Chromatic roots and limits of dense graphs

In this short note we observe that recent results of Abert and Hubai and of Csikvari and Frenkel about Benjamini--Schramm continuity of the holomorphic moments of the roots of the chromatic polynomial extend to the theory of dense graph sequences. We offer a number of problems and conjectures motivated by this observation.Comment: 9 page

Micro-Hotplates for Thermal Characterisation of Structural Materials of Mems

Accurate knowledge of mechanical and thermal properties of structural materials used in MEMS is essential for optimum geometric and functional design. The extraction of precise physical properties is rather complicated due to the size effects, the complexity of the structures and the variations of formation processes. This work is intended to determine the thermal properties of silicon-nitride and diamond layers applied in thermal sensor structures by analyzing thermal responses of a multilayer micro-heater structure.Comment: Submitted on behalf of TIMA Editions (http://irevues.inist.fr/tima-editions

EIP-AGRI Focus Group Agroforestry MINIPAPER 3::Tools for Optimal Design and Management

Agroforestry (AF) so far is not a well-known and widespread way of agricultural production in Europe, with barriers such as legal issues, unpredictable financial outcomes, etc playing an important role here. But even for those who would opt to implement AF, it’s generally not easy to find or to have access to guidelines and tools for the design and management of such a system.Therefore in the further promotion of effective agroforestry systems (AFS) in Europe, an increased awareness of the existence of and the development of new design and management tools for farmers would be an important step forward.A well-organized system of tools could represent a kind of „guide” - accompanied with access to relevant information (databases, sources of structured and practical knowledge), and further tools (business plan, financial analysis, etc) -, that leads the farmers’ way through the process of decision-making and to the installation on the field

EIP-AGRI Focus Group Agroforestry MINIPAPER 7: Financial Impact of Agroforestry

There is a balance to be achieved by agroforestry economists when they are asked to both “promote” agroforestry and determine the profitability of agroforestry. A conclusion of Graves et al. (2007) was that silvoarable agroforestry was likely to be of greatest interest where the profitability of the tree system was similar to that of the arable system; otherwise the owner would be best advised to focus on either the more profitable arable or forestry system. However many of the practical examples of where agroforestry seem to be implemented on a conventional arable or livestock farm, is to make the main enterprise more sustainable. An example of this is “woodlandeggs” e.g. in he UK. Similarly, farmer Stephen Briggs has planted a silvoarable system in order to reduce soil erosion on his peatland arable farm in Eastern England.Some agroforestry promotion is focused on the improvement of grants. However in the absence of progress, some farmers are particularly adept at finding agroforestry combinations that do not invalidate single-farm or basic payments. For example planting agricultural crops such as apple trees allow the farmer to retain his land as “agricultural land” whilst increasing tree cover. In a similar way, tree strips can be designated as “wildflower strips” to benefit from agri-environment payments. It can be argued that the key component of any successful agroforestry system is the farmer (Burgess, 2017).There remains a dearth of information for farmers about the value of wood. An efficient wood market would benefit from greater transparency in timber and wood prices for small producers.There remains a need to firstly account for the additional complexity and administrative costs associated with agroforestry in financial analyses. In addition, on-going maintenance costs and other non-financial on-going commitments are unknown, unclear and hence are a barrier at planting. Secondly, in view ofthe substantial wider societal benefits of agroforestry, ways should be sought to minimise the unnecessary administrative burden. It is clear than the current system of “complex rules” has tended to lead to a more “simplified landscape”. Is it possible to deliver a system of “simple rules” that creates a more “complex and diverse landscape”?This analysis focuses solely on the financial analysis of the marketable components of the system. A wider economic analysis would consider wider societal benefits and the impacts of grants and subsidies

Statistical matching theory

Non UBCUnreviewedAuthor affiliation: MITPostdoctora

Homomorphisms of Trees into a Path

Let hom(G,H) denote the number of homomorphisms from a graph G to a graph H. In this paper we study the number of homomorphisms of trees into a path, and prove that hom(P[subscript m],P[subscript n]) ≤ hom(T[subscript m],P[subscript n]) ≤ hom(S[subscript m],P[subscript n]), where T[subscript m] is any tree on m vertices, and P[subscript m] and S[subscript m] denote the path and star on m vertices, respectively. This completes the study of extremal problems concerning the number of homomorphisms between trees started in the paper Graph Homomorphisms Between Trees [Electron. J. Combin., 21 (2014), 4.9] written by the authors of the current paper