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We introduce a dynamic version of the graph coloring problem and prove its fixed-parameter tractability with respect to the edit-parameter. This is used to present a {\em turbo-charged} heuristic for the problem that works by combining the turbo-charging technique with other standard heuristic tools, including greedy coloring. The recently introduced turbo-charging idea is further enhanced in this paper by introducing a dynamic version of the so called {\em moment of regret} and {\em rollback points}. Experiments comparing our turbo-charging algorithm to other heuristics demonstrate its effectiveness. Our algorithm often produced results that were either exact or better than all the other available heuristics.

Made available in DSpace on 2018-08-01T22:32:50Z (GMT). No. of bitstreams: 1 tese_11626_Versão.final.dissertação_Monica.pdf: 1571291 bytes, checksum: 8826f060f7bbe1e2699161b1da126eb7 (MD5) Previous issue date: 2017-11-20 Este trabalho consiste em realizar um estudo aprofundado sobre semelhança de figuras planas, a partir de um conhecimento prévio dos conceitos básicos de geometria plana. Além da teoria, abordada nos três primeiros capítulos e voltada principalmente para professores de matemática, encontram-se também, nos três capítulos subsequentes, exercícios resolvidos tradicionalmente e também resolvidos utilizando o software GeoGebra, além de exercícios propostos juntamente com suas respectivas respostas esperadas.

International audience; The energy release rate of small cracks governs fatigue crack nucleation. A method is presented here to efficiently and accurately evaluate the energy release rate of such cracks, arbitrarily oriented, under general conditions of finite multiaxial loading. As a motivation, the dependence on crack length is then investigated. It is demonstrated that the energy release rate of small cracks is proportional to the crack length and that the proportionality factor is a function of the far-field parameters only. An attempt is then made to search for a general expression of this proportionality factor under simple loading conditions.

A qualitative characterization of 16 polycyclic aromatic hydrocarbons (PAHs) in pea seeds before and post gamma irradiation has been carried out using gas chromatography-mass spectrometry (GC-MS). Seeds were exposed to gamma irradiation at 1, 5, 10 and 15 kGy doses. PAHs were extracted and their concentrations were correlated with the peak height, at each dose and compared to control samples. PAHs peaks decreased with the increase of gamma irradiation dose. Total bacterial and total fungal counts decreased from 2.43 and 1.66 log10 cfu g-1, respectively (non-irradiated), to