MapFormer: Boosting Change Detection by Using Pre-change Information

Change detection in remote sensing imagery is essential for a variety of applications such as urban planning, disaster management, and climate research. However, existing methods for identifying semantically changed areas overlook the availability of semantic information in the form of existing maps describing features of the earth's surface. In this paper, we leverage this information for change detection in bi-temporal images. We show that the simple integration of the additional information via concatenation of latent representations suffices to significantly outperform state-of-the-art change detection methods. Motivated by this observation, we propose the new task of Conditional Change Detection, where pre-change semantic information is used as input next to bi-temporal images. To fully exploit the extra information, we propose MapFormer, a novel architecture based on a multi-modal feature fusion module that allows for feature processing conditioned on the available semantic information. We further employ a supervised, cross-modal contrastive loss to guide the learning of visual representations. Our approach outperforms existing change detection methods by an absolute 11.7% and 18.4% in terms of binary change IoU on DynamicEarthNet and HRSCD, respectively. Furthermore, we demonstrate the robustness of our approach to the quality of the pre-change semantic information and the absence pre-change imagery. The code will be made publicly available

Implementation of a Remote Control Workplace to Realize Remote Train Control over 5G-Network in Real-World Testing

Remote diagnosis, control and recovery of malfunctioning automated and unmanned trains is seen as a key enabler for automatic train operation along the Grades of Automation taxonomy. Therefore, a major aim of the 5G-Reallabor project, which is set out to bring technology under research into field-testing setups, is the technical demonstration of remote train control over physical distance via a 5G mobile network connection. This technical demonstration requires the development and implementation of a remote control workplace, equipped with all necessary functionalities to attain remote control of a connected train in real-world employing 5G mobile network technology. Significant available knowledge from the prior development and setup of a remote control simulator, called the Train Operator Workplace, served as a starting point for the current topic under investigation. The key step in the process of implementing the remote control workplace for real-world purposes was the derivation of functional user requirements in terms of information needs and control functionality. In the domain of information needs the presentation of in-train train protection system information (European Train Control System), video footage, vehicle status data and traction/braking data was identified, documented in several functional user requirements and implemented accordingly. In the domain of the required control functionality user control over traction, several braking systems, vehicle functions such as horn, light or door release, video cameras and direction of travel were identified and technically realized. Additional safety-related functional requirements mainly related to network quality, connection or package loss were also identified and implemented. The process of scenario-based user requirement derivation and subsequent implementation into a real-world demonstration case ready to satisfy safetyrequirements for physically operating a train on railway infrastructure is presented. Lessonslearned in the field of automatic train operation are discussed to derive insights and bestpractice for further testing in this promising new field of research

Myelin insulation as a risk factor for axonal degeneration in autoimmune demyelinating disease

Axonal degeneration determines the clinical outcome of multiple sclerosis and is thought to result from exposure of denuded axons to immune-mediated damage. Therefore, myelin is widely considered to be a protective structure for axons in multiple sclerosis. Myelinated axons also depend on oligodendrocytes, which provide metabolic and structural support to the axonal compartment. Given that axonal pathology in multiple sclerosis is already visible at early disease stages, before overt demyelination, we reasoned that autoimmune inflammation may disrupt oligodendroglial support mechanisms and hence primarily affect axons insulated by myelin. Here, we studied axonal pathology as a function of myelination in human multiple sclerosis and mouse models of autoimmune encephalomyelitis with genetically altered myelination. We demonstrate that myelin ensheathment itself becomes detrimental for axonal survival and increases the risk of axons degenerating in an autoimmune environment. This challenges the view of myelin as a solely protective structure and suggests that axonal dependence on oligodendroglial support can become fatal when myelin is under inflammatory attack

Kohärente Spektroskopie an InGaAs Quantenpunkten

Excitons in quantum dots represent a remarkably good two-level system with a large optical dipole transition moment. Although most research currently focuses on enhancing their already outstanding properties as single photon emitters they become also increasingly interesting for experimental fundamental research due to their large dipole transition moment. This thesis presents studies which explore fundamental phenomena in quantum dots using coherent spectrocopy methods. First, we will first examine the optical properties of site-controlled quantum dots which were grown using a buried stressor via resonance fluorescence. Subsequently, we will show results that were obtained using photocurrent spectroscopy to study single quantum dots that are embedded in micropillar resonators. This is followed by a study of the Wigner time delay induced by a single quantum dot and which shows that the maximum delay is larger than its dephasing time T2 which is the theoretical limit for coherently scattered fraction. The next section demonstrates that the response of a resonantly driven two-level system which in our case is represented by an exciton in a seminconductor quantum dot depends significantly on the photon statistics of the exciting light field. Most strikingly, the Mollow triplet which we observe under coherent excitation vanishes under thermal excitation. The second part presents results concerned with the resonantly driven biexciton cascade via two- photon excitation. The coherent interaction between light field and excitons gives rise to a complex five-level system. Here, we show for the first time two-photon Rabi oscillations in the temporal domain. Furthermore, we examine the correlations between the different transitions. The measurements show that we can manipulate the time-ordering of the emitted photons by changing for example the laser power. All these studies share the resonant excitation scheme which allows for a coherent manipulation of the states of the quantum dot and grants access to phenomena typical for resonance fluorescence such as the Mollow triplet and Rabi oscillations. In particular the experiments on photon excitation spectroscopy and the studies on the dressed biexciton cascade show that fundamental effects of quantum optics can be explored in a scalable and application oriented setting using quantum dots.Exzitonen in Halbleiterquantenpunkten stellen außergewöhnlich gute Zweiniveausysteme mit einem großen optischen Übergangsdipolmoment dar. Obgleich ihr Hauptpotential sicherlich in der Funktion als Einzelphotonenquelle zu sehen ist, werden sie insbesondere wegen ihres großen optischen Über- gangdipolmoments auch zunehmend interessant für die experimentelle Grundlagenforschung. Die vorliegende Arbeit präsentiert Studien, die mittels kohärenter Spektroskopiemethoden grundlegende Phänomene in Quantenpunkten erforschen. Im ersten Ergebnisteil werden zunächst die optischen Eigenschaften von vorpositionierten Quanten- punkten untersucht, die mittels vergrabener Stressoren gewachsen wurden. Abgeschlossen wird dieser Teil durch resonante Photostromspektroskopie an Quantenpunkten, die in elektrisch kontaktierten Mikrosäulenresonatoren eingebettet sind. Der zweite Teil beginnt mit der Untersuchung der durch einen einzelnen Quantenpunkt induzierten Wigner- Zeitverzögerung, und wir zeigen, dass diese länger ist als seine Dekohärenzzeit T2, welche das theoretische Limit für den kohärent gestreuten Anteil darstellt. Anschließend zeigen wir, dass die Photonenstatistik des anregenden Lichtfelds maßgeblich die Antwort eines resonant getriebenen Zweiniveausystems, in unserem Fall ein Exziton in einem Halbleiterquantenpunkt, bestimmt. Augenfällig ist ist hierbei zum Beispiel, dass das Mollow-Triplett, welches wir unter kohärenter Anregung beobachten, unter thermischer Anregung verschwindet. Der dritte Teil widmet sich dann der Erforschung der resonant getriebenen Biexzitonenkaskade mittels Zweiphotonenanregung. Durch die kohärente Wechselwirkung zwischen Lichtfeld und Exzitonen ergibt sich ein komplexes Fünfniveausystem. Erstmals zeigen wir hier optische Zweiphotonen- Rabioszillationen in der Zeitdomäne. Darüber hinaus untersuchen wir die Korrelationen zwischen den unterschiedlichen Übergängen und zeigen, dass man die Zeitordnung der emittierten Photonen zum Beispiel durch die Leistung des eingestrahlten Lasers manipulieren kann. All diesen Untersuchungen gemeinsam ist die resonante Anregung, die eine kohärente Manipulation der Quantenpunktzustände ermöglicht und somit typische Phänomene der Resonanzfluoreszenz wie Rabioszillationen und das Mollow-Triplett zugänglich macht. Des Weiteren stellen namentlich die Untersuchungen zur Photonenstatistikanregungsspektroskopie und die Versuche an der bekleideten Biexzitonenkaskade unter Beweis, dass grundlegende Effekte der Quantenoptik mit Hilfe von Quantenpunkten in einem skalierbaren und anwendungsnahen Umfeld erforscht werden können

Coherent Spectroscopy of InGaAs Quantum Dots

Excitons in quantum dots represent a remarkably good two-level system with a large optical dipole transition moment. Although most research currently focuses on enhancing their already outstanding properties as single photon emitters they become also increasingly interesting for experimental fundamental research due to their large dipole transition moment. This thesis presents studies which explore fundamental phenomena in quantum dots using coherent spectrocopy methods. First, we will first examine the optical properties of site-controlled quantum dots which were grown using a buried stressor via resonance fluorescence. Subsequently, we will show results that were obtained using photocurrent spectroscopy to study single quantum dots that are embedded in micropillar resonators. This is followed by a study of the Wigner time delay induced by a single quantum dot and which shows that the maximum delay is larger than its dephasing time T2 which is the theoretical limit for coherently scattered fraction. The next section demonstrates that the response of a resonantly driven two-level system which in our case is represented by an exciton in a seminconductor quantum dot depends significantly on the photon statistics of the exciting light field. Most strikingly, the Mollow triplet which we observe under coherent excitation vanishes under thermal excitation. The second part presents results concerned with the resonantly driven biexciton cascade via two- photon excitation. The coherent interaction between light field and excitons gives rise to a complex five-level system. Here, we show for the first time two-photon Rabi oscillations in the temporal domain. Furthermore, we examine the correlations between the different transitions. The measurements show that we can manipulate the time-ordering of the emitted photons by changing for example the laser power. All these studies share the resonant excitation scheme which allows for a coherent manipulation of the states of the quantum dot and grants access to phenomena typical for resonance fluorescence such as the Mollow triplet and Rabi oscillations. In particular the experiments on photon excitation spectroscopy and the studies on the dressed biexciton cascade show that fundamental effects of quantum optics can be explored in a scalable and application oriented setting using quantum dots

Triptychon: Usability evaluation and implementation of a web-based application for patients’ lab and vital parameters

Background A major challenge in healthcare is the interpretation of the constantly increasing amount of clinical data of interest to inpatients for diagnosis and therapy. It is vital to accurately structure and represent data from different sources to help clinicians make informed decisions. Objective We evaluated the usability of our tool ‘Triptychon’ – a three-part visualisation dashboard of essential patients’ medical data provided by a direct overview of their hospitalisation information, laboratory, and vital parameters over time. Methods The study followed a cohort of 20 participants using the mixed-methods approach, including interviews and the usability questionnaires, Health Information Technology Usability Evaluation Scale (Health-ITUES), and User Experience Questionnaire (UEQ). The participant's interactions with the dashboard were also observed. A thematic analysis approach was applied to analyse qualitative data and the quantitative data's task completion time and success rates. Results The usability evaluation of the visualisation dashboard revealed issues relating to the terminology used in the user interface and colour coding in its left and middle panels. The Health-ITUES score was 3.72 (standard deviation (SD) = 1.0), and the UEQ score was 1.6 (SD = 0.74). The study demonstrated improvements in intuitive dashboard use and overall satisfaction with using the dashboard daily. Conclusion The Triptychon dashboard is a promising new tool for medical data presentation. We identified design and layout issues of the dashboard for improving its usability in routine clinical practice. According to users’ feedback, the three panels on the dashboard provided a holistic view of a patient's hospital stay

Spider silk enhanced tissue engineering of cartilage tissue: Approach of a novel bioreactor model using adipose derived stromal cells

Human cartilage tissue remains a challenge for the development of therapeutic options due to its poor vascularization and reduced regenerative capacities. There are a variety of research approaches dealing with cartilage tissue engineering. In addition to different biomaterials, numerous cell populations have been investigated in bioreactor-supported experimental setups to improve cartilage tissue engineering. The concept of the present study was to investigate spider silk cocoons as scaffold seeded with adipose-derived stromal cells (ASC) in a custom-made bioreactor model using cyclic axial compression to engineer cartilage-like tissue. For chemical induction of differentiation, BMP-7 and TGF-β2 were added and changes in cell morphology and de-novo tissue formation were investigated using histological staining to verify chondrogenic differentiation. By seeding spider silk cocoons with ASC, a high colonization density and cell proliferation could be achieved. Mechanical induction of differentiation using a newly established bioreactor model led to a more roundish cell phenotype and new extracellular matrix formation, indicating a chondrogenic differentiation. The addition of BMP-7 and TGF-β2 enhanced the expression of cartilage specific markers in immunohistochemical staining. Overall, the present study can be seen as pilot study and valuable complementation to the published literature