Mixed models for short-run forecasting of electricity prices: Application for the Spanish market

Short-run forecasting of electricity prices has become necessary for power generation unit schedule, since it is the basis of every profit maximization strategy. In this article a new and very easy method to compute accurate forecasts for electricity prices using mixed models is proposed. The main idea is to develop an efficient tool for one-step-ahead forecasting in the future, combining several prediction methods for which forecasting performance has been checked and compared for a span of several years. Also as a novelty, the 24 hourly time series has been modelled separately, instead of the complete time series of the prices. This allows one to take advantage of the homogeneity of these 24 time series. The purpose of this paper is to select the model that leads to smaller prediction errors and to obtain the appropriate length of time to use for forecasting. These results have been obtained by means of a computational experiment. A mixed model which combines the advantages of the two new models discussed is proposed. Some numerical results for the Spanish market are shown, but this new methodology can be applied to other electricity markets as well

Leakage of nitrous oxide emissions within the Spanish agro-food system in 1961-2009

Abstract In this paper we examine the trends of nitrous oxide (N2O) emissions of the Spanish agricultural sector related to national production and consumption in the 1961?2009 period.The comparison between production- and consumption-based emissions at the national level provides a complete overview of the actual impact resulting from the dietary choices of a given country and allows the evaluation of potential emission leakages. On average, 1.5 % of the new reactive nitrogen that enters Spain every year is emitted as N2O. Production- and consumption-based emissions have both significantly increased in the period studied and nowadays consumption-based emissions are 45 % higher than production-based emissions. A large proportion of the net N2O emissions associated with imported agricultural godos comes from countries that are not committers for the United Nations Framework Convention on Climate Change Kyoto Protocol Annex I. An increase in feed consumption is the main driver of the changes observed, leading to a arkable emission leakage in the Spanish agricultural sector. The complementary approach used here is essential to achieve an effective mitigation of Spanish greenhouse gas emissions.

Occurrence of moulds associated with ovine raw milk and cheeses of the Spanish region of Castilla La Mancha

The distribution of mould species was examined at several points of the processing chain in a Manchego cheese plant and associated dairy farms. Geotrichum and Fusarium were the most frequent genera isolated in milk samples as well as in 1-month ripened cheeses, evidencing a direct transfer from raw milk. Conversely, the mycobiota of long-ripened cheeses consisted mainly of Penicillium species, which gained entry to the cheese through the air of ripening rooms. This study contributes to the understanding of the dynamics of fungal populations in semihard and hard cheeses, highlighting that airborne transfer from the stables could have a direct impact on their quality.

Pre-investigation of water electrolysis for flexible energy storage at large scales: the case of the Spanish power system

This report analyzes the basis of hydrogen and power integration strategies, by using water electrolysis processes as a means of flexible energy storage at large scales.

Can seed production and restricted dispersal limit recruitment in Pinus pinaster Aiton from the Spanish Northern Plateau?

Natural regeneration faces increasing difficulties in dry forests from the Mediterranean basin, including for normally well-regenerating species such as maritime pine (Pinus pinaster Aiton). In this paper, we studied female fertility, seed dispersal and spread rates in P. pinaster from the Spanish Northern Plateau, where natural regeneration failure is a main concern for forest managers. For this purpose we periodically collected data from seed traps and trees located at two core locations across several years. We found significant variation in interannual cone production, with the best seed trees being the same across years. In addition, we found highly skewed distributions of female reproductive effort and large fertility differences across stands located few kilometres away. Annual seed dispersal kernels fitted lognormal or 2Dt models depending on the stand analysed, with median dispersal distances between 14 and 25 m. Kernels fitted for maximum dispersal periods showed an outstanding intraseasonal variation of median dispersal distances, from 10 to 54 m, in association to variable patterns of rainfall and maximum wind speed. The amount of seed produced appeared to be enough to guarantee the natural regeneration of the stands during the typical 20-year regeneration period. Colonisation simulations concluded that Mediterranean maritime pine has a notable dispersion capacity, which is strongly influenced by levels of fecundity and, especially, by the number and frequency of long-distance dispersal events. The latter play a key role in tree dispersion processes through enlarging the occupied area and fostering the invasion of abandoned crop land.

Runup variability due to time dependence and stochasticity in the beach profiles: two extreme cases of the Spanish coast

Equations for extreme runup worked out from several experimental studies are compared. Infragraviatory oscillations dominate the swash in a dissipative state but not in intermediate - reflective states. Therefore two kinds of equation depending on either significant wave height, H-0, or the Iribarren number, xi(0), should be used. Through a sand bed physical model with a uniform sand bed slope, equations are proposed for both beach states, and results are compared with precedent field and physical model experiments. Once the equations are chosen, the time-longshore variability in a medium - long term time scale of the foreshore slope is evaluated in two extreme cases relating to the Spanish coast. The Salinas beach on the North coast (Bay of Biscay) displayed a permanent dissipative beach state with small variations in the beach foreshore slope both along the shore and in time, so foreshore slope deviations in a medium-long term period were irrelevant and extreme runup is predicted with the wave height worked out from the design return period. Peniscola beach on the East coast (Mediterranean sea) displayed an intermediate state. If only time variations are analysed, variations in determining extreme runup are irrelevant. In contrast, significant differences were found when the longshore variations were studied in this Mediterranean beach.

Letters concerning the Spanish nation : [Texto impreso] writen at Madrid during the years 1760 and 1761

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Unravelling past flash flood activity in a forested mountain catchment of the Spanish Central System

Flash floods represent one of the most common natural hazards in mountain catchments, and are frequent in Mediterranean environments. As a result of the widespread lack of reliable data on past events, the understanding of their spatio-temporal occurrence and their climatic triggers remains rather limited. Here, we present a dendrogeomorphic reconstruction of past flash flood activity in the Arroyo de los Puentes stream (Sierra de Guadarrama, Spanish Central System). We analyze a total of 287 increment cores from 178 disturbed Scots pine trees (Pinus sylvestris L.) which yielded indications on 212 growth disturbances related to past flash flood impact. In combination with local archives, meteorological data, annual forest management records and highly-resolved terrestrial data (i.e., LiDAR data and aerial imagery), the dendrogeomorphic time series allowed dating 25 flash floods over the last three centuries, with a major event leaving an intense geomorphic footprint throughout the catchment in 1936. The analysis of meteorological records suggests that the rainfall thresholds of flash floods vary with the seasonality of events. Dated flash floods in the 20th century were primarily related with synoptic troughs owing to the arrival of air masses from north and west on the Iberian Peninsula during negative indices of the North Atlantic Oscillation. The results of this study contribute considerably to a better understanding of hazards related with hydrogeomorphic processes in central Spain in general and in the Sierra de Guadarrama National Park in particular.

Water use efficiency and water productivity in the Spanish irrigation district ¿Río Adaja?

A study of the assessment of the irrigation water use has been carried out in the Spanish irrigation District “Río Adaja” that has analyzed the water use efficiency and the water productivity indicators for the main crops for three years: 2010-2011, 2011-2012 and 2012-2013. A soil water balance model was applied taking into ccount climatic data for the nearby weather station and soil properties. Crop water requirements were calculated by the FAO Penman- Monteith with the application of the dual crop coefficient and by considering the readily vailable soil water content (RAW) concept. Likewise, productivity was measured by the indexes: annual relative irrigation supply (ARIS), annual relative water supply (ARWS), relative rainfall supply (RRS), the water productivity (WP), the evapotranspiration water productivity (ETWP), and the irrigation water productivity (IWP. The results show that in most crops deficit irrigation was applied (ARIS<1) in the first two years however, the IWP improved. This was higher in 2010-2011 which corresponded to the highest effective precipitation Pe. In general, the IWP (€.m-3) varied amongcrops but crops such as: onion (4.14, 1.98 and 2.77 respectively for the three years), potato (2.79, 1.69 and 1.62 respectively for the three years), carrot (1.37, 1.70 and 1.80 respectively for the three years) and barley (1.21, 1.16 and 0.68 respectively for the three years) showed the higher values. Thus, it is highlighted the y could be included into the cropping pattern which would maximize the famer’s gross income in the irrigation district.

A Valuation of SAREB, the Spanish “Bad Bank”, Upside Using the Real Options Methodology

This paper develops a model to analyze the upside potential of profitability of the SAREB (“Asset Management Company for Assets Arising from Bank Restructuring”), the Spanish “Bad Bank”. The model is based in the Real Options methodology, that is especially adequate due to the convergence of two elements, (i) depreciated assets with a high upside potential, and (ii) a highly volatile market as it has shown to be the real estate Spanish market. Our results suggest that the SAREB has a higher than expected profitability potentialthat would be dedicated to increase the return to its shareholders, mainly private banks. Consequently we also show that after the financial crisis are emerging two types of banks in Spain, in one hand the losers who are transferring their real estate assets at a deep discount, and in the other hand the winners, capturing the upside potential of those assets as shareholders of SAREB, and consequently consolidating their strength in the Spanish Real Estate Industry. It is worth to mention that Governments should make an effort in properly redistribute the wealth generated by the real Estate industry.

Return of Equity Issues in the Spanish Stock Market from the Investor’s Perspective, during the 1997-2012 Period

Is it profitable for an investor, from a risk-return perspective, to acquire a stake in a quoted company when a capital increase is announced? This paper analyses the return obtained from the investment in equity issues with cash contribution and pre-emptive rights, aimed at funding corporate activities: acquisitions, investments in new facilities and/or strengthening the balance sheet of the companies undertaking the equity issue. During the 16 years covered by the study, the results show a negative average excess risk-adjusted return of almost 5%, from the moment that the equity offer is announced until the completion of the preferential subscription period. To obtain this excess return, the difference between the nominal Internal Rate of Return (IRR) and the expected return, using the CAPM, is computed for each equity issue. The intention behind this method is to eliminate the effects of time and any other possible effect on the stock price during the period of the analysis.The results from this article are consistent with the Pecking Order theory for the Spanish Stock Market also six months after the preferential subscription period. However, there is a positive return after three months.

Differences brick facade design to horizontal loads between the Spanish and European standards

Brick facades are a construction type, strongly linked to local construction characteristics and methods. In Spain, particularly in Castilla, the facades have been built since the '80s with Castilian half foot (11.5 cm), resting on the edge of slabs. The design of these facades, to horizontal loads from wind, depending on the codes used, can lead to completely different valid solutions. Applying same loads, the facades studied with current European standard (Eurocode 6), have a maximum length of 7.1 m between supports, while the Spanish code, Technical Building Code - Structural Safety Masonry, (CTE SE-F), 8.4 m can be achieved. This represents an increase of flexural strength, depending on the calculation model used, which can reach until 8 times. This is due to the difference of the calculation method and the structural model in one and another standard, depending on if this facade is analyzed as a vertical or horizontal beam or by formation of a vertical or horizontal archh. This paper analyzes the constructive solution of the brick facades that results from applying Spanish or European standards and how it affects the model applied in the safety of the resulting facade.

Gender differences of the spanish adult population in barriers to active living

Proyecto I+D+i DEP19801: Gender differences of the spanish adult population in barriers to active living

Gender differences of the spanish adult population in cultural barriers to active living

Proyecto I+D+i DEP19801: Gender differences of the spanish adult population in cultural barriers to active living

Gender differences of the spanish adult population in barriers to active living

Social research on the needs, barriers and innovations in sport and physical activities to adult women in Spain