Themed issue on selected papers SEG2015: part II

This themed issue of Geomechanics for Energy and the Environment ‘SEG-2015-Part II’, presents papers selected from extended abstracts submitted to the Symposium on Energy Geotechnics (SEG-2015) held in the Civil Engineering School of the Universitat Politècnica de Catalunya in Barcelona, Spain, between June 2nd and 4th, 2015. This symposium SEG-2015 was the first event organized by the Technical Committee TC308 of the International Society for Soil Mechanics and Geotechnical Engineering, which will have continuity in the next symposium SEG-2018 to be held in the École Polytechnique Fédérale de Lausanne (Lausanne, Switzerland). The first issue ‘SEG-2015-Part I’ appeared just before the 1st International Conference on Energy Geotechnics (ICEG-2016), which was held in Kiel (Germany) at the end of August 2016. The second volume ‘SEG-2015-Part II’ on December 2016 will thus close a first cycle of successful conferences and publications along this initial stage of TC308.Peer ReviewedPostprint (author's final draft

Equilibrium plans in constrained environments

In this paper we analyze equilibria in competitive environments under constraints across players'' strategies. This means that the action taken by one player limits the possible choices of the other players. In this context the classical approach, Kakutani''s Fixed Point theorem, does not work. In particular, best replies against a given strategy profile may not be feasible. We extend Kakutani''s Fixed Point theorem to deal with the feasibility issue.Our main motivation to study this problem of co-dependency comes from the field of supply chain planning. A set of buyers is faced with external demand over a planning horizon, and to satisfy this demand they request inputs from a set of suppliers. Both suppliers and buyers face production capacities and the planning is made in a decentralized manner. A well-known coordination scheme for this setting is the upstream approach where the planning of the buyers is used to decide the request to the suppliers. We show the existence of equilibria for two versions of this coordination model. However, we illustrate with an example that the centralized solution is not, in general, an equilibrium, suggesting that regulation may be needed.We also apply our Fixed Point theorem to a production economy, where both supply and demand are upper bounded.operations research and management science;

Binarized support vector machines

The widely used Support Vector Machine (SVM) method has shown to yield very good results in Supervised Classification problems. Other methods such as Classification Trees have become more popular among practitioners than SVM thanks to their interpretability, which is an important issue in Data Mining. In this work, we propose an SVM-based method that automatically detects the most important predictor variables, and the role they play in the classifier. In particular, the proposed method is able to detect those values and intervals which are critical for the classification. The method involves the optimization of a Linear Programming problem, with a large number of decision variables. The numerical experience reported shows that a rather direct use of the standard Column-Generation strategy leads to a classification method which, in terms of classification ability, is competitive against the standard linear SVM and Classification Trees. Moreover, the proposed method is robust, i.e., it is stable in the presence of outliers and invariant to change of scale or measurement units of the predictor variables. When the complexity of the classifier is an important issue, a wrapper feature selection method is applied, yielding simpler, still competitive, classifiers

Ice formation in unsaturated frozen soils

This paper presents a procedure for determining unfrozen water saturation in a partially saturated frozen soil (clayey silt) using bulk electrical conductivity (EC) measurements. A modification of Archie’s law is proposed to describe the relationship between soil bulk EC, temperature, porosity and degree of unfrozen water saturation. Compacted samples have been prepared at a dry density around 1.90 Mg/m3 and at dif-ferent degrees of saturation. Samples have been then subjected to freezing paths up to -15 °C. Measurements of bulk EC along the temperature decrease and freezing paths have been used to calibrate parameters associ-ated with the proposed model. These calibrated models allow determining the amount of ice content for a given state of the partially saturated soil (porosity, initial degree of water saturation and temperature). The soil freezing retention curve has been also estimated by combining the Clausius-Clapeyron equation with water retention data on drying. A good agreement has been observed between the estimation based on EC measurements and results from water retention data, which validates the proposed procedure.Postprint (published version

The stigma of the proper name: A literary approach to the feminine onomastic of otherness

El objetivo principal de este artículo es llamar la atención sobre la onomástica literaria como mecanismo de alteridad. Las próximas páginas se proponen acercarse a los nombres propios más habituales que reciben los personajes femeninos marroquíes en la narrativa española de ficción escrita por mujeres durante el siglo XX. Se parte de la hipótesis de que el nombre propio atribuido a la otredad marroquí es mucho más que un signo lingüístico, funciona como un marcador identificativo del personaje dentro de una comunidad concreta y responde a una estrategia propia del principio de alteridad que permite diferenciar al «nosotros/as» del «ellos/as»The main objective of this article is to pay attention to the literary onomastics as a mechanism of otherness. The following pages propose to approach the most common names that Moroccan female characters receive in the Spanish fiction narrative written by women during the 20th century. It starts from the hypothesis that the proper name attributed to Moroccan otherness is much more than a linguistic sign, works as a marker identifying the character within a particular community and responds to its own strategy of the principle of otherness that allows to distinguish between us and the

Análisis de necesidades e intereses recreativos de las personas adultas mayores del albergue San José Obrero, del cantón de Siquirres: propuesta recreativa

Este artículo comprende el análisis de las necesidades y los intereses recreativos de las personas adultas mayores del "Albergue San José Obrero" del cantón de Siquirres, y una propuesta recreativa que se ajusta a sus requerimientos. El enfoque utilizado en esta investigación fue cualitativo de investigaciónacción y se utilizó la entrevista cualitativa, la discusión de grupo focal, la lista de cotejo y el diario de campo como instrumentos de medición. La información acerca de las necesidades e intereses recreativos se obtuvo por medio de un diagnóstico institucional, la información de la condición general de las personas adultas mayores y las opiniones de las personas adultas mayores acerca de sus experiencias y preferencias recreativas. La información obtenida se analizó mediante las técnicas de resumen y de sistematización. El estudio mostró la necesidad en esta población de mantener su condición física y cognoscitiva, su vinculación con la sociedad, el sentido de pertenencia al grupo y el sentido de utilidad y autosuficiencia; además del interés por participar en manualidades, paseos, actividades de aprendizaje, actividad física, siembra, pesca, cuentos, bingo y actividades culinarias. Con las conclusiones derivadas del diagnóstico se elaboró una propuesta recreativa que comprende la descripción detallada de 12 actividades recreativas para ser implementadas en la población investigada. Las actividades recreativas propuestas comprenden inducción a la recreación, actividades culinarias, manualidades, juegos de mesa, paseo, siembra, actividades físicas e intelectuales

The Agents-are-Substitutes Property in Continuous Generalized Assignment Problems

The VCG mechanism has some nice properties if the agents-are-substitutes property holds.For example, for combinatorial auctions the property assures that the VCG mechanism is supported by a pricing equilibrium. The existence of such a pricing equilibrium is a necessary condition for the existence of ascending auctions that are equivalent to the VCG mechanism.Although it is known that the agents-are-substitutes property is important in several settings few problems or subclasses of problems are proven to have the property.In this paper we show for a class of problems that the agents-are-substitutes property holds. Moreover we give two rather natural and small extensions that do not have this property in general.Furthermore we show that in our simple problem class we need the possibility of price discrimination.operations research and management science;

Binarized support vector machines

The widely used Support Vector Machine (SVM) method has shown to yield very good results in Supervised Classification problems. Other methods such as Classification Trees have become more popular among practitioners than SVM thanks to their interpretability, which is an important issue in Data Mining. In this work, we propose an SVM-based method that automatically detects the most important predictor variables, and the role they play in the classifier. In particular, the proposed method is able to detect those values and intervals which are critical for the classification. The method involves the optimization of a Linear Programming problem, with a large number of decision variables. The numerical experience reported shows that a rather direct use of the standard Column-Generation strategy leads to a classification method which, in terms of classification ability, is competitive against the standard linear SVM and Classification Trees. Moreover, the proposed method is robust, i.e., it is stable in the presence of outliers and invariant to change of scale or measurement units of the predictor variables. When the complexity of the classifier is an important issue, a wrapper feature selection method is applied, yielding simpler, still competitive, classifiers.Supervised classification, Binarization, Column generation, Support vector machines

Hygroscopicity issues in powder and grain technology

The effect of hygroscopicity on flowability of powders and bulk solids with applications in the packaging industry is experimentally and numerically investigated. Firstly, four granular materials are tested at different water contents to study the impact of relative humidity on some hydro-mechanical properties, namely the hydraulic diffusivity on wetting, as well as the shear strength and compressibility properties of the materials. Next, a capillary model covering a wider water content range –compared to the previous tests– is applied to discrete element simulations of a granular column collapse set-up. These simulations give further insight into important aspects of grain hygroscopicity in packaging and other industrial applications (such as the kinematics of flow and flowability issues), which are outside the scope of conventional experimental testing.Postprint (published version