238 research outputs found

    Spillback Changes the Long-Term Behavior of Dynamic Equilibria in Fluid Queuing Networks

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    We study the long-term behavior of dynamic traffic equilibria and find that it heavily depends on whether spillback is captured in the traffic model or not. We give an example where no steady state is reached. Although the example consists of a single-commodity instance with constant inflow rate, the Nash flow over time consists of infinitely many phases. This is in contrast to what has been proven for Nash flows over time without spillback [Cominetti et al., 2021; N. Olver et al., 2021]. Additionally, we show that similar phase oscillations as in the Nash flow over time with spillback can be observed in the co-evolutionary transport simulation MATSim. This reaffirms the robustness of the findings as the simulation does (in contrast to Nash flows over time) not lead to exact user equilibra and, moreover, models discrete time steps and vehicles

    Confirmation of an He I evaporating atmosphere around the 650-Myr-old sub-Neptune HD235088 b (TOI-1430 b) with CARMENES

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    HD235088 (TOI-1430) is a young star known to host a sub-Neptune-sized planet candidate. We validated the planetary nature of HD235088 b with multiband photometry, refined its planetary parameters, and obtained a new age estimate of the host star, placing it at 600-800 Myr. Previous spectroscopic observations of a single transit detected an excess absorption of He I coincident in time with the planet candidate transit. Here, we confirm the presence of He I in the atmosphere of HD235088 b with one transit observed with CARMENES. We also detected hints of variability in the strength of the helium signal, with an absorption of -0.91±\pm0.11%, which is slightly deeper (2σ\sigma) than the previous measurement. Furthermore, we simulated the He I signal with a spherically symmetric 1D hydrodynamic model, finding that the upper atmosphere of HD235088 b escapes hydrodynamically with a significant mass loss rate of (1.5-5) ×\times1010^{10}g s1^{-1}, in a relatively cold outflow, with TT=3125±\pm375 K, in the photon-limited escape regime. HD235088 b (RpR_{p} = 2.045±\pm0.075 R_{\oplus}) is the smallest planet found to date with a solid atmospheric detection - not just of He I but any other atom or molecule. This positions it a benchmark planet for further analyses of evolving young sub-Neptune atmospheres.Comment: Accepted for publication in A&A. 17 pages, 18 figure

    Embodied Conceivability: How to Keep the Phenomenal Concept Strategy Grounded

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    The Phenomenal Concept Strategy offers the physicalist perhaps the most promising means of explaining why the connection between mental facts and physical facts appears to be contingent even though it is not. In this article, we show that the large body of evidence suggesting that our concepts are often embodied and grounded in sensorimotor systems speaks against standard forms of the PCS. We argue, nevertheless, that it is possible to formulate a novel version of the PCS that is thoroughly in keeping with embodied cognition, focuses on features of physical concepts, and succeeds in explaining the appearance of contingency

    Three (Potential) Pillars of Transnational Economic Justice: The Bretton Woods Institutions as Guarantors of Global Equal Treatment and Market Completion

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    This essay aims to bring two important lines of inquiry and criticism together. It first lays out an institutionally enriched account of what a just world economic order will look like. That account prescribes, via the requisites to that mechanism which most directly instantiate the account, three realms of equal treatment and market completion - the global products, services, and labor markets; the global investment/financial markets; and the global preparticipation opportunity allocation. The essay then suggests how, with minimal if any departure from familiar canons of traditional international legal mandate interpretation, each of the Bretton Woods institutions - particularly the GATT/WTO and the IMF - can be viewed at least in part as charged with the task of fostering equal treatment and ultimate market completion within one of those three realms. The piece then argues that one of the institutions in particular - the World Bank - has, for reasons of at best negligent and at worst willful injustice on the part of influential state actors in the world community, fallen farthest short in pursuit of what should be viewed as its proper mandate. The article accordingly concludes that a fuller empowerment of the Bank to effect its ideal mission will press the Bretton Woods system more nearly into ethical balance, and with it the world into justice; and that full empowerment of the GATT/WTO and IMF should be partly conditioned upon the fuller empowerment of the Bank
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