A finitely generated group is called a Church-Rosser group (growing contextsensitive group) if it admits a finitely generated presentation for which the word problem is a Church-Rosser (growing context-sensitive) language. Although the ChurchRosser languages are incomparable to the context-free languages under set inclusion, they strictly contain the class of deterministic context-free language...

There has been recent interest in applying cognitively or empirically motivated bounds on recursion depth to limit the search space of grammar induction models (Ponvert et al., 2011; Noji and Johnson, 2016; Shain et al., 2016). This work extends this depth-bounding approach to probabilistic context-free grammar induction (DB-PCFG), which has a smaller parameter space than hierarchical sequence ...

Predicting the secondary structure of RNA molecules from the knowledge of the primary structure (the sequence of bases) is still a challenging task. There are algorithms that provide good results e.g. based on the search for an energetic optimal configuration. However the output of such algorithms does not always give the real folding of the molecule and therefore a feature to judge the reliabi...

Second-order abstract categorial grammars (de Groote 2001) and hyperedge replacement grammars (see Engelfriet 1997) are two natural ways of generalizing “context-free” grammar formalisms for string and tree languages. It is known that the string generating power of both formalisms is equivalent to (non-erasing) multiple context-free grammars (Seki et al. 1991) or linear context-free rewriting s...

L systems generalise context-free grammars by incorporating parallel rewriting, and generate languages such as EDT0L and ET0L that are strictly contained in the class of indexed languages. In this paper we show that many of the languages naturally appearing in group theory, and that were known to be indexed or context-sensitive, are in fact ET0L and in many cases EDT0L. For instance, the langua...

It is a very important to develop context-aware systems that can handle, at the same time, multiple heterogeneous applications that require different contexts with different levels of abstraction. This paper proposes a framework for such systems. To handle the heterogeneity of the context required by the applications, we introduce a user activity context detection method based on the combinatio...

Context-aware computing is a recent approach to tailoring technology to the user’s context. As part of the vision for ubiquitous computing, it describes computing applications that change or adapt according to environmental characteristics. Research within the field have mainly focused on technical possibilities for representing a context in the use situation, however, not many context-aware ap...

In this paperwe consider the problemof efficient computation of cross-moments of a vector randomvariable represented by a stochastic context-free grammar. Two types of cross-moments are discussed. The sample space of the first one is the set of all derivations of the context-free grammar, and the sample space of the second one is the set of all derivations which generate a string belonging to t...

Context awareness enables smart service discovery and adaptation for mobile and wireless hosts. The contextual data is acquired from sensors present in the smart space, which may be absent. The inherent noisy nature of wireless environments does not guarantee the gathering of correct data. A history module is thus required in conjunction with existing context-aware systems that overcomes these ...

Recently, the use of syntax has very effectively improved machine translation (MT) quality in many text translation tasks. However, using syntax in speech translation poses additional challenges because of disfluencies and other spoken language phenomena, and of errors introduced by automatic speech recognition (ASR). In this paper, we investigate the effect of using syntax in a large-scale aud...