O(2, 2) transformations and the string Geroch group

String Quantum Symmetries and the Sl(2,z Z) Group

We prove, using arguments relying only on the ”special Kähler” structure of the moduli space of the Calabi-Yau three-fold, that in the case of one single modulus the quantum modular group of the string effective action corresponding to Calabi-Yau vacua can not be SL(2,ZZ). 1 A lot of effort has been recently devoted in order to understand the local and global properties of the moduli space of t...

First-order Definable String Transformations

The connection between languages defined by computational models and logic for languages is well-studied. Monadic second-order logic and finite automata are shown to closely correspond to each-other for the languages of strings, trees, and partial-orders. Similar connections are shown for first-order logic and finite automata with certain aperiodicity restriction. Courcelle in 1994 proposed a w...

String Transformations In The Request System

Heuristical Coding of String Transformations

As a part of a study on statistical grammar learning, the word inflection is investigated in this article. The word inflection is used to create different grammatical instances of the word. In this paper, the different coding alternatives to describe the strings and the string transformations are investigated. The proposed methods are tested on a natural language, the Hungarian language.

Learning String Transformations From Examples

“Robert” and “Bob” refer to the same first name but are textually far apart. Traditional string similarity functions do not allow a flexible way to account for such synonyms, abbreviations and aliases. Recently, string transformations have been proposed as a mechanism to make matching robust to such variations. However, in many domains, identifying an appropriate set of transformations is chall...