A context-free grammar is a single-tree grammar (STG) if every nonterminal symbol has at most one production rule whose right hand side contains nonterminal symbols. Various properties of this class of grammars are studied. Although most properties of STG’s are undecidable, every linear STG generates a bounded language and a deterministic context-free language, so most properties of linear STG’...

because of the dispersion of activities in big cities, employing highways as the most important connecting way is indispensable. in today world, highways are connection arteries of cities transporting people to their social activities. because of continual use of highway, their walls prepare a context for conveying many social, cultural, economic, etc concepts. that is why most economic promoti...

Mandatory access control models have traditionally been employed as a robust security mechanism in multilevel security environments such as military domains. In traditional mandatory models, the security classes associated with entities are context-insensitive. However, context-sensitivity of security classes and flexibility of access control mechanisms may be required especially in pervasive c...

This review surveys research on second language vocabulary teaching and learning since1999. It first considers the distinction between incidental and intentional vocabulary learning.Although learners certainly acquire word knowledge incidentally while engaged in variouslanguage learning activities, more direct and systematic study of vocabulary is also required.There is a discussion of how word...

We investigate how to automatically verify that resources such as files are not used improperly or unsafely by a program. We employ a mixture of compile-time analysis and run-time testing to verify that a program conforms to a resource usage policy specified by a deterministic finite state automata (DFA) which details allowed sequences of operations on resources. Our approach has four main phas...

Linear Context-Free Rewriting System (LCFRS) is an extension of Context-Free Grammar (CFG) in which a non-terminal can dominate more than a single continuous span of terminals. Probabilistic LCFRS have recently successfully been used for the direct data-driven parsing of discontinuous structures. In this paper we present a parser for binary PLCFRS of fan-out two, together with a novel monotonou...

Many mathematicians would agree that, had it not been for symmetric encryption, the improvement of context-free grammar might never have occurred. In our research, we confirm the exploration of Moore’s Law, which embodies the natural principles of complexity theory. ANTIAR, our new system for collaborative algorithms, is the solution to all of these obstacles.

The world is increasingly equipped with high-capacity, interconnected, mobile and embedded computing devices. Context-awareness provides an attractive approach to personalize applications such that they better suit the user’s needs in this rich computing environment. Context-aware applications use context information, offered by context sources, to adapt their behavior to the situation at hand....

A tree controlled grammar is specified as a pair (G,G) where G is a context-free grammar and G is a regular grammar. Its language consists of all terminal words with a derivation in G such that all levels of the corresponding derivation tree – except the last level – belong to L(G). We define the nonterminal complexity Var(H) of H = (G,G) as the sum of the numbers of nonterminals of G and G. In...

It has been suggested that, in certain circumstances, it might be useful for a grammar writer to annotate which rules are to be used bottom-up and which are to be used top-down within a parser, using a bidirectional variant of the active chart parsing technique. The formal properties of such systems have not been fully explored. One limitation of this mixed strategy technique is that certain an...