Treebank Embedding Vectors for Out-of-domain Dependency Parsing

A recent advance in monolingual dependency parsing is the idea of a treebank embedding vector, which allows all treebanks for a particular language to be used as training data while at the same time allowing the model to prefer training data from one treebank over others and to select the preferred treebank at test time. We build on this idea by 1) introducing a method to predict a treebank vector for sentences that do not come from a treebank used in training, and 2) exploring what happens when we move away from predefined treebank embedding vectors during test time and instead devise tailored interpolations. We show that 1) there are interpolated vectors that are superior to the predefined ones, and 2) treebank vectors can be predicted with sufficient accuracy, for nine out of ten test languages, to match the performance of an oracle approach that knows the most suitable predefined treebank embedding for the test set.Comment: Camera ready for ACL 202

Disconnected Elementary Band Representations, Fragile Topology, and Wilson Loops as Topological Indices: An Example on the Triangular Lattice

In this work, we examine the topological phases that can arise in triangular lattices with disconnected elementary band representations. We show that, although these phases may be "fragile" with respect to the addition of extra bands, their topological properties are manifest in certain nontrivial holonomies (Wilson loops) in the space of nontrivial bands. We introduce an eigenvalue index for fragile topology, and we show how a nontrivial value of this index manifests as the winding of a hexagonal Wilson loop; this remains true even in the absence of time-reversal or sixfold rotational symmetry. Additionally, when time-reversal and twofold rotational symmetry are present, we show directly that there is a protected nontrivial winding in more conventional Wilson loops. Crucially, we emphasize that these Wilson loops cannot change without closing a gap to the nontrivial bands. By studying the entanglement spectrum for the fragile bands, we comment on the relationship between fragile topology and the "obstructed atomic limit" of B. Bradlyn et al., Nature 547, 298--305 (2017). We conclude with some perspectives on topological matter beyond the K-theory classification.Comment: 13 pages, 10 figures v2. accepted versio

Bishops in Flight

Flight during times of persecution has a long and fraught history in early Christianity. In the third century, bishops who fled were cowards or, worse yet, heretics. On the face of it, it meant denial of Christ and thus betrayal of the faith and its community. But, by the fourth century, the terms of persecution changed as Christianity became the favored cult of the Roman Empire. Prominent Christians who fled and hence survived became founders and influencers of Christianity over time. Bishops in Flight examines the various ways these episcopal leaders both appealed to and altered the discourse of Christian flight to defend their status as purveyors of Christian truth even when their exiles appeared to condemn them. It illuminates how profoundly Christian authors deployed theological discourse and the rhetoric of heresy to respond to the phenomenal political instability of the fourth and fifth centuries

Bishops in Flight

Flight during times of persecution has a long and fraught history in early Christianity. In the third century, bishops who fled were cowards or, worse yet, heretics. On the face of it, it meant denial of Christ and thus betrayal of the faith and its community. But, by the fourth century, the terms of persecution changed as Christianity became the favored cult of the Roman Empire. Prominent Christians who fled and hence survived became founders and influencers of Christianity over time. Bishops in Flight examines the various ways these episcopal leaders both appealed to and altered the discourse of Christian flight to defend their status as purveyors of Christian truth even when their exiles appeared to condemn them. It illuminates how profoundly Christian authors deployed theological discourse and the rhetoric of heresy to respond to the phenomenal political instability of the fourth and fifth centuries

Quantum partially observable Markov decision processes

We present quantum observable Markov decision processes (QOMDPs), the quantum analogs of partially observable Markov decision processes (POMDPs). In a QOMDP, an agent is acting in a world where the state is represented as a quantum state and the agent can choose a superoperator to apply. This is similar to the POMDP belief state, which is a probability distribution over world states and evolves via a stochastic matrix. We show that the existence of a policy of at least a certain value has the same complexity for QOMDPs and POMDPs in the polynomial and infinite horizon cases. However, we also prove that the existence of a policy that can reach a goal state is decidable for goal POMDPs and undecidable for goal QOMDPs.National Science Foundation (U.S.) (Grant 0844626)National Science Foundation (U.S.) (Grant 1122374)National Science Foundation (U.S.) (Waterman Award

Bearing the risk : learning to be drier mid-river

This paper investigates learning related to the phenomena of drying over the past decade in the southern Murray-Darling Basin in Australia, as perceived in a mid-river site within the western Riverina of New South Wales, Australia. The insights from audio-recorded interviews, with a wide range of adults across the water-dependent community, mostly relate to the catchment of the&nbsp; Murrumbidgee River in the Shire of Hay. Our overarching theme is about how&nbsp; people are learning about, understanding and bearing the risks, of what is widely regarded as a prolonged drought. For some, the learning is about how to cope with less water in the Basin, and particularly from the river, as predicted in the climate change literature. Our narrative-based, empirical research registers the felt experience of those located, in situ, as a severe &lsquo;irrigation drought&rsquo; extends into 2009. The paper dramatises the many obstacles to learning how to think and act differently, in difficult and rapidly changing ecosocial circumstances.<br /

The emittance of space radiator materials measured at elevated temperatures

The spectral emittances of textured space radiator materials between 1.7 and 14.7 micrometer have been evaluated at room temperature and elevated temperature (630 C) in air. Heating in air caused a permanent increase in spectral emittance for all materials tested: HCl/ion beam textured 304 stainless steel, untextured Ti (6 percent Al, 4 percent V), and sandblasted Ti (6 percent Al, 4 percent V). Changes in the surface chemistry and/or surface morphology of these materials were also observed. Elevated temperature spectral emittance was measured in an argon atmosphere and compared to the measurements in air. Similarity between the room temperature and elevated temperature spectral emittance measurements was also investigated, and limited agreement was found