Applications of combinatorics to statics—a second survey

AbstractSome recent results are presented, concerning the algorithmic aspects of 2-dimensional generic rigidity, and 1-story buildings as tensegrity frameworks. Most of these results were obtained after the completion of the first survey (Recski, 1984) for a ‘Winter School’ organized by the late Professor Z. Frolík. Results in Sections 3 and 4 of the first survey are used throughout

Hungarian noun phrase extraction using rule-based and hybrid methods

We implement and revise Kornai's grammar of Hungarian NPs [11] to create a parser that identifies noun phrases in Hungarian text. After making several practical amendments to our morphological annotation system of choice, we proceed to formulate rules to account for some specific phenomena of the Hungarian language not covered by the original rule system. Although the performance of the final parser is still inferior to state-of-the-art machine learning methods, we use its output successfully to improve the performance of one such system

Book reviews

Daniel Currie Hall: The role and representation of contrast in phonological theory. University of Toronto, Toronto, 2007, 277 pp. ; David Odden: Introducing phonology. Cambridge University Press, Cambridge, 2005, 348 pp

Computer-assisted error analysis: A study of prepositional errors in the Brazilian subcomponent of the international corpus of learner english (Br-ICLE)

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão.Programas para, a análise de texto para microcomputadores já estão disponíveis há algum tempo. A técnica de análise de erros preposicionais auxiliada por computador, um nov

Applications of combinatorics to statics—rigidity of grids

AbstractThe infinitesimal rigidity (or briefly rigidity) of a bar-and-joint framework (in any dimension) can be formulated as a rank condition of the so-called rigidity matrix. If there are n joints in the framework then the size of this matrix is O(n), so the time complexity of determining its rank is O(n3). But in special cases we can work with graph and matroid theoretical models from which very fast and effective algorithms can be obtained. At first the case of planar square grids will be presented where they can be made rigid with diagonal rods and cables in the squares, and with long rods and cables which may be placed between any two joints of the grid. Then we will consider the one- and multi-story buildings, and finally some other results and algorithms