A machine translation system is said to be complete if all expressions that are correct according to the source-language grammar can be translated into the target language. This paper addresses the completeness issue for compositional machine translation in general, and for compositional machine translation of context-free grammars in particular. Conditions that guarantee translation completene...

Context-aware systems must be able to deal with uncertain context information. We propose a generic context architecture and representation that incorporates the uncertainty of context elements in terms of upper and lower bounds of probabilities. It is shown how opinion nets can be used to reason with these upper and lower bound probabilities. In this way it is possible to combine ambiguous or ...

We introduce a hierarchy of monotonic rewriting automata with a restart operation and show that its deterministic version collapses in a sequence of characterizations of deterministic context-free languages. The nondeterministic version of it gives a proper hierarchy of classes of languages with the class of context-free languages on the top.

Context-aware systems acquire and integrate multi-faceted knowledge about their environments in order to make decisions. A number of attempts to build frameworks for context-aware systems have been made, but these have not provided adequate support for context-aware access control. In this paper, we present a framework for context-aware access control and its prototype implementation. The frame...

In this paper we examine the problem of extracting schema-conforming metadata out from HTML sources. A technique founded on semistructured data analysis is explained. It is based on the combination of HTML styles, which abstract the visual characteristics of documents, and document-oriented context-free grammar, which provide structural information. This technique is flexible enough to be appli...

Being context-ware will improve how software adapts to dynamic changes influenced by various factors during the operation of the software. Context-aware techniques have been widely applied in different types of applications, but still are limited to small scale or single-organizational environments due to the lack of well-agreed interfaces, protocols, and models for exchanging context data. Web...

We apply the idea of weight pushing (Mohri, 1997) to CKY parsing with fixed context-free grammars. Applied after rule binarization, weight pushing takes the weight from the original grammar rule and pushes it down across its binarized pieces, allowing the parser to make better pruning decisions earlier in the parsing process. This process can be viewed as generalizing weight pushing from transd...

Standard models of language learning are concerned with weak learning: the learner, receiving as input only information about the strings in the language, must learn to generalise and to generate the correct, potentially infinite, set of strings generated by some target grammar. Here we define the corresponding notion of strong learning: the learner, again only receiving strings as input, must ...

This paper presents a framework for building user interfaces for context-aware service management. It enables us to easily deploy context-aware services at computers through user-friendly manipulations to edit documents and monitor changes and services in the real world. It is constructed as a compound document framework whose the structural composition of visual components can be adapted to ch...

Probabilistic Context-Free Grammars have been unsuccessful in learning natural language, due to the complexity of the task. Considerable research has been conducted into methods of reducing the complexity of PCFG learning. This paper reports the progress of work in extending one particular method of constraining PCFG learning providing partial grammars to improve rule generation. We discuss wha...