Complejidad y participación: la senda de la invención estratégica

The epistemological basis of research-participative action in the so-called «paradigm of complexity» is plagued with misconceptions, imprecision and significant omissions. The appropriate and contextualised translation of concepts acquired from natural sciences for use in social sciences is particularly necessary in qualitative-structural and participative-dialectic methodological trends. This study focuses on the concepts of «entropy», «complexity» and «strategic action». Based on a general notion of complexity relating to the consideration of uncertainty, innovation and the contextualisation of systems, we may highlight the performance-related aspects indicative of actions implied by this paradigm. Thus, the authors argue that the conceptualisation of operations such as «acting in order to know» and «act knowing/know by acting», encompassed in the notion of «strategic invention», complement or exceed the scope of typical planning operations and even self-planning («knowing in order to act»). In short, the authors argue that these definitions are coherent with an ecosystemic perspective of the social and natural reality, where it is necessary to contextualise what is more or less complex in the world, in our knowledge of the world and in our practical actions when acting in the world. Consequently, research participative action methodologies would need to adopt this complex and ecosystemic epistemological perspective, and adopt a «strategic invention» approach in order to clarify the concepts imported from other scientific disciplines

Las Romerías de Almería: religiosidad, invento social y fiesta popular

En número dedicado a: Almerí

Incorporating boundary conditions in a stochastic volatility model for the numerical approximation of bond prices

Producción CientíficaIn this paper, we consider a two-factor interest rate model with stochastic volatil-ity, and we assume that the instantaneous interest rate follows a jump-diffusionprocess. In this kind of problems, a two-dimensional partial integro-differentialequation is derived for the values of zero-coupon bonds. To apply standardnumerical methods to this equation, it is customary to consider a boundeddomain and incorporate suitable boundary conditions. However, for thesetwo-dimensional interest rate models, there are not well-known boundary con-ditions, in general. Here, in order to approximate bond prices, we propose newboundary conditions, which maintain the discount function property of thezero-coupon bond price. Then, we illustrate the numerical approximation ofthe corresponding boundary value problem by means of an alternative directionimplicit method, which has been already applied for pricing options. We testthese boundary conditions with several interest rate pricing models.MEC-FEDER Grant MTM2017-85476-C2-P, Junta de Castilla y León Regional Grants VA041P17 (with European FEDERFunds), VA138G18 y VA148G1

Spatial distribution of HD-EMG improves identification of task and force in patients with incomplete spinal cord injury

Background: Recent studies show that spatial distribution of High Density surface EMG maps (HD-EMG) improves the identification of tasks and their corresponding contraction levels. However, in patients with incomplete spinal cord injury (iSCI), some nerves that control muscles are damaged, leaving some muscle parts without an innervation. Therefore, HD-EMG maps in patients with iSCI are affected by the injury and they can be different for every patient. The objective of this study is to investigate the spatial distribution of intensity in HD-EMG recordings to distinguish co-activation patterns for different tasks and effort levels in patients with iSCI. These patterns are evaluated to be used for extraction of motion intention.; Method: HD-EMG was recorded in patients during four isometric tasks of the forearm at three different effort levels. A linear discriminant classifier based on intensity and spatial features of HD-EMG maps of five upper-limb muscles was used to identify the attempted tasks. Task and force identification were evaluated for each patient individually, and the reliability of the identification was tested with respect to muscle fatigue and time interval between training and identification. Results: Three feature sets were analyzed in the identification: 1) intensity of the HD-EMG map, 2) intensity and center of gravity of HD-EMG maps and 3) intensity of a single differential EMG channel (gold standard).; Results show that the combination of intensity and spatial features in classification identifies tasks and effort levels properly (Acc = 98.8 %; S = 92.5 %; P = 93.2 %; SP = 99.4 %) and outperforms significantly the other two feature sets (p < 0.05).; Conclusion: In spite of the limited motor functionality, a specific co-activation pattern for each patient exists for both intensity, and spatial distribution of myoelectric activity. The spatial distribution is less sensitive than intensity to myoelectric changes that occur due to fatigue, and other time-dependent influences.Peer ReviewedPostprint (published version

Design of a thermoelectric generator with fast transient respose

Thermoelectric modules are currently used both in Peltier cooling and in Seebeck mode for electricity generation. The developments experienced in both cases depend essentially on two factors: the thermoelectric properties of the materials that form these elements (mainly semiconductors), and the external structure of the semiconductors. Figure of Merit Z is currently the best way of measuring the efficiency of semiconductors, as it relates to the intrinsic parameters of the semiconductor: Seebeck coefficient, thermal resistance, and thermal conductivity. When it comes to evaluating the complete structure, the Coefficient of Performance (COP) is used, relating the electrical power to the thermal power of the module. This paper develops a Thermoelectric Generator (TEG) structure which allows minimising the response time of the thermoelectric device, obtaining short working cycles and, therefore, a higher working frequency.Preprin

Prediction of isometric motor tasks and effort levels based on high-density EMG in patients with incomplete spinal cord injury

Objective. The development of modern assistive and rehabilitation devices requires reliable and easy-to-use methods to extract neural information for control of devices. Group-specific pattern recognition identifiers are influenced by inter-subject variability. Based on high-density EMG (HD-EMG) maps, our research group has already shown that inter-subject muscle activation patterns exist in a population of healthy subjects. The aim of this paper is to analyze muscle activation patterns associated with four tasks (flexion/extension of the elbow, and supination/pronation of the forearm) at three different effort levels in a group of patients with incomplete Spinal Cord Injury (iSCI). Approach. Muscle activation patterns were evaluated by the automatic identification of these four isometric tasks along with the identification of levels of voluntary contractions. Two types of classifiers were considered in the identification: linear discriminant analysis and support vector machine. Main results. Results show that performance of classification increases when combining features extracted from intensity and spatial information of HD-EMG maps (accuracy = 97.5%). Moreover, when compared to a population with injuries at different levels, a lower variability between activation maps was obtained within a group of patients with similar injury suggesting stronger task-specific and effort-level-specific co-activation patterns, which enable better prediction results. Significance. Despite the challenge of identifying both the four tasks and the three effort levels in patients with iSCI, promising results were obtained which support the use of HD-EMG features for providing useful information regarding motion and force intentionPeer ReviewedPostprint (author's final draft

Modelling and simulation of a thermoelectric structure with pellets of non-standard geometry and materials

The aim of this paper is to develop and manufacture a thermoelectric structure operating in Peltier mode with non-standard materials, using a Finite Element Model. Thus, both the reliability of the Finite Element Model and the correct development and design of the new thermoelectric structure are ascertained, achieving a dual goal of our research group. This work provides a very good correlation between simulated and experimental results, and corroborates that the material’s performance has a decisive influence on the thermoelectric properties of the structure in the temperature range of study considered.Peer ReviewedPostprint (author’s final draft

Crimen atrocissimum: prosecution and punishment of exceptional crimes and its representation in The Canterbury Tales

Este trabajo analiza algunos de los principales textos jurídicos que regulan el enjuiciamiento y castigo de los crímenes más graves en el derecho medieval inglés y su plasmación en la obra literaria de Geoffrey Chaucer. Se estudian también algunos rasgos fundamentales del marco jurídico de estos crímenes entre los siglos xii y xiv; se ejemplifican las especialidades procesales de estos delitos mediante el análisis del juicio y ejecución de Hugh Le Despenser (1286-1326); y se explora el tema de la violación desde la perspectiva que ofrecen la vida y obra de Geoffrey Chaucer, con especial atención a Los cuentos de Canterbury. Este autor presenta en su obra un nuevo contexto en el que se avanza notablemente en la clarificación conceptual, terminológica y tipológica de la violación como crimen horrendo, merecedor de la pena de muerte.This paper analyses some of the main legal texts that regulate the prosecution and punishment of exceptional crimes in medieval English law, and their transposition into Geoffrey Chaucer’s literary work. Some fundamental features of the legal framework for the prosecution of these crimes between the 12th and the 14th centuries are also studied; the procedural singularities of this type of prosecution are explored through the analysis of the trial and execution of Hugh Le Despenser (1286-1326) and through the rape theme in Geoffrey Chaucer’s works, with a particular focus on The Canterbury Tales. Chaucer writes in a new context, when conceptual, terminological and typological clarification of rape as a heinous crime against the person, a crime that carried the death penalty, was seeing significant progress