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1

Wirkungsunterschiede zwischen Digitalis purpurea und Digitalis lanata  

Microsoft Academic Search

Zusammenfassung Qualitative Unterschiede zwischen Digitalis purpurea und lanata bestehen:1.hinsichtlich der Latenzzeit, die am hypodynamen Straubschen Herzen für Digitalis purpurea 3–4 mal so lang ist, als für Digitalis lanata in gleicher Konzentration.2.wird die maximale Arbeitsleistung (Minutenvolumen) des durchströmten isolierten Froschherzens durch Digitalis lanata rascher erreicht als durch Digitalis purpurea gleicher Konzentration. Die therapeutische Phase dagegen dauert bei dem mit Digitalis purpurea

Fritz Heim

1936-01-01

2

Freud und Wittgenstein im Konflikt zwischen skularem Denken und Religion  

E-print Network

, den 25. Februar 2015, 18.15h-19.30h / Hauptgebäude / Raum 120 ,,Sigmund Freuds Atheismus wurde zumFreud und Wittgenstein im Konflikt zwischen säkularem Denken und Religion Symposion mit dem, säkularem Denken und Religion entfaltet hat. Er zeigt, wie Freud in seinem Leben und Denken auf sehr

Sola, Rolf Haenni

3

Große Nationalökonomen zwischen Glorifizierung und Verachtung - Einige Überlegungen zum Zusammenhang von Rezeptions-, Wissenschafts- und Wirtschafts  

Microsoft Academic Search

The aim of this contribution is to expound - on behalf of economics - on the field of tension characteristic for modern history of science between rationalist thought and social practice. More specific, it is the relevance of great political economists for economic policy that will be discussed from the point of view of history of science, eco- nomic history

John Maynard Keynes; Margrit Grabas

4

Variationsbreite, Variabilität und Beziehungen zwischen einigen Körper- und Gehörnmaßen beim Rehwild  

Microsoft Academic Search

Zusammenfassung An 2603 erlegten Rehen aus 4 Wildforschungsgebieten wurden Ermittlungen über die Variationsbreite, die Variabilität und die Zusammenhänge zwischen Körper- und Gehörnmaße durchgeführt. Die Variationsbreite ist bei den Böcken überwiegend höher als bei den Ricken. Die Variabilitätskoeffizienten der Körper- und Gehörnmaße nehmen mit dem Alter ab. Sie sind bei den Böcken höher als bei den Ricken. Der Variabilitätskoeffizient des Gehörnvolumens

C. Stubbe

1967-01-01

5

Spirographischer und atemmechanischer Wirkungsvergleich zwischen Orciprenalin (Alupent®) und dem Hydroxyphenyl-Derivat Th 1165  

Microsoft Academic Search

Zusammenfassung Die Wirksamkeit von Th1165, einem von Orciprenalin (Alupent®) abgeleiteten Beta-Adrenolyticum, wurde an Lungengesunden und Asthmatikern durch Kreislaufanalysen sowie spirographische und atemmechanische Funktionsprüfungen untersucht.

J. Hamm; H. Wüsthofen

1970-01-01

6

Beziehungen zwischen Körperbau und Lebensweise bei Blenniidae (Pisces) aus dem Roten Meer. I. Äußere morphologie  

Microsoft Academic Search

The external morphology of 5 species of salariin Blenniidae has been examined. Differences have been established between Salarias fasciatus living in the sublittoral, Antennablennius hypenetes, Istiblennius edentulus and I. flaviumbrinus inhabiting the eulittoral zone, and, especially, Alticus kirkii living on steep rocks of the supralittoral zone. The rays of the anal and (partly) pectoral fins terminate in little hooks; these

C. D. Zander

1972-01-01

7

Verhaltensunterschiede zwischen europäischen Formen der Silbermöwengruppe (Larus argentatus — cachinnans — fuscus)  

Microsoft Academic Search

Zusammenfassung Der Verhaltensvergleich zwischenL. a. argentatus bzw.a. argenteus (Nordsee),L. a. michahellis (Mittelmeer) undL. fuscus (Ostsee) erbrachte formale Differenzen bezüglich der wichtigsten Rufe und einiger Stellungen und Bewegungen. Danach scheintL. a. michahellis (geltend fürcachinnans) vonL. argentatus argenteus ebenso verschieden zu sein wieL. fuscus vonargenteus. Ähnlichkeiten in Rufformen und Bewegungen wurden zwischenL. a. michahellis undL. fuscus festgestellt. Beide gelbfüßigen Formen zeigen eine

Friedrich Goethe

1963-01-01

8

ASTER DEM performance  

USGS Publications Warehouse

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument onboard the National Aeronautics and Space Administration's Terra spacecraft has an along-track stereoscopic capability using its a near-infrared spectral band to acquire the stereo data. ASTER has two telescopes, one for nadir-viewing and another for backward-viewing, with a base-to-height ratio of 0.6. The spatial resolution is 15 m in the horizontal plane. Parameters such as the line-of-sight vectors and the pointing axis were adjusted during the initial operation period to generate Level-1 data products with a high-quality stereo system performance. The evaluation of the digital elevation model (DEM) data was carried out both by Japanese and U.S. science teams separately using different DEM generation software and reference databases. The vertical accuracy of the DEM data generated from the Level-1A data is 20 m with 95% confidence without ground control point (GCP) correction for individual scenes. Geolocation accuracy that is important for the DEM datasets is better than 50 m. This appears to be limited by the spacecraft position accuracy. In addition, a slight increase in accuracy is observed by using GCPs to generate the stereo data. ?? 2005 IEEE.

Fujisada, H.; Bailey, G.B.; Kelly, Glen G.; Hara, S.; Abrams, M.J.

2005-01-01

9

DEM Analysis Daniel Miller  

E-print Network

Programs for DEM Analysis by Daniel Miller 2002, 2003 Theory and Technology in Natural Sciences are a direct outgrowth of work sponsored by the Coastal Landscape Analysis and Modeling Study (http, vegetation, geomorphology, hydrology, and aquatic ecology, focusing on climatic disturbances, erosion

10

The Oracle of DEM  

NASA Astrophysics Data System (ADS)

The predictions of the famous Greek oracle of Delphi were just ambiguous enough to seem to convey information, yet the user was only seeing their own thoughts. Are there ways in which X-ray spectral analysis is like that oracle? It is shown using heuristic, generic response functions to mimic actual spectral inversion that the widely known ill conditioning, which makes formal inversion impossible in the presence of random noise, also makes a wide variety of different source distributions (DEMs) produce quite similar X-ray continua and resonance-line fluxes. Indeed, the sole robustly inferable attribute for a thermal, optically thin resonance-line spectrum with normal abundances in CIE is its average temperature. The shape of the DEM distribution, on the other hand, is not well constrained, and may actually depend more on the analysis method, no matter how sophisticated, than on the source plasma. The case is made that X-ray spectra can tell us average temperature, and metallicity, and absorbing column, but the main thing it cannot tell us is the main thing it is most often used to infer: the differential emission measure distribution.

Gayley, Kenneth

2013-06-01

11

E-Books im Spannungsfeld zwischen Verlagen, Aggregatoren, Bibliotheken und  

E-print Network

1 E-Books im Spannungsfeld zwischen Verlagen, Aggregatoren, Bibliotheken und Nutzern E-Book-Workshop für MPG-Bibliothekare 25. Oktober 2012 in Leipzig Dr. Arlette Piguet #12;2 Der E-Book-Markt #12;3 PUBLIZIEREN Fundamentale Veränderungen durch IuK- Technologien Neue Möglichkeiten: Google Book Search; Amazon

12

Hydrologic enforcement of lidar DEMs  

USGS Publications Warehouse

Hydrologic-enforcement (hydro-enforcement) of light detection and ranging (lidar)-derived digital elevation models (DEMs) modifies the elevations of artificial impediments (such as road fills or railroad grades) to simulate how man-made drainage structures such as culverts or bridges allow continuous downslope flow. Lidar-derived DEMs contain an extremely high level of topographic detail; thus, hydro-enforced lidar-derived DEMs are essential to the U.S. Geological Survey (USGS) for complex modeling of riverine flow. The USGS Coastal and Marine Geology Program (CMGP) is integrating hydro-enforced lidar-derived DEMs (land elevation) and lidar-derived bathymetry (water depth) to enhance storm surge modeling in vulnerable coastal zones.

Poppenga, Sandra K.; Worstell, Bruce B.; Danielson, Jeffrey J.; Brock, John C.; Evans, Gayla A.; Heidemann, H. Karl

2014-01-01

13

Functional performance in community-dwelling and institutionalized elderly women  

Microsoft Academic Search

\\u000a Zusammenfassung  ZIELE: Der hohe Stellenwert körperlicher Aktivität für die Gesundheit und Mobilität im höheren Alter gilt als hinreichend\\u000a belegt. Aktuelle Studien lassen einen Zusammenhang zwischen dem Lebensumfeld und dem körperlichen Aktivitätsniveau älterer\\u000a Menschen vermuten. In der vorliegenden Untersuchung wurden daher die muskuläre Leistungsfähigkeit der oberen Extremität, die\\u000a Gleichgewichtsfähigkeit und Reaktionszeit von selbständigen und im Heim lebenden Seniorinnen untersucht. METHODEN: Insgesamt\\u000a 31

Robert Csapo; Christian Gormasz; Ramon Baron

2009-01-01

14

Letale Intoxikationen mit Antidepressiva und NeuroleptikaAnalyse im Zusammenhang mit den Verordnungen in Wien von 1991 bis 1997  

Microsoft Academic Search

Zusammenfassung  \\u000a Wegen des zunehmenden Einsatzes der selektiven Serotoninwiederaufnahmehemmer (SSRI) verdoppelte sich die Zahl der verordneten\\u000a Antidepressiva (AD) in Wien zwischen 1991 und 1997. Gleichzeitig wurden am Institut fr Gerichtliche Medizin der Universitt\\u000a Wien 164 fatale Intoxikationen mit AD durch Autopsien und chemische Analysen nachgewiesen. Die von uns berechneten fatalen\\u000a Toxizittsindizes (f-Indizes) sagen aus, wie viele letale Intoxikationen es pro einer

R. Frey; D. Schreinzer; T. Stimpfl; W. Vycudilik; A. Berzlanovich; S. Kasper

2002-01-01

15

Einleitung Das Modell von Keller und Segel Erweiterungen des Models von Keller und Segel Zusammenhang Populations-und Zellbetrachtung Literatur Bakterielle Musterbildung, Chemotaxis  

E-print Network

Einleitung Das Modell von Keller und Segel Erweiterungen des Models von Keller und Segel;Einleitung Das Modell von Keller und Segel Erweiterungen des Models von Keller und Segel Zusammenhang Populations- und Zellbetrachtung Literatur Inhalt 1 Einleitung Das Experiment von Adler 2 / 48 #12;Einleitung

Münster, Westfälische Wilhelms-Universität

16

Patho-topographische Beziehungen zwischen der Steigbügelfußplatte und den Endolymphräumen  

Microsoft Academic Search

Zusammenfassung Bei einer Ektasie des Endolymphschlauches kommt - wie auf histologischen Schnittpräparaten gezeigt werden konnte - der Sacculus von medial her der Steigbügelfußplatte sehr nahe. In manchen Fällen legt er sich ihr sogar flächenhaft an. Auch die Reißnersche Membran tritt dann unter Umständen in noch engeren Kontakt mit dem unteren Rand des ovalen Fensters als es schon der Norm entspricht.

E. Lehnhardt

1964-01-01

17

Wiederbeginn nach dem Zweiten Weltkrieg  

NASA Astrophysics Data System (ADS)

Dieses Kapitel schildert zunächst die Ausgangslage für die Statistik in Deutschland nach dem Zweiten Weltkrieg: Der statistische Dienst in den Besatzungszonen musste teilweise erst aufgebaut und der statistische Unterricht an den Hochschulen wieder in Gang gebracht werden. In dieser Lage ergriff der Präsident des Bayerischen Statistischen Landesamtes, Karl Wagner, tatkräftig unterstützt von Gerhard Fürst, dem späteren Präsidenten des Statistischen Bundesamtes, die Initiative zur Neugründung der Deutschen Statistischen Gesellschaft (DStatG). Die Gründungsversammlung 1948 im München wurde zu einem Meilenstein in der Geschichte der DStatG. Ziel war es, alle Statistiker zur Zusammenarbeit anzuregen, ihre Qualifikation an das internationale Niveau heranzuführen und die Anwendung neuerer statistischer Methoden in der Praxis zu fördern. Es folgten 24 Jahre fruchtbarer Arbeit unter Karl Wagner (1948-1960) und Gerhard Fürst (1960-1972). Der Beitrag skizziert die Statistischen Wochen, die Tätigkeit der Ausschüsse und die Veröffentlichungen in dieser Zeit.

Strecker, Heinrich; Bassenge-Strecker, Rosemarie

18

BLACK HAWK DOWN: FILM ZWISCHEN REFLEKTION UND KONSTRUKTION GESELLSCHAFTLICHER WIRKLICHKEIT  

Microsoft Academic Search

Zusammenfassung  Am Beispiel von Ridley Scotts Kriegsfilm Black Hawk Down (USA 2001) geht dieser Artikel der Frage nach, ob Film in erster Linie eine vorhergehende Wirklichkeit reflektiert, oder\\u000a ob er aktiv an deren Konstituierung Teil hat. Vor dem Hintergrund von Jan und Aleida Assmanns Theorie des kulturellen Gedächtnisses\\u000a und Douglas Kellners Begriff der Medienkultur wird aufgezeigt, wie Scotts Film eine bestimmte

Holger Pötzsch

2009-01-01

19

SRTM DEM and its application advances  

Microsoft Academic Search

The Shuttle Radar Topography Mission (SRTM) provides for the first time a near-global high-resolution digital elevation model (DEM) with great advantages of homogeneous quality and free availability. The last 10 years or so have seen rapid advances in the data processing and applications of SRTM DEM. From the perspective of SRTM, we present in this article a brief overview of

Liping Yang; Xingmin Meng; Xiaoqiang Zhang

2011-01-01

20

DEM Construction using DInSAR  

NASA Astrophysics Data System (ADS)

A digital elevation model (DEM) is a 3D visualization of a terrain surface. It can be used in various analytical studies such as topographic feature extraction, hydrology, geomorphology and landslides analysis etc. Uttrakhand region is affected with landslides, earthquake and flash flood phenomenon. Hence this study was focused on DEM generation using Differential SAR Interferometry (DINSAR) on ALOS PALSAR dataset. Two Pass DINSAR technique involves one interferometric pair in addition with an external DEM. The external DEM was used as a reference to reduce topographic errors. The data processing steps were image co-registration, interferogram generation, interferogram flattening (Differential Interferogram), interferogram filtering, coherence map, phase unwrapping, orbital refinement and re-flattening and DEM generation. Interferogram fringes observed in forest areas were due to temporal decorrelation and the fringes in mountain regions were obtained due to topography changes (may be due to landslides in rainy season). The range of elevation in generated DEM were 132 m to 2823 m and Root Mean Square Error (RMSE) error was 36.765159 m. The generated DEM was compared with ASTER DEM and variation in height was analyzed. Atmospheric effects were not removed due to geometrical and temporal decorrelation which affect the accuracy.

Mangla, R.; Kumar, S.

2014-11-01

21

Die Entwicklung von Zelle und Kern im Protonema von Funaria hygrometrica Sibth  

Microsoft Academic Search

Zusammenfassung 1.Die Entwicklung von Zelle und Kern in den Caulonemen vonFunaria hygrometrica Sibth. wurde untersucht.2.Ein Zusammenhang zwischen bestimmten Funktionen der Zelle und dem Kernzustand in verschiedenen Abschnitten konnte festgestellt werden. So besitzen die Spitzenzellen, auf die das Plasmawachstum beschränkt ist, einen großen, stark “vacuolisierten” Nucleolus. Die Zellen, in denen sich die Membran bräunt, zeigen eine meßbare Kernvergrößerung.3.Chromocentren werden erst in

Martin Bopp

1955-01-01

22

Über das Gehörorgan der Mormyriden  

Microsoft Academic Search

1.Im Gehörlabyrinth der Mormyriden findet sich eine große dünnwandige Blase, die einen Abkömmling der Schwimmblase darstellt, in engstem Zusammenhang mit dem Sacculus steht und von außen durch eine Knochenplatte abgedeckt wird.2.Zwischen Utriculus und Sacculus besteht keine Verbindung; Sacculus und Lagena hängen durch einen kurzen Kanal mit engem Lumen zusammen.3.Der Knochendeckel ist das Extrascapulare; er ist lose bindegewebig dicht über der

Elisabeth Stipeti?

1939-01-01

23

An assessment of TanDEM-X GlobalDEM over rural and urban areas  

NASA Astrophysics Data System (ADS)

Digital Elevation Model (DEM) is a key input for the development of risk management systems. Main limitation of the current available DEM is the low level of resolution. DEMs such as STRM 90m or ASTER are globally available free of charge, but offer limited use, for example, to flood modelers in most geographic areas. TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement), the first bistatic SAR can fulfil this gap. The mission objective is the generation of a consistent global digital elevation model with an unprecedented accuracy according to the HRTI-3 (High Resolution Terrain Information) specifications. The mission opens a new era in risk assessment. In the framework of ALTAMIRA INFORMATION research activities, the DIAPASON (Differential Interferometric Automated Process Applied to Survey Of Nature) processing chain has been successfully adapted to TanDEM-X CoSSC (Coregistered Slant Range Single Look Complex) data processing. In this study the capability of CoSSC data for DEM generation is investigated. Within the on-going FP7 RASOR project (Rapid Analysis and Spatialisation and Of Risk), the generated DEM are compared with Intermediate DEM derived from the TanDEM-X first global coverage. The results are presented and discussed.

Koudogbo, Fifamè N.; Duro, Javier; Huber, Martin; Rudari, Roberto; Eddy, Andrew; Lucas, Richard

2014-10-01

24

Autofahren zwischen Alltagsnutzung und Routinebruch: Bericht 1 der choice-Forschung  

Microsoft Academic Search

In dem Forschungsprojekt „cash car: Der Bedeutungswandel des Privat-Automobils zum Kernmodul eines integrierten Verkehrsdienstleisters“ wird ein sozialer Feldversuch realisiert, in dem zum einen die Akzeptanz einer konkreten neuen Verkehrsdienstleistung erprobt und zum anderen das Verkehrsverhalten generell unter veränderten Angebotsbedingungen untersucht werden können. Cash car ist ein full-service- Leasing-Angebot, das dem Kunden die Verfügbarkeit über ein Automobil gibt und zugleich die

Weert Canzler; Sassa Franke

2000-01-01

25

Segregation in Rapid Flows: Continuum and DEM  

E-print Network

Approaches Discrete Element Method (DEM): an equation of motion (Newton's law) is solved for each particle a single equation of motion for the particulate phase: particle phase is treated as a continuum dm m dt equation of motion for each particle phase) BUT, for more complex systems, however, the computational

Gruner, Daniel S.

26

Auf der Suche nach dem Unendlichen.  

NASA Astrophysics Data System (ADS)

This book is a German translation by C. Ascheron and J. Urbahn, of "The search for infinity: solving the mysteries of the universe", published in 1994. Diese Buch beschreibt anschaulich die Meilensteine, die der Mensch seit der Antike auf der Suche nach dem Unendlichen erreicht und hinter sich gelassen hat. Es enthält Kurzbiographien der wichtigsten Forscher, verständlich geschriebene Texte sowie Erläuterungen der entscheidenen Fachtermini.

Fraser, G.; Lillestøl, E.; Sellevåg, I.

27

Advanced interferometric SAR techniques with TanDEM-X  

Microsoft Academic Search

TanDEM-X is an innovative mission with a TerraSAR-X add-on satellite for high-resolution single-pass SAR interferometry. The TanDEM-X mission has the primary objective of generating a consistent, global DEM with an unprecedented accuracy according to the HRTI-3 specifications (2 m height accuracy, 12 m posting). Beyond that, TanDEM-X provides a configurable SAR interferometric platform for demonstrating new SAR techniques and applications.

Alberto Moreira; Gerhard Krieger; Hauke Fiedler; Irena Hajnsek; Marwan Younis; Manfred Zink; Marian Werner

2008-01-01

28

Neuroökonomie und Neuromarketing — Erkenntnisse der Gehirnforschung für die Gestaltung von Beziehungen zwischen Kunden und Unternehmen  

Microsoft Academic Search

Innerhalb der letzten Jahre hat die Beachtung von Ergebnissen der Neuroökonomie und des Neuromarketing sowohl in der Wissenschaft\\u000a als auch in der Praxis deutlich zugenommen. Im Rahmen der Neuroökonomie werden ökonomische Fragestellungen mit neurowissenschaftlichen Erkenntnissen und Methoden analysiert (vgl. Hain\\/ Kenning\\/\\u000a Lehmann-Waffenschmidt 2007). Der Schwerpunkt der Forschung liegt vor allem darauf, zu ergründen, wie im Gehirn zwischen Verhaltensalternativen\\u000a gewählt wird.

Christian Duchmann; Armin Töpfer

29

Cytochrom b-Sequenz-Vergleiche zwischen Wisent (Bison bison bonasus) und Hausrind (Bos primigenius f. taurus)  

Microsoft Academic Search

Vom Wisent (bison bison bonasus) wurde die Nukleotid-Sequenz des Cytochrom b-Gens bestimmt. Die erstellte Basenfolge und die daraus ermittelte Aminosäuren-Sequenz wurde mit den entsprechenden Sequenzen des Rindes aus der EMBL-Datenbank verglichen. Dabei wurden die Basen- bzw. die Aminosäurensubstitutionsraten sowie das Verhältnis von Transitionen zu Transversionen berechnet. Die Homologien zwischen den verglichenen Nukleotid- und Aminosäuren-Sequenzen von Wisent und Rind entsprachen den

Stefanie Zimmermann; R. Zehner; A. Herzog

1998-01-01

30

Quality assessment of TanDEM-X DEMs using airborne LiDAR, photogrammetry and ICESat elevation data  

NASA Astrophysics Data System (ADS)

TanDEM-X mission has been acquiring InSAR data to produce high resolution global DEM with greater vertical accuracy since 2010. In this study, TanDEM-X CoSSC data were processed to produce DEMs at 6 m spatial resolution for two test areas of India. The generated DEMs were compared with DEMs available from airborne LiDAR, photogrammetry, SRTM and ICESat elevation point data. The first test site is in Bihar state of India with almost flat terrain and sparse vegetation cover and the second test site is around Godavari river in Andhra Pradesh (A.P.) state of India with flat to moderate hilly terrain. The quality of the DEMs in these two test sites has been specified in terms of most widely used accuracy measures viz. mean, standard deviation, skew and RMSE. The TanDEM-X DEM over Bihar test area gives 5.0 m RMSE by taking airborne LiDAR data as reference. With ICESat elevation data available at 9000 point locations, RMSE of 5.9 m is obtained. Similarly, TanDEM-X DEM for Godavari area was compared with high resolution aerial photogrammetric DEM and SRTM DEM and found RMSE of 5.3 m and 7.5 m respectively. When compared with ICESat elevation data at several point location and also the same point locations of photogrammetric DEM and SRTM, the RMS errors are 4.1 m, 3.5 m and 4.3 m respectively. DEMs were also compared for open-pit coal mining area where elevation changes from -147 m to 189 m. X- and Y-profiles of all DEMs were also compared to see their trend and differences.

Rao, Y. S.; Deo, R.; Nalini, J.; Pillai, A. M.; Muralikrishnan, S.; Dadhwal, V. K.

2014-11-01

31

DEM Simulation of Continental Collision in Asia  

NASA Astrophysics Data System (ADS)

Indentation tectonics, a type of plate tectonic deformation due to a collision of a small continental block into a continent of larger size, causes complicated deformations around the boundary of the two continents. One typical example is the collision process of the Indian sub-continent to the Eurasian Plate, and a series of physical experiments explained the major tectonic features in the Eastern Asia excellently. This paper employed a numerical technique, the Discrete Element Method (DEM), to investigate the indentation tectonics and the results were compared with the experimental results. The overall geometry and progressive development of major fault systems associated with secondary basins showed similarity between the two techniques, whereas the secondary fault systems seen in the experiments were less developed in the simulation. Despite there still need further refinements in the technique, the DEM approach to the geological deformation can be a powerful tool to simulate fault related structures.

Yamada, Y.; Tanaka, A.; Matsuoka, T.

2002-12-01

32

Incorporating DEM uncertainty in coastal inundation mapping.  

PubMed

Coastal managers require reliable spatial data on the extent and timing of potential coastal inundation, particularly in a changing climate. Most sea level rise (SLR) vulnerability assessments are undertaken using the easily implemented bathtub approach, where areas adjacent to the sea and below a given elevation are mapped using a deterministic line dividing potentially inundated from dry areas. This method only requires elevation data usually in the form of a digital elevation model (DEM). However, inherent errors in the DEM and spatial analysis of the bathtub model propagate into the inundation mapping. The aim of this study was to assess the impacts of spatially variable and spatially correlated elevation errors in high-spatial resolution DEMs for mapping coastal inundation. Elevation errors were best modelled using regression-kriging. This geostatistical model takes the spatial correlation in elevation errors into account, which has a significant impact on analyses that include spatial interactions, such as inundation modelling. The spatial variability of elevation errors was partially explained by land cover and terrain variables. Elevation errors were simulated using sequential Gaussian simulation, a Monte Carlo probabilistic approach. 1,000 error simulations were added to the original DEM and reclassified using a hydrologically correct bathtub method. The probability of inundation to a scenario combining a 1 in 100 year storm event over a 1 m SLR was calculated by counting the proportion of times from the 1,000 simulations that a location was inundated. This probabilistic approach can be used in a risk-aversive decision making process by planning for scenarios with different probabilities of occurrence. For example, results showed that when considering a 1% probability exceedance, the inundated area was approximately 11% larger than mapped using the deterministic bathtub approach. The probabilistic approach provides visually intuitive maps that convey uncertainties inherent to spatial data and analysis. PMID:25250763

Leon, Javier X; Heuvelink, Gerard B M; Phinn, Stuart R

2014-01-01

33

Incorporating DEM Uncertainty in Coastal Inundation Mapping  

PubMed Central

Coastal managers require reliable spatial data on the extent and timing of potential coastal inundation, particularly in a changing climate. Most sea level rise (SLR) vulnerability assessments are undertaken using the easily implemented bathtub approach, where areas adjacent to the sea and below a given elevation are mapped using a deterministic line dividing potentially inundated from dry areas. This method only requires elevation data usually in the form of a digital elevation model (DEM). However, inherent errors in the DEM and spatial analysis of the bathtub model propagate into the inundation mapping. The aim of this study was to assess the impacts of spatially variable and spatially correlated elevation errors in high-spatial resolution DEMs for mapping coastal inundation. Elevation errors were best modelled using regression-kriging. This geostatistical model takes the spatial correlation in elevation errors into account, which has a significant impact on analyses that include spatial interactions, such as inundation modelling. The spatial variability of elevation errors was partially explained by land cover and terrain variables. Elevation errors were simulated using sequential Gaussian simulation, a Monte Carlo probabilistic approach. 1,000 error simulations were added to the original DEM and reclassified using a hydrologically correct bathtub method. The probability of inundation to a scenario combining a 1 in 100 year storm event over a 1 m SLR was calculated by counting the proportion of times from the 1,000 simulations that a location was inundated. This probabilistic approach can be used in a risk-aversive decision making process by planning for scenarios with different probabilities of occurrence. For example, results showed that when considering a 1% probability exceedance, the inundated area was approximately 11% larger than mapped using the deterministic bathtub approach. The probabilistic approach provides visually intuitive maps that convey uncertainties inherent to spatial data and analysis. PMID:25250763

Leon, Javier X.; Heuvelink, Gerard B. M.; Phinn, Stuart R.

2014-01-01

34

The HELI-DEM model estimation  

NASA Astrophysics Data System (ADS)

Global DEMs are fundamental for global applications and are necessary also at the local scale, in regions where local models are not available. Local DEMs are preferred when they are available and if are characterized by better accuracies and resolutions. In general, two problems arise. Firstly, an interest region could be patched by several partly overlapping DEMs that present similar accuracies and spatial resolutions: they should be merged in a unified model. Moreover, even when the interest region is covered by one unified DEM, local DEMs with better accuracy could be available and should be used to locally improve it. All these problems have been addressed within HELI-DEM project. HELI-DEM (HELvetia-Italy Digital Elevation Model) is a project that has been funded by the European Regional Development Fund (ERDF) within the Italy-Switzerland cooperation program. It started in 2010 and finished at the end of 2013. The involved institutions in the project were Fondazione Politecnico di Milano, Politecnico di Milano, Politecnico di Torino, Regione Lombardia, Regione Piemonte and Scuola Universitaria della Svizzera Italiana. One specific aim of the project was the creation and the publication of a unified Digital Elevation Model for the part of the Alps between Italy and Switzerland. The interest area is prevalently mountainous, with heights that range from about 200 m to 4600 m. Three low Resolution DTMs (20-25-50 m of resolution) are available that partly overlap and patch the whole project area: they are characterized by accuracies of some meters. Also High Resolution DTMs (1-5 m) are available: they have accuracies of some decimeters but cover limited areas of the project. The various models are available in different reference frames (the European ETRF89 and the Italian Roma40) and are gridded either in cartographic or geographic coordinates. Before merging them, a validation of the input data has been performed in three steps: cross validation of LR DTMs, validation of LR DTMs by HR DTMs and final check by geodetic techniques. The comparisons confirm the accuracy of HR data and the presence of few local anomalies in LR DTMs. Considering the goal of the project and the previous results, two different DTMs have been produced. Both of them cover the whole project area (boundaries: ? = 7.80° East and ? = 10.70° East, ? = 45.10° North e ? = 46.70° North). They are gridded in ETRF2000 geographical coordinates and their spatial resolution is 2 × 10-4 degrees. The former has been obtained by interpolating and merging all the input LR DTMs on a new common grid. This DTM has been called HD-1. HD-1 presents the same local anomalies of the LR DTMs used as input for the interpolation: therefore, at least in areas where better data (HR DTMs) are available, its correction was needed. In order to avoid sharp discontinuities, corrections obtained by HR DTMs have been filtered by a numerical FFT approach before applying them. The result of this correction has been called HD-2. HD-1 and HD-2 have already been published by an open access geoservice.

Biagi, L.; Caldera, S.; Carcano, L.; Lucchese, A.; Negretti, M.; Sansò, F.; Triglione, D.; Visconti, M. G.

2014-04-01

35

Reliability Analysis of the new Link between the Beam Interlock System and the LHC Beam Dumping System Zuverlässigkeitsanalyse der neuen Verbindung zwischen dem Beam Interlock System und dem LHC Beam Dumping System  

E-print Network

The nominal stored energy in each LHC beam is 360 MJ, surpassing the beam energy of other accelerators by orders of magnitude. This energy threatens to damage accelerator components in case of uncontrolled beam losses To avoid damage of accelerator equipment due to impacting beam, the controlled removal of the LHC beams from the collider rings towards the dump block must be guaranteed at all times. Therefore, the LHC Beam Dumping System was built according to high reliability standards. To further reduce the risk of incapability to dump the beams in case of correlated failures in the redundant system, a new direct link from the LHC Beam Interlock System to the Re-triggering Lines of the LHC Beam Dumping System will be implemented for the startup with beam in 2015. This link represents a diverse redundancy to the current implementation, which should neither significantly increase the risk for so-called Asynchronous Beam Dumps nor compromise machine availability. Therefore, a reliability analysis down to the co...

Vatansever, Volkan

36

Precise Global DEM Generation by ALOS PRISM  

NASA Astrophysics Data System (ADS)

The Japan Aerospace Exploration Agency (JAXA) generated the global digital elevation/surface model (DEM/DSM) and orthorectified image (ORI) using the archived data of the Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) onboard the Advanced Land Observing Satellite (ALOS, nicknamed "Daichi"), which was operated from 2006 to 2011. PRISM consisted of three panchromatic radiometers that acquired along-track stereo images. It had a spatial resolution of 2.5 m in the nadir-looking radiometer and achieved global coverage, making it a suitable potential candidate for precise global DSM and ORI generation. In the past 10 years or so, JAXA has conducted the calibration of the system corrected standard products of PRISM in order to improve absolute accuracies as well as to validate the high-level products such as DSM and ORI. In this paper, we introduce an overview of the global DEM/DSM dataset generation project, including a summary of ALOS and PRISM, in addition to the global data archive status. It is also necessary to consider data processing strategies, since the processing capabilities of the level 1 standard product and the high-level products must be developed in terms of both hardware and software to achieve the project aims. The automatic DSM/ORI processing software and its test processing results are also described.

Tadono, T.; Ishida, H.; Oda, F.; Naito, S.; Minakawa, K.; Iwamoto, H.

2014-04-01

37

Dem Lebendigen Geist Festschrift zur Wiedererffnung der Neuen Universitt  

E-print Network

Dem Lebendigen Geist Festschrift zur Wiedereröffnung der Neuen Universität 625 Jahre Ruperto Carola Bundeskanzler 1982­1998 Schirmherr der Spendenkampagne 18 Dem Lebendigen Geist Zentrale Spendenkampagne zum 625. Jubiläum 21 Neue Räume für den »Lebendigen Geist« 27 Die Neue Aula 31 Förderer: Heidemarie und Curt

Heermann, Dieter W.

38

Auf dem Weg DIE GOETHE-UNIVERSITT IST  

E-print Network

Studierenden gehört die Johann Wolfgang Goethe-Universität zu den zehn größten Hochschulen in Deutschland wurde die Goethe-Universität von Frankfurter Bürgern gegründet. Am 1. Januar 2008 gewann sie mit derAuf dem Weg zur Spitze #12;#12;DIE GOETHE-UNIVERSITÄT IST AUF DEM WEG AN DIE SPITZE Mit 42000

39

DIGITAL ELEVATION MODEL (DEM) FILES (30 M) FOR VIRGINIA  

EPA Science Inventory

Digital Elevation Model (DEM) files, 30-m resolution, for Virginia from US Geological Survey Web site: http://edcwww.cr.usgs.gov/doc/edchome/ndcdb/7_min_dem/states/VA.html Files listed for VA but centered in TN, WV, and NC are not included. All file archives were downloaded an...

40

Digital Elevation Model (DEM) Generation from SAR Interferometry  

NASA Astrophysics Data System (ADS)

SAR Interferometry (InSAR) provides data that contain information relating to the phase and coherence components of the backscattered radar signals. Phase information is used to derive Digital Elevation Models (DEM). This paper presents the results of an analysis of the accuracy of InSAR DEM derived from ESAR L-band airborne repeat-pass fully polarimetric InSAR data, which were acquired over Thetford Forest, in the east of England. An area with no tree cover of about 300m by 300m in size was chosen as a test site. Then InSAR DEMs for L-band HH, HV and VV polarisations were generated. The accuracy of the InSAR-derived DEMs was deduced by comparison with reference DEMs, which were generated from field data acquired from both Global Positioning System (GPS) &spot height survey and a Lidar DEM. The Lidar DEM was acquired by the UK Environment Agency. The poster reports the results of these comparisons and some concluding remarks about the relationship between the accuracy of the InSAR DEMs, polarization mode, and the nature of the ground surface cover are highlighted.

Kamaruddin, M.; Hamid, J. R. Abdul; Mather, P. M.; Balzter, H.

2003-04-01

41

Robust methods for assessing the accuracy of linear interpolated DEM  

NASA Astrophysics Data System (ADS)

Methods for assessing the accuracy of a digital elevation model (DEM) with emphasis on robust methods have been studied in this paper. Based on the squared DEM residual population generated by the bi-linear interpolation method, three average-error statistics including (a) mean, (b) median, and (c) M-estimator are thoroughly investigated for measuring the interpolated DEM accuracy. Correspondingly, their confidence intervals are also constructed for each average error statistic to further evaluate the DEM quality. The first method mainly utilizes the student distribution while the second and third are derived from the robust theories. These innovative robust methods possess the capability of counteracting the outlier effects or even the skew distributed residuals in DEM accuracy assessment. Experimental studies using Monte Carlo simulation have commendably investigated the asymptotic convergence behavior of confidence intervals constructed by these three methods with the increase of sample size. It is demonstrated that the robust methods can produce more reliable DEM accuracy assessment results compared with those by the classical t-distribution-based method. Consequently, these proposed robust methods are strongly recommended for assessing DEM accuracy, particularly for those cases where the DEM residual population is evidently non-normal or heavily contaminated with outliers.

Wang, Bin; Shi, Wenzhong; Liu, Eryong

2015-02-01

42

Oligophrenia phenylpyruvia unter dem Bild der Blitz, Nick und Salaamkrämpfe  

Microsoft Academic Search

Ausgehend von der Beobachtung eines 9monatigen Kindes mit Phenylpyruvischer Oligophrenie, bei dem aus dem EEG-Befund das spätere Auftreten von Blitz-, Nick- und Salaamkrämpfen vorausgesagt werden konnte, wird auf die relativ häufige Bevorzugung dieses Anfallsbildes als Frühmanifestation der Föllingschen Krankheit hingewiesen.

Hans Gött

1957-01-01

43

Die Jahrhundert-Messung Mithilfe des Venus-Transits wurde die Distanz zwischen Erde und Sonne ermittelt  

E-print Network

Die Jahrhundert-Messung Mithilfe des Venus-Transits wurde die Distanz zwischen Erde und Sonne Astronomen wussten zwar, dass zum Beispiel die Entfernung zwi- schen Erde und Jupiter fünfmal so gross ist wie die Distanz von der Erde zur Sonne. Sie hatten jedoch keine genaue Vorstellung davon, wie gross

Imamoglu, Atac

44

Effects of DEM Resolutions for Site Classification in Southeastern Korea  

NASA Astrophysics Data System (ADS)

Site characteristic is an important input parameter in the hazard assessments of earthquakes, liquefactions, landslides and other natural disasters. We prepared a preliminary site classification map using the geologic and topographic maps of Korea in the previous study, in which slope and elevation data derived from digital elevation model (DEM) were used as important indicators to infer the shear wave velocity in the upper 30 m (Vs30). We may use DEMs in different resolution, which may influence the results of the site classification. In order to explore the effects of different DEM resolutions, three DEMs in 3, 9, and 30 arc-seconds are used to develop and to compare independent site classification maps of southeastern Korea. We observed the largest difference (approximately 5%) in site C classified by the slope criteria using 9 and 30 arc-sec DEMs. We also found variations as large as 3% in site B and E. In the area where large variation of slope occurs, for example mountainous region with occasional flat topography, high resolution DEM can detect variations over short distance. However, site classification map developed using a low resolution DEM is characterized by smoother variations in topography, thus results in averaged site classes. We also note only minor differences (less than 0.7%) in the elevation-based site classification maps using three different DEMs. Apparently, it is suitable to use a higher resolution DEM to represent the rugged topography in southeastern Korea. Finally, the site classification using higher resolution DEM will provide useful information in the study of regional hazard estimation and risk management.

Kang, S.; Kim, K.; Suk, B.

2010-12-01

45

The 0.4 Arc-Sec Tandem-X Intermediate dem with Respect to the Srtm and Aster Global Dems  

NASA Astrophysics Data System (ADS)

Recently a preliminary version of the new global DEM collected by the TanDEM-X mission became available to the scientific community: the TanDEM-X Intermediate DEM (IDEM) version. It is available over selected areas of the globe with a pixel spacing of 0.4, 1 and 3 arc-seconds. This paper presents the TanDEM-X IDEM with respect to global and local elevation data over Aegean Islands with mountainous terrain: the SRTM and ASTER global DEMs, and the national network of triangulation pillars (trig-points) and national archive Digital Terrain Model. Possible systematic 3D translations between global DEMs and local data are also determined and the relative gain in accuracy is assessed. TanDEM-X IDEM is shown to be dramatically enhanced with respect to the other global DEMs although a few jitters exist.

Vassilaki, D. I.; Stamos, A. A.

2015-03-01

46

Evaluation of Time Series TanDEM-X Digital Elevation Models  

NASA Astrophysics Data System (ADS)

Digital Elevation Model (DEM) is an important input for geo-spatial analysis. For various applications like flood management, ortho rectification of remote sensing images, navigation, architectural works, defence, etc., high resolution DEM is required. TanDEM-X mission was launched in 2010 to obtain high resolution global DEM with HTRI-3 standard. SAR interferometry (InSAR) technique is used for DEM generation from TanDEM-X SAR data. The accuracy of DEM depends on many parameters like height ambiguity, incidence angle, polarization, etc. In this study, time series TanDEM-X data spanning over 3 years, had processed for generating DEM at the spatial resolution of 6 m and their accuracy had studied using DGPS elevation data and SRTM 90 m DEM. The products generated during DEM generation process are DEM, precision (or height error), coherence, layover and shadow images. Using weighted average fusion technique, ascending and descending DEMs are fused for improving the quality of DEM and to reduce invalid pixels corresponding to layover and shadow areas. Results from time series data were analysed and found RMSE error of fused DEMs is in the range of 2 m to 4 m, while individual DEM has accuracy of 3 m to 6 m with respect to DGPS elevation data. Fused DEMs are having high accuracy as well as less voids. The reduction of voids by fusion, ranges from 40 to 85 % in different combinations of data.

Jain, M.; Deo, R.; Kumar, V.; Rao, Y. S.

2014-11-01

47

Zwischen schöpferischer Gewalt und aggressivem Pathos. Lehren im Film »Der Club der toten Dichter«  

Microsoft Academic Search

\\u000a Der Film Dead Poets’ Society wurde 1989 in den USA veröffentlicht und kam im Januar 1990 auch in Deutschland in die Kinos. Regisseur Peter Weir und Drehbuchautor\\u000a Tom Schulman erzählen darin die Geschichte eines Lehrers, der mit seinen liberalen Lehrmethoden an einem autoritär geführten\\u000a konservativen Eliteinternat für Jungen insofern scheitert, als er nach dem Suizid eines Schülers, für den er

Michael Wimmer

48

DEM generation from contour lines based on Voronoi diagram  

NASA Astrophysics Data System (ADS)

In this paper, a method to generate a digital elevation model (DEM) from contour lines is proposed. The generation of DEM can be described as an iterative procedure, in which new contours are obtained by a weighted Euclidian distance transformation and a consequent extraction of boundaries of the Voronoi diagram. It is characterized by the linear interpolation with each iteration for generating contours with half contour interval of earlier ones. The performance of the method is analyzed by both numerical tests and a topographic map test. Five mathematical surfaces are employed in numerical tests. DEMs generated by the method proposed are comparatively evaluated with other methods, including TLI (triangulated irregular network with linear interpolation) and TOPOGRID in ArcGIS. This algorithm gives an effective method for producing DEM with acceptable accuracy and simple operations.

Fan, Qingsong; Hu, Peng

2007-06-01

49

Mitteilungen aus dem Brenner-Archiv Nr. 30/2011  

E-print Network

Vater" 69 Cornelius Hell: ,,Maria auf dem Heiligen Strich". Edwin Wolfram Dahl und die religiöse Komponente in seinem Werk 79 Essays Michael Sallinger: Anbiederungen. Beinahe. Beim Auslaufen der Signaturen

Breu, Ruth

50

Mssbauerspektrometer auf dem Mars Mssbauer spectrometer on Mars  

E-print Network

MMOS Mössbauerspektrometer auf dem Mars Mössbauer spectrometer on Mars #12;Einleitung Mars ist dünne Atmosphäre, die Temperaturen auf der Marsoberfläche erreichen bis zu 20°C und ein Tag auf dem Mars (,,Sol") dauert nur 39 Minuten länger als ein Tag auf der Erde. Der Mars ist daher ein begehrtes

Hanke-Bourgeois, Martin

51

Discrete Element Modeling (DEM) of Triboelectrically Charged Particles: Revised Experiments  

NASA Technical Reports Server (NTRS)

In a previous work, the addition of basic screened Coulombic electrostatic forces to an existing commercial discrete element modeling (DEM) software was reported. Triboelectric experiments were performed to charge glass spheres rolling on inclined planes of various materials. Charge generation constants and the Q/m ratios for the test materials were calculated from the experimental data and compared to the simulation output of the DEM software. In this paper, we will discuss new values of the charge generation constants calculated from improved experimental procedures and data. Also, planned work to include dielectrophoretic, Van der Waals forces, and advanced mechanical forces into the software will be discussed.

Hogue, Michael D.; Calle, Carlos I.; Curry, D. R.; Weitzman, P. S.

2008-01-01

52

Removing non-ground points from automated photo-based DEM and evaluation of its accuracy with LiDAR DEM  

NASA Astrophysics Data System (ADS)

Three sets of DEM, including LiDAR, stereo photo based DEM, and contour-based DEM, were created using different tools and sources. Because different tools produce different raster data sets, they were reprojected into the same coordinate system and converted to point clouds as vector format, then a triangulated irregular network (TIN) retaining all grid or mass points was created from each point coverage. Corresponding orthophoto involved in extracting stereo photo DEM, classified by object-oriented approach to create vector polygons representing non-ground points (building and vegetation classes) and bare-ground elevation points. Non-ground points were removed from stereo pairs DEM using classified orthophoto polygons, and filled with contour DEM data. Also a 5th order trend surface over photo-based DEM was fitted and non-ground points were removed and filled using local interpolation. It was observed that automated photo-based extraction yields high precision terrain models in a short time, reducing manual editing; their accuracy is strictly related to image quality and terrain features. Results showed that such photogrammetric extracted DEM represents better accuracy along x and y directions than LiDAR does, while LiDAR has the best vertical accuracy, compared to other DEMs. The differences between horizontal errors are large since there were no significant differences between vertical errors of LiDAR and photo-based DEM. This indicates that there is a good correlation between elevation points of DEMs, and a stereo pair-based DEM can be a good substitute, whenever LiDAR is not affordable. This study provides several important insights into the magnitudes and spatial patterns of LiDAR and photo-based DEM errors, further studies need to verify the error extent in more diverse landscape. However, automated photo-based DEM extraction is currently an efficient method for collecting data useful for rural and small study area.

Dehvari, Abdolhamid; Heck, Richard John

2012-06-01

53

Melker Meilensteine auf dem Weg in ein naturwissenschaftliches Zeitalter - Glanzlichter der Ausstellung zum Internationalen Astronomiejahr 2009 in der Melker Stiftsbibliothek.  

NASA Astrophysics Data System (ADS)

Das Mittelalter wird weithin als die dunkle Epoche in der Geschichte der Europäischen Wissenschaften betrachtet, und insbesondere das Leben in den Klöstern galt lange Zeit als frei von jeglichem Interesse für Naturwissenschaften abseits der Medizin. Im Mittelalter galt die Astronomie bloß als Mittel zum Zweck, um religiöse und zivile Kalender erstellen zu können. Durch den Bestand der Handschriftenkammer der Melker Stiftsbibliothek eröffnet sich uns eine neue Sichtweise auf das gegen Ende des Mittelalters wachsende Interesse an den Naturwissenschaften. Dies wurde durch die starke Aufwertung der Klosterbibliothek im Rahmen der 'Melker Reform' im 15. Jahrhundert noch weiter verstärkt. Diese Epoche fällt mit der Frühphase der Universität Wien und der 'ersten Wiener Schule der Astronomie' zusammen. Dieser Artikel beleuchtet ausgewählte astronomischen Werke in der Melker Stiftsbibliothek zwischen dem frühen 9 und dem 18. Jahrhundert. Einen Schwerpunkt stellt das Wirken der Wiener Schule der Astronomie dar, wobei wir u.a. die Melker Abschrift von Peuerbachs Gutachten über den Kometen von 1456 sowie die im Stift Melk durchgeführte Beobachtung der Mondfinsternis von 1457 durch Regiomontanus und Peuerbach beleuchten. Dieser Beitrag ist der einführende Übersichtsartikel zum Ausstellungsprojekt in der Melker Stiftsbibliothek im Rahmen des Internationalen Jahres der Astronomie 2009. The medieval period is commonly seen as a dark epoch for science in Europe. Especially monasteries were seen as institutions without interest in natural sciences except for medicine. Astronomy was allegedly only a tool to construct religious and civil calendars. The inventory of the medieval manuscript collection of the library of the Abbey of Melk allows a new view on the growing interest in the exact sciences towards the end of the medieval ages. This interest was intensified through the increased importance of the monastery library due to the monastery reform concept, created in Melk Abbey in the 15th century. This epoch coincides with the early phase of the University of Vienna and the first Viennese School of Astronomy. This paper discusses selected pieces of astronomical works between the early 9th and the 18th century. The focus is set on the interaction with the members of the Viennese School of Astronomy, e.g., the transcript of Peuerbach's expertise on the comet of 1456 which was presumably produced by a monk of Melk, and the observations of the lunar eclipse 1457 by Peuerbach and Regiomontanus in Melk Abbey. This paper is the introductory overview article on the exhibition in the monastery library of Melk Abbey for the International Year of Astronomy, IYA2009.

Beck, Paul G.; Zotti, Georg

2009-06-01

54

Precise baseline determination for the TanDEM-X mission  

NASA Astrophysics Data System (ADS)

The TanDEM-X mission will strive for generating a global precise Digital Elevation Model (DEM) by way of bi-static SAR in a close formation of the TerraSAR-X satellite, already launched on June 15, 2007, and the TanDEM-X satellite to be launched in May 2010. Both satellites carry the Tracking, Occultation and Ranging (TOR) payload supplied by the GFZ German Research Centre for Geosciences. The TOR consists of a high-precision dual-frequency GPS receiver, called Integrated GPS Occultation Receiver (IGOR), and a Laser retro-reflector (LRR) for precise orbit determination (POD) and atmospheric sounding. The IGOR is of vital importance for the TanDEM-X mission objectives as the millimeter level determination of the baseline or distance between the two spacecrafts is needed to derive meter level accurate DEMs. Within the TanDEM-X ground segment GFZ is responsible for the operational provision of precise baselines. For this GFZ uses two software chains, first its Earth Parameter and Orbit System (EPOS) software and second the BERNESE software, for backup purposes and quality control. In a concerted effort also the German Aerospace Center (DLR) generates precise baselines independently with a dedicated Kalman filter approach realized in its FRNS software. By the example of GRACE the generation of baselines with millimeter accuracy from on-board GPS data can be validated directly by way of comparing them to the intersatellite K-band range measurements. The K-band ranges are accurate down to the micrometer-level and therefore may be considered as truth. Both TanDEM-X baseline providers are able to generate GRACE baselines with sub-millimeter accuracy. By merging the independent baselines by GFZ and DLR, the accuracy can even be increased. The K-band validation however covers solely the along-track component as the K-band data measure just the distance between the two GRACE satellites. In addition they inhibit an un-known bias which must be modelled in the comparison, so the differences between the computed baselines and the K-band ranges vary around a mean. In the end a systematic deviation or bias cannot be detected this way. A 3-D assessment of the baseline accuracies including biases can be gained by comparison of independently derived baselines as here from GFZ and DLR. Indeed it turns out that the different baselines show systematic differences of a few millimeters. From this it can be concluded that for the TanDEM-X mission an unknown bias in the baselines is possible which in turn would hurt the anticipated DEM accuracy limit. In order to control a possible baseline bias, a calibration chain via SAR calibration data takes has been invented in the TanDEM-X ground segment. This chain delivers corrections to the baseline bias so that unbiased baselines with sub-millimeter accuracies can be provided to secure the DEM accuracy requirement.

Koenig, Rolf; Moon, Yongjin; Neumayer, Hans; Wermuth, Martin; Montenbruck, Oliver; Jäggi, Adrian

55

Title: Greater Toronto Area Digital Elevation Model (DEM) Data Creator /  

E-print Network

Title: Greater Toronto Area Digital Elevation Model (DEM) Data Creator / Copyright Owner: Ontario: 10 cm resolution Coordinates: N/A Index Map: N/A Keywords (Place): Greater Toronto Area, Ontario; Toronto, Ontario Keywords (Subject): Digital Terrain Models; Elevations Restrictions: Data is licensed

56

TSUNAMI INUNDATION MAPPING FOR OCEAN CITY, MD NGDC DEM  

E-print Network

TSUNAMI INUNDATION MAPPING FOR OCEAN CITY, MD NGDC DEM BY BABAK TEHRANIRAD, SAEIDEH BANIHASHEMI BY THE NATIONAL TSUNAMI HAZARD MITIGATION PROGRAM NATIONAL WEATHER SERVICE GRANT NA10NWS4670010 CENTER FOR APPLIED COASTAL RESEARCH Ocean Engineering Laboratory University of Delaware Newark, Delaware 19716 #12;Tsunami

Kirby, James T.

57

Influence of DEM interpolation methods in Drainage Analysis  

Microsoft Academic Search

The accuracy of the Digital Elevation Models (DEMs) interpolated using four different methods was compared in two small watersheds in the Ecuadorian Andes. The interpolation methods compared were Inverse Distance Weighted, radial basis functions, ordinary Kriging, and TOPOGRID. A qualitative comparison was made between the stream network modeled in Arc Hydro and the digitized stream network. Modeled contour lines were

Manuel Peralvo

58

DIGITAL ELEVATION MODEL (DEM) FILES (30 M) FOR NORTH CAROLINA  

EPA Science Inventory

Digital Elevation Model files, 30-m resolution, for North Carolina from US Geological Survey Web site: http://edcwww.cr.usgs.gov/doc/edchome/ndcdb/7_min_dem/states/NC.html Files listed for NC but centered in TN, GA, and VA are not included. All file archives were downloaded an...

59

EXOTICPEST ALERT Horse chestnut leaf miner, Cameraria ohridella Desch. & Dem.  

E-print Network

EXOTICPEST ALERT Horse chestnut leaf miner, Cameraria ohridella Desch. & Dem. (Lepidoptera in the premature defoliation of many horse chestnut trees. Horse chestnuts are widely used in prominent amenity, becoming less frequent northwards. Occasionally a horse chestnut tree is seen with its leaflets browned

60

Spielerisches Erlernen der Programmierung mit dem Java-Hamster-Modell  

E-print Network

Spielerisches Erlernen der Programmierung mit dem Java- Hamster-Modell Dietrich Boles Department Oldenburg boles@informatik.uni-oldenburg.de Abstract: Das Java-Hamster-Modell ist ein spezielles Programmierkonzepte und den Programmentwurf kennen, indem sie so genannte Hamster-Programme entwickeln, mit denen sie

Appelrath, Hans-Jürgen

61

Spatial Characterization of Landscapes through Multifractal Analysis of DEM  

PubMed Central

Landscape evolution is driven by abiotic, biotic, and anthropic factors. The interactions among these factors and their influence at different scales create a complex dynamic. Landscapes have been shown to exhibit numerous scaling laws, from Horton's laws to more sophisticated scaling of heights in topography and river network topology. This scaling and multiscaling analysis has the potential to characterise the landscape in terms of the statistical signature of the measure selected. The study zone is a matrix obtained from a digital elevation model (DEM) (map 10 × 10?m, and height 1?m) that corresponds to homogeneous region with respect to soil characteristics and climatology known as “Monte El Pardo” although the water level of a reservoir and the topography play a main role on its organization and evolution. We have investigated whether the multifractal analysis of a DEM shows common features that can be used to reveal the underlying patterns and information associated with the landscape of the DEM mapping and studied the influence of the water level of the reservoir on the applied analysis. The results show that the use of the multifractal approach with mean absolute gradient data is a useful tool for analysing the topography represented by the DEM. PMID:25177728

Aguado, P. L.; Del Monte, J. P.; Moratiel, R.; Tarquis, A. M.

2014-01-01

62

3D DEM SIMULATIONS OF A HIGH SHEAR MIXER  

Microsoft Academic Search

Mixing of granular materials at high shear rates is poorly understood. The particle trajectories are non-trivial due to recirculation regions resulting from the use of mixing impellers. These regions can greatly influence the segregation and mixing of materials. Three-dimensional simulations using the Discrete Element Method (DEM) have been performed to investigate high shear mixing in a granular bed. A vertical

Matthew SINNOTT; Paul CLEARY

63

Discrete element modeling (DEM) of triboelectrically charged particles: Revised experiments  

Microsoft Academic Search

In a previous work, the addition of basic screened Coulombic electrostatic forces to an existing commercial discrete element modeling (DEM) software was reported. Triboelectric experiments were performed to charge glass spheres rolling on inclined planes of various materials. Charge generation constants and the Q\\/m ratios for the test materials were calculated from the experimental data and compared to the simulation

M. D. Hogue; C. I. Calle; D. R. Curry; P. S. Weitzman

2009-01-01

64

A beginner's guide to stereo-derived DEM production and analysis using ISIS, ASP, and ArcMap  

E-print Network

A beginner's guide to stereo-derived DEM production and analysis using ISIS, ASP, and ArcMap v. 1GIS/ArcMap..............................................7 3. Creating DEMs using ASPGIS.......................................................................................12 3.4.3. Visualising the DEM in ASP

Rathbun, Julie A.

65

The TanDEM-X Digital Elevation Model and Terrestrial Impact Craters  

NASA Astrophysics Data System (ADS)

The Digital Elevation Model (DEM) derived in the TanDEM-X mission is generated from data of the German X-band TerraSAR-X and TanDEM-X satellites, launched in June 2007 and June 2010, respectively. The complete final TanDEM-X DEM will be available by 2015. It achieves global coverage together with an accuracy in the sub-10 m range and a spatial resolution of 12 m at the equator. Thus it exceeds the quality of current elevation models generated from space-borne remote sensing data, e.g., SRTM X-band (15m/30m with limited coverage) considerably. The TanDEM-X DEM supports studies of terrestrial impact craters by revealing the morphology and topography of simple and complex structures, together with the surrounding terrain, in great detail - even for craters in very remote areas. In a first approach we apply the TanDEM-X digital elevation data to the impact crater record of the exposed entries in the Earth Impact Database (EID) of the Planetary and Space Science Center at the University of New Brunswick, Canada. This allows evaluation of how structures of confirmed origin are reflected in the TanDEM-X DEM data. Our early assessment analyses - using intermediate DEM processing products - suggest that of the about 120 EID entries of the exposed type 80%-90% can be identified in the DEM data. As the final elevation data successively will emerge during processing, we will generate for all known impact structures with visible surface features a homogeneous set of information extracted from the TanDEM-X DEM including, e.g., high precision maps, elevation profiles, etc. This catalogue can be used for further detailed studies or the development of search algorithms for potential impact features in selected areas. This presentation describes the current status of our research and illustrates several TanDEM-X DEM maps of known terrestrial impact craters.

Gottwald, Manfred; Harris, Alan; Fritz, Thomas; Breit, Helko; Schaettler, Birgit

66

Das Zusammenleben des Menschen mit dem Braunbären (Ursus arctos) in den Westkarpaten  

Microsoft Academic Search

Im Jahr 1932, als mit dem ganzjährigen Schutz der Bären in den Westkarpaten begonnen wurde, lebten von ihnen auf dem Gebiet der Slowakei nur noch etwa 20. Nach dem zweiten Weltkrieg waren es 50 bis 80, im Jahre 1967 um die 300 und in der Gegenwart schon um die 600 auf einer Fläche von ungefähr 1,13 Mill. ha Wald. Ab

P. Hell; F. Bevilaqua

1988-01-01

67

Assessment of Dem Quality for Characterizing Surface Roughness Using Close Range Digital Photogrammetry  

Microsoft Academic Search

This paper presents a procedure for assessing the quality of a digitalelevation model (DEM) which has been applied to the output of a normalizedcross correlation based stereomatching algorithm. Using semimetricphotography of natural gravel river bed surfaces acquired in the field,digital photogrammetry was used to extract DEMs automatically for use incharacterizing surface roughness properties.The procedure for assessing DEM quality involves examination

J. B. Butler; J. H. Chandler

1998-01-01

68

Constructing DEM from characteristic terrain information using HASM method  

NASA Astrophysics Data System (ADS)

In the construction of DEM, terrain features (e.g. valleys or stream lines, ridges, peaks, saddle points) are important for improving DEM accuracy and saw many applications in hydrology, precision agriculture, military trajectory planning, etc. HASM (High Accuracy Surface Modeling) is a method for surface modeling, which is based on the theory of surface. Presently, HASM is only used for scattered point's interpolation. So the work in this paper attempts to construct DEM based on the characteristic terrain information as stream lines and scattered points by HASM method. The course is described as the following steps. Firstly TIN (Triangulated Irregular Network) from the scattered points is generated. Secondly, each segment of the stream lines is well oriented to represent stream lines' flow direction, and a tree data structure (that has parent, children and brothers) is used to represent the whole stream lines' segments. A segment is a curve which does not intersect with other segments. A Water Course Flow (WCF) line is a set of segment lines connected piecewise but without overlapping or repetition, from the most upper reaches to the most lower reaches. From the stream lines' tree data structure, all the possible WCF lines are enumerated, and the start point and end point of each WCF lines is predicted from searching among the TIN. Thirdly, given a cell size, a 2-D matrix for the research region is built, and the values of the cells who were traversed by the stream lines by linear interpolation among each WCF lines. Fourthly, all the valued cells that were passed through by the stream line and that were from the scattered points are gathered as known scattered sampling points, and then HASM is used to construct the final DEM. A case study on the typical landform of plateau of China, KongTong gully of Dongzhi Plateau, Qingyang, Gausu province, is presented. The original data is manually vecterized from scanned maps 1:10,000, includes scattered points, stream lines, contour lines, precipitous cliff lines of a region of area about 4×5 square km. For simplicity only the former two kinds of data sources are used. By Comparing with the result from stream-line-constrained TIN and hydrologically correct DEM construction method Thin plate Spline (TPS, that is implemented as command TopoToRaster in ArcGIS 9.0 and later version)through visual inspection, HASM gets a more desirable DEM and more reasonable integration of information of the terrain features. Finally, some challenges and future research about HASM is also given.

Song, Dunjiang; Yue, Tianxiang; Du, Zhengping; Wang, Qingguo

2010-11-01

69

Constructing DEM from characteristic terrain information using HASM method  

NASA Astrophysics Data System (ADS)

In the construction of DEM, terrain features (e.g. valleys or stream lines, ridges, peaks, saddle points) are important for improving DEM accuracy and saw many applications in hydrology, precision agriculture, military trajectory planning, etc. HASM (High Accuracy Surface Modeling) is a method for surface modeling, which is based on the theory of surface. Presently, HASM is only used for scattered point's interpolation. So the work in this paper attempts to construct DEM based on the characteristic terrain information as stream lines and scattered points by HASM method. The course is described as the following steps. Firstly TIN (Triangulated Irregular Network) from the scattered points is generated. Secondly, each segment of the stream lines is well oriented to represent stream lines' flow direction, and a tree data structure (that has parent, children and brothers) is used to represent the whole stream lines' segments. A segment is a curve which does not intersect with other segments. A Water Course Flow (WCF) line is a set of segment lines connected piecewise but without overlapping or repetition, from the most upper reaches to the most lower reaches. From the stream lines' tree data structure, all the possible WCF lines are enumerated, and the start point and end point of each WCF lines is predicted from searching among the TIN. Thirdly, given a cell size, a 2-D matrix for the research region is built, and the values of the cells who were traversed by the stream lines by linear interpolation among each WCF lines. Fourthly, all the valued cells that were passed through by the stream line and that were from the scattered points are gathered as known scattered sampling points, and then HASM is used to construct the final DEM. A case study on the typical landform of plateau of China, KongTong gully of Dongzhi Plateau, Qingyang, Gausu province, is presented. The original data is manually vecterized from scanned maps 1:10,000, includes scattered points, stream lines, contour lines, precipitous cliff lines of a region of area about 4×5 square km. For simplicity only the former two kinds of data sources are used. By Comparing with the result from stream-line-constrained TIN and hydrologically correct DEM construction method Thin plate Spline (TPS, that is implemented as command TopoToRaster in ArcGIS 9.0 and later version)through visual inspection, HASM gets a more desirable DEM and more reasonable integration of information of the terrain features. Finally, some challenges and future research about HASM is also given.

Song, Dunjiang; Yue, Tianxiang; Du, Zhengping; Wang, Qingguo

2009-09-01

70

A comparative appraisal of hydrological behavior of SRTM DEM at catchment level  

NASA Astrophysics Data System (ADS)

The Shuttle Radar Topography Mission (SRTM) data has emerged as a global elevation data in the past one decade because of its free availability, homogeneity and consistent accuracy compared to other global elevation dataset. The present study explores the consistency in hydrological behavior of the SRTM digital elevation model (DEM) with reference to easily available regional 20 m contour interpolated DEM (TOPO DEM). Analysis ranging from simple vertical accuracy assessment to hydrological simulation of the studied Maithon catchment, using empirical USLE model and semidistributed, physical SWAT model, were carried out. Moreover, terrain analysis involving hydrological indices was performed for comparative assessment of the SRTM DEM with respect to TOPO DEM. Results reveal that the vertical accuracy of SRTM DEM (±27.58 m) in the region is less than the specified standard (±16 m). Statistical analysis of hydrological indices such as topographic wetness index (TWI), stream power index (SPI), slope length factor (SLF) and geometry number (GN) shows a significant differences in hydrological properties of the two studied DEMs. Estimation of soil erosion potentials of the catchment and conservation priorities of microwatersheds of the catchment using SRTM DEM and TOPO DEM produce considerably different results. Prediction of soil erosion potential using SRTM DEM is far higher than that obtained using TOPO DEM. Similarly, conservation priorities determined using the two DEMs are found to be agreed for only 34% of microwatersheds of the catchment. ArcSWAT simulation reveals that runoff predictions are less sensitive to selection of the two DEMs as compared to sediment yield prediction. The results obtained in the present study are vital to hydrological analysis as it helps understanding the hydrological behavior of the DEM without being influenced by the model structural as well as parameter uncertainty. It also reemphasized that SRTM DEM can be a valuable dataset for hydrological analysis provided any error/uncertainty therein is being properly evaluated and characterized.

Sharma, Arabinda; Tiwari, K. N.

2014-11-01

71

Development of parallel DEM for the open source code MFIX  

SciTech Connect

The paper presents the development of a parallel Discrete Element Method (DEM) solver for the open source code, Multiphase Flow with Interphase eXchange (MFIX) based on the domain decomposition method. The performance of the code was evaluated by simulating a bubbling fluidized bed with 2.5 million particles. The DEM solver shows strong scalability up to 256 processors with an efficiency of 81%. Further, to analyze weak scaling, the static height of the fluidized bed was increased to hold 5 and 10 million particles. The results show that global communication cost increases with problem size while the computational cost remains constant. Further, the effects of static bed height on the bubble hydrodynamics and mixing characteristics are analyzed.

Gopalakrishnan, Pradeep; Tafti, Danesh

2013-02-01

72

The Global Tandem-X Dem: Production Status and First Validation Results  

NASA Astrophysics Data System (ADS)

The TanDEM-X mission will derive a global digital elevation model (DEM) with satellite SAR interferometry. Two radar satellites (TerraSAR-X and TanDEM-X) will map the Earth in a resolution and accuracy with an absolute height error of 10m and a relative height error of 2m for 90% of the data. In order to fulfill the height requirements in general two global coverages are acquired and processed. Besides the final TanDEM-X DEM, an intermediate DEM with reduced accuracy is produced after the first coverage is completed. The last step in the whole workflow for generating the TanDEM-X DEM is the calibration of remaining systematic height errors and the merge of single acquisitions to 1°x1° DEM tiles. In this paper the current status of generating the intermediate DEM and first validation results based on GPS tracks, laser scanning DEMs, SRTM data and ICESat points are shown for different test sites.

Huber, M.; Gruber, A.; Wendleder, A.; Wessel, B.; Roth, A.; Schmitt, A.

2012-07-01

73

A new morphology algorithm for shoreline extraction from DEM data  

NASA Astrophysics Data System (ADS)

Digital elevation models (DEMs) are a digital representation of elevations at regularly spaced points. They provide an accurate tool to extract the shoreline profiles. One of the emerging sources of creating them is light detection and ranging (LiDAR) that can capture a highly dense cloud points with high resolution that can reach 15 cm and 100 cm in the vertical and horizontal directions respectively in short periods of time. In this paper we present a multi-step morphological algorithm to extract shorelines locations from the DEM data and a predefined tidal datum. Unlike similar approaches, it utilizes Lowess nonparametric regression to estimate the missing values within the DEM file. Also, it will detect and eliminate the outliers and errors that result from waves, ships, etc by means of anomality test with neighborhood constrains. Because, there might be some significant broken regions such as branches and islands, it utilizes a constrained morphological open and close to reduce these artifacts that can affect the extracted shorelines. In addition, it eliminates docks, bridges and fishing piers along the extracted shorelines by means of Hough transform. Based on a specific tidal datum, the algorithm will segment the DEM data into water and land objects. Without sacrificing the accuracy and the spatial details of the extracted boundaries, the algorithm should smooth and extract the shoreline profiles by tracing the boundary pixels between the land and the water segments. For given tidal values, we qualitatively assess the visual quality of the extracted shorelines by superimposing them on the available aerial photographs.

Yousef, Amr H.; Iftekharuddin, Khan; Karim, Mohammad

2013-03-01

74

stilen gelten, die dieser Tage gemeinhin unter dem Begriff  

E-print Network

erhoben wurde, berechtigt ge- wesen wäre, hätte jede chinesi- sche Frau, die vor 1906 in San Francisco. In San Francisco brach durch das Beben ein Feuer aus, in dem 3000 Menschen starben. Foto: The Bancroft I S I E R U N G Abbildung 1 Am 18.04.1906 wurde Kalifor- nien von einem Erdbeben er- schüttert

Vollmer, Heribert

75

Accuracy estimation of SRTM and Map-based DEMs using ICESat elevation data in Tibetan Plateau  

NASA Astrophysics Data System (ADS)

The Geoscience Laser Altimeter System (GLAS) instrument onboard the Ice, Cloud, and land Elevation Satellite (ICESat) provides elevation data with very high accuracy and can be used as ground truth to evaluate the vertical accuracy of an existing Digital Elevation Model (DEM). In this paper, we examine the differences between ICESat elevation data (from the 1064 nm channel) and Shuttle Radar Topography Mission (SRTM) 3-arc second resolution (90 m) and Map-based DEMs in the Qinghai-Tibet Plateau, China. Both DEMs are linearly correlated with ICESat elevation for different land covers, while the SRTM DEM shows a stronger correlation than that of Map-based DEM on each land cover type. The statistics indicated that land cover, surface slope and roughness do influence the vertical accuracy of the two DEMs. The standard deviation of the elevation differences between the two DEMs and ICESat elevation gradually increases as vegetation stands, terrain slope or surface roughness increases. The SRTM DEM consistently shows lower vertical error than that of the Map-based DEM. The overall means and standard deviations of the elevation differences between ICESat and SRTM and between ICESat and Map-based DEMs over the study area are 0.63 ?0?6?0"6¥7673?0?6?0"6¥7698 9.67 m and 4.44 ?0?6?0"6¥7673?0?6?0"6¥7698 21.19 m, respectively. Our results suggest that the SRTM DEM has higher accuracy than the Map-based DEM that we collected for the region. It is found that ICESat elevation increases as snow falling and decreases as snow or glacier melting, while the SRTM DEM gives a relative stable elevation of snow/land interface or a glacier elevation where the C-band can penetrate through or reach at. Therefore, this makes the S-DEM a promise dataset (baseline) in monitoring the glacier volume change since 2000.

Huang, X.; Xie, H.; Liang, T.; Yi, D.

2008-12-01

76

3D DEM analyses of the 1963 Vajont rock slide  

NASA Astrophysics Data System (ADS)

The 1963 Vajont rock slide has been modelled using the distinct element method (DEM). The open-source DEM code, YADE (Kozicki & Donzé, 2008), was used together with the contact detection algorithm proposed by Boon et al. (2012). The critical sliding friction angle at the slide surface was sought using a strength reduction approach. A shear-softening contact model was used to model the shear resistance of the clayey layer at the slide surface. The results suggest that the critical sliding friction angle can be conservative if stability analyses are calculated based on the peak friction angles. The water table was assumed to be horizontal and the pore pressure at the clay layer was assumed to be hydrostatic. The influence of reservoir filling was marginal, increasing the sliding friction angle by only 1.6?. The results of the DEM calculations were found to be sensitive to the orientations of the bedding planes and cross-joints. Finally, the failure mechanism was investigated and arching was found to be present at the bend of the chair-shaped slope. References Boon C.W., Houlsby G.T., Utili S. (2012). A new algorithm for contact detection between convex polygonal and polyhedral particles in the discrete element method. Computers and Geotechnics, vol 44, 73-82, doi.org/10.1016/j.compgeo.2012.03.012. Kozicki, J., & Donzé, F. V. (2008). A new open-source software developed for numerical simulations using discrete modeling methods. Computer Methods in Applied Mechanics and Engineering, 197(49-50), 4429-4443.

Weng Boon, Chia; Houlsby, Guy; Utili, Stefano

2013-04-01

77

A LBM-DEM solver for fast discrete particle simulation of particle-fluid flows  

NASA Astrophysics Data System (ADS)

The lattice Boltzmann method (LBM) for simulating fluid phases was coupled with the discrete element method (DEM) for studying solid phases to formulate a novel solver for fast discrete particle simulation (DPS) of particle-fluid flows. The fluid hydrodynamics was obtained by solving LBM equations instead of solving the Navier-Stokes equation by the finite volume method (FVM). Interparticle and particle-wall collisions were determined by DEM. The new DPS solver was validated by simulating a three-dimensional gas-solid bubbling fluidized bed. The new solver was found to yield results faster than its FVM-DEM counterpart, with the increase in the domain-averaged gas volume fraction. Additionally, the scalability of the LBM-DEM DPS solver was superior to that of the FVM-DEM DPS solver in parallel computing. Thus, the LBM-DEM DPS solver is highly suitable for use in simulating dilute and large-scale particle-fluid flows.

Xiong, Qingang; Madadi-Kandjani, Ehsan; Lorenzini, Giulio

2014-04-01

78

In need of combined topography and bathymetry DEM  

NASA Astrophysics Data System (ADS)

In many geoscience applications, digital elevation models (DEMs) are now more commonly used at different scales and greater resolution due to the great advancement in computer technology. Increasing the accuracy/resolution of the model and the coverage of the terrain (global model) has been the goal of users as mapping technology has improved and computers get faster and cheaper. The ETOPO5 (5 arc minutes spatial resolution land and seafloor model), initially developed in 1988 by Margo Edwards, then at Washington University, St. Louis, MO, has been the only global terrain model for a long time, and it is now being replaced by three new topographic and bathymetric DEMs, i.e.; the ETOPO2 (2 arc minutes spatial resolution land and seafloor model), the GTOPO30 land model with a spatial resolution of 30 arc seconds (c.a. 1km at equator) and the 'GEBCO 1-MINUTE GLOBAL BATHYMETRIC GRID' ocean floor model with a spatial resolution of 1 arc minute (c.a. 2 km at equator). These DEMs are products of projects through which compilation and reprocessing of existing and/or new datasets were made to meet user's new requirements. These ongoing efforts are valuable and support should be continued to refine and update these DEMs. On the other hand, a different approach to create a global bathymetric (seafloor) database exists. A method to estimate the seafloor topography from satellite altimetry combined with existing ships' conventional sounding data was devised and a beautiful global seafloor database created and made public by W.H. Smith and D.T. Sandwell in 1997. The big advantage of this database is the uniformity of coverage, i.e. there is no large area where depths are missing. It has a spatial resolution of 2 arc minute. Another important effort is found in making regional, not global, seafloor databases with much finer resolutions in many countries. The Japan Hydrographic Department has compiled and released a 500m-grid topography database around Japan, J-EGG500, in 1999. Although the coverage of this database is only a small portion of the Earth, the database has been highly appreciated in the academic community, and accepted in surprise by the general public when the database was displayed in 3D imagery to show its quality. This database could be rather smoothly combined with the finer land DEM of 250m spatial resolution (Japan250m.grd, K. Kisimoto, 2000). One of the most important applications of this combined DEM of topography and bathymetry is tsunami modeling. Understanding of the coastal environment, management and development of the coastal region are other fields in need of these data. There is, however, an important issue to consider when we create a combined DEM of topography and bathymetry in finer resolutions. The problem arises from the discrepancy of the standard datum planes or reference levels used for topographic leveling and bathymetric sounding. Land topography (altitude) is defined by leveling from the single reference point determined by average mean sea level, in other words, land height is measured from the geoid. On the other hand, depth charts are made based on depth measured from locally determined reference sea surface level, and this value of sea surface level is taken from the long term average of the lowest tidal height. So, to create a combined DEM of topography and bathymetry in very fine scale, we need to avoid this inconsistency between height and depth across the coastal region. Height and depth should be physically continuous relative to a single reference datum across the coast within such new high resolution DEMs. (N.B. Coast line is not equal to 'altitude-zero line' nor 'depth-zero line'. It is defined locally as the long term average of the highest tide level.) All of this said, we still need a lot of work on the ocean side. Global coverage with detailed bathymetric mapping is still poor. Seafloor imaging and other geophysical measurements/experiments should be organized and conducted internationally and interdisciplinary ways more than ever. We always need greater technological advancement

Kisimoto, K.; Hilde, T.

2003-04-01

79

Effect of uncertainty of grid DEM on TOPMODEL: Evaluation and analysis  

Microsoft Academic Search

TOPMODEL, a semi-distributed hydrological model, has been widely used. In the process of simulation of the model, Digital\\u000a Elevation Model (DEM) is used to provide the input data, such as topographic index and distance to the drainage outlet; thus\\u000a DEM plays an important role in TOPMODEL. This study aims at examining the impacts of DEM uncertainty on the simulation results

Peifa Wang; Jinkang Du; Xuezhi Feng; Guoding Kang

2006-01-01

80

Solar DEM Models : A solar image in color band b, mn pixels,  

E-print Network

Solar DEM Models : A solar image in color band b, mÃ?n pixels, containing a particular solar feature, for t = 1, 2, . . . , T. btM sianFieldRandomGaus I M I I bbb T t bbtt bbb bb 2 1 2 )( #12;Solar DEM.bI : the measure error of the ith row and jth column pixel of the certain image in color band b. ijbe #12;Solar DEM

Wolfe, Patrick J.

81

A seamless, high-resolution digital elevation model (DEM) of the north-central California coast  

USGS Publications Warehouse

A seamless, 2-meter resolution digital elevation model (DEM) of the north-central California coast has been created from the most recent high-resolution bathymetric and topographic datasets available. The DEM extends approximately 150 kilometers along the California coastline, from Half Moon Bay north to Bodega Head. Coverage extends inland to an elevation of +20 meters and offshore to at least the 3 nautical mile limit of state waters. This report describes the procedures of DEM construction, details the input data sources, and provides the DEM for download in both ESRI Arc ASCII and GeoTIFF file formats with accompanying metadata.

Foxgrover, Amy C.; Barnard, Patrick L.

2012-01-01

82

DEM generation methods and applications in revealing of topographic changes caused by coal mining activities  

NASA Astrophysics Data System (ADS)

Digital elevation model (DEM) is indispensable for many applications in earth sciences, and there are many kinds of DEM generation methods, such as interpolation between contour lines from topographic maps, stereoscopy from aerial photographs or satellite images, and interferometry from Synthetic Aperture Radar (SAR) data. Due to long years of coal mining activities, topographic changes have happened to Fushun city, northeastern China. In this study, different DEM generation methods of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) stereoscopy, ERS tandem Interferometry Synthetic Aperture Radar (InSAR), and Shuttle Radar Topography Mission (SRTM) InSAR were discussed. Multi-temporal and multi-source DEM data, with different spatial resolutions of 15 m, 40 m and 90 m respectively, were combined to study the topographic changes in the past 10 years caused by open coal mining activities in western Fushun city. ERS InSAR DEM and SRTM DEM data are free of weather conditions, but ASTER DEM quality may be affected by cloud coverage in some local areas. Results from multi-source of DEM data, i.e. ERS InSAR, SRTM and ASTER DEM, show that obvious topographic changes associated with coal mining activities have occurred in Fushun area. The depth of the famous West Open Coal Mine is increasing in the past 10 years, and the maximum depth change is 140 m between 1996 and 2006. Meanwhile, the elevation of three waste rocks piling fields increased more than 10 m due to the coal mining activities.

Dong, Yanfang; Fu, Bihong; Yoshiki, Ninomiya

2008-12-01

83

Improving Cartosat-1 DEM accuracy using synthetic stereo pair and triplet  

NASA Astrophysics Data System (ADS)

Cartosat-1 is the first Indian Remote Sensing Satellite capable of providing along-track stereo images. Cartosat-1 provides forward stereo images with look angles +26° and -5° with respect to nadir for generating Digital Elevation Models (DEMs), Orthoimages and value added products for various applications. A pitch bias of -21° to the satellite resulted in giving reverse tilt mode stereo pair with look angles of +5° and -26° with respect to nadir. This paper compares DEMs generated using forward, reverse and other possible synthetic stereo pairs for two different types of topographies. Stereo triplet was used to generate DEM for Himalayan mountain topography to overcome the problem of occlusions. For flat to undulating topography it was shown that using Cartosat-1 synthetic stereo pair with look angles of -26° and +26° will produce improved version of DEM. Planimetric and height accuracy (Root Mean Square Error (RMSE)) of less than 2.5 m and 2.95 m respectively were obtained and qualitative analysis shows finer details in comparison with other DEMs. For rugged terrain and steep slopes of Himalayan mountain topography simple stereo pairs may not provide reliable accuracies in DEMs due to occlusions and shadows. Stereo triplet from Cartosat-1 was used to generate DEM for mountainous topography. This DEM shows better reconstruction of elevation model even at occluded region when compared with simple stereo pair based DEM. Planimetric and height accuracy (RMSE) of nearly 3 m were obtained and qualitative analysis shows reduction of outliers at occluded region.

Giribabu, D.; Srinivasa Rao, S.; Krishna Murthy, Y. V. N.

2013-03-01

84

Simulation of triaxial response of granular materials by modified DEM  

NASA Astrophysics Data System (ADS)

A modified discrete element method (DEM) with rolling effect taken into consideration is developed to examine macroscopic behavior of granular materials in this study. Dimensional analysis is firstly performed to establish the relationship between macroscopic mechanical behavior, mesoscale contact parameters at particle level and external loading rate. It is found that only four dimensionless parameters may govern the macroscopic mechanical behavior in bulk. The numerical triaxial apparatus was used to study their influence on the mechanical behavior of granular materials. The parametric study indicates that Poisson's ratio only varies with stiffness ratio, while Young's modulus is proportional to contact modulus and grows with stiffness ratio, both of which agree with the micromechanical model. The peak friction angle is dependent on both inter-particle friction angle and rolling resistance. The dilatancy angle relies on inter-particle friction angle if rolling stiffness coefficient is sufficiently large. Finally, we have recommended a calibration procedure for cohesionless soil, which was at once applied to the simulation of Chende sand using a series of triaxial compression tests. The responses of DEM model are shown in quantitative agreement with experiments. In addition, stress-strain response of triaxial extension was also obtained by numerical triaxial extension tests.

Wang, XiaoLiang; Li, JiaChun

2014-12-01

85

Integration of SAR and DEM data: Geometrical considerations  

NASA Technical Reports Server (NTRS)

General principles for integrating data from different sources are derived from the experience of registration of SAR images with digital elevation models (DEM) data. The integration consists of establishing geometrical relations between the data sets that allow us to accumulate information from both data sets for any given object point (e.g., elevation, slope, backscatter of ground cover, etc.). Since the geometries of the two data are completely different they cannot be compared on a pixel by pixel basis. The presented approach detects instances of higher level features in both data sets independently and performs the matching at the high level. Besides the efficiency of this general strategy it further allows the integration of additional knowledge sources: world knowledge and sensor characteristics are also useful sources of information. The SAR features layover and shadow can be detected easily in SAR images. An analytical method to find such regions also in a DEM needs in addition the parameters of the flight path of the SAR sensor and the range projection model. The generation of the SAR layover and shadow maps is summarized and new extensions to this method are proposed.

Kropatsch, Walter G.

1991-01-01

86

DEM, tide and velocity over sulzberger ice shelf, West Antarctica  

USGS Publications Warehouse

Arctic and Antarctic ice sheets preserve more than 77% of the global fresh water and could raise global sea level by several meters if completely melted. Ocean tides near and under ice shelves shifts the grounding line position significantly and are one of current limitations to study glacier dynamics and mass balance. The Sulzberger ice shelf is an area of ice mass flux change in West Antarctica and has not yet been well studied. In this study, we use repeat-pass synthetic aperture radar (SAR) interferometry data from the ERS-1 and ERS-2 tandem missions for generation of a high-resolution (60-m) Digital Elevation Model (DEM) including tidal deformation detection and ice stream velocity of the Sulzberger Ice Shelf. Other satellite data such as laser altimeter measurements with fine foot-prints (70-m) from NASA's ICESat are used for validation and analyses. The resulting DEM has an accuracy of-0.57??5.88 m and is demonstrated to be useful for grounding line detection and ice mass balance studies. The deformation observed by InSAR is found to be primarily due to ocean tides and atmospheric pressure. The 2-D ice stream velocities computed agree qualitatively with previous methods on part of the Ice Shelf from passive microwave remote-sensing data (i.e., LANDSAT). ?? 2005 IEEE.

Baek, S.; Shum, C.K.; Lee, H.; Yi, Y.; Kwoun, O.-I.; Lu, Z.; Braun, A.

2005-01-01

87

Extraction of Hydrological Proximity Measures from DEMs using Parallel Processing  

SciTech Connect

Land surface topography is one of the most important terrain properties which impact hydrological, geomorphological, and ecological processes active on a landscape. In our previous efforts to develop a soil depth model based upon topographic and land cover variables, we extracted a set of hydrological proximity measures (HPMs) from a Digital Elevation Model (DEM) as potential explanatory variables for soil depth. These HPMs may also have other, more general modeling applicability in hydrology, geomorphology and ecology, and so are described here from a general perspective. The HPMs we derived are variations of the distance up to ridge points (cells with no incoming flow) and variations of the distance down to stream points (cells with a contributing area greater than a threshold), following the flow path. These HPMs were computed using the D-infinity flow model that apportions flow between adjacent neighbors based on the direction of steepest downward slope on the eight triangular facets constructed in a 3 x 3 grid cell window using the center cell and each pair of adjacent neighboring grid cells in turn. The D-infinity model typically results in multiple flow paths between 2 points on the topography, with the result that distances may be computed as the minimum, maximum or average of the individual flow paths. In addition, each of the HPMs, are calculated vertically, horizontally, and along the land surface. Previously, these HPMs were calculated using recursive serial algorithms which suffered from stack overflow problems when used to process large datasets, limiting the size of DEMs that could be analyzed using that method to approximately 7000 x 7000 cells. To overcome this limitation, we developed a message passing interface (MPI) parallel approach for calculating these HPMs. The parallel algorithms of the HPMs spatially partition the input grid into stripes which are each assigned to separate processes for computation. Each of those processes then uses a queue data structure to order the processing of cells so that each cell is visited only once and the cross-process communications that are a standard part of MPI are handled in an efficient manner. This parallel approach allows analysis of much larger DEMs as compared to the serial recursive algorithms. In this paper, we present the definitions of the HPMs, the serial and parallel algorithms used in their extraction and their potential applications in hydrology, geomorphology and ecology.

Tesfa, Teklu K.; Tarboton, David G.; Watson, Daniel W.; Schreuders, Kimberly A.; Baker, Matthew M.; Wallace, Robert M.

2011-12-01

88

Near-automatic generation of lava dome DEMs from photos  

NASA Astrophysics Data System (ADS)

Acquiring accurate digital elevation models (DEMs) of growing lava domes is critical for hazard assessment. However, most techniques require expertise and time (e.g. photogrammetry) or expensive equipment (e.g. laser scanning and radar-based techniques). Here, we use a photo-based approach developed within the computer vision community that offers the potential for near-automatic DEM construction using a consumer-grade digital camera and freely available software. The technique is based on a combination of structure-from-motion and multi-view stereo algorithms (SfM-MVS) and can generate dense 3D point clouds (millions of points) from multiple photographs of a scene taken from different positions. Processing is carried out by automated 'reconstruction pipeline' software downloadable from the internet, e.g. http://blog.neonascent.net/archives/bundler-photogrammetry-package/. Such reconstructions are initally un-scaled and un-oriented so additional software (http://www.lancs.ac.uk/ staff/jamesm/software/sfm_georef.htm) has been developed to permit scaling or full georeferencing. Although this step requires the presence of some control points or knowledge of scale within the scene, it does not have the relatively strict image acquisition and control requirements of traditional photogrammetry. For accuracy and to allow error analysis, georeferencing observations are made within the image set, rather than requiring feature matching within the point cloud. Here we demonstrate the results of using the technique for deriving 3D models of the Volcán de Colima lava dome. 5 image sets have been collected by different people over a period of 12 months during overflights in a light aircraft. Although the resulting imagery is of variable quality for 3D reconstruction, useful data can be extracted from each set. Scaling and georeferencing is carried out using a combination of ortho-imagery (downloaded from Bing) and a few GPS points. Overall precisions are ~1 m and DEM qualities are sufficient to quantify dome loss and talus gain from small rockfall sites, as well as to highlight the structural evolution of the upper surface of the dome as it collapses.

James, M. R.; Varley, N.

2012-04-01

89

DEM resolution effects on shallow landslide hazard and soil redistribution modelling  

Microsoft Academic Search

In this paper we analyse the effects of digital elevation model (DEM) resolution on the results of a model that simulates spatially explicit relative shallow landslide hazard and soil redistribution patterns and quantities. We analyse distributions of slope, specific catchment area and relative hazard for shallow landsliding for four different DEM resolutions (grid sizes of 10, 25, 50 and 100

L. F. G. Claessens; G. B. M. Heuvelink; J. M. Schoorl; A. Veldkamp

2005-01-01

90

Tau auf dem Bei Alzheimer-Forschung denkt man nicht unbedingt an Teilchenbeschleuniger. Das Deutsche  

E-print Network

Tau auf dem Gedächtnis Bei Alzheimer-Forschung denkt man nicht unbedingt an Teilchenbeschleuniger. Neben dem Verlust an Nervenzellen In einer gesunden Nervenzelle stabilisiert das tau-Protein (rot) das Zellskelett im Axon der Zelle (1). In einer Zelle mit einem zusätzlichen tau-Gen, das schnell verklumpendes

Spang, Rainer

91

DEM GENERATION FROM ASTER SATELLITE DATA FOR GEOMORPHOMETRIC ANALYSIS OF CERRO SILLAJHUAY, CHILE/BOLIVIA  

E-print Network

DEM GENERATION FROM ASTER SATELLITE DATA FOR GEOMORPHOMETRIC ANALYSIS OF CERRO SILLAJHUAY, CHILE@data.unomaha.edu ABSTRACT Digital elevation models (DEMs) are increasingly used for visual and mathematical analysis are useful to identify and describe geomorphologic forms and processes, were extracted using the software Arc

Bolch, Tobias

92

The Global SRTM X-SAR DEM - Calibration, Validation, Production Status and Results  

Microsoft Academic Search

In February 2000, the Shuttle Radar Topography Mission (SRTM) acquired a global digital elevation model (DEM) within only 11 days. Extensive testing and calibration activities primarily based on ocean surface data took place at DLR during the years 2000 and 2001. The calibration phase is now finished and the quality of the DEMs analyzed so far met all specifications. The

Nico Adam; Helko Breit; Walter Knöpfle; M. Einede; Steffen Suchandt

2003-01-01

93

Application of the PROMETHEE technique to determine depression outlet location and flow direction in DEM  

Microsoft Academic Search

With the fast growing progress of computer technologies, spatial information on watersheds such as flow direction, watershed boundaries and the drainage network can be automatically calculated or extracted from a digital elevation model (DEM). The stubborn problem that depressions exist in DEMs has been frequently encountered while extracting the spatial information of terrain. Several filling-up methods have been proposed for

Tien-Yin Chou; Wen-Tzu Lin; Chao-Yuan Lin; Wen-Chieh Chou; Pi-Hui Huang

2004-01-01

94

Solar DEM Model Proposal : A solar image in color band b, mn pixels,  

E-print Network

Solar DEM Model Proposal : A solar image in color band b, m�n pixels, containing a particular solar 11 )( #12;Solar DEM Model Proposal : the volume (abundance?) of ion ii : the proportion of the total volume at temperature t t T t bitt I i ib MIE 11 )( #12;Solar Dataset · 15 Filters.txt files

Wolfe, Patrick J.

95

Using ASTER and SRTM DEMs for studying geomorphology and glaciation in high mountain areas  

E-print Network

Using ASTER and SRTM DEMs for studying geomorphology and glaciation in high mountain areas Tobias, SRTM, geomorphology, glaciation, Andes, Hindu Kush, Tien Shan ABSTRACT: For selected peaks in high identifying debris-covered glaciers and geomorphologic forms and processes. Results show that ASTER/SRTM DEMs

Bolch, Tobias

96

Calculating the trajectories of triboelectrically charged particles using Discrete Element Modeling (DEM)  

Microsoft Academic Search

Theoretical and experimental work has been performed pursuant to incorporating electrostatic forces into a commercial Discrete Element Modeling (DEM) software package. This DEM software is used to model the trajectories of large numbers of particles for industrial applications and processes. Electrostatic forces due to the triboelectrification of the particles will be included in the model in addition to existing kinematic

Michael D. Hogue; Carlos I. Calle; Peter S. Weitzman; David R. Curry

2008-01-01

97

A Comparative Study of Radar Stereo and Interferometry for DEM Generation  

NASA Astrophysics Data System (ADS)

In this experiment, we derive and compare radar stereo and interferometric elevation models (DEMs) of a study site in Djibouti, East Africa. As test data, we use a Radarsat stereo pair and ERS-2 and Radarsat interferometric data. Comparison of the reconstructed DEMs with a SPOT reference DEM shows that in regions of high coherence the DEMs produced by interferometry are of much better quality than the stereo result. However, the interferometric error histograms also show some pronounced outliers due to decorrelation and phase unwrapping problems on forested mountain slopes. The more robust stereo result is able to capture the general terrain shape, but finer surface details are lost. A fusion experiment demonstrates that merging the stereoscopic and interferometric DEMs by utilizing coherence- derived weights can significantly improve the accuracy of the computed elevation maps.

Gelautz, M.; Paillou, P.; Chen, C. W.; Zebker, H. A.

2004-06-01

98

Time series analysis of the relationship between private consumer expenditure and disposable personal income for the case of Austria  

Microsoft Academic Search

In der vorliegenden Arbeit werden Verfahren der Zeitreihenanalyse zur Untersuchung des Zusammenhangs zwischen Konsum und Einkommen herangezogen. In der theoretischen Literatur wird die Existenz eines derartigen Zusammenhangs ja seit Jahrzehnten unterstellt. Die empirische Verifikation dieser evidenten Kausalbeziehung hat sich jedoch als sehr schwierig herausgestellt. Vor allem die Prognosefähigkeit der zahlreich geschätzten Regressionsgleichungen läßt zu wünschen übrig. Dies dürfte darauf zurückgehen,

Gerhard Thury

1980-01-01

99

Morphological changes at Mt. Etna detected by TanDEM-X  

NASA Astrophysics Data System (ADS)

We produced a DEM of the Mt. Etna volcano using TanDEM-X data collected on October 9, 2012. The TanDEM-X data were acquired in bistatic mode with TSX as master sensor and TDX as receive only sensor. The pre-existing SRTM DEM was used for geometrical reference (geocoding, initial height model, large scale reference). The interferogram was computed with 4 looks in range and 4 looks in azimuth. After compensation of the SRTM heights, the differential TanDEM-X interferogram looked overall quite flat but showed local deviations related to noise (e.g. over the sea), topographic effects related to the low resolution of the SRTM DEM, and deviations related to actual changes of the topography, as observed in the Mount Etna peak region. After phase unwrapping, addressed with a minimum-cost flow algorithm and slight spatial filtering, the unwrapped phases were converted to relative heights. In order to move to absolute heights the SRTM height reference was used under the assumption that the deviation from the SRTM DEM is zero at large scale and without any linear trend. Finally, the height model was resampled into geographical coordinates. In the framework of the MED-SUV project, and thanks to the availability of a dense GPS network of more than 100 benchmarks periodically measured by INGV_OE, the TanDEM-X model has been validated. By computing the difference of the elevations provided by TanDEM-X with those measured by GPS we obtained a mean difference of 0.7 m and a standard deviation of 5.2 m. These values are biased by a few GPS benchmarks located in steep areas unfavorable illuminated by the radar. Without considerations of the two more unfavorable GPS stations, the height mean difference and a standard deviation are 0.6 m and 4.3 m respectively. We also performed correlation analyses of the height differences with respect to topography, latitude and longitude and we could exclude any elevation-related errors or geometrical ramp distortions. In the following, we compared the 2012 TanDEM-X model with the 2000 SRTM DEM in order to evaluate the morphological changes occurred on the volcano during the 12 years time lap. The pixel size of SRTM-DEM is about 90 m and we resampled the TanDEM-X model to fit this value. The results show that most of the variations occurred in the Valle del Bove and on the summit crater areas. In order to compare DEMs with the same pixel size, we performed a further comparison with a 5m ground resolution optical DEM, produced in 2004 and covering only the summit area. The variations in topography have been compared with ground mapping surveys, confirming a good correlation with the spatial extension of the lava flows and of the pyroclastic deposits occurred on Mt. Etna in the last seven years. The comparison between the two DEM's (2004-2012) allows calculating the amount of volcanics emitted and to clearly monitoring the growth and development of the New South East Crater (NSEC). TanDEM-X is a useful tools to monitor volcanic area characterized by a quit frequent activity (a paroxysm every 5-10 days), such us Mt. Etna, especially if concentrated in areas not easily accessible.

Wegmuller, Urs; Bonforte, Alessandro; De Beni, Emanuela; Guglielmino, Francesco; Strozzi, Tazio

2014-05-01

100

Grain sedimentation with SPH-DEM and its validation  

NASA Astrophysics Data System (ADS)

Our mesoscale simulation method [M. Robinson, S. Luding, and M. Ramaioli, submitted (2013)] for multiphase fluid-particle flows couples Smoothed Particle Hydrodynamics (SPH) and the Discrete Element Method (DEM) and enjoys the flexibility of meshless methods, such as being capable to handling free surface flows or flow around complex and/or moving geometries. We use this method to simulate three different sedimentation test cases and compare the results to existing analytical solutions. The grain velocity in Single Particle Sedimentation compares well (< 2% error) with the analytical solution as long as the fluid resolution is coarser than two times the particle diameter. The multiple particle sedimentation problem and Rayleigh Taylor Instability (RTI) also perform well against the theory, but it was found that the method is susceptible to fluid velocity fluctuations in the presence of high porosity gradients. These fluctuations can be damped by the addition of a dissipation term, which has no effect on the terminal velocity but can lead to slower growth rates for the RTI.

Robinson, Martin; Luding, Stefan; Marco Ramaioli, Marco

2013-06-01

101

SPH-DEM simulations of grain dispersion by liquid injection  

NASA Astrophysics Data System (ADS)

We study the dispersion of an initially packed, static granular bed by the injection of a liquid jet. This is a relevant system for many industrial applications, including paint dispersion or food powder dissolution. Both decompaction and dispersion of the powder are not fully understood, leading to inefficiencies in these processes. Here we consider a model problem where the liquid jet is injected below a granular bed contained in a cylindrical cell. Two different initial conditions are considered: a two-phase case where the bed is initially fully immersed in the liquid and a three-phase case where the bed and cell are completely dry preceding the injection of the liquid. The focus of this contribution is the simulation of these model problems using a two-way coupled SPH-DEM granularliquid method [M. Robinson, M. Ramaioli, and S. Luding, submitted (2013) and http://arxiv.org/abs/1301.0752 (2013)]. This is a purely particle-based method without any prescribed mesh, well suited for this and other problems involving a free (liquidgas) surface and a partly immersed particle phase. Our simulations show the effect of process parameters such as injection flow rate and injection diameter on the dispersion pattern, namely whether the granular bed is impregnated bottom-up or a jet is formed and compare well with experiments.

Robinson, Martin; Luding, Stefan; Ramaioli, Marco

2013-06-01

102

Investigation of the Critical State in Soil Mechanics Using DEM  

SciTech Connect

The existence and uniqueness of the so-called critical state in soil mechanics is validated in our DEM simulations of irregular polygonal particles. For different particle shape characteristics, the critical state is independent of the initial stress and density conditions. We retain low stress levels, since we do not take into account the crushing of particles. In biaxial test simulations isotropic particles evolve toward a limiting state in which the system reaches a critical void ratio and deforms with constant volume, deviatoric stress, fabric anisotropy, and mechanical coordination number. The last one has been found to be the first variable to attain a critical value making possible for the rest of micro-and-macro-mechanical variables the convergence to the critical state. In periodic shear cell tests, for large shear deformations samples with anisotropic particles reach at the macro-mechanical level the same critical value for both shear force and void ratio. At the micro-mechanical level the components of the stress tensor, the fabric tensor and the inertia tensor of the particles also reach the same stationary state. By varying the aspect ratio of the particles we stated the strong influence of particle shape anisotropy on the parameters that the granular packing attained at the critical state.

Pena, Andres A. [Bilfinger Berger GmbH, Gustav-Nachtigal 3, 65915 Wiesbaden (Germany); ICP, University of Stuttgart, Pfaffenwaldring 27, D-70569 Stuttgart (Germany); Garcia-Rojo, Ramon [EPCOS, Avda. Jose Ortega y Gasset 173, 29006 Malaga (Spain); Alonso-Marroquin, Fernando [MoSCoS, School of Mathematics and Physics, University of Queensland, St. Lucia, Qld. 4067 (Australia); Herrmann, Hans J. [Departamento de Fisica, Universidade Federal do Ceara, 60451-970 Fortaleza, Ceara (Brazil); Computational Physics, IfB, HIF E12, ETH Hoenggerberg, CH-8093 Zuerich (Switzerland)

2009-06-18

103

Evaluation of DEM generation accuracy from UAS imagery  

NASA Astrophysics Data System (ADS)

The growing use of UAS platform for aerial photogrammetry comes with a new family of Computer Vision highly automated processing software expressly built to manage the peculiar characteristics of these blocks of images. It is of interest to photogrammetrist and professionals, therefore, to find out whether the image orientation and DSM generation methods implemented in such software are reliable and the DSMs and orthophotos are accurate. On a more general basis, it is interesting to figure out whether it is still worth applying the standard rules of aerial photogrammetry to the case of drones, achieving the same inner strength and the same accuracies as well. With such goals in mind, a test area has been set up at the University Campus in Parma. A large number of ground points has been measured on natural as well as signalized points, to provide a comprehensive test field, to check the accuracy performance of different UAS systems. In the test area, points both at ground-level and features on the buildings roofs were measured, in order to obtain a distributed support also altimetrically. Control points were set on different types of surfaces (buildings, asphalt, target, fields of grass and bumps); break lines, were also employed. The paper presents the results of a comparison between two different surveys for DEM (Digital Elevation Model) generation, performed at 70 m and 140 m flying height, using a Falcon 8 UAS.

Santise, M.; Fornari, M.; Forlani, G.; Roncella, R.

2014-06-01

104

Penetration strength of coarse granular materials from DEM simulations  

NASA Astrophysics Data System (ADS)

Field tests are widely used for soil characterization in geotechnical applications in spite of implementation difficulties. The light penetrometer test is a well-known testing tool for fine soils, but the physical interpretation of the output data in the case of coarse granular materials is far less evident. In fact, the data are considerably more sensitive to various parameters such as fabric structure, particles shape or the applied impact energy. In order to achieve a better understanding of the underlying phenomena, we performed a numerical study by means contact dynamics DEM simulations. We consider the penetration of a moving tip into a sample composed of irregular grain shapes and we analyze the influence of the driving velocity and applied energy on the penetration strength. We find that the latter grows with both the penetration rate and energy. Force fluctuations on the tip involve a jamming-unjamming process. The typology of contact network and inter-granular friction play a major role in the fluctuations and measured values of the cone penetration strength.

Quezada, Juan Carlos; Saussine, Gilles; Breul, Pierre; Radjai, Farhang

2013-06-01

105

TecDEM: A MATLAB based toolbox for tectonic geomorphology, Part 1: Drainage network preprocessing and stream profile analysis  

NASA Astrophysics Data System (ADS)

We present TecDEM, a software shell implemented in MATLAB that applies tectonic geomorphologic tasks to digital elevation models (DEMs). The first part of this paper series describes drainage partitioning schemes and stream profile analysis. The graphical user interface of TecDEM provides several options: determining flow directions, stream vectorization, watershed delineation, Strahler order labeling, stream profile generation, knickpoints selection, Concavity, Steepness and Hack indices calculations. The knickpoints along selected streams as well as stream profile analysis, and Hack index per stream profile are computed using a semi-automatic method. TecDEM was used to extract and investigate the stream profiles in the Kaghan Valley (Northern Pakistan). Our interpretations of the TecDEM results correlate well with previous tectonic evolution models for this region. TecDEM is designed to assist geoscientists in applying complex tectonic geomorphology tasks to global DEM data.

Shahzad, Faisal; Gloaguen, Richard

2011-02-01

106

What is the effect of LiDAR-derived DEM resolution on large-scale watershed model results?  

SciTech Connect

This paper examines the effect of raster cell size on hydrographic feature extraction and hydrological modeling using LiDAR derived DEMs. LiDAR datasets for three experimental watersheds were converted to DEMs at various cell sizes. Watershed boundaries and stream networks were delineated from each DEM and were compared to reference data. Hydrological simulations were conducted and the outputs were compared. Smaller cell size DEMs consistently resulted in less difference between DEM-delineated features and reference data. However, minor differences been found between streamflow simulations resulted for a lumped watershed model run at daily simulations aggregated at an annual average. These findings indicate that while higher resolution DEM grids may result in more accurate representation of terrain characteristics, such variations do not necessarily improve watershed scale simulation modeling. Hence the additional expense of generating high resolution DEM's for the purpose of watershed modeling at daily or longer time steps may not be warranted.

Ping Yang; Daniel B. Ames; Andre Fonseca; Danny Anderson; Rupesh Shrestha; Nancy F. Glenn; Yang Cao

2014-08-01

107

Hybrid MPI/GPU Interpolation for Grid DEM Construction Andrew Danner  

E-print Network

provide geomorphological advantages over simpler interpolation methods such as lin- ear interpolation elevation model (DEM) from the lidar points and run analysis on the digi- tal elevation model. The extremely

Danner, Andrew

108

DEM automatic extraction on Rio de Janeiro from WV2 stereo pair images  

NASA Astrophysics Data System (ADS)

The use of three-dimensional data has become, for a lot of mapping applications, very important. DEM are applied for modelling purposes, i.e. the 3D city model generation, but principally for imagery orthorectification. In aerial photogrammetry is well known the suitable use of stereo imagery to produce an accurate DEM, but the limits of the process (cost, schedule of data collection, highly technical staff) and the new advanced digital image processing algorithms have open the work scenario to the remote sensing data. This research has wanted to investigate the possibility to obtain accurate DEMs by means of automatic terrain extraction algorithms implemented in Leica Photogrammetry Suite (LPS) from stereoscopic remote sensing images collected by DigitalGlobe's WorldView-2 (WV2) satellite. The DEM of Rio de Janeiro (Brazil) and the correspondent digital orthoimages have been the results.

Malinverni, E. S.

2014-02-01

109

Error analysis of DEM derived from airborne single-pass interferometric SAR data  

Microsoft Academic Search

The main objective of this paper is to examine and evaluate the performance of the airborne SAR system through interferometric processing and error analysis. Firstly, the paper describes how high-precision DEMs are derived from the airborne dual-antenna InSAR data. Based on airborne dual-antenna InSAR bore-sight model, this paper summarizes the main factors which influence the accuracy of DEM in data

Zhongchang Sun; Huadong Guo; Xinwu Li; Mengmei Jiao

2011-01-01

110

Uncertainty of SWAT model at different DEM resolutions in a large mountainous watershed.  

PubMed

The objective of this study was to enhance understanding of the sensitivity of the SWAT model to the resolutions of Digital Elevation Models (DEMs) based on the analysis of multiple evaluation indicators. The Xiangxi River, a large tributary of Three Gorges Reservoir in China, was selected as the study area. A range of 17 DEM spatial resolutions, from 30 to 1000 m, was examined, and the annual and monthly model outputs based on each resolution were compared. The following results were obtained: (i) sediment yield was greatly affected by DEM resolution; (ii) the prediction of dissolved oxygen load was significantly affected by DEM resolutions coarser than 500 m; (iii) Total Nitrogen (TN) load was not greatly affected by the DEM resolution; (iv) Nitrate Nitrogen (NO?-N) and Total Phosphorus (TP) loads were slightly affected by the DEM resolution; and (v) flow and Ammonia Nitrogen (NH?-N) load were essentially unaffected by the DEM resolution. The flow and dissolved oxygen load decreased more significantly in the dry season than in the wet and normal seasons. Excluding flow and dissolved oxygen, the uncertainties of the other Hydrology/Non-point Source (H/NPS) pollution indicators were greater in the wet season than in the dry and normal seasons. Considering the temporal distribution uncertainties, the optimal DEM resolutions for flow was 30-200 m, for sediment and TP was 30-100 m, for dissolved oxygen and NO?-N was 30-300 m, for NH?-N was 30 to 70 m and for TN was 30-150 m. PMID:24509347

Zhang, Peipei; Liu, Ruimin; Bao, Yimeng; Wang, Jiawei; Yu, Wenwen; Shen, Zhenyao

2014-04-15

111

Monitoring lava dome changes by means of differential DEMs from TanDEM-X interferometry: Examples from Merapi, Indonesia and Volcán de Colima, Mexico  

NASA Astrophysics Data System (ADS)

Estimating the amount of erupted material during a volcanic crisis is one of the major challenges in volcano research. One way to do this and to discriminate between juvenile and non-juvenile fraction is to assess topographic changes before and after an eruption while using area-wide 3D data. LiDAR or other airborne systems may be a good source, but the recording fails when clouds due to volcanic activity obstruct the sight. In addition, costs as well as logistics are high for local observatories. When dealing with dome-building volcanoes, acquiring the data gets further complicated. As the volcano dome can change rapidly in active phases, it is nearly impossible to collect data at the right time. However, when dealing with gross volume change estimates, at least two data sets - taken directly before and after the eruption - are essential. The innovative German Earth observation mission TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement) is of great importance to overcome some of these problems. The two almost identical radar satellites TerraSAR-X and TanDEM-X fly in a close formation, thus recording images of the same place on the Earth surface at the same time (bistatic mode). As the radar signal penetrates clouds, digital elevation models (DEMs) of the area of investigation can be generated without problems even with cloud cover. A time series analysis of the differential DEMs therefore opens the possibility to assess volume changes at active lava domes. We choose Merapi in Indonesia and Volcán de Colima in Mexico as test sites. Both volcanoes reside in a state of long term effusive eruption, interrupted every few years by phases of dome destruction, generation of pyroclastic flows and deposition of volcanic material. The availability of extensive ground truth data for both test sites further enables to validate the spaceborne data and results. Here, we analyze lava dome changes due to the hazardous Merapi 2010 eruption. We show a series of DEMs derived by TanDEM-X interferometry taken before and after the eruption. Our results reveal that the eruption had led to a topographic change of up to 200 m in the summit area of Merapi. We further show the ability of the TanDEM-X data to observe much smaller topographic changes using Volcán de Colima as second test site. An explosion at the crater rim signaled the end of magma ascent in June 2011. The bistatic TanDEM-X data give important information on this explosion as we can observe topographic changes of up to 20 m and less in the summit area when comparing datasets taken before and after the event. We further analyzed datasets from the beginning of the year 2013 when Colima got active again after a dormant period. Our results indicate that repeated DEMs with great detail and good accuracy are obtainable, enabling a quantitative estimation of volume changes in the summit area of the volcano. As the TanDEM-X mission is an innovative mission, the present study serves as a test to employ data of a new satellite mission in volcano research. An error analysis of the DEMs to evaluate the volume quantifications was therefore also conducted.

Kubanek, J.; Westerhaus, M.; Heck, B.

2013-12-01

112

ASTER Global DEM contribution to GEOSS demonstrates open data sharing  

NASA Astrophysics Data System (ADS)

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) remote sensing instrument on the Terra spacecraft has been acquiring images of Earth since launch in 1999. Throughout this time data products have been openly available to the general public through sites in the U.S. and Japan. As the ASTER mission matured, a spatially broad and temporally deep data archive was gradually established. With this extensive accumulation of Earth observations, it became possible to create a new global digital elevation product, the ASTER Global Digital Elevation Model (GDEM), using multi-temporal data, resulting in over 22,000 static 10 X 10 tiles. The ASTER GDEM was contributed by Japan’s Ministry of Economy Trade and Industry (METI) and the U.S. National Aeronautics and Space Administration (NASA) to the Global Earth Observation System of Systems (GEOSS) for distribution at no cost to users. As such, both METI and NASA desired to understand the uses of the ASTER GDEM, expressed as one of the GEOSS applications themes: disasters, health, energy, climate, water, weather, ecosystems, agriculture or biodiversity. This required both the registration of users, and restrictions on redistribution, to capture the intended use in terms of the GEOSS themes. The ASTER GDEM was made available to users worldwide via electronic download from the Earth Remote Sensing Data Analysis Center (ERSDAC) of Japan and from NASA’s Land Processes Distributed Active Archive Center (LP DAAC). During the first three months after product release, over 4 million GDEM tiles were distributed from the LP DAAC and ERSDAC. The ASTER GDEM release generated nearly 20,000 new user registrations in the NASA EOS ClearingHOuse (ECHO)/WIST and the ERSDAC systems. By the end of 2009, over 6.5 Million GDEM tiles were distributed by the LP DAAC and ERSDAC. Users have requested tiles over specific areas of interest as well as the entire dataset for global research. Intense global interest in the GDEM across all the GEOSS Societal Benefit areas was shown. The release of the global tiled research-grade DEM resulted in a significant increase in demand for ASTER elevation models, and increased awareness of related products. No cost access to these data has also promoted new applications of remotely sensed data, increasing their use across the full range of the GEOSS societal benefit areas. In addition, the simplified data access and greatly expanded pool of users resulted in a number of suggestions from researchers in many disciplines for possible enhancements to future versions of the ASTER GDEM. The broad distribution of the product can be directly attributed to the adoption of fundamental GEOSS data sharing principles, which are directed toward expanded access by minimizing time delay and cost, thus facilitating data use for education, research, and a range of other applications. The ASTER GDEM demonstrated the need and user demand for an improved global DEM product as well as the added benefit of not only “full and open” distribution, but “free and open” distribution.

Sohre, T.; Duda, K. A.; Meyer, D. J.; Behnke, J.; Nasa Esdis Lp Daac

2010-12-01

113

HELI-DEM portal for geo-processing services  

NASA Astrophysics Data System (ADS)

HELI-DEM (Helvetia-Italy Digital Elevation Model) is a project developed in the framework of Italy/Switzerland Operational Programme for Trans-frontier Cooperation 2007-2013 whose major aim is to create a unified digital terrain model that includes the alpine and sub-alpine areas between Italy and Switzerland. The partners of the project are: Lombardy Region, Piedmont Region, Polytechnic of Milan, Polytechnic of Turin and Fondazione Politecnico from Italy; Institute of Earth Sciences (SUPSI) from Switzerland. The digital terrain model has been produced by integrating and validating the different elevation data available for the areas of interest, characterized by different reference frame, resolutions and accuracies: DHM at 25 m resolution from Swisstopo, DTM at 20 m resolution from Lombardy Region, DTM at 5 m resolution from Piedmont Region and DTM LiDAR PST-A at about 1 m resolution, that covers the main river bed areas and is produced by the Italian Ministry of the Environment. Further results of the project are: the generation of a unique Italian Swiss geoid with an accuracy of few centimeters (Gilardoni et al. 2012); the establishment of a GNSS permanent network, prototype of a transnational positioning service; the development of a geo-portal, entirely based on open source technologies and open standards, which provides the cross-border DTM and offers some capabilities of analysis and processing through the Internet. With this talk, the authors want to present the main steps of the project with a focus on the HELI-DEM geo-portal development carried out by the Institute of Earth Sciences, which is the access point to the DTM outputted from the project. The portal, accessible at http://geoservice.ist.supsi.ch/helidem, is a demonstration of open source technologies combined for providing access to geospatial functionalities to wide non GIS expert public. In fact, the system is entirely developed using only Open Standards and Free and Open Source Software (FOSS) both on the server side (services) and on the client side (interface). In addition to self developed code the system relies mainly on teh software GRASS 7 [1], ZOO-project [2], Geoserver [3] and OpenLayers [4] and the standards WMS [5], WCS [6] and WPS [7]. At the time of writing, the portal offers features like profiling, contour extraction, watershed delineation and analysis, derivatives calculation, data extraction, coordinate conversion but it is evolving and it is planned to extend to a series of environmental modeling that the IST developed in the past like dam break simulation, landslide run-out estimation and floods due to landslide impact in artificial basins. [1] Neteler M., Mitasova H., Open Source GIS: A GRASS GIS Approach. 3rd Ed. 406 pp, Springer, New York, 2008. [2] Fenoy G., Bozon N., Raghavan V., ZOO Project: The Open Wps Platform. Proceeding of 1st International Workshop on Pervasive Web Mapping, Geoprocessing and Services (WebMGS). Como, http://www.isprs.org/proceedings/XXXVIII/4-W13/ID_32.pdf, 26-27 agosto 2010. [3] Giannecchini S., Aime A., GeoServer, il server open source per la gestione interoperabile dei dati geospaziali. Atti 15a Conferenza Nazionale ASITA. Reggia di Colorno, 15-18 novembre 2011. [4] Perez A.S., OpenLayers Cookbook. Packt Publishing, 2012. ISBN 1849517843. [5] OGC, OpenGIS Web Map Server Implementation Specification, http://www.opengeospatial.org/standards/wms, 2006. [6] OGC, OGC WCS 2.0 Interface Standard - Core, http://portal.opengeospatial.org/files/?artifact_id=41437, 2010b. [7] OGC, OpenGIS Web Processing Service, http://portal.opengeospatial.org/files/?artifact_id=24151, 2007.

Cannata, Massimiliano; Antonovic, Milan; Molinari, Monia

2014-05-01

114

ALOS DEM quality assessment in a rugged topography, A Lebanese watershed as a case study  

NASA Astrophysics Data System (ADS)

Deriving the morphometric descriptors of the Earth's surface from satellite images is a continuing application in remote sensing, which has been distinctly pushed with the increasing availability of DEMs at different scales, specifically those derived from high to very high-resolution stereoscopic and triscopic image data. The extraction of the morphometric descriptors is affected by the errors of the DEM. This study presents a procedure for assessing the quality of ALOS DEM in terms of position and morphometric indices. It involves evaluating the impact of the production parameters on the altimetric accuracy through checking height differences between Ground Control Points (GCP) and the corresponding DEM points, on the planimetric accuracy by comparing extracted drainage lines with topographic maps, and on the morphometric indices by comparing profiles extracted from the DEM with those measured on the field. A twenty set of triplet-stereo imagery from the PRISM instrument on the ALOS satellite has been processed to acquire a 5 m DEM covering the whole Lebanese territories. The Lebanese topography is characterized by its ruggedness with two parallel mountainous chains embedding a depression (The Bekaa Valley). The DEM was extracted via PCI Geomatica 2013. Each of the images required 15 GCPs and around 50 tie points. Field measurements was carried out using differential GPS (Trimble GeoXH6000, ProXRT receiver and the LaserACE 1000 Rangefinder) on Al Awali watershed (482 km2, about 5% of the Lebanese terrain). 3545 GPS points were collected at all ranges of elevation specifying the Lebanese terrain diversity, ranging from cliffy, to steep and gently undulating terrain along with narrow and wide flood plains and including predetermined profiles. Moreover, definite points such as road intersections and river beds were also measured in order to assess the extracted streams from the DEM. ArcGIS 10.1 was also utilized to extract the drainage network. Preliminary results showed that using Toutin's Model, enabling Wallis filter and specifying high DEM detail, along with restricting the holes filling option gave the best position accuracy and the least number of failure values. This is mainly due to the ruggedness of the studying area. Comparing GPS heights with the extract DEM showed a Minimum and a maximum error of (-11.9 m, 10.56 m), Mean error (1.32 m) and RMSE of (4.7 m). While extracting the drainage lines showed 80 to 90 % of coincidence of the upper water heads and an order of less than one pixel for the main river course and mountainous road intersection.

Abdallah, Chadi; El Hage, Mohamad; Termos, Samah; Abboud, Mohammad

2014-05-01

115

Uber Phosphorylierung im Licht  

PubMed Central

Während bisher der Zusammenhang zwischen Dehydrierung und Phosphorylierung im Licht nur für die stöchiometrischen Chinonreactionen bewiesen worden war, ist nunmehr auch für die katalytischen Chinonreactionen, die aeroben wie die anaeroben, gezeigt worden, dass die Dehydrierung die Phosphorylierung bewirkt. Eine andere Phosphorylierung, als die Phosphorylierung durch Dehydrierung gibt es in den grünen Grana nicht. Natürlich entsteht nunmehr die Frage, welche Substanz das Substrat von Dehydrierung und Phosphorylierung ist. Da die Grana keine Dunkelatmung haben und deshalb im Dunkeln nicht phosphorylieren können, auch nicht nach Zusatz von Chinon, so muss das gesuchte Substrat im Licht entstehen; und da der Photolyt der Granareactionen eine Kohlensäureverbindung ist, so muss das gesuchte Substrat eine im Licht entstehende Kohlenstoffverbindung sein. Wegen der Gärungen und dem einzigen bisher bekannten chemischen Mechanismus der Phosphorylierung durch Dehydrierung (4) denkt man an Triosephosphat. Aber chemisch ist jeder Aldehyd möglich. PMID:14004907

Warburg, Otto

1962-01-01

116

The generation of DEM from ALOS/PRISM and ice volume change in Mt. Qomolangma region  

NASA Astrophysics Data System (ADS)

Calculation on glacier volume variations are still greatly limited by the vertical accurate of various data sources till now (Stevens et al., 2004). Therefore, one of the major methodological gaps in the observation of glaciers from space is the measurement of glacier volume changes (Kääb, 2008). Glacier volume changes needs an integrated study and correction on generated DEMs from multi-sources remote sensing data and evaluation of the vertical errors and accuracy. Here, we produced DEMs over mountain glaciers from ASTER and ALOS/PRISM on the northern slope of Mt. Qomolangma (hereafter called the Mt. Qomolangma region), also known as the Mt. Everest, located in the middle Himalayan Mountains, 27° 59-28° 11´N and 86° 44´- 86° 59´E. A series of digital images, include Aster images on 23 Oct 2003, ALOS/AVNIR-2 on 19 Jan 2007, ALOS/AVNIR-2 on 24 Oct 2008, 3 scenes of ALOS/PRISM on 04 Dec 2006, 1:50,000 topographic maps with contour interval of 20 m produced from aerial photographs acquired in 1974 and the 1:50,000 DEM (cell size: 25 m) generated from the topographic maps were used. The DEM was generated based on the three scenes from ALOS/PRISM images and PCI Orthoengine module. The process of DEM generation from ASTER images is very similar to that of ALOS/PRISM. The difference is that: only two images ASTER from nadir and backward views were used here. Table 1 The differences between generated DEMs and the 1:50,000 topographic maps in the non-glacierized area dem5wdemasterprism12_50mprism13_50mprism14_25mprism15_100mSRTM DEMASTER_GDEM Maximum 80.0 920.0 218.0 174.0 258.0 168.0 240.0 437.0 Minimum -123.0 -331.0 -297.0 -367.0 -459.0 -393.0 -315.0 -182.0 aveDEV 23.8 84.0 33.9 36.0 31.3 45.9 67.6 57.9 AVERAGE6.9 75.3 11.3 5.9 1.7 17.2 32.3 45.0 StDEV 30.5 128.0 55.7 59.4 60.6 64.4 85.8 77.2 RMSe 31.2 148.3 56.7 59.6 60.5 66.5 91.5 89.2 Compared various kinds of products of the generated DEMs in the non-glacierized area with the 1:50,000 topographic maps using 215 random points, we found that the mean difference of PRISM DEM to the topographic maps is 1.7 m. However, the mean difference of ASTER GDEM (ASTER_GDEM) is 45m, which is released Version 1 of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Digital Elevation Model (GDEM) on 29 June, 2009. Our result shows that the quality of ALOS/PRISM DEM is better than that of ASTER GDEM, and the calibrated ALOS/PRISM DEM based on the relationship between aspect and DEM difference was more accurate than the original generated one. Fig.1 The generated ASTER DEM on 23 Oct 2003 Fig.2 the generated PRISM DEM on 04 Dec 2006

Ye, Qinghua

2010-05-01

117

YADE-OPEN DEM: an open-source software using a discrete element method to simulate granular material  

Microsoft Academic Search

Purpose – YADE-OPEN DEM is an open-source software based on the discrete element method, (DEM) which uses object oriented programming techniques. The purpose of this paper is to describe the software architecture. Design\\/methodology\\/approach – The DEM chosen uses position, orientation, velocity and angular velocity as independent variables of simulated particles which are subject to explicit leapfrog time-integration scheme (Lagrangian method).

J. Kozicki; F. V. Donzé

2009-01-01

118

Acute environmental toxicity and persistence of DEM, a chemical agent simulant: Diethyl malonate. [Diethyl malonate  

SciTech Connect

The purpose of the following chemical simulant studies is to assess the potential acute environmental effects and persistence of diethyl malonate (DEM). Deposition velocities for DEM to soil surfaces ranged from 0.04 to 0.2 cm/sec. For foliar surfaces, deposition velocities ranged from 0.0002 cm/sec at low air concentrations to 0.05 cm/sec for high dose levels. The residence times or half-lives of DEM deposited to soils was 2 h for the fast component and 5 to 16 h for the residual material. DEM deposited to foliar surfaces also exhibited biphasic depuration. The half-life of the short residence time component ranged from 1 to 3 h, while the longer time component had half-times of 16 to 242 h. Volatilization and other depuration mechanisms reduce surface contaminant levels in both soils and foliage to less than 1% of initial dose within 96 h. DEM is not phytotoxic at foliar mass loading levels of less than 10 {mu}m/cm{sup 2}. However, severe damage is evident at mass loading levels in excess of 17 {mu}g/cm{sup 2}. Tall fescue and sagebrush were more affected than was short-needle pine, however, mass loading levels were markedly different. Regrowth of tall fescue indicated that the effects of DEM are residual, and growth rates are affected only at higher mass loadings through the second harvest. Results from in vitro testing of DEM indicated concentrations below 500 {mu}g/g dry soil generally did not negatively impact soil microbial activity. Short-term effects of DEM were more profound on soil dehydrogenase activity than on soil phosphatase activity. No enzyme inhibition or enhancement was observed after 28 days in incubation. Results of the earthworm bioassay indicate survival to be 86 and 66% at soil doses of 107 and 204 {mu}g DEM/cm{sup 2}, respectively. At higher dose level, activity or mobility was judged to be affected in over 50% of the individuals. 21 refs., 10 figs., 15 tabs.

Cataldo, D.A.; Ligotke, M.W.; Harvey, S.D.; Fellows, R.J.; Li, Shu-mei W.; Van Voris, P.; Wentsel, R.S.

1990-05-01

119

Generation an ideal DEM by fusion shape from shading and interferometry bathymetries for seafloor remote sensing  

NASA Astrophysics Data System (ADS)

In sonar imaging for seafloor remote sensing, research activities are more and more oriented on the use of data fusion approaches. Nowadays, it is well established that using sonar images, the Digital Elevation Maps (DEMs), can be generated by exploiting either the amplitude information or the phase information of the acoustic signal. In this paper, the main interest consists on the generation of a complete Digital Elevation Map (DEM) by the use of a data fusion approach of two existing DEMs issued from two different techniques. The aim of the proposed approach is to elaborate a general interpretation system that coherently links works on data selection and fusion leading to improve DEMs generation and to exploit it in the seafloor remote sensing applications (particularly for the inhomogeneous scenes with a variety terrain). In this paper, shape from shading and the interferometry techniques are considered. Then, the manner of the DEMs fusion proposed, has been based on fuzzy logic and some fuzzy propositions, which defined using experts a priori knowledge source. This promising idea enables information to be managed through the consideration of the imprecision and ambiguity information and the benefit provide by the injection of the a priori knowledge in the decision taken system.

Abu Nokra, Nada M.; Lecornu, Laurent; Zerr, Benoit; Solaiman, Basel; Sintes, Christophe

2004-02-01

120

An effective depression filling algorithm for DEM-based 2-dimensional surface flow modelling  

NASA Astrophysics Data System (ADS)

The surface runoff process in fluvial/pluvial flood modelling is often simulated employing a two-dimensional (2-D) diffusive wave approximation to described by grid based digital elevation models (DEMs). However, a serious problem of this approach may arise when using a 2-D surface flow model which exchanges flows through adjacent cells, or conventional rink removal algorithms which also allow flow to be exchanged along diagonal directions, due to the existence of artificial depression in DEMs. This study firstly analyses the two types of depressions in DEMs and reviews the current depression filling algorithms with a medium sized basin in South-East England, the Upper Medway Catchment (220 km2) used to demonstrate the depression issue in 2-D surface runoff simulation by MIKE SHE with different DEM resolutions (50 m, 100 m and 200 m). An alternative depression-filling algorithm for 2-D overland flow modelling is developed and evaluated by comparing the simulated flows at the outlet of the catchment. This result suggests that the depression estimates at different grid resolution of DEM highly influences overland flow estimation and the new depression filling algorithm is shown to be effective in tackling this issue when comparing simulations in sink-dominated and sink-free digital elevation models, especially for depressions in relatively flat areas on digital land surface models.

Zhu, D.; Ren, Q.; Xuan, Y.; Chen, Y.; Cluckie, I.

2012-09-01

121

Integration of 2-D hydraulic model and high-resolution LiDAR-derived DEM for floodplain flow modeling  

NASA Astrophysics Data System (ADS)

The rapid progress of Light Detection And Ranging (LiDAR) technology has made acquirement and application of high-resolution digital elevation model (DEM) data increasingly popular, especially with regards to the study of floodplain flow modeling. High-resolution DEM data include many redundant interpolation points, needs a high amount of calculation, and does not match the size of computational mesh. These disadvantages are a common problem for floodplain flow modeling studies. Two-dimensional (2-D) hydraulic modeling, a popular method of analyzing floodplain flow, offers high precision of elevation parameterization for computational mesh while ignoring much micro-topographic information of the DEM data itself. We offer a flood simulation method that integrates 2-D hydraulic model results and high-resolution DEM data, enabling the calculation of flood water levels in DEM grid cells through local inverse distance weighted interpolation. To get rid of the false inundation areas during interpolation, it employs the run-length encoding method to mark the inundated DEM grid cells and determine the real inundation areas through the run-length boundary tracing technique, which solves the complicated problem of the connectivity between DEM grid cells. We constructed a 2-D hydraulic model for the Gongshuangcha polder, a flood storage area of Dongting Lake, using our integrated method to simulate the floodplain flow. The results demonstrate that this method can solve DEM associated problems efficiently and simulate flooding processes with greater accuracy than DEM only simulations.

Shen, D.; Wang, J.; Cheng, X.; Rui, Y.; Ye, S.

2015-02-01

122

Kindliche Leukämien und EMF-Expositionen in der Umgebung hochfrequenter Sendestationen (KiSS) - Fragestellung und Studienbeschreibung  

NASA Astrophysics Data System (ADS)

Im Rahmen einer Fall-Kontroll-Studie wird untersucht, ob es einen Zusammenhang zwischen dem Leukämierisiko bei Kindern und der Exposition gegenüber elektromagnetischen Feldern in der Umgebung leistungsstarker Sendestationen von Rundfunk und Fernsehen gibt. Bislang wurden fünf Studien im Umkreis von Rundfunksendeanlagen durchgeführt. Deren Aussagekraft ist jedoch durch eine grobe Expositionsabschätzung und ihren ökologischen Studienansatz ohne individuelle Expositionsbestimmung limitiert. Wesentliches Element der hier vorgestellten Studie ist dagegen eine individuelle Expositionsabschätzung, die zum einen auf der Geocodierung von Wohnadressen und Expositionspunktquellen und zum andern auf den tatsächlichen Strahlungsleistungen und Betriebsdaten der Senderbetreiber beruht. Das Studiengebiet besteht aus den Umgebungen von 17 leistungsstarken AM-Mittelwellensendern und 8 UKW-FM- bzw. analogen TV-Sendern in Westdeutschland. Zur Studienpopulation gehören alle im Diagnosezeitraum von 1984 bis 2003 aufgetretenen Fälle, die im Studiengebiet leben bzw. gelebt haben. Als Fälle werden alle Kinder definiert, die zum Zeitpunkt der Diagnose zwischen 0-14 Jahren alt waren, bei denen eine primäre Leukämie diagnostiziert wurde und die dem Deutschen Kinderkrebsregister bekannt sind. Jedem Fallkind werden 3 gleich alte Kontrollkinder gleichen Geschlechts aus der gleichen Senderumgebung gegenübergestellt. Möglich wurde diese Untersuchung durch die Förderung durch Mittel des Deutschen Mobilfunkforschungsprogramms sowie durch die Mitarbeit aller relevanten Senderbetreiber und des Deutschen Kinderkrebsregisters an der Universität Mainz. Sie soll bis August 2007 abgeschlossen sein.

Brüggemeyer, H.; Philipp, J.; Merzenich, H.; Schmiedel, S.; Blettner, M.; Schüz, J.

2007-06-01

123

FEM × DEM modelling of cohesive granular materials: Numerical homogenisation and multi-scale simulations  

NASA Astrophysics Data System (ADS)

The article presents a multi-scale modelling approach of cohesive granular materials, its numerical implementation and its results. At microscopic level, Discrete Element Method (DEM) is used to model dense grains packing. At the macroscopic level, the numerical solution is obtained by a Finite Element Method (FEM). In order to bridge the micro- and macro-scales, the concept of Representative Elementary Volume (REV) is applied, in which the average REV stress and the consistent tangent operators are obtained in each macroscopic integration point as the results of DEM's simulation. In this way, the numerical constitutive law is determined through the detailed modelling of the microstructure, taking into account the nature of granular materials. We first elaborate the principle of the computation homogenisation (FEM × DEM), then demonstrate the features of our multiscale computation in terms of a biaxial compression test. Macroscopic strain location is observed and discussed.

Nguyen, Trung Kien; Combe, Gaël; Caillerie, Denis; Desrues, Jacques

2014-10-01

124

Discrete Element Method (DEM) Application to The Cone Penetration Test Using COUPi Model  

NASA Astrophysics Data System (ADS)

The cone penetration test (CPT) is a soil strength measurement method to determine the tip resistance and sleeve friction versus depth while pushing a cone into regolith with controlled slow quasi-static speed. This test can also be used as an excellent tool to validate the discrete element method (DEM) model by comparing tip resistance and sleeve friction from experiments to model results. DEM by nature requires significant computational resources even for a limited number of particles. Thus, it is important to find particle and ensemble parameters that produce valuable results within reasonable computation times. The Controllable Objects Unbounded Particles Interaction (COUPi) model is a general physical DEM code being developed to model machine/regolith interactions as part of a NASA Lunar Science Institute sponsored project on excavation and mobility modeling. In this work, we consider how different particle shape and size distributions defined in the DEM influence the cone tip and friction sleeve resistance in a CPT DEM simulation. The results are compared to experiments with cone penetration in JSC-1A lunar regolith simulant. The particle shapes include spherical particles, particles composed from the union of three spheres, and some simple polyhedra. This focus is driven by the soil mechanics rule of thumb that particle size and shape distributions are the two most significant factors affecting soil strength. In addition to the particle properties, the packing configuration of an ensemble strongly affects soil strength. Bulk density of the regolith is an important characteristic that significantly influences the tip resistance and sleeve friction (Figure 1). We discuss different approaches used to control granular density in the DEM, including how to obtain higher bulk densities, using numerical "shaking" techniques and varying the friction coefficient during computations.

Kulchitsky, A. V.; Johnson, J.; Wilkinson, A.; DeGennaro, A. J.; Duvoy, P.

2011-12-01

125

Quality assessment of Digital Elevation Model (DEM) in view of the Altiplano hydrological modeling  

NASA Astrophysics Data System (ADS)

Topography is crucial data input for hydrological modeling but in many regions of the world, the only way to characterize topography is the use of satellite-based Digital Elevation Models (DEM). In some regions, the quality of these DEMs remains poor and induces modeling errors that may or not be compensated by model parameters tuning. In such regions, the evaluation of these data uncertainties is an important step in the modeling procedure. In this study, which focuses on the Altiplano region, we present the evaluation of the two freely available DEM. The shuttle radar topographic mission (SRTM), a product of the National Aeronautics and Space Administration (NASA) and the Advanced Space Born Thermal Emission and Reflection Global Digital Elevation Map (ASTER GDEM), data provided by the Ministry of Economy, Trade and Industry of Japan (MESI) in collaboration with the NASA, are widely used. While the first represents a resolution of 3 arc seconds (90m) the latter is 1 arc second (30m). In order to select the most reliable DEM, we compared the DEM elevation with high qualities control points elevation. Because of its large spatial coverture (track spaced of 30 km with a measure of each 172 m) and its high vertical accuracy which is less than 15 cm in good weather conditions, the Geoscience Laser Altimeter System (GLAS) on board on the Ice, Cloud and Land elevation Satellite of NASA (ICESat) represent the better solution to establish a high quality elevation database. After a quality check, more than 150 000 ICESat/GLAS measurements are suitable in terms of accuracy for the Altiplano watershed. This data base has been used to evaluate the vertical accuracy for each DEM. Regarding to the full spatial coverture; the comparison has been done for both, all kind of land coverture, range altitude and mean slope.

Satgé, F.; Arsen, A.; Bonnet, M.; Timouk, F.; Calmant, S.; Pilco, R.; Molina, J.; Lavado, W.; Crétaux, J.; HASM

2013-05-01

126

How large is the Upper Indus Basin? The pitfalls of auto-delineation using DEMs  

NASA Astrophysics Data System (ADS)

Extraction of watershed areas from Digital Elevation Models (DEMs) is increasingly required in a variety of environmental analyses. It is facilitated by the availability of DEMs based on remotely sensed data, and by Geographical Information System (GIS) software. However, accurate delineation depends on the quality of the DEM and the methodology adopted. This paper considers automated and supervised delineation in a case study of the Upper Indus Basin (UIB), Pakistan, for which published estimates of the basin area show significant disagreement, ranging from 166,000 to 266,000 km2. Automated delineation used ArcGIS Archydro and hydrology tools applied to three good quality DEMs (two from SRTM data with 90m resolution, and one from 30m resolution ASTER data). Automatic delineation defined a basin area of c.440,000 km2 for the UIB, but included a large area of internal drainage in the western Tibetan Plateau. It is shown that discrepancies between different estimates reflect differences in the initial extent of the DEM used for watershed delineation, and the unchecked effect of iterative pit-filling of the DEM (going beyond the filling of erroneous pixels to filling entire closed basins). For the UIB we have identified critical points where spurious addition of catchment area has arisen, and use Google Earth to examine the geomorphology adjacent to these points, and also examine the basin boundary data provided by the HydroSHEDS database. We show that the Pangong Tso watershed and some other areas in the western Tibetan plateau are not part of the UIB, but are areas of internal drainage. Our best estimate of the area of the Upper Indus Basin (at Besham Qila) is 164,867 km2 based on the SRTM DEM, and 164,853 km2 using the ASTER DEM). This matches the catchment area measured by WAPDA SWHP. An important lesson from this investigation is that one should not rely on automated delineation, as iterative pit-filling can produce spurious drainage networks and basins, when there are areas of internal drainage nearby.

Khan, Asif; Richards, Keith S.; Parker, Geoffrey T.; McRobie, Allan; Mukhopadhyay, Biswajit

2014-02-01

127

Influence of Lossy Compressed DEM on Radiometric Correction for Land Cover Classification of Remote Sensing Images  

NASA Astrophysics Data System (ADS)

World coverage Digital Elevation Models (DEM) have progressively increased their spatial resolution (e.g., ETOPO, SRTM, or Aster GDEM) and, consequently, their storage requirements. On the other hand, lossy data compression facilitates accessing, sharing and transmitting large spatial datasets in environments with limited storage. However, since lossy compression modifies the original information, rigorous studies are needed to understand its effects and consequences. The present work analyzes the influence of DEM quality -modified by lossy compression-, on the radiometric correction of remote sensing imagery, and the eventual propagation of the uncertainty in the resulting land cover classification. Radiometric correction is usually composed of two parts: atmospheric correction and topographical correction. For topographical correction, DEM provides the altimetry information that allows modeling the incidence radiation on terrain surface (cast shadows, self shadows, etc). To quantify the effects of the DEM lossy compression on the radiometric correction, we use radiometrically corrected images for classification purposes, and compare the accuracy of two standard coding techniques for a wide range of compression ratios. The DEM has been obtained by resampling the DEM v.2 of Catalonia (ICC), originally having 15 m resolution, to the Landsat TM resolution. The Aster DEM has been used to fill the gaps beyond the administrative limits of Catalonia. The DEM has been lossy compressed with two coding standards at compression ratios 5:1, 10:1, 20:1, 100:1 and 200:1. The employed coding standards have been JPEG2000 and CCSDS-IDC; the former is an international ISO/ITU-T standard for almost any type of images, while the latter is a recommendation of the CCSDS consortium for mono-component remote sensing images. Both techniques are wavelet-based followed by an entropy-coding stage. Also, for large compression ratios, both techniques need a post processing for correctly delimiting coastline, avoiding the confusion between elevation and no-data values. Six (from March 2005 to May 2007) geometrically corrected Landsat-5 images on the path-row 197-031 have been used. The six optical bands and the NDVI for each date have been introduced in a powerful hybrid classification process. The training areas and the ground truth have been obtained from the Mapa de Cobertes del Sòl de Catalunya (v. 3), a land cover map created by photointerpretation of 0.5 m orthophotomaps acquired between 2005 and 2007 and covering all the extension of Catalonia. The legend has been reduced from 233 categories to 21. Preliminary results have shown that the effect on land cover classification of applying lossy compression to the DEM used in the radiometric correction is small (lower than 1%) even for compression ratios up to 200:1. Comparing classification performance after a compression of 5:1 and and a compression of 200:1 with both coding standards showed that: a) the percentage of correctly classified image was 73%; b) 20% was wrongly classified; c) 3.5% was wrongly classified at compression ratio 5:1; and d) also 3.5% was wrongly classified at compression ratio 200:1. These results are the first in the literature to analyze the effect of DEM lossy compressing when DEM are employed for radiometric correction.

Moré, G.; Pesquer, L.; Blanes, I.; Serra-Sagristà, J.; Pons, X.

2012-12-01

128

Time series analysis of SAR interferometry derived DEM of Kuwait desert to reduce the affects of atmosphere  

NASA Astrophysics Data System (ADS)

Twenty five ASAR scenes are analyzed to find the suitable pairs for generating DEM of Kuwait desert area. About 40 pairs are suitable for generating DEMs. A unique combination of seven DEM are possible with a single master image whose perpendicular baseline component varies between 233 to 393m. GAMMA inerferometric package coupled with ERDAS image processing package are used in the analysis. The seven DEMs are compared with the 90 m DEM derived from SRTM. It has been found that the RMS error varies from 1.9 m to 15.3 m. The highest RMS error refers to day-difference of 525 days with average coherence value of 0.71 (lowest of all). Therefore, correlation will be the cause of higher errors. However, 35 days day-difference pair gave RMS error of 5.5 m with highest coherence value (0.93) which is supposed to produce the lowest RMS error. For the study of spatial distribution of errors, Interferometric DEMs are subtracted from DEM of SRTM. From this analysis, it is observed that the atmospheric affects are aligned and varies systematically. It can give an error in elevation as high as 15 m. Therefore, one should be very careful in using SAR interfoermetry technology for DEM generation even for desert regions.

Rao, K. S.; Al Jassar, H. K.

2008-10-01

129

DEM simulation of industrial particle flows: case studies of dragline excavators, mixing in tumblers and centrifugal mills  

Microsoft Academic Search

Discrete element methods (DEM) are now sufficiently well developed to plausibly model industrial and mining related particle flows. Three cases studies of such DEM simulations are presented here; dragline excavators, mixing in tumblers and charge motion in centrifugal mills. They show the breadth of application now possible and the types of predictions that can be made for each. More importantly,

Paul W. Cleary

2000-01-01

130

Bernd Borchert, Klaus Reinhardt (Univ. Tbingen) 30.8.2008 Trojaner-sicheres Online Banking mit dem Foto-Handy  

E-print Network

Bernd Borchert, Klaus Reinhardt (Univ. Tübingen) 30.8.2008 Trojaner-sicheres Online Banking mit dem Foto-Handy Online Banking mit dem TAN- oder iTAN - Verfahren ist unsicher: ein Trojaner-Virus, der sich Foto-PIN Programm in einem unabhörbaren Initialisierungs-Vorgang online auf der www-Seite der Bank

Borchert, Bernd

131

Representative hillslope methods for applying the WEPP model with DEMs and GIS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Modeling procedures called the Hillslope methods were developed that use geographical information systems (GIS) and digital elevation models (DEMs) to assess water erosion in small watersheds with the Water Erosion Prediction Project (WEPP) model. The Hillslope methods are automated procedures to d...

132

Ostdeutschland 20 Jahre nach dem Mauerfall: was war und was ist heute mit der Wirtschaft?  

Microsoft Academic Search

Der Artikel zeigt in den grundlegenden Zügen die Entwicklung in Ostdeutschland seit dem Beginn der Umstrukturierung und zieht eine Bilanz zum Stand des Anpassungsprozesses nach 20 Jahren des Mauerfalls. Wie sich an der Entwicklung der Wirtschaftsleistung zeigen lässt, ist der wirtschaftliche Neuaufbau gut voran gekommen. Allerdings ist das Resultat hinter den Erwartungen zur Wendezeit zurückgeblieben. Und weiterhin sind die neuen

Karl Brenke; Klaus F. Zimmermann

2009-01-01

133

SCALE INVARIANT TOPMODEL FOR THE SOLUTION OF DEM RESOLUTION EFFECTS AND PARAMETER INCONSISTENCY IN HYDROLOGICAL MODELING  

Microsoft Academic Search

The topographic index of TOPMODEL is scale dependent which leads identified parameter values to be dependent on a DEM resolution. This makes difficult to use model parameter values identified with a different resolution TOPMODEL. To overcome this problem, this research has developed a concept of resolution factor to account for the scale effect in up-slope contributing area per unit contour

Nawa Raj PRADHAN; Yasuto TACHIKAWA; Kaoru TAKARA

2004-01-01

134

Downtown Toronto building outlines with heights, clutter data, DEM, contours and places  

E-print Network

Title: Downtown Toronto building outlines with heights, clutter data, DEM, contours and places Data Date(s): August 2009 Updates: N/A Abstract: - 3D Building Outlines in the City of Toronto core): Toronto, Ontario Keywords (Subject): Land use, digital elevation model, building heights, contours

135

Spuren von Massenbewegungen auf dem Grund des Vierwaldstttersees bei Weggis: Die Ereignisse von 1601 und 1795  

E-print Network

83 Spuren von Massenbewegungen auf dem Grund des Vierwaldstättersees bei Weggis: Die Ereignisse von- gangenheit wiederholt von subaquatischen Massenbewegungen erfasst (z. B. Schnell- mann et al. 2006). Die zwei jüngsten Gross- ereignisse sind die von einem Erdbeben in Unterwalden (MW ~ 6.2) ausgelöste subaqua- tische

Gilli, Adrian

136

Tau auf dem Bei Alzheimer-Forschung denkt man nicht unbedingt an Teilchenbeschleuniger. Das Deutsche  

E-print Network

Tau auf dem Gedächtnis Bei Alzheimer-Forschung denkt man nicht unbedingt an Teilchenbeschleuniger an Nervenzellen In einer gesunden Nervenzelle stabilisiert das tau-Protein (rot) das Zellskelett im Axon der Zelle (1). In einer Zelle mit einem zusätzlichen tau-Gen, das schnell verklumpendes tau-Protein bildet

Spang, Rainer

137

Spirit Workshop 2010 -Toulouse Status of the TanDEM-X Mission  

E-print Network

, understanding and development of new algorithms for multistatic SAR, polarimetric SAR interferometry, super Polarimetric SAR InterferometryPolarimetricPolarimetric SAR InterferometrySAR Interferometry ......... Ground? Content #12;Slide 3 Launch 21 of June 2010 TanDEM-X TerraSAR-X add-on for Digital Elevation Measurments

Berthier, Etienne

138

Landform analysis of slope movements using DEM in Higashikubiki area, Japan  

Microsoft Academic Search

Various numerical analyses using 25m-grid DEMs were compared with rasterized slope movement distribution maps and geological maps of the Higashikubiki area in Niigata Prefecture, Japan. Slope movement distribution maps included five classes: “stable slope”, “landslide mass”, “landslide scarp”, “collapse scarp” and “crack”. Their statistical characteristics were clarified by numerical landform analyses for each lithology. Frequency distributions of slope angle were

Junko Iwahashi; Shiaki Watanabe; Takahiko Furuya

2001-01-01

139

Verification of X-band SRTM DEM data quality in New Zealand  

Microsoft Academic Search

The quality of 20 Shuttle Radar Topography Mis- sion DEM tiles of New Zealand supplied by DLR has been characterised in terms of the altimetric and planimetric product accuracy specifications. Using precise survey-grade elevation points and a land cover classification, we show that there is strong dependence of the X-SAR SRTM error on the land cover class, but no significant

S. J. McNeill; S. E. Belliss; H. C. North; D. Pairman; J. Barringer

2005-01-01

140

Simulation of dilute pneumatic conveying with different types of bends by CFD-DEM  

NASA Astrophysics Data System (ADS)

Bends are one of the most commonly used facilities to change flow direction in pneumatic conveying. It is important to understand the effect of the bend to the gas-solid flow structures in a pneumatic conveying system. CFD-DEM is one of powerful methods to study the fundamentals of gas-solid flow, as it takes the particle-particle and particle-wall collisions into account. But the time consumption is one of major limitations for its application. In this paper, a three-dimensional CFD-DEM model which ignores the effect of void fraction to the gas phase is used to simulate the dilute gas-solid flow. Gas-solid flows in different types of bends including horizontal-vertical, vertical-horizontal and horizontal-horizontal 90° bends are studied. The present CFD-DEM model is verified by compared the rope structure with the result for traditional CFD-DEM model in horizontal-vertical case. Compared the particle rope dispersion in different types of bends, the rope disperses more quickly in the vertical-horizontal case than others, and the solid flow structure is the most complicated in the horizontal- horizontal case. As their various solid flow structures, the collision data of three cases also seem different.

Du, J.; Hu, G. M.; Fang, Z. Q.; Wang, J.

2014-12-01

141

Two types of the regular stratovolcano shape: a DEM-based morphometrical analysis  

Microsoft Academic Search

We studied the shape of the most regular-shaped stratovolcanoes of the world to mathematically define the form of the ideal stratovolcano. Based on the Shuttle Radar Topographic Mission (SRTM) DEM data, we selected the 20 most circular and symmetrical volcanoes, which incidentally all belong to subduction-related arcs surrounding the Pacific. The selection of volcanoes benefits from the introduction of a

Dávid Karátson; Massimiliano Favalli; Simone Tarquini; Alessandro Fornaciai; Gerhard Wörner

2010-01-01

142

Diffusion-Based Coarse Graining in Hybrid Continuum--Discrete Solvers: Applications in CFD--DEM  

E-print Network

In this work, a coarse graining method previously proposed by the authors based on solving diffusion equations is applied to CFD--DEM simulations, where coarse graining is used to obtain solid volume fraction, particle phase velocity, and fluid--particle interaction forces. By examining the conservation requirements, the variables to solve diffusion equations for in CFD--DEM simulations are identified. The algorithm is then implemented to a CFD--DEM solver based on OpenFOAM and LAMMPS, the former being a general-purpose, three-dimensional CFD solver based on unstructured meshes. Numerical simulations are performed for a fluidized bed by using the CFD--DEM solver with the diffusion-based coarse graining algorithm. Converged results are obtained on successively refined meshes, even for meshes with cell sizes comparable to or smaller than the particle diameter. This is a critical advantage of the proposed method over many existing coarse graining methods, and would be particularly valuable when small cells are r...

Sun, Rui

2014-01-01

143

04.03.2010Prof. Dr. H. Ingensand Geodtische Messtechnik und Ingenieurgeodsie Innenraumpositionierung mit dem  

E-print Network

Latency Introduction in Wireless Positioning #12;· Global System for Mobile Communication (GSM) can Innenraumpositionierung mit dem Cricket-System (Indoor Positioning using Crickets) Rainer Mautz Freitag, 05. März 2010, 8 des Cricket Systems -50 0 50 100 -50 0 50 -50 0 50 Z 01 Clustersize: 5 nodes 07 06 04 08

144

Synergy of Image and Digital Elevation Models (DEMS) Information for Virtual Reality  

NASA Astrophysics Data System (ADS)

In the framework of 3D visualization and real-time rendering of large remote sensing image databases, several signal processing techniques are presented and evaluated to filter/enhance SAR Digital Elevation Models (DEMs). Through the SRTM DEM, the interest of InSAR data for such applications is illustrated. A non stationary bayesian filter is presented to remove noise and small artefacts which pervade the SAR DEM while preserving structures and information content. Results obtained are very good, nevertheless large artefacts cannot be filtered and some artefacts remain. Therefore, image information have to be inserted to produce more realistic views. This second step is done by using a segmentation algorithm on the image data. By a topology analysis, the extracted objects are classified/stored in a tree structure to describe the topologic relations between the objects and reflect their interdependencies. An interactive learning procedure is done through a Graphical User Interface to link the signal classes to the semantic ones, i.e. to include human knowledge in the system. The selected information in form of objets are merged/fused in the DEM by assigning regularisation constraints.

Maire, C.; Datcu, M.

2004-09-01

145

SLOPE STABILITY ANALYSIS OF THE ILIAMNA VOLCANO, ALASKA, USING ASTER TIR, SRTM DEM, AND AEROMAGNETIC DATA  

E-print Network

SLOPE STABILITY ANALYSIS OF THE ILIAMNA VOLCANO, ALASKA, USING ASTER TIR, SRTM DEM and digital elevation models to create a hazard index that characterizes slope stability on active volcanoes. Introduction Volcano monitoring in the Aleutians is of great importance due to the heavy amount of airplane

146

Behandlung der kongenitalen Skoliose mit dem Vertical-expandable-prosthetic-titanium-rib-Implantat  

Microsoft Academic Search

Zusammenfassung Kinder mit kongenitaler thorakaler Skoliose, assoziiert mit Rippenfusionen, einseitigen unsegmentierten Spangen und kontralateraler Halbwirbelbildung, haben ohne Therapie eine massive Kurvenprogression. Aufgrund der Annahme, dass die unsegmentierten Spangen nicht wachsen, wurde in der Vergangenheit früh operativ fusioniert, was eine verkürzte Wirbelsäulenlänge und ein vermindertes Lungenwachstum zur Folge hatte. Durch ein neues Operationsverfahren mit einem an den Rippen verankerten Längsimplantat, dem

A. K. Hell; F. Hefti; R. M. Campbell

2004-01-01

147

In greren Lettern als der Titel prangt einer der beiden Autoren auf dem Cover  

E-print Network

In grö�eren Lettern als der Titel prangt einer der beiden Autoren auf dem Cover: Stephen Hawking letzten Schluss vorstellen, ,,42" oder der gro�e Flop Stephen Hawking, Leonard Mlodinow, Der gro�e Entwurf jenen, die es als Bestsellerauto- ren ganz oben in die Sachbuchcharts ge- schafft haben. Hawkings im

148

90-METER DIGITAL ELEVATION MODEL (DEM) FOR THE MID-ATLANTIC INTEGRATED ASSESSMENT (MAIA) STUDY AREA  

EPA Science Inventory

This data set is a geographic information system (GIS) coverage of the 90-meter digital elevation model (DEM) for the United States Environmental Protection Agency (USEPA) Mid-Atlantic Integrated Assessment (MAIA) Project region. The coverage was produced using US Geological Su...

149

Mit dem Namen Charles Darwin verbinden sich immer auch die nach ihm benannten  

E-print Network

Mit dem Namen Charles Darwin verbinden sich immer auch die nach ihm benannten Darwinfinken auf den entwickelten weitgehend übereinstimmt. Seitdem Charles Darwin seine �berle- gungen nach langen Jahren des wissenschaftshistori- schen Bedeutung von Charles Darwin. Er beschreibt, wie Darwin ein neues Verständ- nis von der

150

Sensitivity Analysis of Uav-Photogrammetry for Creating Digital Elevation Models (dem)  

NASA Astrophysics Data System (ADS)

This study evaluates the potential that lies in the photogrammetric processing of aerial images captured by unmanned aerial vehicles. UAV-Systems have gained increasing attraction during the last years. Miniaturization of electronic components often results in a reduction of quality. Especially the accuracy of the GPS/IMU navigation unit and the camera are of the utmost importance for photogrammetric evaluation of aerial images. To determine the accuracy of digital elevation models (DEMs), an experimental setup was chosen similar to the situation of data acquisition during a field campaign. A quarry was chosen to perform the experiment, because of the presence of different geomorphologic units, such as vertical walls, piles of debris, vegetation and even areas. In the experimental test field, 1042 ground control points (GCPs) were placed, used as input data for the photogrammetric processing and as high accuracy reference data for evaluating the DEMs. Further, an airborne LiDAR dataset covering the whole quarry and additional 2000 reference points, measured by total station, were used as ground truth data. The aerial images were taken using a MAVinci Sirius I - UAV equipped with a Canon 300D as imaging system. The influence of the number of GCPs on the accuracy of the indirect sensor orientation and the absolute deviation's dependency on different parameters of the modelled DEMs was subject of the investigation. Nevertheless, the only significant factor concerning the DEMs accuracy that could be isolated was the flying height of the UAV.

Rock, G.; Ries, J. B.; Udelhoven, T.

2011-09-01

151

A DEM simulation system for equipment of powder processing and bulk materials transportation  

Microsoft Academic Search

Discrete Element Method (DEM) is applied to study the dynamics behavior of equipment of powder processing and bulk materials transportation. It is assumed that powder or bulk materials are divided into discrete elements. The kinetic equations for each element are conducted by means of the Newton's second law and the motion of all the elements is achieved by employing the

Guoming Hu; Muqun Liu; Yu Liu; Hui Wan; Liping Liu

2010-01-01

152

Optical-radar-DEM remote sensing data integration for geological mapping in the Afar Depression, Ethiopia  

Microsoft Academic Search

The advantages of integrating optical (Landsat Enhanced Thematic Mapper Plus (ETM+) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)) and radar (Shuttle Imaging Radar (SIR) C, X-band Synthetic Aperture Radar (SAR) and RADARSAT-1) remote sensing data, and digital elevation models (DEMs) (Shuttle Radar Topography Mission (SRTM)) for geological mapping in arid regions such as the Afar Depression in Ethiopia

Allison K. Thurmond; Mohamed G. Abdelsalam; John B. Thurmond

2006-01-01

153

Validation of DEMs Derived from High Resolution SAR Data: a Case Study on Barcelona  

NASA Astrophysics Data System (ADS)

In recent years, Synthetic Aperture Radar (SAR) data have been widely used for scientific applications and several SAR missions were realized. The active sensor principle and the signal wavelength in the order of centimeters provide all-day and all-weather capabilities, respectively. The modern German TerraSAR-X (TSX) satellite provides high spatial resolution down to one meter. Based on such data SAR Interferometry may yield high quality digital surface models (DSMs), which includes points located on 3d objects such as vegetation, forest, and elevated man-made structures. By removing these points, digital elevation model (DEM) representing the bare ground of Earth is obtained. The primary objective of this paper is the validation of DEMs obtained from TSX SAR data covering Barcelona area, Spain, in the framework of a scientific project conducted by ISPRS Working Group VII/2 "SAR Interferometry" that aims the evaluation of DEM derived from data of modern SAR satellite sensors. Towards this purpose, a DSM was generated with 10 m grid spacing using TSX StripMap mode SAR data and converted to a DEM by filtering. The accuracy results have been presented referring the comparison with a more accurate (10 cm-1 m) digital terrain model (DTM) derived from large scale photogrammetry. The results showed that the TSX DEM is quite coherent with the topography and the accuracy is in between ±8-10 m. As another application, the persistent scatterer interferometry (PSI) was conducted using TSX data and the outcomes were compared with a 3d city model available in Google Earth, which is known to be very precise because it is based on LIDAR data. The results showed that PSI outcomes are quite coherent with reference data and the RMSZ of differences is around 2.5 m.

Sefercik, U. G.; Schunert, A.; Soergel, U.; Watanabe, K.

2012-07-01

154

Fusion of high-resolution DEMs derived from COSMO-SkyMed and TerraSAR-X InSAR datasets  

NASA Astrophysics Data System (ADS)

Voids caused by shadow, layover, and decorrelation usually occur in digital elevation models (DEMs) of mountainous areas that are derived from interferometric synthetic aperture radar (InSAR) datasets. The presence of voids degrades the quality and usability of the DEMs. Thus, void removal is considered as an integral part of the DEM production using InSAR data. The fusion of multiple DEMs has been widely recognized as a promising way for the void removal. Because the vertical accuracy of multiple DEMs can be different, the selection of optimum weights becomes a key problem in the fusion and is studied in this article. As a showcase, two high-resolution InSAR DEMs near Mt. Qilian in northwest China are created and then merged. The two pairs of InSAR data were acquired by TerraSAR-X from an ascending orbit and COSMO-SkyMed from a descending orbit. A maximum likelihood fusion scheme with the weights optimally determined by the height of ambiguity and the variance of phase noise is adopted to syncretize the two DEMs in our study. The fused DEM has a fine spatial resolution of 10 m and depicts the landform of the study area well. The percentage of void cells in the fused DEM is only 0.13 %, while 6.9 and 5.7 % of the cells in the COSMO-SkyMed DEM and the TerraSAR-X DEM are originally voids. Using the ICESat/GLAS elevation data and the Chinese national DEM of scale 1:50,000 as references, we evaluate vertical accuracy levels of the fused DEM as well as the original InSAR DEMs. The results show that substantial improvements could be achieved by DEM fusion after atmospheric phase screen removal. The quality of fused DEM can even meet the high-resolution terrain information (HRTI) standard.

Jiang, Houjun; Zhang, Lu; Wang, Yong; Liao, Mingsheng

2014-06-01

155

1682 IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 43, NO. 7, JULY 2005 On Merging High-and Low-Resolution DEMs From  

E-print Network

data in airborne Topographic Synthetic Aperture Radar (TOPSAR) DEMs using a low-resolution Shuttle-validation methods to obtain the optimal weighting for the PE filter and SRTM DEM constraints. Index Terms--Interpolation, digital elevation model (DEM), Topographic Synthetic Aperture Radar (TOPSAR), Shuttle Radar Topography

Segall, Paul

156

Detailed geomorphological mapping from high resolution DEM data (LiDAR, TanDEM-X): two case studies from Germany and SE Tibet  

NASA Astrophysics Data System (ADS)

Two major obstacles are hampering the production of high resolution geomorphological maps: the complexity of the subject that should be depicted and the enormous efforts necessary to obtain data by field work. The first factor prevented the establishment of a generally accepted map legend; the second hampered efforts to collect comprehensive sets of geomorphological data. This left geomorphologists to produce applied maps, focusing on very few layers of information and often not sticking to any of the numerous standards proposed in the second half of the 20th century. Technological progress of the recent years, especially in the fields of digital elevation models, GIS environments, and computational hardware, today offers promising opportunities to overcome the obstacles and to produce detailed geomorphological maps even for remote or inhospitable regions. The feasibility of detailed geomorphological mapping from two new sets of digital elevation data, the 1 m LiDAR DTM provided by Germany's State Surveying Authority and the upcoming TanDEM-X DEM, has been evaluated in two case studies from a low mountain range in Germany and a high mountain range in SE Tibet. The results indicate that most layers of information of classical geomorphological maps (e.g. the German GMK) can be extracted from this data at appropriate scales but that significant differences occur concerning the quality and the grades of certainty of key contents. Generally, an enhancement of the geomorphographical, especially the geomorphometrical, and a weakening of geomorphogenetical contents was observed. From these findings, theoretical, methodological, and cartographical remarks on detailed geomorphological mapping from DEM data in GIS environments were educed. As GIS environments decouple data and design and enable the geomorphologist to choose information layer combinations freely to fit research topics, a general purpose legend becomes obsolete. Yet, a unified data structure is demanded to ensure that data collected by different scientists or in different studies can be exchanged and reused.

Loibl, D.

2012-04-01

157

Testing DEM-based atmospheric corrections to SAR interferograms over the Los Angeles basin  

NASA Astrophysics Data System (ADS)

Atmospheric water vapor delay is the major source of noise in SAR interferograms. It is considered a prime disadvantage of high-precision InSAR technology. Without the atmospheric delay being corrected, it is hard to see any slow surface movements of the ground, e.g. fault creep; and it is impossible to validate Permanent Scatters InSAR method either, which assumes that water vapor can be estimated and removed by considering time series of interferograms. As long as the water vapor delay is estimated or measured, not only can we solve the previous two problems, but also reduce the errors in geodetic measurements, and improve the accuracy in generating Digital Elevation Models (DEMs) with ERS-1/2 tandem data. In order to reduce water vapor delay, there are some possible solutions using different data sets, including GPS, MODIS, and MERIS etc. This project is a method based on DEMs. It intends to find the relationship between topography and atmospheric water vapor delay in SAR interferograms so the water vapor signals can be reduced in interferograms. It is assumed that the atmospheric water vapor delay is linearly related to the topography over a certain distance. For example, the low phase delay appears over the places where the elevation is high; or low elevation leads to high phase delay. We tested 17 interferograms over the LA basin -- 5 from the ERS-1/2 tandem mission between 1995 and 1996; 12 from EnviSAT between 2005 and 2007 with the time spans from 35 days to 8 months. The basic idea was to divide each interferogram and DEM into a series of small windows. Then the coefficients of the relationship between the phase and the corresponding elevation in each same window were found. After interpolating these coefficients across the interferogram area, we obtained the water vapor correction by multiplying the coefficients by elevations. In this project, we tested three interpolation methods -- linear, spline, and cubic, but we found that there was little difference among these three methods. In order to test the result, we calculated the root mean square (RMS) phase of the data before and after correcting, and assessed the similarity of the correction between neighboring windows (i.e. the ‘coherence’ of the correction). We varied the sizes of windows to find the size which was most effective in removing signals, which have the highest coherence and significantly different RMS from others. However, the result we achieved was that: the smaller the window size the more signal the correction removed. Furthermore, when we conducted the same procedures using 10 other DEMs (i.e. DEMs of other places), we found the wrong DEMs also removed signals at a similar level of success to the correct DEM. In only 3 interferograms could we separate the correct DEM from the wrong ones without difficulties. Another thing worth mentioning is the method also removed the real deformation signals, e.g. uplifts and subsidence in the Santa Ana aquifer region. In conclusion then, the DEM-based corrections alone are not sufficient (in most circumstances) to correct for water vapor delay. The incorporation of GPS-derived water vapor delay estimates into these models would be a likely necessary improvement.

Jin, L.; Funning, G. J.; Floyd, M. A.

2009-12-01

158

Using airborne LiDAR and USGS DEM data for assessing rock glaciers and glaciers  

NASA Astrophysics Data System (ADS)

Varying topographic and geologic conditions affect the location of rock glaciers. Despite being found worldwide, rock glaciers are often confused with glacier counterparts or other periglacial landforms. Light detection and ranging (LiDAR) data, because of its accuracy and resolution, may help the assessment of topographic variables needed to form rock glaciers or help reveal unique characteristics to enhance regional, automatic mapping. The objectives of this paper are to compare the elevation, slope, aspect, hillshade, and curvature for 1 m LiDAR and 10 m US Geological Survey (USGS) Digital Elevation Models (DEMs) from the Andrews and Taylor Glaciers with the Taylor Rock Glacier in Colorado. The utility of these data sources will be assessed for landform discrimination and to evaluate the uncertainty between the DEMs. According to the LiDAR data, the Taylor Rock Glacier exists at a lower elevation and has a gentler slope compared to the glaciers. Each landform has steep areas from which snow and debris are delivered. The Andrews Glacier has the most northern aspect, which helps maintain it through snow accumulation and reduced insolation. Glaciers exhibit a concave mean curvature, whereas the Taylor Rock Glacier has a convex mean curvature. The fine resolution of the LiDAR data clearly identifies some distinct characteristics. On the Taylor Rock Glacier, ridges, furrows, and a pronounced front slope were easily identifiable on the LiDAR DEM, whereas crevasses, the boundary between snow and debris covered surfaces, and a lateral moraine were detectable near the Andrews Glacier. The accuracy assessment revealed that at a common 10 m resolution, the USGS DEM estimated a maximum elevation about 150 m greater compared to the LiDAR data in areas of rugged topography surrounding the landforms. A comparison of root mean squared errors (RMSE) between the LiDAR and USGS DEMs showed that the Taylor Rock Glacier has the lowest RMSE for the elevation and the curvature variables. As a result, readily available USGS DEMs may better for analysis to characterize the topographic setting of landforms at the regional scale. At the fine scale, however, the micro-topography of rock glaciers is illuminated much more clearly on the LiDAR data, making it an ideal, yet costly source, for feature extraction.

Janke, Jason R.

2013-08-01

159

DEM generation and tidal deformation detection for sulzberger ice shelf, West Antarctica using SAR interferometry  

USGS Publications Warehouse

In this study we generated a relative Digital Elevation Model (DEM) over the Sulzberger Ice Shelf, West Antarctica using ERS1/2 synthetic aperture radar (SAR) interferometry data. Four repeat pass differential interferograms are used to find the grounding zone and to classify the study area. An interferometrically derived DEM is compared with laser altimetry profile from ICESat. Standard deviation of the relative height difference is 5.12 m and 1.34 m in total length of the profile and at the center of the profile respectively. The magnitude and the direction of tidal changes estimated from interferogram are compared with those predicted tidal differences from four ocean tide models. Tidal deformation measured in InSAR is -16.7 cm and it agrees well within 3 cm with predicted ones from tide models.

Baek, S.; Kwoun, O.-I.; Bassler, M.; Lu, Z.; Shum, C.K.; Dietrich, R.

2004-01-01

160

A comparison of algorithms used to compute hill slope as a property of the DEM  

NASA Astrophysics Data System (ADS)

The calculation of hill slope in the form of downhill gradient and aspect for a point in a digital elevation model (DEM), is a popular procedure in the hydrological, environmental and remote sensing. The most commonly used slope calculation algorithms employed on DEM topography data make use of a three by three search window, or kernel, centred on the grid point (grid cell) in question in order to calculate the gradient and aspect at that point. A comparison of eight frequently used slope calculation algorithms for digital elevation matrices has been carried out using both synthetic and real data as test surfaces. Morrison's surface III, a trigonometrically defined surface, was used as the synthetic test surface. This was differentiated analytically to give true gradient and aspect values against which to compare the results of the tested algorithms. The results of the best-performing slope algorithm on Morrison's surface were then used as the reference against which to compare the other tested algorithms on a real DEM. For both of the test surfaces residual gradient and aspect grids were calculated by subtracting the gradient and aspect grids produced by the algorithms on test from the true/reference gradient and aspect grids. The resulting residual gradient and aspect grids were used to calculate root-mean-square (RMS) residual error estimates that were used to rank the slope algorithms from "best" (lowest value of RMS residual error) to "worst" (largest value of RMS residual error). For Morrison's test surface, Fleming and Hoffer's method gave the "best" results for both gradient and aspect. Horn's method (used in ArcInfo GRID) also performed well for both gradient and aspect estimation. However, the popular maximum downward gradient method (MDG) performed poorly, coming last in the rankings. A similar pattern was seen in the gradient and aspect rankings derived using the Rhum DEM, with Horn's method performing well and the MDG method poorly.

Jones, Kevin H.

1998-05-01

161

A 'Drift' algorithm for integrating vector polyline and DEM based on the spherical DQG  

NASA Astrophysics Data System (ADS)

The efficient integration method of vector and DEM data on a global scale is one of the important issues in the community of Digital Earth. Among the existing methods, geometry-based approach maintains the characteristics of vector data necessary for inquiry and analysis. However, the complexity of geometry-based approach, which needs lots of interpolation calculation, limits its applications greatly in the multi-source spatial data integration on a global scale. To overcome this serious deficiency, a novel 'drift' algorithm is developed based on the spherical Degenerate Quadtree Grid (DQG) on which the global DEMs data is represented. The main principle of this algorithm is that the vector node in a DQG cell can be moved to the cell corner-point without changing the visualization effects if the cell is smaller or equal to a pixel of screen. A detailed algorithm and the multi-scale operation steps are also presented. By the 'drift' algorithm, the vector polylines and DEM grids are integrated seamlessly, avoiding lots of interpolation calculating. Based on the approach described above, we have developed a computer program in platform OpenGL 3D API with VC++ language. In this experiment, USGS GTOPO30 DEM data and 1:1,000,000 DCW roads data sets in China area are selected. Tests have shown that time consumption of the 'drift' algorithm is only about 25% of that of the traditional ones, moreover, the mean error of drift operation on vector nodes can be controlled within about half a DQG cell. In the end, the conclusions and future works are also given.

Wang, Jiaojiao; Wang, Lei; Cao, Wenmin; Zhao, Xuesheng

2014-03-01

162

Von und ber Albert Einstein aus dem Bibliotheksbestand des kiz der Universitt Ulm  

E-print Network

Von und über Albert Einstein aus dem Bibliotheksbestand des kiz der Universität Ulm Titel Autor Synthese Madary, Carl Alberti 1921 J96: B 3500/1921 M Akademie-Vorträge Einstein, Albert Treder, Hans- Jürgen Akademie-Verl. 1979 BZ: p QC 3/1979 E Ex.2 W: p QC 3/1979 E Albert Einstein: sein Einflu� auf

Pfeifer, Holger

163

An Integrated Approach to Accurate dem Generartion Using Airboren Full Waveform LIDAR Data  

NASA Astrophysics Data System (ADS)

In this study, full waveform LiDAR data were exploited to improve the generation of a large-scale digital elevation model (DEM). Building on the methods of progressive generation of triangulation irregular network (TIN) model reported in the literature, we proposed an integrated approach. In this method, echo detection, terrain identification, and TIN generation were performed synergically and iteratively, instead of their separate determinations as in most DEM generation methods. This method started with a TIN model made up of terrain points detected using a morphological opening operation and a curve matching method. For any given TIN facet, the full waveforms of the return associated with the laser pulses interacting with this TIN facet were examined near the surface for any terrain echoes. The TIN was then updated using the newly detected terrain points. These processes were iterated until no new terrain points were identified. The developed method was tested on a data set collected by a Riegl LMS Q-560 scanner over a study area near Sault Ste. Marie, Ontario, Canada (46°33'56''N, 83°25'18''W). The results demonstrated that 30% more terrain points were identified under shrubs and trees using this integrated approach, compared with the commonly used Gaussian decomposition method. The DEMs generated by the developed method exhibited more details in the terrain for two test sites than those obtained by using the TerraScan software.

Hu, B.; Gumerov, D.; Wang, J.-G.

2011-09-01

164

Applying DEM-SRTM for reconstructing a late Quaternary paleodrainage in Amazonia  

NASA Astrophysics Data System (ADS)

Remote sensing is a particularly invaluable tool that has helped the detection of paleomorphologies produced by river dislocation in a variety of landscapes, which has contributed in reconstructing the geological evolution of many fluvial systems. This technique might provide useful information to discuss the evolution of large fluvial systems, in special those located in areas of difficult access where the acquisition of field data is difficult. Application of remote sensing for paleodrainage characterization in densely vegetated tropical areas is scarce in the literature. This work records processing of the Digital Elevation Model (DEM) derived from the Shuttle Radar Topography Mission (SRTM), which succeeded in revealing an ancient drainage complex of the Madeira River, one of the main Amazonas tributaries, where other remote sensing products failed the detection. Analysis of this paleodrainage and of its modern counterpart within the geological framework available for this region leads to propose that activity along pre-existent faults during the latest Quaternary would have promoted the southeastward dislocation of a nearly 200 km long segment of the Madeira River. During this process, an impressive paleodrainage network was left behind, which was only able to be detected using the DEM-SRTM. Application of this technique might be of great help to the detection of paleodrainage morphologies in densely vegetated areas similar to the Amazonas lowland. The dynamics of channel migration in this and many other large scale tropical river systems might benefit from the investigation based on data derived from DEM-SRTM.

Hayakawa, Ericson H.; Rossetti, Dilce F.; Valeriano, Márcio M.

2010-08-01

165

A Review of Discrete Element Method (DEM) Particle Shapes and Size Distributions for Lunar Soil  

NASA Technical Reports Server (NTRS)

As part of ongoing efforts to develop models of lunar soil mechanics, this report reviews two topics that are important to discrete element method (DEM) modeling the behavior of soils (such as lunar soils): (1) methods of modeling particle shapes and (2) analytical representations of particle size distribution. The choice of particle shape complexity is driven primarily by opposing tradeoffs with total number of particles, computer memory, and total simulation computer processing time. The choice is also dependent on available DEM software capabilities. For example, PFC2D/PFC3D and EDEM support clustering of spheres; MIMES incorporates superquadric particle shapes; and BLOKS3D provides polyhedra shapes. Most commercial and custom DEM software supports some type of complex particle shape beyond the standard sphere. Convex polyhedra, clusters of spheres and single parametric particle shapes such as the ellipsoid, polyellipsoid, and superquadric, are all motivated by the desire to introduce asymmetry into the particle shape, as well as edges and corners, in order to better simulate actual granular particle shapes and behavior. An empirical particle size distribution (PSD) formula is shown to fit desert sand data from Bagnold. Particle size data of JSC-1a obtained from a fine particle analyzer at the NASA Kennedy Space Center is also fitted to a similar empirical PSD function.

Lane, John E.; Metzger, Philip T.; Wilkinson, R. Allen

2010-01-01

166

Detection and evaluation on phosphorite mining environment contamination sources using ASTER and DEM  

NASA Astrophysics Data System (ADS)

The main environment contamination source of the phosphorite mining area, located in Huji city, Hubei province, China, was detected and evaluated using ASTER and DEM. Firstly, the featured spectrum that has unique diagnose spectral feature was generalized after analyzing the types and spectrum characteristics of the sample contamination source in the area. Secondly, the main contamination source of the area was recognized by means of principal component analysis using ASTER band 1-9. And the distributions of them were in accordance with that of phosphorite, carbonate and waste water. Finally, flow accumulation and catchment images were simulated using DEM and GIS. By analyzing the images of the flow accumulation, catchment and contamination source, the authors conclude that large scale opencast phosphorite mining and solid waste materials have damaged mining environment; the disordered piling of solid waste material has been boosting diffusion and migration of harmful and toxic matters; and all of these has damaged heavily ecological environment of lower reaches, and is the potential unsafe factor for that of Hanjiang river also. Keywords: ASTER, DEM, mining contamination, detection and evaluation on contamination sources 1.

Chen, Wei-tao; Zhang, Zhi; Li, Zhi-zhong; Yang, Jun-jie; Qian, Li-ping

2008-11-01

167

A Seamless, High-Resolution, Coastal Digital Elevation Model (DEM) for Southern California  

USGS Publications Warehouse

A seamless, 3-meter digital elevation model (DEM) was constructed for the entire Southern California coastal zone, extending 473 km from Point Conception to the Mexican border. The goal was to integrate the most recent, high-resolution datasets available (for example, Light Detection and Ranging (Lidar) topography, multibeam and single beam sonar bathymetry, and Interferometric Synthetic Aperture Radar (IfSAR) topography) into a continuous surface from at least the 20-m isobath to the 20-m elevation contour. This dataset was produced to provide critical boundary conditions (bathymetry and topography) for a modeling effort designed to predict the impacts of severe winter storms on the Southern California coast (Barnard and others, 2009). The hazards model, run in real-time or with prescribed scenarios, incorporates atmospheric information (wind and pressure fields) with a suite of state-of-the-art physical process models (tide, surge, and wave) to enable detailed prediction of water levels, run-up, wave heights, and currents. Research-grade predictions of coastal flooding, inundation, erosion, and cliff failure are also included. The DEM was constructed to define the general shape of nearshore, beach and cliff surfaces as accurately as possible, with less emphasis on the detailed variations in elevation inland of the coast and on bathymetry inside harbors. As a result this DEM should not be used for navigation purposes.

Barnard, Patrick L.; Hoover, Daniel

2010-01-01

168

Extraction of hydrological proximity measures from DEMs using parallel Teklu K. Tesfa a,*, David G. Tarboton b  

E-print Network

: Digital elevation model analysis Flow distance Hydrological proximity measures Message passing interface important terrain properties which impact hydrological, geomorphological, and ecological processes active efficient analysis of much larger DEMs than were possible using the serial recursive algorithms. The HPMs

Tarboton, David

169

A New Double-band-electrode Channel Flow DEMS Cell: Application for Detecting Product Formation during Methanol Electrooxidation  

SciTech Connect

We present a new double-band-electrode channel flow DEMS (differential electrochemical mass spectrometry) cell and demonstrate its application in mechanistic studies with particular relevance to fuel cells. The cell is composed of two band electrodes, which serve as working and detecting electrodes, respectively, separated by a porous Teflon membrane. The Teflon membrane serves as the interface between the aqueous solution and vacuum, through which gases and volatile species can be transported. The hydrodynamic electrochemical characteristics and mass spectrometric behavior have been characterized. With this DEMS cell, gaseous and volatile electrochemical products formed at the working electrode are monitored by mass spectrometry, while nonvolatile products can be selectively detected at the detecting (downstream) electrode. Thus, this system can be considered as the DEMS analogue of a rotating ring/disk electrode. As test cases, the electrooxidation of formaldehyde and methanol on carbon supported Pt nanoparticle catalysts have been studied using this new channel flow DEMS cell.

Wang, Hongsen; Rus, Eric; Abruña, Héctor D.

2010-01-01

170

Evaluation of the TanDEM-X Digital Elevation Model by PPP GPS - Analysis and Intermediate Results  

Microsoft Academic Search

SUMMARY From mission TerraSAR-X add-on for Digital Elevation Measurements (TanDEM-X) of the German Space Agency (DLR) a global digital elevation model (DEM) will be derived using satellite SAR interferometry. Two radar satellites (TerraSAR-X and Tandem-X) are going to map the earth in such a resolution and accuracy that was not possible in any earlier missions: the aim is an absolute

Jürgen SCHWEITZER; Bimin ZHENG; Volker SCHWIEGER; Detlev KOSMANN

171

PRECISION ESTIMATION AND GEOMORPHOLOGICAL ANALYSIS OF DEM OF DAMXUNG-YANGBAJAIN TIBET ACQUIRED BY InSAR  

Microsoft Academic Search

Accurate digital elevation model (DEM) can be produced by using interferometric SAR data. The interferometric processing and analyses are carried out for the test area of Damxung-Yangbajain in Tibet using one couple of ERS-1\\/2 tandem SAR images acquired on April 6, 1996, and on April 7, 1996, respectively. And a portion of the interferometrically derived DEM is selected and compared

Yaqiong DAI; Jinwei REN; Xuhui SHEN; Jingfa ZHANG; Shunying HONG; Yi LUO

172

Use of thermal infrared pictures for retrieving intertidal DEM by the waterline method: advantages and limitations  

NASA Astrophysics Data System (ADS)

Digital Elevation Models (DEM) of the intertidal zones have a growing interest for ecological and land development purposes. They are also a fundamental tool for monitoring current sedimentary movements in those low energy environments. Such DEMs have to be constructed with a centimetric resolution as the topographic changes are not predictable and as sediment displacements are weak. Direct construction of DEM by GPS in these muddy environment is difficult: photogrammetric techniques are not efficient on uniform coloured surfaces and terrestrial laser scans are difficult to stabilize on the mud, due to humidity. In this study, we propose to improve and to apply the waterline method to retrieve DEMs in intertidal zones. This technique is based on monitoring accurately the boundary between sand and water during a whole tide rise with thermal infrared images. The DEM is made by stacking all these lines calibrated by an immersed pressure sensor. Using thermal infrared pictures, instead of optical ones, improves the detection of the waterline, since mud and water have very different responses to sun heating and a large emissivity contrast. However, temperature retrieving from thermal infrared data is not trivial, since the luminance of an object is the sum of a radiative part and a reflexive part, whose relative proportions are given by the emissivity. In the following equation, B accounts for the equivalent blackbody luminance, and Linc is the incident luminance : Ltot}=L{rad}+L_{refl=? B+(1-? )Linc The infrared waterline technique has been used for the monitoring of a beach located on the Aber Benoit, 8.5km away from the open sea. The site is mainly constituted of mud, and waves are very small (less than one centimeter high), which are the ideal conditions for using the waterline method. A few measurements have been made to make differential heigh maps of sediments. We reached a mean resolution of 2cm and a vertical accuracy better than one centimeter. The results have been validated by terrestrial laser scanning. We discuss here the main sources of error due to the very high resolution and suggest methods to minimize its effects : diffuse limit between water and mud due to the heating delay, the difficulty to precisely calibrate thermal camera optics, effects of light reflexion from clouds or cliffs. This technique may be used in the future with satellites, planes or unmanned platforms images, to cover extended areas.

Gaudin, D.; Delacourt, C.; Allemand, P.

2010-12-01

173

DEM modelling, vegetation characterization and mapping of aspen parkland rangeland using LIDAR data  

NASA Astrophysics Data System (ADS)

Detailed geographic information system (GIS) studies on plant ecology, animal behavior and soil hydrologic characteristics across spatially complex landscapes require an accurate digital elevation model (DEM). Following interpolation of last return LIDAR data and creation of a LIDAR-derived DEM, a series of 260 points, stratified by vegetation type, slope gradient and off-nadir distance, were ground-truthed using a total laser station, GPS, and 27 interconnected benchmarks. Despite an overall mean accuracy of +2 cm across 8 vegetation types, it created a RMSE (square root of the mean square error) of 1.21 m. DEM elevations were over-estimated within forested areas by an average of 20 cm with a RMSE of 1.05 m, under-estimated (-12 cm, RMSE = 1.36 m) within grasslands. Vegetation type had the greatest influence on DEM accuracy, while off-nadir distance (P = 0.48) and slope gradient (P = 0.49) did not influence DEM accuracy; however, the latter factors did interact (P < 0.10) to effect accuracy. Vegetation spatial structure (i.e., physiognomy) including plant height, cover, and vertical or horizontal heterogeneity, are important factors influencing biodiversity. Vegetation over and understory were sampled for height, canopy cover, and tree or shrub density within 120 field plots, evenly stratified by vegetation formation (grassland, shrubland, and aspen forest). Results indicated that LIDAR data could be used for estimating the maximum height, cover, and density, of both closed and semi-open stands of aspen (P < 0.001). However, LIDAR data could not be used to assess understory (<1.5 m) height within aspen stands, nor grass height and cover. Recognition and mapping of vegetation types are important for rangelands as they provide a basis for the development and evaluation of management policies and actions. In this study, LIDAR data were found to be superior to digital classification schedules for their mapping accuracy in aspen forest and grassland, but not shrubland. No single classification schedule created a high classification accuracy map for all types; however, the integration of LIDAR data and digital images achieved maps with corresponding overall accuracies of 91% and 83.9% with 3 and 8 classes of vegetation.

Su, Guangquan

174

Coupling photogrammetric data with DFN-DEM model for rock slope hazard assessment  

NASA Astrophysics Data System (ADS)

Structural and mechanical analyses of rock mass are key components for rock slope stability assessment. The complementary use of photogrammetric techniques [Poropat, 2001] and coupled DFN-DEM models [Harthong et al., 2012] provides a methodology that can be applied to complex 3D configurations. DFN-DEM formulation [Scholtès & Donzé, 2012a,b] has been chosen for modeling since it can explicitly take into account the fracture sets. Analyses conducted in 3D can produce very complex and unintuitive failure mechanisms. Therefore, a modeling strategy must be established in order to identify the key features which control the stability. For this purpose, a realistic case is presented to show the overall methodology from the photogrammetry acquisition to the mechanical modeling. By combining Sirovision and YADE Open DEM [Kozicki & Donzé, 2008, 2009], it can be shown that even for large camera to rock slope ranges (tested about one kilometer), the accuracy of the data are sufficient to assess the role of the structures on the stability of a jointed rock slope. In this case, on site stereo pairs of 2D images were taken to create 3D surface models. Then, digital identification of structural features on the unstable block zone was processed with Sirojoint software [Sirovision, 2010]. After acquiring the numerical topography, the 3D digitalized and meshed surface was imported into the YADE Open DEM platform to define the studied rock mass as a closed (manifold) volume to define the bounding volume for numerical modeling. The discontinuities were then imported as meshed planar elliptic surfaces into the model. The model was then submitted to gravity loading. During this step, high values of cohesion were assigned to the discontinuities in order to avoid failure or block displacements triggered by inertial effects. To assess the respective role of the pre-existing discontinuities in the block stability, different configurations have been tested as well as different degree of fracture persistency in order to enhance the possible contribution of rock bridges on the failure surface development. It is believed that the proposed methodology can bring valuable complementary information for rock slope stability analysis in presence of complex fractured system for which classical "Factor of Safety" is difficult to express. References • Harthong B., Scholtès L. & F.V. Donzé, Strength characterization of rock masses, using a coupled DEM-DFN model, Geophysical Journal International, doi: 10.1111/j.1365-246X.2012.05642.x, 2012. • Kozicki J & Donzé FV. YADE-OPEN DEM: an open--source software using a discrete element method to simulate granular material, Engineering Computations, 26(7):786-805, 2009 • Kozicki J, Donzé FV. A new open-source software developed for numerical simulations using discrete modeling methods, Comp. Meth. In Appl. Mech. And Eng. 197:4429-4443, 2008. • Poropat, G.V., New methods for mapping the structure of rock masses. In Proceedings, Explo 2001, Hunter Valley, New South Wales, 28-31 October 2001, pp. 253-260, 2001. • Scholtès, L. & Donzé FV. Modelling progressive failure in fractured rock masses using a 3D discrete element method, International Journal of Rock Mechanics and Mining Sciences, 52:18-30, 2012a. • Scholtès, L. & Donzé, F.-V., DEM model for soft and hard rocks: role of grain interlocking on strength, J. Mech. Phys. Solids, doi: 10.1016/j.jmps.2012.10.005, 2012b. • Sirovision, Commonwealth Scientific and Industrial Research Organisation CSIRO, Siro3D Sirovision 3D Imaging Mapping System Manual Version 4.1, 2010

Donze, Frederic; Scholtes, Luc; Bonilla-Sierra, Viviana; Elmouttie, Marc

2013-04-01

175

Creating High Quality DEMs of Large Scale Fluvial Environments Using Structure-from-Motion  

NASA Astrophysics Data System (ADS)

During the past decade, advances in survey and sensor technology have generated new opportunities to investigate the structure and dynamics of fluvial systems. Key geomatic technologies include the Global Positioning System (GPS), digital photogrammetry, LiDAR, and terrestrial laser scanning (TLS). The application of such has resulted in a profound increase in the dimensionality of topographic surveys - from cross-sections to distributed 3d point clouds and digital elevation models (DEMs). Each of these technologies have been used successfully to derive high quality DEMs of fluvial environments; however, they often require specialized and expensive equipment, such as a TLS or large format camera, bespoke platforms such as survey aircraft, and consequently make data acquisition prohibitively expensive or highly labour intensive, thus restricting the extent and frequency of surveys. Recently, advances in computer vision and image analysis have led to development of a novel photogrammetric approach that is fully automated and suitable for use with simple compact (non-metric) cameras. In this paper, we evaluate a new photogrammetric method, Structure-from-Motion (SfM), and demonstrate how this can be used to generate DEMs of comparable quality to airborne LiDAR, using consumer grade cameras at low costs. Using the SfM software PhotoScan (version 0.8.5), high quality DEMs were produced for a 1.6 km reach and a 3.3 km reach of the braided Ahuriri River, New Zealand. Photographs used for DEM creation were acquired from a helicopter flying at 600 m and 800 m above ground level using a consumer grade 10.1mega-pixel, non-metric digital camera, resulting in object space resolution imagery of 0.12 m and 0.16 m respectively. Point clouds for the two study reaches were generated using 147 and 224 photographs respectively, and were extracted automatically in an arbitrary coordinate system; RTK-GPS located ground control points (GCPs) were used to define a 3d non-linear transformation to convert the point clouds to the absolute NZTM coordinate system, with average errors of 0.06 m in the horizontal and 0.11 m in the vertical dimensions. The final point clouds extracted had typical point spacings of 0.25 m, well above the metric resolution of airborne LiDAR. To improve data handling, the final point cloud was decimated to point spacings of 0.5 m using a recently developed gridding procedure (Rychkov, Brasington, & Vericat, 2012), and finally converted into a DEM using a Delaunay constrained TIN in ArcGIS. Results reveal SfM's ability to produce high quality terrain products of large scale fluvial environments that can outperform LiDAR, and can potentially compare with TLS. PhotoScan offers a straightforward method to generate, transform, and export DEMs that requires little user knowledge of photogrammetric processes. Further, the affordability and reduced field work offer low budget researchers the ability to produce repeat surveys for in-depth temporal studies. Funding supported by the New Zealand Department of Conservation.

Javernick, L. A.; Brasington, J.; Caruso, B. S.; Hicks, M.; Davies, T. R.

2012-12-01

176

Computer vision: automating DEM generation of active lava flows and domes from photos  

NASA Astrophysics Data System (ADS)

Accurate digital elevation models (DEMs) form fundamental data for assessing many volcanic processes. We present a photo-based approach developed within the computer vision community to produce DEMs from a consumer-grade digital camera and freely available software. Two case studies, based on the Volcán de Colima lava dome and the Puyehue Cordón-Caulle obsidian flow, highlight the advantages of the technique in terms of the minimal expertise required, the speed of data acquisition and the automated processing involved. The reconstruction procedure combines structure-from-motion and multi-view stereo algorithms (SfM-MVS) and can generate dense 3D point clouds (millions of points) from multiple photographs of a scene taken from different positions. Processing is carried out by automated software (e.g. http://blog.neonascent.net/archives/bundler-photogrammetry-package/). SfM-MVS reconstructions are initally un-scaled and un-oriented so additional geo-referencing software has been developed. Although this step requires the presence of some control points, the SfM-MVS approach has significantly easier image acquisition and control requirements than traditional photogrammetry, facilitating its use in a broad range of difficult environments. At Colima, the lava dome surface was reconstructed from recent and archive images taken from light aircraft over flights (2007-2011). Scaling and geo-referencing was carried out using features identified in web-sourced ortho-imagery obtained as a basemap layer in ArcMap - no ground-based measurements were required. Average surface measurement densities are typically 10-40 points per m2. Over mean viewing distances of ~500-2500 m (for different surveys), RMS error on the control features is ~1.5 m. The derived DEMs (with 1-m grid resolution) are sufficient to quantify volumetric change, as well as to highlight the structural evolution of the upper surface of the dome following an explosion in June 2011. At Puyehue Cordón-Caulle, images of the active lava flow were taken on foot from a ridge overlooking the flow. To assess the evolution of the flow front, two DEMs were derived from collections of ~400 images taken on different days. To scale and geo-reference the data, one image sequence was accompanied by simultaneous collection of a GPS track using a consumer handheld GPS unit; no control points were used. The second survey was then scaled and georeferenced to the first, using features identifiable in both image sets, giving an RMS error of ~0.22 m. DEM comparison then allows advance rates and mechanisms to be identified, and comparisons drawn with emplacement processes of basaltic flows. In both case studies, the SfM-MVS approach allowed DEM generation when access or lack of dedicated surveying equipment and expertise prevented standard techniques from being deployed.olima dome 2011: 3D point cloud data

James, M. R.; Varley, N. R.; Tuffen, H.

2012-12-01

177

Evaluation of Elevation, Slope and Stream Network Quality of SPOT Dems  

NASA Astrophysics Data System (ADS)

Digital elevation models are considered the most useful data for dealing with geomorphology. The quality of these models is an important issue for users. This quality concerns position and shape. Vertical accuracy is the most assessed in many studies and shape quality is often neglected. However, both of them have an impact on the quality of the final results for a particular application. For instance, the elevation accuracy is required for orthorectification and the shape quality for geomorphology and hydrology. In this study, we deal with photogrammetric DEMs and show the importance of the quality assessment of both elevation and shape. For this purpose, we produce several SPOT HRV DEMs with the same dataset but with different template size, that is one of the production parameters from optical images. Then, we evaluate both elevation and shape quality. The shape quality is assessed with in situ measurements and analysis of slopes as an elementary shape and stream networks as a complex shape. We use the fractal dimension and sinuosity to evaluate the stream network shape. The results show that the elevation accuracy as well as the slope accuracy are affected by the template size. Indeed, an improvement of 1 m in the elevation accuracy and of 5 degrees in the slope accuracy has been obtained while changing this parameter. The elevation RMSE ranges from 7.6 to 8.6 m, which is smaller than the pixel size (10 m). For slope, the RMSE depends on the sampling distance. With a distance of 10 m, the minimum slope RMSE is 11.4 degrees. The stream networks extracted from these DEMs present a higher fractal dimension than the reference river. Moreover, the fractal dimension of the extracted networks has a negligible change according to the template size. Finally, the sinuosity of the stream networks is slightly affected by the change of the template size.

El Hage, M.; Simonetto, E.; Faour, G.; Polidori, L.

2012-07-01

178

Appointments at a thyroid outpatient clinic and the lunar cycle  

Microsoft Academic Search

\\u000a Zusammenfassung\\u000a Einleitung  Der Einfluss des Mondes auf die menschliche Psyche fasziniert sowohl Wissenschaftler als auch Laien seit Jahrhunderten; zahlreiche\\u000a Variablen wurden hinsichtlich eines möglichen Zusammenhangs mit den Mondphasen untersucht. Ziel dieser Studie war es abzuklären,\\u000a ob ein Zusammenhang zwischen der Anzahl an Terminanfragen an einer Spitalsambulanz und den Mondphasen besteht. Dieser Parameter\\u000a wurde mit fundierten wissenschaftlichen Methoden bisher noch nie untersucht.

Georg Zettinig; Richard Crevenna; Christian Pirich; Robert Dudczak; Thomas Waldhoer

2003-01-01

179

DEM L241, A SUPERNOVA REMNANT CONTAINING A HIGH-MASS X-RAY BINARY  

SciTech Connect

A Chandra observation of the Large Magellanic Cloud supernova remnant DEM L241 reveals an interior unresolved source which is probably an accretion-powered binary. The optical counterpart is an O5III(f) star making this a high-mass X-ray binary with an orbital period likely to be of the order of tens of days. Emission from the remnant interior is thermal and spectral information is used to derive density and mass of the hot material. Elongation of the remnant is unusual and possible causes of this are discussed. The precursor star probably had mass >25 M {sub Sun}.

Seward, F. D. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Charles, P. A. [School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Foster, D. L. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935, Cape Town (South Africa); Dickel, J. R.; Romero, P. S. [Department of Physics and Astronomy, University of New Mexico, 1919 Lomas Boulevard NE, Albuquerque, NM 87131 (United States); Edwards, Z. I.; Perry, M.; Williams, R. M. [Department of Earth and Space Sciences, Columbus State University, Coca Cola Space Science Center, 701 Front Avenue, Columbus, GA 31901 (United States)

2012-11-10

180

The research by topographic correction methods of airborne hyperspectral remote sensing data based on DEM  

NASA Astrophysics Data System (ADS)

High spectral resolution is the main characteristic of hyperspectral remote sensing. The image of objects includes various information of space, radiation and spectral information, and we can also construct a continuous spectrum curve in the imaging range. The purpose of topographic correction is to eliminate the effects of solar light , which may make the spectral curve not accurate compared with the practical curve, on radiation values of irregular ground object. This paper is to analysis the advantages and disadvantages of various topographic correction methods, and provide accurate experimental data for quantitative remote sensing, which based on the area of airborne hyperspectral remote sensing image and DEM, comparing with the measured spectral curve.

Liu, Chunfeng; Li, Na; Li, Xudong; Zhao, Huijie

2014-12-01

181

Multi-frequency study of DEM L299 in the Large Magellanic Cloud  

NASA Astrophysics Data System (ADS)

Aims: We have studied the H ii region DEM L299 in the Large Magellanic Cloud (LMC) to understand its physical characteristics and morphology in different wavelengths. Methods: We performed a spectral analysis of archived XMM-Newton EPIC data and studied the morphology of DEM L299 in X-ray, optical, and radio wavelengths. We used H?, [S ii], and [O iii] data from the Magellanic Cloud Emission Line Survey (MCELS) and radio 21 cm line data from the Australia Telescope Compact Array (ATCA) and the Parkes Telescope as well as radio continuum data (3 cm, 6 cm, 20 cm, 36 cm) from ATCA and from the Molonglo Synthesis Telescope (MOST). Results: Our morphological studies imply that, in addition to the supernova remnant SNR B0543-68.9 reported in previous studies, a superbubble also overlaps the SNR in projection. The position of the SNR is clearly defined through the [S ii]/H? flux ratio image. Moreover, the optical images show a shell-like structure that is located farther to the north and is filled with diffuse X-ray emission, which again indicates the superbubble. Radio 21 cm line data show a shell around both objects. Radio continuum data show diffuse emission at the position of DEM L299, which appears clearly distinguished from the H ii region LHA 120-N 164 that lies south-west of it. We determined the spectral index of SNR B0543-68.9 to be ? = -0.34, which indicates the dominance of thermal emission and therefore a rather mature remnant. We determined the basic properties of the diffuse X-ray emission for the SNR, the superbubble, and a possible blowout region of the bubble, as suggested by the optical and X-ray data. We obtained an age of (8.9+9.2-5.4) kyr for the SNR and a temperature of (0.64+0.73-0.20) keV for the hot gas inside the SNR, as well as a thermal energy content and temperature of the hot gas inside the superbubble of (4.3+8.1-2.6) × 1050 ?0.5 erg and (0.74+0.36-0.30) keV, with ? being the gas-filling factor. Conclusions: We conclude that DEM L299 consists of a superposition of SNR B0543-68.9 and a superbubble, which we identified based on optical data. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA member states and NASA.

Warth, Gabriele; Sasaki, Manami; Kavanagh, Patrick J.; Filipovi?, Miroslav D.; Points, Sean D.; Bozzetto, Luke M.

2014-07-01

182

A study of evolution of near-earth daemon's fluxes with using Dark Electron Multipliers (DEMs)  

E-print Network

DEMs have been used to experimental studying the temporal evolution of the March maximum of fluxes of near-Earth daemons. It is shown that part of objects from near-Earth almost circular heliocentric orbits (NEACHOs), from which a rather intense flux proceeds during only about four weeks, forms in the second half of March the population in geocentric Earth-surface-crossing orbits (GESCOs). The resistance of the Earth's matter results in that GESCO objects sink into the Earth's interior, so that the GESCO population nearly disappears by the end of April.

E. M. Drobyshevski; M. E. Drobyshevski; S. A. Ponyaev

2012-06-04

183

Diagnose und Evaluierung von Makulaforamina mit dem HRT 2 Retina Modul  

Microsoft Academic Search

Zusammenfassung\\u000a Hintergrund  Ziel dieser prospektiven Studie ist die Evaluation des HRT 2 Retina Moduls als Untersuchungsmethode für Makulaforamina. Wir\\u000a beurteilen außerdem den Einfluss von präoperativen Befunden auf die postoperativen funktionellen und anatomischen Ergebnisse.\\u000a Die Messungen mit dem Heidelberger Retina Tomograph wurden mit optischer Kohärenztomographie (OCT III) und spektraler optischer\\u000a Kohärenztomographie (SOCT) verglichen.\\u000a \\u000a \\u000a \\u000a Material und Methode  Es wurden prä- und postoperative Daten von

Z. Michalewska; J. Michalewski; J. Nawrocki

2007-01-01

184

Optical-radar-DEM remote sensing data integration for geological mapping in the Afar Depression, Ethiopia  

NASA Astrophysics Data System (ADS)

The advantages of integrating optical (Landsat Enhanced Thematic Mapper Plus (ETM+) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)) and radar (Shuttle Imaging Radar (SIR) - C, X-band Synthetic Aperture Radar (SAR) and RADARSAT-1) remote sensing data, and digital elevation models (DEMs) (Shuttle Radar Topography Mission (SRTM)) for geological mapping in arid regions such as the Afar Depression in Ethiopia are demonstrated. The Afar Depression in NE Africa is a natural laboratory for studying processes of sea-floor spreading and the transition from rifting to true sea-floor spreading. It is ideal for geological remote sensing because of its vastness, remoteness and inaccessibility together with almost continuous exposure, and lack of vegetation and soil cover. Optical-radar-DEM remote sensing data integration is used for: (1) Distinguishing spatial and temporal distribution of individual lava flows in the Quaternary Erta 'Ale Volcanic Range in the northern part of the Afar Depression, by integrating band-ratios of ASTER thermal infrared (TIR) data with Landsat ETM+ visible and near infrared (VNIR) and SIR-C/X-SAR L-band ( ? = 24 cm) data with horizontally transmitted and horizontally received (HH) polarization. (2) Visualizing and interpreting extensional imbrication fans that constitute part of the Dobe Graben in the central part of the Afar Depression by integrating Landsat ETM+ VNIR data with RADARSAT C-band ( ? = 6 cm) data with HH polarization and SRTM DEMs. These imbrication fans were developed as layer-parallel gravitational slip of the border fault hanging-wall towards the graben center. (3) Mapping morphologically defined structures in rhyolite flows exposed on the flanks of the Tendaho Rift by merging ASTER VNIR and short wave infrared (SWIR) with RADARSAT C-band data with HH polarization. The Tendaho Rift constitutes part of the Tendaho-Gobaad Discontinuity that separates the southern and the central eastern parts of the Afar Depression. Optical-radar-DEM data integration proved to be an effective approach for aiding geological mapping and structural analysis in arid regions such as the Afar Depression.

Thurmond, Allison K.; Abdelsalam, Mohamed G.; Thurmond, John B.

2006-02-01

185

Comparison of elevation derived from insar data with dem from topography map in Son Dong, Bac Giang, Viet Nam  

NASA Astrophysics Data System (ADS)

Digital Elevation Models (DEMs) are used in many applications in the context of earth sciences such as in topographic mapping, environmental modeling, rainfall-runoff studies, landslide hazard zonation, seismic source modeling, etc. During the last years multitude of scientific applications of Synthetic Aperture Radar Interferometry (InSAR) techniques have evolved. It has been shown that InSAR is an established technique of generating high quality DEMs from space borne and airborne data, and that it has advantages over other methods for the generation of large area DEM. However, the processing of InSAR data is still a challenging task. This paper describes InSAR operational steps and processing chain for DEM generation from Single Look Complex (SLC) SAR data and compare a satellite SAR estimate of surface elevation with a digital elevation model (DEM) from Topography map. The operational steps are performed in three major stages: Data Search, Data Processing, and product Validation. The Data processing stage is further divided into five steps of Data Pre-Processing, Co-registration, Interferogram generation, Phase unwrapping, and Geocoding. The Data processing steps have been tested with ERS 1/2 data using Delft Object-oriented Interferometric (DORIS) InSAR processing software. Results of the outcome of the application of the described processing steps to real data set are presented.

Nguyen, Duy

2012-07-01

186

Application of the PROMETHEE technique to determine depression outlet location and flow direction in DEM  

NASA Astrophysics Data System (ADS)

With the fast growing progress of computer technologies, spatial information on watersheds such as flow direction, watershed boundaries and the drainage network can be automatically calculated or extracted from a digital elevation model (DEM). The stubborn problem that depressions exist in DEMs has been frequently encountered while extracting the spatial information of terrain. Several filling-up methods have been proposed for solving depressions. However, their suitability for large-scale flat areas is inadequate. This study proposes a depression watershed method coupled with the Preference Ranking Organization METHod for Enrichment Evaluations (PROMETHEEs) theory to determine the optimal outlet and calculate the flow direction in depressions. Three processing procedures are used to derive the depressionless flow direction: (1) calculating the incipient flow direction; (2) establishing the depression watershed by tracing the upstream drainage area and determining the depression outlet using PROMETHEE theory; (3) calculating the depressionless flow direction. The developed method was used to delineate the Shihmen Reservoir watershed located in Northern Taiwan. The results show that the depression watershed method can effectively solve the shortcomings such as depression outlet differentiating and looped flow direction between depressions. The suitability of the proposed approach was verified.

Chou, Tien-Yin; Lin, Wen-Tzu; Lin, Chao-Yuan; Chou, Wen-Chieh; Huang, Pi-Hui

2004-02-01

187

Effect of cohesion on granular-fluid flows in spouted beds: PIV measurement and DEM simulations  

NASA Astrophysics Data System (ADS)

In contrast to wet granular flows, the effect of cohesion on complex granular-fluid flows is intriguing but much challenging. The liquid bridges, forming between binary particles with the addition of a small amount of liquids, might significantly change the granular-fluid system due to both cohesion and lubrication effects. In this paper, a spouted bed, among various fluidization technologies, is particularly selected as a prototypical system for studying granular-fluid flows, since it can provide a quasi-steady flow pattern of granular particles, i.e., a core of upward granular-fluid flow called the "spout" and a surrounding region of downward quasi-static granular flow called the "annulus". Firstly, using self-developed particle image velocimetery (PIV) technique, the effects of cohesion on the spout-annulus interface (namely the spout width) and on the particle velocity profiles in distinct zones are examined. Further, the discrete element method (DEM), by incorporating liquid bridge adhesion into soft-sphere model, is established and used to predict the microdynamic behavior of particles in spouted beds. Finally, based on both experiments and DEM validation, the effects on the granular patterns in these two zones are comparatively discussed.

Zhu, Runru; LI, Shuiqing; Yao, Qiang

2013-06-01

188

Supervised landform classification of Northeast Honshu from DEM-derived thematic maps  

NASA Astrophysics Data System (ADS)

This paper proposes a quantitative method to classify landforms using four morphometric parameters from DEM-derived thematic raster maps of slope and topographic openness. Because the different surficial processes and stages in the evolution of slopes create landscapes with different shapes, these parameters may lead to a genetic interpretation of topography. The raster maps of slope and topographic openness were constructed for Northeast Honshu, Japan, from 50-m DEMs. The mean and standard deviation of morphometric parameters within a 3050 m by 3050 m moving window on the raster maps were calculated. The results for some training areas show that constructional/depositional and erosional landforms with different relief have different morphometric characteristics. A supervised landform classification for Northeast Honshu using the knowledge from the training areas revealed a ladder geomorphological structure composed of high mountains, ranges and volcanoes. The close relationship between the ladder geomorphological structure and volcano distribution indicates that the structure reflects the magmatic plumbing system from the upper mantle to the crust of the Northeast Honshu arc.

Prima, Oky Dicky Ardiansyah; Echigo, Ayako; Yokoyama, Ryuzo; Yoshida, Takeyoshi

2006-08-01

189

DEM generation from digital photographs using computer vision: Accuracy and application  

NASA Astrophysics Data System (ADS)

Data for detailed digital elevation models (DEMs) are usually collected by expensive laser-based techniques, or by photogrammetric methods that require expertise and specialist software. However, recent advances in computer vision research now permit 3D models to be automatically derived from unordered collections of photographs, and offer the potential for significantly cheaper and quicker DEM production. Here, we review the advantages and limitations of this approach and, using imagery of the summit craters of Piton de la Fournaise, compare the precisions obtained with those from formal close range photogrammetry. The surface reconstruction process is based on a combination of structure-from-motion and multi-view stereo algorithms (SfM-MVS). Using multiple photographs of a scene taken from different positions with a consumer-grade camera, dense point clouds (millions of points) can be derived. Processing is carried out by automated 'reconstruction pipeline' software downloadable from the internet. Unlike traditional photogrammetric approaches, the initial reconstruction process does not require the identification of any control points or initial camera calibration and is carried out with little or no operator intervention. However, such reconstructions are initially un-scaled and un-oriented so additional software has been developed to permit georeferencing. Although this step requires the presence of some control points or features within the scene, it does not have the relatively strict image acquisition and control requirements of traditional photogrammetry. For accuracy, and to allow error analysis, georeferencing observations are made within the image set, rather than requiring feature matching within the point cloud. Application of SfM-MVS is demonstrated using images taken from a microlight aircraft over the summit of Piton de la Fournaise volcano (courtesy of B. van Wyk de Vries). 133 images, collected with a Canon EOS D60 and 20 mm fixed focus lens, were used to create a ~1.6 km wide DEM covering the summit craters. When compared with a DEM constructed using close-range photogrammetry the SfM-MVS results showed an RMS error of 1.0 m. The overall precision of the project can be considered by ratioing this against the average viewing distance (1000 m). This relative precision of 1:1000 is in line with the results of other projects carried out over a range of spatial scales (down to ~0.1 m), so appears to be a characteristic expected achievable precision for the SfM-MVS approach. Consequently, over shorter viewing distances, absolute precisions increase - e.g. centimeter-level precisions for outcrop-scale studies where viewing distances may be expected to be of order 10 m. Although SfM-MVS cannot deliver the accuracy and precision of formal close-range photogrammetry, it can approach the results that are achievable from single stereo image pairs. However, the main advantages of the technique lie in the enhanced flexibility in image collection and automated processing, both of which significantly decrease the level of expertise required. When compared with terrestrial laser scanning at outcrop scales, the data collection time in the field can be reduced by ~80%. SfM-MVS data quality is sufficient for the technique to provide valuable DEMs of active flows and domes where access to (or for) modern surveying equipment is restricted.

James, M. R.; Robson, S.

2012-12-01

190

BOREAS HYD-8 DEM Data Over the NSA-MSA and SSA-MSA in the UTM Projection  

NASA Technical Reports Server (NTRS)

The BOREAS HYD-8 team focused on describing the scaling behavior of water and carbon flux processes at local and regional scales. These DEMs were produced from digitized contours at a cell resolution of 100 meters. Vector contours of the area were used as input to a software package that interpolates between contours to create a DEM representing the terrain surface. The vector contours had a contour interval of 25 feet. The data cover the BOREAS MSAs of the SSA and NSA and are given in a UTM map projection. Most of the elevation data from which the DEM was produced were collected in the 1970s or 1980s. The data are stored in binary, image format files. The data files are available on a CD-ROM (see document number 20010000884) or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Wang, Xue-Wen; Hall, Forrest G. (Editor); Knapp, David E. (Editor); Band, L. E.; Smith, David E. (Technical Monitor)

2000-01-01

191

Turbidity Current Transport using DEM and FEM: a Hybrid Lagrangian-Eulerian Approach  

NASA Astrophysics Data System (ADS)

In this work we describe a contribution to the study of turbidity transport in scales smaller than TFM (two-fluid models), The intent of the work, part of a large scale simulation project, is to assess local, small scale parameters and their upscaling. The hybrid model is based on a Lagrangian-Eulerian approach under a class of the so called Unresolved Discrete Particle Method (UDPM). In this approach, a Lagrangian description is used for the particle system employing the Discrete Element Method (DEM) while a fixed Eulerian mesh is used for the fluid phase modeled by finite element method (FEM), Fluid motion is governed by Navier-Stokes equations which are solved by an appropriate FEM implementation. Closure equation are used to compute drag and lift forces over the particles in the DEM framework. Volume averaged momentum sink terms are included in the fluid equations. The resulting coupled DEM-FEM model is integrated in time with a subcycling scheme. The aforementioned scheme was applied in the simulation of a sedimentation basin as depicted in figures 1 and 2 to investigate flow and deposition features of the suspension in a finer scale. For this purpose a submodel of the basin was generated. Mapping variables back and forth the Eulerian (finite element) model and the Lagrangian (discrete element) model were performed during the subcycled integration of the hybrid model. References: [1] Hoomans, B.P.B., Kuipers, J.A.M., Swaaij, van W.P.M," Granular dynamics Simulation of segregation phenomena in bubbling gas-fluidised beds", Powder Technology, V 109, Issues 1-3, 3 April 2000, pp 41-48; [2] Cho, S.H., Choi,H.G, Yoo, J.Y.,"Direct numerical simulation of fluid flow laden with many particles", International Journal of Multiphase Flow, V 31, Issue 4, April 2005, pp 435-451;; Sedimentation basin: sectioning the turbidity plume in the Eulerian FE model for setting up the discrete particle model. ; Sedimentation Basin: section of the turbidity plume displaying the generated discrete particle model underneath.

Alves, J. L.; Guevara, N. O., Jr.; Silva, C. E.; Alves, F. T.; Gazoni, L. C.; Coutinho, A.; Camata, J.; Elias, R. N.; Paraizo, P.

2013-05-01

192

Semi-automated extraction of landslides in Taiwan based on SPOT imagery and DEMs  

NASA Astrophysics Data System (ADS)

The vast availability and improved quality of optical satellite data and digital elevation models (DEMs), as well as the need for complete and up-to-date landslide inventories at various spatial scales have fostered the development of semi-automated landslide recognition systems. Among the tested approaches for designing such systems, object-based image analysis (OBIA) stepped out to be a highly promising methodology. OBIA offers a flexible, spatially enabled framework for effective landslide mapping. Most object-based landslide mapping systems, however, have been tailored to specific, mainly small-scale study areas or even to single landslides only. Even though reported mapping accuracies tend to be higher than for pixel-based approaches, accuracy values are still relatively low and depend on the particular study. There is still room to improve the applicability and objectivity of object-based landslide mapping systems. The presented study aims at developing a knowledge-based landslide mapping system implemented in an OBIA environment, i.e. Trimble eCognition. In comparison to previous knowledge-based approaches, the classification of segmentation-derived multi-scale image objects relies on digital landslide signatures. These signatures hold the common operational knowledge on digital landslide mapping, as reported by 25 Taiwanese landslide experts during personal semi-structured interviews. Specifically, the signatures include information on commonly used data layers, spectral and spatial features, and feature thresholds. The signatures guide the selection and implementation of mapping rules that were finally encoded in Cognition Network Language (CNL). Multi-scale image segmentation is optimized by using the improved Estimation of Scale Parameter (ESP) tool. The approach described above is developed and tested for mapping landslides in a sub-region of the Baichi catchment in Northern Taiwan based on SPOT imagery and a high-resolution DEM. An object-based accuracy assessment is conducted by quantitatively comparing extracted landslide objects with landslide polygons that were visually interpreted by local experts. The applicability and transferability of the mapping system are evaluated by comparing initial accuracies with those achieved for the following two tests: first, usage of a SPOT image from the same year, but for a different area within the Baichi catchment; second, usage of SPOT images from multiple years for the same region. The integration of the common knowledge via digital landslide signatures is new in object-based landslide studies. In combination with strategies to optimize image segmentation this may lead to a more objective, transferable and stable knowledge-based system for the mapping of landslides from optical satellite data and DEMs.

Eisank, Clemens; Hölbling, Daniel; Friedl, Barbara; Chen, Yi-Chin; Chang, Kang-Tsung

2014-05-01

193

Jugendkulturen zwischen Globalisierung und Ethnisierung  

Microsoft Academic Search

\\u000a Zusammenfassung  Wie formt sich der Prozess der Globalisierung in den Lebensstilen Jugendlicher aus? Dieser allgemeinen Fragestellung gehen\\u000a wir im folgenden am Beispiel russischer Jugendlicher nach, denn auf der Suche nach Identit?t erfahren russische Jugendliche\\u000a seit der Perestrojka immer st?rker das Kr?ftefeld der westlichen Kultur.\\u000a \\u000a Der folgende Beitrag beschreibt das Verh?ltnis russischer Jugend und Jugendkulturen zur westlichen und schlie?lich zu ihrer\\u000a eigenen

Dirk Villányi; Matthias D. Witte

2004-01-01

194

Mechanical behavior modeling of sand-rubber chips mixtures using discrete element method (DEM)  

NASA Astrophysics Data System (ADS)

Rubber shreds in mixture with sandy soils are widely used in geotechnical purposes due to their specific controlled compressibility characteristics and light weight. Various studies have been carried out for sand or rubber chips content in order to restrain the compressibility of the mass in different structures such as backfills, road embankments, etc. Considering different rubber contents, sand-rubber mixtures can be made which lead mechanical properties of the blend to go through changes. The aim of this paper is to study the effect of adding different rubber portions on the global engineering properties of the mixtures. This study is performed by using Discrete Element Method (DEM). The simulations showed that adding rubber up to a particular fraction can improve maximum bearing stress characteristics comparing to sand alone masses. Taking the difference between sand and rubber stiffness into account, the result interpretation can be developed to other soft and rigid particle mixtures such as powders or polymers.

Eidgahee, Danial Rezazadeh; Hosseininia, Ehsan Seyedi

2013-06-01

195

3DEM Loupe: Analysis of macromolecular dynamics using structures from electron microscopy.  

PubMed

Electron microscopy (EM) provides access to structural information of macromolecular complexes in the 3-20 Å resolution range. Normal mode analysis has been extensively used with atomic resolution structures and successfully applied to EM structures. The major application of normal modes is the identification of possible conformational changes in proteins. The analysis can throw light on the mechanism following ligand binding, protein-protein interactions, channel opening and other functional macromolecular movements. In this article, we present a new web server, 3DEM Loupe, which allows normal mode analysis of any uploaded EM volume using a user-friendly interface and an intuitive workflow. Results can be fully explored in 3D through animations and movies generated by the server. The application is freely available at http://3demloupe.cnb.csic.es. PMID:23671335

Nogales-Cadenas, R; Jonic, S; Tama, F; Arteni, A A; Tabas-Madrid, D; Vázquez, M; Pascual-Montano, A; Sorzano, C O S

2013-07-01

196

MC-DEM: a novel simulation scheme for modeling dense granular media  

E-print Network

This article presents a new force model for performing quantitative simulations of dense granular materials. Interactions between multiple contacts (MC) on the same grain are explicitly taken into account. Our readily applicable method retains all the advantages of discrete element method (DEM) simulations and does not require the use of costly finite element methods. The new model closely reproduces our recent experimental measurements, including contact force distributions in full 3D, at all compression levels up to the experimental maximum limit of 13\\%. Comparisons with traditional non-deformable spheres approach are provided, as well as with alternative models for interactions between multiple contacts. The success of our model compared to these alternatives demonstrates that interactions between multiple contacts on each grain must be included for dense granular packings.

Nicolas Brodu; Joshua A. Dijksman; Robert P. Behringer

2014-10-23

197

Mechanistic Based DEM Simulation of Particle Attrition in a Jet Cup  

SciTech Connect

The attrition of particles is a major industrial concern in many fluidization systems as it can have undesired effects on the product quality and on the reliable operation of process equipment. Therefore, to accomodate the screening and selection of catalysts for a specific process in fluidized beds, risers, or cyclone applications, their attrition propensity is usually estimated through jet cup attrition testing, where the test material is subjected to high gas velocities in a jet cup. However, this method is far from perfect despite its popularity, largely due to its inconsistency in different testing set-ups. In order to better understand the jet cup testing results as well as their sensitivity to different operating conditions, a coupled computational fluid dynamic (CFD) - discrete element method (DEM) model has been developed in the current study to investigate the particle attrition in a jet cup and its dependence on various factors, e.g. jet velocity, initial particle size, particle density, and apparatus geometry.

Xu, Wei; DeCroix, David; Sun, Xin

2014-02-01

198

Revealing topographic lineaments through IHS enhancement of DEM data. [Digital Elevation Model  

NASA Technical Reports Server (NTRS)

Intensity-hue-saturation (IHS) processing of slope (dip), aspect (dip direction), and elevation to reveal subtle topographic lineaments which may not be obvious in the unprocessed data are used to enhance digital elevation model (DEM) data from northwestern Nevada. This IHS method of lineament identification was applied to a mosiac of 12 square degrees using a Cray Y-MP8/864. Square arrays from 3 x 3 to 31 x 31 points were tested as well as several different slope enhancements. When relatively few points are used to fit the plane, lineaments of various lengths are observed and a mechanism for lineament classification is described. An area encompassing the gold deposits of the Carlin trend and including the Rain in the southeast to Midas in the northwest is investigated in greater detail. The orientation and density of lineaments may be determined on the gently sloping pediment surface as well as in the more steeply sloping ranges.

Murdock, Gary

1990-01-01

199

NUMERICAL EXPERIMENTS BY DEM ON INTERMIDIATE PRINCIPAL STRESS AFFECTING 3D SHEAR BEHAVIOR  

NASA Astrophysics Data System (ADS)

It is important to consider the effect of the intermediate principal stress on 3D shear behavior of granular materials, although there are various factors. The objective is to investigate it macro- and micro-mechanically using dense specimen with spherical particles by Distinct Element Method (DEM). It was found that the relationship between the normalized plastic work and the equivalent plastic deviatoric strain is not strictly unique for different b values, and that the directivity of the contacts with relatively large contact force and the constraint condition due to b value cause the deviation of principal deviatoric strain from the linear relation obtained for isotropic and elastic material, and that numerical experimental results coincide with Lade and Duncan's failure criterion, and that there is a unique relationship among the coordination number, the plastic volume and the equivalent plastic deviatoric strain.

Suzuki, Kiichi

200

DEM Simulated Results And Seismic Interpretation of the Red River Fault Displacements in Vietnam  

NASA Astrophysics Data System (ADS)

The Song Hong basin is the largest Tertiary sedimentary basin in Viet Nam. Its onset is approximately 32 Ma ago since the left-lateral displacement of the Red River Fault commenced. Many researches on structures, formation and tectonic evolution of the Song Hong basin have been carried out for a long time but there are still remained some problems that needed to put into continuous discussion such as: magnitude of the displacements, magnitude of movement along the faults, the time of tectonic inversion and right lateral displacement. Especially the mechanism of the Song Hong basin formation is still in controversy with many different hypotheses due to the activation of the Red River fault. In this paper PFC2D based on the Distinct Element Method (DEM) was used to simulate the development of the Red River fault system that controlled the development of the Song Hong basin from the onshore to the elongated portion offshore area. The numerical results show the different parts of the stress field such as compress field, non-stress field, pull-apart field of the dynamic mechanism along the Red River fault in the onshore area. This propagation to the offshore area is partitioned into two main branch faults that are corresponding to the Song Chay and Song Lo fault systems and said to restrain the east and west flanks of the Song Hong basin. The simulation of the Red River motion also showed well the left lateral displacement since its onset. Though it is the first time the DEM method was applied to study the deformation and geodynamic evolution of the Song Hong basin, the results showed reliably applied into the structural configuration evaluation of the Song Hong basin.

Bui, H. T.; Yamada, Y.; Matsuoka, T.

2005-12-01

201

Upscaling water cycle parameters using geomorphometric terrain parameters and topographic indices derived from interferometric DEM  

NASA Astrophysics Data System (ADS)

For assessing a regional water balance in boreal landscapes the extend to which evapo-transpiration is subject to spatial variations needs to be known. Water cycle parameters such as transpiration rates of vegetation are depending on both the vegetation type and hydro-pedologic stand conditions since poor soil drainage respective seasonal soil drought affect water consumption by vegetation. The spatial distribution of the pristine boreal vegetation types can be obtained by SAR or optical remote sensing sensors on a regional scale. Many works have been dealing with this subject in the past and it is widely known how remote sensing can contribute to vegetation mapping. To assess hydro-pedologic stand conditions on a regional scale an alternative method is required. Our approach to resolve this problem is based on the fact that soil water status is essentially a function of topographic properties. For that reason morphometric terrain parameters derived from a Digital Elevation Model (DEM) has been used to indicate regions with homogeneous hydro-pedologic stand conditions, so called "hydropedotopes". To delineate the required hydropedotopes two indicators pertaining to soilwater status and pedo-hydrology were derived from InSAR DEM: (1) The wetness-index and (2) the vertical distance to streams and bottom lines. In a further step the resulting map of hydropedotopes is intersected with a remote sensing derived map of the actual spatial distribution of the boreal vegetation types. This step results in a map which marks out landscape units of homogeneous properties in terms of vegetation type and hydro-pedologic conditions which is the basis for upscaling canopy transpiration measurements. From our approach which uses in addition to conventional remote sensing data the results of an automated digital terrain analysis we expect a substantially enhanced knowledge of the spatial variability of water flux rates conditional on canopy transpiration. The process of our approach at a glance is illustrated.

Etzrodt, N.; Zimmermann, R.; Conrad, O.

2002-01-01

202

Analysis of initial drainage network evolution from aerial photography and a DEM time series  

NASA Astrophysics Data System (ADS)

The evolution of erosion rill or gully networks is a formative process in initial landscape development. Digital representations of drainage networks are often derived from Digital Elevation Models (DEMs) based on morphometric parameters, or mapped in field surveys or from aerial photographs. This study attempted to reconstruct and analyze the first five years of erosion rill network evolution in the 6 ha artificial catchment 'Hühnerwasser', which serves as a real world-laboratory to study patterns and processes of initial ecosystem development. The drainage network was characterized in a twofold approach, based on the analysis of remotely-sensed data. We used high-resolution drone-based aerial photographs to map the actively eroding rill network for four states of development, and a time series of ten Digital Elevation Models to characterize the morphology of the surface. Rill network maps and morphometric parameters were combined to allow for region-specific analyses of morphometry for different parts of the rill network. After a rapid growth of the erosion rill network during the first two years of development, a reduction of the area of actively eroding rills was observed. Region-specific analysis of morphometry indicates an increase in flow accumulation in the central parts of the rill network, which suggests that locally evolving feedback cycles between flow accumulation and erosion affected rill network development, in addition to the effects of precipitation characteristics and the growth of vegetation cover. The combination of drainage network characterization from aerial photography and DEMs could improve analyses of initial drainage network development in experimental studies, as it allows for critical comparisons of flow accumulation patterns and the actual patterns of erosion rills or gullies.

Schneider, Anna; Gerke, Horst H.; Maurer, Thomas; Nenov, Rossen; Raab, Thomas

2013-04-01

203

Open Source MFIX-DEM Software for Gas-Solids Flows: Part 1 - Verification Studies  

SciTech Connect

With rapid advancements in computer hardware, it is now possible to perform large simulations of granular flows using the Discrete Element Method (DEM). As a result, solids are increasingly treated in a discrete Lagrangian fashion in the gas–solids flow community. In this paper, the open-source MFIX-DEM software is described that can be used for simulating the gas–solids flow using an Eulerian reference frame for the continuum fluid and a Lagrangian discrete framework (Discrete Element Method) for the particles. This method is referred to as the continuum discrete method (CDM) to clearly make a distinction between the ambiguity of using a Lagrangian or Eulerian reference for either continuum or discrete formulations. This freely available CDM code for gas–solids flows can accelerate the research in computational gas–solids flows and establish a baseline that can lead to better closures for the continuum modeling (or traditionally referred to as two fluid model) of gas–solids flows. In this paper, a series of verification cases is employed which tests the different aspects of the code in a systematic fashion by exploring specific physics in gas–solids flows before exercising the fully coupled solution on simple canonical problems. It is critical to have an extensively verified code as the physics is complex with highly-nonlinear coupling, and it is difficult to ascertain the accuracy of the results without rigorous verification. These series of verification tests set the stage not only for rigorous validation studies (performed in part II of this paper) but also serve as a procedure for testing any new developments that couple continuum and discrete formulations for gas–solids flows.

Garg, Rahul; Galvin, Janine; Li, Tingwen; Pannala, Sreekanth

2012-04-01

204

Open-source MFIX-DEM software for gas-solids flows: Part I verification studies  

SciTech Connect

With rapid advancements in computer hardware, it is now possible to perform large simulations of granular flows using the Discrete Element Method (DEM). As a result, solids are increasingly treated in a discrete Lagrangian fashion in the gas solids flow community. In this paper, the open-source MFIX-DEM software is described that can be used for simulating the gas solids flow using an Eulerian reference frame for the continuum fluid and a Lagrangian discrete framework (Discrete Element Method) for the particles. This method is referred to as the continuum discrete method (CDM) to clearly make a distinction between the ambiguity of using a Lagrangian or Eulerian reference for either continuum or discrete formulations. This freely available CDM code for gas solids flows can accelerate the research in computational gas solids flows and establish a baseline that can lead to better closures for the continuum modeling (or traditionally referred to as two fluid model) of gas solids flows. In this paper, a series of verification cases is employed which tests the different aspects of the code in a systematic fashion by exploring specific physics in gas solids flows before exercising the fully coupled solution on simple canonical problems. It is critical to have an extensively verified code as the physics is complex with highly-nonlinear coupling, and it is difficult to ascertain the accuracy of the results without rigorous verification. These series of verification tests set the stage not only for rigorous validation studies (performed in part II of this paper) but also serve as a procedure for testing any new developments that couple continuum and discrete formulations for gas solids flows.

Garg, Rahul [National Energy Technology Laboratory (NETL); Galvin, Janine [National Energy Technology Laboratory (NETL); Li, Tingwen [National Energy Technology Laboratory (NETL); Pannala, Sreekanth [ORNL

2012-01-01

205

Open-source MFIX-DEM software for gas-solids flows: Part 1 - Verification studies  

SciTech Connect

With rapid advancements in computer hardware, it is now possible to perform large simulations of granular flows using the Discrete Element Method (DEM). As a result, solids are increasingly treated in a discrete Lagrangian fashion in the gas–solids flow community. In this paper, the open-source MFIX-DEM software is described that can be used for simulating the gas–solids flow using an Eulerian reference frame for the continuum fluid and a Lagrangian discrete framework (Discrete Element Method) for the particles. This method is referred to as the continuum discrete method (CDM) to clearly make a distinction between the ambiguity of using a Lagrangian or Eulerian reference for either continuum or discrete formulations. This freely available CDM code for gas–solids flows can accelerate the research in computational gas–solids flows and establish a baseline that can lead to better closures for the continuum modeling (or traditionally referred to as two fluid model) of gas–solids flows. In this paper, a series of verification cases is employed which tests the different aspects of the code in a systematic fashion by exploring specific physics in gas–solids flows before exercising the fully coupled solution on simple canonical problems. It is critical to have an extensively verified code as the physics is complex with highly-nonlinear coupling, and it is difficult to ascertain the accuracy of the results without rigorous verification. These series of verification tests set the stage not only for rigorous validation studies (performed in part II of this paper) but also serve as a procedure for testing any new developments that couple continuum and discrete formulations for gas–solids flows.

Garg, Rahul; Galvin, Janine; Li, Tingwen; Pannala, Sreekanth

2012-04-01

206

An Adaptive Integration Model of Vector Polyline to DEM Data Based on Spherical Degeneration Quadtree Grids  

NASA Astrophysics Data System (ADS)

Traditional geometry-based approach can maintain the characteristics of vector data. However, complex interpolation calculations limit its applications in high resolution and multi-source spatial data integration at spherical scale in digital earth systems. To overcome this deficiency, an adaptive integration model of vector polyline and spherical DEM is presented. Firstly, Degenerate Quadtree Grid (DQG) which is one of the partition models for global discrete grids, is selected as a basic framework for the adaptive integration model. Secondly, a novel shift algorithm is put forward based on DQG proximity search. The main idea of shift algorithm is that the vector node in a DQG cell moves to the cell corner-point when the displayed area of the cell is smaller or equal to a pixel of screen in order to find a new vector polyline approximate to the original one, which avoids lots of interpolation calculations and achieves seamless integration. Detailed operation steps are elaborated and the complexity of algorithm is analyzed. Thirdly, a prototype system has been developed by using VC++ language and OpenGL 3D API. ASTER GDEM data and DCW roads data sets of Jiangxi province in China are selected to evaluate the performance. The result shows that time consumption of shift algorithm decreased about 76% than that of geometry-based approach. Analysis on the mean shift error from different dimensions has been implemented. In the end, the conclusions and future works in the integration of vector data and DEM based on discrete global grids are also given.

Zhao, X. S.; Wang, J. J.; Yuan, Z. Y.; Gao, Y.

2013-10-01

207

Quality of DEMs derived from Kite Aerial Photogrammety System: a case study of Dutch coastal environments.  

NASA Astrophysics Data System (ADS)

Coastal protection is one of the main challenges for the Netherlands, where a large proportion of anthropogenic activity is located below sea level (both residential and economic). The Dutch government is implementing an innovative method of coastal replenishment using natural waves and winds to relocate sand from one side to the other of the country. This requires close monitoring of the spatio-temporal evolution of beaches in order to correctly model the future direction and amount of sand movement. To do so -on the onshore beach- we tested a Kite-Aerial Photography System for monitoring the beach dynamics at Zandmotor (http://www.dezandmotor.nl/en-GB/). The equipment used for data collection were a commercial DSLR camera (Nikon D7000 with a 20mm lens), gyro-levelled rig, Sutton Flowform 16 kite and Leica GNSS Viva GS10, with GSM connection to the Dutch geodetic network. We flew using a 115 m line with an average inclination of 40 to 45°; this gave a camera vertical distance of ~80 m and pixel size of ~20 mm. The methodology follows that of Smith et al. (2009), and of Paron & Smith (2013), applied to a highly dynamic environment with low texture and small relief conditions. Here we present a comparison of the quality of the digital elevation model (DEM) generated from the same dataset using two different systems: Structure from Motion (SfM) using Agisoft Photoscan Pro and traditional photogrammetry using Leica Photograpmmetry Suite. In addition the outputs from the two data processing methods are presented, including both an image mosaic and DEM, and highlighting pros and cons of both methods. References Smith, M. J. et al. 2009. High spatial resolution data acquisition for the geosciences: kite aerial photography. ESPL, 34(1), 155-161. Paron, P., Smith, M.J. 2013. Kite aerial photogrammetry system for monitoring coastal change in the Netherlands. 8th IAG International Conference on Geomorphology, Paris, August.

Paron, Paolo; Smith, Mike J.; Anders, Niels; Meesuk, Vorawit

2014-05-01

208

830 IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, VOL. 6, NO. 4, OCTOBER 2009 DEM Error Retrieval by Analyzing Time Series  

E-print Network

-day European Remote Sensing 1 and 2 satellite (ERS-1/2) interferograms. Index Terms--Digital elevation model-resolution and high- accuracy topographic maps [1], [2] and to derive velocity fields [3]­[6]. The interferometric the topographic component from the interferograms. When the DEM is not precise enough, residual topographic fringe

Paris-Sud XI, Université de

209

De la culture itinrante sur brlis aux jachres enrichies productrices de charbon de bois, en Rep. Dem. Congo  

E-print Network

. Dem. Congo Peltier R, Bisiaux F, Dubiez E, Marien J-N, Muliele J-C, Proces P et Vermeulen C DE LA Régis PELTIER*, Franck BISIAUX**, Emilien DUBIEZ**, Jean-Noël MARIEN*, Jean-Claude MULIELE**, Pierre

Boyer, Edmond

210

Predicting discharge dynamics of wet cohesive particles from a rectangular hopper using the discrete element method (DEM)  

Microsoft Academic Search

Accurate prediction of the discharge rate from hoppers is important in many industrial processes involving the handling of granular materials. The present work investigates the parameters affecting the discharge rate of a wet cohesive system from a quasi-3-D, rectangular hopper using the discrete element method (DEM). The cohesion between the particles is described by a pendular liquid bridge force model

Anshu Anand; Jennifer S. Curtis; Carl R. Wassgren; Bruno C. Hancock; William R. Ketterhagen

2009-01-01

211

A generic procedure for automatically segmenting landforms into landform elements using DEMs, heuristic rules and fuzzy logic  

Microsoft Academic Search

A robust new approach for describing and segmenting landforms which is directly applicable to precision farming has been developed in Alberta. The model uses derivatives computed from DEMs and a fuzzy rule base to identify up to 15 morphologically defined landform facets. The procedure adds several measures of relative landform position to the previous classification of Pennock et al. (Geoderma

R. A. MacMillan; W. W. Pettapiece; S. C. Nolan; T. W. Goddard

2000-01-01

212

Exercise Lab: Where is the Himalaya eroding? Using GIS/DEM analysis to reconstruct surfaces, incision, and  

E-print Network

the Apatite FissionTrack data and some results from Pete Reiner's exercise. [Note: This is very useful 1 Exercise Lab: Where is the Himalaya eroding? Using GIS/DEM analysis to reconstruct surfaces for importing any types of data with coordinates (GPS data, field observations, Monzanite concentration, data

Bookhagen, Bodo

213

[Geben Sie ein Zitat aus dem Dokument The Red Orchestra a Documentary Film about a German Resistance network  

E-print Network

, Helmut Roloff who died in 2001. This highly acclaimed film incorporates a pioneering animation technique[Geben Sie ein Zitat aus dem Dokument The Red Orchestra ­ a Documentary Film about a German, and the youngest just 16. The Red Orchestra (film) For the first time, surviving members of the German resistance

Massachusetts at Amherst, University of

214

Comparison of SIFT and SURF based DEM extraction approaches on a GEOEYE-1 satellite stereo-pair  

NASA Astrophysics Data System (ADS)

A MATLAB module for Digital Elevation Model (DEM) extraction from Very High Resolution (VHR) satellite stereo-pair imagery is used to compare the efficiency of two well established feature detection and description algorithms. A procedure for parallel processing of cascading image tiles is used for handling the large datasets requirements of VHR satellite imagery. Scale-Invariant Feature Transform (SIFT) and Speeded Up Robust Features (SURF) algorithms are used to detect potentially tentative feature matches in the members of the stereo-pair. The resulting feature pairs are filtered using the RANdom SAmple Consensus (RANSAC) algorithm by using a variable distance threshold. Finally, tentative feature matches are converted to point cloud ground coordinates for DEM generation. A 0.5 m × 0.5 m Geoeye-1 stereo-pair acquired over an area of 25 km2 in the island of Crete, Greece is used as input for the module. The resulting 2 m × 2 m DEMs has superior detail over previously developed 2 m and 5 m DEMs that are used as reference, and yields a Root Mean Square Error (RMSE) of about 1 m compared to ground truth measurements. Results suggest that SURF's superior runtime performance outweighs the slightly better feature quality attained with SIFT.

Daliakopoulos, Ioannis; Tsanis, Ioannis

2014-05-01

215

Impact of DEM mesh size and soil map scale on SWAT runoff, sediment, and NO 3-N loads predictions  

NASA Astrophysics Data System (ADS)

The accuracy of agricultural nonpoint source pollution models depends to a great extent on how well model input spatial parameters describe the relevant characteristics of the watershed. It is assumed that reducing the precision of spatial input parameters affects the simulation results of runoff and sediment yield from the entire watershed. However, there may be no significant increase in the accuracy of models, as a result of more precise topographic or soil information, which increase the input data collection and preparation. The objective of this study was to determine the impact of the mesh size of the digital elevation model, DEM (from 20 to 500 m) and the soil map scale (1/25,000; 1/250,000 and; 1/500,000 scale) within the Soil and Water Analysis Tool (SWAT) to simulate runoff, sediment, and NO 3-N loads at the outlet of an agricultural watershed. Results of the Lower Walnut Creek (21.8 km 2, central Iowa) showed that an upper limit to DEM mesh size of 50 m is required to simulate watershed loads. Decreasing the mesh size beyond this threshold does not substantially affect the computed runoff flux but generated prediction errors for nitrogen and sediment yields. Whatever the DEM mesh size considered, a detailed soil map has to be considered to accurately estimate the loads. Finally, the impacts of DEM mesh size and soil map scale on the modeling results are discussed in respect of the relevant characteristics of the watershed and included in SWAT.

Chaplot, V.

2005-10-01

216

An dem Symposion ,,Alles hat seinen Preis Rechts fragen der Entgeltgestaltung" am 26. und 27. Juni 2014  

E-print Network

Anmeldung An dem Symposion ,,Alles hat seinen Preis ­ Rechts fragen der Entgeltgestaltung" am 26 SYMPOSION Alles hat seinen Preis ­ Rechtsfragen der Entgeltgestaltung ­ Stiftung Theorie und Praxis des, Universität Regensburg 14.15 Uhr Alles hat seinen Preis ­ Entgeltgestaltung aus Sicht der

Schubart, Christoph

217

Zur Verbreitung und Bestandssituation des Rebhuhns ( Perdix perdix L.) in Luxemburg, Lothringen, Rheinland-Pfalz und dem Saarland  

Microsoft Academic Search

Durch eine Befragung der Jägerschaft wurde eine flächendeckende Erfassung der Rebhuhnpopulationen im Großherzogtum Luxemburg und in Lothringen (Department Moselle, Frankreich) sowie in Rheinland-Pfalz und dem Saarland (BRD) durchgeführt. Es wurde festgestellt, daß das Rebhuhn im Untersuchungsraum nahezu flächendeckend verbreitet ist. Der Bestandstrend geht leicht nach oben. Die Populationsdichten sind jedoch, in Abhängigkeit von den naturräumlichen Gegebenheiten, sehr unterschiedlich. Ein positiver

V. Guthörl; P. Miiller

1991-01-01

218

Vegetation and slope effects on accuracy of a LiDAR-derived DEM in the sagebrush steppe  

Technology Transfer Automated Retrieval System (TEKTRAN)

This study analyzed the errors associated with vegetation cover type and slope on a LiDAR derived DEM in a semiarid environment in southwestern Idaho, USA. Reference data were collected over a range of vegetation cover types and slopes. Reference data were compared to ground raster values and Root...

219

BOREAS HYP-8 DEM Data Over The NSA-MSA and SSA-MSA in The AEAC Projection  

NASA Technical Reports Server (NTRS)

These data were derived from the original Digital Elevation Models (DEMs) produced by the Boreal Ecosystem-Atmosphere Study (BOREAS) Hydrology (HYD)-8 team. The original DEMs were in the Universal Transverse Mercator (UTM) projection, while this product is projected in the Albers Equal-Area Conic (AEAC) projection. The pixel size of the data is 100 meters, which is appropriate for the 1:50,000-scale contours from which the DEMs were made. The original data were compiled from information available in the 1970s and 1980s. This data set covers the two Modeling Sub-Areas (MSAs) that are contained within the Southern Study Area (SSA) and the Northern Study Area (NSA). The data are stored in binary, image format files. The DEM data over the NSA-MSA and SSA-MSA in the AEAC projection are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

Knapp, David E.; Hall, Forrest G. (Editor); Wang, Xue-Wen; Band, L. E.; Smith, David E. (Technical Monitor)

2000-01-01

220

Capturing Micro-topography of an Arctic Tundra Landscape through Digital Elevation Models (DEMs) Acquired from Various Remote Sensing Platforms  

NASA Astrophysics Data System (ADS)

The need to improve the spatial and temporal scaling and extrapolation of plot level measurements of ecosystem structure and function to the landscape level has been identified as a persistent research challenge in the arctic terrestrial sciences. Although there has been a range of advances in remote sensing capabilities on satellite, fixed wing, helicopter and unmanned aerial vehicle platforms over the past decade, these present costly, logistically challenging (especially in the Arctic), technically demanding solutions for applications in an arctic environment. Here, we present a relatively low cost alternative to these platforms that uses kite aerial photography (KAP). Specifically, we demonstrate how digital elevation models (DEMs) were derived from this system for a coastal arctic landscape near Barrow, Alaska. DEMs of this area acquired from other remote sensing platforms such as Terrestrial Laser Scanning (TLS), Airborne Laser Scanning, and satellite imagery were also used in this study to determine accuracy and validity of results. DEMs interpolated using the KAP system were comparable to DEMs derived from the other platforms. For remotely sensing acre to kilometer square areas of interest, KAP has proven to be a low cost solution from which derived products that interface ground and satellite platforms can be developed by users with access to low-tech solutions and a limited knowledge of remote sensing.

Vargas, S. A., Jr.; Tweedie, C. E.; Oberbauer, S. F.

2013-12-01

221

Classification and mapping of anthropogenic landforms on cultivated hillslopes using DEMs and soil thickness data --Example from the  

E-print Network

stability against gravity-induced movements (soil creep, landslide and debris flows) and controls rillClassification and mapping of anthropogenic landforms on cultivated hillslopes using DEMs and soil landforms of decametric width on cultivated hillslopes and their relations to soil thickness variability

Paris-Sud XI, Université de

222

The effect of DEM resolution on the computation of the factor of safety using an infinite slope model  

NASA Astrophysics Data System (ADS)

The quality of digital elevation models (DEMs) is essential for reliable landslide susceptibility assessments. In this paper, two DEMs derived from ASTER (ASTER GDEM v.2 with 30 m horizontal resolution) and TerraSAR-X (GeoElevation10 with 10 m horizontal resolution) data are compared to study the effects of resolution on the derived slope and wetness index parameters in the application of the infinite slope model for the computation of the factor of safety. Several slope stability scenarios representing different wetness conditions with 5, 10 and 100 mm d- 1 of steady-state recharge were calculated for the eastern flank of Mount Rinjani Volcano on Lombok Island, Indonesia. Each scenario was conducted by computing the static factor of safety with mean values of the bulk density, angle of internal friction, cohesion, and failure depth parameters, as well as for their normally distributed values by Monte Carlo simulation. All scenarios were applied to both DEMs. The scenarios were evaluated by calculating the success/prediction rate using the respective area under the curve (AUC) and an existing landslide inventory. Additionally, uncertainties in the estimated positions of landslides were taken into account. Depending on the particular scenario, the success rate of the GeoElevation10 model shows differences up to 3% compared to the ASTER GDEM model. This apparent improvement is mainly caused by the higher ground resolution in GeoElevation10. However, the success rate increases for the 10 mm d- 1 and decreases for the 100 mm d- 1 steady-state recharge conditions. Consequently, the more detailed flow direction in the GeoElevation10 DEM has the highest impact under conditions with lower water saturation. The slight improvement in the total model quality shows that the higher resolution of the DEM has a small impact on poorly parameterized models, in which the material properties are described by roughly estimated parameters. Therefore, the application of a high-resolution DEM to areas with a lack of data on the soil's physical properties is inefficient due to its low cost-benefit ratio. For quick analysis, the ASTER GDEM is of a suitable quality. To fully benefit from the high resolution of the DEMs, other parameters should be available in appropriate detail.

Fuchs, Michael; Torizin, Jewgenij; Kühn, Friedrich

2014-11-01

223

Characterization of active fault scarps from medium to high resolution DEM: case studies from Central and Southern Apennines (Italy)  

NASA Astrophysics Data System (ADS)

We identify geo-morphometric features of active fault scarps in Italy through a semiautomatic processing using GIS. Medium to high resolution DEM was used to characterize the geometry, structural, and erosive elements of two seismogenic normal faults in Central and Southern Apennines. The Pettino fault in L'Aquila area was detected using a 1 m pixel DEM derived from airborne LiDAR survey (Friuli Venezia Giulia Civil Protection). For the Castrovillari fault in northern Calabria region was used a 4 m pixel DEM (Regional Cartography Office of Regione Calabria). Scarp segments are region of planar discontinuities identified by selected values of DEM-derived Terrain Ruggedness Index (TRI) and Vector Ruggedness Measure (VRM). These planar discontinuities corresponds to landscape features such as, river terraces, roads scarps, and other natural or human features. The discrimination between these features have been accomplished overlaying extracted features on aerial photograph, geological and geomorphologic maps and in situ survey. After that, we perform the quantitative and statistical analysis of these areas identified as "fault scarps". The identification of elements relative to the scarps (e.g. base, crest, slope) is then obtained to derive the estimate of parameters describing the fault: altitude, height of the scarp, length, slope and aspect, Terrain Ruggedness Index (TRI) and Vector Ruggedness Measure (VRM). The spatial distribution of the extracted values was obtained through their statistical analysis. We analyze scarp parameters variations along the whole scarp extent, such as strike value from aspect variations, slope and profile curvature differences as indicators of tectonic and/or erosion activity. The combined analysis of the DEM-derived parameters allows us to (a) define aspects of three-dimensional scarp geometry, (b) decipher its geomorphological significance, and (c) estimate the long-term slip rate.

Brunori, C.; Cinti, F. R.; Ventura, G.

2013-12-01

224

Constructing a Comprehensive Tool for Deriving Drainage Network using Semi-Open Source Tools and Comparision on Different DEM Data Sources  

NASA Astrophysics Data System (ADS)

Digital elevation model (DEM) provides elevation information in raster format for an area which help in analysis as these phenomena are gravity depended. Hydrological study requires creation of drainage network map. DEM is the primary input for this process. Generally 6 or more processes are required to be completed to get the drainage network. These are available in form of hydrology tools in the ArcGIS software. These processes are manual and time consuming which increases the chances of human error. An automated process is constructed in this paper which aims to create a tool that can handle multiple files in an intelligent manner. The input DEM plays a significant role in hydrological studies. This study attempts to do a comparative study to analyse the variation in the drainage network and the intermediate products with the change in the input DEM. A tool is created using ArcPy site package in Python programming language to integrate all required hydrology tools. The script is then used to create a tool in ArcGIS 10 which takes location as an input parameter and perform the process on all the DEM files inside the directory. The tool creates separate directory for every DEM file and thus reduces the chances of file mismanagement. The proposed tool is tested on two different datasets namely ASTER GDEM and Cartosat DEM. The tool runs efficiently on both the datasets and thus provides results to compare the drainage pattern produced by these different data sources.

Gupta, P. K.; Yadav, P.

2014-11-01

225

The accuracy of photo-based structure-from-motion DEMs  

NASA Astrophysics Data System (ADS)

Data for detailed digital elevation models (DEMs) are usually collected by expensive laser-based techniques, or by photogrammetric methods that require expertise and specialist software. However, recent advances in computer vision research now permit 3D models to be automatically derived from unordered collections of photographs, offering the potential for significantly cheaper and quicker DEM production. Here, we assess the accuracy of this approach for geomorphological applications using examples from a coastal cliff and a volcanic edifice. The reconstruction process is based on a combination of structure-from-motion and multi-view stereo algorithms (SfM-MVS). Using multiple photographs of a scene taken from different positions with a consumer-grade camera, dense point clouds (millions of points) can be derived. Processing is carried out by automated 'reconstruction pipeline' software downloadable from the internet, e.g. http://blog.neonascent.net/archives/bundler-photogrammetry-package/. Unlike traditional photogrammetric approaches, the initial reconstruction process does not require the identification of any control points or initial camera calibration and is carried out with little or no operator intervention. However, such reconstructions are initally un-scaled and un-oriented so additional software (http://www.lancs.ac.uk/staff/jamesm/software/sfm_georef.htm) has been developed to permit georeferencing. Although this step requires the presence of some control points or features within the scene, it does not have the relatively strict image acquisition and control requirements of traditional photogrammetry. For accuracy, and to allow error analysis, georeferencing observations are made within the image set, rather than requiring feature matching within the point cloud. In our coastal example, 133 photos taken with a Canon EOS 450D and 28 mm prime lens, from viewing distances of ~20 m, were used to reconstruct a ~60 m long section of eroding cliff. The resulting surface model was compared with data collected by a Riegl LMS-Z210ii terrestrial laser scanner. Differences between the surfaces were dominated by the varying effects of occlusions on the techniques, and systematic distortion of the SfM-MVS model along the length of the cliff could not be resolved over the ±15 mm precision of the TLS data. For a larger-scale example, a ~1.6 km wide region over the summit of Piton de la Fournaise volcano was reconstructed using 133 photos taken with a Canon EOS D60 and 20 mm prime lens, from a microlight aircraft (with a representative viewing distance of 1.0 km). In this case, the resulting DEM showed an RMS error of 1.0 m when compared with the results from traditional photogrammetry and some areas of systematic error were evident. Such errors were minimised by reprocessing the SfM-MVS results with a more sophisticated camera model than is integrated into the reconstruction pipeline. In combination, the results indicate that, with a good, convergent image set, SfM-MVS can be anticipated to deliver relative precisions of 1:1000 or better, for geomorphological applications. However, under certain conditions, the restricted camera model used can result in detectable error. We highlight the requirement for new network design tools that will help optimise image collection, facilitate error visualisation and allow a user to determine whether their image network is fit for purpose.

James, M. R.; Robson, S.

2012-04-01

226

Shuttle Topography Radar Mission DEM, ASTER Images and Aerial Photography in Evaluation of Mountain Glacier Area and Volume Changes  

NASA Astrophysics Data System (ADS)

The glacier monitoring on a regional scale have been done traditionally by means of optical space images resulting mainly in observing of changes of area, length and other 2-D information. A lack of texture on the snow fields, steep walls with deep shadows and often cloudiness in high mountains significantly reduce quality and availability of photogrammetrically derived Digital Elevation Models (DEM). Laser altimetry and repeat-pass InSAR DEMs show large potential for glacier volume changes measurements but still have very limited spatial coverage. Recently released 3-arcsecond DEM by NASA-JPL resulted from STRM flown in February 2000 provide unique opportunity for regional-scale glacier change assessment. The method of glacial area and glacier volume changes has been developed over the Akshiirak ice-fields in the Tien Shan Mountains, Central Asia using aerial photography of 1977, topographic maps and RS data of 2000/2003. The datum transformation from WGS-84 used in STRM data to Pulkovo 1942 (Russian) coordinate system was accomplished by 7-parameter Helmert transformation with accuracy at least one order higher than STRM horizontal accuracy (20 m). For vertical validation we compared STRM DEM with DEM constructed from 10 and 5 m additional contour lines digitized from 1:25000 topographic maps on non-glacial relatively flat areas. Though well consistent with 16 m (90%) absolute vertical accuracy, relative accuracy requirement of 6 m (90%) can be easily met only after removing systematic wavy bias in along-track direction. The Akshiirak ice-fields have more than 83% area inclination below 30° . These factors reduce influence of slope-related STRM vertical error to final glacier volume change calculations. Glacier boundaries were manually digitized from an ASTER L1A image acquired on August 18, 2003 that was orthorectified in Orthobase digital photogrammetric package with 9.5 m RMSE of 28 GCPs. For delineating of glaciers in problem areas (debris-covered termini, shadows) we used thermal bands and true hardware-enabled stereo viewing with nadir 3N and backward-looking 3B bands. Accuracy of digitized 2003 glacier boundaries were checked against GPS measurements of 7 glacier termini made in 2002. For surface elevation comparison a second DEM was generated from 10 m contour lines for all glaciers (424 km2) using 16 topographic maps of 1:25000 scale created from 1977 aerial photography. The map vertical accuracy is 1/3 of contour interval. Glacier boundaries of 1977 were directly delineated from stereo models. It is revealed that from 1977 till 2003 Akshiirak glaciers have lost 10 km3 of ice volume and 35 km2 of area.

Surazakov, A. B.; Aizen, V. B.; Kuzmichenok, V. A.

2004-12-01

227

The Multi-Instrument, Comprehensive Differential Emission Measure (DEM) of the Solar Corona During Flares and Quiescent Periods  

NASA Astrophysics Data System (ADS)

Thermal plasma in the solar corona, while often modeled as isothermal for ease of analysis, is in fact decidedly multi-thermal, ranging from ~1-2 MK in the quiescent corona to ~30-50 MK in intensely flaring loops. It has proven difficult to obtain a well-constrained differential emission measure (DEM) from a single instrument, as the wavelength ranges of individual instruments, even those with broadband coverage, provide sensitivity to only a limited range of plasma temperatures. Recently, we developed a new technique using combined extreme ultraviolet (EUV) and soft and hard X-ray (SXR, HXR) data from the EUV Variability Experiment (EVE) onboard the Solar Dynamics Observatory (SDO) and the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), respectively, to obtain a self-consistent DEM that is strongly constrained across the full range of coronal plasma temperatures (<2 to >50 MK). An accurate, precise determination of the plasma temperature distribution enables not only studies of plasma heating and thermal plasma evolution, but can also provide strong constraints on the non-thermal accelerated electron population, including the low-energy cutoff which is typically determined only as a loose upper limit.We present EVE+RHESSI DEM results from selected intense (X-class) flares from solar cycle 24, including determining the non-thermal low-energy cutoff and examining how this evolves with the temperature distribution. We also apply this technique to combine EUV data from EVE with SXR data from the GOES X-ray Sensor (XRS) and the X123, a new SXR spectrometer flown on two recent SDO/EVE calibration sounding rockets, to examine the DEM during quiescent (non-flaring) times with varying activity levels; the X-ray data provide crucial constraints on the high-temperate extent of the DEM and any potential non-thermal emission. We compare these results with those from a parallel technique to derive DEMs from imaging data from the Atmospheric Imaging Assembly (AIA) onboard SDO, and we discuss the implications for plasma heating, both during flares and in the quiescent corona. This research is supported by NASA contracts NAS5-98033 and NAS5-02140, and NASA Heliophysics Guest Investigator Grant NNX12AH48G.

Caspi, Amir; McTiernan, James; Warren, Harry; Woods, Thomas N.

2014-06-01

228

Production of Optimized DEM Using IDW Interpolation Method (Case Study; Jam and Riz Basin-Assaloyeh)  

NASA Astrophysics Data System (ADS)

In this research, preparing the optimized Digital Elevation Model (DEM)of Jam and Riz basin was studied by use of Inverse Distance Weighting (IDW) and utilization of GIS technique. Performing of IDW method depends on several factors including cell size, number of neighbor`s points, point searching radius and optimized power. On this basis, two Geostatistical methods were used for determination of points searching radius of standard ellipse and standard deviation ellipse. Considering the fixed cell size in network with value of 3 which represents weighting degree of points and with determining the rotation angle and measure of axis of standard deviation ellipse and calculation of optimized radius in standard ellipse by use of statistical method, then optimized power was automatically derived in ArcGIS 9.2 environment. In this method the number of neighbor's points was selected with four repetition points of 3, 5, 7 and 15. However, 8 digital elevation models were gained after the mentioned processes. Finally, digital elevation models of 1 to 8 were compared with control points using compare means test in SPSS11.5 statistical software which shown the IDW-3 with the best conditions recommended as the optimized model. Although the results are showing a similar forms but from them IDW3 model has the lowest mean standard error of 0.26842 which is used seven neighbor points.

Soleimani, K.; Modallaldoust, S.

229

Classification of topography using DEM data and its correlation with the geology of Greece  

NASA Astrophysics Data System (ADS)

Continuous topography from Digital Elevation Model (DEM) data is frequently segmented into terrain classes based on local morphological characteristics of terrain elevation, e.g., local slope gradient and convexity. The resulting classes are often used as proxies for the average shear wave velocity up to 30 m, and the determination of ground types as required by the Eurocode (EC8) for computing elastic design spectra. In this work, we investigate the links between terrain related variables, particularly slope gradient, extracted for the area of Greece from the Shuttle Radar Topography Mission (SRTM) 30 arc second global topographic data available from the United States Geological Survey (USGS), with: (a) the global terrain classification product of Iwahashi and Pike (2007) in which 16 terrain types are identified for the same spatial resolution, and (b) information on geological units extracted at the same resolution from the geological map of Greece at a scale of 1/500000 as published from the Institute of Geology and Mineral Exploration (IGME). An interpretation of these links is presented within the context of understanding the reliability of using geology, slope and terrain classes for site characterizations of earthquake risk in a high seismicity area like Greece. Our results indicate that slope is a somewhat biased proxy for solid rocks, whereas in Alluvial deposits the distance to and type of the nearest geological formation appears to provide qualitative information on the size of the sedimentary deposit.

Zargli, Eleni; Liodakis, Stelios; Kyriakidis, Phaedon; Savvaidis, Alexandros

2013-08-01

230

CFD-DEM study of effect of bed thickness for bubbling fluidized beds  

SciTech Connect

The effect of bed thickness in rectangular fluidized beds is investigated through the CFD–DEM simulations of small-scale systems. Numerical results are compared for bubbling fluidized beds of various bed thicknesses with respect to particle packing, bed expansion, bubble behavior, solids velocities, and particle kinetic energy. Good two-dimensional (2D) flow behavior is observed in the bed having a thickness of up to 20 particle diameters. However, a strong three-dimensional (3D) flow behavior is observed in beds with a thickness of 40 particle diameters, indicating the transition from 2D flow to 3D flow within the range of 20–40 particle diameters. Comparison of velocity profiles near the walls and at the center of the bed shows significant impact of the front and back walls on the flow hydrodynamics of pseudo-2D fluidized beds. Hence, for quantitative comparison with experiments in pseudo-2D columns, the effect of walls has to be accounted for in numerical simulations.

Tingwen, Li; Gopalakrishnan, Pradeep; Garg, Rahul; Shahnam, Mehrdad

2011-10-01

231

Hydrological characterization of volcanic island by DEM generation using ASAR (ENVISAT): Galapagos  

NASA Astrophysics Data System (ADS)

Low topographic oceanic islands often suffer from scarcity of freshwater resources and are poorly characterized due to their complex internal structure and challenging access. Remote sensing has proved to be an effective tool to generate valuable data for hydrological analysis. However, these are usually tested over areas with existing validation databases and not always where the need is greatest. Here we address the need for topographical data for hydrological understanding of Santa Cruz Island (Galapagos Archipelago) where no high resolution, no high accuracy topographical data exists. 97 percent of Galapagos territory consists of inaccessible National Park land which makes the use of indirect methods indispensable. We used new ASAR data (ENVISAT) for Digital Elevation Model generation, in order to extract drainage network, watersheds, and flow characteristics from a morpho-structural analysis. Results show the high potential of this data for both interferometric and radargrammetric generation methods. If interferometry suffered from low coherence over highly vegetated areas, it showed high precision over the rest of the island. Radargrammetry gave consistent results over the entire island, and detail was enhanced by integrating the SRTM as an external DEM. Validation of the extracted river networks and watersheds was carried out using ground-based field observations, comparison to drainage network extracted from aerial photographs and to high resolution (1 m) satellite imagery. For the first time watershed characteristics and flow paths are made available for an island of the Galapagos archipelago. Drainage networks and underground percolation are strongly influenced by fractures.

D'Ozouville, N.; Violette, S.; Benveniste, J.; Wegmuller, U.; Deffontaines, B.; de Marsily, G.

2007-12-01

232

The TerraSAR-X/TanDEM-X Formation Acquisition-from Planning to Realization  

NASA Astrophysics Data System (ADS)

On June 21, 2010 the TanDEM-X satellite (TDX) was injected into orbit at 15,700 km distance from its twin satellite TerraSAR-X (TSX), which has been in orbit since 2007. Already one month later TDX acquired a formation with TSX in order to build up the first single-pass radar interferometer in space. Within three years of close formation flying with flexible baselines ranging from 150 m to a few kilometers the twin satellites will collect interferometric radar measurements for the generation of a global digital elevation model with unprecedented accuracy. This paper elaborates on the TDX pre-launch analysis performed in the fields of collision assessment during orbit injection and target formation acquisition. To avoid a critical close approach shortly after TDX separation, the risk of collision between the already flying TSX satellite and the newly injected elements (DNEPR upper-stage, gas dynamic shield, and TDX satellite) had to be carefully analyzed. Further, the paper discusses a fuel-saving formation acquisition strategy, for which the maneuver budget is analyzed as a function of launch day and launch injection accuracy. Finally, flight results are presented to illustrate the successful formation acquisition realized in July 2010 and the formation reconfiguration process from the 20 km wide formation into the 300-400 m close formation performed in October 2010. This reconfiguration marked the start of the bi-static TDX/TSX instrument operation.

Kahle, Ralph; Schlepp, Benjamin; Meissner, Florian; Kirschner, Michael; Kiehling, Reinhard

2012-09-01

233

Macromolecular Structure Modeling from 3DEM Using VolRover 2.01  

PubMed Central

We report several tools for 3DEM structure identification and model-based refinement developed by our research group and implemented in our in-house software package, VolRover. For viral density maps with icosahedral symmetry, we segment the capsid, polymeric and monomeric subunits using segmentation techniques based on symmetry detection and fast marching. For large biomolecules without symmetry information, we use a multi-seeded fast-marching method to segment meaningful substructures. In either case, we subject the resulting segmented subunit to secondary structure detection when the EM resolution is sufficiently high, and rigid-body fitting when the corresponding crystal structure is available. Secondary structure elements are identified by our volume- and boundary-based skeletonization methods as well as a new method, currently in development, based on solving the grassfire flow equation. For rigid-body fitting, we use a translational fast Fourier based scheme. We apply our segmentation, secondary structure elements identification, and rigid-body fitting techniques to the PSB 2011 cryo-EM modeling challenge data, and compare our results to those submitted from other research groups. The comparisons show that our software is capable of segmenting relatively accurate subunits from a viral or protein assembly, and that the high segmentation quality leads in turn to high-quality results of secondary structure elements identification and rigid-body fitting. PMID:22696407

Zhang, Qin; Bettadapura, Radhakrishna

2012-01-01

234

DEM simulation of particle mixing for optimizing the overcoating drum in HTR fuel fabrication  

NASA Astrophysics Data System (ADS)

The rotating drum was used for overcoating coated fuel particles in HTR fuel fabrication process. All the coated particles should be adhered to equal amount of graphite powder, which means that the particle should be mixed quickly in both radial and axial directions. This paper investigated the particle flow dynamics and mixing behavior in different regimes using the discrete element method (DEM). By varying the rotation speed, different flow regimes such as slumping, rolling, cascading, cataracting, centrifuging were produced. The mixing entropy based on radial and axial grid was introduced to describe the radial and axial mixing behaviors. From simulation results, it was found that the radial mixing can be achieved in the cascading regime more quickly than the slumping, rolling and centrifuging regimes, but the traditional rotating drum without internal components can not achieve the requirements of axial mixing and should be improved. Three different structures of internal components are proposed and simulated. The new V-shaped deflectors were found to achieve a quick axial mixing behavior and uniform axial distribution in the rotating drum based on simulation results. At last, the superiority was validated by experimental results, and the new V-shaped deflectors were used in the industrial production of the overcoating coated fuel particles in HTR fuel fabrication process.

Liu, Malin; Lu, Zhengming; Liu, Bing; Shao, Youlin

2013-06-01

235

Predicting anthropogenic streambed shifts in Beckley, West Virginia, modeled over 15 years using LANDSAT TM and DEMS  

NASA Astrophysics Data System (ADS)

Anthropogenic change of streambeds in the Beckley, West Virginia watershed region was modeled using Landsat 5 TM satellite data from 1988 and 2003, and Digital Elevation Model (DEM) data for 1969 and 2005. Comparing the 15 year land cover changes and the 36 year elevation shifts, and using a modified Universal Soil Loss Equation (USLE), in ESRI ArcMap and ERDAS Imagine, a streambed shift model was created. The model predicted land cover and elevation changes for 2018, using inputs from geospatial differencing of 2003 and 1988 land cover as well as 2003 and 1969 DEM data. Further analysis using hydrodynamic differential equations provided in depth information on stream clogging over the 15 year study period.

Reinhardt, Andrew D.

236

3D Shape Characterization and Image-Based DEM Simulation of the Lunar Soil Simulant FJS-1  

Microsoft Academic Search

This paper describes a procedure used to characterize the three-dimensional 3D grain shape of lunar soil and undertake simulations of lunar soil by image-based discrete element method DEM. Given that detailed 3D grain-shape information is unavailable for real lunar soil, a simulant material, FJS-1, is used in this study. We use the high-resolution micro X-ray CT system at SPring-8, a

Takashi Matsushima; Jun Katagiri; Kentaro Uesugi; Akira Tsuchiyama; Tsukaka Nakano

2009-01-01

237

Studien auf dem Gebiete der Holzschutzchemie—7. Mitteilung: Untersuchung frühgeschichtlicher Hölzer und deren Bedeutung für den Holzschutz  

Microsoft Academic Search

Zusammenfassung  Die Isolierung und Bestimmung der für die Dauerhaftigkeit frühgeschichtlicher Hölzer verantwortlichen natülichen Schutzstoffe\\u000a kann dem Chemiker nützliche Hinweise für die Synthese organischer Holzschutzmittel geben. Aus diesem Grunde wurden gut erhaltene\\u000a ägyptische Sarghölzer (Holza etwa 4500 Jahre alt, Holzb etwa 3000 Jahre alt) sowie Hölzer aus Tempeln der alten Maya-Metropole\\u000a Tikal (Guatemala) und Chichen-Itza (Alter etwa 1150 bwz. 600 bis 1000

W. Sandermann; H. H. Dietrichs; H. Gottwald

1958-01-01

238

First Results on Accuracy Analysis for DEM and Orthoimages Derived from SPOT HRS Stereo Data over Bavaria  

Microsoft Academic Search

ABSTRACT ISPRS and CNES announced,the HRS (High Resolution Stereo) Assessment Program during the ISPRS Commission,I Symposium,in Denver in November ,2002. 9 test areas throughout the world have been selected for this program. One of the ,test sites is located in Bavaria, Germany, for which the PI comes from DLR. The goal is to derive a DEM from the along-track stereo

Peter Reinartz; Manfred Lehner; Rupert Müller; Matthias Rentsch; Manfred Schroeder

239

GIS-based debris flow source and runout susceptibility assessment from DEM data - a case study in NW Nicaragua  

NASA Astrophysics Data System (ADS)

In October 1998, Hurricane Mitch triggered numerous landslides (mainly debris flows) in Honduras and Nicaragua, resulting in a high death toll and in considerable damage to property. The potential application of relatively simple and affordable spatial prediction models for landslide hazard mapping in developing countries was studied. Our attention was focused on a region in NW Nicaragua, one of the most severely hit places during the Mitch event. A landslide map was obtained at 1:10 000 scale in a Geographic Information System (GIS) environment from the interpretation of aerial photographs and detailed field work. In this map the terrain failure zones were distinguished from the areas within the reach of the mobilized materials. A Digital Elevation Model (DEM) with 20 m×20 m of pixel size was also employed in the study area. A comparative analysis of the terrain failures caused by Hurricane Mitch and a selection of 4 terrain factors extracted from the DEM which, contributed to the terrain instability, was carried out. Land propensity to failure was determined with the aid of a bivariate analysis and GIS tools in a terrain failure susceptibility map. In order to estimate the areas that could be affected by the path or deposition of the mobilized materials, we considered the fact that under intense rainfall events debris flows tend to travel long distances following the maximum slope and merging with the drainage network. Using the TauDEM extension for ArcGIS software we generated automatically flow lines following the maximum slope in the DEM starting from the areas prone to failure in the terrain failure susceptibility map. The areas crossed by the flow lines from each terrain failure susceptibility class correspond to the runout susceptibility classes represented in a runout susceptibility map. The study of terrain failure and runout susceptibility enabled us to obtain a spatial prediction for landslides, which could contribute to landslide risk mitigation.

Guinau, M.; Vilajosana, I.; Vilaplana, J. M.

2007-11-01

240

Quantifying Ice-sheet/Ice-shelf Dynamics and Variability with Meter-scale DEM and Velocity Timeseries  

NASA Astrophysics Data System (ADS)

Both the Antarctic and Greenland ice sheets are losing mass at an increasing rate, although loss due to accelerating flow and dynamic thinning remains poorly understood. We are using complementary data from repeat satellite and airborne observations to investigate the relationship between ice-sheet/ice-shelf dynamics and geometry on seasonal to interannual timescales. High-resolution along-track stereo imagery from commercial satellite vendors DigitalGlobe and GeoEye provides unprecedented spatial (~0.5 m/px with ~17 km swath width) and temporal (weekly/monthly) resolution for these efforts. We have developed an automated pipeline using open-source software to produce orthoimage, DEM, and surface velocity products from DigitalGlobe imagery. High-contrast surface texture (e.g. sastrugi, crevasses) visible at sub-meter resolution provides near-perfect image correlation (~99% success rate) during DEM and velocity map derivation. Elevation data from IceBridge ATM/LVIS, ICESat GLAS, and GPS campaigns are used to correct DEMs and perform accuracy assessment. Preliminary tests over exposed bedrock provide relative vertical accuracy estimates of <1-2 m for Worldview-1/2 DEMs. Velocity data from TerraSAR-X and GPS campaigns provide validation for surface velocity products, with horizontal error estimates of <10 m. Velocity and elevation change products with 2-4 m/px spatial resolution allow for unprecedented 3D dynamic characterization of sub-km flow transition zones (e.g. grounding lines, shear margins), capturing both local and regional variations due to melting and dynamic thinning. We present timeseries for West Greenland (Jakobshavn front - 20 observations, Jakobshavn south catchment - 10) and West Antarctica (Pine Island and Thwaites - 5 each) from 2009-2012. These observations complement ongoing efforts to measure and model outlet glacier dynamics, with implications for future ice-sheet mass balance estimates.

Shean, D. E.; Joughin, I. R.; Smith, B. E.; Moratto, Z. M.; Porter, C.; Morin, P. J.

2012-12-01

241

Direct micromechanics derivation and DEM confirmation of the elastic moduli of isotropic particulate materials: Part I No particle rotation  

NASA Astrophysics Data System (ADS)

We derive the macroscopic elastic moduli of a statistically isotropic particulate aggregate material via the homogenization methods of Voigt (1928) (kinematic hypothesis), Reuss (1929) (static hypothesis), and Hershey (1954) and Kröner (1958) (self-consistent hypothesis), originally developed to treat crystalline materials, from the directionally averaged elastic moduli of three regular cubic packings of uniform spheres. We determine analytical expressions for these macroscopic elastic moduli in terms of the (linearized) elastic inter-particle contact stiffnesses on the microscale under the three homogenization assumptions for the three cubic packings (simple, body-centered, and face-centered), assuming no particle rotation. To test these results and those in the literature, we perform numerical simulations using the discrete element method (DEM) to measure the overall elastic moduli of large samples of randomly packed uniform spheres with constant normal and tangential contact stiffnesses (linear spring model). The beauty of DEM is that simulations can be run with particle rotation either prohibited or unrestrained. In this first part of our two-part series of papers, we perform DEM simulations with particle rotation prohibited, and we compare these results with our theoretical results that assumed no particle rotation. We show that the self-consistent homogenization assumption applied to the locally body-centered cubic (BCC) packing most accurately predicts the measured values of the overall elastic moduli obtained from the DEM simulations, in particular Poisson's ratio. Our new analytical self-consistent results lead to significantly better predictions of Poisson's ratio than all prior published theoretical results. Moreover, our results are based on a direct micromechanics analysis of specific geometrical packings of uniform spheres, in contrast to all prior theoretical analyses, which were based on difficult-to-verify hypotheses involving overall inter-particle contact distributions. We continue the analysis begun in this first part for the case of unrestrained particle rotation in Part II, Fleischmann et al. (2013).

Fleischmann, J. A.; Drugan, W. J.; Plesha, M. E.

2013-07-01

242

Estimating the rate and elevation dependence of net accretion in a freshwater tidal marsh using DEM-registered surveys  

NASA Astrophysics Data System (ADS)

Tidal freshwater marshes contribute to estuary health by filtering excess sediment and nutrients delivered from the watershed, but their extent and persistence is threatened by rising sea level. To maintain a semi-emergent position, the marsh surface must gain elevation by accreting mineral and/or organic material at a rate comparable to sea level rise. Historic records of sea level rise (SLR) are available from tide gages, but records of historic elevation change at the necessary precision are rare. Additionally, sedimentation, compaction, erosion, and the resultant net elevation gain are spatially heterogeneous across a marsh, varying with elevation, among other factors. We solve this issue at our study site by taking advantage of a 1992 total station survey of the marsh and RTK GPS surveys from 2005 and 2012, and registering them all against an airborne LiDAR derived DEM. Thus, although no points are directly reoccupied, survey vs. DEM trends can be found for each survey, and an average rate of elevation change can be calculated as a function of DEM elevation. We found rates of net elevation gain ranging spatially from 3-5 mm/yr between the years 1992-2012, similar to the historic rate of SLR at a nearby Washington, DC tide gage of 4 mm/yr over the past 28 years. Net elevation change varied as DEM elevation increased, with several local minima and maxima potentially related to variations and transitions in vegetation community. Assuming IPCC predicted sea level rise and a fixed relationship between elevation and net accretion, we then forecast marsh elevation relative to sea level and associated vegetative community changes through the 21st century using an inundation model that considers net accretion and a constant relationship between vegetation community type and elevation.

Cadol, D. D.; Elmore, A. J.; Engelhardt, K.; Sanders, G.

2012-12-01

243

Precise Determination of the Baseline Between the TerraSAR-X and TanDEM-X Satellites  

NASA Astrophysics Data System (ADS)

TerraSAR-X, launched on June 15, 2007, and TanDEM-X, to be launched in September 2009, both carry the Tracking, Occultation and Ranging (TOR) category A payload instrument package. The TOR consists of a high-precision dual-frequency GPS receiver, called Integrated GPS Occultation Receiver (IGOR), for precise orbit determination and atmospheric sounding and a Laser retro-reflector (LRR) serving as target for the global Satellite Laser Ranging (SLR) ground station network. The TOR is supplied by the GeoForschungsZentrum Potsdam (GFZ) Germany, and the Center for Space Research (CSR), Austin, Texas. The objective of the German/US collaboration is twofold: provision of atmospheric profiles for use in numerical weather predictions and climate studies from the occultation data and precision SAR data processing based on precise orbits and atmospheric products. For the scientific objectives of the TanDEM- X mission, i.e., bi-static SAR together with TerraSAR-X, the dual-frequency GPS receiver is of vital importance for the millimeter level determination of the baseline or distance between the two spacecrafts. The paper discusses the feasibility of generating millimeter baselines by the example of GRACE, where for validation the distance between the two GRACE satellites is directly available from the micrometer-level intersatellite link measurements. The distance of the GRACE satellites is some 200 km, the distance of the TerraSAR-X/TanDEM-X formation will be some 200 meters. Therefore the proposed approach is then subject to a simulation of the foreseen TerraSAR-X/TanDEM-X formation. The effect of varying space environmental conditions, of possible phase center variations, multi path, and of varying center of mass of the spacecrafts are evaluated and discussed.

Koenig, Rolf; Rothacher, Markus; Michalak, Grzegorz; Moon, Yongjin

244

An Example of Realistic Modelling of Rock Dynamics Problems: FEM/DEM Simulation of Dynamic Brazilian Test on Barre Granite  

NASA Astrophysics Data System (ADS)

The scope of this study is to numerically simulate the behaviour of Brazilian disc specimens as observed in laboratory during dynamic, high-strain rate, indirect tensile tests using an innovative combined finite-discrete element method (FEM/DEM) research code. Laboratory experiments using a split Hopkinson pressure bar (SHPB) apparatus were conducted by the authors and the measured indirect tensile strength values were used to verify the FEM/DEM models. In the models the applied boundary conditions, related to the loading rate of the specimen, were matched with the experimental observations. The results of the numerical simulations, including tensile strength and failure time, are in agreement with the laboratory findings. The main failure mechanisms, i.e. tensile splitting along loading axis and shear failure close to loading platens are captured by the numerical model. A linear relationship between tensile strength and loading rate is found for the range of dynamic strain rates tested and simulated. The simulation results are in good agreement with laboratory observations and demonstrate the potential for using FEM/DEM to realistically model dynamic response of rocks.

Mahabadi, O. K.; Cottrell, B. E.; Grasselli, G.

2010-11-01

245

Das gemeinsame Klangideal von Belcanto und altitalienischen Geigen  

Microsoft Academic Search

Die erste Frage, mit der wir uns unter dieser Themenstellung zu beschäftigen haben, ist die nach der Begründung eines Klangideals, das dem Gesang und dem Streichinstrumentenklang gemeinsam ist. Wieso ist es überhaupt berechtigt, von einem Klangideal auszugehen? Ein Vergleich zwischen den klanglichen Charakteristika von Gesangstil und Streicherklang in den unterschiedlichsten Kulturen ergibt zweierlei: Zum einen findet man zwischen Kulturen große

Georg Heike

246

Studium der Stationären und Laufenden Schichtung in der Entladung in Neon Mit Hilfe eines Lokalen Hochfrequenzfeldes  

Microsoft Academic Search

Zusammenfassung Es wurde ein Verfahren zur Erregung von stationären Schichten, der Schichtungswelle und der laufenden Schichten in der Gleichstromentladung ausgearbeitet, das auf der Einwirkung eines Hochfrequenzfeldes auf einen kurzen Abschnitt der positiven Säule beruht. Dieses Verfahren wurde zum Studium aller drei angeführten Schichtungsarten in Neon benützt, insbesondere jedoch zum Studium des Zusammenhanges zwischen den laufenden und den stationären Schichten.

M. Šícha; V. Veselý; J. Studnicka; J. Prostejovský; M. Novák

1962-01-01

247

Release of a 10-m-resolution DEM for the whole Italian territory: a new, freely available resource for research purposes  

NASA Astrophysics Data System (ADS)

Digital elevation models (DEMs) are fundamental in any kind of environmental or morphological study. DEMs are obtained from a variety of sources and generated in several ways. Nowadays, a few global-coverage elevation datasets are available for free (e.g., SRTM, http://www.jpl.nasa.gov/srtm; ASTER, http://asterweb.jpl.nasa.gov/). When the matrix of a DEM is used also for computational purposes, the choice of the elevation dataset which better suits the target of the study is crucial. Recently, the increasing use of DEM-based numerical simulation tools (e.g. for gravity driven mass flows), would largely benefit from the use of a higher resolution/higher accuracy topography than those available at planetary scale. Similar elevation datasets are neither easily nor freely available for all countries worldwide. Here we introduce a new web resource which made available for free (for research purposes only) a 10 m-resolution DEM for the whole Italian territory. The creation of this elevation dataset was presented by Tarquini et al. (2007). This DEM was obtained in triangular irregular network (TIN) format starting from heterogeneous vector datasets, mostly consisting in elevation contour lines and elevation points derived from several sources. The input vector database was carefully cleaned up to obtain an improved seamless TIN refined by using the DEST algorithm, thus improving the Delaunay tessellation. The whole TINITALY/01 DEM was converted in grid format (10-m cell size) according to a tiled structure composed of 193, 50-km side square elements. The grid database consists of more than 3 billions of cells and occupies almost 12 GB of disk memory. A web-GIS has been created (http://tinitaly.pi.ingv.it/ ) where a seamless layer of images in full resolution (10 m) obtained from the whole DEM (both in color-shaded and anaglyph mode) is open for browsing. Accredited navigators are allowed to download the elevation dataset.

Tarquini, S.; Nannipieri, L.; Favalli, M.; Fornaciai, A.; Vinci, S.; Doumaz, F.

2012-04-01

248

An evaluation of LIDAR and IFSAR-derived digital elevation models in leaf-on conditions with USGS Level 1 and Level 2 DEMs  

Microsoft Academic Search

An assessment of four different remote sensing based methods for deriving digital elevation models (DEMs) was conducted in a flood-prone watershed in North Carolina. New airborne LIDAR (light detecting and ranging) and IFSAR (interferometric synthetic aperture radar (SAR)) data were collected and corresponding DEMs created. These new sources were compared to two methods: Gestalt Photomapper (GPM) and contour-to-grid, used by

Michael E. Hodgson; John R. Jensen; Laura Schmidt; Steve Schill; Bruce Davis

2003-01-01

249

New morphometric properties for channel network classification using the graph theory and DEM  

NASA Astrophysics Data System (ADS)

The channel network controls the spatial pattern of hydrological processes within a catchment. Hence the identification of key hydrological features characterising the channel network can contribute to a rational classification of catchments. This presentation aims to investigate morphometric properties of the channel network derived from DEM using the graph theory, and estimate whether these properties can be used as similarity indices for the classification of channel networks. The graph theory was used in order to represent the contributing drainage area which has properties of a scale free network, and was subsequently characterised by highly connected nodes called hubs. The method involves ranking the hubs of a channel network according to the contributing drainage area and the distance to the outlet. The hubs' characteristics can be considered as morphometric descriptors of the channel network and are used to compare and classify channel network. Applications were conducted on 788 French catchments with the same area (between 100 and 105 km2) and on 18 catchments having an area between 43 and 116450 km2. First, we present some newly found invariance properties of headwater subcatchments and show that some invariant morphometric properties characterize only natural channel networks verifying Optimal Channel Networks (OCN) properties, but are not verified for non-OCN (Moussa et al., 2011, Water Resources Research, 47, W08518). A new empirical model based on self-affine properties was developed in order to calculate the number N and the total headwater area H as a function of the cutoff area S used to extract the channel network from DEM. Results show that H(S) / S0 (S0 being the catchment area) is independent from S and seems constant (0.29 +/- 0.03) for various shapes and sizes of channel networks, and consequently can be considered as invariant general descriptor of natural channel networks. On the contrary, this is not the case when the approach is applied on virtual non-OCN. Second, we define new morphometric descriptors on the basis of hub's properties in order to compare channel networks and to answer the following questions: are there any similar channel networks referred as 'twins'? and what channel network resembles most to an other given channel network? (Moussa et al., Water Resources Research, submitted). Two ways of classifications are proposed: the first one according a supervised procedure based on 8 types and a second one according a nested hierarchy considering the main hub as the key factor of the classification. Hence, we identify twelve twins networks among the 788 studied. These results show that the knowledge of six morphometric indices enable to calculate both functions N(S) and H(S) for all values of S < S0. These indices can be considered as geometric and topological properties of channel networks, and are useful for studying the effects of cutoffs on self-affine river networks or as similarity indices for channel network comparison.

Moussa, R.; Colin, F.; Rabotin, M.; A; Crabit

2012-04-01

250

Der Briefwechsel zwischen Sidonie Na?dherny? und Albert Bloch : September 1947-September 1950 : mit einer Einfu?hrung in die Widmungsgedichte von Karl Kraus an Sidonie Na?dherny?  

E-print Network

S. 239. vi von Kraus gewidmeten Gedichten und eine Darstellung ihrer frühen Entwicklung, die Aufschlüsse über ihre spätere Beziehung zu Kraus geben kann, von besonderer Bedeutung. Anna Bloch stellte mir die Kopien der Bloch.../Nädherny-Korrespondenz zugänglich. Borfvoj Indra, Leiter des Staatsarchives in Prag, und Milan BaStar, Leiter der Zweigstelle des Staatsarchives Prag in BeneSov, ermöglichten mir Einblick in Sidonie Nädhernys Privatbriefe und Tagebücher. Die von Heinrich Fischer und dem Bloch...

Champion, Elke Lorenz

1998-01-01

251

Mapping hydrological environments in central Amazonia: ground validation and surface model based on SRTM DEM data corrected for deforestation  

NASA Astrophysics Data System (ADS)

One of the most important freely available digital elevation models (DEMs) for Amazonia is the one obtained by the Shuttle Radar Topography Mission (SRTM). However, since SRTM tends to represent the vegetation surface instead of the ground surface, the broad use of SRTM DEM as a framework for terrain description in Amazonia is hampered by the presence of deforested areas. We present here two data sets: (1) a deforestation-corrected SRTM DEM for the interfluve between the Purus and Madeira rivers, in central Amazonia, which passed through a careful identification of different environments and has deforestation features corrected by a new method of increasing pixel values of the DEM (Rennó, 2009); and (2) a set of 18 hydrological-topographic descriptors based on the corrected SRTM DEM. Deforestation features are related with the opening of an 800 km road in the central part of the interfluve and occupancy of its vicinity. We used topographic profiles from the pristine forest to the deforested feature to evaluate the recovery of the original canopy coverage by minimizing canopy height variation (corrections ranged from 1 to 38 m). The hydrological-topographic description was obtained by the Height Above the Nearest Drainage (HAND) algorithm, which normalizes the terrain elevation (above sea level) by the elevation of the nearest hydrologically connected drainage. The validation of the HAND data set was done by in situ hydrological description of 110 km of walking trails also available in this data set. The new SRTM DEM expands the applicability of SRTM data for landscape modelling; the data sets of hydrological features based on topographic modelling are undoubtedly appropriate for ecological modelling and an important contribution to environmental mapping of Amazonia. The deforestation-corrected SRTM DEM is available at http://ppbio.inpa.gov.br/knb/metacat/naman.318.3/ppbio; the polygons selected for deforestation correction are available at http://ppbio.inpa.gov.br/knb/metacat/naman.317.3/ppbio; the set of hydrological-topographic descriptors is available at http://ppbio.inpa.gov.br/knb/metacat/naman.544.2/ppbio; the environmental description of access trails is available at http://ppbio.inpa.gov.br/knb/metacat/naman.541.2/ppbio; and the limits of deforestation corrections and drainage validation are available at http://ppbio.inpa.gov.br/knb/metacat/liliandias.38.1/ppbio.

Moulatlet, G. M.; Rennó, C. D.; Costa, F. R. C.; Emilio, T.; Schietti, J.

2015-03-01

252

Three-dimensional Distinct Element Method (DEM) modelling of oblique-slip normal faulting  

NASA Astrophysics Data System (ADS)

Normal faults frequently exhibit a strike-slip displacement component, which can arise for example from oblique reactivation or from fault strike changes, e.g. along bends. It is well known from both natural examples and analogue experiments that fault zones developing above oblique normal faults are typically comprised of systematically stepping fault segments. However, dependencies of fault segment orientation and segmentation on fault obliquity and mechanical properties during faulting are poorly understood. For example, it is not clear whether systematically stepping fault segments link preferentially via footwall or hanging wall breaching. Moreover, the persistence of fault bends throughout mechanically layered sequences is another yet unexplored topic. Here we use three-dimensional Distinct Element Method (DEM) modelling to elucidate the geometry and kinematics of fault zones developing above oblique normal faults. We systematically vary both fault obliquity and confining pressure. Fault zone structure (e.g. segment orientations, drag, etc.) is quantified from horizon maps generated at different levels within the model. Irrespective of fault obliquity, fault zones become better localised with increasing confining pressure. Analysis of displacement partitioning at branch-points illustrates that neither footwall nor hanging wall breaching is the preferred mode of segment linkage. Fault segment orientations exhibit a systematic fault obliquity dependence, which can be rationalised using infinitesimal strain theory for transtensional shear zones. Our models therefore suggest that the orientation of fault segments developing above oblique normal faults may be used to estimate the extension direction, as suggested nearly 30 years ago by A.M. McCoss [1986, J. Struct. Geol. 8(6), p. 715-718].

Schöpfer, Martin; Childs, Conrad; Manzocchi, Tom; Walsh, John

2014-05-01

253

Formation of fluvial knickzones in Japanese mountainous areas: A spatial analysis using GIS and DEMs  

NASA Astrophysics Data System (ADS)

Fluvial knickzones are the elements of bedrock rivers that can enhance stream erosion into bedrock, and they can be key morphologies highlighting interactions among earth surface processes such as erosion, tectonics, and volcanism. This study examines the longitudinal profiles of Japanese mountain rivers to illustrate the distribution of knickzones and discusses their role in the landscape development. Using 50-m DEMs, knickzones were extracted based on a quantitative criterion, and 5,753 knickzones were identified in the rivers of ca. 65,000 km long. The location of the knickzones was then examined along with other GIS data including topography, geology and precipitation. Overall, topographical conditions have the strongest influences on knickzone abundance, and upstream steep reaches of the rivers are more favorable for knickzone existence. The knickzone abundance for each rock type is also controlled by stream gradients, and lighologic boundaries do not show significant correlations with the knickzone locations. The controls of lithologic substrate on the knickzone locations are therefore limited. The abundant knickzones in steep river reaches indicate a hydraulic origin of knickzones, where stream erosions have enough strength in shaping the bedrock. Moreover, the knickzones are frequently observed in reaches slightly upstream from the major confluences at which stream discharge abruptly increases, indicating that the hydraulic anomalies of water flows at the confluences can cause knickzones which may later migrate upstream. The other possible causes of knickzone initiation including volcanic, tectonic and climatic effects are also suggested. The abundant knickzones in Japanese mountain rivers, resulted from the interactions among surface processes, suggest that river morphology modeling needs to consider the initiation and development of knickzones. tokyo.ac.jp/~hayakawa/

Hayakawa, Y. S.; Oguchi, T.

2006-12-01

254

DEM-based model for reconstructing volcano's morphology from primary volcanic landforms  

NASA Astrophysics Data System (ADS)

Volumes of magma intruded in and emitted by volcanoes through time can be estimated by reconstruction of volcano's morphology and time sequence. Classical approaches for quantifying magma volumes on active volcanoes are based on the difference between pre- and post-eruption digital elevation models (DEM), but this kind of approach needs the pre-eruptive surfaces to be available. For old and eroded volcanoes these surfaces are poorly constrained. However, because the geometrical form of many volcanic edifices exhibits a remarkable symmetry we propose, here, a new approach using primary volcanic landforms in order to estimate the amount of the both erupted and eroded material and to locate eruptive centers. A large fraction of composite volcanoes have near constant slope on their flanks and a form that is concave upwards near their summits. But many phenomena can lead to non-symetrical edifices and complex morphologies can result, for example from parasitic centers of volcanism on the flanks, from alternation of short effusive and explosive construction phases, from flank or caldera collapses, or from glacial and other types of erosion. In this study we propose that, on the first order approximation, complex morphologies can be modeled by piling regular cones. In this model, cones centers and slopes are derived by fitting primary volcanic landform with a linear function :elevation=f(distance from center). Such an approach allows to estimate both errors on location of the eruptive center and on the volume of the resulting cones. This model can then be used for quantifying volume of erupted and eroded material, and for quantifying catastrophic events as giant landslides or flank collapse. This approach is tested on four different active volcanoes : Mount Mayon (Philippines), Mount Fuji (Japan), Mount Etna (Sicily) and Mount Teide (Canary Island) to estimate errors in volume between modeled and actual edifices. It is then used on volcanoes of La Réunion hotspot to reconstruct the Piton des Neiges and Piton de la Fournaise volcanoes at its different stages of growing.

Gayer, Eric; Lopez, Philippe; Michon, Laurent

2014-05-01

255

New insights from DEM's into form, process and causality in Distributive Fluvial Systems  

NASA Astrophysics Data System (ADS)

Recent developments in platforms and sensors, as well as advances in our ability to access these rich data sources in near real time presents geoscientists with both opportunities and problems. We currently record raster and point cloud data about the physical world at unprecedented rates with extremely high spatial and spectral resolution. Yet the ability to extract scientifically useful knowledge from such immense data sets has lagged considerably. The interrelated fields of database creation, data mining and modern geostatistics all focus on such interdisciplinary data analysis problems. In recent years these fields have made great advances in analyzing the complex real-world data such as that captured in Digital Elevation Models (DEM's) and satellite imagery and by LIDAR and other geospatially referenced data sets. However, even considering the vast increase in the use of these data sets in the past decade these methods have enjoyed only a relatively modest penetration into the geosciences when compared to data analysis in other scientific disciplines. In part, a great deal of the current research weakness is due to the lack of a unifying conceptual approach and the failure to appreciate the value of highly structured and synthesized compilations of data, organized in user-friendly formats. We report on the application of these new technologies and database approaches to global scale parameterization of Distributive Fluvial Systems (DFS) within continental sedimentary basins and illustrate the value of well-constructed databases and tool-rich analysis environments for understanding form, process and causality in these systems. We analyzed the characteristics of aggradational fluvial systems in more than 700 modern continental sedimentary basins and the links between DFS within these systems and their contributing drainage basins. Our studies show that in sedimentary basins, distributive fluvial and alluvial systems dominate the depositional environment. Consequently, we have found that studies of modern tributary drainage systems in degradational settings are likely insufficient for understanding the geomorphology expressed within these basins and ultimately for understanding the basin-scale architecture of dominantly distributive fluvial deposits preserved in the rock record.

Scuderi, Louis; Weissmann, Gary; Hartley, Adrian; Kindilien, Peter

2014-05-01

256

Forecasting of Storm-Surge Floods Using ADCIRC and Optimized DEMs  

NASA Technical Reports Server (NTRS)

Increasing the accuracy of storm-surge flood forecasts is essential for improving preparedness for hurricanes and other severe storms and, in particular, for optimizing evacuation scenarios. An interactive database, developed by WorldWinds, Inc., contains atlases of storm-surge flood levels for the Louisiana/Mississippi gulf coast region. These atlases were developed to improve forecasting of flooding along the coastline and estuaries and in adjacent inland areas. Storm-surge heights depend on a complex interaction of several factors, including: storm size, central minimum pressure, forward speed of motion, bottom topography near the point of landfall, astronomical tides, and, most importantly, maximum wind speed. The information in the atlases was generated in over 100 computational simulations, partly by use of a parallel-processing version of the ADvanced CIRCulation (ADCIRC) model. ADCIRC is a nonlinear computational model of hydrodynamics, developed by the U.S. Army Corps of Engineers and the US Navy, as a family of two- and three-dimensional finite-element-based codes. It affords a capability for simulating tidal circulation and storm-surge propagation over very large computational domains, while simultaneously providing high-resolution output in areas of complex shoreline and bathymetry. The ADCIRC finite-element grid for this project covered the Gulf of Mexico and contiguous basins, extending into the deep Atlantic Ocean with progressively higher resolution approaching the study area. The advantage of using ADCIRC over other storm-surge models, such as SLOSH, is that input conditions can include all or part of wind stress, tides, wave stress, and river discharge, which serve to make the model output more accurate. To keep the computational load manageable, this work was conducted using only the wind stress, calculated by using historical data from Hurricane Camille, as the input condition for the model. Hurricane storm-surge simulations were performed on an eight-node Linux computer cluster. Each node contained dual 2-GHz processors, 2GB of memory, and a 40GB hard drive. The digital elevation model (DEM) for this region was specified using a combination of Navy data (over water), NOAA data (for the coastline), and optimized Interferometric Synthetic Aperture Radar data (over land). This high-resolution topographical data of the Mississippi coastal region provided the ADCIRC model with improved input with which to calculate improved storm-surge forecasts.

Valenti, Elizabeth; Fitzpatrick, Patrick

2006-01-01

257

With high resolution DEM to enhanced maps of Dominant Runoff Processes (DRP)  

NASA Astrophysics Data System (ADS)

The reaction of a river on intense rainfall depends on the distribution of the dominant runoff processes (DRP) Hortonian Overland Flow (HOF), Saturated Overland Flow (SOF), Sub-surface Flow (SSF) or Deep Percolation (DP) within its catchment area. A decision scheme to determine the DRP was implemented in a GIS, using high resolution data of soils, geology, land use and topography. With the scheme, a DRP map was derived for the Kanton of Zurich with an area of 1730 km2, which lies in the Swiss Plateau and covers a wide range of topography, geology and flood producing precipitation regimes. Detailed soil maps are essential for the derivation of high resolution dominant runoff processes maps because they contain information about the soil infiltration and the storage capacity. In the Kanton of Zurich, only a small part of the forested areas is covered by detailed soil maps. Information like soil depth and soil water regime had to be derived from the forest vegetation map (1:5'000). In this map, species of plants, grouped to forest communities, are delineated, depending on their preferred site conditions. Besides geology, topography and climate, also soil water regime and soil depth influence the occurence of plant species. However, a comparison between the soil water regime, indicated by detailed soil maps and the forest vegetation map shows that not all forest communities are selective for the soil water regime and soil depth. Thus, only some forest communities can be used, to derive the DRP. For the other forest communities, an automatic method had to be developed to derive soil water regime and soil depth, based on a high resolution geological map and a laser scanned DEM. With the high resolution topographic information, small creeks, drainage ditches and erosion ditches could be identified. These areas indicate where a fast runoff reaction during heavy rainfalls can be expected. Creeks and drainage ditches suggest that soils do not drain properly and are saturated. Erosion ditches indicate the generation of quick SOF, caused by limited soil depth. In 20 catchments of different sizes, with different topography and different geology, the automatically derived DRP maps were compared with manually developed ones. In 80% to 99%, the automatically derived DRP areas match the manually developed ones or differ by 1 step in process intensity. As this method allows the derivation of enhanced DRP maps in high resolution, the DRP maps can also be used to forecast the runoff reaction of small catchments.

Margreth, Michael; Naef, Felix

2010-05-01

258

Effects of Historical Landslide distribution and DEM resolution on the Accuracy of Landslide susceptibility mapping using Artificial Neural Network  

NASA Astrophysics Data System (ADS)

An efficient and accurate method of generating landslide susceptibility maps is very important to mitigate the loss of properties and lives caused by this type of geological hazard. The study area is Niigata, Japan sustained extensive landslide damage triggered by earthquake on 2004. This study focuses on the development of an accurate and efficient method of data integration, processing and generation of a landslide susceptibility map using an ANN (Artificial Neural Network), and data from some type of DEM (Digital Elevation Models) and landslide distribution map. DEM was generated from aerial photograph, laser scanning data, topographic map and ASTER. Two Landslide distribution maps are derived from NIED and GSI. The effects of the DEM resolution and landslide distribution on the accuracy of landslide susceptibility mapping has been analyzed using ANN in this study. The method contains two major phases. The first phase is the data integration and analysis, and the second is the artificial neural network training and mapping. The data integration and analysis phase involves GIS based statistical analysis relating landslide occurrence to geological and geomorphological parameters. The parameters include slope, aspect, elevation and geology. This phase determines the geological and geomorphological factors that are significantly correlated with landslide occurrence. The second phase further relates the landslide susceptibility index to the important geological and geomorphological parameters identified in the first phase through ANN training. The trained ANN is then used to generate a landslide susceptibility map. The area provided enough landslide data to check the efficiency and accuracy of the developed method. Based on the initial results of the experiment, the developed method is more than 90% accurate in determining the probability of landslide occurrence in a particular area.

Kawabata, D.; Bandibas, J.

2013-12-01

259

Airborne LiDAR DEMs as a tool for deriving information on past glacier extent and ice flow  

NASA Astrophysics Data System (ADS)

The quantification of ice volumes and the identification of ice flow regimes within historical glacier systems are important steps towards understanding historical phases of glacier advance and disintegration in the context of Holocene climate fluctuation. Topographic LiDAR DEMs provide an excellent tool for gaining various kinds of spatially distributed information. Several case studies have been performed in the Austrian Alps, where LiDAR DEMs are available for almost the entire glacier area. LiDAR DEMs achieve vertical accuracies of few decimetres and can be used to calculate hillshade images with flat incidence angles, so that the surface structures of moraines and other glacial deposits can be identified. These hillshade images were used together with aerial photographs to identify the LIA (Little Ice Age) moraines and the elevation of the lateral moraines, so that, together with information on today's ice volume, a lower limit for the LIA ice volume could be calculated. The resulting LIA glacier areas showed good coincidence with former reconstructions based on field mapping and airborne photogrammetry. In addition to that, historical ice flow directions could be derived from the structure of basal moraines. These data allow an interpretation of the changing contribution of specific tributary glaciers to a joint glacier tongue, which may result in an important switch in ice dynamics leading to fast glacier advances recorded by frontal moraines. The combination of terrestrial long-term observations and LiDAR data documents the genesis of specific geomorphological features in the periglacial area by recording the processes occurring during the disintegration of glacier tongues. For example, the deposition of the material from former medial moraines in the newly formed periglacial area can be identified and quantified from the LiDAR data as well as debris flows or rock falls from the LIA moraines.

Seiser, Bernd; Fischer, Andrea

2014-05-01

260

Dem Assessment Derived from Close Range Photogrammetry: a Case Study from Kadavur Area, Karur District, Tamil Nadu, India  

NASA Astrophysics Data System (ADS)

Close-Range Photogrammetry is an accurate, cost effective technique of collecting measurements of real world objects and conditions, directly from photographs. Photogrammetry utilizes digital images to obtain accurate measurements and geometric data of the object or area of interest, in order to provide spatial information for Engineering design, spatial surveys or 3D modeling. The benefits of close-range Photogrammetry over other field procedures are purported to be: Increased accuracy; complete as-built information; reduced costs; reduced on-site time; and effective for small and large projects. The same basic principle of traditional Aerial Photogrammetry can be applied to stereoscopic pictures taken from lower altitudes or from the ground. Terrestrial, ground-based, and close-range are all descriptive terms that refer to photos taken with an object-to-camera distance less than 300m (1000 feet). (Matthews, N.A, 2008). Close range Photogrammetry is a technique for obtaining the geometric information (e.g. position, distance, size and shape) of any object in 3D space that was imaged on the two dimensional (2D) photos, (Wolf, P.R, et.al, 2000) DEM Generation requires many processing and computation, such as camera calibration, stereo matching, editing, and interpolation. All the mentioned steps contribute to the quality of DEM. Image on close range Photogrammetry can be captured using three kind of camera: metric camera, semi-metric camera, and non-metric camera (Hanke, K., et.al, 2002). In this paper DEM quality assessed at Kadavur area, Karur district, Tamil Naudu, India using Close Range Photogrammetry technique, Commercial Digital Camera and Leica Photogrammetry Suite.

Anbarasan, S.; Sakthivel, R.

2012-07-01

261

Direct micromechanics derivation and DEM confirmation of the elastic moduli of isotropic particulate materials:. Part II Particle rotation  

NASA Astrophysics Data System (ADS)

In Part I, Fleischmann et al. (2013), we performed theoretical analyses of three cubic packings of uniform spheres (simple, body-centered, and face-centered) assuming no particle rotation, employed these results to derive the effective elastic moduli for a statistically isotropic particulate material, and assessed these results by performing numerical discrete element method (DEM) simulations with particle rotations prohibited. In this second part, we explore the effect that particle rotation has on the overall elastic moduli of a statistically isotropic particulate material. We do this both theoretically, by re-analyzing the elementary cells of the three cubic packings with particle rotation allowed, which leads to the introduction of an internal parameter to measure zero-energy rotations at the local level, and numerically via DEM simulations in which particle rotation is unrestrained. We find that the effects of particle rotation cannot be neglected. For unrestrained particle rotation, we find that the self-consistent homogenization assumption applied to the locally body-centered cubic packing incorporating particle rotation effects most accurately predicts the measured values of the overall elastic moduli obtained from the DEM simulations, in particular Poisson's ratio. Our new self-consistent results and theoretical modeling of particle rotation effects together lead to significantly better theoretical predictions of Poisson's ratio than all prior published results. Moreover, our results are based on a direct micromechanics analysis of specific geometrical packings of uniform spheres, in contrast to prior theoretical analyses based on hypotheses involving overall inter-particle contact distributions. Thus, our results permit a direct assessment of the reasons for the theory-experiment discrepancies noted in the literature with regard to previous theoretical derivations of the macroscopic elastic moduli for particulate materials, and our new theoretical results greatly narrow such discrepancies.

Fleischmann, J. A.; Drugan, W. J.; Plesha, M. E.

2013-07-01

262

SveDem, the Swedish Dementia Registry – A Tool for Improving the Quality of Diagnostics, Treatment and Care of Dementia Patients in Clinical Practice  

PubMed Central

Background The Swedish Dementia Registry (SveDem) was developed with the aim to improve the quality of diagnostic work-up, treatment and care of patients with dementia disorders in Sweden. Methods SveDem is an internet based quality registry where several indicators can be followed over time. It includes information about the diagnostic work-up, medical treatment and community support (www.svedem.se). The patients are diagnosed and followed-up yearly in specialist units, primary care centres or in nursing homes. Results The database was initiated in May 2007 and covers almost all of Sweden. There were 28 722 patients registered with a mean age of 79.3 years during 2007–2012. Each participating unit obtains continuous online statistics from its own registrations and they can be compared with regional and national data. A report from SveDem is published yearly to inform medical and care professionals as well as political and administrative decision-makers about the current quality of diagnostics, treatment and care of patients with dementia disorders in Sweden. Conclusion SveDem provides knowledge about current dementia care in Sweden and serves as a framework for ensuring the quality of diagnostics, treatment and care across the country. It also reflects changes in quality dementia care over time. Data from SveDem can be used to further develop the national guidelines for dementia and to generate new research hypotheses. PMID:25695768

Religa, Dorota; Fereshtehnejad, Seyed-Mohammad; Cermakova, Pavla; Edlund, Ann-Katrin; Garcia-Ptacek, Sara; Granqvist, Nicklas; Hallbäck, Anne; Kåwe, Kerstin; Farahmand, Bahman; Kilander, Lena; Mattsson, Ulla-Britt; Nägga, Katarina; Nordström, Peter; Wijk, Helle; Wimo, Anders; Winblad, Bengt; Eriksdotter, Maria

2015-01-01

263

Hydrography change detection: the usefulness of surface channels derived From LiDAR DEMs for updating mapped hydrography  

USGS Publications Warehouse

The 1:24,000-scale high-resolution National Hydrography Dataset (NHD) mapped hydrography flow lines require regular updating because land surface conditions that affect surface channel drainage change over time. Historically, NHD flow lines were created by digitizing surface water information from aerial photography and paper maps. Using these same methods to update nationwide NHD flow lines is costly and inefficient; furthermore, these methods result in hydrography that lacks the horizontal and vertical accuracy needed for fully integrated datasets useful for mapping and scientific investigations. Effective methods for improving mapped hydrography employ change detection analysis of surface channels derived from light detection and ranging (LiDAR) digital elevation models (DEMs) and NHD flow lines. In this article, we describe the usefulness of surface channels derived from LiDAR DEMs for hydrography change detection to derive spatially accurate and time-relevant mapped hydrography. The methods employ analyses of horizontal and vertical differences between LiDAR-derived surface channels and NHD flow lines to define candidate locations of hydrography change. These methods alleviate the need to analyze and update the nationwide NHD for time relevant hydrography, and provide an avenue for updating the dataset where change has occurred.

Poppenga, Sandra K.; Gesch, Dean B.; Worstell, Bruce B.

2013-01-01

264

Co-seismic landslide topographic analysis based on multi-temporal DEM-A case study of the Wenchuan earthquake.  

PubMed

Hillslope instability has been thought to be one of the most important factors for landslide susceptibility. In this study, we apply geomorphic analysis using multi-temporal DEM data and shake intensity analysis to evaluate the topographic characteristics of the landslide areas. There are many geomorphologic analysis methods such as roughness, slope aspect, which are also as useful as slope analysis. The analyses indicate that most of the co-seismic landslides occurred in regions with roughness, hillslope and slope aspect of >1.2, >30, and between 90 and 270, respectively. However, the intersection regions from the above three methods are more accurate than that derived by applying single topographic analysis method. The ground motion data indicates that the co-seismic landslides mainly occurred on the hanging wall side of Longmen Shan Thrust Belt within the up-down and horizontal peak ground acceleration (PGA) contour of 150 PGA and 200 gal, respectively. The comparisons of pre- and post-earthquake DEM data indicate that the medium roughness and slope increased, the roughest and steepest regions decreased after the Wenchuan earthquake. However, slope aspects did not even change. Our results indicate that co-seismic landslides mainly occurred at specific regions of high roughness, southward and steep sloping areas under strong ground motion. Co-seismic landslides significantly modified the local topography, especially the hillslope and roughness. The roughest relief and steepest slope are significantly smoothed; however, the medium relief and slope become rougher and steeper, respectively. PMID:24171155

Ren, Zhikun; Zhang, Zhuqi; Dai, Fuchu; Yin, Jinhui; Zhang, Huiping

2013-01-01

265

DEM-based Approaches for the Identification of Flood Prone Areas  

NASA Astrophysics Data System (ADS)

The remarkable number of inundations that caused, in the last decades, thousands of deaths and huge economic losses, testifies the extreme vulnerability of many Countries to the flood hazard. As a matter of fact, human activities are often developed in the floodplains, creating conditions of extremely high risk. Terrain morphology plays an important role in understanding, modelling and analyzing the hydraulic behaviour of flood waves. Research during the last 10 years has shown that the delineation of flood prone areas can be carried out using fast methods that relay on basin geomorphologic features. In fact, the availability of new technologies to measure surface elevation (e.g., GPS, SAR, SAR interferometry, RADAR and LASER altimetry) has given a strong impulse to the development of Digital Elevation Models (DEMs) based approaches. The identification of the dominant topographic controls on the flood inundation process is a critical research question that we try to tackle with a comparative analysis of several techniques. We reviewed four different approaches for the morphological characterization of a river basin with the aim to provide a description of their performances and to identify their range of applicability. In particular, we explored the potential of the following tools. 1) The hydrogeomorphic method proposed by Nardi et al. (2006) which defines the flood prone areas according to the water level in the river network through the hydrogeomorphic theory. 2) The linear binary classifier proposed by Degiorgis et al. (2012) which allows distinguishing flood-prone areas using two features related to the location of the site under exam with respect to the nearest hazard source. The two features, proposed in the study, are the length of the path that hydrologically connects the location under exam to the nearest element of the drainage network and the difference in elevation between the cell under exam and the final point of the same path. 3) The method by Manfreda et al. (2011) that suggested a modified Topographic Index (TIm) for the identification of flood prone area. 4) The downslope index proposed by Hjerdt et al. (2004) that quantifies the topographic controls on hydrology by evaluating head differences following the (surface) flow path in the steepest direction. The method does not use the exit point at the stream as reference; instead, the algorithm looks at how far a parcel of water has to travel along its flow path to lose a given head potential, d [m]. This last index was not defined with the aim to describe flood prone areas; in fact it represents an interesting alternative descriptor of morphological features that deserve to be tested. Analyses have been carried out for some Italian catchments. The outcomes of the four methods are presented using, for calibration and validation purposes, flood inundation maps made available by River Basin Authorities. The aim is, therefore, to evaluate the reliability and the relative errors in the detection of the areas subject to the flooding hazard. These techniques should not be considered as an alternative of traditional procedures, but additional tool for the identification of flood-prone areas and hazard graduation over large regions or when a preliminary identification is needed. Reference Degiorgis M., G. Gnecco, S. Gorni, G. Roth, M. Sanguineti, A. C. Taramasso, Classifiers for the detection of flood-prone areas using remote sensed elevation data, J. Hydrol., 470-471, 302-315, 2012. Hjerdt, K. N., J. J. McDonnell, J. Seibert, A. Rodhe, A new topographic index to quantify downslope controls on local drainage, Water Resour. Res., 40, W05602, 2004. Manfreda, S., M. Di Leo, A. Sole, Detection of Flood Prone Areas using Digital Elevation Models, Journal of Hydrologic Engineering, Vol. 16, No. 10, 781-790, 2011. Nardi, F., E. R. Vivoni, S. Grimaldi, Investigating a floodplain scaling relation using a hydrogeomorphic delineation method, Water Resour. Res., 42, W09409, 2006.

Samela, Caterina; Manfreda, Salvatore; Nardi, Fernando; Grimaldi, Salvatore; Roth, Giorgio; Sole, Aurelia

2013-04-01

266

Low-altitude remote sensing dataset of DEM and RGB mosaic for AB corridor on July 13 2013 and L2 corridor on July 21 2013  

DOE Data Explorer

Low-altitude remote sensing dataset including DEM and RGB mosaic for AB (July 13 2013) and L2 corridor (July 21 2013).Processing flowchart for each corridor:Ground control points (GCP, 20.3 cm square white targets, every 20 m) surveyed with RTK GPS. Acquisition of RGB pictures using a Kite-based platform. Structure from Motion based reconstruction using hundreds of pictures and GCP coordinates. Export of DEM and RGB mosaic in geotiff format (NAD 83, 2012 geoid, UTM zone 4 north) with pixel resolution of about 2 cm, and x,y,z accuracy in centimeter range (less than 10 cm). High-accuracy and high-resolution inside GCPs zone for L2 corridor (500x20m), AB corridor (500x40) DEM will be updated once all GCPs will be measured. Only zones between GCPs are accurate although all the mosaic is provided.

Baptiste Dafflon

267

Precision estimation and geomorphological analysis based on the DEM generated by InSAR: Taking Damxung-Yangbajain area as an example  

Microsoft Academic Search

Digital elevation model (DEM) can be generated by interferometric synthetic aperture radar (InSAR). In this paper, the interferometric\\u000a processing and analyses are carried out for Damxung-Yangbajain area in Tibet, using a pair of Europe remote-sensing satellite\\u000a (ERS)-1\\/2 tandem SAR images acquired on 6 and 7 April 1996. A portion of the In-SAR-derived DEM is selected and compared with\\u000a the 1:50

Yaqiong Dai; Jinwei Ren; Xuhui Shen; Jingfa Zhang; Shunying Hong

2009-01-01

268

Analysis of the seasonal and interannual evolution of Jakobshavn Isbrae from 2010-2013 using high spatial/temporal resolution DEM and velocity data  

NASA Astrophysics Data System (ADS)

Greenland's large marine-terminating outlet glaciers have displayed marked retreat, speedup, and thinning in recent decades. Jakobshavn Isbrae, one of Greenland's largest outlet glaciers, has retreated ~15 km, accelerated ~150%, and thinned ~200 m since the early 1990s. Here, we present the first comprehensive analysis of high spatial (~2-5 m/px) and temporal (daily-monthly) resolution elevation and velocity data for Jakobshavn from 7/2010 to 7/2013. We have developed an automated processing pipeline using open-source software (Ames Stereo Pipeline, GDAL/OGR, NumPy/SciPy, etc.) to produce orthoimage, digital elevation model (DEM), and surface velocity products from DigitalGlobe WorldView-1/2 stereo imagery (~0.5 m/px, ~17 km swath width). Our timeseries consists of 35 WV DEMs (~2-4 m/px) covering the lower trunks of the main+north branches and fjord, but also extending >110 km inland. We supplement this record with 7 TanDEM-X DEMs (~5 m/px, ~35 km swath width) between 6/2011-9/2012. Elevation data from IceBridge ATM/LVIS, ICESat GLAS, and GPS campaigns provide absolute control data over fixed surfaces (i.e., exposed bedrock). Observed WV DEM offsets are consistent with DigitalGlobe's published value of 5.0 m CE90/LE90 horizontal/vertical accuracy. After DEM co-registration, we observe sub-meter horizontal and vertical absolute accuracy. Velocity data are derived from TerraSAR-X data with 11 day repeat interval. Supplemental velocity data are derived through correlation of high-resolution WV DEM/image data. The contemporaneous DEM and velocity data provide full 3D displacement vectors for each time interval, allowing for the analysis of both Eulerian and Lagrangian elevation change. The lower trunk of Jakobshavn displays significant seasonal velocity variations, with recent rates of ~8 km/yr during winter to >17 km/yr during summer. DEM data show corresponding elevation changes of -30 to -45 m in summer and +15 to +20 m in winter, corresponding to integrated volumes of -1.0 to -1.5 km3 and +0.3 to +0.6 km3 for the lower ~20 km of the main trunk. Further analysis will characterize the upstream propagation of the seasonal elevation change and the relationship with observed strain rates. Seasonal surface mass balance elevation changes are also observed over adjacent grounded, slow-moving (~100 m/yr) regions. The DEM timeseries shows a net interannual thinning trend of -15-20 m/yr for lower Jakobshavn, with decreasing magnitude upstream. This is consistent with long-term altimetry records. Interannual thinning of ~2 m/yr and lateral retreat is also observed for grounded ice sheet margins. These DEM and velocity data capture the timing, magnitude and evolution of dynamic thinning/thickening with unprecedented spatial and temporal resolution. These results also emphasize the importance of dense temporal elevation data when characterizing ice sheet variability and interpreting deviations from long-term records. Similar high-resolution timeseries are available for all major outlet glaciers and ice streams in Greenland and Antarctica. Ultimately, these observations will improve our understanding of outlet glacier behavior, while complementing ongoing efforts to constrain estimates for ice-sheet mass balance and contribution to present/future sea level rise.

Shean, D. E.; Joughin, I. R.; Smith, B. E.; Moratto, Z. M.; Alexandrov, O.; Floricioiu, D.; Morin, P. J.; Porter, C. C.; Beyer, R. A.; Fong, T.

2013-12-01

269

The evaluation of unmanned aerial system-based photogrammetry and terrestrial laser scanning to generate DEMs of agricultural watersheds  

NASA Astrophysics Data System (ADS)

Agricultural watersheds tend to be places of intensive farming activities that permanently modify their microtopography. The surface characteristics of the soil vary depending on the crops that are cultivated in these areas. Agricultural soil microtopography plays an important role in the quantification of runoff and sediment transport because the presence of crops, crop residues, furrows and ridges may impact the direction of water flow. To better assess such phenomena, 3-D reconstructions of high-resolution agricultural watershed topography are essential. Fine-resolution topographic data collection technologies can be used to discern highly detailed elevation variability in these areas. Knowledge of the strengths and weaknesses of existing technologies used for data collection on agricultural watersheds may be helpful in choosing an appropriate technology. This study assesses the suitability of terrestrial laser scanning (TLS) and unmanned aerial system (UAS) photogrammetry for collecting the fine-resolution topographic data required to generate accurate, high-resolution digital elevation models (DEMs) in a small watershed area (12 ha). Because of farming activity, 14 TLS scans (? 25 points m- 2) were collected without using high-definition surveying (HDS) targets, which are generally used to mesh adjacent scans. To evaluate the accuracy of the DEMs created from the TLS scan data, 1098 ground control points (GCPs) were surveyed using a real time kinematic global positioning system (RTK-GPS). Linear regressions were then applied to each DEM to remove vertical errors from the TLS point elevations, errors caused by the non-perpendicularity of the scanner's vertical axis to the local horizontal plane, and errors correlated with the distance to the scanner's position. The scans were then meshed to generate a DEMTLS with a 1 × 1 m spatial resolution. The Agisoft PhotoScan and MicMac software packages were used to process the aerial photographs and generate a DEMPSC (Agisoft PhotoScan) and DEMMCM (MicMac), respectively, with spatial resolutions of 1 × 1 m. Comparing the DEMs with the 1098 GCPs showed that the DEMTLS was the most accurate data product, with a root mean square error (RMSE) of 4.5 cm, followed by the DEMMCM and the DEMPSC, which had RMSE values of 9.0 and 13.9 cm, respectively. The DEMPSC had absolute errors along the border of the study area that ranged from 15.0 to 52.0 cm, indicating the presence of systematic errors. Although the derived DEMMCM was accurate, an error analysis along a transect showed that the errors in the DEMMCM data tended to increase in areas of lower elevation. Compared with TLS, UAS is a promising tool for data collection because of its flexibility and low operational cost. However, improvements are needed in the photogrammetric processing of the aerial photographs to remove non-linear distortions.

Ouédraogo, Mohamar Moussa; Degré, Aurore; Debouche, Charles; Lisein, Jonathan

2014-06-01

270

Numerical slope stability simulations of chasma walls in Valles Marineris/Mars using a distinct element method (dem).  

NASA Astrophysics Data System (ADS)

NUMERICAL SLOPE STABILITY SIMULATIONS OF CHASMA WALLS IN VALLES MARINERIS/MARS USING A DISTINCT ELEMENT METHOD (DEM). B. Imre (1) (1) German Aerospace Center, Berlin Adlershof, bernd.imre@gmx.net The 8- to 10-km depths of Valles Marineris (VM) offer excellent views into the upper Martian crust. Layering, fracturing, lithology, stratigraphy and the content of volatiles have influenced the evolution of the Valles Marineris wallslopes. But these parameters also reflect the development of VM and its wall slopes. The scope of this work is to gain understanding in these parameters by back-simulating the development of wall slopes. For that purpose, the two dimensional Particle Flow Code PFC2D has been chosen (ITASCA, version 2.00-103). PFC2D is a distinct element code for numerical modelling of movements and interactions of assemblies of arbitrarily sized circular particles. Particles may be bonded together to represent a solid material. Movements of particles are unlimited. That is of importance because results of open systems with numerous unknown variables are non-unique and therefore highly path dependent. This DEM allows the simulation of whole development paths of VM walls what makes confirmation of the model more complete (e.g. Oreskes et al., Science 263, 1994). To reduce the number of unknown variables a proper (that means as simple as possible) field-site had to be selected. The northern wall of eastern Candor Chasma has been chosen. This wall is up to 8-km high and represents a significant outcrop of the upper Martian crust. It is quite uncomplex, well-aligned and of simple morphology. Currently the work on the model is at the stage of performing the parameter study. Results will be presented via poster by the EGS-Meeting.

Imre, B.

2003-04-01

271

Comparative FEM and DEM modeling of basement-involved thrust structures, with application to Sheep Mountain, Greybull area, Wyoming  

NASA Astrophysics Data System (ADS)

Basement-involved fold and thrust systems have been widely studied in several locations, through field and seismic investigations. However, our understanding of the geometries of the faults that drive folding, and the mechanical conditions within the resulting folds, is still limited. Simulations run using the finite element and discrete element methods have great potential to help determine the mechanical evolution of structures at all scales. Both methods have been employed to explore the structural evolution of the Laramide-age Sheep Mountain anticline, located in the eastern Bighorn Basin of Wyoming. Both sets of simulations are constrained by experimental and well log data, and use the same size model domain and mechanical stratigraphy. The underlying basement-sediment boundary was deformed by a set of prescribed displacements. The results of the two simulations are geometrically similar, and match previous field-based interpretations of the Sheep Mountain fold to the first order. Stresses calculated by the two methods were also very similar, thus verifying the mechanical comparison. Differences in the geometric details, however, provide important perspectives on the capabilities of the two methods. For example, the major faults producing the Sheep Mountain fold develop slightly higher dips in the DEM simulation than the FEM simulation, yielding a better match with published interpretations. The crest of the anticline is characterized by distributed thinning of shallow strata in the FEM simulation, and by local extensional faulting in the DEM simulation. Neither simulation reproduced the north-south fold splay observed in the field, suggesting that this minor feature results from preexisting structure or 3D effects not modeled here.

Zhang, Jie; Morgan, Julia K.; Gray, Gary G.; Harkins, Nathan W.; Sanz, Pablo F.; Chikichev, Ivan

2013-11-01

272

Automated classifications of topography from DEMs by an unsupervised nested-means algorithm and a three-part geometric signature  

USGS Publications Warehouse

An iterative procedure that implements the classification of continuous topography as a problem in digital image-processing automatically divides an area into categories of surface form; three taxonomic criteria-slope gradient, local convexity, and surface texture-are calculated from a square-grid digital elevation model (DEM). The sequence of programmed operations combines twofold-partitioned maps of the three variables converted to greyscale images, using the mean of each variable as the dividing threshold. To subdivide increasingly subtle topography, grid cells sloping at less than mean gradient of the input DEM are classified by designating mean values of successively lower-sloping subsets of the study area (nested means) as taxonomic thresholds, thereby increasing the number of output categories from the minimum 8 to 12 or 16. Program output is exemplified by 16 topographic types for the world at 1-km spatial resolution (SRTM30 data), the Japanese Islands at 270??m, and part of Hokkaido at 55??m. Because the procedure is unsupervised and reflects frequency distributions of the input variables rather than pre-set criteria, the resulting classes are undefined and must be calibrated empirically by subsequent analysis. Maps of the example classifications reflect physiographic regions, geological structure, and landform as well as slope materials and processes; fine-textured terrain categories tend to correlate with erosional topography or older surfaces, coarse-textured classes with areas of little dissection. In Japan the resulting classes approximate landform types mapped from airphoto analysis, while in the Americas they create map patterns resembling Hammond's terrain types or surface-form classes; SRTM30 output for the United States compares favorably with Fenneman's physical divisions. Experiments are suggested for further developing the method; the Arc/Info AML and the map of terrain classes for the world are available as online downloads. ?? 2006 Elsevier B.V. All rights reserved.

Iwahashi, J.; Pike, R.J.

2007-01-01

273

freenet Sync auf dem iPhone einrichten Diese Anleitung beschreibt die Einstellungen zur freenet Sync Konfiguration Ihres iPhones.  

E-print Network

freenet Sync auf dem iPhone einrichten Diese Anleitung beschreibt die Einstellungen zur freenet Sync Konfiguration Ihres iPhones. Schritt 1: Tippen Sie in Ihrem Home-Screen auf "Einstellungen". #12 anschlie�end oben rechts auf "Weiter". #12;Schritt 6: Füllen Sie nun das Feld "Server" aus. Die Adresse des

Gediga, Günther

274

MARE2DEM: an open-source code for anisotropic inversion of controlled-source electromagnetic and magnetotelluric data using parallel adaptive 2D finite elements (Invited)  

NASA Astrophysics Data System (ADS)

This work announces the public release of an open-source inversion code named MARE2DEM (Modeling with Adaptively Refined Elements for 2D Electromagnetics). Although initially designed for the rapid inversion of marine electromagnetic data, MARE2DEM now supports a wide variety of acquisition configurations for both offshore and onshore surveys that utilize electric and magnetic dipole transmitters or magnetotelluric plane waves. The model domain is flexibly parameterized using a grid of arbitrarily shaped polygonal regions, allowing for complicated structures such as topography or seismically imaged horizons to be easily assimilated. MARE2DEM efficiently solves the forward problem in parallel by dividing the input data parameters into smaller subsets using a parallel data decomposition algorithm. The data subsets are then solved in parallel using an automatic adaptive finite element method that iterative solves the forward problem on successively refined finite element meshes until a specified accuracy tolerance is met, thus freeing the end user from the burden of designing an accurate numerical modeling grid. Regularized non-linear inversion for isotropic or anisotropic conductivity is accomplished with a new implementation of Occam's method referred to as fast-Occam, which is able to minimize the objective function in much fewer forward evaluations than the required by the original method. This presentation will review the theoretical considerations behind MARE2DEM and use a few recent offshore EM data sets to demonstrate its capabilities and to showcase the software interface tools that streamline model building and data inversion.

Key, K.

2013-12-01

275

Site-specific assessment of the rockfall and the rock block volume distribution relations, using a LIDAR generated DEM  

NASA Astrophysics Data System (ADS)

The quantification of the rockfall hazard and, in particular of the rockfall propagation, requires information on the expected probability or frequency of rockfalls of a given magnitude (size), usually in the form of magnitude-frequency M-F relations. Two kinds of relations are needed. The first one characterises the rockfall masses that can be potentially detached from the slope face giving information on the volume distribution of rockfalls. From now on, this will be referred to as potential rockfall volume distribution VDR. For fragmental rockfalls, the evaluation of the VDR can be a first step towards the temporal M-F, The second one characterises the volume distribution of the rock blocks that result from the disintegration of the previous rockfall masses due to impact with the ground. This one will be referred to as rock block volume distribution VDB. In this work we present two analytical procedures which are independent from the existence of empirical data, for: (i) The calculation of the potential VDR that refers to big volumes with low probability of occurrence. This is realised by detection of the kinematically unstable surfaces on a DEM and on orthophotos, and calculation of the volumes that correspond to them. The basic assumptions here describing a conservative scenario of very low probability are: (a) the rockfall mass is detached entirely at a single rockfall event, without taking into account that smaller successive failures are possible instead; (b) all discontinuity sets are present everywhere in the slope and have infinite persistence; and (c) big stepped-path failures are possible. (ii) The assessment of the in-situ rock blocks volume distribution on the slope face, VDB, by calculation of the volume of the prisms which are formed by the intersection of the existing discontinuity sets and are kinematically unstable. This is also based on data obtained by DEM analysis. A high-resolution DEM obtained by Lidar is used. Both procedures are presented though an application example at the country of Andorra and in particular at the chute of Forat Negre. The results from the first procedure indicate that it is kinematically possible to have mobilised volumes of some thousands of cubic meters although the probability of generating large volumes is low. The VDR for big volume events was well fitted by a power-law equal to -0.5. The VDB from the second procedure, assuming three intersection types within the discontinuity network and two extreme cases of discontinuity persistence, was also found to follow a power-law, with exponent -1.3. The comparison with field data collected by past studies in the same area indicates that in reality, the discontinuities have a very high persistence and that considering only their visible trace length is very conservative.

Mavrouli, Olga; Corominas, Jordi; Jaboyedoff, Michel

2014-05-01

276

Topographic changes due to the 2008 Mw 7.9 Wenchuan earthquake as revealed by the differential DEM method  

NASA Astrophysics Data System (ADS)

Landscape evolution in active orogenic regions is inevitably affected by the repeated strong earthquakes triggered by the corresponding active faults. However, the lack of adequate methods for the documentation and monitoring of mountain-building processes has resulted in a shortage of quantitative estimates of orogenic and eroded volumes. A strong earthquake and its associated co-seismic landslides represent a sudden pulse in landscape evolution in tectonically active areas. The 2008 Mw 7.9 Wenchuan earthquake dramatically modified the topography of the Longmen Shan region. Based on topographic data before the earthquake and stereo pairs of post-earthquake remote sensing imagery, we derived pre- and post-earthquake DEMs (digital elevation models) of the three regions along the Longmen Shan Thrust Belt. By comparing the geomorphic features before and after the earthquake, we find that the Wenchuan earthquake smoothed the steep relief and caused a co-seismic uplift of the Longmen Shan region. The medium-relief regions increased; however, the high-relief regions decreased, indicating that the local relief is controlled by repeated strong earthquakes. The changed slope aspect indicates that the formation and modification of the east- and west-facing slopes are controlled by tectonic events in the Longmen Shan region, which might be associated with the regional stress field. However, the unchanged aspects of other slopes might be controlled by long-term erosion rather than tectonic events. The topographic changes, landslide volume and co-seismic uplift indicate that the greatest seismically induced denudation occurred in association with a thrust faulting mechanism and low-angle fault geometry. Our findings reveal that the local relief has been shaped by the localized, seismically induced high rate of denudation within the plateau margins, and that the formation of local relief is also related to tectonic events, especially the events that have occurred on low-angle faults. This study also indicates that the multi-temporal DEM differential method is valuable in detecting seismically induced topographic change.

Ren, Zhikun; Zhang, Zhuqi; Dai, Fuchu; Yin, Jinhui; Zhang, Huiping

2014-07-01

277

Spatial distribution of incoming potential solar radiation based on solar analyst model and DEM in Xinjiang, China  

NASA Astrophysics Data System (ADS)

Incoming solar radiation is the primary driver for physical and biological process in the earth. Human activities, such as agriculture, forestry, land management, etc, ultimately depend on solar radiation. At a global scale, the geometry of earth's rotation and revolution about the sun cause the gradients of solar radiation. But topography is the major factor modifying the distribution of solar radiation at a landscape scale. Spatial solar radiation models provide a cost-efficient means for understanding the spatial variation of solar radiation over landscape scales. Geographic Information system (GIS) has become established tools for analyzing such models. Among such models, the Solar Analyst draws from the strengths of both point-specific and area-based models. It can calculate solar radiation integrated for any time period. In this paper, this model was used to estimate the spatial distribution of incoming potential solar radiation in Xinjiang, China. The 1km resolution digital elevation model (DEM) derived from 1:250000-scale topographic maps and other topographic factors (altitude, slope, aspect, etc derived from DEM) of Xinjiang were used as the basis for generating digital maps of the important parameter required to run Solar Analyst model. With the assistant of topographic factors and Solar Analyst model, the spatial distribution of monthly incoming potential solar radiation with 1km resolution was estimated. Actual solar radiation data were obtained from 13 meteorological stations for the result validation. Validation determined that the mean relative error (MRE) of incoming potential solar radiation ranges from 3.8% in Jul to 12.2% in Dec and the mean value of monthly MRE is 7.1%. The MRE is larger in winter than in other season. In conclusion, the simulated results of model are basically up to the level of application requirement. The Solar Analyst model may serves as a good tool for estimating spatial patters of monthly incoming potential solar radiation in Xinjiang. Application of Solar Analyst in Xinjiang and analysis of the spatial distribution characteristics of monthly incoming potential solar radiation have great significance for the research fields of agriculture, forestry and ecology in Xinjiang, China.

Li, Jun

2009-10-01

278

Terrain Classification of Aster gDEM for Seismic Microzonation of Port-Au Haiti, Using - and - Based Analytic Methods  

NASA Astrophysics Data System (ADS)

The aftermath of the M7.0 Haiti earthquake of 12 January 2010 witnessed an impressive scientific response from the international community. In addition to conventional post-earthquake investigations, there was also an unprecedented reliance on remote-sensing technologies for scientific investigation and damage assessment. These technologies include sensors from both aerial and space-borne observational platforms. As part of the Haiti earthquake response and recovery effort, we develop a seismic zonation map of Port-au-Prince based on high-resolution satellite imagery as well as data from traditional seismographic monitoring stations and geotechnical site characterizations. Our imagery consists of a global digital elevation model (gDEM) of Hispaniola derived from data recorded by NASA-JPL's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument onboard the multi-platform satellite Terra. To develop our model we also consider recorded waveforms from portable seismographic stations (Hough et al., in review) and 36 geotechnical shear-wave velocity surveys (Cox et al., in review). Following a similar approach developed by Yong et al. (2008; Bull. Seism Soc. Am.), we use both pixel- and object- based imaging analytic methods to systematically identify and extract local terrain features that are expected to amplify seismic ground motion. Using histogram-stretching techniques applied to the rDEM values, followed by multi-resolution, segmentations of the imagery into terrain types, we systematically classify the terrains of Hispaniola. By associating available Vs30 (average shear-wave velocity in the upper 30 meter depth) calculated from the MASW (Multi-channel Analysis of Surface Wave) survey method, we develop a first-order site characterization map. Our results indicate that the terrain-based Vs30 estimates are significantly associated with amplitudes recorded at station sites. We also find that the damage distribution inferred from UNOSAT (UNITAR Operational Satellite Applications Program) data matches our estimates. However, the strongest amplifications are observed at two stations on a foothill ridge, where Vs30 values indicate that amplification should be relatively lower. Hough et al. (2010, this session) conclude that the observations can be explained by topographic amplification along a steep, narrow ridge. On the basis of these preliminary results, we conclude that the terrain-based framework, which characterizes topographic amplification as well as sediment-induced amplification, is needed to develop a microzonation map for Port-au-Prince.

Yong, A.; Hough, S. E.; Cox, B. R.; Rathje, E. M.; Bachhuber, J.; Hulslander, D.; Christiansen, L.; Abrams, M.

2010-12-01

279

Characterization of the Sediment Routing System of the Argentine Las Peñas Thrust From ASTER Imagery Interpretation and DEM Terrain Analysis  

NASA Astrophysics Data System (ADS)

In an arid region north of Mendoza, Argentina active structures of the Precordilleran fold and thrust belt control sedimentation in the proximal Andean foreland basin. Initiation of new thrust faults and along-strike growth of fault-propagation folds drives uplift of hanging-wall source areas. Drainage basin initiation and development in the Las Peñas thrust hanging-wall triggers erosion of sediment, controlling transport and depositional mechanisms in the associated alluvial fan system. Alluvial fans are classified as either sheetflood or debris-flow fans based on the areally dominant process responsible for producing the sediment wedge as recorded in the surface character and morphology of the fans. Traditionally, information about these systems has been directly measured using manual methods such as ground surveying and visible image interpretation. This study implements remote sensing with ASTER spectral data and derived topographic data to characterize both fan surfaces and drainage basins. AST14DMO data include fourteen ASTER Level-1B calibrated nadir looking radiance bands at 15-m (VNIR), 30-m (SWIR) and 90-m (TIR) resolution. AST14DMO also includes the ASTER 30-m Digital Elevation Model (DEM) derived from stereoscopic data from the VNIR sensor. These bands were used in rule-based classification implemented in statistical software. The classification was used for mapping and measuring the patterns and spectral characteristics of fan surfaces. TIR and VNIR explanatory variables in decision trees highlighted differences in fan environmental variables including soil conditions, sediment size, and vegetation (moisture, roughness, and composition) indicative of process and rate of deposition on alluvial fans. Terrain Analysis conducted with the ASTER 30-m DEM focused on morphology of the drainage basin sector of the sediment routing system. Drainage basin characteristics including areal extent, slope, aspect, hypsometric curves, and bedrock geology were identified and compared. The information was used to interpret transport and depositional mechanisms within the system, as well as identify source materials and possible ranges of fluid-sediment concentrations for each basin. The geometry of the developing Las Peñas thrust controls attributes of both drainage basin source areas, and alluvial fan depositional environments as shown by their variation along the fault. The techniques and setting of this study inform interpretations of processes active in modern systems that are applicable to ancient systems on Earth and elsewhere.

Abrahamson, I. S.; Schmitt, J.

2009-12-01

280

Developing sub 5-m LiDAR DEMs for forested sections of the Alpine and Hope faults, South Island, New Zealand: Implications for structural interpretations  

NASA Astrophysics Data System (ADS)

Kilometre-wide airborne light detection and ranging (LiDAR) surveys were collected along portions of the Alpine and Hope faults in New Zealand to assess the potential for generating sub 5-m bare earth digital elevation models (DEMs) from ground return data in areas of dense rainforest (bush) cover as an aid to mapping these faults. The 34-km long Franz-Whataroa LiDAR survey was flown along the densely-vegetated central-most portion of the transpressive Alpine Fault. Six closely spaced flight lines (200 m apart) yielded survey coverage with double overlap of swath collection, which was considered necessary due to the low density of ground returns (0.16 m-2 or a point every 6 m2) under mature West Coast podocarp-broadleaf rainforest. This average point spacing (˜2.5 m) allowed for the generation of a robust, high quality 3-m bare earth DEM. The DEM confirmed the zigzagged form of the surface trace of the Alpine Fault in this area, originally recognised by Norris and Cooper (1995, 1997) and highlights that the surface strike variations are more variant than previously mapped. The 29-km long Hurunui-Hope LiDAR survey was flown east of the Main Divide of the Southern Alps along the dextral-slip Hope Fault, where the terrain is characterised by lower rainfall and more open beech forest. Flight line spacings of ˜275 m were used to generate a DEM from the ground return data. The average ground return values under beech forest were 0.27 m-2 and yielded an estimated cell size suitable for a 2-m DEM. In both cases the LiDAR revealed unprecedented views of the surface geomorphology of these active faults. Lessons learned from our survey methodologies can be employed to plan cost-effective, high-gain airborne surveys to yield bare earth DEMs underneath vegetated terrain and multi-storeyed canopies from densely forested environments across New Zealand and worldwide.

Langridge, R. M.; Ries, W. F.; Farrier, T.; Barth, N. C.; Khajavi, N.; De Pascale, G. P.

2014-07-01

281

An iterative LiDAR DEM-aided algorithm for GNSS positioning in obstructed/rapidly undulating environments  

NASA Astrophysics Data System (ADS)

This paper describes a new algorithm to aid stand-alone GNSS positioning in areas of bad signal reception using a Digital Elevation Model (DEM). Traditional Height-Aiding (HA) algorithms assume either a preset (fixed) value for the receiver elevation or rely on the elevation value that corresponds to the nearest available position fix. This may lead in erroneous receiver elevation estimates that, under circumstances, are inefficient to aid effectively GNSS positioning. In this study, the receiver elevation is updated at every iteration step of the navigation solution through dynamic interpolation of the elevation model. The algorithm, because of its ability to extract and fully exploit the elevation information derived from a digital model, it can prove particularly useful in forested areas with steep-sloped terrain. Extended test runs were undertaken to validate the correctness of the mathematical model and the feasibility of the algorithm and associated software. Particularly, analysis of a dataset acquired in a forested, rapidly undulating environment reveals significant average improvement in all performance metrics of positioning, namely the GNSS position availability (50%), accuracy (56%) and external reliability (86%) compared to the Standard Point Positioning (SPP) solution. Moreover, it was found that the method can cope successfully in marginal operating conditions with situations of bad satellite geometry and satellite signals affected by interference due to tree canopy.

Danezis, Chris; Gikas, Vassilis

2013-09-01

282

Numerical Modelling of the Anisotropic Mechanical Behaviour of Opalinus Clay at the Laboratory-Scale Using FEM/DEM  

NASA Astrophysics Data System (ADS)

The Opalinus Clay (OPA) is an argillaceous rock formation selected to host a deep geologic repository for high-level nuclear waste in Switzerland. It has been shown that the excavation damaged zone (EDZ) in this formation is heavily affected by the anisotropic mechanical response of the material related to the presence of bedding planes. In this context, the purpose of this study is twofold: (i) to illustrate the new developments that have been introduced into the combined finite-discrete element method (FEM/DEM) to model layered materials and (ii) to demonstrate the effectiveness of this new modelling approach in simulating the short-term mechanical response of OPA at the laboratory-scale. A transversely isotropic elastic constitutive law is implemented to account for the anisotropic elastic modulus, while a procedure to incorporate a distribution of preferentially oriented defects is devised to capture the anisotropic strength. Laboratory results of indirect tensile tests and uniaxial compression tests are used to calibrate the numerical model. Emergent strength and deformation properties, together with the simulated damage mechanisms, are shown to be in strong agreement with experimental observations. Subsequently, the calibrated model is validated by investigating the effect of confinement and the influence of the loading angle with respect to the specimen anisotropy. Simulated fracture patterns are discussed in the context of the theory of brittle rock failure and analyzed with reference to the EDZ formation mechanisms observed at the Mont Terri Underground Research Laboratory.

Lisjak, Andrea; Tatone, Bryan S. A.; Grasselli, Giovanni; Vietor, Tim

2014-01-01

283

DEMS study of gas evolution at thick graphite electrodes for lithium-ion batteries: the effect of ?-butyrolactone  

NASA Astrophysics Data System (ADS)

Differential electrochemical mass spectrometry (DEMS) was used to study the reductive decomposition of an electrolyte based on ethylene carbonate/dimethyl carbonate (EC/DMC), as well as the formation of a solid electrolyte interphase (SEI) in this electrolyte, at thick (75-100 ?m) porous graphite composite electrodes. A number of graphite electrodes differing in their electrochemical lithium intercalation properties were investigated in potential-sweep experiments. They proved to be similar with respect to the evolution of ethylene and hydrogen gas during the first two charge/discharge cycles. Due to an incomplete coulombic conversion, a high irreversible capacity, as well as slow diffusion kinetics and an enhanced ohmic resistance of the electrodes, SEI formation on these thick electrodes was not yet complete after the first charge/discharge cycle. Undesired gas evolution can be reduced by adding ?-butyrolactone (GBL) as an electrolyte co-solvent. The amount of ethylene and hydrogen gas evolved decreases with increasing percentages of GBL in an EC/DMC electrolyte, indicating that the SEI layer is built up from GBL rather than from EC decomposition products.

Lanz, Martin; Novák, Petr

284

Slope Analysis of Scarps in Deuteronilus Mensae from Mola Data and Viking D.E.M: Evidence for Landslides Controlled by Ground Ice  

NASA Astrophysics Data System (ADS)

The surface of Mars is affected by a large variety of features related to ice like lobate debris aprons, softened craters or fretted channels. Many of these features are observed in the region of Deuteronilus Mensae where kilometer high scarps separate northern plains from southern highlands. The formation of lobate debris aprons at the foot of these scarps involves processes due to ice creep and mass wasting. The measurements of the volume of these debris aprons from new MOLA data (Mars Observer Laser Altimeter) conclude that only huge landslides can produce such volumes. The goal of this study is to test this result by the measurements of the slopes of scarps using both MOLA data and Digital Elevation Model (DEM) calculated from Viking images. It also point out that the combination between MOLA data and Viking DEM is very useful to measure steep slopes. Additional information can be found in the original extended abstract.

Mangold, N.; Baratoux, D.; Frey, V.

2000-08-01

285

19. Januar 2012 Die Zusammenarbeit zwischen der  

E-print Network

.: Extraktion und Bewertung von Merkmalen für die Klassifizie- rung von Farbbildern (Briefmarken) . . . . . . . . . . . . . . . . . . . . . . . . . . . 1996 Kock, A.: Automatische Beschreibung von Bauelementeanschlüssen . 2000 Nagel, A.: Konzeption für in Matrixcodes . . . . . . . . . . . 2002 Becker, B.: Automatische Erkennung von Verschmutzungen bei der Bildauf

Hochmuth, Olaff

286

c Lerche, Uni. Freiburg, 1 Statistik: Zwischen  

E-print Network

. Datenerhebung #12;c Lerche, Uni. Freiburg, 13 Strittige Sozialstatistiken I. Verbreitung der Prostitution um Prostitution um 1850 in New York a) Sch¨atzung des Bischofs der Methodistenkirche (1866): 11 000 ­ 12 000 b Sozialstatistiken I. Verbreitung der Prostitution um 1850 in New York a) Sch¨atzung des Bischofs der

Lerche, Hans Rudolf

287

c Lerche, Uni. Freiburg, 1 Statistik: Zwischen  

E-print Network

Sozialstatistiken I. Verbreitung der Prostitution um 1850 in New York a) Sch¨atzung des Bischofs der Sozialstatistiken I. Verbreitung der Prostitution um 1850 in New York a) Sch¨atzung des Bischofs der Lerche, Uni. Freiburg, 13 Strittige Sozialstatistiken I. Verbreitung der Prostitution um 1850 in New York

Lerche, Hans Rudolf

288

Bilder als Vermittler zwischen Krebsforschung und Mathematik  

E-print Network

& Motivation · Colorectal cancer is a frequent cancers which ranks high in mortality. · The majority of cancers Zellzyklen Unregelmäßige Zellphasen Mitogens Growth factors Receptorreceptor Ras Raf P P P P MEK P The ERK pathway is hyper-active in ca. 30% of all human tumours . MEK ERK P P cytoplasmic substrates Elk SAP Gene

Rostock, Universität

289

Effect of DEM resolution on rainfall-triggered landslide modeling within a triangulated network-based model. A case study in the Luquillo Forest, Puerto Rico  

NASA Astrophysics Data System (ADS)

Catchment slope distribution is one of the topographic characteristics that significantly control rainfall-triggered landslide modeling, in both direct and indirect ways. Slope directly determines the soil volume associated with instability. Indirectly slope also affects the subsurface lateral redistribution of soil moisture across the basin, which in turn determines the water pore pressure conditions that impact slope stability. In this study, we investigate the influence of DEM resolution on slope stability and the slope stability analysis by using a distributed eco-hydrological and landslide model, the tRIBS-VEGGIE (Triangulated Irregular Network (TIN)-based Real-time Integrated Basin Simulator - VEGetation Generator for Interactive Evolution). The model implements a triangulated irregular network to describe the topography, and it is capable of evaluating vegetation dynamics and predicting shallow landslides triggered by rainfall. The impact of DEM resolution on the landslide prediction was studied using five TINs derived from five grid DEMs at different resolutions, i.e. 10, 20, 30, 50 and 70 m respectively. The analysis was carried out on the Mameyes Basin, located in the Luquillo Experimental Forest in Puerto Rico, where previous landslide analyses have been carried out. Results showed that the use of the irregular mesh reduced the loss of accuracy in the derived slope distribution when coarser resolutions were used. The impact of the different resolutions on soil moisture patterns was important only when the lateral redistribution was considerable, depending on hydrological properties and rainfall forcing. In some cases, the use of different DEM resolutions did not significantly affect tRIBS-VEGGIE landslide output, in terms of landslide locations, and values of slope and soil moisture at failure.

Arnone, E.; Dialynas, Y. G.; Noto, L. V.; Bras, R. L.

2013-12-01

290

,Mega London` bezeichnet erstens das Entwurfsthema fr ein Gebude, in dem zwei Nutzungsprogramme hnlicher Gre Platz finden ein Megastore fr Sportartikel und ein Fitnesscenter fr Sportbegeisterte. ,Mega London` charakterisiert zweitens die Stand-ortwahl d  

E-print Network

,Mega London` bezeichnet erstens das Entwurfsthema für ein Gebäude, in dem zwei Nutzungsprogramme. ,Mega London` charakterisiert zweitens die Stand- ortwahl ­ das Projektgebiet ,Royal Albert Dock` ist ein wichtiger Entwicklungsbereich im Londoner Osten. Der hier betrachtete Bereich zeigt die

Berlin,Technische Universität

291

Mapping SOC content and bulk density of a disturbed peatland relict with electromagnetic induction and DEM data  

NASA Astrophysics Data System (ADS)

Peatlands represent a huge storage of soil organic carbon (SOC), and there is considerable interest to assess the total amount of carbon stored in these ecosystems. However, reliable field-scale information about peat properties, particularly SOC content and bulk density (BD) necessary to estimate C stocks, remains difficult to obtain. A potential way to acquire information on these properties and its spatial variation is the non-invasive mapping of easily recordable physical variables that correlate with peat properties, such as bulk electrical conductivity (ECa) measured with electromagnetic induction (EMI). However, ECa depends on a range of soil properties, including BD, soil and water chemistry, and water content, and thus results often show complex and site-specific relationships. Therefore, a reliable prediction of SOC and BD from ECa data is not necessarily given. In this study, we aim to explore the usefulness of Multiple Linear Regression (MLR) models to predict the peat soil properties SOC and BD from multi-offset EMI and high-resolution DEM data. The quality of the MLR models is assessed by cross-validation. We use data from a medium-scale disturbed peat relict (approximately 35ha) in Northern Germany. The potential explanatory variables considered in MLR were: EMI data of six different integral depths (approximately 0.25, 0.5, 0.6, 0.9, 1, and 1.80 m), their vertical heterogeneity, as well as several topographical variables extracted from the DEM. Ground truth information for SOC, BD content and peat layer thickness was obtained from 34 soil cores of 1 m depth. Each core was divided into several 5 to 20 cm thick layers so that integral information of the upper 0.25, 0.5, and 1 m as well as from the total peat layer was obtained. For cross-validation of results, we clustered the 34 soil cores into 4 classes using K-means clustering and selected 8 cores for validation from the clusters with a probability that depended on the size of the cluster. With the remaining 26 samples, we performed a stepwise MLR and generated separate models for each depth and soil property. Preliminary results indicate reliable model predictions for SOC and BD (R² = 0.83- 0.95). The RMSE values of the validation ranged between 3.5 and 7.2 vol. % for SOC and 0.13 and 0.37 g/cm³ for BD for the independent samples. This equates roughly the quality of SOC predictions obtained by field application of vis-NIR (visible-near infrared) presented in literature for a similar peatland setting. However, the EMI approach offers the potential to derive information from deeper depths and allows non-invasive mapping of BD variability, which is not possible with vis-NIR. Therefore, this new approach potentially provides a more useful tool for total carbon stock assessment in peatlands.

Altdorff, Daniel; Bechtold, Michel; van der Kruk, Jan; Tiemeyer, Bärbel; von Hebel, Christian; Huisman, Johan Alexander

2014-05-01

292

DEMS 4th period  

NSDL National Science Digital Library

Today, you are going to practice finding multiples and adding fractions! FIRST, you will practice finding multiples with the Mayor of Pumpkinville. You will START with finding multiples of 2. THEN, you will find multiples of 3 through 12. Once you have TEN multiples of EACH number, you may move to the next game! GOOD LUCK! CLICK HERE -->Pumpkin Multiples Once you have ...

Ms. Smith

2009-02-14

293

InSAR techniques for reliable deformation estimation in volcanic areas and a first glance of Tandem-DEM accuracy - test site El Hierro Island  

NASA Astrophysics Data System (ADS)

The accuracy and availability of deformation measurements using InSAR techniques is limited due to decorrelation effects, atmospheric disturbances and the SAR side-looking geometry (layover and shadowing). In this talk, we present our recent research and achievements on advanced InSAR techniques in order to retrieve reliable deformation signals from active volcanoes using high resolution TerraSAR-X (TSX) images. Another highlight of this talk is the evaluation of an experimental TanDEM-X (TDX) RawDEM with a resolution of approximately 6 m in order to compensate the topographic phase. A volcanic test site which is currently highly active -El Hierro- has been selected to demonstrate the developed techniques: 1) PSI processing in volcanic areas using high resolution TSX images; 2) Mitigation of atmospheric delay distortions; 3) Fusion of multi-geometrical PSI clouds. In order to measure the deformation from 2011 to 2013 at El Hierro [1], two stacks of stripmap TSX Mission data have been acquired, one in ascending orbit and one in descending. Each stack has more than 25 scenes. More than 1.5 million PSs have been detected (SCR>3.0 dB). The stratified atmospheric delay for each acquisition has been integrated for the PSI reference network and, afterwards, interpolated and compensated for all PSs. A linear deformation model has been assumed for PSI processing. For the descending orbit stack, a relative deformation from -21.7 to 131.8 mm/y from Sep. 2011 to Jan. 2013 with respect to a reference point located on the northeast coast has been measured. On the one hand, the spatial variation of the deformation has a good agreement with the seismicity distribution [1]. On the other hand, the deformation magnitude agrees with in-situ GPS measurements [2]. In ascending orbit, the linear deformation rate varies from -22.8 to 90.9 mm/y. This different range of value is due to a scene acquired on Feb. 2010, which has been included in order to obtain the pre-seismic deformation signal. Comparing the results before and after stratified atmospheric delay compensation, the atmospheric induced deformation is correlated with height, but not linear. The deformation error induced by atmosphere has an absolute impact of more than 10 mm/y in this case. In topography, the maximum error is up to10 m. A TDX-RawDEM has been used for topographic phase removal. A significant improvement in single differential interferograms has been observed when compared to SRTM-DEM based topography removal. The topographic updates of the RawDEM are located mostly in urban areas and in vegetated areas. Most of height differences are located in a range between -5 and 5 m, except for layover and shadowing areas. In this case, the standard deviation of the uncalibrated RawDEM height noise is better 2.5 m both in ascending orbit and in descending orbit. [1] Lopez, C., et al. (2012), Monitoring the volcanic unrest of El Hierro (Canary Islands) before the onset of the 2011-2012 submarine eruption, Geophys. Res. Lett. [2] GPS Deformation: www.seis.nagoya-u.ac.jp/sagiya/Sagiyas_Page/Canary.html

Cong, X.; Eineder, M.; Fritz, T.

2013-12-01

294

Intercomparison of DEM-based approaches for the identification of flood-prone areas in different geomorphologic and climatic conditions  

NASA Astrophysics Data System (ADS)

Floods represent the most critical natural hazard for many countries and their frequency appears to be increasing in recent times. The legal constraints of public administrators and the growing interest of private companies (e.g., insurance companies) in identifying the areas exposed to the flood risk, is determining the necessity of developing new tools for the risk classification over large areas. Nowadays, among the numerous hydrologic and hydraulic methods regularly used for practical applications, 2-D hydraulic modeling represents the most accurate approach for deriving detailed inundation maps. Nevertheless, data requirement for these modeling approaches is certainly onerous, limiting their applicability over large areas. On this issue, the terrain morphology may provide an extraordinary amount of information useful to detect areas that are particularly prone to serious flooding. In the present work, we compare the reliability of different DEM-derived quantitative morphologic descriptors in characterizing the relationships between geomorphic attributes and flood exposure. The tests are carried out using techniques of pattern classification, such as linear binary classifiers (Degiorgis et al., 2012), whose ability is evaluated through performance measures. Simple and composed morphologic features are taken into account. The morphological features are: the upslope contributing area (A), the local slope (S), the length of the path that hydrologically connects the location under exam to the nearest element of the drainage network (D), the difference in elevation between the cell under exam and the final point of the same path (H), the curvature (downtriangle2H). In addition to the mentioned features, the study takes into consideration a number of composed indices, such as: the modified topographic index (Manfreda et al., 2011), the downslope index (DI) proposed by Hjerdt et al. (2004), the ratio between the elevation difference H and the distance to the network D, and other indices. Each binary classifier is applied in several catchments in order to verify the reproducibility of the procedures in different geomorphologic, climatic and hydrologic conditions. The study explores the use of these procedures in gauged river basins located in Italy and in an ungauged basin located in Africa. References Degiorgis, M., G. Gnecco, S. Gorni, G. Roth, M. Sanguineti, A.C. Taramasso, 2012. Classifiers for the detection of flood-prone areas using remote sensed elevation data, J. Hydrol., 470-471, 302-315. Hjerdt, K. N., J.J. McDonnell, J. Seibert, A. Rodhe, A new topographic index to quantify downslope controls on local drainage, Water Resour. Res., 40, W05602, 2004. Manfreda, S., M. Di Leo, A. Sole, Detection of Flood Prone Areas using Digital Elevation Models, J. Hydrol. Eng., 16(10), 781-790, 2011.

Samela, Caterina; Nardi, Fernando; Grimaldi, Salvatore; De Paola, Francesco; Sole, Aurelia; Manfreda, Salvatore

2014-05-01

295

Study of Morphologic Change in Poyang Lake Basin Caused by Sand Dredging Using Multi-temporal Landsat Images and DEMs  

NASA Astrophysics Data System (ADS)

Sand dredging has been practiced in rivers, lakes, harbours and coastal areas in recent years in China mostly because of demand from construction industry as building material. Sand dredging has disturbed aquatic ecosystems by affecting hydrological processes, increasing content of suspended sediments and reducing water clarity. Poyang Lake, connecting with Yangtze River in the lower reaches of the Yangtze River, is the largest fresh water lake in China. Sand dredging in Poyang Lake has been intensified since 2001 because such practice was banned in Yangtze River and profitable. In this study, the morphologic change caused by sand dredging in Poyang Lake basin was analysed by overlaying two DEMs acquired in 1952 and 2010 respectively. Since the reflectance of middle infrared band for sand dredging vessel is much higher than that of water surface, sand dredging vessels were showed as isolated grey points and can be counted in the middle infrared band in 12 Landsat images acquired in flooding season during 2000~2010. Another two Landsat images (with low water level before 2000 and after 2010) were used to evaluate the morphologic change by comparing inundation extent and shoreline shape. The following results was obtained: (1) vessels for sand dredging are mainly distributed in the north of Poyang Lake before 2007, but the dredging area was enlarged to the central region and even to Gan River; (2) sand dredging area reached to about 260.4 km2 and is mainly distributed in the north of Songmen Mountain and has been enlarged to central of Poyang Lake from the distribution of sand vessels since 2007. Sand dredged from Poyang Lake was about 1.99 × 109 m3 or 2448 Mt assuming sediment bulk density of 1.23 t m-3. It means that the magnitude of sand mining during 2001-2010 is almost ten times of sand depositions in Poyang Lake during 1955-2010; (3) Sand dredging in Poyang Lake has alternated the lake capacity and discharge section area, some of the watercourse in the northern channel was enlarged by more than 1 km when in low lake level. This study is useful to understand the change of hydrological system, especially the drying up trend in Poyang Lake in recent autumns and winters.

Qi, S.; Zhang, X.; Wang, D.; Zhu, J.; Fang, C.

2014-11-01

296

Tracking and evolution of irrigation triggered active landslides by multi-source high resolution DEM: The Jiaojiacun landslide group of Heifangtai (Northwest of China)  

NASA Astrophysics Data System (ADS)

The construction of three large hydropower stations, i.e. Liujia, Yanguo and Bapan, resulted in the immigration of the impacted people to Heifangtai from 1960s. To support the living and farming of the immigrated people, a large amount of water has been pumped from the Yellow River to Heifangtai, which has changed the former underground water budget and led to 111 landslides from 1968 in this area. To reveal the deformation process of landslides in Heifangtai, a quantitative deformation analysis model of landslide based on multi-source DEM data is established using four periods of topographic maps obtained in 1970, 2001, 2010 and 2013 respectively, including two 1:10000 topographic maps and two 1:1000 data acquired from 3D Laser Scanner. The whole study area was divided into two sections based on the two distinct kinds of landslide patterns. The selected morphometric parameters, residual topographic surface and surface roughness, extracted from three typical landslides, and the statistical analysis (Box-plot diagrams) of the temporal variations of these parameters, allowed the reconstruction and tracking of these landslides. We monitored the changing of landslide boundaries, average vertical and horizontal displacement rates and zones of uplift and subsidence. The volumes of removed and/or accumulated material were estimated as well. We can then demonstrate the kinematics of landslides based on information from high-resolution DEM, and the changing table of underground water, ring-shear test and soil-water characteristic curve referenced from other researchers. The results provide a new insight on the use of multi-source high resolution DEM in the monitoring of irrigation-triggered landslides.

Zeng, Runqiang; Meng, Xingmin; Wang, Siyuan; Chen, Guan; Lee, Yajun; Zhang, Yi

2014-05-01

297

The Multi-Instrument (EVE-RHESSI) DEM for Solar Flares, and Implications for Residual Non-Thermal Soft X-Ray Emission  

NASA Astrophysics Data System (ADS)

In the soft X-ray energy range, solar flare spectra are typically dominated by thermal emission. The low energy extent of non-thermal emission can only be loosely quantified using currently available X-ray data. To address this issue, we combine observations from the EUV Variability Experiment (EVE) on-board the Solar Dynamics Observatory (SDO) with X-ray data from the Reuven Ramaty High Energy Spectroscopic Imager (RHESSI). The improvement over the isothermal approximation is intended to resolve the ambiguity in the range where the thermal and non-thermal components may have similar photon fluxes. This "crossover" range can extend up to 30 keV for medium to large solar flares.Previous work (Caspi et.al. 2014ApJ...788L..31C) has concentrated on obtaining DEM models that fit both instruments' observations well. Now we are interested in any breaks and cutoffs in the "residual" non-thermal spectrum; i.e., the RHESSI spectrum that is left over after the DEM has accounted for the bulk of the soft X-ray emission. Thermal emission is again modeled using a DEM that is parametrized as multiple gaussians in temperature; the non-thermal emission is modeled as a photon spectrum obtained using a thin-target emission model ('thin2' from the SolarSoft Xray IDL package). Spectra for both instruments are fit simultaneously in a self-consistent manner. The results for non-thermal parameters then are compared with those found using RHESSI data alone, with isothermal and double-thermal models.

McTiernan, James M.; Caspi, Amir; Warren, Harry

2015-04-01

298

Seasonal variabilty of surface velocities and ice discharge of Columbia Glacier, Alaska using high-resolution TanDEM-X satellite time series and NASA IceBridge data  

NASA Astrophysics Data System (ADS)

Columbia Glacier is a grounded tidewater glacier located on the south coast of Alaska. It has lost half of its volume during 1957-2007, more rapidly after 1980. It is now split into two branches, known as Main/East and West branch due to the dramatic retreat of ~ 23 km and calving of iceberg from its terminus in past few decades. In Alaska, a majority of the mass loss from glaciers is due to rapid ice flow and calving icebergs into tidewater and lacustrine environments. In addition, submarine melting and change in the frontal position can accelerate the ice flow and calving rate. We use time series of high-resolution TanDEM-X stripmap satellite imagery during 2011-2013. The active image of the bistatic TanDEM-X acquisitions, acquired over 11 or 22 day repeat intervals, are utilized to derive surface velocity fields using SAR intensity offset tracking. Due to the short temporal baselines, the precise orbit control and the high-resolution of the data, the accuracies of the velocity products are high. We observe a pronounce seasonal signal in flow velocities close to the glacier front of East/Main branch of Columbia Glacier. Maximum values at the glacier front reach up to 14 m/day were recorded in May 2012 and 12 m/day in June 2013. Minimum velocities at the glacier front are generally observed in September and October with lowest values below 2 m/day in October 2012. Months in between those dates show corresponding increase or deceleration resulting a kind of sinusoidal annual course of the surface velocity at the glacier front. The seasonal signal is consistently decreasing with the distance from the glacier front. At a distance of 17.5 km from the ice front, velocities are reduced to 2 m/day and almost no seasonal variability can be observed. We attribute these temporal and spatial variability to changes in the basal hydrology and lubrification of the glacier bed. Closure of the basal drainage system in early winter leads to maximum speeds while during a fully developed basal drainage system speeds are at their minimum. We also analyze the variation in conjunction with the prevailing meteorological conditions as well as changes in calving front position in order to exclude other potential influencing factors. In a second step, we also exploit TanDEM-X data to generate various digital elevation models (DEMs) at different time steps. The multi-temporal DEMs are used to estimate the difference in surface elevation and respective ice thickness changes. All TanDEM-X DEMs are well tied with a SPOT reference DEM. Errors are estimated over ice free moraines and rocky areas. The quality of the TanDEM-X DEMs on snow and ice covered areas are further assessed by a comparison to laser scanning data from NASA Icebridge campaigns. The time wise closest TanDEM-X DEMs were compared to the Icebridge tracks from winter and summer surveys in order to judge errors resulting from the radar penetration of the x/band radar signal into snow, ice and firn. The average differences between laser scanning and TanDEM-X in August, 2011 and March, 2012 are observed to be 8.48 m and 14.35 m respectively. Retreat rates of the glacier front are derived manually by digitizing the terminus position. By combining the data sets of ice velocity, ice thickness and the retreat rates at different time steps, we estimate the seasonal variability of the ice discharge of Columbia Glacier.

Vijay, Saurabh; Braun, Matthias

2014-05-01

299

An integrated Quality by Design (QbD) approach towards design space definition of a blending unit operation by Discrete Element Method (DEM) simulation.  

PubMed

A combined Quality by Design (QbD) and Discrete Element Model (DEM) simulation-approach is presented to characterize a blending unit operation by evaluating the impact of formulation parameters and process variables on the blending quality and blending end point. Understanding the variability of both the API and the excipients, as well as their impact on the blending process are critical elements for blending QbD. In a first step, the QbD-methodology is systematically used to (1) establish the critical quality attribute content uniformity and to link this CQA to its surrogate blend homogeneity, (2) identify potentially critical input factors that may affect blending operation quality and (3) risk-rank these factors to define activities for process characterization. Subsequently, a DEM-simulation-based characterization of the blending process is performed. A statistical evaluation is finally presented, relating blend homogeneity of systems with low particle number to the regulatory requirements. Data are then used to map out a three-dimensional knowledge space, providing parameters to define a design space and set up an appropriate control strategy. PMID:21056102

Adam, Siegfried; Suzzi, Daniele; Radeke, Charles; Khinast, Johannes G

2011-01-18

300

Application of the inundation area—lake level rating curves constructed from the SRTM DEM to retrieving lake levels from satellite measured inundation areas  

NASA Astrophysics Data System (ADS)

Remote sensing technology has great potential for measuring lake inundation areas and lake levels, and providing important lake water quantity and quality information which can be used for improving our understanding of climate change impacts on the global water cycle, and assessing the influence of the projected future climate change on the global water resources. One remote sensing approach is to estimate lake level from satellite measured inundation area based on the inundation area—lake level rating (IALLR) curves. However, this approach is not easy to implement because of a lack of data for constructing the IALLR curves. In this study, an innovative and robust approach to construct the IALLR curves from the digital elevation model (DEM) data collected during the Shuttle Radar Topography Mission (SRTM) was developed and tested. It was shown that the IALLR curves derived from the SRTM DEM data could be used to retrieve lake level from satellite measured inundation area. Applying the constructed IALLR curve to the estimated inundation areas from 16 Landsat Thematic Mapper (TM) images, 16 lake levels of Lake Champlain in Vermont were obtained. The root mean square error (RMSE) of the estimated lake levels compared to the observed water levels at the U.S. Geological Survey (USGS) gauging station (04294500) at Burlington, Vermont is about 0.12 m.

Pan, Feifei; Liao, Jingjuan; Li, Xinwu; Guo, Huadong

2013-03-01

301

GPS radio occultation with TerraSAR-X and TanDEM-X: sensitivity of lower troposphere sounding to the Open-Loop Doppler model  

NASA Astrophysics Data System (ADS)

The Global Positioning System (GPS) radio occultation (RO) technique provides valuable input for numerical weather prediction and is considered as a data source for climate related research. Numerous studies outline the high precision and accuracy of RO atmospheric soundings in the upper troposphere and lower stratosphere. In this altitude region (8-25 km) RO atmospheric soundings are considered to be free of any systematic error. In the tropical (30° S-30° N) Lower (<8 km) Troposphere (LT), this is not the case; systematic differences with respect to independent data sources exist and are still not completely understood. To date only little attention has been paid to the Open Loop (OL) Doppler model. Here we report on a RO experiment carried out on-board of the twin satellite configuration TerraSAR-X and TanDEM-X which possibly explains to some extent biases in the tropical LT. In two sessions we altered the OL Doppler model aboard TanDEM-X by not more than ±5 Hz with respect to TerraSAR-X and compare collocated atmospheric refractivity profiles. We find a systematic difference in the retrieved refractivity. The bias mainly stems from the tropical LT; there the bias reaches up to ±1%. Hence, we conclude that the negative bias (several Hz) of the OL Doppler model aboard TerraSAR-X introduces a negative bias (in addition to the negative bias which is primarily caused by critical refraction) in our retrieved refractivity in the tropical LT.

Zus, F.; Beyerle, G.; Heise, S.; Schmidt, T.; Wickert, J.

2014-12-01

302

Uplift mechanism for a shallow-buried structure in liquefiable sand subjected to seismic load: centrifuge model test and DEM modeling  

NASA Astrophysics Data System (ADS)

Based on a centrifuge model test and distinct element method (DEM), this study provides new insights into the uplift response of a shallow-buried structure and the liquefaction mechanism for saturated sand around the structure under seismic action. In the centrifuge test, a high-speed microscopic camera was installed in the structure model, by which the movements of particles around the structure were monitored. Then, a two-dimensional digital image processing technology was used to analyze the microstructure of saturated sand during the shaking event. Herein, a numerical simulation of the centrifuge experiment was conducted using a two-phase (solid and fluid) fully coupled distinct element code. This code incorporates a particle-fluid coupling model by means of a "fixed coarse-grid" fluid scheme in PFC3D (Particle Flow Code in Three Dimensions), with the modeling parameters partially calibrated based on earlier studies. The physical and numerical models both indicate the uplifts of the shallow-buried structure and the sharp rise in excess pore pressure. The corresponding micro-scale responses and explanations are provided. Overall, the uplift response of an underground structure and the occurrence of liquefaction in saturated sand are predicted successfully by DEM modeling. However, the dynamic responses during the shaking cannot be modeled accurately due to the restricted computer power.

Zhou, Jian; Wang, Zihan; Chen, Xiaoliang; Zhang, Jiao

2014-06-01

303

A new set of MATLAB functions (TecDEM toolbox) to analyze erosional stages in landscapes and base-level changes in river profiles  

NASA Astrophysics Data System (ADS)

We implemented three new functions in the MATLAB-based TecDEM toolbox [1,2]: surface index, topographic position index, and the analysis of base-levels in river longitudinal profiles. These tools provide useful ways to understand the effects of base-level changes on topography such as stream captures, erosion or rejuvenation of pre-existing topographic features and anomalies in river longitudinal profiles. We developed a new index (referred as "surface index") which provides a quick way to map simultaneously preserved and eroded portions of an elevated landscape. This index classifies landscapes according to their erosional stages using the combination of the hypsometric integral, which efficiently highlights flat surfaces, and the surface roughness, which substantially increases with incision. We also implemented the commonly used "topographic position index". This index provides a simple way to classify the landscapes as valleys, ridges and flat areas. However, its application in tectonic geomorphology can go far beyond as it discriminates valleys shapes and reveals other important features such as wind gaps and knickpoints when associated to the extracted river system. Finally, we implemented a tool allowing the estimation of base-level changes using the reconstruction of river longitudinal profiles. River profiles can be decomposed in concave or convex segments. Relict base-levels are typically associated to gently concave segments in river profiles. By restoring the initial shape of these segments we are able to estimate the amount of incision between the present day base-level and the relict base-level. All these tools were successfully tested in different settings such as Central America, Central Europe and Pamir. In addition to the description of these tools we provide examples from these different areas. [1] Shahzad, F., & Gloaguen, R. (2011). TecDEM: A MATLAB based toolbox for tectonic geomorphology, Part 1: Drainage network preprocessing and stream profile analysis. Computers & Geosciences, 37, 250-260. [2] Shahzad, F., & Gloaguen, R. (2011). TecDEM: A MATLAB based toolbox for tectonic geomorphology, Part 2: Surface dynamics and basin analysis. Computers & Geosciences, 37, 261-271.

Andreani, Louis; Gloaguen, Richard; Shahzad, Faisal

2014-05-01

304

Full-waveform and discrete-return lidar in salt marsh environments: An assessment of biophysical parameters, vertical uncertatinty, and nonparametric dem correction  

NASA Astrophysics Data System (ADS)

High-resolution and high-accuracy elevation data sets of coastal salt marsh environments are necessary to support restoration and other management initiatives, such as adaptation to sea level rise. Lidar (light detection and ranging) data may serve this need by enabling efficient acquisition of detailed elevation data from an airborne platform. However, previous research has revealed that lidar data tend to have lower vertical accuracy (i.e., greater uncertainty) in salt marshes than in other environments. The increase in vertical uncertainty in lidar data of salt marshes can be attributed primarily to low, dense-growing salt marsh vegetation. Unfortunately, this increased vertical uncertainty often renders lidar-derived digital elevation models (DEM) ineffective for analysis of topographic features controlling tidal inundation frequency and ecology. This study aims to address these challenges by providing a detailed assessment of the factors influencing lidar-derived elevation uncertainty in marshes. The information gained from this assessment is then used to: 1) test the ability to predict marsh vegetation biophysical parameters from lidar-derived metrics, and 2) develop a method for improving salt marsh DEM accuracy. Discrete-return and full-waveform lidar, along with RTK GNSS (Real-time Kinematic Global Navigation Satellite System) reference data, were acquired for four salt marsh systems characterized by four major taxa (Spartina alterniflora, Spartina patens, Distichlis spicata, and Salicornia spp.) on Cape Cod, Massachusetts. These data were used to: 1) develop an innovative combination of full-waveform lidar and field methods to assess the vertical distribution of aboveground biomass as well as its light blocking properties; 2) investigate lidar elevation bias and standard deviation using varying interpolation and filtering methods; 3) evaluate the effects of seasonality (temporal differences between peak growth and senescent conditions) using lidar data flown in summer and spring; 4) create new products, called Relative Uncertainty Surfaces (RUS), from lidar waveform-derived metrics and determine their utility; and 5) develop and test five nonparametric regression model algorithms (MARS -- Multivariate Adaptive Regression, CART -- Classification and Regression Trees, TreeNet, Random Forests, and GPSM -- Generalized Path Seeker) with 13 predictor variables derived from both discrete and full waveform lidar sources in order to develop a method of improving lidar DEM quality. Results of this study indicate strong correlations for Spartina alterniflora (r > 0.9) between vertical biomass (VB), the distribution of vegetation biomass by height, and vertical obscuration (VO), the measure of the vertical distribution of the ratio of vegetation to airspace. It was determined that simple, feature-based lidar waveform metrics, such as waveform width, can provide new information to estimate salt marsh vegetation biophysical parameters such as vegetation height. The results also clearly illustrate the importance of seasonality, species, and lidar interpolation and filtering methods on elevation uncertainty in salt marshes. Relative uncertainty surfaces generated from lidar waveform features were determined useful in qualitative/visual assessment of lidar elevation uncertainty and correlate well with vegetation height and presence of Spartina alterniflora. Finally, DEMs generated using full-waveform predictor models produced corrections (compared to ground based RTK GNSS elevations) with R2 values of up to 0.98 and slopes within 4% of a perfect 1:1 correlation. The findings from this research have strong potential to advance tidal marsh mapping, research and management initiatives.

Rogers, Jeffrey N.

305

Development of Flood Inundation Libraries using Historical Satellite Data and DEM for Part of Godavari Basin: An Approach Towards Better Flood Management  

NASA Astrophysics Data System (ADS)

Conventional method of identifying areas to be inundated for issuing flood alert require inputs like discharge data, fine resolution digital elevation model (DEM), software for modelling and technically trained manpower to interpret the results meaningfully. Due to poor availability of these inputs, including good network of historical hydrological observations and limitation of time, quick flood early warning becomes a difficult task. Presently, based on the daily river water level and forecasted water level for major river systems in India, flood alerts are provided which are non-spatial in nature and does not help in understanding the inundation (spatial dimension) which may be caused at various water levels. In the present paper a concept for developing a series of flood-inundation map libraries two approaches are adopted one by correlating inundation extent derived from historical satellite data analysis with the corresponding water level recorded by the gauge station and the other simulation of inundation using digital elevation model (DEM's) is demonstrated for a part of Godavari Basin. The approach explained can be one of quick and cost-effective method for building a library of flood inundation extents, which can be utilized during flood disaster for alerting population and taking the relief and rescue operations. This layer can be visualized from a spatial dimension together with other spatial information like administrative boundaries, transport network, land use and land cover, digital elevation data and satellite images for better understanding and visualization of areas to be inundated spatially on free web based earth visualization portals like ISRO's Bhuvan portal (http://bhuvan.nrsc.gov.in). This can help decision makers in taking quick appropriate measures for warning, planning relief and rescue operations for the population to get affected under that river stage.

Bhatt, C. M.; Rao, G. S.; Patro, B.

2014-12-01

306

Analysis of aromatic catabolic pathways in Pseudomonas putida KT 2440 using a combined proteomic approach: 2-DE/MS and cleavable isotope-coded affinity tag analysis.  

PubMed

Proteomic analysis of Pseudomonas putida KT2440 cultured in monocyclic aromatic compounds was performed using 2-DE/MS and cleavable isotope-coded affinity tag (ICAT) to determine whether proteins involved in aromatic compound degradation pathways were altered as predicted by genomic analysis (Jiménez et al., Environ Microbiol. 2002, 4, 824-841). Eighty unique proteins were identified by 2-DE/MS or MS/MS analysis from P. putida KT2440 cultured in the presence of six different organic compounds. Benzoate dioxygenase (BenA, BenD) and catechol 1,2-dioxygenase (CatA) were induced by benzoate. Protocatechuate 3,4-dixoygenase (PcaGH) was induced by p-hydroxybenzoate and vanilline. beta-Ketoadipyl CoA thiolase (PcaF) and 3-oxoadipate enol-lactone hydrolase (PcaD) were induced by benzoate, p-hydroxybenzoate and vanilline, suggesting that benzoate, p-hydroxybenzoate and vanilline were degraded by different dioxygenases and then converged in the same beta-ketoadipate degradation pathway. An additional 110 proteins, including 19 proteins from 2-DE analysis, were identified by cleavable ICAT analysis for benzoate-induced proteomes, which complemented the 2-DE results. Phenylethylamine exposure induced beta-ketoacyl CoA thiolase (PhaD) and ring-opening enzyme (PhaL), both enzymes of the phenylacetate (pha) biodegradation pathway. Phenylalanine induced 4-hydroxyphenyl-pyruvate dioxygenase (Hpd) and homogentisate 1,2-dioxygenase (HmgA), key enzymes in the homogentisate degradation pathway. Alkyl hydroperoxide reductase (AphC) was induced under all aromatic compounds conditions. These results suggest that proteome analysis complements and supports predictive information obtained by genomic sequence analysis. PMID:16470664

Kim, Young Hwan; Cho, Kun; Yun, Sung-Ho; Kim, Jin Young; Kwon, Kyung-Hoon; Yoo, Jong Shin; Kim, Seung Il

2006-02-01

307

Studien über Reflexe und Rhythmen beim Goldfisch (Carassius auratus)  

Microsoft Academic Search

Die Haut des Goldfisches besitzt eine hohe Empfindlichkeit gegen Wasserströmung. Nach Rückenmarkdurchschneidung in der Gegend zwischen dem 16. und dem 6. letzten Wirbel ist die Reizbarkeit dieses „Hautstromsinnes“ im Hintertier oft höher als die des intakten Seitenliniensystems im gleichen Vordertier. Der Hautsinn wird nur durch rasche Stromstöße erregt; gleichmäßige, beliebig hoch anschwellende Stromreize bleiben unbeantwortet. (Also keine „Rheotaxis“ mit Hilfe

Erich Holst

1934-01-01

308

WEST COAST DIGITAL ELEVATION MODELSCoastal Models Supporting our Nation's Needs through Science and Technology All of the coastal digital elevation models (DEMs) in this presentation were created by scientists  

E-print Network

and Technology #12;#12;All of the coastal digital elevation models (DEMs) in this presentation were created boasts many attractions such as the Puget Sound, the Pacific Coast Highway, the Redwood National Forest, are vulnerable to tsunamis, coastal storms, and other inundation events. Active plate boundaries and tectonic

309

Zu alt für einen Wechsel? Zum Zusammenhang von Alter, Lohndifferentialen und betrieblicher Mobilität  

Microsoft Academic Search

Due to the well known fact of a reduced mobility of older employees the workforce aging will have strong consequences for job mobility in Germany. On the basis of the IAB-Beschäftigtenstichprobe (IABS) the subsequent article analyzes the impact of age on (inter-firm) job mobility. In particular the study answers the question, how wage differentials of a potential job change evolve

Lutz Schneider

2007-01-01

310

Kanban - der Weg ist das Ziel  

NASA Astrophysics Data System (ADS)

Wenn man aktuell Produktionsbereiche in Deutschland und Europa besucht, fallen im Zusammenhang mit modernen Produktionsmethoden immer öfter die Begriffe Kanban (jap. Karte, Signal) und Pull-Produktion, und dies nicht ohne Stolz, da diese mit dem schillernden Vorbild des Toyota Produktionssystems in Zusammenhang stehen. Tatsächlich ist Kanban ein integraler Bestandteil moderner Produktionssysteme. Blickt man aber im Rahmen von Prozessanalysen hinter die Fassaden", d. h. in die tägliche Praxis der Arbeitsprozesse, wird man schnell desillusioniert - die viel gepriesenen klassischen Kanban-Regeln werden im Tagesgeschäft nicht eingehalten.

Aull, Florian; Berlak, Joachim; Dickmann, Eva; Dickmann, Philipp; Fischäder, Holm; Gerlach, Joachim; Henneberg, Jens; Kapalla, Klaus; Kress, Oliver; Kuttler, Robert; Schneider, Herfried M.; Schürle, Philipp; Stellpflug, Franz-Josef; Wannenwetsch, Ralph; Wulz, Johannes; Zäh, Michael F.

311

Investigating the definition of flood maps using a 2D hydraulic routing model forced by a DEM-based fully continuous rainfall-runoff algorithm  

NASA Astrophysics Data System (ADS)

Ongoing efforts of remote sensing technologies to provide more accurate digital elevation models (DEMs) at the global scale are supporting the use of terrain analysis and hydrologic and hydraulic modelling algorithms for flood mapping in ungauged basins. In this work we implement a fully continuous hydrologic-hydraulic model feeded by a rainfall synthetic time series for providing river hydrographs that are routed along the channel using a bidimensional hydraulic model for the detailed physically-based characterization of the inundation process. In this way the whole physical process is represented, from the net rainfall to the flow time series, avoiding any conceptual sub-method (design hyetograph and hydrograph) commonly needed to apply standard flood modelling and mapping procedures. Nevertheless, the floodplain information is no longer deterministic as the result of the evaluation of the impact on the river valley of a single design hydrologic scenario (event-based approach,EBA), but the final result is composed of a combination of data derived by the application of a fully-continuous approach (FCA). Indeed FCA provides a flow depth time series for each single cell of the inundated domain. The final flood map should be, thus, the result of a proper analysis of this dataset in statistical, qualitative and quantitative terms. Otherwise this would lead to an undefined flooding scenario that could be useless for flood risk management and decision making in urban plans.

Nardi, Fernando; Petroselli, Andrea; Grimaldi, Salvatore

2013-04-01

312

Anti-nuclear liberals and the bomb: A comparative history of Kampf dem Atomtod and the Committee for a Sane Nuclear Policy, 1957-1963  

SciTech Connect

The premises of Kampf dem Atomtod (KdA) and Citizens for a Sane Nuclear Policy (SANE) were based on nineteenth century traditions of liberal peace advocacy. Both groups gained substantial public support for their goals to prevent the nuclear armament of the Bundeswehr and to stop nuclear testing. Both organizations won well-educated middle-class and mostly white supporter. The dissertation examines the role of women: whether housewife or doctor, women stressed their special concerns as mothers. Both KdA and SANE had troubled relations with the labor movement. Their leaders hoped to gain government leaders' respect by winning a respectable, non-Communist constituency and claiming their goals were reasonable ones. Government officials attacked KdA and SANE as dupes of Moscow. Many supporters left the organizations because of their strict anti-Communism. Local groups accused their leaders of lacking initative. KdA and SANE's leaders wasted time and energy rehashing issues and postponing decisions. After a period of providing initiatives and ideas local committees disintegrated. Both organizations considered education their paramount goal but their arguments primarily reached the converted, who often preferred more political action. KdA and SANE's leaders instead chose to support respectable projects based on humanitarian ideals. Since these projects offered little in the way of concrete action agendas, supporters defected to more active organizations or slipped into apathy. Neither organization achieved its national goals. Both governments generally denied them access to the policymaking process, ignored them as irrelavant, or attacked them as Communist sympathizers. While SANE and KdA were heard by those concerned by nuclear policy, and while members of SANE's National Board did help muster support for the Partial Test Ban Treaty, both organizations failed to make liberal peace values productive in the nuclear decisionmaking process.

Thiede, B.

1992-01-01

313

Nonlinear Force-Free Magnetic Fields of Active Regions based on automated loop tracing in AIA/SDO images with DEM discrimination of chromospheric and coronal features  

NASA Astrophysics Data System (ADS)

We developed a forward-fitting code that computes a nonlinear force-free magnetic field (NLFFF) solution constrained by line-of-sight magnetograms from HMI/SDO and by coronal loop structures detected in EUV images from AIA/SDO. The 2D coordinates of coronal loop structures are detected with an improved version of the Oriented Coronal CUrved Loop Tracing (OCCULT-2) code, an automated pattern recognition algorithm that has demonstrated a quality and fidelity in loop tracing that matches visual perception. One fundamental limitation in the completeness of detecting coronal loops comes from the background confusion of coronal loop EUV emission with low-temperature (T=10^4-10^6 K) emission from the chromosphere and transition region, as well as T ~ 1.0 MK emission from reticulated ``moss structure'' that stems from the footpoints of hotter (T 2-8 MK) coronal loops. We employ a pixel-wise differential emission measure (DEM) analysis using the 7 coronal AIA filters in order to produce uncontaminated emission measure maps in coronal temperature ranges, which allows an improved performance of automated loop tracing. A nonlinear force-free magnetic field solution is then computed by forward-fitting of an analytical NLFFF solution of twisted coronal field lines to the automatically traced coronal loop coordinates. We demonstrate the performance of this magnetic field modeling for a number of solar active regions observed with SDO. The developed method is able to calculate the most realistic magnetic field models of solar active regions that match all available observable constraints.

Aschwanden, Markus J.; Boerner, P.; AIA/SDO Team

2013-07-01

314

Das Kreuz auf dem Schlachtfeld  

E-print Network

.4.15. [Stamped] 1. Mobl. Landsturm-Inft.-Batl. Heidelberg, 2. Komp. [An] Frä ulein Maria Kolbe, Heidelberg, Kronprinzenstr. 28. Saarburg 11.....4.15. [Stamped] 1st Heidelberg Mobile Home Guard Infantry Battalion, 2nd Company. [To] Ms. Maria Kolbe, Heidelberg, Kronprinzenstr. 28. Saarburg...

Schmidlin, A. [author

2012-03-05

315

Contour to DEM Michael Gousie  

E-print Network

, e.g. area stealing Medial axis Inverse distance weighting. Detect features, interpolate them 3 Nested Squares with Inverse Distance Weighting, and 3 Ways with Delaunay Triangles 7 #12;' & $ Diagonal Slice Interpolating Squares Top to Bottom at Right: Cubic, Inverse Distance, Linear, Nearest, Orig

Franklin, W. Randolph

316

Remote-sensing of Riverine Environments Utilized by Spawning Pallid Sturgeon Using a Suite of Hydroacoustic Tools and High-resolution DEMs  

NASA Astrophysics Data System (ADS)

The pallid sturgeon (Scaphirynchus albus) inhabits sandy-bedded rivers in the Mississippi River basin including the Missouri and Lower Yellowstone Rivers and has experienced decline generally associated with the fragmentation and alteration of these river systems. Knowledge gaps in the life history of the pallid sturgeon include lack of an understanding of conditions needed for successful reproduction and recruitment. We employed hydroacoustic tools to investigate habitats utilized by spawning pallid sturgeon in the Missouri River in Missouri, Kansas, Iowa, and Nebraska, and the Yellowstone River in Montana and North Dakota USA from 2008-2013. Reproductive pallid sturgeon were tracked to suspected spawning locations by field crews using either acoustic or radio telemetry, a custom mobile mapping application, and differential global positioning systems (DGPS). Female pallid sturgeon were recaptured soon after spawning events to validate that eggs had been released. Habitats were mapped at presumed spawning and embryo incubation sites using a multibeam echosounder system (MBES), sidescan sonar, acoustic Doppler current profiler, an acoustic camera and either a real-time kinematic global positioning system (RTK GPS) or DGPS. High-resolution DEM's and velocimetric maps were gridded from at a variety of scales from 0.10 to 5 meters for characterization and visualization at spawning and presumed embryo incubation sites. Pallid sturgeon spawning sites on the Missouri River are deep (6-8 meters) and have high current velocities (>1.5 meters per second). These sites are also characterized by high turbidity and high rates of bedload sediment transport in the form of migrating sand dunes. Spawning on the channelized Lower Missouri River occurs on or adjacent to coarse angular bank revetment or bedrock. Collecting biophysical information in these environmental conditions is challenging, and there is a need to characterize the substrate and substrate condition at a scale relevant to spawning fish and developing embryos (< 1 meter). The Yellowstone River in Montana and North Dakota provides the closest analog to a reference condition for pallid sturgeon spawning habitat with a natural flow regime and relatively natural channel geomorphology. Recent documented suspected spawning on the Yellowstone River occurs in a a sand-bedded reach with patches of gravel deposits, in zones of higher velocity (1.0-1.5 meters per second) compared to the ranges of velocities available in an adjacent reach and over a range of depths (2-5 meters). Results from substrate assessments at pallid sturgeon spawning sites on the Missouri and Yellowstone Rivers may have implications for sediment and flow management as well as provide guidance for potential habitat manipulation in support of the recovery of the pallid sturgeon.

Elliott, C. M.; Jacobson, R. B.; DeLonay, A. J.; Braaten, P. J.

2013-12-01

317

Bewegungstherapie zwischen 1900 und 2000 – Momentaufnahmen einer Entwicklung  

Microsoft Academic Search

\\u000a Bewegung wurde als „Heilmittel“ im 19. Jhd. wiederentdeckt. Die „schwedische Heilgymnastik” eroberte auch Deutschland, wo\\u000a 1900 die erste Lehranstalt für Heilgymnastik in Kiel gegründet wurde. Gekennzeichnet war diese Heilgymnastik durch schablonenhaft\\u000a vorgegebene Bewegungsformen, meist mit apparativer Unterstützung (ZANDER-Apparate). Dauerdehnungen mit Zügen und Gewichten\\u000a (Redression) und das Üben einzelner Gelenke und Muskeln standen im Vordergrund. Daran änderte sich bis in die

A. Hüter-Becker

318

Analyse und Simulation elektrischer Wechselwirkungen zwischen Implantaten und Biosystemen  

E-print Network

.-Phys. Andreas Körtge AG Beck, Gerätesysteme & Schaltungstechnik Dipl.-Math. Harald Birkholz AG Engel, Mathematik Dipl.-Ing. Annekathrin Grünbaum AG Pau, HNO Dipl.-Inf. Ralf Warmuth AG Salomon, Techn. System

Rostock, Universität

319

Analyse arztstrafrechtlicher Ermittlungsverfahren der Staatsanwaltschaft Aachen zwischen 1978 und 1981  

Microsoft Academic Search

Altogether, 318 preliminary proceedings were initiated against physicians, compared to 2 against nonmedical practitioners. The majority i.e., 192 proceedings, dealt with charges of torture and deprivation of freedom committed against patients under psychiatric treatment. Ninety-nine proceedings were based on negligent bodily injury and negligent homicide and 15 on failure to give medical assistance. Other reasons were given in isolated cases

H. Althoff; Th. Solbach

1984-01-01

320

Zum Briefwechsel zwischen Gottfried Kirch und Gottfried Wilhelm von Leibniz  

Microsoft Academic Search

\\u000a Summary  Between June 1702 and December 1708 the astronomer, Kirch in Berlin and the philosopher, Leibniz in Hannover exchanged eleven\\u000a letters. The letters from Leibniz to Kirch were published in 1900. The author will prove in this article, that the letters,\\u000a which are kept in the Leibniz-Archives in Hannover, are Kirch's original answers to Leibniz. For first time, these letters\\u000a will

Klaus-Dieter Herbst

1994-01-01

321

Black Hawk Down: Film Zwischen Reflektion und Konstruktion Gesellschaftlicher Wirklichkeit  

NASA Astrophysics Data System (ADS)

BLACK HAWK DOWN: FILM BETWEEN THE REFLECTION AND CONSTRUCTION OF SOCIAL REALITY - In this article, Ridley Scott's film Black Hawk Down (USA 2001) is read in the context of contemporary theories concerning cultural memory (Jan and Aleida Assmann) and media culture (Douglas Kellner). It is argued that film (and representation in general) does not merely reflect a preceding reality; it also actively serves to construct it. It is shown how Scott's film privileges one particular perspective on an actual event and how this point of view is objectified and installed in the memory of Western media culture. What potential implications does an increased blurring of fact and fiction in the representation of war have? What are the consequences for political and pedagogical practice? What role can cultural studies play in these processes?

Pötzsch, Holger

2009-05-01

322

Politische Strategien der MILF zwischen Djihadismus und Verhandlungstisch  

Microsoft Academic Search

Nach Jahrzehnten sozialer und politischer Repression erwachte im Jahr 1968 das politische Bewusstsein der muslimischen Bevölkerung Mindanaos. Im Jahr 1969 gründete der säkulare Moslem Nurullaji Misuari die Moro National Liberation Front (MNLF), die bald die Führung im Widerstand gegen die philippinische Zentralregierung übernahm. Ideologische Spannungen innerhalb der MNLF führten seit 1976 zum Ende ihrer organisatorischen Einheit: Eine Fraktion hatte sich

Nicole Klitzsch

2006-01-01

323

Estimation of daily average net radiation from MODIS data and DEM over the Baiyangdian watershed in North China for clear sky days  

NASA Astrophysics Data System (ADS)

SummaryDaily average net radiation (DANR) is a critical variable for estimation of daily evapotranspiration (ET) from remote sensing techniques at watershed or regional scales, and in turn for hydrological modeling and water resources management. This study attempts to comprehensively analyze physical mechanisms governing the variation of each component of DANR during a day, with the objective to improve parameterization schemes for daily average net shortwave radiation (DANSR) and daily average net longwave radiation (DANLR) using MODIS (MODerate Resolution Imaging Spectroradiometer) data products, DEM, and minimum meteorological data in order to map spatially consistent and reasonably distributed DANR at watershed scales for clear sky days. First, a geometric model for simulating daily average direct solar radiation by accounting for the effects of terrain factors (slope, azimuth and elevation) on the availability of direct solar radiation for sloping land surfaces is adopted. Specifically, the magnitudes of sunrise and sunset angles, the frequencies of a sloping surface being illuminated as well as the potential sunshine duration for a given sloping surface are computed on a daily basis. The geometric model is applied to the Baiyangdian watershed in North China, with showing the capability to distinctly characterize the spatial pattern of daily average direct solar radiation for sloping land surfaces. DANSR can then be successfully derived from simulated daily average direct solar radiation by means of the geometric model and the characteristics of nearly invariant diffuse solar radiation during daytime in conjunction with MCD43A1 albedo products. Second, four observations of Terra-MODIS and Aqua-MODIS land surface temperature (LST) and surface emissivities in band 31 and band 32 from MOD11A1, MYD11A1 and MOD11_L2 data products for six clear sky days from April to September in the year 2007, are utilized to simulate daily average LST to improve the accuracy of estimates of DANLR. Comparisons of the DANLR estimates from the proposed four observation-based method and that from an existing one observation-based method, against that from the Penmen equation solely using routine meteorological data indicates that the proposed method is capable of more accurately simulating DANLR than is the one observation-based method. Using the Penman equation as a reference, results show that overall the proposed method has a bias of 2.7 W m -2 and a root mean square error (RMSE) of 12.8 W m -2, whereas the one observation-based method has a bias of -33.3 W m -2 and a RMSE of 39.6 W m -2 across 18 weather stations for six tested days. In general, simulated DANR is shown to be reasonable over the entire study watershed for the six clear sky days as a result of the improvement in the parameterization schemes of DANSR and DANLR. The resulting DANR would serve well as a critical variable linking instantaneous evaporative fraction to the estimates of daily ET primarily from remotely sensed data.

Long, Di; Gao, Yanchun; Singh, Vijay P.

2010-07-01

324

Die Amtliche Sammlung von Untersuchungsverfahren nach § 64 LFGB, § 35 Vorläufiges Tabakgesetz und § 28b Gentechnikgesetz - ein Instrument der amtlichen Lebensmittelüberwachung  

NASA Astrophysics Data System (ADS)

Immer wieder werden Skandale in Zusammenhang mit Lebensmitteln bekannt. Schlagworte wie BSE, Gammelfleisch, Acrylamid, Cumarin oder auch Melamin, Dioxin sind den Verbrauchern geläufig und erschüttern das Vertrauen in ein gesundes und ernährungsphysiologisch wertvolles Lebensmittel. Das Bewusstsein des Verbrauchers hinsichtlich der Ernährung und der Auswahl beim Kauf der Lebensmittel hat sich in den vergangenen Jahren deutlich verändert. Bei der Auswahl seiner Lebensmittel liegt sein Augenmerk verstärkt auf gesunden, qualitativ hochwertigen und vor allem sicheren Lebensmitteln. Dies wurde insbesondere bei dem verhaltenen Kauf von Fleisch und Fleischerzeugnissen während der BSE-Krise oder auch dem kürzlich aufgetretenen Gammelfleischskandal deutlich.

Renger, Silke; Stachel, Carolin

325

Anschauliche Herleitung und Beweis des Baranow-Schaefer-Verfahrens zum Ermitteln der Eigenschwingungszahlen und der Eigenschwingungsformen von Schwingerketten  

Microsoft Academic Search

Zusammenfassung  Nach dem Verfahren von G. Baranow und seiner Erweiterung durch H. Schaefer kann man die Frequenz und die Schwingungsform der\\u000a Eigenschwingungen von Schwingerketten sehr einfach auf graphischem Wege durch Reduktion erhalten. Auf Grund einer anschaulichen\\u000a Herleitung geland es, die dynamischen und kinematischen Beziehungen zwischen einer gegebenen Schwingerkette und den nach dem\\u000a Baranow-Schaefer-Verfahren aus ihr erhaltenen Schwingungssystemen aufzustellen und den Beweis

E. Pestel

1955-01-01

326

Lufthansa: Mit Employer Branding die Richtigen finden  

Microsoft Academic Search

\\u000a Die Gewinnung und Auswahl der richtigen Mitarbeiter ist ein entscheidender Wettbewerbsvorteil für jedes Unternehmen – auch\\u000a für Lufthansa. Relevante Erfolgsfaktoren sind die Pflege oder die Stärkung der Arbeitgebermarke, Wirtschaftlichkeit, entsprechendes\\u000a Kostenmanagement und die nachhaltige Etablierung von Standardprozessen. Personalmarketer stehen dabei in einem Spannungsfeld\\u000a zwischen dem Qualitätsanspruch der personalsuchenden Fachbereiche („more specific“ und „best available“), dem viel zitierten\\u000a „(New) War for

Doris Krüger

327

Vergleichende Untersuchungen über das Spannen von Kreissägeblättern mit Maschinen und mit Richthämmern  

Microsoft Academic Search

Zusammenfassung  Bei dem bisher gebruchlichen Spannen von Kreissgeblttern mit Richthmmern von Hand ist es nicht mglich, die Schlge in\\u000a ihrer Gre und Lage genau festzulegen. Dadurch entstehen unvermeidlich unterschiedliche Materialverdichtungen bzw. rtliche\\u000a berbean-spruchungen. Es wurden daher maschinelle Verfahren zur Erzielung einer gleichmigen Spannung untersucht. Frhere\\u000a Arbeiten des Instituts fr Werkzeugforschung Remscheid zeigten, da zwischen dem Arbeitsverhalten von Kreissgeblttern enerseits\\u000a und den

Eginhard Barz

1963-01-01

328

New insights into palaeoglaciological processes in northeastern Germany by analysis of a LiDAR DEM: using high-resolution elevation data to reassess the geomorphology of the Barnim till plain  

NASA Astrophysics Data System (ADS)

We used airborne LiDAR DEM data to reassess the current state of research of an intensively studied "classical" glacial landscape, the Barnim till plain northeast of Berlin. To gain new insights into palaeoglaciological dynamics, we examined a high-resolution DEM for geomorphic features that either prove or negate previous research. The study area was last glaciated in the Weichselian, and its landforms are associated with the W1B- (Brandenburg phase) and W1F-advances (Frankfurt phase), except for the eastern Barnim where a push moraine complex was compressed during the Saalian. The course and the timing of the W1F ice marginal position, which is assigned to the Barnim area, are contradictorily discussed in literature. Hence, landscape analysis with a high resolution DEM appears to be a promising tool. The LiDAR data used here has a ground resolution of 1 m and a height accuracy of 30 - 50 cm. In an ArcGIS 10 environment a database was created that contains spatial information about the study area collected from different sources. These include digitized geological and geomorphological maps as well as geochronological data from different authors. Owing to the size of the Barnim (~1900 km²), three subsets with a size of 10 x 15 km were selected for advanced analysis (western, middle and eastern Barnim). Each subset represents one of the most characteristic landscapes of the study area. For each subset we performed a qualitative analysis of landscape features. The results were compared with each other and connected to the whole Barnim area as well as the current state of research. The most remarkable discovery was made in the middle Barnim. Here we identified a set of consecutive arcuate ridges. Their widths (NE-SW) are around 1000 - 1500 m, and their lengths are around 10 - 15 km; they rise some 10 m above their surroundings. According to geological maps and our own fieldwork, they are covered by till. A sandy or peaty substrate lies between the ridges. The inner sides of the ridges are northeast-oriented and rather steep, and the outer sides face southwest with a dip at a flatter angle. The ridges are incised radially. Their lobe-like form and the distribution of the substrates suggest a glacial origin. We propose a genetic model of recessional moraines that were deposited in front of an oscillating glacier lobe; however, other possibilities are also discussed. Similar forms were recently found around the ice margin of piedmont glaciers, e.g. the Malaspina glacier in southwest Alaska. The timing of their formation still has to be investigated. Fine gravel analyses from other studies imply that they consist of a till that can probably be associated with a Weichselian ice advance. Understanding the genesis of the newly described ridges may be a key to solve the contradictory "Frankfurt phase problem" in terms of glaciodynamics and stratigraphy Our study shows that even in intensively researched areas high-resolution DEM data can reveal landscape features that shed a new light on landscape genesis. Nevertheless, further fieldwork and geochronological data are necessary to obtain a complete picture of palaeoglaciological processes in the northeastern German lowland.

Hardt, Jacob; Böse, Margot; Hebenstreit, Robert; Lüthgens, Christopher

2014-05-01

329

The use of DEM analysis for structural characterization of landslide-prone areas in crystalline rock slopes using GIS-based techniques. The case of the Matter Valley, Switzerland  

NASA Astrophysics Data System (ADS)

Mountainous regions influenced by glacial processes are often prone to slope instabilities. One reason for this relationship is their characteristic morphology (high relief and steep slopes) and the surface processes associated with glacial advance and retreat. In the Matter Valley, Switzerland these factors interact with brittle-ductile faults and joint sets and induce rock slope failures at multiple scales, including the 3x107 m3 Randa and the 1x105 m3 Medji events. The general lithological and tectonic disposition in the study area is quite homogeneous, while the local fracture systems and their characteristics vary spatially. These features provide the opportunity to evaluate potential relationships between the local fracture systems and the potential failure modes they develop with the observed slope morphology and its state of stability. In order to investigate this hypothesis the fracture pattern of the area was analyzed using a new combination of data collected from the field and data extracted from an aerial-based LIDAR high resolution DEM (SWISSTOPO, 2m pixel resolution). This is possible for the area because the fracture pattern has been observed to have a strong influence in the morphology of the slopes. To identify slope faces controlled by structures a 3D shaded relief map of the area was produced. A 3D shaded relief map is a color-coded image based on HSV color composition showing changes in color according with the changes on slope orientation (dip and dip direction). A careful selection of the planes used for the analysis was carried out taking in consideration that not all values in the 3D shaded relief image represent fracture orientations; this is due to multiple factors such as cell size of the DEM, presence of land cover (soil), and presence of overhanging blocks. Selection of cells was done using 3D visualizations (an orthophoto mosaic created with aerial photographs acquired in 2005 was used as the top-most layer) and photographs of the slopes taken from different angles during the field data collection campaigns. The orientation values extracted from the DEM analysis needed an areal value correction. This correction is based on the fact that steep slopes are represented for a fewer number of cells than gentle slopes. A total of more than 120000 fracture orientations were obtained from this analysis and displayed in a total of 45 stereoplots. Field data and DEM derived data were compared each other and with data of previous works in order to assess the reliability of the method. As a product of the analysis the area was divided in two main structural domains based on the spatial distribution of the fracture patterns. These domains have shown a clear connection with the frequency of instabilities and therefore with the differences in morphology of the slopes.

Yugsi Molina, F. X.; Loew, S.; Button, E.

2009-04-01

330

Zielorientierung und Bezugsnormorientierung: Zum Zusammenhang zweier Konzepte Goal Orientation and Reference-Norm Orientation: Two Related Constructs?  

Microsoft Academic Search

Zusammenfassung: Zielorientierungen und Bezugsnormorientierungen sind zwei innerhalb der Pädagogi- schen Psychologie ausgesprochen fruchtbare Konstrukte, die sich sowohl aufgrund ihrer Entstehung als auch ihrer konkreten Inhalte deutlich unterscheiden. Dennoch werden beide Konstrukte argumentativ häu- fig miteinander in Beziehung gebracht, ohne dass bis heute eine empirische Überprüfung dieser Beziehung erfolgte. In der vorliegenden Untersuchung überprüfen wir die Annahme, dass Personen solche Bezugsnor-

Bern Huber; Claudia Schöne; Oliver Dickhäuser

331

Modellbasierter Modultest technischer  

E-print Network

zwischen dem Lehrstuhl von Prof. Dr. Peter Liggesmeyer und der Siemens AG, München, Abteilung Corporate Technology (CT PP 2). An erster Stelle möchte ich Prof. Dr. Peter Liggesmeyer für die Möglichkeit zur Wegbegleiterin und meine wichtigste Ratgeberin war. Mein Dank gilt an dieser Stelle auch Jens Scheffermann und

Weske, Mathias

332

Een opwekking om voort the gaan met het kruisen van individuen tot verschillende linneonten van get geslacht Verbascum behoorend  

Microsoft Academic Search

Résumé Aus der Litteratur wird gezeigt, dassDarwin einen Bastard vanVerbascum thapsus x lychnitis gehabt hat, welche mit dem Pollen beider Eltern einige wenige Samen gab und dassMendel einen Bastard zwischenVerbascum phoeniceum undV. blattaria gehabt hat, welche bei Selbstbefruchtung über 100 gut ausgebildete Samen producirte. Über die Nachkommen dieser Samen wird leider nicht berichtet.

J. P. Lotsy

1920-01-01

333

Entwicklung und Aufbau einer Population der Silbermöwe, Larus argentatus argentatus  

Microsoft Academic Search

X. Zusammenfassung Die neben dem Institutsgebäude der Vogelwarte Helgoland in Wilhelmshaven gelegene Silbermöwenpopulation nahm ihren Anfang mit 2 Paaren im Jahre 1948, wuchs bis 1955 auf 51, 1956 auf über 100 Paare an und schwankte 1957–1959 zwischen 127 und 139 Paaren. 1960 waren es mindestens 150 Paare.

R. Drost; E. Focke; G. Freytag

1961-01-01

334

Institut f ur Informatik SS 2002 der Universit at M unchen  

E-print Network

Problem der Berechnung k urzester Wege von einem Startknoten mittels des #12;-Produktes von Matrizen und Vek- toren ausdr uckt, und dass das Auswerten dieses Produktes dem Algorithmus von Bellman Minimaldistanz zwischen allen Paaren von Knoten so, dass sie eine Matrix #5; = #25;(i; j) #1; ausgeben. Diese

Abel, Andreas

335

Contentious food politics: sozialer Protest, Märkte und Zivilgesellschaft (18. - 20. Jahrhundert)  

Microsoft Academic Search

Subsistenzproteste (food riots, Lebensmittelunruhen) sind eine historisch wie aktuell ubiquitäre Variante sozialen Konflikts. Sie sind Bestandteil einer weithin noch ungeschriebenen Sozial- und Mentalitätengeschichte von Märkten. Hier in einem weitergefaßten Sinn als contentious food politics thematisiert, werden darunter strittige Aushandlungsprozesse zwischen verschiedenen Gesellschaftsgruppen, sowohl unmittelbar gegeneinander wie auch mit dem Staat, um Zugang bzw. Verfügung über lebenswichtige Grundnahrungsmittel verstanden. Letzthin umschreibt

Manfred Gailus

2004-01-01

336

HEIDELBERGER VORTRGE ZUR KULTURTHEORIE  

E-print Network

-WALLBRECHT (HEIDELBERG) Hörsaal 14 der Neuen Universität Mittwoch, 23. Oktober 2013, 19 Uhr s.t. JOHANN WOLFGANG VON GOETHE: WEST-ÖSTLICHER DIVAN EIN LIEBESGESPRÄCH ZWISCHEN HATEM UND SULEIKA MIT KLAVIERSTÜCKEN VON CLAUDE VON DR. TAREK TAWFIK (KAIRO) GESPRÄCH MIT DEM REFERENTEN UND DR. GABRIELE BERRER

Heermann, Dieter W.

337

Verkndungsblatt 16|2008 Ausgabedatum 28.10.2008  

E-print Network

VG Dienstvereinbarung nach § 78 des Niedersächsischen Personalvertretungsgesetzes zwischen der Gottfried Wilhelm Leibniz Universität Hannover und dem Personalrat der Gottfried Wilhelm Leibniz Universität Hannover zum Einsatz der.uni-hannover.de/de/universitaet/veroeffentlichungen/verkuendungsblaetter/ #12;Verkündungsblatt der Gottfried Wilhelm Leibniz Universität Hannover vom 28.10.2008 16/2008 Die

Vollmer, Heribert

338

kM C d KidMensaCard Kids kostenloses Essen in der Mensa fr Kinder von Studierenden  

E-print Network

kM C d KidMensaCard Kids kostenloses Essen in der Mensa für Kinder von Studierenden Über 150 immer einfach. Ab jetzt gibt es die MensaCard Kids für Kinder zwischen 0 und 10 Jahren! Wir danken dem Studentenwerk Hannover für die Unterstützung.g Wie funktioniert die MensaCard Kids? · gültig für Studierende mit

Manstein, Dietmar J.

339

On the nature of scientific laws and theories  

Microsoft Academic Search

Zusammenfassung Ist der Unterschied zwischen wissenschaftlichen Gesetzen und Theorien ein qualitativer oder lediglich von quantitativer Art? Der Autor versucht zu zeigen, daß Gesetze und Theorien fundamental verschieden sind und daß die Kenntnis ihrer verschiedenen Natur notwendig für ein richtiges Wissenschaftsverständnis ist. Aus seiner Sicht sind Theorien geistigeKonstruktionen mit dem Ziel,kausale Erklärungen von empirischen Gesetzen zu geben, während diese Gesetze auf

Craig Dilworth

1989-01-01

340

Dual site of action of phenoxybenzamine in the cat's spleen: Blockade of ?-adrenergic receptors and inhibition of re-uptake of neurally released norepinephrine  

Microsoft Academic Search

Zusammenfassung An der isoliert durchströmten Milz der Katze wird durch Phenoxybenzamin die bei elektrischer Reizung der Milznerven im venösen Ausfluss erscheinende Noradrenalinmenge vermehrt. Es besteht keine zeitliche und quantitative Korrelation zwischen dieser Noradrenalinvermehrung und dem Ausmass der adrenergen Blockierung. Phenoxybenzamin scheint die Vermehrung des Noradrenalins im venösen Ausfluss durch eine Blockierung der Wiederaufnahme in die Speicher und nicht durch die

H. Thoenen; A. Hürlimann; W. Haefely

1964-01-01

341

Shape-selected nanocrystals for in situ spectro-electrochemistry studies on structurally well defined surfaces under controlled electrolyte transport: A combined in situ ATR-FTIR/online DEMS investigation of CO electrooxidation on Pt  

PubMed Central

Summary The suitability and potential of shape selected nanocrystals for in situ spectro-electrochemical and in particular spectro-electrocatalytic studies on structurally well defined electrodes under enforced and controlled electrolyte mass transport will be demonstrated, using Pt nanocrystals prepared by colloidal synthesis procedures and a flow cell set-up allowing simultaneous measurements of the Faradaic current, FTIR spectroscopy of adsorbed reaction intermediates and side products in an attenuated total reflection configuration (ATR-FTIRS) and differential electrochemical mass spectrometry (DEMS) measurements of volatile reaction products. Batches of shape-selected Pt nanocrystals with different shapes and hence different surface structures were prepared and structurally characterized by transmission electron microscopy (TEM) and electrochemical methods. The potential for in situ spectro-electrocatalytic studies is illustrated for COad oxidation on Pt nanocrystal surfaces, where we could separate contributions from two processes occurring simultaneously, oxidative COad removal and re-adsorption of (bi)sulfate anions, and reveal a distinct structure sensitivity in these processes and also in the structural implications of (bi)sulfate re-adsorption on the CO adlayer. PMID:24991511

Jusys, Zenonas; Behm, R Jürgen

2014-01-01

342

Dynamic observations of the 8 January 2010 pyroclastic flow from the Soufriere Hills Volcano, Montserrat ascertained by high-definition and FLIR video analysis, as well as geometric analysis of the DEM  

NASA Astrophysics Data System (ADS)

On January 8th 2010, Soufriere Hills Volcano (Montserrat) experienced a collapse of the northwestern part of its andesitic lava dome. The ensuing explosive event lead to a 8.3 km high eruption column and generated a pyroclastic density current (PDC) that propagated down the northern flank of the volcano, moving down the Belham valley. This PDC was recorded from the Montserrat Volcano Observatory using both normal High- Definition and Forward Looking Infrared (FLIR) video cameras. The flow front velocity profile, plus the vertical motion of discrete buoyant thermals ascending above the PDC, were measured by combining the video data with a deposit map and a high spatial-resolution DEM. A theoretical treatment was then applied to extract key parameters that describe the buoyant motion of thermals ascending above the current (including density, particle mass volume fraction, and temperature). Interaction of the PDC with topographic features corresponded to important changes in the dynamics of the PDC as well as the ascent of the buoyant ash-clouds These interactions included an increase of the ascent rate of buoyant thermals when the PDC encountered topographic barriers, and deceleration of the flow front velocity due of high degrees of valley sinuosity. Additionally, a major change in flow dynamics was visible in our data 2 - 3 km from the dome. To investigate this further, channel slope, sinuosity, and cross-sectional area were measured from high-resolution DEMs using GIS software; and were compared to geometric parameters of the mapped ash-cloud surge deposits. The data illustrate three surge generation regimes: a proximal area of rapid lateral expansion; a medial deflation zone; and a steadier distal surge 'fringe'. These surge regimes relate directly the dramatic change in buoyant thermal flow dynamics observed 2-3 km from the dome and are also correlated with velocity and inversely correlated with valley cross-sectional area. Several possible origins can be proposed to explain this change, including changes in internal factors (i.e. degree of fluidization, sedimentation rate, and ash generation from block fragmentation) and/or external factors (influence of topographic barriers, changes in slope, sinuosity, valley-holding capacity). Complementary laboratory and dynamical observation would better constrain variations in the dynamics. Areas of topography-induced increases in velocity and inter-granular collisions are interpreted to result in more pervasive fluidization and thus enhanced surge generation. Distally, surge deposits appear as fringes with decaying extents, indicative of more passive expansion and decreasing velocity. The results indicate that surge mobility and detachment are a complex product of flow mass flux and topography and that future efforts to model dense-dilute coupled flows will need to account for and integrate several mechanisms acting on different parts of the flow.

Molle, A.; Ogburn, S. E.; Calder, E. S.; Roche, O.; Harris, A. J.

2012-12-01

343

Verteilte Dienstnutzung mit dem neuen Personalausweis  

Microsoft Academic Search

Authentication using user name and password bears various\\u000d\\u000arisks such as eavesdropping by malware. Authentication mechanisms based on\\u000d\\u000asmart cards avoid such attacks by requiring possession of the card, but are\\u000d\\u000aoften not applicable due to missing card readers. The direct connection\\u000d\\u000abetween reader and user system allows for attacks e.g. when typing in the PIN\\u000d\\u000avia the user system.

M. Horsch; J. Braun; A. Wiesmaier; J. Schaaf; C. Baumller

2012-01-01

344

Unter dem Titel Markov Processes linking  

E-print Network

¨ur Physik Fakult¨at f¨ur Mathematik und Naturwissenschaften Carl von Ossietzky Universit¨at Oldenburg Dipl of fluctuation theorems to thermodynamic systems are dependent on a reliable statistics of rare events. To access the statistics of rare events, an asymptotic method is developed. The first order asymptotics is derived

Peinke, Joachim

345

Diesel Exhaust in Miners Study (DEMS)  

Cancer.gov

In March 2012, the National Cancer Institute (NCI) and the National Institute for Occupational Safety and Health (NIOSH) completed a retrospective cohort mortality and nested case-control study of 12,315 workers at eight non-metal mining facilities to investigate risk of lung cancer in relation to quantitative measures of historical exposure to diesel exhaust, after taking into account smoking and other lung cancer risk factors

346

DEM simulation of growth normal fault slip  

NASA Astrophysics Data System (ADS)

Slip of the fault can cause deformation of shallower soil layers and lead to the destruction of infrastructures. Shanchiao fault on the west side of the Taipei basin is categorized. The activities of Shanchiao fault will cause the quaternary sediments underneath the Taipei basin to become deformed. This will cause damage to structures, traffic construction, and utility lines within the area. It is determined from data of geological drilling and dating, Shanchiao fault has growth fault. In experiment, a sand box model was built with non-cohesive sand soil to simulate the existence of growth fault in Shanchiao Fault and forecast the effect on scope of shear band development and ground differential deformation. The results of the experiment showed that when a normal fault containing growth fault, at the offset of base rock the shear band will develop upward along with the weak side of shear band of the original topped soil layer, and this shear band will develop to surface much faster than that of single top layer. The offset ratio (basement slip / lower top soil thickness) required is only about 1/3 of that of single cover soil layer. In this research, it is tried to conduct numerical simulation of sand box experiment with a Discrete Element Method program, PFC2D, to simulate the upper covering sand layer shear band development pace and scope of normal growth fault slip. Results of simulation indicated, it is very close to the outcome of sand box experiment. It can be extended to application in water pipeline project design around fault zone in the future. Keywords: Taipei Basin, Shanchiao fault, growth fault, PFC2D

Chu, Sheng-Shin; Lin, Ming-Lang; Nien, Wie-Tung; Chan, Pei-Chen

2014-05-01

347

Dem Bones Forensic Resurrection of a Skeleton  

NSDL National Science Digital Library

In this case study, a forensic anthropologist must determine the age and sex as well as look for signs of trauma to a skeleton found in a shallow grave in a state park. Students simulate the actual procedures used in a forensics lab and learn to identify bones, landmarks, and anatomical features associated with sex, age, height, and pathology. The case was developed for use in a freshman-level human anatomy and physiology course. It could also be used in biology, anatomy, and anthropology courses.

Alease S. Bruce

2001-01-01

348

Dem Bones: Forensic Resurrection of a Skeleton.  

ERIC Educational Resources Information Center

Presents an activity for students to determine the sex and age of an individual from a collection of bones. Simulates some of the actual procedures conducted in a forensic anthropologist's lab, examining and identifying bones through a series of lab activities. (Author/ASK)

Bruce, Alease

2001-01-01

349

Aus dem Inhalt ,,Willkommen zur besten Weihnachts-  

E-print Network

.387 Die fundamentale Welt der Physik in der Weihnachtsvorlesung 2007 Von Rollerblades und Tornados Mit-Experiment veranschaulicht. Welche Kräfte wirken bei der Entste- hung eines Tornados? In einer durch- sichtigen

Vollmer, Heribert

350

WESTLICHE INTERVENTIONSPOLITIK SEIT DEM KALTEN KRIEG Expertenkonferenz  

E-print Network

Scholar bei Carnegie Europe/Brüssel Moderation: Prof. Dr. Stephan Bierling Universität Regensburg #12: Bei Fragen zu Programm und Organisation, wenden Sie sich bitte an Christine Hegenbart (Tel. +49(0)89-1258-297) oder Irene Krampfl (Tel. +49(0)89-1258-241). Tagungsort: Universität Regensburg | H24 (Vielberth

Schubart, Christoph

351

Studien in dem Romanstil Otto Ludwigs  

E-print Network

gewaltsamen Emporraffan." S. 44. —- "Die Morgenschmieden erhobjöljGh. Wie sie daher karn^ glick sie einer rückwärts wandelnden Schwarzwälder Uhr, arider das Haubenfleckchen das Zifferblatt — — . " S. 4^. — "Das erste Wort jedes Absatzes stellte einen...

Trovillo, Bessie

1910-01-01

352

Weichteile von Fossilien aus dem Erdaltertum  

NASA Astrophysics Data System (ADS)

Phosphatisation of small, soft-bodied fossils in the Upper Cambrian of Sweden yielded rich faunal assemblages, mainly of arthropods, which have been isolated from the rock by etching techniques. The highly diverse fossils are uncompressed and constitute the best preserved material known from the Paleozoic era, exposing minute details such as fine bristles, pores of glands, and eyes. Agnostus clearly has biramous appendages and therefore, cannot be regarded as trilobite anymore. The Crustacea are the most widespread components of the phosphatised fauna. The representatives of a separate order of Ostracoda already have been studied in some detail. Other primordial crustaceans include nauplius stages and show a surprising diversity in specialisation. A similar occurrence in Upper Devonian from the Carnic Alps demonstrates that this mode of preservation is not restricted to a single environment, but also can be expected elsewhere.

Müller, Klaus J.

1982-06-01

353

Future earthquake source faults on deep sea-floor around the Boso triple plate junction revealed by tectonic geomorphology using 3D images produced from 150 meter grid DEM  

NASA Astrophysics Data System (ADS)

Boso triple junction, which is the only example of a triple trench junction on earth, is located off the southeast of Boso peninsula, where the Izu-Bonin trench meets with the Japan trench and the Sagami trench. Boso submarine canyon, which is extended to Katsuuma basin about 7000m deep, forms an incised meander along the north side of Sagami trough. Taito spur separate Katsuuma basin from Bando abyssal basin about 9000m deep, where Japan trench meet with Isu-Bonin trench. In this paper, we present detailed stereo-paired topographic images produced from 0.002 degree (about 150m) DBEM (Digital Bathymetry Model), which processed from the depth sounding data obtained by Japan Coast Guard and JAMSTEC around Boso triple junction. It enables us to observe submarine geomorphology easily and precisely. We identified submarine active faults and other tectonic features related to subduction by using the similar standard for air-photo interpretation of inland active faults. We made more precise submarine active tectonic geomorphological map around Boso triple junction than that by previous workers. Numerous distinct faults on the so-called outer rise associated with subduction of Pacific plate are regarded as normal faulting as widely accepted. While the normal faults on the outer rise are parallel to the trench in the southern part of the Japan trench and the northern part of the Izu-Bonin trench, these normal faults around the east of the triple junction with NNW-SSE extend slightly oblique to the trench. The western margin of Bando abyssal basin is bounded by the thrust faults, which form east-facing 200-500m-high convex scarps associated with raised basin floor to the west of the scarp. These faults also deform Mogi submarine fan surface and uplift to the west along the extension of the scarp. The antecedent valley is extended for about 10km across Taito spur that is an active anticlinal ridge about 1000m high. Katsuura basin is surrounded by terraced former basin floor that is tilted to the west, indicating up-growing of Taito spur. Northeastern part of Izu bar on Philippine Sea plate is characterized by rather smooth extensive convex slope between 1500m-7500m for over 200km long along the trench. On the lower part of the slope below 6000m, several gullies such as Mikura canyon and Kita-Hachijo canyon dissecting the slope forms rapids, probably due to continuous up-warping by subsurface thrusting dipping to the west under the slope. It is noteworthy that we can identify prominent active tectonic features on even very deep sea-floor along the plate boundaries, by using 3D images produced from 150 meter grid DEM.

Goto, H.; Nakata, T.; Watanabe, M.; Suzuki, Y.; Izumi, N.; Nishizawa, A.; Horiuchi, D.; Kido, Y. N.

2013-12-01

354

Untersuchungen über die Nitratreduktion der Grünalge Ankistrodesmus braunii in vivo und in vitro  

Microsoft Academic Search

Zusammenfassung 1.Phasen maximalen Wachstums und optimaler Aktivität der Nitrat und Nitrit reduzierenden Systeme vonAnkistrodesmus braunii liegen zwischen dem 10. und 14. Tag nach Beginn der Kultur.2.Nitrat- und Nitritreduktion unterliegen einer jahreszeitlichen Rhythmik (Maximum im Juli, Minimum im Oktober).3.Neben spezifischen Enzymen sind an der Gesamtnitrat- und Gesamtnitritreduktion intakter Zellen nichtenzymatisch reduzierende Systeme (unter anderem Ascorbinsäure?) beteiligt, deren Aktivität im sauren ph-Bereich

Franz-Christian Czygan

1963-01-01

355

Zur Morphologie des Gynözeums von Berberis  

Microsoft Academic Search

Zusammenfassung An Hand abnorm dimerer Gynözeen vonBerberis vulgaris wird die Frage nach einer möglichen Pseudomonomerie desBerberis-Pistills neuerlich aufgeworfen. Der hier mögliche Vergleich zwischen sicheren Einzelkarpellen mit dem normalen Pistill ergibt aber einwandfrei, daß in beiden Organen die Bündel einander vollkommen entsprechen, daß also im normalen Gynözeum keine Restbündel eventuell eingeschmolzener Karpelle vorhanden sind und daß dieses Gynözeum somit echt monomer

Walter Leinfellner

1957-01-01

356

„Überholen ohne einzuholen“ Die Entwicklung von Technologien für übermorgen in Kernenergie und Mikroelektronik der DDR  

NASA Astrophysics Data System (ADS)

Dem nuklearen Patt zwischen Ostblock und westlichem Staatenbündnis ist es nach weitgehend übereinstimmender Auffassung von Politik und Wissenschaft zu danken, dass der "Kalte Krieg" in der zweiten Hälfte des 20. Jahrhunderts nicht zum weltumfassenden Flächenbrand eskalierte. An der raschen Herstellung dieses Patts waren zwei Dresdner Physiker maßgeblich beteiligt, deren einer im Manhattan-Projekt in den USA gearbeitet hatte und später in England der Spionage für die Sowjetunion und des Verrats des Know-how der Atombombe überführt wurde.

Barkleit, Gerhard

357

Unfälle mit motorisierten Zweirädern  

NASA Astrophysics Data System (ADS)

Der Fahrer eines Pkw Opel Astra überquerte mit seinem Pkw von einer untergeordneten Einmündung kommend eine außerörtliche Bundesstraße in gerade Richtung. Dabei kam es zur Kollision mit einem sich von rechts vorfahrtsberechtigt annähernden Krad Suzuki RGV250. Der Anprall des Krades erfolgte mit dem Heck an die rechte Pkw-Flanke zwischen vorderem Radausschnitt und Fahrzeugecke. Der Krad-Fahrer, welcher sofort tot war und das Zweirad verklemmten sich am Pkw und verblieben relativ zu selbigem annähernd in Kollisionsstellung.

Tschirschwitz, Christian

358

Web 3.0  

Microsoft Academic Search

\\u000a Am 5. Juni 2008 defi nierte der Leiter des Deutschen Forschungszentrums für Künstliche Intelligenz (DFKI) Professor Wolfgang\\u000a Wahlster auf dem 3. Dresdner Zukunft sforum die Zukunft sversion des Internets mit den Worten: »Das Web 3.0 ist das Web 2.0\\u000a plus semantische Technologien«. Dies ist zwar eine sehr vereinfachte Darstellung, aber gerade deshalb sehr hilfreich. Eine\\u000a scharfe Trennung zwischen Web 2.0

Torsten Stapelkamp

359

Die Trimm-Aktionen des Deutschen Sportbundes zur Bewegungs- und Sportförderung in der BRD 1970 bis 1994: So ein Wurf wie der Trimmy gelingt nur einmal im Leben  

Microsoft Academic Search

Die vorliegende Studie untersucht die Trimm-Aktionen des Deutschen Sportbundes zur Bewe-gungs- und Sportförderung 1970-1994 mit dem Ziel, einen Beitrag zu der nach wie vor aktuellen Diskussion über Strategie- und Konzeptanforderungen sowie fördernde und hemmende Imple-mentations- und Wirkungsbedingungen bevölkerungsbezogener präventionspolitischer Kampag-nen zu leisten. Nach einem einführenden Überblick über den wissenschaftlichen Erkenntnisstand zum Verhältnis zwischen sportlicher Aktivität und Gesundheit sowie zu den

Verena Mörath

2005-01-01

360

Zum Ablauf des Brutgeschäftes bei Enten  

Microsoft Academic Search

Zusammenfassung 1.Fortpflanzungszeit und anschließende Großgefiedermauser nehmen bei Enten über 100 Tage in Anspruch. Spät brütende Populationen können daher in Zeitdruck kommen.2.Im Ismaninger Teichgebiet (Oberbayern) liegt der Mittelwert des Legebeginns beiAnas platyrhynchos etwa Mitte Mai,Anas strepera Ende Mai,Aythya ferina Anfang Juni undA. fuligula nach dem 10. Juni (Tab. 1). Theoretisch hätten daher die ? im Mittel erst zwischen Ende August und

Einhard Bezzel; Eberhard von Krosigk

1971-01-01

361

Schwermetalle in Federn von Habichten ( Accipiter gentilis ) aus unterschiedlich belasteten Gebieten  

Microsoft Academic Search

Zusammenfassung Mit standardisierten Habicht-Mauserfedern läßt sich die Schwermetallbelastung von Landschaftsausschnitten repräsentativ erfassen, wie der Vergleich mit auf physikalisch-technischem Weg ermittelten Depositionsraten aus dem gleichen Untersuchungsgebiet bestätigt. Zwischen den Cadmium-, Blei- und Kupfergehalten in standardisierten Habicht-Mauserfedern und den gemessenen Depositionsraten dieser Elemente besteht eine signifikante Korrelation. Die einzelnen Handschwingen zeigten unterschiedlich hohe Cadmium-, Blei- und Kupfergehalte, abhängig von ihrer Stellung im

Edmund Hahn; Karin Hahn; Markus Stoeppler

1989-01-01

362

Militär und Sozialwissenschaft – Anmerkungen zu einer ambivalenten Beziehung  

Microsoft Academic Search

\\u000a Die Befassung der Sozialwissenschaften mit der Organisation Militär reicht bis weit in die Zeit vor der Etablierung etwa von\\u000a Soziologie oder Politikwissenschaft als eigenständigen Disziplinen zurück. So verweist bereits in der Mitte des 18. Jahrhunderts\\u000a Adam Smith (1723–1790) auf die engen Beziehungen zwischen der wirtschaftlichen und sozialen Ordnung eines Staates und dem\\u000a Militär. Diesen Gedanken nimmt mehr als ein Jahrhundert

Sven Bernhard Gareis; Paul Klein

363

Funde bemerkenswerter Gefaßpflanzenarten in den Mollner Kalkvoralpen, dem mittleren Steyrtal und dem oberen Kremstal (Oberösterreich)  

Microsoft Academic Search

Records of remarkable vascular plant species in the Mollner Kalkvoralpen, the middle Steyr valley and upper Krems valley (Upper Austria) New records of 58 rare vascular plant species of the upper Krems valley, the middle Steyr valley and the adjacent Upper Austrian limestone Alps are presented. The majority of the records was made during biotope mapping-projects of the area between

F. ESSL; C. H. EICHBERGER; K. HOLBER; C. H. JUSTIN; C. OTT; A. PÜRSTINGER; G. SCHNEEWEISS; P. SCHÖNSWETTER; M. STAUDINGER; O. STÖHR; A. TRIBSCH; B. TURNER

364

"Semantische Techniken stehen kurz vor dem Durchbruch" Skepsis gegenuber dem Se  

E-print Network

.0 und Semantisches Web (oder Web 3.0) komplernentar sind . Das Web 2.0 weist eine niedrige Ein mal nicht anfangen. Das Web 3.0 setzt anfangs eine hohere Hurde, reicht aber auch wesent Iich hoher intensiveren, aber auch ertrag reicheren Web 3.0 fuhrt. e't: Der Semantie-Web-Initiative wird oftmals

van Harmelen, Frank

365

Floristische Beobachtungen aus dem östlichen Oberösterreich und dem angrenzenden Niederösterreich, Teil HI  

Microsoft Academic Search

Floristic records from eastern Upper Austria and the adjacent part of Lower Austria, Part ID New records of 100 rare vascular plant species are presented from eastern Upper Austria and the adjacent part of Lower Austria. Many of the species are aliens. The new localities are discussed with respect to relevant literature and the regional distribution of the species is

F. ESSL

366

Die Kumulation der galenischen Präparate aus Folia Digitalis purpurea und aus Folia Digitalis lanata, im Zusammenhang mit ihrem Gehalt an reinen Glykosiden  

Microsoft Academic Search

Zusammenfassung Die Kumulation der reinen Glykosidfraktionen aus Digitalis purpurea und aus Digitalis lanata wurde nach 2 Tagen bestimmt. Es zeigte sich, daß in Bezug auf diese Eigenschaft die Glykoside sich folgenderweise reihen lassen: 1. Lanatoxin, 2. Digitoxin, 3. Lanadigin, 4. Bigitalin, 5., 6. und 7.: Gitalin, Lanatalin und Glykosid IV.

R. A. Hoekstra

1932-01-01

367

Zwischen Copernicus und Kepler - M. Michael Maestlinus Mathematicus Goeppingensis 1550-1631.  

NASA Astrophysics Data System (ADS)

This book contains the written versions of talks given at a symposium held in Tübingen between 2000 October 11 - 13, and organized by the faculty of physics of Tübingen University. Michael Mästlin (1550 - 1631) was an esteemed astronomer. He was among the first who described comets as cosmic bodies, and who attempted an orbital determination. Already at an early stage, he adhered to Copernicus' heliocentric system, which he transmitted to Kepler. During 47 years, Mästlin was a professor of mathematical sciences in Tübingen, and played an outstanding role in the scientific life of his university. The contributions deal with various aspects of the life and works of Mästlin: his well-received textbook of astronomy, his role in the rejection of the 1582 calender reform by the protestants, his celestial observations, his relation to Kepler and to Galilei, his position to the progress of science of his time. Other contributions analyze contemporary attempts of the quadrature of the circle, give an overview of Mästlin's surviving published and manuscript works, and provide a vivid decription of the everyday life of a Tübingen professor around 1600. All papers are written in German, and have English abstracts.

Betsch, Gerhard; Hamel, Jürgen

368

Der Sauerstoffverbrauch von Anguilla vulgaris in seiner Abhängigkeit von Temperaturdifferenzen zwischen Kopfbereich und Rumpf  

Microsoft Academic Search

This paper is the result of an investigation into the regulation of oxygen intake in silver eels, Anguilla vulgaris L. Measurements of oxygen intake in intact and operated animals were taken both for gills and body skin. The temperatures of head and body could be varied independently from each other, so that the eels could be exposed to identical or

R. Leicht

1969-01-01

369

Paradoxien Und Die Vergegenständlichung Von Begriffen – Zu Freges Unterscheidung Zwischen Begriff – Und Gegenstand  

Microsoft Academic Search

In this paper I discuss Frege's distinction between objects and concepts and suggest a solution of Frege's paradox of the concept horse. The expression ''the concept horse'' is not eliminated and the concept is not identified with its extension, but the concept is identified with the sense of the corresponding predicate. This solution fits better into a fregean ontology and

Rosemarie Rheinwald; Gottlob Frege

1997-01-01

370

DEM Simulation of Rock Shed Failure due to Rockfall Impact  

NASA Astrophysics Data System (ADS)

The rock shed is a more costly but effective traffic facility used to keep out falling rocks in Taiwan. The main function of rock shed is to let the falling rock passing through via the top slab without hitting the road users. The failure mode of the rock shed due to rockfall impact generally includes punching of top slab, flexural cracks of beam, buckling of column, and damage of foundation, etc. Even so, the failure behavior of the rock shed is still complicated and difficult to predict. Accordingly, this study adopts the discrete element program (PFC2D) to simulate the failure behavior of rock shed. A comparison with uniaxial compression test was carried out firstly to determine the micro parameters of structure elements. The model was utilized to simulate the behavior of rock shed with impact load or hitting of falling block separately. Then, a case study of present rock shed of highway NO.18 in middle Taiwan was analyzed. The result indicates that: the primary causes of rock shed failure mode include block size, falling height, impact position, and structure system. The failure mode of punching shear failure or flexural cracks is dominated by block size and falling height. The occurrence of differential settlement is related to impact position and absence of combined footing. Considering the connection of beam and column, the structure is more likely to break at the joints rather than punching of the top slab. As a result, combined footing and beam-to-column joint should be to take into account to obtain safer protection of rock shed. Keywords: rockfall disaster, PFC, rock shed, discrete element method

Chen, Jian-An; Lin, Ming-Lang; Wang, Ching-Ping; Lo, Chia-Ming

2013-04-01

371

Enossale Implantatversorgung von Tumorpatienten mit dem Bone-Lock-System  

Microsoft Academic Search

Zusammenfassung Die implantologische Versorgung von Patienten nach ablativer Tumorchirurgie und Defektrekonstruktion erfolgt meist abseits strenger Maßstäbe der Erfolgsbeurteilung. Deshalb untersuchten wir die von Juni 1990 bis Juni 1996 bei 58 Tumorpatienten enoral gesetzten 210 Implantate regelmäßig nach. Verwendung fand ausschließlich das enossale Bone-Lock-Implantatsystem (Howmedica Leibinger GmbH, Freiburg). Untersucht wurden der Plaqueindex (Silness und Löe), der Sulkusblutungsindex (Löe), die Sondierungstiefe, die

A. Kovács; Johann Wolfgang

1998-01-01

372

DEMS 2nd, 5th and 6th period  

NSDL National Science Digital Library

Today, you are going to practice finding multiples and solving fraction problems! FIRST, you are going to help the Mayor of Pumpkinville find multiples! Begin with the number 2. You will need to collect FIVE multiples of 2 BEFORE choosing another number. Find multiples of numbers 3 through 12 before moving to the next game. GOOD LUCK! CLICK HERE --> Pumpkin Multiples Once you ...

Ms. Smith

2009-02-15

373

Die monosegmentale ventrale Spondylodese mit dem SynFix-LR™  

Microsoft Academic Search

Zusammenfassung\\u000a Hintergrund  Durch die alleinige anteriore lumbale intersomatische Fusion (ALIF) kann die Morbidität, die mit einem dorsalen Zugang verbunden\\u000a ist, vermieden werden. In dieser prospektiven Studie wurden die Ergebnisse nach monosegmentaler ventraler intersomatischer\\u000a Fusion (vF) mit einem PEEK-Cage mit integrierter winkelstabil verankerter Platte (SynFix-LR™) evaluiert.\\u000a \\u000a \\u000a \\u000a \\u000a Material und Methoden  Es wurden 32 Patienten mit Osteochondrose (L4\\/5\\/L5\\/S1) mit einer ventralen intersomatischen Fusion mittels SynFix-LR™ versorgt.

E. Hoff; P. Strube; C. Groß; T. Hartwig; M. Putzier

2010-01-01

374

Leibniz und Hannover dem Universalgenie auf der Spur  

E-print Network

Universalgenie auf der Spur Leibniz war überzeugt: Honovere heißt hohes Ufer. #12;4 5 Gottfried Wilhelm Leibniz überhaupt und Teil des Weltdokumentenerbes der UNESCO, von der Gottfried Wilhelm Leibniz Bibliothek Hannover-1784) Kupferstich von Martin Bernigeroth Gottfried Wilhelm Leibniz hat in Hannover Spuren hinterlassen. Mehrere

Vollmer, Heribert

375

Dem Generation with Short Base Length Pleiades Triplet  

NASA Astrophysics Data System (ADS)

An image triplet of Pleiades images covering the area of Zonguldak, Turkey has been investigated. The height to base relation of the first to the last image is just 1:4.5 and for the first and the second image 1:9. This is quite below the usual height to base relation of 1:1.6 for a typical stereo pair of space images. The corresponding small angle of convergence influences the possible vertical accuracy, but images with such a small angle of convergence are more similar to each other as images with larger convergence angles. This enables a better image matching, improving the vertical accuracy and compensating partially the influence of poor intersection geometry. Even over forest areas no matching gaps occurred. Height models are generated with different base configurations and compared with a reference height model. Pleiades images are distributed with 50cm ground sampling distance instead of the physical size of 70cm, the image quality justifies this zooming and also the geometric results are in the range of other space images with originally 50cm GSD. The image orientation by bias corrected Rational Polynomial Coefficients (RPC) is leading with more as 160 ground control points (GCP) to root mean square (RMS) differences slightly below 1.0 GSD of the distributed images (0.5m GSD). Only negligible systematic errors have been identified. With the combination of the first and last image a standard deviation of the generated height model of 1.6m, respectively for flat terrain close to 1.0m has been reached in relation to a reference height model. The small angle of convergence is not as much influencing the height accuracy as according to simple geometric relation.

Jacobsen, K.; Topan, H.

2015-03-01

376

Case Study: Dem Bones - Forensic Resurrection of a Skeleton  

NSDL National Science Digital Library

This is a case study for high school and undergraduate students in anatomy and physiology. In particular this case study explores anatomy of the skeleton (including landmarks), sex and age determination via pelvic and skull morphology. Users of the National Center for Case Study Teaching in Science will be required to register (free) to gain access to the answer key (and must be of teaching status to receive the key). Included in the resource are the case overview, objectives, case study, teaching notes and answer key.

Alease S. Bruce (University of Massachusetts-Lowell Department of Health and Clinical Sciences)

2001-07-09

377

DEM Solutions Develops Answers to Modeling Lunar Dust and Regolith  

NASA Technical Reports Server (NTRS)

With the proposed return to the Moon, scientists like NASA-KSC's Dr. Calle are concerned for a number of reasons. We will be staying longer on the planet's surface, future missions may include dust-raising activities, such as excavation and handling of lunar soil and rock, and we will be sending robotic instruments to do much of the work for us. Understanding more about the chemical and physical properties of lunar dust, how dust particles interact with each other and with equipment surfaces and the role of static electricity build-up on dust particles in the low-humidity lunar environment is imperative to the development of technologies for removing and preventing dust accumulation, and successfully handling lunar regolith. Dr. Calle is currently working on the problems of the electrostatic phenomena of granular and bulk materials as they apply to planetary surfaces, particularly to those of Mars and the Moon, and is heavily involved in developing instrumentation for future planetary missions. With this end in view, the NASA Kennedy Space Center's Innovative Partnerships Program Office partnered with OEM Solutions, Inc. OEM Solutions is a global leader in particle dynamics simulation software, providing custom solutions for use in tackling tough design and process problems related to bulk solids handling. Customers in industries such as pharmaceutical, chemical, mineral, and materials processing as well as oil and gas production, agricultural and construction, and geo-technical engineering use OEM Solutions' EDEM(TradeMark) software to improve the design and operation of their equipment while reducing development costs, time-to-market and operational risk. EDEM is the world's first general-purpose computer-aided engineering (CAE) tool to use state-of-the-art discrete element modeling technology for the simulation and analysis of particle handling and manufacturing operations. With EDEM you'can quickly and easily create a parameterized model of your granular solids system. Computer-aided design (CAD) models of real particles can be imported to obtain an accurate representation of their shape. EDEM(TradeMark) uses particle-scale behavior models to simulate bulk solids behavior. In addition to particle size and shape, the models can account for physical properties of particles along with interaction between particles and with equipment surfaces and surrounding media, as needed to define the physics of a particular process.

Dunn, Carol Anne; Calle, Carlos; LaRoche, Richard D.

2010-01-01

378

A DEM model for contact electrification of irregular shaped particles  

NASA Astrophysics Data System (ADS)

Contact electrification may occur during particle-particle and particle-wall collisions due to the contact potential difference. The aim of the current work is to examine the effect of particle shape on contact electrification. A discrete element method was developed to model irregular shaped particles with a multi-sphere representation and to analyse contact electrification using a condenser model. The irregular particles were modelled with a row of clustered primary spheres of various sizes and were characterized using a radial shape index that is defined as the ratio of the size between the distal and central spheres. They were subjected to tribo-electrification in a vertically vibrating container. It was revealed that the charging processes and charge distributions with different radial shape indexes exhibited distinct patterns. Specifically, particles with a large radial shape index acquired higher charge on the distal primary spheres whilst those with a smaller radial shape index gained more charge in the centre. This is due to the difference in contact probabilities associated with non-spherical particles, which leads to non-uniform charge distributions.

Pei, Chunlei; Wu, Chuan-Yu; Adams, Michael; England, David; Byard, Stephen; Berchtold, Harald

2013-06-01

379

BUILDING EXTRACTION USING LIDAR DEMS AND IKONOS IMAGES  

Microsoft Academic Search

An automated method for boundary representation of building objects has been considered as a core processor for 3D city modelling. Since the reconstruction of generic building shape fundamentally depends on geometric features extracted from data sources, it suffers difficulties especially when a monocular imagery with high scene complexity is solely used. The research described in this paper aims to develop

G. Sohn; I. Dowman

380

DEM modeling of fracture propagation in veined rock  

NASA Astrophysics Data System (ADS)

One fundamental aspect of crack seal veins is that an existing vein can act as a heterogeneity in the rock which controls the localization of successive fracturing at unchanged mean stress orientations. Observations from crack-seal vein systems suggest that existing veins fundamentally influence the fracture behavior of a rock even in cases where the orientation of the stress field is highly incompatible with the orientation of the vein. We used a series of 3D Discrete Element Simulations to systematically investigate the influence of existing veins with varying orientation and mechanical properties on an approaching fracture. The models consist of a tabular heterogeneity within a bonded particle volume fractured under uniaxial tension. The parameters varied in the study are the orientation of the heterogeneity relative to the direction of uniaxial extension and therefore relative to the orientation of the favorable fracture plane as well as the fracture strength ratio between the matrix material, the vein material and the interface between vein and matrix material. The elastic parameters (e.g. Young's modulus) are kept homogeneous throughout the model. Thereby it is ensured that the results are not altered by stress field perturbation induced by stiffness contrasts. The model materials used were carefully tested and calibrated to ensure comparability with natural examples in terms of their fracture-mechanical properties. The simulations were repeated for several random particle packings to eliminate the effect of heterogeneities in the packing on the results. The results show a strong influence of the tabular heterogeneity on the fracture propagation for all orientations and at cohesion ratios within the range of natural systems. Besides curving and deflection of the fracture path associated with changes in fracture mode, bifurcation of fractures as well as arrest of propagation and nucleation of new fractures can be observed.

Virgo, S.; Abe, S.; Urai, J. L.

2012-04-01

381

Zur Theorie der Manganate Auf dem Weg zu neuer Elektronik  

E-print Network

wissenschaftliche Abhandlung 1600 von Sir William Gilbert heute: kollektive Anordnung von Elektronenspins trotz in China erste wissenschaftliche Abhandlung 1600 von Sir William Gilbert heute: kollektive Anordnung von

Peters, Achim

382

Interpolation of phenological phases on a digital elevation model (DEM)  

NASA Astrophysics Data System (ADS)

The main objective of the VegDyn project (a cooperation between Joanneum Research, Institute of Digital Image Processing, LFZ Raumberg-Gumpenstein and ZAMG) consists in quantifying and modelling the relationship between individual growth stages of grassland on the one hand and atmospheric parameters, remotely sensed data and phenological observations on the other. The model simulates the beginning and the end of the vegetation period and the growth stages of grassland with temperature as input variable. Thus it will be possible to explore changes of the timing of the vegetation period and the growth stages of grassland in possible future climate scenarios, which are calculated by climate models. In the context of the VegDyn project we developed methods for the spatial interpolation of phenological phases on a digital elevation model with a 250 m grid resolution in the complex terrain of the Alps. The final result is a series of maps of long term mean entry dates and maps of entry dates of individual years, which can for instance be related with the Net Difference Vegetation Index (NDVI) parameter maps from satellite observations. Apart from the yearly input via the conventional observational network based on voluntary observers and the input via the web interface, the Austrian phenological data base is still being supplemented by data from the paper archive. The elevation of the station network ranges from 100 to 1700 m. The station density can reach up to 100 or more stations per phase and season during 1951 - 2009. From more than 280 observed phases including phases from wild (woody and herbaceous) and agricultural plants those have been selected, which are related to cultivated grassland and which can be detected by remote sensing. In order to be selected for spatial interpolation the phase must satisfy a number of criteria: a minimum number of stations and, in order to have a meaningful long term mean entry date, a minimum number of observations per station during 1951 - 2009. If this minimum number is set to 20 years, there remain averagely 129 stations per phase, which fulfil the criterion. An average observer notes about 51 phases. This results in a rather high year to year fluctuation of observing stations and observed phases. The applied interpolation methods are linear regression with the entry dates as dependent and the station coordinates as independent variables, height reduced inverse distance weighting, and height reduced mean. For the latter two methods the search radius and the number of selected nearest neighbouring stations for interpolation have been optimised via trial and error. Interpolation quality is being checked via spatial cross validation, where the average anomaly, explained spatial variance (correlation squared or RSQ) and the root mean squared error (RMSE) serve as quality criteria. The resulting set of maps contains the interpolated long term mean phenological entry date and the entry dates of a series of individual years (1990 - 2009) for each of the three methods. This enables a comparison of the three interpolation methods and an evaluation of the quality of the results.

Schöngaßner, Thomas C.; Scheifinger, Helfried

2010-05-01

383

7.5-Minute Digital Elevation Model (DEM)  

NSDL National Science Digital Library

The US Geological Survey (USGS) performs a wide variety of tasks related to the environment including data acquisition for use in geographical information systems. This data set provides elevation data for the contiguous US, Hawaii, and Alaska. Data are in one-by-one degree blocks and available via an online interface or by ftp download (instructions provided in the User Guide). Specific data can be located via alphabetical list, state, or a graphic of the US.

384

ASTER DEMs for geomatic and geoscientific applications: a review  

Microsoft Academic Search

Most geoscientific applications using georeferenced cartographic\\/geospatial data require good knowledge and visualization of the topography of the Earth's surface. For example, mapping of geomorphological features is hardly feasible from a single image; three?dimensional (3D) information has to be generated or added for a better interpretation of the two?dimensional data. Since the early emergence of earth observation satellites, researchers have investigated

Thierry Toutin

2008-01-01

385

Wanderverhalten von Nonnenraupen unter dem Einflß von Metalleffekten  

Microsoft Academic Search

Investigations were made on migration-behaviour of caterpillars ofLymantria monacha influenced by pure metals, whose effects together with those of electric-magnetical powers are normally effective inside of zones of earth radiatons in fields. It was ascertained, that attraction of food, lying in different distances from the metals varied between normal zones and zones of earth-radiations. Inside of zones of earth-radiations the

Else Jahn

1984-01-01

386

Forecasting of Storm Surge Floods Using ADCIRC and Optimized DEMs  

NASA Technical Reports Server (NTRS)

Increasing the accuracy of storm surge flood forecasts is essential for improving preparedness for hurricanes and other severe storms and, in particular, for optimizing evacuation scenarios. An interactive database, developed by WorldWinds, Inc., contains atlases of storm surge flood levels for the Louisiana/Mississippi gulf coast region. These atlases were developed to improve forecasting of flooding along the coastline and estuaries and in adjacent inland areas. Storm surge heights depend on a complex interaction of several factors, including: storm size, central minimum pressure, forward speed of motion, bottom topography near the point of landfall, astronomical tides, and most importantly, maximum wind speed. The information in the atlases was generated in over 100 computational simulations, partly by use of a parallel-processing version of the ADvanced CIRCulation (ADCIRC) model. ADCIRC is a nonlinear computational model of hydrodynamics, developed by the U.S. Army Corps of Engineers and the US Navy, as a family of two- and three-dimensional finite element based codes. It affords a capability for simulating tidal circulation and storm surge propagation over very large computational domains, while simultaneously providing high-resolution output in areas of complex shoreline and bathymetry. The ADCIRC finite-element grid for this project covered the Gulf of Mexico and contiguous basins, extending into the deep Atlantic Ocean with progressively higher resolution approaching the study area. The advantage of using ADCIRC over other storm surge models, such as SLOSH, is that input conditions can include all or part of wind stress, tides, wave stress, and river discharge, which serve to make the model output more accurate.

Valenti, Elizabeth; Fitzpatrick, Patrick

2005-01-01

387

Natural Neighbor Interpolation Based Grid DEM Construction Using a GPU  

E-print Network

-tenth of the time required for the same computer to perform a standard linear interpolation, which produces a much otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission-1-4503-0031-5 ...$10.00. seen in a simple flood mapping application. Figure 1(b,c) shows the result of the flood risk

Agarwal, Pankaj K.

388

An Investigation of Flare Footpoint DEMs using AIA Diffraction Patterns  

NASA Astrophysics Data System (ADS)

The heating of flare footpoints by accelerated electrons is a well-established component of the standard flare model. However, limitations of current instruments make it challenging to obtain high cadence, high resolution observations of the brightest footpoint regions, predominantly due to low cadence, or pixel saturation.In moderate and large flares observed by the Solar Dynamics Observatory’s Atmospheric Imaging Assembly, CCD pixels in the footpoint regions are frequently saturated despite the automatic exposure control. Using the method of Schwartz et al. (2014), we reconstruct saturated footpoint kernels in the brightest flaring regions and investigate the evolving footpoint differential emission measure at the full 12 second AIA cadence. This is compared to the changing electron fluxes observed with the Reuven Ramaty Solar Spectroscopic Imager (RHESSI) to investigate the relationship between the non-thermal electron energy flux and the footpoint thermal response.(Schwartz, R. A., Torre, G., & Piana, M. (2014), Astrophysical Journal Letters, 793, LL23 )

Raftery, Claire; Bain, Hazel; Schwartz, Richard; Torre, Gabriele; Krucker, Sam

2015-04-01

389

FORTSCHRITTE AUF DEM GEBIET DER HONIGTAU-FORSCHUNG  

E-print Network

the honeydew from only few (58 known) species of Ster- norrhyncha (coccids, aphids, psyllids) (Table 1. As a consequence, these aphids secret 2-3 times more honeydew with 25-40% dry weight sucrose (from coccids and aphids) instead of less than 1 % sucrose found from aphids without a filter - gut. The appearance

Paris-Sud XI, Université de

390

Digital elevation models (DEMs) are representations of topog-raphy with inherent errors that constitute uncertainty. DEM  

E-print Network

percent, 460 to 950 percent for derived catchment areas and 4 to 9 percent for the topographic index direction, which are used to identify ridges and valleys and derive the topographic index, a statistic: slope, upslope contributing area and topographic index (TI). This methodology could also be applied

Kroll, Charles Nathan

391

Letale Kardiomyopathie bei adulter Polyglukosankörperkrankheit  

Microsoft Academic Search

Zusammenfassung  \\u000a Der seltenen adulten Polyglukosankrperkrankheit (APBD) liegen autosomal-rezessiv vererbte Defekte des Glykogen-Branching-Enzyms\\u000a zugrunde. Die Erkrankung wird meist zwischen dem 40. und 60. Lebensjahr klinisch manifest und verluft langsam progredient.\\u000a Pathologisch-anatomisch knnen charakteristische globulre Ablagerungen (Polyglukosankrper, PGK) in Biopsaten von Haut, Muskulatur\\u000a und peripheren Nerven sowie im Zentralnervensystem nachgewiesen werden. Diese bestehen biochemisch aus verzweigungsarmen Glykogenmoleklen\\u000a mit pathologisch langen einzelnen Polysaccharidketten.

E. Postler; E. Sindern; M. Vorgerd; I. Schmitz; J. P. Malin; K. M. Müller

2002-01-01

392

Kassette oder Spule? Die Compactkassette zwischen Anspruch und Wirklichkeit. (Cassette or Reel? The Compact Cassette between Claims and Reality).  

ERIC Educational Resources Information Center

Discusses the use of compact cassettes in the context of individualized foreign language teaching in laboratory work at the university level. Presents and comments on some technical data regarding the relative merits of cassettes v reels. (IFS/WGA)

Jung, Udo O. H.

1979-01-01

393

Charakterisierung von Sulfotransferasen im Gastrointestinaltrakt von Mensch und Ratte und Aktivierung von Promutagenen in V79-Zellen, die eine intestinale Form (1B1) des Menschen und der Ratte exprimieren  

NASA Astrophysics Data System (ADS)

Die Ausstattung der gastrointestinalen Mukosa des Menschen und der Ratte mit Sulfotransferasen wurde mit Hilfe von Immunodetektion und Enzymaktivitätsmessungen untersucht. In Proben aus Colon und Rektum von 39 Personen wurden die Formen h1A1, h1A3 und h1B1 identifiziert, wobei in einer weiteren Probe, die als einzige von einem an Colitis Ulcerosa erkrankten Patienten stammte, keine Sulfotransferasen nachgewiesen werden konnten. Bei der Immunblot-Analyse war das Expressionsmuster der einzelnen Formen in allen Proben ähnlich. In wenigen Proben waren die relativen Signalintensitäten der h1A1 und der h1B1 um die Hälfte erniedrigt. Der Gehalt von SULT an zytosolischem Protein zeigte einen bis zu 8 - 10fachen Unterschied, er betrug jedoch bei zwei Dritteln der Proben zwischen 0,15 und 0,3 (h1A1 und h1A3) bzw. 0,6 und 0,8 Promille (h1B1). Die Variation konnte nicht auf Alter, Geschlecht oder Krankheitsbild der Patienten zurückgeführt werden. Auch der für die allelischen Varianten der h1A1 beschriebene Effekt auf die Enzymaktiviät bzw. Stabilität konnte in der Menge an immunreaktivem Protein nicht in diesem Ausma detektiert werden. Die Allelhäufigkeit von h1A1*R und h1A1*H war gegenüber der gesunden Bevölkerung nicht verändert. In den sieben Proben aus dem Dünndarm (Coecum, viermal Ileum, Jejunum) konnten zusätzlich die Formen h1E1 und h2A1 identifiziert werden. Ein möglicherweise der Form h1C1 entsprechendes Protein wurde im Magen detektiert. Im Vergleich zum Menschen war die Expression in der Ratte stärker auf die Leber konzentriert. Während beim Menschen in allen untersuchten Abschnitten Sulfotransferasen in Mengen detektiert wurden, die in zwei Fällen (h1B1 und h1A3) sogar den Gehalt in der Leber überstiegen, beschränkte sich die Expression in der Ratte auf im Vergleich zur Leber geringe Mengen im Magen und Dickdarm. Nachgewiesen wurden die r1B1, r1A1 sowie eine nicht identifizierte Form von 35kD, bei der es sich vermutlich um die r1C2 handelt. Im Vergleich zur Leber enthielt der Dickdarm der Ratte 20 - 30 % an r1B1 und 3 % an r1A1, während im Dickdarm des Menschen die 3 - 5fache Menge an h1B1 und 25 - 50 % an h1A1 gefunden wurden. Die nicht identifizierte Form verhielt sich wie die r1B1. Die für die Leber der Ratte bekannte geschlechtsabhängige Expression wurde im Gastrointestinaltrakt nicht beobachtet. Die Verteilung der Sulfotransferasen im Colon und Ileum des Menschen wurde immunhistochemisch untersucht; für die Gewebe der Ratte war die Spezifität der zur Verfügung stehenden Antiseren nicht ausreichend. Im Colon traten h1B1-spezifische Färbungen in den differenzierten Enterozyten am oberen Ende der Krypten auf, im Dünndarm wurden die Epithelzellen der Zotten gefärbt. Die Färbung konzentrierte sich auf das Zytoplasma. Eine ähnliche Verteilung zeigte sich für h1A1 und h1A3, auer da zusätzlich eine intensive Färbung der Endothelzellen der Kapillaren in der Submukosa des Ileums auftrat. Im Dickdarm war dies nur bei den Kapillaren in den Lymphfollikeln zu erkennen. Die h2A1 war lediglich im Zytoplasma der Epithelzellen der Zotten des Ileums nachzuweisen, während im Colon keine Farbreaktion auftrat. Durch die Verwendung der rekombinanten Indikatorstämme TA1538-h1A1, -h1A3 und -h1B1 und des Ausgangsstammes Salmonella typhimurium TA1538 im Ames-Test wurde gezeigt, da verschiedene benzylische und allylische Alkohole durch im humanen Colon exprimierte Sulfotransferasen zu Mutagenen aktiviert werden. In den meisten Fällen erwies sich eine der drei Sulfotransferasen als besonders effizient in der Bioaktivierung, während durch die anderen Formen kein oder nur ein schwacher Effekt verursacht wurde. Die Bioaktivierung von Promutagenen durch Sulfotransferasen im Colon mu im Zusammenhang mit der Lokalisation diskutiert werden. Die Zellen im Darm, in denen immunhistochemisch Sulfotransferasen detektiert wurden, haben mit Ausnahme des Endothels je nach Abschnitt eine Lebensdauer von maximal fünf Tagen und machen keine weiteren Zellteilungen mehr durch. Daher sind DNA-Schäden in diesen Zellen ein seh

Teubner, Wera

2001-05-01

394

An erudite between the worlds: Gottfried Kirch and his visions of the Enlightenment (German Title: Ein Gelehrter zwischen den Welten: Gottfried Kirch und seine aufklärerischen Visionen)  

NASA Astrophysics Data System (ADS)

The calendar literature, until now not held in high esteem by research, had an important share in the dissemination of the enlightenment already in the 1670s. This contentual orientation was especially pronounced in the calendars of Gottfried Kirch. The widely used calendars by Kirch are analyzed in this contribution.

Herbst, Klaus-Dieter

2010-12-01

395

Zwischen Wollen, aber nicht können und Können, aber nicht wollen: Übergangsprobleme von Jugendlichen in Japan am Beispiel der „Freeter`` und „NEETs``  

NASA Astrophysics Data System (ADS)

Caught between wanting but not being able to, and being able, but not wanting to: Transitional problems among Japanese youths based on the examples of "Freeters" and "NEETs" - The study of processes of transition from the education system to employment is particularly important in light of youth unemployment. In Japan this transition process is often declared to be successful. In recent years, however, numerous signs have indicated a change in the situation. This article analyses this problem based on the examples of two Japanese social groups, "Freeters" and "NEETs". These terms refer to young adults who do not immediately move into to regular employment. The article begins by analysing the causes, then comments on education policy measures undertaken to tackle the issue. Drawing on scientifically grounded models it is shown that both social groups are characterised by meagre formal school qualifications. Social background, by contrast, is not particularly relevant; although there are hints that parents' financial means play an increasingly important role in determining whether a young person attends a high-level educational institution. Although public opinion in Japan frequently attributes values and attitudes to these groups that deviate from the norm, this is not conclusively supported by existing empirical findings. Consequently, the reasons for these transitional problems tend to be perceived as being connected to the difficult labour market situation resulting from the ongoing economic crisis. In addition to certain education policy initiatives, Japan will therefore rely heavily in future on the ability to effectively manage the integration of its shrinking cohorts of school and university graduates.

Eswein, Mikiko; Pilz, Matthias

2012-08-01

396

A review of "Orthodoxie als Konsensbildung. Das theologische Disputationswesen an der Universitat Wittenberg zwischen 1570 und 1710" by Kenneth G. Appold  

E-print Network

. Appold aims to examine the applicability of the confessionalization the- sis; to study late-sixteenth- and early-seventeenth-century orthodox Lutheran ecclesiology; and to rehabilitate study of university elites against a research agenda currently much... more occupied with popular piety and territorial poli- tics. Most importantly, however, as signalled by the order of his arguments, he seeks to argue against a still-common stereotype of sixteenth- and seven- teenth-century Lutheran theological...

Boettcher, Susan R.

2007-01-01

397

"Astronomica" in the Correspondence between Leonhard Euler and Daniel Bernoull (German Title: "Astronomica" im Briefwechsel zwischen Leonhard Euler und Daniel Bernoulli)  

NASA Astrophysics Data System (ADS)

The Euler Commission of the Swiss Academy of Sciences intends to terminate the edition of Leonhard Euler's works in the next year 2011 after nearly one hundred years since the beginning of the editorial works. These works include, e.g., Volume 3 of the Series quarta A which will contain the correspondence between Leonhard Euler (1707-1783) and Daniel Bernoulli (1700-1783) and which is currently being edited by Dr. Emil A. Fellmann (Basel) and Prof. Dr. Gleb K. Mikhailov (Moscow). This correspondence contains more than hundred letters, principally from Daniel Bernoulli to Euler. Parts of this correspondence were published uncommented already in 1843. It is astonishing that, apart from mathematics and physics (mainly mechanics and hydrodynamics), many topics addressed concern astronomy. The major part of the preserved correspondence between Euler and Daniel Bernoulli, in which astronomical themes are discussed, concerns celestial mechanics as the dominant discipline of theoretical astronomy of the eighteenth century. It was triggered and coined mainly by the prize questions of the Paris Academy of Science. In more than two thirds of the letters current problems and questions concerning celestial mechanics of that time are treated, focusing on the lunar theory and the great inequality in the motions of Jupiter and Saturn as special applications of the three body problem. In the remaining letters, problems concerning spherical astronomy are solved and attempts are made to explain certain phenomena in the field of "cosmic physics" concerning astronomical observations.

Verdun, Andreas

2010-12-01

398

A Study of the Novel of Otto Ludwig based on “Maria,” “Die Heiterethei u. i Widerspiel” and “Zwischen Himmel u. Erde”  

E-print Network

to a "Schwarz- wfllder Uhr"; "Wie sie daher kam g l i c h sie einer rückwärts wandeln­ den SchwarzwÄlder Uhr an der das Haubenfleckchen,das Z i f f e r b l a t t , die lang von der zuckerhut^förmigen schwarzen Haube i n den Rücken hinabfallenden...-Lieb sah si c h wichtig um und schwieg, b i s d i e V a l t i n e s s i n - 20 - l i e Habe warf und demit erklärte, ale halte den Adams-Lieb weder fur einen Schwarzwälder noch für einen salfeder, X X X da begann er: X X X X X X X X X X X X Der Schmied...

Palmer, Emma Mae

1909-01-01

399

Zwischen Gesetz und Fall. Mutmassungen uber Typologien als Padagogische Wissensform (Between General Law and the Individual Case. Conjectures Concerning Typologies as a Form of Pedagogical Knowledge).  

ERIC Educational Resources Information Center

Considers the mediation between scientific knowledge and practical action as a crucial feature of professional teaching. Investigates the assumption that typologies represent a form of knowledge which can bridge the gap between theory and practice. Differentiates between two forms of typological thinking and discusses reservations concerning…

Herzog, Walter

2003-01-01

400

Reduzierung der Wasserbeanspruchung durch Dränung  

NASA Astrophysics Data System (ADS)

In das Erdreich einbindende Teile von Bauwerken müssen in aller Regel gegen den Zutritt von im Boden vorhandenen Wasser geschützt werden. In der Abdichtungstechnik wird zwischen den Beanspruchungen drückendes Wasser, nichtdrückendes Wasser und Bodenfeuchte/nichtstauendes Sickerwasser unterschieden. Liegt der Grundwasserspiegel ständig oberhalb der Bauwerkssohle, so muss eine vergleichsweise aufwendige Abdichtung von Sohle und Kelleraußenwänden gegen drückendes Wasser vorgesehen werden, da eine dauerhafte Grundwasserabsenkung generell unzulässig ist. Auch wenn der ständige Grundwasserspiegel unterhalb der Bauwerkssohle liegt, ist jedoch bei Vorhandensein schwach durchlässiger Böden mit dem temporären Auftreten von drückendem Wasser zu rechnen, welches als Stau- oder Schichtenwasser auftritt. In solchen Fällen kann die Wasserbeanspruchung des Bauwerks durch Anordnung einer Dränanlage reduziert werden, so dass eine Abdichtung gegen Bodenfeuchte/nichtstauendes Sickerwasser (bei Kellerwänden und Sohlplatten) bzw. gegen nichtdrückendes Wasser (bei erdüberschütteten Decken) ausreichend ist (Bild 4.1).

Achmus, Martin

401

Toxikologie der synthetischen Antioxidantien BHA und BHT im Vergleich mit dem natürlichen Antioxidans Vitamin E  

Microsoft Academic Search

The toxicology of the food preservatives butylhydroxyanisole (BHA) and butylhydroxytoluene (BHT) as well as the naturally occurring vitamin E (a-tocopherol) is described. In high dosages all three compounds induce in animals impairment of blood clotting, which can be explained by an antagonism with vitamin K. Specific toxic effects to the lung have only been observed with BHT. The other described

Regine Kahl; Hermann Kappus

1993-01-01

402

A DEM-based Watershed Model with Spatial Hortonian Infiltration and Ruh-Off/On  

Technology Transfer Automated Retrieval System (TEKTRAN)

A physically based, distributed rainfall-runoff-runon model was developed for event-based studies of dynamic watershed processes, including space-time patterns of state variables (e.g., soil profile water storage) and fluxes (e.g., overland flow and infiltration). A routing hierarchy for dynamic ru...

403

Call for a Joint Master thesis: Cohesive powder (Regolith) properties by DEM simulations  

E-print Network

/Churyumov- Gerasimenko. From this event, measurements of the mechanical properties of the comet "soil" will be available is known about the mechanical properties of comet material, while lunar regolith has been characterized in space. It includes dust, soil, broken rock, and other related materials and is present on Earth

Al Hanbali, Ahmad

404

Spatial statistical properties and scale transform analyses on the topographic index derived from DEMs in China  

Microsoft Academic Search

The topographic index (TI), frequently used in approximately characterizing the spatial distribution of variable source areas within a watershed, has been widely applied in topography-based land-surface process schemes coupled in regional or global climatic models. The TI concept, however, was originally developed for studying hill-slope scale hydrological processes and was most commonly used in simulations from small- to medium-sized watersheds.

Bin Yong; Wan-Chang Zhang; Guo-Yue Niu; Li-Liang Ren; Cheng-Zhi Qin

2009-01-01

405

Components of uncertainty in primary production model: the study of DEM, classification and location error  

Microsoft Academic Search

The use of geographic information system (GIS)-based ecological models is increasing and input datasets of these models are improving daily. Still, there is a notable gap in quantifying the uncertainty related to these models. Quantifying uncertainty in spatial ecology is indeed crucial because it may improve the support that GIS provides for decision support systems. This article aims to quantify

E. Livne; T. Svoray

2011-01-01

406

Paroodectes feisti , der erste Miacide (Carnivora, Mammalia) aus dem Mittel-Eozän von Messel  

Microsoft Academic Search

\\u000a Abstract  From the Middle Eocene (Lower Lutetian) Oil Shale of Messel near Darmstadt (South-Hesse) the first completely preserved Miacid\\u000a is described. The systematic position of the Miacidae is discussed before. A short review of the paleogeographic (North-America,\\u000a Eurasia) and stratigraphic (L. Paleocene — U. Eocene, ? U. Oligocene) distribution is given; the fossil record of European\\u000a species is more detailed. The

Rainer Springhorn

1980-01-01

407

Dynamic simulations of geologic materials using combined FEM/DEM/SPH analysis  

SciTech Connect

An overview of the Lawrence Discrete Element Code (LDEC) is presented, and results from a study investigating the effect of explosive and impact loading on geologic materials using the Livermore Distinct Element Code (LDEC) are detailed. LDEC was initially developed to simulate tunnels and other structures in jointed rock masses using large numbers of polyhedral blocks. Many geophysical applications, such as projectile penetration into rock, concrete targets, and boulder fields, require a combination of continuum and discrete methods in order to predict the formation and interaction of the fragments produced. In an effort to model this class of problems, LDEC now includes implementations of Cosserat point theory and cohesive elements. This approach directly simulates the transition from continuum to discontinuum behavior, thereby allowing for dynamic fracture within a combined finite element/discrete element framework. In addition, there are many application involving geologic materials where fluid-structure interaction is important. To facilitate solution of this class of problems a Smooth Particle Hydrodynamics (SPH) capability has been incorporated into LDEC to simulate fully coupled systems involving geologic materials and a saturating fluid. We will present results from a study of a broad range of geomechanical problems that exercise the various components of LDEC in isolation and in tandem.

Morris, J P; Johnson, S M

2008-03-26

408

CampusHD0313 + + + + + Frhlingsgefhle wecken... mit dem Lieblingsrezept zum Nachkochen + + + + +  

E-print Network

2 Tel: 06221. 54 37 50 E-Mail: pbs@stw.uni-heidelberg.de Anmeldung und Terminvereinbarung Mo - Do 8. 54 37 58 E-Mail: sozb@stw.uni-heidelberg.de Persönliche Termine sind nach Vereinbarung möglich: 06221. 54 34 98 E-Mail: kitav@stw.uni-heidelberg.de Sprechzeiten: Mo - Do 9.30 - 12.00 Uhr und nach

409

Numerical simulation of grate firing systems using a coupled CFD\\/discrete element method (DEM)  

Microsoft Academic Search

The objective of this study is to simulate the motion and chemical conversion of solid fuels in a packed bed moving on a forward acting grate. The approach considers a packed bed to be composed of a large number of individual (currently spherical) particles, which have different properties and sizes. Each of these particles undergoes a sequence of processes such

E. Simsek; B. Brosch; S. Wirtz; V. Scherer; F. Krüll

2009-01-01

410

CFD-DEM modelling of multiphase flow in dense medium cyclones  

Microsoft Academic Search

Dense medium cyclone (DMC) is a high-tonnage device that is widely used to upgrade run-of-mine coal in coal preparation. It is simple in design but the flow pattern within it is complex due to the size and density distributions of the feed and process medium solids, and the turbulent vortex formed. This paper presents a mathematical model to describe this

K. W. Chu; B. Wang; A. B. Yu; A. Vince

2009-01-01

411

DEM analyses and morphotectonic interpretation: The Plio-Quaternary evolution of the eastern Ligurian Alps, Italy  

NASA Astrophysics Data System (ADS)

The Ligurian Alps (Italy) straddle a complex and ill-defined tectonic transition that accommodates Eurasia-Adria shortening driving concurrent growth of the western Alps and northern Apennines. We focus on the Plio-Quaternary landscape evolution of the eastern part of the Ligurian Alps with the goal of defining the active tectonics through an analysis of topography, drainage networks, and river long profiles. The Ligurian Alps have a steep, seaward-facing escarpment with topographic features reminiscent of the geomorphic markers preserved on both actively-uplifting coastlines and passive margins. For example, there are seaward-facing benches that are thought to be uplifted marine terraces common to active margins; but the drainage divide of the seaward escarpment shows clear evidence of recent northward migration into the Po foreland, a process consistent with escarpment retreat characteristic of passive or subsiding margins. This study explores the active tectonics consistent with these diverse landscape evolution pathways. Our analysis reveals that rock-type strongly throttles the development of topographic relief, drainage networks, and northward migration of the drainage divide. However, we also identify segments of the escarpment that indicate recent base level falls through an analysis of modeled channel steepness and comparison with mean hillslope gradient. The base level falls are consistent with numerous barbed tributaries that are best explained as recent stream captures. No significant correlation among the stream captures at the drainage divide, suspected marine terraces at the coast, Ligurian Sea bathymetry, and active seismicity indicates that the escarpment is the footwall of a segmented normal fault. This normal fault is embedded in a regionally subsiding margin where actively uplifting segments lead to a straightened, pinned drainage divide, whereas, relatively inactive segments permit divide migration into the footwall block. These results are broadly consistent with rock uplift increasing eastward toward Genova across the long-suspected Alps-Apennine Sestri-Voltaggio fault zone. They highlight the respective roles of legacy structures, rock-type, and localized rock uplift in constructing a landscape in an otherwise extending and subsiding crustal retrowedge of an active subduction plate boundary.

Ferraris, Francesca; Firpo, Marco; Pazzaglia, Frank J.

2012-05-01

412

Statistical texture for contour interval choice of 1:50,000 DEMs  

NASA Astrophysics Data System (ADS)

How to choose contour interval in different geomorphologic type areas is a challenging job. In the paper a statistical texture method is used to measure the distance between Loess Hillock and Loess Ridge in Loess Plateau, which geomorphologic types are hills. The result shows that when the two areas classified into 25 classes or so with the contour interval 15 and 19 individually, the class separability seems more distinct than less than 25 classes. The results also shows that when the number of class is bigger than 25, the class separability decrease instead of increasing correspondingly. It seems that the too many classes used may produce more details in cost of decreasing class separability. And in the seven statistical variables, the number of polygons is the most stable while the mean grayscale, the standard variation of grayscale are the most sensitive when the contour interval changes. The result indicates that the contour interval mainly influences by elevation and relative relief without more information which being dominant. By aid of an appropriate contour interval, the landform features can be easily extracted and is very helpful in delaminate the topography.

Luo, MingLiang; Tang, Guoan; Yan, Shijiang; Dong, Youfu

2008-10-01

413

Statistical texture for contour interval choice of 1:50,000 DEMs  

NASA Astrophysics Data System (ADS)

How to choose contour interval in different geomorphologic type areas is a challenging job. In the paper a statistical texture method is used to measure the distance between Loess Hillock and Loess Ridge in Loess Plateau, which geomorphologic types are hills. The result shows that when the two areas classified into 25 classes or so with the contour interval 15 and 19 individually, the class separability seems more distinct than less than 25 classes. The results also shows that when the number of class is bigger than 25, the class separability decrease instead of increasing correspondingly. It seems that the too many classes used may produce more details in cost of decreasing class separability. And in the seven statistical variables, the number of polygons is the most stable while the mean grayscale, the standard variation of grayscale are the most sensitive when the contour interval changes. The result indicates that the contour interval mainly influences by elevation and relative relief without more information which being dominant. By aid of an appropriate contour interval, the landform features can be easily extracted and is very helpful in delaminate the topography.

Luo, MingLiang; Tang, Guoan; Yan, Shijiang; Dong, Youfu

2009-10-01

414

Die intramedulläre Osteosynthese der pertrochantären Femurfraktur mit dem proximalen Femurnagel (PFN)  

Microsoft Academic Search

Zusammenfassung Operationsziel Primär belastungsstabile, möglichst wenig invasive Osteosynthese aller per- und subtrochantären Femurfrakturen. Rasche Wiederherstellung der Form und Funktion der Gliedmaße. Indikationen Sämtliche per- und subtrochantären Frakturen der AOKlassifikation 31.A. Bei Kombinationen von Schenkelhals- und pertrochantären Femurfrakturen mit Femurschaftfrakturen sowie bei proximalenFemurschaftfrakturen ist die Verwendung eines überlangen proximalen Femurnagels (PFN) möglich. Kontraindikationen Ausgeprägte ipsilaterale Koxarthrose. Offene Wachstumsfugen. Operationstechnik Intramedulläre Nagelung,

Akhil P. Verheyden; Christoph Josten

2003-01-01

415

Analysis of volumetric scatters based on TanDEM-X polarimetric interferometric SAR data  

Microsoft Academic Search

Polarimetric SAR Interferometry makes possible a detailed analysis of the volumetric scattering processes present in microwave scattering in case of forest areas. In previous contributions, the authors, under the hypothesis of the RVoG coherent scattering model, developed a process for the direct extraction of the ground topography. In this paper, the authors present a generalization of this technique allowing to

C. Lopez-Martinez; A. Alonso; X. Fabregas; K. P. Papathannassiou

2011-01-01

416

Von den Weltkriegen nach Rom: Ideen und Stationen auf dem Weg zur EWG  

Microsoft Academic Search

\\u000a Seit den 1860er Jahren sorgte eine wachsende wirtschaftliche Verflechtung Europas für ein Fortschreiten der faktischen Integration.\\u000a Einer der wichtigsten Theoretiker dieser Integration um einen franzö-sisch-britischen-deutschen Kern war der englische Philosoph\\u000a Herbert Spencer (1820–1903; A System of Synthetic Philosophy, 1855–1896). Diese faktische Integration wurde von verschiedenen sozialen Gruppen\\u000a mitgetragen, deren Identität aus nationalen, aber ebensosehr aus internationalen und europäischen Elementen zusammengesetzt

Wolfgang Schmale

417

Comparison of mega-flood features of the Channeled Scabland and Martian outflow channels using DEMs  

NASA Astrophysics Data System (ADS)

Although current Martian surfaces are too cold and dry to hold liquid water, fluvial features such as valley networks and outflow channels have been observed on the surfaces. The analyses of the fluvial features on Mars are useful for examining past climatic conditions. Outflow channels are the characteristic large flood features on Mars and similar to some large terrestrial flood features such as those in the Channeled Scabland in east-central Washington, USA. The channeled scabland was formed by the Pleistocene Missoula Flood derived from the margins of the Cordilleran Ice Sheet, Glacial Lake Missoula. Thus the Channeled Scabland is useful for a comparison with Martian flood features and examining the paleoenvironment on Mars. However the effect of the Missoula Flood on the formation of the Channeled Scabland has some unresolved questions. Therefore, in this study we analyze the topography of the Channeled Scabland and the area of Glacial Lake Missoula using the ASTER Global Digital Elevation Model (ASTER GDEM) and The