Parameterized Complexity of Equitable Coloring

A graph on $n$ vertices is equitably $k$-colorable if it is $k$-colorable and every color is used either $\left\lfloor n/k \right\rfloor$ or $\left\lceil n/k \right\rceil$ times. Such a problem appears to be considerably harder than vertex coloring, being $\mathsf{NP\text{-}Complete}$ even for cographs and interval graphs. In this work, we prove that it is $\mathsf{W[1]\text{-}Hard}$ for block graphs and for disjoint union of split graphs when parameterized by the number of colors; and $\mathsf{W[1]\text{-}Hard}$ for $K_{1,4}$-free interval graphs when parameterized by treewidth, number of colors and maximum degree, generalizing a result by Fellows et al. (2014) through a much simpler reduction. Using a previous result due to Dominique de Werra (1985), we establish a dichotomy for the complexity of equitable coloring of chordal graphs based on the size of the largest induced star. Finally, we show that \textsc{equitable coloring} is $\mathsf{FPT}$ when parameterized by the treewidth of the complement graph

Social awareness in pervasive communities for collaborative work

Future pervasive environments will take into consideration physical and digital social relations. Nowadays it is important use to collective intelligence, where the interpretation of context information can be harnessed as input for context-aware applications, especially for group collaboration. The use of collective intelligence represents new possibilities but also new challenges in terms of collective information for adaptability and personalization in intelligent environments. This paper presents a collaborative context-aware framework focusing on social matching capabilities for session formation in collaborative activities

Deciphering M-T diagram of shape memory Heusler alloys: reentrance, plateau and beyond

We present our recent results on temperature behaviour of magnetization observed in Ni_47Mn_39In_14 Heusler alloys. Three regions can be distinguished in the M-T diagram: (I) low temperature martensitic phase (with the Curie temperature T_CM = 140 K), (II) intermediate mixed phase (with the critical temperature T_MS = 230 K) exhibiting a reentrant like behavior (between T_CM and T_MS) and (III) high temperature austenitic phase (with the Curie temperature T_CA = 320 K) exhibiting a rather wide plateau region (between T_MS and T_CA). By arguing that powerful structural transformations, causing drastic modifications of the domain structure in alloys, would also trigger strong fluctuations of the order parameters throughout the entire M-T diagram, we were able to successfully fit all the data by incorporating Gaussian fluctuations (both above and below the above three critical temperatures) into the Ginzburg-Landau scenario

Anatomia de algumas ocorrências de gemas e seu enquadramento em protocolos de ordenamento territorial – contributo para uma reflexão sobre o estatuto dos depósitos gemíferos portugueses

[Abstract] Anatomy and Classification of Portuguese Gemstone Deposits and their inclusion in Territorial Management Protocols - The concept of gemstone resources includes the consideration of aspects such as the genetic type of deposits, geographical location and geological characterization of the ores. Based on archeological evidences and assuming the geological potentiality it is possible to consider the existence of resources base with gem quality, in Portugal. The main deposits are related to residual granite systems. In order to ensure a sustainable use, economical or patrimonial, it is necessary to classify these occurrences in a context of land management. This paper presents the typology of the most interesting occurrences considering its economical and patrimonial potentiality

Desempenho e variabilidade genética de linhagens de tilápia Tailandesa e Red koina cultivadas em água salobra.

O experimento testou duas linhagens de tilápia: Tailandesa e Red koina. O objetivo foi avaliar o desempenho das linhagens cultivadas em água salobra e realizar análise da variabilidade genética das mesmas. Os peixes, machos revertidos sexualmente, com peso inicial de médio de 87,95 ± 22 g da Red Koina e 96,20 ± 25 g da Tailandesa, foram colocados em tanques-rede de 4 m3 de volume útil, em densidade de três peixes.m-3. Os tanques-rede estavam instalados em um viveiro revestido de geomembrana de PVC. Os peixes foram alimentados com ração comercial, na proporção de 5% da biomassa total estimada dos tanques. Os parâmetros avaliados foram: ganho em peso total, peso final, ganho em peso médio diário, taxa de conversão alimentar, consumo de ração e sobrevivência. O delineamento experimental foi totalmente ao acaso com dois tratamentos e três repetições. Após o experimento, os dados de desempenho zootécnico foram submetidos à ANOVA e análise de comparação de médias pelo PROC GLM, SAS. Resultados de desempenho comprovaram que a linhagem Tailandesa obteve desempenho superior ao da Red Koina. Resultados da análise de variabilidade genética indicaram que a variabilidade genética do estoque está preservada.bitstream/item/53773/1/BPD84.pd