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Bound states in the continuum and Fano resonances in subwavelength resonator arrays
(2021)SAM Research ReportWhen wave scattering systems are subject to certain symmetries, resonant states may decouple from the far-field continuum; they remain localized to the structure and cannot be excited by incident waves from the far field. In this work, we use layer-potential techniques to prove the existence of such states, known as bound states in the continuum, in systems of subwavelength resonators. When the symmetry is slightly broken, this resonant ...Report -
Rigid Sets and Coherent Sets in Realistic Ocean Flows
(2021)SAM Research ReportThis paper focuses on the extractions of Lagrangian Coherent Sets from realistic velocity fields obtained from ocean data and simulations, each of which can be highly resolved and non volume-preserving. Two classes of methods have emerged for such purpose: those relying on the flow map diffeomorphism associated with the velocity field, and those based on spectral decompositions of the Koopman or Perron-Frobenius operators. The two classes ...Report -
Glaciers
(2020)Meltwater from Alpine glaciers is a key component of the Swiss hydrological budget: It significantly contributes to total discharge, sustains minimum flow levels during dry periods, and shapes seasonal regimes. Due to climate change, Swiss glaciers are anticipated to lose between 59% and 93% of their 2018 ice volume by 2100. The associated glacier retreat will impact hydrology, ecosystems, sediment transport, water quality, landscapes, ...Report -
On generalization error estimates of physics informed neural networks for approximating dispersive PDEs
(2021)SAM Research ReportPhysics informed neural networks (PINNs) have recently been widely used for robust and accurate approximation of PDEs. We provide rigorous upper bounds on the generalization error of PINNs approximating solutions of the forward problem for several dispersive PDEs.Report -
Job Situation of ETH Alumni
(2020)KOF StudiesHow do ETH alumni fare in the world of work? How satisfied are they with their job and how much do they earn? Do they think that they perform interesting tasks? How many are in a leadership position? And are there differences between female and male graduates? This report answers these and related questions by summarizing the key findings of an incentivized online survey among ETH alumni that we fielded between November 2019 and ...Report -
Die Schweizer Stellensuchenden im Covid19-Lockdown
(2020)Der Bundesrat hat am 13. März einen partiellen Lockdown der Schweiz beschlossen, der trotz Unterstützungsmassnahmen zu einem starken Anstieg der Arbeitslosigkeit und einem Einbruch bei der Zahl offener Stellen geführt hat. Zwischen dem 21. April und dem 10. Mai haben wir 845 Stellensuchende in der Schweiz zu ihrer persönlichen Situation befragt. Die befragten gaben an, deutlich weniger passende Stelleninserate zu finden als Anfang ...Report -
Proning TACO
(2020)Hospitals treating CovidHospitals Covid1919 patients around the world are using the prone-positioning of patients with Acute Respiratory Distress Syndrome (ARDS) as an effective therapy to increase blood oxygenation and reduce mortality. Turning anaesthetized patients safely requires at least 33--55medical nurses and can be medical tedious to do with current methods. This project proposes a simple mechanical solution to facilitate the ...Report -
The Identity of Oxo-Degradable Plastics and their Use in Switzerland
(2020)Oxo-degradable plastics (ODP) are plastics containing pro-oxidant additives that allegedly promote fragmentation and subsequent biodegradation. However, in practice, ODP do not fully biodegrade under environmental or industrial composting conditions, and thus may serve as a source of microplastics in the environment. In addition, ODP can negatively impact recycling processes. In this study, we investigate the occurrence of ODP in Switzerland ...Report -
Overcoming the curse of dimensionality in the numerical approximation of high-dimensional semilinear elliptic partial differential equations
(2020)SAM Research ReportRecently, so-called full-history recursive multilevel Picard (MLP) approximation schemes have been introduced and shown to overcome the curse of dimensionality in the numerical approximation of semilinear parabolic partial differential equations (PDEs) with Lipschitz nonlinearities. The key contribution of this article is to introduce and analyze a new variant of MLP approximation schemes for certain semilinear elliptic PDEs with Lipschitz ...Report