Automatic Extraction of Subcategorization from Corpora

We describe a novel technique and implemented system for constructing a subcategorization dictionary from textual corpora. Each dictionary entry encodes the relative frequency of occurrence of a comprehensive set of subcategorization classes for English. An initial experiment, on a sample of 14 verbs which exhibit multiple complementation patterns, demonstrates that the technique achieves accuracy comparable to previous approaches, which are all limited to a highly restricted set of subcategorization classes. We also demonstrate that a subcategorization dictionary built with the system improves the accuracy of a parser by an appreciable amount.Comment: 8 pages; requires aclap.sty. To appear in ANLP-9

Apportioning Development Effort in a Probabilistic LR Parsing System through Evaluation

We describe an implemented system for robust domain-independent syntactic parsing of English, using a unification-based grammar of part-of-speech and punctuation labels coupled with a probabilistic LR parser. We present evaluations of the system's performance along several different dimensions; these enable us to assess the contribution that each individual part is making to the success of the system as a whole, and thus prioritise the effort to be devoted to its further enhancement. Currently, the system is able to parse around 80% of sentences in a substantial corpus of general text containing a number of distinct genres. On a random sample of 250 such sentences the system has a mean crossing bracket rate of 0.71 and recall and precision of 83% and 84% respectively when evaluated against manually-disambiguated analyses.Comment: 10 pages, 1 Postscript figure. To Appear in Proceedings of the Conference on Empirical Methods in Natural Language Processing, University of Pennsylvania, May 199

Corpus Annotation for Parser Evaluation

We describe a recently developed corpus annotation scheme for evaluating parsers that avoids shortcomings of current methods. The scheme encodes grammatical relations between heads and dependents, and has been used to mark up a new public-domain corpus of naturally occurring English text. We show how the corpus can be used to evaluate the accuracy of a robust parser, and relate the corpus to extant resources.Comment: 7 pages, LaTeX (uses eaclap.sty

Can Subcategorisation Probabilities Help a Statistical Parser?

Research into the automatic acquisition of lexical information from corpora is starting to produce large-scale computational lexicons containing data on the relative frequencies of subcategorisation alternatives for individual verbal predicates. However, the empirical question of whether this type of frequency information can in practice improve the accuracy of a statistical parser has not yet been answered. In this paper we describe an experiment with a wide-coverage statistical grammar and parser for English and subcategorisation frequencies acquired from ten million words of text which shows that this information can significantly improve parse accuracy.Comment: 9 pages, uses colacl.st

Delimitation Questions in United States v. California {100 S. Ct. 1994}

Whether the federal government or the coastal states have jurisdiction over coastal submerged lands has been litigated since 1945 in successively more refined forms

Disambiguating Nouns, Verbs, and Adjectives Using Automatically Acquired Selectional Preferences

Selectional preferences have been used by word sense disambiguation (WSD) systems as one source of disambiguating information. We evaluate WSD using selectional preferences acquired for English adjective—noun, subject, and direct object grammatical relationships with respect to a standard test corpus. The selectional preferences are specific to verb or adjective classes, rather than individual word forms, so they can be used to disambiguate the co-occurring adjectives and verbs, rather than just the nominal argument heads. We also investigate use of the one-senseper-discourse heuristic to propagate a sense tag for a word to other occurrences of the same word within the current document in order to increase coverage. Although the preferences perform well in comparison with other unsupervised WSD systems on the same corpus, the results show that for many applications, further knowledge sources would be required to achieve an adequate level of accuracy and coverage. In addition to quantifying performance, we analyze the results to investigate the situations in which the selectional preferences achieve the best precision and in which the one-sense-per-discourse heuristic increases performance

A redetermination of the specific heat of water between 10ºC and 20ºC

The first experiment which showed a quantitative relation between work and heat was described by Count Rumford in 1798. Since this time a large number of determinations of the “Mechanical Equivalent of Heat” have been made. Those made before the time of Joule need not be mentioned here, as in none of them were results of any reliability obtained. The accurate evaluation of the Equivalent dates from the researches of Joule, whose methods of experiment have been used in all the later work on the subject. Joule’s first experiments were a result of his discovery of the Law of Electrical Heating and were made by the electrical heating of water; but the large differences between the results given by this method and those obtained by the more direct method of frictional heating, led him to believe that the absolute values of the Electrical Standards were not sufficiently well known. He therefore abandoned the electrical method and obtained his final results by frictional heating

Paper Session II-B - STS-74 SRMS- Assisted Docking of Docking Module Demonstrates ISS Assembly Technique

Space station assembly was demonstrated, albeit on a smaller scale, on STS-74. This experience provided confidence in the ISS Flight 2A assembly method, in which Node 1 will be attached to the Orbiter Docking System (ODS) via SRMS-assisted (Shuttle Remote Manipulator System) docking; then the FGB will be attached to Node 1 in a similar fashion. For the Space Shuttle STS-74 mission, a means of attaching the passive Docking Module (DM) to the ODS was required. The SRMS was used to position and hold the DM above the ODS, while the downfiring Reaction Control System (RCS) thrusters were used to effect the docking. This type of operation had never been attempted with the SRMS before, so a comprehensive dynamic analysis of this operation was performed. A non real-time flex dynamics simulation program was developed to provide the capture statistics, structural loads, and dynamics for this operation. An automated Monte-Carlo approach was used to cover the envelope of expected initial docking conditions. The study showed that the STS-74 DM could be reliably installed on the ODS via SRMS-assisted docking and that the resulting structural loads were acceptable. Post-flight comparisons of the simulation vs. flight data showed that the simulation provided an accurate representation of the system