7,215 research outputs found
Parameterized Complexity of Equitable Coloring
A graph on vertices is equitably -colorable if it is -colorable and
every color is used either or times.
Such a problem appears to be considerably harder than vertex coloring, being
even for cographs and interval graphs.
In this work, we prove that it is for block
graphs and for disjoint union of split graphs when parameterized by the number
of colors; and for -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 when
parameterized by the treewidth of the complement graph
Tourism planning informatization
The Tourism activity, due to its own characteristics, causes high environmental impact and its development should be influenced by the environmental characteristics of each region.
The Information Systems, mainly those which represent the geographical information, will permit the development of a design, allowing the Decision-Maker the consult, the management and the presentation of decision schemes based on the defined measures of the Tourism Planning of a region. As the information associated with this design should be real and update, the Internet should be used as a means of access to the information of the region.
The design presents the schemes associated to each decision, offering competitive advantages to the Decision-Makers involved in the decision process, since it is possible to evaluate, foresee and control the future environmental impacts of Tourism
GIS on tourism planning: preventing the impacts caused by the developing tourism activity in a specific site
The environment is one of the greatest concerns of humankind. Nowadays, the activities which improve or destroy it must be assessed and controlled by efficient means which should permit the control of environmental impact caused by the development of these activities. This document presents an information system implementation, as a Decision Support system, allowing the Decision Maker to evaluate, foresee and control the future environmental impact of Tourism through consultation, the management and the presentation of decision schemes based on defined measures of a regional tourism planning
Symbolic Computation of Variational Symmetries in Optimal Control
We use a computer algebra system to compute, in an efficient way, optimal
control variational symmetries up to a gauge term. The symmetries are then used
to obtain families of Noether's first integrals, possibly in the presence of
nonconservative external forces. As an application, we obtain eight independent
first integrals for the sub-Riemannian nilpotent problem (2,3,5,8).Comment: Presented at the 4th Junior European Meeting on "Control and
Optimization", Bialystok Technical University, Bialystok, Poland, 11-14
September 2005. Accepted (24-Feb-2006) to Control & Cybernetic
Divergência genética entre acessos de cupuaçuzeiro, procedentes de plantios comerciais de Tomé-Açu - Pará.
Tuning in magnetic modes in Tb(Co_{x}Ni_{1-x})_{2}B_{2}C: from longitudinal spin-density waves to simple ferromagnetism
Neutron diffraction and thermodynamics techniques were used to probe the
evolution of the magnetic properties of Tb(Co_{x}Ni_{1-x})_{2}B_{2}C. A
succession of magnetic modes was observed as x is varied: the longitudinal
modulated k=(0.55,0,0) state at x=0 is transformed into a collinear
k=([nicefrac]\nicefrac{1}{2},0,[nicefrac]\nicefrac{1}{2})
antiferromagnetic state at x= 0.2, 0.4; then into a transverse c-axis modulated
k=(0,0,[nicefrac]\nicefrac{1}{3}) mode at x= 0.6, and finally
into a simple ferromagnetic structure at x= 0.8 and 1. Concomitantly, the
low-temperature orthorhombic distortion of the tetragonal unit cell at x=0 is
reduced smoothly such that for x >= 0.4 only a tetragonal unit cell is
manifested. Though predicted theoretically earlier, this is the first
observation of the k=(0,0,[nicefrac]\nicefrac{1}{3}) mode in
borocarbides; our findings of a succession of magnetic modes upon increasing x
also find support from a recently proposed theoretical model. The implication
of these findings and their interpretation on the magnetic structure of the
RM_{2}B_{2}C series are also discussed
Avaliação socioeconômica de sistemas produtivos de banana na região ribeirinha do Juruá, Acre.
Introdução; Metodologia; Abragência dos sistemas de produção; Identificação e caracterização dos sistemas de produção; Avaliação sócioeconômica; Orçamentos; Mão de obra familiar; despesas com ferramenta, equipamentos e instalações; Preços de materiais e serviços para os orçamentos; Indicadores socioeconômicos; Resultados; Abreviações utilizadas; Sistema de produção tradicional de banana na região do Vale do Rio Juruá, Acre; Sistema de produção melhorado de banana na região do Vale do Rio Juruá, Acre; Análise comparativa entre os sistemas de produção tradicional e melhorado; Consideraçãoes finaisbitstream/item/144205/1/7309.pd
Método de Seleção de bactérias antagonistas a Sclerotinia sclerotiorum.
O objetivo deste trabalho foi obter e avaliar o efeito de bactérias isoladas de escleródios como agentes antagônicos no crescimento micelial de S. sclerotiorum
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