In this survey (functional) compositions of weighted tree transformations computable by weighted extended top-down tree transducers are investigated. The existing results in the literature are explained and illustrated. It is argued, why certain compositions are not possible in the general case, and 3 informed conjectures provide an insight into potentially 3 new composition results that extend...

A query is determined by a view, if the result to the query can be reconstructed from the result of the view. We consider the problem of deciding for two given tree transformations, whether one is determined by the other. If the view transformation is induced by a tree transducer that may copy, then determinacy is undecidable, even for identity queries. For a large class of non-copying views, n...

abstract purpose - the aim of this paper is to describe the population ecology theory through fractal thinking, an emergent human operating system that is creative, adaptive, healthy, and evolutionary; furthermore, a parallel is drawn between the population ecology model and the fractal structure. top-down hierarchies are typically characterized by command and control systems of the authority t...

Top-down tree transducers with "-rules ("tdtt) are a restricted version of extended top-down tree transducers. They are implemented in the framework Tiburon and ful ll some criteria desirable in a machine translation model. However, they compute a class of transformations that is not closed under composition (not even for linear and nondeleting "tdtt). A composition construction that composes "...

We study normalization of deterministic sequential top-down tree-to-word transducers (stws), that capture the class of deterministic top-down nested-word to word transducers. We identify the subclass of earliest stws (estws) that yield unique normal forms when minimized. The main result of this paper is an effective normalization procedure for stws. It consists of two stages: we first convert a...

 Let T and S be ordered, labeled trees. We say that S is included in T if there is a sequence of delete operations performed on T, which make T isomorphic to S. In this paper, we propose a top-down algorithm for this problem, which needs only O(|T|⋅|leaves(S)|) time and O(|T| + |S|) space.

The power of top-down, bottom-up, and tree-to-graph-to-tree transducers (tgt transducers) to compute translations from hyperedge-replacement algebras into edge-replacement algebras is investigated. Compositions of top-down and bottom-up tree transducers are too weak if the operations in the target algebra are powerful enough to deene all series-parallel graphs, 2-trees, or related types of grap...

Regular tree grammars can be used to generate graphs, by generating expressions that denote graphs. Top-down and bottom-up tree transducers are a tool for proving properties of such graph generating tree grammars.

It is shown that top-down tree transducers are as powerful as sharing-free tree-to-graph-to-tree transducers as far as the computation of functions is considered whose codomain is a semiring.

For Reliable Multicast Service, to use tree hierarchy can be a promising solution to avoid well-known ACKimplosion. However, to build an efficient ACK-tree is very difficult for IP Multicast because it does not provide explicit membership and routing topology information to upper layer protocol. Due to the difficulties, not much study has been done on the control tree configuration yet, while i...