A learning based approach for designing extended unit cell metagratings

The possibility of arbitrary spatial control of incident wavefronts with the subwavelength resolution has driven research into dielectric optical metasurfaces in the last decade. The unit-cell based metasurface design approach that relies on a library of single element responses is known to result in reduced efficiency attributed to the inadequate accounting of the coupling effects between meta-atoms. Metasurfaces with extended unit-cells containing multiple resonators can improve design outcomes but their design requires extensive numerical computing and optimizations. We report a deep learning based design methodology for the inverse design of extended unit-cell metagratings. In contrast to previous reports, our approach learns the metagrating spectral response across its reflected and transmitted orders. Through systematic exploration, we discover network architectures and training dataset sampling strategies that allow such learning without requiring extensive ground-truth generation. The one-time investment of model creation can then be used to significantly accelerate numerical optimization of multiple functionalities as demonstrated by considering the inverse design of various spectral and polarization dependent splitters and filters. The proposed methodology is not limited to these proof-of-concept demonstrations and can be broadly applied to meta-atom-based nanophotonic system design and in realising the next generation of metasurface functionalities with improved performance.

The Now and the Relation between Motion and Time in Aristotle: A Systematic Reconstruction

This paper reconstructs Aristotle’s account of the now to clarify the relationship between motion and the number of time. If time is the number of motion, then the priority of motion can be grasped by examining his theory of number. The paper gives a systematic overview of the now in relation to motion, to the constitution of units, and to number in general. This shows that, for Aristotle, the now is not itself an extended unit, and defends his view against claims that time is implicitly prior to motion. The temporal number is co-constituted by the soul and motion, and the now is key to understanding how this occurs. This paper shows that, just as numbers are generated by the soul, time emerges through the soul’s articulation of motion using a now. The now is a limit that marks out and sets up the abstraction of a temporal unit from its underlying motion. This reconstruction provides a strong basis for the claim that time is ontologically dependent on motion, and secondarily on the soul.

Evaluative Meaning in Translation

Evaluative meaning is frequently understood as a form of connotation, pertaining to single lexical items. However, the term has recently been applied also to longer stretches of text, spanning several words. The paper generally deals with the latter aspect and provides a corpus-driven analysis of several Slovene and English phrases that may appear semantically neutral, yet turn out to be heavily non-neutral in terms of their semantic properties. After a short introduction of the main approaches to the topic, including its dilemmas, the paper focuses on the L1-into-L2 translation of such strings, with particular emphasis on proper rendering of the evaluative meaning. While further research is warranted into the matter, the work presented here attests to the complex and ubiquitous nature of the Sinclairian extended unit of meaning.

Cross-linguistic semantic prosody: The case of ‘commit’, ‘signs of’ and ‘utterly’ and their Norwegian correspondences

This paper reports on a contrastive study of semantic prosody in English and Norwegian. Semantic prosody refers to the communicative function of extended units of meaning (Sinclair 1996, Stubbs 2013), i.e. «the semantic prosody of an item is the reason why it is chosen, over and above the semantic preferences that also characterise it» (Sinclair 1998: 20), where an item is equated with the sequence of words constituting an extended unit of meaning. The paper presents three case studies of English units with an established negative prosody containing the core items ‘commit’, ‘signs of’ and ‘utterly’. The Norwegian correspondences of these items are identified on the basis of a bidirectional corpus, viz. the English-Norwegian Parallel Corpus. These correspondences serve as the starting point for an investigation of cross-linguistic prosodies. It is shown that while units with ‘commit’ and ‘signs of’ have good Norwegian matches in terms of semantic prosody, units with ‘utterly’ are less stable across the two languages, underlining the importance of carrying out studies of this kind in order to improve the cross-linguistic understanding of extended units of meaning. This in turn has implications for how teachers, translators and lexicographers choose to present words in isolation or as part of larger, extended units.

Form, meaning and genre in the Scherzo of Mahler’s Second Symphony

This study offers a multilevel analysis of the form of the third movement of Mahler’s Second Symphony providing three frameworks (those of a sophisticated trio form, a bipartite idiosyncratic form, and an imaginary, ‘endless’ form). Conceiving of the formal dimensions of the Scherzo of Mahler’s Second Symphony as ontological models, I will contextualize these with reference to the writings of E.T.A. Hoffmann, Schopenhauer, and Nietzsche. Among the new discoveries of this investigation, I will outline the implications of three hitherto neglected circumstances: first, the movement’s first extended unit itself constitutes a self-contained symphonic scherzo movement; next, the movement can be described as two succeeding permutations of the same set of thematic materials; finally, there is a crucial recurrence suggesting the infinitude of the form. Instead of creating an ill-conceived dichotomy between form as a secondary structure and the meaningful ‘narrative’ in negotiation with formal questions, I wish to regard form as a primary source of a work’s meaning. At the same time, I wish to regard the form of the movement as an efficient means of channelling its dialogue with the genre of scherzo. Listened to as a composer’s self-positioning in the field of the masters of symphony, the movement reveals Mahler’s successful attempt at breaking away from the Brucknerian model of scherzo and, at the same time, proudly parading his virtuosity in applying some elements of that model in a different context.