268 research outputs found
Disaggregation process for dynamic multidimensional heat flux in building simulation
Heat transfer across envelopes (façade, roof, glazed areas) represents a big share of the energy flow within the heat balance of buildings. This paper focuses on areas of the envelope where multi-dimensional heat transfer occurs. These areas are commonly defined as thermal bridges, due to a localized reduction of thermal resistance of constructions in these places. This paper reviews common standardized methods to assess heat transfer in buildings, under various modelling assumptions: one-dimensional, multi-dimensional, steady state and dynamic. Within presently developed modelling and assessment methods, a need for improvement has been identified over existing methods for the thermal assessment of multi-dimensional heat transfer under dynamic conditions. A phasorial approach to differential heat transfer in thermal bridges has been developed, which serves as the dynamic extension of steady-state thermal bridge coefficients. This formulation is applied to the junction of a masonry wall with a concrete slab
On mixed radial Moore graphs of diameter 3
Radial Moore graphs and digraphs are extremal graphs related to the Moore
ones where the distance-preserving spanning tree is preserved for some
vertices. This leads to classify them according to their proximity to being a
Moore graph or digraph. In this paper we deal with mixed radial Moore graphs,
where the mixed setting allows edges and arcs as different elements. An
exhaustive computer search shows the top ranked graphs for an specific set of
parameters. Moreover, we study the problem of their existence by providing two
infinite families for different values of the degrees and diameter . One of
these families turns out to be optimal
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