thermalbilder der Stand der Technik. Darunter fallen Energieeffizienz und
die Sicherung wichtiger Infrastruktur, wie Energieversorgung und Systeme zur
Temperaturregulierung. Die Überwachung und anschließende Analyse der Daten eines
großen Gebäudes ist aufwändig, da über mehrere Stunden stabile Bedingungen
garantiert und detaillierte Aufzeichnungen über die Aufnahmeposen und die
Umgebungsverhältnisse für jedes Wärmebild erstellt werden müssen. Einige
Anwendungen erfordern wiederholte Messungen, um Veränderungen über die Zeit zu
beobachten. Eine Analyse der Szene ist nur mit Erfahrung und Expertise möglich.
Diese Arbeit stellt ein Robotersystem vor, das durch Kombination von
Thermographie mit terrestrischem Laserscanning ein vollständiges 3D Modell der
Umgebung mit Farb- und Temperaturinformationen erstellt. Die ergänzende
Farbkamera vereinfacht die Interpretation der Daten und eröffnet weitere
Anwendungsfelder. Die an unterschiedlichen Positionen aufgenommenen Daten aller
Sensoren werden durch Kalibrierung und Scanmatching in einem gemeinsamen
Bezugssystem zusammengefügt. Der erste Teil der Arbeit behandelt
3D-Punktwolkenverarbeitung mit Schwerpunkt auf effizientem Punktzugriff,
Erkennung planarer Strukturen und Registrierung mehrerer Punktwolken in einem
gemeinsamen Koordinatensystem. Der zweite Teil beschreibt die autonome Erkundung
und Datenakquise mit einem mobilen Roboter, mit dem Ziel, die bisher nicht
erfassten Bereiche im 3D-Raum zu minimieren. Des Weiteren wird die Kombination
verschiedener Modalitäten, Farbbilder, Thermalbilder und Punktwolken durch
Kalibrierung ausgearbeitet. Den abschließenden Teil stellen Anwendungsszenarien
für die gesammelten Daten dar, darunter Methoden zur Erkennung der
Innenraumstruktur für die Rekonstruktion von Gebäuden und der anschließenden
Erkennung und Klassifizierung von Fenstern. Ein System zur Rückprojektion der
gesammelten Thermalinformation in die Umgebung wird ebenso vorgestellt wie
Methoden zur Verbesserung der Farbinformationen und zum Zusammenfügen separat
aufgenommener Punktwolken und Fotoreihen.
Ein vollständiges multi-modales 3D Modell enthält alle relevanten geometrischen
Informationen der aufgenommenen Szene und ermöglicht einem Experten, diese
standortunabhängig zu analysieren. Diese Technologie ebnet den Weg für die
automatische Erkennung relevanter Bereiche und für die Analyse des Wärmeflusses
und vereinfacht somit die Lokalisierung und Identifikation von Wärmelecks für
den Experten. Das vorgestellte modulare Konzept ist weder auf den Anwendungsfall
Energieeffizienz beschränkt noch auf die Verwendung einer mobilen Plattform
angewiesen. Es ist beispielsweise auch in Feldern wie der Archäologie und
Geologie einsetzbar und kann durch zusätzliche Sensoren erweitert werden
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
- …
