Study of growth-environment relationships and optimisation of management including climatic uncertainty of radiata pine stands in Galicia

Climate change is intended to impact forest dynamics significantly inthe following decades. To proactively adapt forest management to these expected alterations, new methodologies for handling the uncertain-ties regarding forest growth under varying environmental conditions become necessary. The purpose of this thesis was to forecast the impact of climate change on radiata pine plantations in the northwest of Spain in terms of productivity, profitability, and silvicultural treatments. In Study I, several statistical techniques were used for predicting thesite index (SI) of radiata pine stands using environmental predictors extracted from available raster maps. A non-linear technique, Multivariate Adaptive Regression Splines (MARS), was suggested as the best modelling alternative, explaining up to 52% of the SI variability. In Study II, the Support Vector Regression technique was used to predict SI and delimit the validity area of predictions based on the radial basis kernel. The resulting model had high predictive performance, provided robust predictions under varied climatic conditions, and included a relatively small number of predictors. Moreover, the model was able to identify areas where climatic conditions were very different from the observed and consequently regularised predictions for those areas. In Study III, silviculture under climate change was optimised for maximising the soil expectation value of a set of radiata pine plantations. The future forest productivity projections, produced by the model developed in Study II, forecasted an overall reduction in SI under climate change, mainly driven by increased temperatures and continentality. Consequently, the economic simulations forecasted a drop in profitability under climate change that was more intense for more pessimistic scenarios (RCP 6.0). However, the climatic projections were very varied over the set of used climate models, which led to a great dispersion in productivity and profitability predictions. From the perspective of silviculture, the most notable forecasted variation is the expected increase in optimum rotation lengths

Global properties of the spectrum of the Haldane-Shastry spin chain

We derive an exact expression for the partition function of the su(m) Haldane-Shastry spin chain, which we use to study the density of levels and the distribution of the spacing between consecutive levels. Our computations show that when the number of sites N is large enough the level density is Gaussian to a very high degree of approximation. More surprisingly, we also find that the nearest-neighbor spacing distribution is not Poissonian, so that this model departs from the typical behavior for an integrable system. We show that the cumulative spacing distribution of the model can be well approximated by a simple functional law involving only three parameters.Comment: RevTeX 4, 7 pages, 4 figures. To appear in Phys. Rev.

Delimiting the spatio-temporal uncertainty of climate-sensitive forest productivity projections using Support Vector Regression

As climate change makes many traditional empirical growth approaches not functional for forest dynamics modelling, new climate-sensitive models are needed. However, using these newly developed models for extrapolation, such as predicting forest productivity for new areas or future scenarios is still a difficult task. In this study, we proposed a method for delimiting the uncertainty of climate-sensitive extrapolations of forest productivity (site index, ) using the regularisation approach implicit in distance-based Support Vector Regression. As a case study, we predicted forest productivity with a dataset of 165 permanent research plots of radiata pine forests in Galicia (NW of Spain) as a function of bioclimatic variables from the Worldclim 2 raster datasets. The developed model was based on the radial basis kernel and, after calibrating it using cross-validation, produced adequate performance metrics, explaining up to 56% of the site index’ variability. Then, we predicted forest productivity for the Galician territory basing on climate raster maps for current conditions and six future scenarios (using different Global Climate Models) and evaluated the resulting maps by delimiting the surfaces with predictions strongly regressed to the mean. This analysis revealed that the extrapolations for unseen climatic conditions were extremely regularised, even for current climate, being 60–99% of the territory regressed to the observational site index mean. In other words, the validity area delimited for the fitted model was narrow in comparison with the prediction extent. These results imply that the climatic conditions in these areas/scenarios were too different from the training datastet for making reliable predictions, at least under the optimum model setup defined by cross-validation. However, when we reduced the parameter, responsible for controlling distance-based regularisation, we observed a noticeable increase in validity area of the model, together with a drop in performance. This fact revealed the existence of a trade–off between highly specific models, with high performance and a small applicability area, and more generalisable models, with a broad validity area but lower performance. We concluded that the tested methodology could be a useful starting point for assessing the spatio-temporal uncertainty of forest productivity predictions in the futureThe work of the first author and main researcher of this study has been partially funded by the Spanish Ministry of Science, Innovation and Universities (DI-16–08971) and by the forest management consultancy company CERNA Ingeniería y Asesoría Medioambiental S.L. Plot data collection was carried out in the frame of two research projects (AGL2008-02259 and AGL2001-3871-C02-01) funded by the Spanish Ministry of Science and Innovation, the Spanish Interdepartmental Commission of Science and Technology and the European Commission (European Regional Development Fund)S

Ecuaciones de Bargmann-Wigner : simetrías de Bispinors y formulación hamiltoniana

Tesis Univ. Complutense de Madrid, 1979.Fac. de Ciencias FísicasTRUEProQuestpu

Nave de almacenaje y distribución de alimentos y medicamentos para animales

[Resumen] En el presente proyecto se desarrolla el diseño de una nave industrial dedicada al almacenaje de alimentos y medicamentos para animales. Se realizan los cálculos de la estructura metálica y su cimentación, así como los cálculos de las uniones que corresponden a dicha estructura. Además se diseña la urbanización de la parcela en la que se realizará la construcción. Con el fin de justificar y definir correctamente lo proyectado, así como los términos legales, urbanísticos y de seguridad, el proyecto está compuesto por los siguientes documentos: memoria, anjeos a la memoria, planos, pliego de condiciones, estudio de seguridad y salud y por último, presupuesto.[Resumo] Neste proxecto desenvólvese o deseño dunha nave industrial dedicada ao almacenamento de alimentos e medicamentos para animais. Realízanse os cálculos da estrutura metálica e a súa cimentación, así como os cálculos das unións que corresponden a dita estrutura. Ademais, proxéctase a urbanización da parcela na que se levará a cabo a construción. Co fin de xustificar e definir correctamente o que se proxecta, así como os termos legais, urbanísticos e de seguridade, o proxecto está composto polos seguintes documentos: memoria, anexos á memoria, planos, especificacións, estudo de seguridade e saúde, e finalmente presuposto.[Abstract] This project develops the design of an industrial warehouse dedicated to the storage of food and medicines for animals. The calculations of the metal structure and its foundations are carried out, as well as the calculations of the joints corresponding to said structure. In addition, the urbanization of the plot in which the construction will be carried out is designed. In order to justify and correctly define the project, as well as the legal, urban and security terms, the project is composed of the following documents: memory, memories, plans, specifications, health and safety study and finally, budget.Traballo fin de grao (UDC.EPS). Enxeñaría mecánica. Curso 2020/202

Buque portacontenedores de 20000 TEUS adaptado a ruta Asia-Europa

Resumen: La finalidad del presente Trabajo Fin de Grado es el dimensionamiento y definición de un buque portacontenedores, cumpliendo con la RPA establecida. Una de las principales características es que es un buque de carga normalizada que ha de transportar 20 000 TEUS, lo cual afecta a las dimensiones del mismo. Este portacontenedores será diseñado para dar servicio a la ruta Asia –Norte de Europa, por lo que ha de tener una autonomía que le permita realizar un trayecto de unas 20000 millas.Resumo: A finalidade do presente Traballo de Fin de Grao é o dimensionamento e definición dun buque portacontenedores, cumprindo co establecido na RPA. Unha das principais características é que é un buque de carga normalizada que transporta 20000 TEUS, o cal afecta as dimensións do mesmo. Este portacontenedores deseñarase para dar servizo a ruta Asia–Norte de Europa, polo que terá unha autonomía que permita realizar o traxecto dunhas 20000 millas.Abstract: The purpose of this Final Degree Project is the dimensioning and definition of a container ship, complying with the established RPA. One of themain characteristics is that it is a standardized cargo ship and that it has to transport 20,000 TEUS, which affects its dimensions. This container ship will be designed to serve the Asia -North Europe route, so it must have an autonomy that allows it tocover a journey of about 20,000 miles.Traballo Fin de Grao (UDC. EPS). Ingeniería Naval y Oceánica (Curso 2020/2021

Integrating descriptions of knowledge management learning activities into large ontological structures: A case study

Ontologies have been recognized as a fundamental infrastructure for advanced approaches to Knowledge Management (KM) automation, and the conceptual foundations for them have been discussed in some previous reports. Nonetheless, such conceptual structures should be properly integrated into existing ontological bases, for the practical purpose of providing the required support for the development of intelligent applications. Such applications should ideally integrate KM concepts into a framework of commonsense knowledge with clear computational semantics. In this paper, such an integration work is illustrated through a concrete case study, using the large OpenCyc knowledge base. Concretely, the main elements of the Holsapple & Joshi KM ontology and some existing work on e-learning ontologies are explicitly linked to OpenCyc definitions, providing a framework for the development of functionalities that use the built-in reasoning services of OpenCyc in KM ctivities. The integration can be used as the point of departure for the engineering of KM-oriented systems that account for a shared understanding of the discipline and rely on public semantics provided by one of the largest open knowledge bases available

Gender differences in e-learning satisfaction

In line with recent research, the question this paper raises is whether or not gender differences also exist in e-learning. This study is based on a sample of 1,185 students who are doing on-line courses at the Universidad de Granada in Spain. The main conclusion is that female students are more satisfied than male students with the e-learning subjects that make up the sample. Furthermore, we find that female students assign more importance to the planning of learning, as well as to being able to contact the teacher in various ways.: Gender Studies; Evaluation Methodologies

Effect of mold temperature on the impact behavior and morphology of injection molded foams based on polypropylene polyethylene–octene copolymer blends

Producción CientíficaIn this work, an isotactic polypropylene (PP) and a polyethylene–octene copolymer (POE) have been blended and injection-molded, obtaining solids and foamed samples with a relative density of 0.76. Different mold temperature and injection temperature were used. The Izod impact strength was measured. For solids, higher mold temperature increased the impact resistance, whereas in foams, the opposite trend was observed. In order to understand the reasons of this behavior, the morphology of the elastomeric phase, the crystalline morphology and the cellular structure have been studied. The presence of the elastomer near the skin in the case of high mold temperature can explain the improvement produced with a high mold temperature in solids. For foams, aspects as the elastomer coarsening in the core of the sample or the presence of a thicker solid skin are the critical parameters that justify the improved behavior of the materials produced with a lower mold temperature.Ministerio de Economía, Industria y Competitividad (grant DI-15-07952