326 research outputs found

    Intertemporal Choice of Fuzzy Soft Sets

    Get PDF
    This paper first merges two noteworthy aspects of choice. On the one hand, soft sets and fuzzy soft sets are popular models that have been largely applied to decision making problems, such as real estate valuation, medical diagnosis (glaucoma, prostate cancer, etc.), data mining, or international trade. They provide crisp or fuzzy parameterized descriptions of the universe of alternatives. On the other hand, in many decisions, costs and benefits occur at different points in time. This brings about intertemporal choices, which may involve an indefinitely large number of periods. However, the literature does not provide a model, let alone a solution, to the intertemporal problem when the alternatives are described by (fuzzy) parameterizations. In this paper, we propose a novel soft set inspired model that applies to the intertemporal framework, hence it fills an important gap in the development of fuzzy soft set theory. An algorithm allows the selection of the optimal option in intertemporal choice problems with an infinite time horizon. We illustrate its application with a numerical example involving alternative portfolios of projects that a public administration may undertake. This allows us to establish a pioneering intertemporal model of choice in the framework of extended fuzzy set theorie

    Torsion injective covers and resolvents

    Get PDF

    Determination of volumetric variations and coastal changes due to historical volcanic eruptions using historical maps and remote-sensing at Deception Island (West-Antarctica)

    Get PDF
    Deception Island is an active volcano in the South Shetland Islands (Antarctic). Its eruptions have been recorded since 1842, the last episode occurring between 1967 and 1970. This study quantifies the geomorphological changes which have taken place as a result of historical volcanic activity on the island. The linear and volumetric results obtained for the Telefon Bay and Craters of 1970s where the Surtseyan eruption took place in 1967 are presented in detail.Ministerio de Educación y Ciencia CGL2005-07589-C03- 01/ANTMinisterio de Educación y Ciencia CGL2004-21547-EMinisterio de Educación y Ciencia CGL2007-28768-E/ANTMinisterio de Educación y Ciencia CTM2009-0725

    Regional Positioning Services as economic and construction activity indicators: the case study of Andalusian Positioning Network (Southern Spain)

    Get PDF
    The Andalusian Positioning Network (RAP) is a regional GNSS permanent network in southern Spain that offers two public services for precise positioning: real-time (RAP-IP) and post processing (RAP-FTP). The most of registered users are linked to the construction sector, so the collapse of the housing bubble and the Spanish economic crisis influenced the use of RAP services from 2008. The behavior of these services has differed somewhat, although analysis for the years 2008 to 2013 reveals a general decline. Since 2009 the RAP-FTP service demand fell by 50%, but the RAP-IP service was stable until October 2011, when it began a steep decline in December 2012. Analyzing the temporal demand and the geospatial connections of RAP-IP with economic impact indicators, we found a high linear correlation between this service and jobs in the construction sector (0.98) and permit building (0.96). The real time and associated geoinformation are its main advantages

    Gas exchange and water relations of young apricot plants under drought conditions

    Get PDF
    Potted 1.5-year-old apricot plants (Prunus armeniaca L.), growing under polycarbonate glasshouse conditions with a cooling system, were subjected to two successive water stress/recovery periods until pre-dawn leaf water potential (Ypd) reached values between -2.0 and -2.5 MPa, during summer 1996. Control plants were irrigated daily to maintain the soil matric potential at c. -20 kPa. Water stress limited plant growth and induced a significant reduction in leaf area, caused by mature leaf abscission. The parallel behaviour of leaf turgor potential and epinasty in stressed plants indicated that these movements are turgor-dependent. Osmotic adjustments of 0.27 and 0.60 MPa were observed at the end of the first and second stress period, respectively. Relative apoplastic water content (RWCa) values were high, ranging from 27 to 42%, and were not affected by water stress. The rapid decrease in leaf conductance (gl) from the beginning of the stress periods, together with the delay in stomatal reopening after rewatering the plants, indicated that stomatal behaviour was not a simple passive response to water deficits. Net photosynthesis decreased only at the end of both stress periods and recovered quickly. These observations indicate that leaf productivity may be affected only slightly by short-term water stress. The results indicate that drought resistance in apricot is based mainly on avoidance mechanisms, such as stomatal control, epinasty and limitation of transpiration by reducing leaf area. However, some tolerance characteristics, including osmotic adjustment, high RWCa and low leaf osmotic potential at turgor loss point (Ytlp) values were observed.The authors are grateful to J. Soto-Montesinos, M.D. Velasco, M. García and E. Nicolás for their assistance. The study was supported by CICYT (AMB95- 0071) and Consejería de Medio Ambiente, Agricultura y Agua de Murcia grants to the authors

    The Rap Net: a geodetic positioning network for Andalusia (South Spain)

    Get PDF
    In this paper we present a description of the Andalusian Positioning Network, RAP: its objectives; design; development; its problems and its present status. This geodetic network consists of 22 permanent GPS stations whose surveying will provide the data required to obtain relative positions of any place in Andalusia after applying some post-processing techniques and real-time differential corrections. Thus, high-precision geodetic coordinates referred to the WGS-84 system will be provided for anywhere in Andalusia. The station in the network can broadcast a differential correction via internet. Nine stations can also broadcast the RTK corrections via radio. The network has been designed to cover Andalusia and to provide real-time differential corrections in the whole area. The RAP network is referred to the EUREF system and is the new reference frame in Andalusia for the Institute of Cartography of Andalusia’s new cartography. It will also be used to settle photogrametric points or marks for the georeferencing of satellite images; to establish control points for reference networks in civil engineering or GIS applications; for numerous scientific and technological applications, such as precise geoid determination and tropospheric, ionospheric, and climatological studies, among others. Its millimetric precision will ensure success when integrating new projects with other cartographies

    Economic and environmental sustainability of submerged anaerobic MBR based (AnMBR-based) technology compared to aerobic-based technologies for moderate-/high-loaded urban wastewater treatment

    Full text link
    [EN] The objective of this study was to assess the economic and environmental sustainability of submerged anaerobic membrane bioreactors (AnMBRs) in comparison with aerobic-based technologies for moderate-/high-loaded urban wastewater (UWW) treatment. To this aim, a combined approach of steady-state performance modelling, life cycle analysis (LCA) and life cycle costing (LCC) was used, in which AnMBR (coupled with an aerobic-based post-treatment) was compared to aerobic membrane bioreactor (AeMBR) and conventional activated sludge (CAS). AnMBR with CAS-based post-treatment for nutrient removal was identified as a sustainable option for moderate-/high-loaded UWW treatment: low energy consumption and reduced sludge production could be obtained at given operating conditions. In addition, significant reductions can be achieved in different aspects of environmental impact (global warming potential (GWP), abiotic depletion, acidification, etc.) and LCC over existing UWW treatment technologies.Pretel, R.; Robles Martínez, Á.; Ruano García, MV.; Seco Torrecillas, A.; Ferrer, J. (2016). Economic and environmental sustainability of submerged anaerobic MBR based (AnMBR-based) technology compared to aerobic-based technologies for moderate-/high-loaded urban wastewater treatment. Journal of Environmental Management. 166:45-54. https://doi.org/10.1016/j.jenvman.2015.10.004S455416

    Environmental impact of submerged anaerobic MBR (SAnMBR) technology used to treat urban wastewater at different temperatures

    Full text link
    [EN] The objective of this study was to assess the environmental impact of a submerged anaerobic MBR (SAnMBR) system in the treatment of urban wastewater at different temperatures: ambient temperature (20 and 33 degrees C), and a controlled temperature (33 degrees C). To this end, an overall energy balance (OEB) and life cycle assessment (LCA), both based on real process data, were carried out. Four factors were considered in this study; (1) energy consumption during wastewater treatment; (2) energy recovered from biogas capture; (3) potential recovery of nutrients from the final effluent; and (4) sludge disposal. The OEB and LCA showed SAnMBR to be a promising technology for treating urban wastewater at ambient temperature (OEB = 0.19 kW h m(-3)). LCA results reinforce the importance of maximising the recovery of nutrients (environmental impact in eutrophication can be reduced up to 45%) and dissolved methane (positive environmental impact can be obtained) from SAnMBR effluent. (C) 2013 Elsevier Ltd. All rights reserved.This research work has been supported by the Spanish Ministry of Science and Innovation (MICINN, Project CTM2011-28595-CO2-01/02) jointly with the European Regional Development Fund (ERDF) which are gratefully acknowledged.Pretel, R.; Robles Martínez, Á.; Ruano García, MV.; Seco Torrecillas, A.; Ferrer, J. (2013). Environmental impact of submerged anaerobic MBR (SAnMBR) technology used to treat urban wastewater at different temperatures. Bioresource Technology. 149:532-540. https://doi.org/10.1016/j.biortech.2013.09.060S53254014

    Pre-torsors and Galois comodules over mixed distributive laws

    Full text link
    We study comodule functors for comonads arising from mixed distributive laws. Their Galois property is reformulated in terms of a (so-called) regular arrow in Street's bicategory of comonads. Between categories possessing equalizers, we introduce the notion of a regular adjunction. An equivalence is proven between the category of pre-torsors over two regular adjunctions (NA,RA)(N_A,R_A) and (NB,RB)(N_B,R_B) on one hand, and the category of regular comonad arrows (RA,ξ)(R_A,\xi) from some equalizer preserving comonad C{\mathbb C} to NBRBN_BR_B on the other. This generalizes a known relationship between pre-torsors over equal commutative rings and Galois objects of coalgebras.Developing a bi-Galois theory of comonads, we show that a pre-torsor over regular adjunctions determines also a second (equalizer preserving) comonad D{\mathbb D} and a co-regular comonad arrow from D{\mathbb D} to NARAN_A R_A, such that the comodule categories of C{\mathbb C} and D{\mathbb D} are equivalent.Comment: 34 pages LaTeX file. v2: a few typos correcte

    Challenges and Opportunities for Spark Plasma Sintering: A Key Technology for a New Generation of Materials

    Get PDF
    This is an open access article distributed under the terms of the Creative Commons Attribution License.-- et al.Peer reviewe
    corecore