Comparison by Conversion: Reverse-Engineering UCCA from Syntax and Lexical Semantics

Building robust natural language understanding systems will require a clear characterization of whether and how various linguistic meaning representations complement each other. To perform a systematic comparative analysis, we evaluate the mapping between meaning representations from different frameworks using two complementary methods: (i) a rule-based converter, and (ii) a supervised delexicalized parser that parses to one framework using only information from the other as features. We apply these methods to convert the STREUSLE corpus (with syntactic and lexical semantic annotations) to UCCA (a graph-structured full-sentence meaning representation). Both methods yield surprisingly accurate target representations, close to fully supervised UCCA parser quality---indicating that UCCA annotations are partially redundant with STREUSLE annotations. Despite this substantial convergence between frameworks, we find several important areas of divergence.Comment: COLING 2020 camera read

The Earliest Lead Object in the Levant.

In the deepest section of a large complex cave in the northern Negev desert, Israel, a bi-conical lead object was found logged onto a wooden shaft. Associated material remains and radiocarbon dating of the shaft place the object within the Late Chalcolithic period, at the late 5th millennium BCE. Based on chemical and lead isotope analysis, we show that this unique object was made of almost pure metallic lead, likely smelted from lead ores originating in the Taurus range in Anatolia. Either the finished object, or the raw material, was brought to the southern Levant, adding another major component to the already-rich Late Chalcolithic metallurgical corpus known to-date. The paper also discusses possible uses of the object, suggesting that it may have been used as a spindle whorl, at least towards its deposition

View of Ashalim Cave in its desert environment.

<p>The vertical entrance to the cave is located in front of the standing figure.</p

The Lead object.

<p>The lead object with shaft <i>insitu</i> at Ashalim Cave.</p

The Ashalim Cave lead object.

<p>The Ashalim Cave lead object.</p

Plan of Ashalim Cave.

<p>The plan of Ashalim Cave with the location of the lead object marked by a dot.</p

Results of lead isotope analysis.

<p>Lead isotope ratios of the Ashalim Cave lead object plotted against ores from selected regions. Details and references are provided in the text.</p

Normalized trace element concentrations (ppm) measured by WDS.

<p>Normalized trace element concentrations (ppm) measured by WDS.</p