227 research outputs found

    MapFormer: Boosting Change Detection by Using Pre-change Information

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    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

    Erstellung des Feinkonzeptes der Datentechnik für einen meteorologischen Messmasten mit hoher Verfügbarkeit und Analyse der Fehlertoleranzen der dazugehörigen Systeme

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    Im Rahmen dieser Arbeit wird für das Projekt DFWind ein Feinkonzept der Datentechnik für einen meteorologischen Messmasten mit dem Ziel einer hohen Verfügbarkeit vorgestellt. Dabei wird das Projekt kurz illustriert und eine Zusammensetzung sowie Eingrenzung der notwendigen Datentechnik für einen Betrieb von mehreren Sensoren auf dem Messmasten erarbeitet. Um das Thema der Fehlertoleranz zu vermitteln und das Verständnis gegenüber der Auswahl des Feinkonzeptes entgegenzubringen, wird zunächst eine Einführung in dieses Fachgebiet gegeben. Hierbei wird die Terminologie sowie die verschiedenen Arten der Analysemethoden wie eine FMEA und Fehlerbaumanalyse erläutert. Mittels dieser Methoden und sehr vielseitigen Literaturquellen wird jedes einzelne Gerät auf seine Fehlerarten, deren Quellen sowie Vermeidung untersucht. Diese Aspekte werden für eine weitere Eingrenzung der Geräteauswahl und für eine Überprüfung der Integrität des aktuell vorliegenden Konzeptes verwendet. Da die Bewertung der einzelnen Geräte keine Fehler aufgrund der Kombination aller Geräte in einem Verbund identifiziert, wird zusätzlich eine Betrachtung unter weiteren Blickwinkeln durchgeführt. Hierzu zählen menschliche und technische Fehler sowie Ursachen, welche auf die Umwelt zurückzuführen sind

    Hermeneutics of Critical Cyber Security Studies? Rethinking contemporary theoretical debates and the case of Serbia

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    Looking at South-East Europe, and the case of Serbia, offers key insights into reassessing current theoretical debates on cyber (in)security, online disinformation and fake news, and the role of key powers such as China, Russia and the US in this context. Considering the ongoing debate between actor-centered theories of e.g. Balzaq and Cavelty, on the one hand, and political ontology by e.g. Liebetrau and Christensen on the other, the issue of adaptivity of theoretical frameworks in specific cases arises. Hermeneutics represents a possible approach to not only create a synthesis, but also to better understand the relationship between cybersecurity and international relations. In this paper I argue that the specific interrelationship between complexity and interconnectivity of both domestic and foreign factors renders the case of Serbia particularly well suited to investigating our conceptual and empirical understanding of International Relations

    Investigating (sequential) unit asking: an unsuccessful quest for scope sensitivity in willingness to donate judgments

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    People exhibit scope insensitivity: Their expressed valuation of a problem is not proportionate with its scope or size. To address scope insensitivity in charitable giving, Hsee et al. (2013) developed the (Classical) Unit Asking technique, where people are first asked how much they are willing to donate to support a single individual, followed by how much they are willing to donate to support a group of individuals. In this paper, we explored the mechanisms, extensions, and limitations of the technique. In particular, we investigated an extension of the technique, which we call Sequential Unit Asking (SUA). SUA asks people a series of willingness-to-donate questions, in which the number of individuals to be helped increases in a stepwise manner until it reaches the total group size. Across four studies investigating donation judgments (total (Formula presented.)), we did not find evidence that willingness to donate (WTD) judgments to the total group increased with larger groups. Instead, our results suggest that Unit Asking (sequential or classical) increases donation amounts only through a single one-off boost. Further, we find evidence in three out of four studies that the SUA extension increases WTD judgments over Classical Unit Asking. In a fifth study ((Formula presented.)) using a contingent valuation design (instead of donation judgments), we find scope sensitivity using all asking techniques. We conclude that, while it is difficult to create scope sensitivity in WTD judgments, SUA should be considered a promising approach to increase charitable donations

    Influence of Oxygen Partial Pressure during Processing on the Thermoelectric Properties of Aerosol-Deposited CuFeO2

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    In the field of thermoelectric energy conversion, oxide materials show promising potential due to their good stability in oxidizing environments. Hence, the influence of oxygen partial pressure during synthesis on the thermoelectric properties of Cu-Delafossites at high temperatures was investigated in this study. For these purposes, CuFeO2 powders were synthetized using a conventional mixed-oxide technique. X-ray diffraction (XRD) studies were conducted to determine the crystal structures of the delafossites associated with the oxygen content during the synthesis. Out of these powders, films with a thickness of about 25 µm were prepared by the relatively new aerosol-deposition (AD) coating technique. It is based on a room temperature impact consolidation process (RTIC) to deposit dense solid films of ceramic materials on various substrates without using a high-temperature step during the coating process. On these dense CuFeO2 films deposited on alumina substrates with electrode structures, the Seebeck coefficient and the electrical conductivity were measured as a function of temperature and oxygen partial pressure. We compared the thermoelectric properties of both standard processed and aerosol deposited CuFeO2 up to 900 °C and investigated the influence of oxygen partial pressure on the electrical conductivity, on the Seebeck coefficient and on the high temperature stability of CuFeO2. These studies may not only help to improve the thermoelectric material in the high-temperature case, but may also serve as an initial basis to establish a defect chemical model

    Balloon dilatation and stenting for aortic coarctation: a systematic review and meta-analysis

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    Background—There is no systematic assessment of available evidence on effectiveness and comparative effectiveness of balloon dilatation and stenting for aortic coarctation. Methods and Results—We systematically searched 4 online databases to identify and select relevant studies of balloon dilatation and stenting for aortic coarctation based on a priori criteria (PROSPERO 2014:CRD42014014418). We quantitatively synthesized results for each intervention from single-arm studies and obtained pooled estimates for relative effectiveness from pairwise and network meta-analysis of comparative studies. Our primary analysis included 15 stenting (423 participants) and 12 balloon dilatation studies (361 participants), including patients ≥10 years of age. Post-treatment blood pressure gradient reduction to ≤20 and ≤10 mm Hg was achieved in 89.5% (95% confidence interval, 83.7–95.3) and 66.5% (44.1–88.9%) of patients undergoing balloon dilatation, and in 99.5% (97.5–100.0%) and 93.8% (88.5–99.1%) of patients undergoing stenting, respectively. Odds of achieving ≤20 mm Hg were lower with balloon dilatation as compared with stenting (odds ratio, 0.105 [0.010–0.886]). Thirty-day survival rates were comparable. Numerically more patients undergoing balloon dilatation experienced severe complications during admission (6.4% [2.6–10.2%]) compared with stenting (2.6% [0.5–4.7%]). This was supported by meta-analysis of head-to-head studies (odds ratio, 9.617 [2.654–34.845]) and network meta-analysis (odds ratio, 16.23, 95% credible interval: 4.27–62.77) in a secondary analysis in patients ≥1 month of age, including 57 stenting (3397 participants) and 62 balloon dilatation studies (4331 participants). Conclusions—Despite the limitations of the evidence base consisting predominantly of single-arm studies, our review indicates that stenting achieves superior immediate relief of a relevant pressure gradient compared with balloon dilatation

    A Reinforcement Learning Environment for Directed Quantum Circuit Synthesis

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    With recent advancements in quantum computing technology, optimizing quantum circuits and ensuring reliable quantum state preparation have become increasingly vital. Traditional methods often demand extensive expertise and manual calculations, posing challenges as quantum circuits grow in qubit- and gate-count. Therefore, harnessing machine learning techniques to handle the growing variety of gate-to-qubit combinations is a promising approach. In this work, we introduce a comprehensive reinforcement learning environment for quantum circuit synthesis, where circuits are constructed utilizing gates from the the Clifford+T gate set to prepare specific target states. Our experiments focus on exploring the relationship between the depth of synthesized quantum circuits and the circuit depths used for target initialization, as well as qubit count. We organize the environment configurations into multiple evaluation levels and include a range of well-known quantum states for benchmarking purposes. We also lay baselines for evaluating the environment using Proximal Policy Optimization. By applying the trained agents to benchmark tests, we demonstrated their ability to reliably design minimal quantum circuits for a selection of 2-qubit Bell states

    CARD8:A Gas-Exchange-Area-Adjustable Oxygenator for Extremely Preterm Infants

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    Purpose: Worldwide, 600,000 infants are born extremely premature (EP) each year. Supporting the immature lungs of these smallest patients today using mechanical ventilation can cause severe lung damage. Extracorporeal gas exchange (ECMO) used as an “artificial placenta” is expected to provide an alternative treatment to allow full maturation of the lungs. The long-term application for patients doubling their weight every six weeks, requires a new type of “growing” oxygenator.Materials & Methods: We developed a gas-exchange-area-adjustable oxygenator that allows to operate at two different size stages without changing the device nor increasing the flow resistance. Our prototype houses two concentric oxygenator-chambers of equal gas exchange area. When the outer chamber is in operation, the oxygenator provides the required gas exchange area for a 24-week infant. Single-chamber operation allows adaequate gas exchange of volume flows from 50 - 125 ml/min while double-chamber operation then covers flow-demands from 125 - 200 ml/min. Both operational modes in combination can cover the needs of infants from 24 to 28 weeks postmenstrual age. We performed gas-transfer measurements of the prototype in accordance with ISO 7199 and FDA guideline.Results: Gas transport performance for the outer cylinder operating at Vblood = 50 mL/min (24 week premature infant) is VO2 = 1.8 mL/min (= 36 mLO2/Lblood flow). At a flow of Vblood = 125 mL/min the second chamber was switched on and the gas transfer performance increased by 50.1 %. Both chambers have a gas transport performance of VO2 = 4.19 ml/min at Vblood = 150 ml/min (= 28 mLO2/Lblood flow)Conclusion: It could be demonstrated that the gas-transfer of the newly proposed volume-adjustable oxygenator design is sufficient to increase the gas transfer performance while increasing the blood volume flow. We consider this a first milestone for oxygenation of growing EP infants without the need to replace the extracorporeal circuit, avoiding the associated risks

    Leitungsgebundene Störungen eines Flugzeugantriebsstrangs unter asymmetrischer Last

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    In der Luftfahrt ist es notwendig, Situationen zu beherrschen, die in einem stationären Betrieb eines Antriebstrangs eine untergeordnete Rolle spielen. Dazu gehört die Betrachtung systematischer Störursachen, aber auch die Betrachtung von Fehlerfällen und deren Auswirkung. Dieser Beitrag erläutert angesichts der absehbaren Elektrifizierung der Luftfahrt, wie das elektromagnetische Störpotenzial eines elektrischen Antriebsstrangs entsteht und inwiefern es durch existierende Luftfahrtstandards [1] abgesichert ist. Er benennt die systematische Ursache von Störspannungen und die Auswirkung von Netzformen und Asymmetrien der Last. Die Auswahl der Umrichtertopologie, die Wahl der Netzform, und im mehrphasigen Antriebsstrang die Betrachtung von Asymmetrien und damit auch seltene Fehlerfällen, die elektrisch tolerierbar sein können, beeinflussen das Maß der zu beherrschenden Störwirkung. Das Störpotenzial ist eine Folge von Architekturentscheidungen, die früh im Entwicklungsprozess getroffen werden sollten

    Glutamic Acid Residues in HIV-1 p6 Regulate Virus Budding and Membrane Association of Gag

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    The HIV-1 Gag p6 protein regulates the final abscission step of nascent virions from the cell membrane by the action of its two late (l-) domains, which recruit Tsg101 and ALIX, components of the ESCRT system. Even though p6 consists of only 52 amino acids, it is encoded by one of the most polymorphic regions of the HIV-1 gag gene and undergoes various posttranslational modifications including sumoylation, ubiquitination, and phosphorylation. In addition, it mediates the incorporation of the HIV-1 accessory protein Vpr into budding virions. Despite its small size, p6 exhibits an unusually high charge density. In this study, we show that mutation of the conserved glutamic acids within p6 increases the membrane association of Pr55 Gag followed by enhanced polyubiquitination and MHC-I antigen presentation of Gag-derived epitopes, possibly due to prolonged exposure to membrane bound E3 ligases. The replication capacity of the total glutamic acid mutant E0A was almost completely impaired, which was accompanied by defective virus release that could not be rescued by ALIX overexpression. Altogether, our data indicate that the glutamic acids within p6 contribute to the late steps of viral replication and may contribute to the interaction of Gag with the plasma membrane
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