tailieunhanh - Báo cáo khoa học: "THE SYNTAX AND SEMANTICS OF USER-DEFINED MODIFIERS IN A TRANSPORTABLE NATURAL LANGUAGE PROCESSOR"

The Layered Domain Class system (LDC) is an experimental natural language processor being developed at Duke University which reached the prototype stage in M a y of 1983. Its primary goals are (I) to provide English-language retrieval capabilities for structured but unnormaUzed data files created by the user, (2) to allow very complex semantics, in terms of the information directly available from the physical data file; and (3) to enable users to customize the system to operate with new types of data. In this paper we shall discuss (a) the types of modifiers LDC provides for; (b) h o. | THE SYNTAX AND SEMANTICS OF USER-DEFINED MODIFIERS IN A TRANSPORTABLE NATURAL LANGUAGE PROCESSOR Bruce w. Ballard Dept of Computer Science Duke University Durham . 27706 ABSTRACT The Layered Domain Class system LDC is an experimental natural language processor being developed at Duke University which reached the prototype stage in May of 1983. Its primary goals are 1 to provide English-language retrieval capabilities for structured but unnormalized data files created by the user 2 to allow very complex semantics in terms of the information directly available from the physical data file and 3 to enable users to customize the system to operate with new types of data. In this paper we shall discuss a the types of modifiers LDC provides for b how information about the syntax and semantics of modifiers is obtained from users and c how this information is used to process English inputs. I INTRODUCTION The Layered Domain Class system LDC is an experimental natural language processor being developed at Duke University. In this paper we concentrate on the typjs of modifiers provided by LDC and the methods by which the system acquires information about the syntax and semantics of user-defined modifiers. A more complete description is available in 4 5 and further details on matters not discussed in this paper can be found in 1 2 6 8 9 . The LDC system is made up of two primary components. First the knowledge acquisition component whose job is to find out about the vocabulary and semantics of the language to be used for a new domain then inquire about the composition of the underlying input file. Second the User-Phase Processor which enables a user to obtain statistical reductions on his or her data by typed English inputs. The top-level design of the User-Phase processor involves a linear sequence of modules for scanning the input and looking up each token in the dictionary parsing the scanned input to determine its syntactic structure translation of the parsed input into