A hierarchical statistical framework for emergent constraints: application to snow-albedo feedback

Emergent constraints use relationships between future and current climate states to constrain projections of climate response. Here, we introduce a statistical, hierarchical emergent constraint (HEC) framework in order to link future and current climate with observations. Under Gaussian assumptions, the mean and variance of the future state is shown analytically to be a function of the signal-to-noise (SNR) ratio between data-model error and current-climate uncertainty, and the correlation between future and current climate states. We apply the HEC to the climate-change, snow-albedo feedback, which is related to the seasonal cycle in the Northern Hemisphere. We obtain a snow-albedo-feedback prediction interval of $(-1.25, -0.58)$ \%$K^{-1}$. The critical dependence on SNR and correlation shows that neglecting these terms can lead to bias and under-estimated uncertainty in constrained projections. The flexibility of using HEC under general assumptions throughout the Earth System is discussed.Comment: 19 pages, 5 Figure

Core Losses in Co-Rich Inductors with Tunable Permeability

High frequency, low loss power systems enable electrified aircraft propulsion. Filter inductors that reduce noise in high current systems can account for 50% of the motor drive mass. Efficient inductor cores with tunable permeability reduce system mass by producing less heat, that removes heat sink mass. Requirements for filter inductors vary based on the chosen topology, but all inductor cores must operate below saturation levels. As the saturation flux density is limited (less than ~2 T), high differential current applications require cores with low relative permeabilities. The large induced anisotropies possible in Co-rich metal amorphous nanocomposite materials enables gapless inductors with relative permeabilities down to ~20. These materials have fine grain size ~8nm with a faulted, close packed structure. The impact of different processing methods on core losses are presented along with comparison to other low permeability soft magnetic materials

Verb Argument Structure Alternations in Word and Sentence Embeddings

Verbs occur in different syntactic environments, or frames. We investigate whether artificial neural networks encode grammatical distinctions necessary for inferring the idiosyncratic frame-selectional properties of verbs. We introduce five datasets, collectively called FAVA, containing in aggregate nearly 10k sentences labeled for grammatical acceptability, illustrating different verbal argument structure alternations. We then test whether models can distinguish acceptable English verb--frame combinations from unacceptable ones using a sentence embedding alone. For converging evidence, we further construct LAVA, a corresponding word-level dataset, and investigate whether the same syntactic features can be extracted from word embeddings. Our models perform reliable classifications for some verbal alternations but not others, suggesting that while these representations do encode fine-grained lexical information, it is incomplete or can be hard to extract. Further, differences between the word- and sentence-level models show that some information present in word embeddings is not passed on to the downstream sentence embeddings

Manual of Roman Everyday Writing. Volume 1, Scripts and Texts

Volume 1 describes the kinds of documents that are written in Latin cursive script and tabulates the main published collections and individual items of texts in cursive script from across the Roman world, ranging in provenance from northern England to Africa, Egypt and Syria. The types of cursive script, conventionally labelled Old Roman Cursive (1st-3rd centuries) and New Roman Cursive (from the 3rd century) are illustrated, with layout of different kinds of documents, tables of letter forms and the most important abbreviations, signs and conventions. This makes important contributions to our knowledge of the origins and early history of Roman cursive as well as the long-standing debate among palaeographers about how and why the essential character of the scripts underwent obvious technical and stylistic changes in the course of the third century CE. A practice-based approach to the subject examines the evidence for the ways in which people may have learnt to read and write cursive in antiquity and the implications for the spread of literacy. For the modern reader, it provides a step-by-step guide to deciphering and interpreting Roman cursive texts, including video tutorials. Finally, it offers an exploration through text and video of the technologies of the digital age, including multispectral analysis and Reflectance Transformation Imaging, which have been pioneered at the Centre for the Study of Ancient Documents since the 1990s and have greatly improved the image-capturing techniques and the visibility of damaged documents written on wood, papyrus and various metals