I t is wel] known tha t context-sensitive languages can be generated by means of monotonic grammars (see Ginsburg, Greibach, 1966) i.e. grammars whose rules have the form f --~ g, where I f ] , the length of f, is not greater than I g I . Such a g rammar generates the language, but almost no grammatical structure of the language is given. When such a structure is also investigated the original ...

We prove an analog of Parikh’s theorem for weighted context-free grammars over commutative, idempotent semirings, and exhibit a stochastic context-free grammar with behavior that cannot be realized by any stochastic right-linear context-free grammar. Finally, we show that every unary stochastic context-free grammar with polynomially-bounded ambiguity has an equivalent stochastic right-linear co...

We prove an analog of Parikh’s theorem for weighted context-free grammars over commutative, idempotent semirings, and exhibit a stochastic context-free grammar with behavior that cannot be realized by any stochastic right-linear context-free grammar. Finally, we show that every unary stochastic context-free grammar with polynomially-bounded ambiguity has an equivalent stochastic right-linear co...

A derivation step in a Graph Interpolation Grammar has the effect of scanning an input token. This feature, which aims at emulating the incrementality of the natural parser, restricts the formal power of GIGs. This contrasts with the fact that the derivation mechanism involves a context-sensitive device similar to tree adjunction in TAGs. The combined effect of input-driven derivation and restr...

In context-aware systems, one of the main challenges is how to model context uncertainty well, since perceived context always yields uncertainty and ambiguity with consequential effect on the performance of context-aware system. To handle uncertainty in context-aware systems, firstly, we should know from where uncertainty comes. In this paper, we argue that uncertainty comes from several source...

By a “tree-bank grammar” we mean a context-free grammar created by reading the production rules directly from hand-parsed sentences in a tree bank. Common wisdom has it that such grammars do not perform we& though we know of no published data on the issue. The primary purpose of this paper is to show that the common wisdom is wrong. In particular, we present results on a tree-bank grammar based...

In Europe, we observe an increasing number of people with health problems, who could theoretically receive care outside of a hospital when their condition could be properly monitored. Not being able to provide this monitoring leads to an increasing pressure on an already overcrowded hospital system and increased costs. Ubiquitous technology on top of a high-quality IT infra-structure has alread...

A description will be given of a procedure to asslgn the most likely probabilitles to each of the rules of a given context-free grammar. The grammar developed by S. Kuno at Harvard University was picked as the basis and was successfully augmented with rule probabilities. A brief exposition of the method with some preliminary results, whenused as a device for disamblguatingparsing English texts ...