Automaton-based parsing for lexicalized grammars

In wide-coverage lexicalized grammars many of the elementary structures have substructures in common. This means that during parsing some of the computation associated with different structures is duplicated. This paper explores ways in which the grammar can be precompiled into finite state automata so that some of this shared structure results in shared computation at run-time. 1 Introduction This paper investigates grammar precompilation techniques aimed at improving the parsing performance of lexicalized grammars. In a wide-coverage lexicalized grammar, such as the XTAG grammar (XTAG-Group, 1995), many of the elementary structures 1 have substructures in common. If such structures are viewed as independent by a parsing algorithm, the computation associated with their shared structure may be duplicated. This paper explores ways in which the grammar can be precompiled so that some of this shared structure results in shared computation at run-time. We assume as a starting point a co..

Encoding Lexicalized Tree Adjoining Grammars with a Nonmonotonic Inheritance Hierarchy

This paper shows how DATR, a widely used formal language for lexical knowledge representation, can be used to define an LTAG lexicon as an inheritance hierarchy with internal lexical rules. A bottom-up featural encoding is used for LTAG trees and this allows lexical rules to be implemented as covariation constraints within feature structures. Such an approach eliminates the considerable redundancy otherwise associated with an LTAG lexicon.Comment: Latex source, needs aclap.sty, 8 page

A structure-sharing parser for lexicalized grammars

In wide-coverage lexicalized grammars many of the elementary structures have substructures in common. This means that in conventional parsing algorithms some of the computation associated with different structures is duplicated. In this paper we describe a precompilation technique for such grammars which allows some of this computation to be shared. In our approach the elementary structures of the grammar are transformed into finite state automata which can be merged and minimised using standard algorithms, and then parsed using an automatonbased parser. We present algorithms for constructing automata from elementary structures, merging and minimising them, and string recognition and parse recovery with the resulting grammar

`Lexical rules' are just lexical rules

The question we address in this paper is whether `Lexical Rules' deserve their grand status, a status that is often conveyed by a special purpose formalism and/or a separate component, one that may even be external to the lexicon proper. We will argue that they do not and that a lexical knowledge representation language that is as expressive as it needs to be for other lexical purposes will, ipso facto, be expressive enough to encode `Lexical Rules' internally as lexical rules. Such internal encoding is not only possible but also desirable since `Lexical Rules' will then automatically acquire other characteristics which are now standardly associated with common or garden lexical rules, including inheritance, generalization by default, and the ability to relate lexical information from different levels of linguistic description. We give examples of what we take to be instances of common or garden lexical rules and then show how the same formal machinery provides for the stateme..

Location of Mach Discs and Diamonds Supersonic Air Jets

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77542/1/AIAA-3788-127.pd

The Grizzly, August 28, 2008

Ursinus Welcomes Class of 2012: Largest in History • Students Embrace Unique Summer Research Opportunity • Academic Insight into the Lighter Side of Ramadan • That Dream Internship Just Might be Within Your Reach • Berman Exhibitions: Watercolors and Working Women • New Dining Options at Ursinus a Matter of Convenience • UC Theater and Dance Departments Have Lined Up a Full Season for Review • Opinions: Obama-nomics for the United States? No Thank You • UC Versus the Centennial Conference • UCXC Hits the Ground Runninghttps://digitalcommons.ursinus.edu/grizzlynews/1765/thumbnail.jp

The Challenges of First-in-Human Stem Cell Clinical Trials: What Does This Mean for Ethics and Institutional Review Boards?

Stem cell-based clinical interventions are increasingly advancing through preclinical testing and approaching clinical trials. The complexity and diversity of these approaches, and the confusion created by unproven and untested stem cell-based "therapies," create a growing need for a more comprehensive review of these early-stage human trials to ensure they place the patients at minimal risk of adverse events but are also based on solid evidence of preclinical efficacy with a clear scientific rationale for that effect. To address this issue and supplement the independent review process, especially that of the ethics and institutional review boards who may not be experts in stem cell biology, the International Society for Stem Cell Research (ISSCR) has developed a set of practical questions to cover the major issues for which clear evidence-based answers need to be obtained before approving a stem cell-based trial