Application of terrestrial‚ 'structure-from-motion' photogrammetry on a medium-size Arctic valley glacier: potential, accuracy and limitations

Terrestrial photogrammetry was the standard method for mapping high mountain terrain in the early days of mountain cartography, until it was replaced by aerial photogrammetry and airborne laser scanning. Modern lowprice digital single-lens reflex (DSLR) cameras and highly automatic and cheap digital computer vision software with automatic image matching and multiview-stereo routines suggest the rebirth of terrestrial photogrammetry, especially in remote regions, where airborne surveying methods are expensive due to high flight costs. Terrestrial photogrammetry and modern automated image matching is widely used in geodesy, however, its application in glaciology is still rare, especially for surveying ice bodies at the scale of some km2, which is typical for valley glaciers. In August 2013 a terrestrial photogrammetric survey was carried out on Freya Glacier, a 6km2 valley glacier next to Zackenberg Research Station in NE-Greenland, where a detailed glacier mass balance monitoring was initiated during the last IPY. Photos with a consumer grade digital camera (Nikon D7100) were taken from the ridges surrounding the glacier. To create a digital elevation model, the photos were processed with the software photoscan. A set of 100 dGPS surveyed ground control points on the glacier surface was used to georeference and validate the final DEM. Aim of this study was to produce a high resolution and high accuracy DEM of the actual surface topography of the Freya glacier catchment with a novel approach and to explore the potential of modern low-cost terrestrial photogrammetry combined with state-of-the-art automated image matching and multiview-stereo routines for glacier monitoring and to communicate this powerful and cheap method within the environmental research and glacier monitoring community

Zeit ohne Zeugen

Zeitzeugen, Überlebende der Shoah haben in der unmittelbaren Vergangenheit und Gegenwart eine immens wichtige Rolle in Bildungs- und Vermittlungsbemühungen zur Shoah gespielt. In absehbarer Zukunft werden wir jedoch ohne sie auskommen müssen. Diese Arbeit geht von der These aus, dass Strategien für die Zeit nach den Zeugen stark auf videographierten lebensgeschichtlichen Interviews aufbauen werden und, dass die größte Herausforderung sein wird, die Autorität der lebenden Zeugen in der Arbeit mit den Videoaufzeichnungen weitestgehend zu erhalten. Im ersten Teil dieser Arbeit werden zuerst die verschiedenen Bedeutungsebenen von “Zeugen” “Zeugnis” und “Zeugenschaft” theoretisch untersucht, eine als notwendig betrachtete Vorbedingung zum Verständnis der Bedeutung der Zeugenschaften. Im juridischen Kontext wird der Zeuge lediglich als problematische Auskunftsquelle wahrgenommen, dessen Zeugnis von einem stark regelmentierten Interaktionsritual vor Gericht dominiert wird. Ebenso die klassische Historiographie steht dem Augenzeugen kritisch gegenüber, lediglich in der jüngeren Vergangenheit gewinnt die “oral history” an Bedeutung. Philosophische Betrachtungen arbeiten sich weitgehend an der Frage des epistemischen Wahrheitsgehaltes eines Zeugnisses ab. Im zweiten Teil werden die Erkenntnisse aus der Theorie mit den konkreten Zeugenschaften von Überlebenden der Shoah über ihre Erlebnisse konfrontiert. Es ergibt sich, dass die theoretisch erarbeiteten Kategorien und Erklärungen unzureichend sind, den Wert der Zeugenschaften zu begreifen. Die mitunter fehlende faktische Genauigkeit der Erinnerungen ist jedoch ebensowenig entscheidend für den Wert der Zeugnisse, wie die mitunter fehlende umfassende Darstellung bestimmter Ereignisse. Hilfreich an dieser Stelle werden die Konzepte des israelischen Philosophen Avishai Margalit herangezogen, der den Wert der Zeugenschaften zur Shoah in deren “moralischer Autorität” sieht. Das unmittelbare Erleben bzw. Erleiden verleiht den Überlebenden der Shoah die ultimative Autorität. Für diese Autorität ist irrelevant, ob alle Details in der Erzählung korrekt sind. Hier ist es auch notwendig, den Umstand, dass Überlebende der Shoah oft schwer traumatisiert sind, mit in Betracht zu ziehen. Der Überlebende der Shoah kann vielleicht nicht exakt beschreiben, was sich genau zugetragen hat, aber er kann beschreiben wie es sich angefühlt hat und was es bedeutet hat die Shoah zu überleben. Für den dritten Teil der Arbeit wurden drei ExpertInnen aus drei weltweit führenden Forschungs- und Bildungsinstitutionen im Bereich Shoah-Forschung zu der Frage interviewt, wie sie in ihrer konkreten Vermittlungsarbeit mit dem Wegfall der Überlebenden umgehen. Es handelt sich um Amy M. Carnes (Associate Director, International Programs des Shoah Foundation Institute for Visual History and Education an der University of Southern California in Los Angeles, USA), Michael Haley Goldman (Director of the Global Classroom Initiative am United States Holocaust Memorial Museum in Washington DC) sowie Noa Mkayton (Leiterin der deutschsprachigen Abteilung an der International School for Holocaust Studies in Yad Vashem, Jerusalem). In der qualitativen Analyse der Antworten ergibt sich, dass in allen drei Institutionen ein starkes Bewusstsein über den immensen Wert der Zeugnisse der Überlebenden vorherrscht. Die konkreten Ansätze für die Zeit nach den Zeugen bauen überwiegend auf videographierten mehrstündigen lebengeschichtlichen Interviews auf, die in allen drei Institutionen aufgezeichnet wurden. Am weitesten fortgeschritten ist zum Zeitpunkt der Analyse Ende 2011 die Arbeit an der Shoah Foundation in Los Angeles, die mit IWitness bereits ein einsatzfähiges Programm entwickelt haben, das seit Januar 2012 bereits in Schulen verwendet wird.Starting point for this paper was the question, how it would be possible to proceed in holocaust education efforts in the not so distant future, when survivors would not be able be part of this effort any more. As a main thesis, I expect video recorded interviews with survivors to play a mayor role in the ideas for educational programs currently developed for the future. Furthermore I expect it to be crucial to maintain the authority of the survivors’ testimony in its video-graphed form and embedding in any program. In order to answer the questions put forward, it is necessary to understand the special value of survivor’s testimony. Therefore a brief look at the theoretical meaning of “witness” and “testimony” in different contexts was deemed a necessary prerequisite. In the judicial field, the witness is reduced to a source for facts, which in court are supposed to be revealed in a highly formalized ritual. However the testimony of the witness is generally not to be trusted, a notion that is shared with the classical historiographic context of testimony. Recently, with wider acceptance of the methods of “oral history” this is more an more changing. Philosophical approaches to testimony and witnesses are centered on wether or not there was any “epistemical truth” in testimony. Applying the findings to witnesses of the Shoah in specific, quickly it becomes evident, that the theoretical concepts and thoughts on testimony fall short of being able to explain the value of the witnesses of the Shoah. The thoughts of Israeli philosopher Avishai Margalit provide the much needed help here. According to Margalit, it is not important if the testimony of a survivor of the Shoah is 100% accurate in it’s facts, or provides a profound overview of a specific event, something the often traumatized survivors would not be able to provide. The authority of the witness of the Shoah is a moral authority, derived from the personal experience or suffering of the survivor him or herself. A survivor cannot describe what exactly happened, but can describe how it felt, what it meant to be there and live through the Shoah. The third part of the paper is dealing with the main research question: How can we continue once the survivors are not with us any more? In interviews conducted with three experts working for leading institutions in Holocaust education and research, I wanted to find out the strategies of these institutions to deal with the matter. These experts were: Amy M. Carnes (Associate Director, International Programs des Shoah Foundation Institute for Visual History and Education at the University of Southern California in Los Angeles, USA), Michael Haley Goldman (Director of the Global Classroom Initiative at the United States Holocaust Memorial Museum in Washington DC) and Noa Mkayton (Head of the German Desk at the International School for Holocaust Studies in Yad Vashem, Jerusalem). A qualitative analysis of the answers reveals, that all three institutions are fully aware of the special value survivors provided to their educational and outreach programs. All three of them are in different stages of preparations for the day, when they cannot be part of their programs any more. Most of the efforts are indeed based on video recordings of interviews with survivors. The most advanced answer has been developed by the Shoah Foundation in Los Angeles. Their program IWitness launched in a limited pilot phase in February 2012 and is already being used for Holocaust education in schools in the United States

iGraph: Intelligent Enterprise Information Logistics

Engineers in the automotive domain are confronted with a huge load of information making it difficult for them to identify the information relevant for performing their tasks. Particularly challenging is the alignment of process information, such as office files, checklists, and guidelines with business processes. In previous work, we introduced the concept of process-oriented information logistics (POIL) enabling the intelligent delivery of process information along business processes. In this paper, we present iGraph, an application implementing POIL. Specifically, iGraph demonstrates how engineers can be supported with relevant process information during the review of product requirements

A multipurpose laboratory diffractometer for operando powder X-ray diffraction investigations of energy materials

Laboratory X-ray diffractometers are among the most widespread instruments in research laboratories around the world and are commercially available in different configurations and setups from various manufacturers. Advances in detector technology and X-ray sources push the data quality of in-house diffractometers and enable the collection of time-resolved scattering data during operando experiments. Here, the design and installation of a custom-built multipurpose laboratory diffractometer for the crystallographic characterization of battery materials are reported. The instrument is based on a Huber six-circle diffractometer equipped with a molybdenum microfocus rotating anode with 2D collimated parallel-beam X-ray optics and an optional two-bounce crystal monochromator. Scattered X-rays are detected with a hybrid single-photon-counting area detector (PILATUS 300K-W). An overview of the different diffraction setups together with the main features of the beam characteristics is given. Example case studies illustrate the flexibility of the research instrument for time-resolved operando powder X-ray diffraction experiments as well as the possibility to collect higher-resolution data suitable for diffraction line-profile analysis

Crossovers in the Two Dimensional Ising Spin Glass with ferromagnetic next-nearest-neighbor interactions

By means of extensive computer simulations we analyze in detail the two dimensional $\pm J$ Ising spin glass with ferromagnetic next-nearest-neighbor interactions. We found a crossover from ferromagnetic to ``spin glass'' like order both from numerical simulations and analytical arguments. We also present evidences of a second crossover from the ``spin glass'' behavior to a paramagnetic phase for the largest volume studied.Comment: 19 pages with 9 postscript figures also available at http://chimera.roma1.infn.it/index_papers_complex.html. Some changes in captions of figures 1 and

Implementation and performance analysis of bridging Monte Carlo moves for off-lattice single chain polymers in globular states

Bridging algorithms are global Monte Carlo moves which allow for an efficient sampling of single polymer chains. In this manuscript we discuss the adaptation of three bridging algorithms from lattice to continuum models, and give details on the corrections to the acceptance rules which are required to fulfill detailed balance. For the first time we are able to compare the efficiency of the moves by analyzing the occurrence of knots in globular states. For a flexible homopolymer chain of length N=1000, independent configurations can be generated up to two orders of magnitude faster than with slithering snake moves.Comment: 12 pages, 5 figures, preprint submitted to computer physics communication