76 research outputs found
Natural Language Processing
The subject of Natural Language Processing can be considered in both broad and narrow senses. In the broad sense, it covers processing issues at all levels of natural language understanding, including speech recognition, syntactic and semantic analysis of sentences, reference to the discourse context (including anaphora, inference of referents, and more extended relations of discourse coherence and narrative structure), conversational inference and implicature, and discourse planning and generation. In the narrower sense, it covers the syntactic and semantic processing sentences to deliver semantic objects suitable for referring, inferring, and the like. Of course, the results of inference and reference may under some circumstances play a part in processing in the narrow sense. But the processes that are characteristic of these other modules are not the primary concern
The design and implementation of Object Grammars
An Object Grammar is a variation on traditional BNF grammars, where the notation is extended to support declarative bidirectional mappings between text and object graphs. The two directions for interpreting Object Grammars are parsing and formatting. Parsing transforms text into an object graph by recognizing syntactic features and creating the corresponding object structure. In the reverse direction, formatting recognizes object graph features and generates an appropriate textual presentation. The key to Object Grammars is the expressive power of the mapping, which decouples the syntactic structure from the graph structure. To handle graphs, Object Grammars support declarative annotations for resolving textual names that refer to arbitrary objects in the graph structure. Predicates on the semantic structure provide additional control over the mapping. Furthermore, Object Grammars are compositional so that languages may be defined in a modular fashion. We have implemented our approach to Object Grammars as one of the foundations of the Ens (o) over bar system and illustrate the utility of our approach by showing how it enables definition and composition of domain-specific languages (DSLs). (C) 2014 Elsevier B.V. All rights reserved.</p
An accurate prefetching policy for object oriented systems
PhD ThesisIn the latest high-performance computers, there is a growing requirement for
accurate prefetching(AP) methodologies for advanced object management schemes
in virtual memory and migration systems. The major issue for achieving this goal is that
of finding a simple way of accurately predicting the objects that will be referenced in
the near future and to group them so as to allow them to be fetched same time. The
basic notion of AP involves building a relationship for logically grouping related
objects and prefetching them, rather than using their physical grouping and it relies on
demand fetching such as is done in existing restructuring or grouping schemes. By this,
AP tries to overcome some of the shortcomings posed by physical grouping methods.
Prefetching also makes use of the properties of object oriented languages to
build inter and intra object relationships as a means of logical grouping. This thesis
describes how this relationship can be established at compile time and how it can be
used for accurate object prefetching in virtual memory systems. In addition, AP
performs control flow and data dependency analysis to reinforce the relationships and
to find the dependencies of a program. The user program is decomposed into
prefetching blocks which contain all the information needed for block prefetching such
as long branches and function calls at major branch points.
The proposed prefetching scheme is implemented by extending a C++
compiler and evaluated on a virtual memory simulator. The results show a significant
reduction both in the number of page fault and memory pollution. In particular, AP
can suppress many page faults that occur during transition phases which are
unmanageable by other ways of fetching. AP can be applied to a local and distributed
virtual memory system so as to reduce the fault rate by fetching groups of objects at the
same time and consequently lessening operating system overheads.British Counci
Grammars and Processors
The paper discusses the role of grammars in sentence processing, and explores some consequences of the Strong Competence Hypothesis of Bresnan and Kaplan for combinatory theories of grammar
Generating Programming Environments with Integrated Text and Graphics for VLSI Design Systems
The constant improvements in device integration, the development of new technologies
and the emergence of new design techniques call for flexible, maintainable
and robust software tools. The generic nature of compiler-compiler systems,
with their semi-formal specifications, can help in the construction of those tools.
This thesis describes the Wright editor generator which is used in the synthesis
of language-based graphical editors (LBGEs). An LBGE is a programming
environment where the programs being manipulated denote pictures. Editing
actions can be specified through both textual and graphical interfaces. Editors
generated by the Wright system are specified using the formalism of attribute
grammars.
The major example editor in this thesis, Stick-Wright, is a design entry system
for the construction of VLSI circuits. Stick-Wright is a hierarchical symbolic
layout editor which exploits a combination of text and graphics in an interactive
environment to provide the circuit designer with a tool for experimenting with
circuit topologies. A simpler system, Pict-Wright: a picture drawing system, is
also used to illustrate the attribute grammar specification process.
This thesis aims to demonstrate the efficacy of formal specification in the
generation of software-tools. The generated system Stick-Wright shows that a
text/graphic programming environment can form the basis of a powerful VLSI
design tool, especially with regard to providing the designer with immediate
graphical feedback. Further applications of the LBGE generator approach to
system design are given for a range of VLSI design activities
Neural Combinatory Constituency Parsing
東京都立大学Tokyo Metropolitan University博士(情報科学)doctoral thesi
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