Widom's formula for discontinuous matrix-valued symbols

We prove Widom's formula for the asymptotic behaviour of truncated Wiener-Hopf operators with discontinuous matrix-valued symbols for three different classes of test functions. The symbols may depend on both position and momentum except when closing the asymptotics for twice differentiable test functions with H\"older singularities. The cut-off domains are allowed to have piece-wise differentiable boundaries. The results can be applied to establish a logarithmically enhanced area law for the entanglement entropy of a non-interacting gas of free Dirac fermions under suitable conditions on the mass and the Fermi energy.Comment: 38 page

Establishing Trustworthiness: Rethinking Tasks and Model Evaluation

Language understanding is a multi-faceted cognitive capability, which the Natural Language Processing (NLP) community has striven to model computationally for decades. Traditionally, facets of linguistic intelligence have been compartmentalized into tasks with specialized model architectures and corresponding evaluation protocols. With the advent of large language models (LLMs) the community has witnessed a dramatic shift towards general purpose, task-agnostic approaches powered by generative models. As a consequence, the traditional compartmentalized notion of language tasks is breaking down, followed by an increasing challenge for evaluation and analysis. At the same time, LLMs are being deployed in more real-world scenarios, including previously unforeseen zero-shot setups, increasing the need for trustworthy and reliable systems. Therefore, we argue that it is time to rethink what constitutes tasks and model evaluation in NLP, and pursue a more holistic view on language, placing trustworthiness at the center. Towards this goal, we review existing compartmentalized approaches for understanding the origins of a model's functional capacity, and provide recommendations for more multi-faceted evaluation protocols.Comment: Accepted at EMNLP 2023 (Main Conference), camera-read

Economic and Environmental Aspects of Aircraft Recycling

Aircraft recycling can be considered as an important step on the path to sustainable aviation, as valuable resources used in aircraft construction can be returned for use in a circular economy by these activities. Our results have shown that the market for aircraft recycling is emerging with great future relevance due to the increasing number of aircraft retirements expected in the future. The costs of recycling per aircraft vary by aircraft class and number of engines. The costs range from USD 109,000 for a twin-engine regional jet to USD 268,000 for a four-engine widebody jet. The costs for a twin-engine narrowbody jet lie in between at USD 138,000. In this paper, we investigated the economic efficiency of aircraft recycling expressed as the ratio of average dismantling and recycling costs per aircraft and engine in USD compared with the achieved environmental benefit in average tons recycled material or re-used parts. This ratio revealed that aircraft recycling leads to notable environmental benefits as a large share (60%) of the total structural weight is being re-used at given costs. The average economic efficiency is estimated at 1,666 USD/ton for a widebody aircraft, 3,531 USD/ton for a narrowbody jet and 6,693 USD per ton for a regional jet. In future, aircraft recycling will be facing a number of major challenges as the number of retired aircraft will increase and the share of composite material to be recycled will rise significantly in the medium and long term - for which material no satisfying technological recycling solution exists today. In addition, the environmental pressure from politics and society is expected to be increasing in future. Against this background, we recommend to effectively enforce ambitious recycling standards for retired aircraft on a global level. Furthermore, as recycling technologies for aircraft composite materials are not mature currently, significant R&D investments are needed for these technologies

Kooperative Störungsdiagnose durch Bediener und Assistenzsystem für Verarbeitungsanlagen

Das Betriebsverhalten von Verarbeitungsanlagen ist geprägt von häufig auftretenden Störungen, die von Bedienern manuell beseitigt werden müssen und deren Arbeitsaufgabe dominieren. Technische Systeme zur Bedienerunterstützung sind für diese Anlagen bisher nicht etabliert. Davon ausgehend wird ein Modell für die kooperative Störungsdiagnose durch Bediener und Assistenzsystem vorgestellt. Durch die Kombination von Bedienerwissen und Prozessdaten wird damit eine gemeinsame Zustandsrepräsentation erstellt, die zu einer zielgenauen Fallerkennung führt und so Bediener bei der Fehlerbeseitigung unterstützt. Als Grundlage für die Entwicklung des Assistenzsystems werden erste Untersuchungen zum Einfluss der Präsentationsform von Lösungsvorschlägen auf die Lösungszeit, die Fehlerraten und die Häufigkeit des Heranziehens von Zusatzinformationen präsentiert

Investigation of Colonic Regeneration via Precise Damage Application Using Femtosecond Laser-Based Nanosurgery

Organoids represent the cellular composition of natural tissue. So called colonoids, organoids derived from colon tissue, are a good model for understanding regeneration. However, next to the cellular composition, the surrounding matrix, the cell–cell interactions, and environmental factors have to be considered. This requires new approaches for the manipulation of a colonoid. Of key interest is the precise application of localized damage and the following cellular reaction. We have established multiphoton imaging in combination with femtosecond laser-based cellular nanosurgery in colonoids to ablate single cells in the colonoids’ crypts, the proliferative zones, and the differentiated zones. We observed that half of the colonoids recovered within six hours after manipulation. An invagination of the damaged cell and closing of the structure was observed. In about a third of the cases of targeted crypt damage, it caused a stop in crypt proliferation. In the majority of colonoids ablated in the crypt, the damage led to an increase in Wnt signalling, indicated via a fluorescent lentiviral biosensor. qRT-PCR analysis showed increased expression of various proliferation and Wnt-associated genes in response to damage. Our new model of probing colonoid regeneration paves the way to better understand organoid dynamics on a single cell level. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Longitudinal health-related quality of life assessment in children with congenital heart disease

[Abstract] Objective: Health-related quality of life (HRQoL) has become an important outcome measure for patients with congenital heart disease (CHD). The aim of this study was to evaluate the natural course of HRQoL from longitudinal assessment in children with CHD. Patients and Methods: From July 2014 to February 2020 this longitudinal study recruited 317 children with CHD (113 girls, 35.6%) aged 6 to 18 years (11.6 ± 2.9 years). HRQoL was assessed with the generic, self-reported and age-adapted KINDL® questionnaire. During a mean follow-up period of 2.2 ± 1.3 years, 195 patients had one HRQoL reassessment, 70 two, 40 three and 12 patients four or more re-assessment, respective. Results: Overall HRQoL at baseline was 78.7 ± 9.3. During follow-up there were no changes in HRQoL over time (0.03 [–0.01–0.07]; p = 0.195). In a linear mixed model neither CHD severity, the diagnostic subgroup, age, BMI, surgical history nor gender could be linked to a change in HRQoL during the follow-up time. Only children with higher age baseline (–0.48 [–0.85––0.11]; p = 0.010) had lower HRQoL. Same trend was seen for BMI (–0.19 [–0.41–0.03]; p = 0.099). Conclusion: Older children with CHD have significantly worse HRQoL, but they evolve similarly to younger children over time. Since no demographic or clinical variable could be linked to the course of HRQoL, it seems that individual HRQoL courses are not predictable and routine HRQoL evaluations seem to be necessary for acute decision making in clinical practice

Investigating afforestation and bioenergy CCS as climate change mitigation strategies

The land-use sector can contribute to climate change mitigation not only by reducing greenhouse gas (GHG) emissions, but also by increasing carbon uptake from the atmosphere and thereby creating negative CO2 emissions. In this paper, we investigate two land-based climate change mitigation strategies for carbon removal: (1) afforestation and (2) bioenergy in combination with carbon capture and storage technology (bioenergy CCS). In our approach, a global tax on GHG emissions aimed at ambitious climate change mitigation incentivizes land-based mitigation by penalizing positive and rewarding negative CO2 emissions from the land-use system. We analyze afforestation and bioenergy CCS as standalone and combined mitigation strategies. We find that afforestation is a cost-efficient strategy for carbon removal at relatively low carbon prices, while bioenergy CCS becomes competitive only at higher prices. According to our results, cumulative carbon removal due to afforestation and bioenergy CCS is similar at the end of 21st century (600–700 GtCO2), while land-demand for afforestation is much higher compared to bioenergy CCS. In the combined setting, we identify competition for land, but the impact on the mitigation potential (1000 GtCO2) is partially alleviated by productivity increases in the agricultural sector. Moreover, our results indicate that early-century afforestation presumably will not negatively impact carbon removal due to bioenergy CCS in the second half of the 21st century. A sensitivity analysis shows that land-based mitigation is very sensitive to different levels of GHG taxes. Besides that, the mitigation potential of bioenergy CCS highly depends on the development of future bioenergy yields and the availability of geological carbon storage, while for afforestation projects the length of the crediting period is crucial.Peer Reviewe

Investigating afforestation and bioenergy CCS as climate change mitigation strategies

The land-use sector can contribute to climate change mitigation not only by reducing greenhouse gas (GHG) emissions, but also by increasing carbon uptake from the atmosphere and thereby creating negative CO2 emissions. In this paper, we investigate two land-based climate change mitigation strategies for carbon removal: (1) afforestation and (2) bioenergy in combination with carbon capture and storage technology (bioenergy CCS). In our approach, a global tax on GHG emissions aimed at ambitious climate change mitigation incentivizes land-based mitigation by penalizing positive and rewarding negative CO2 emissions from the land-use system. We analyze afforestation and bioenergy CCS as standalone and combined mitigation strategies. We find that afforestation is a cost-efficient strategy for carbon removal at relatively low carbon prices, while bioenergy CCS becomes competitive only at higher prices. According to our results, cumulative carbon removal due to afforestation and bioenergy CCS is similar at the end of 21st century (600–700 GtCO2), while land-demand for afforestation is much higher compared to bioenergy CCS. In the combined setting, we identify competition for land, but the impact on the mitigation potential (1000 GtCO2) is partially alleviated by productivity increases in the agricultural sector. Moreover, our results indicate that early-century afforestation presumably will not negatively impact carbon removal due to bioenergy CCS in the second half of the 21st century. A sensitivity analysis shows that land-based mitigation is very sensitive to different levels of GHG taxes. Besides that, the mitigation potential of bioenergy CCS highly depends on the development of future bioenergy yields and the availability of geological carbon storage, while for afforestation projects the length of the crediting period is crucial