Semantic Drift in Multilingual Representations

Multilingual representations have mostly been evaluated based on their performance on specific tasks. In this article, we look beyond engineering goals and analyze the relations between languages in computational representations. We introduce a methodology for comparing languages based on their organization of semantic concepts. We propose to conduct an adapted version of representational similarity analysis of a selected set of concepts in computational multilingual representations. Using this analysis method, we can reconstruct a phylogenetic tree that closely resembles those assumed by linguistic experts. These results indicate that multilingual distributional representations that are only trained on monolingual text and bilingual dictionaries preserve relations between languages without the need for any etymological information. In addition, we propose a measure to identify semantic drift between language families. We perform experiments on word-based and sentence-based multilingual models and provide both quantitative results and qualitative examples. Analyses of semantic drift in multilingual representations can serve two purposes: They can indicate unwanted characteristics of the computational models and they provide a quantitative means to study linguistic phenomena across languages.

Computational Representations of Myocardial Infarct Scars and Implications for Arrhythmogenesis

Image-based computational modeling is becoming an increasingly used clinical tool to provide insight into the mechanisms of reentrant arrhythmias. In the context of ischemic heart disease, faithful representation of the electrophysiological properties of the infarct region within models is essential, due to the scars known for arrhythmic properties. Here, we review the different computational representations of the infarcted region, summarizing the experimental measurements upon which they are based. We then focus on the two most common representations of the scar core (complete insulator or electrically passive tissue) and perform simulations of electrical propagation around idealized infarct geometries. Our simulations highlight significant differences in action potential duration and focal effective refractory period (ERP) around the scar, driven by differences in electrotonic loading, depending on the choice of scar representation. Finally, a novel mechanism for arrhythmia induction, following a focal ectopic beat, is demonstrated, which relies on localized gradients in ERP directly caused by the electrotonic sink effects of the neighboring passive scar.

Architecture after Drafting

"In den letzten zwei Jahrzehnten wurde die Dominanz des Zeichnens für die Architektur von einer ganzen Reihe von digitalen Repräsentationstechniken verdrängt. Der Beitrag stellt eine kritische Antwort auf Mario Carpos These dar, dieser Wandel bringe Architektur zu einer »autographischen« Praxis zurück, die noch vor die Renaissance zurückreiche. Demgegenüber argumentiert der Beitrag, dass Architektur nach dem Modell von Rosalind Kraus als post-medium art (»postmediale Kunst«) gedacht werden sollte. </br></br>Over the last two decades drawing has been displaced from its dominant role in architecture by a range of computational representations. This article offers a critical response to Mario Carpo's recent argument that this shift returns architecture to an 〉autographic〈 mode of practice not seen since before the Renaissance. In contrast, I suggest that architecture today should be thought of through Rosalind Krauss's model of a post-medium art. "