Suchergebnisse

This paper presents a spatially and temporally adaptive boundary condition to specify the volumetric flow rate for lattice Boltzmann methods. The approach differs from standard velocity boundary conditions because it allows the velocity to vary over the boundary region provided that the total flux through the boundary satisfies a prescribed constraint, which is a typical scenario for laboratory experimental studies. This condition allows the boundary pressure to adjust dynamically to yield a specified boundary flow rate as a means to avoid unphysical mismatch between the boundary velocity and the interior flow field that can arise when a standard velocity boundary condition is applied. The method is validated for simulation of one- and two-fluid flow in complex materials, with conditions determined to match typical experiments used to study flow in porous media. ; This work was supported by Army Research Office grant W911NF-14-1-02877 and National Science Foundation grant 1619767. An award of computer time was provided by the Department of Energy INCITE program. This research also used resources of the Oak Ridge Leadership Computing Facility, which is a DOE Office of Science User Facility supported under Contract DEAC05-00OR22725. Z.L. acknowledges the Australian Government Research Training Program (RTP) Scholarship and the Robert and Helen Crompton travel fund. A.P.S. acknowledges the support of an Australian Research Council Future Fellowship through project FT100100470. This research also used resources and services from the National Computational Infrastructure (NCI), which is supported by the Australian Government.

"In vielen Ländern ist populäre Musik mittlerweile zu einem fixen Bestandteil von Institutionen des kulturellen Erbes wie Archiven oder Museen geworden. Dieser Artikel geht der Frage nach, wie die digitalen, multimedialen Archive Österreichische Mediathek (OeM), Skug Research-Archiv österreichischer Popularmusik (SRA), das Rockarchiv Steiermark und die Trash Rock Archives ein österreichisches bzw. steirisches Pop-Rock-Erbe konstruieren. Ziel des Artikels ist es, die unterschiedlichen Strategien der (An-) Sammlung von Produkten und Dokumenten österreichischen Pop-Rocks sowie die Strategien der Inszenierung dieser Materialien als wertvolle Vergangenheit zu beleuchten. Die Analyse zeigt, dass die untersuchten Archive kein einheitliches Erbe, sondern miteinander konkurrierende Entwürfe eines nationalen bzw. regionalen Pop-Rock-Erbes konstruieren." (Autorenreferat)

Abstract
Numerical solutions to partial differential equations (PDEs) are instrumental for material structural design where extensive data screening is needed. However, traditional numerical methods demand significant computational resources, highlighting the need for innovative optimization algorithms to streamline design exploration. Direct gradient-based optimization algorithms, while effective, rely on design initialization and require complex, problem-specific sensitivity derivations. The advent of machine learning offers a promising alternative to handling large parameter spaces. To further mitigate data dependency, researchers have developed physics-informed neural networks (PINNs) to learn directly from PDEs. However, the intrinsic continuity requirement of PINNs restricts their application in structural mechanics problems, especially for composite materials. Our work addresses this discontinuity issue by substituting the PDE residual with a weak formulation in the physics-informed training process. The proposed approach is exemplified in modeling digital materials, which are mathematical representations of complex composites that possess extreme structural discontinuity. This article also introduces an interactive process that integrates physics-informed loss with design objectives, eliminating the need for pretrained surrogate models or analytical sensitivity derivations. The results demonstrate that our approach can preserve the physical accuracy in data-free material surrogate modeling but also accelerates the direct optimization process without model pretraining.

This book begins with an examination of the numbers of women in physics in English-speaking countries, moving on to examine factors that affect girls and their decision to continue in science, right through to education and on into the problems that women in physics careers face. Looking at all of these topics with one eye on the progress that the field has made in the past few years, and another on those things that we have yet to address, the book surveys the most current research as it tries to identify strategies and topics that have significant impact on issues that women have in the field

Feeling is the existential experience of being matter from the inside. Feeling entangles us with the whole, parallel to the entanglement between observer and observed described in modern physics. Understanding organisms as embodied feeling is the missing link to making sense of the weirdness of modern physics, particularly the fact that the 'observer' is always connected to the 'objects' described (so-called 'entanglement'). In organisms, such entanglement is created through subjective experience—feeling. Feeling is entanglement experienced as inwardness, and as desire for more entanglement in order to unfold and live (Spinoza's 'Conatus'). Through inner experience organisms reveal that 'observations' are not made by 'observers' about 'objects', but actually are the inward aspect of the world's involvement with itself. Every standpoint is an experience of the whole getting in touch with itself. This panpsychic view can help us understand the degree to which all of reality is profused with subjectivity, and how our own subjective experience is an experience which the whole makes about being itself. With this, we are able to formulate a 'general theory of conativity'. This views the desire for mutual transformation and its accompanying creation of standpoints of meaning and concern as an irreducible feature of reality.

'Many of us have stood above a colony of ants and been astounded at their ability to act and organise as a social system. Humans are, of course, smarter, independent free-thinking individuals. Read this book and think again. With eyesight sharpened by math, modeling, and the familiarity with a new landscape he has in part created, Sandy Pentland and his team are mapping out a new world, crawling with information, that offers some real understanding of who we are and who we could be. Welcome to the age of social physics.'