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Time series forecasting : advances on Theta method
(Universidade Federal de São Carlos, 2016-05-13) Fiorucci, José Augusto; Louzada Neto, Francisco; https://lattes.cnpq.br/0994050156415890; https://lattes.cnpq.br/1473219810472634
Accurate and robust forecasting methods for univariate time series are critical as the historical data can be used in the strategic planning of such future operations as buying and selling to ensure product inventory and meet market demands. In this context, several competitions for time series forecasting have been organized, with the M3-Competition as the largest. As the winner of M3-Competition, the Theta method has attracted attention from researchers for its predictive performance and simplicity. The Theta method is a combination of other methods, which proposes the decomposition of the deseasonalized time series into two other time series called "theta lines". The first completely removes the curvatures of the data, thus accurately estimating the long-term trend. The second doubles the curvatures to better approximate short-term behavior. Several issues have been raised about the Theta method, even by its originators. They include the number of theta lines, their parameters, weights to combine them, and construction of prediction intervals, among others. This doctorate thesis resolves part of these issues. We derive optimal weights for combine the theta lines, this result is used to derive statistical models which generalizes /approximate the standard Theta method. The statistical methodology is considering for parameter estimation and for compute the prediction intervals. The optimal weights are also used to propose new methods that hold two or more theta lines. Part of proposed methodology is implemented in a package for R-programming language. In an empirical investigation using the M3-Competition data set with more than 3000 time series, the proposed methods/models demonstrated significant accuracy. The study’s primary approach, the Dynamic Optimised Theta Model, outperformed all benchmarks methods, constituting, in all likelihood, the highest-performing method for this data set available in the literature.
Indicadores do patenteamento de materiais armazenadores de hidrogênio voltados para o monitoramento tecnológico
(Universidade Federal de São Carlos, 2016-05-13) Oviedo Díaz, Sergio Manuel; Ishikawa, Tomaz Toshimi; https://lattes.cnpq.br/5726055117451807; https://lattes.cnpq.br/4425641529097589
Hydrogen is considered the energy carrier of the future, due to its high energy content and the possibility of its sustainable production. However, its broader implementation depends on overcoming of several technological challenges, which includes the development of safe and effective storage solutions. In the recent decades, different hydrogen storage materials (HSM) have been investigated for hydrogen storage in the solid state, such as simple hydrides, borohydrides, metalorganic frameworks (MOFs), alanates, intermetallic alloys, ammonia borane, and carbon-based compounds. Technological advances in HSM can be monitored from the patent document analysis applying bibliometrics coupled with text mining. In this study, the stage of the technology life cycle was evaluated, as well as the most prominent HSM and the role of different countries on this subject. Patent data were recovered from the Derwent Innovations Index database (DII), processed in bibliometric software VantagePoint® and used for the preparation of technical indicators. Patents in HSM decreased after 2007, except in China. The territories with more expressive patenting activity were the US, Japan, China and the European Union. Simple hydrides and borohydrides were the main classes for triadic patents in the US and EU, while Japan had a high participation in solid solution alloys. Despite its high number of patent applications, China has no triadic patents on HSM, raising doubts about the technological value of its domestic patents. The life-cycle assessment seems to show that the current stage is between the first prototype experiments in the market and a more spread use of the technologies; however, continued monitoring on the subject is necessary for a more accurate analysis.
Parâmetros agronômicos e bromatológicos de variedades de milho grão e silagem em sistema orgânico
(Universidade Federal de São Carlos, 2016-05-13) Giunti, Otavio Duarte; Silva, Ariana Vieira; https://lattes.cnpq.br/2062153447396275; Fontanetti, Anastácia; https://lattes.cnpq.br/3598362104615834; https://lattes.cnpq.br/1780752150400624
Maize is one of the most cultivated cereal in the world for its wide range of use in food, feed and industrial use. The production of grain and maize silage in organic system is essencial for the production of organic meat, milk and eggs, because this cereal makes up most of the rations and roughages used in a animal feed The objective was to evaluate the agronomic performance and bromatological parameters of silage of five commercial varieties (AL Avaré, AL Bandeirante, Cativerde 02, AL Piratininga and UFVM 200 - Soberano) and two maize landraces (Santa Rita 1 and Santa Rita 2), in two locations with climatic conditions and different altitudes (Araras / SP, 665 m altitude and Muzambinho / MG, 1100 m altitude) in organic production system. The experiment was carried out in a randomized block design in a 2x7 factorial with four replications. For evaluating the agronomic performance, was measured stalk diameter, plants height, insertion height of the upper ear, leaf number above the upper ear, Falker index of total chlorophyll, leaf nitrogen content, number of rows per ear, number of grain by row and grains per ear, lodging, final stand, 1000 grain weight and productivity. For the evaluation of bromatological parameters of silages was evaluated the productivity of green (GM) and dry matter (DM) and percentage of total dry matter (TDM), acid detergent fiber (ADF), neutral detergent fiber (NDF), crude protein (CP), mineral matter (MM), ether extract (EE), total carbohydrates (CHOT), and non-fiber carbohydrates (NFC) in silage. By results obtained, it was concluded that the agronomic performance of corn grain and the production of green and dry matter silages were influenced by environmental conditions, especially temperature and solar radiation, with better results in Muzambinho. But the environmental conditions not affected the bromatological parameters of silages, which were suitable for all varieties, in both locations. Under the experimental conditions, the landraces showed agronomic performance and bromatological parameters of silage similar to that of commercial varieties in two locations evaluated, indicating that they can be used in commercial crops under organic management.