Forestry, geology and hydrological investigations from ERTS-1 imagery in two areas of Ecuador, South America

The author has identified the following significant results. In the Oriente area, well-drained forests containing commercially valuable hardwoods can be recognized confidently and delineated quickly on the ERTS imagery. In the tropical rainforest, ERTS can provide an abundance of inferential information about large scale geologic structures. ERTS imagery is better than normal aerial photography for recognizing linears. The imagery is particularly useful for updating maps of the distributary system of the Guagas River Basin and of any other river with a similarly rapid changing channel pattern

Diffusion and Relaxation Dynamics in Cluster Crystals

For a large class of fluids exhibiting ultrasoft bounded pair potentials, particles form crystals consisting of clusters located in the lattice sites, with a density-independent lattice constant. Here we present an investigation on the dynamic features of a representative example of this class. It is found that particles can diffuse between lattice sites, maintaining the lattice structure, through an activated hopping mechanism. This feature yields finite values for the diffusivity and full relaxation of density correlation functions. Simulations suggest the existence of a localization transition which is avoided by hopping, and a dynamic decoupling between self- and collective correlations.Comment: 4 pages, 7 figure

Explicit Soliton for the Laplacian Co-Flow on a Solvmanifold

We apply the general Ansatz in geometric flows on homogeneous spaces proposed by Jorge Lauret for the Laplacian co-flow of invariant $G_2$-structures on a Lie group, finding an explicit soliton on a particular almost Abelian $7$-manifold.Comment: Minor corrections, proof's Lemma 4.1 modified. To appear in the S\~ao Paulo Journal of mathematical scienc

Should energy labels for washing machines be expanded to include a durability rating?

Washing machines are a key household appliance that can be found in the majority of UK homes. Over 2.5 million are sold in the UK every year and account for one of the highest material and production impacts of householder products in the UK (WRAP, 2011). Energy efficiency ratings are provided as a method for consumers to make an informed purchasing decision and were brought in by EU legislation to reduce energy use and enable users to reduce running costs, as it is known that the greater environmental impact of a washing machine is during use. From 2014, all washing machines sold must be at a minimum A rated, with ratings increasing to A+++. However, under this current labelling system the embodied impacts and durability of the machines are ignored. Through semi-structured interviews with consumers, manufacturers and distributors, this paper explores different perceptions of longevity and expectations of performance and durability. The paper explores whether energy labels should be expanded to include durability information, as this could enable consumers to make a decision based not only on cost and energy efficiency but also on expected lifespan. Existing manufacturer’s guarantees may give an indication of the expected durability of the product and this is investigated to explore if there is a positive correlation. The findings will further discuss the potential impacts of providing durability information and how this could enable manufacturers and consumers to shift towards a low material and energy future

Improved routing strategies for Internet traffic delivery

We analyze different strategies aimed at optimizing routing policies in the Internet. We first show that for a simple deterministic algorithm the local properties of the network deeply influence the time needed for packet delivery between two arbitrarily chosen nodes. We next rely on a real Internet map at the autonomous system level and introduce a score function that allows us to examine different routing protocols and their efficiency in traffic handling and packet delivery. Our results suggest that actual mechanisms are not the most efficient and that they can be integrated in a more general, though not too complex, scheme.Comment: Final versio

Spectral changes in layered ff-electron systems induced by Kondo hole substitution in the boundary-layer

We investigate the effect of disorder on the dynamical spectrum of layered $f$-electron systems. With random dilution of $f$-sites in a single Kondo insulating layer, we explore the range and extent to which Kondo hole incoherence can penetrate into adjacent layers. We consider three cases of neighboring layers: band insulator, Kondo insulator and simple metal. The disorder-induced spectral weight transfer, used here for quantification of the proximity effect, decays algebraically with distance from the boundary layer. Further, we show that the spectral weight transfer is highly dependent on the frequency range considered as well as the presence of interactions in the clean adjacent layers. The changes in the low frequency spectrum are very similar when the adjacent layers are either metallic or Kondo insulating, and hence are independent of interactions. In stark contrast, a distinct picture emerges for the spectral weight transfers across large energy scales. The spectral weight transfer over all energy scales is much higher when the adjacent layers are non-interacting as compared to when they are strongly interacting Kondo insulators. Thus, over all scales, interactions screen the disorder effects significantly. We discuss the possibility of a crossover from non-Fermi liquid to Fermi liquid behavior upon increasing the ratio of clean to disordered layers in particle-hole asymmetric systems.Comment: 14 pages, 9 figure

Variable neighbourhood search for the minimum labelling Steiner tree problem

We present a study on heuristic solution approaches to the minimum labelling Steiner tree problem, an NP-hard graph problem related to the minimum labelling spanning tree problem. Given an undirected labelled connected graph, the aim is to find a spanning tree covering a given subset of nodes of the graph, whose edges have the smallest number of distinct labels. Such a model may be used to represent many real world problems in telecommunications and multimodal transportation networks. Several metaheuristics are proposed and evaluated. The approaches are compared to the widely adopted Pilot Method and it is shown that the Variable Neighbourhood Search that we propose is the most effective metaheuristic for the problem, obtaining high quality solutions in short computational running time