Discrete analysis of dividend payments in a non-life insurance portfolio

The process of free reserves in a non-life insurance portfolio as defined in the classical model of risk theory is modified by the introduction of dividend policies that set maximum levels for the accumulation of reserves. The first part of the work formulates the quantification of the dividend payments via the expectation of their current value under different hypotheses. The second part presents a solution based on a system of linear equations for discrete dividend payments in the case of a constant dividend barrier, illustrated by solving a specific case.dividend policies, expected present value

Exploring GHG emissions in the mainstream SCEPPHAR configuration during wastewater resource recovery

Acord transformatiu CRUE-CSICThe wastewater sector paradigm is shifting from wastewater treatment to resource recovery. In addition, concerns regarding sustainability during the operation have increased. In this sense, many water utilities have become aware of the potential GHG emissions during the operation of wastewater treatment. This study assesses the nitrous oxide and methane emissions during the long-term operation of a novel wastewater resource recovery facility (WRRF) configuration: the mainstream SCEPPHAR. The long-term NO and CH emission factors calculated were in the low range of the literature, 1 % and 0.1 %, respectively, even with high nitrite accumulation in the case of NO. The dynamics and possible sources of production of these emissions are discussed. Finally, different aeration strategies were implemented to study the impact on the NO emissions in the nitrifying reactor. Results showed that operating the pilot-plant under different dissolved oxygen concentrations (between 1 and 3 g O m) did not have an effect on the NO emission factor. Intermittent aeration was the aeration strategy that most mitigated the NO emissions in the nitrifying reactor, obtaining a reduction of 40 % compared to the normal operation of the pilot plant

Puesta a punto de la técnica Hole Drilling en el análisis estructural in situ de elementos portantes de madera

301 p.La técnica Hole Drilling puede suponer un pilar fundamental en la inspección estructural de elementos portantes de madera en los edificios existentes. Hole Drilling es una técnica de relajación de tensiones residuales conocida por su aplicación en otros materiales tecnológicos. Esta Tesis Doctoral afirma que la técnica es apta y útil para medir tensiones de origen estructural en elementos portantes de madera. Se ha ensayado en madera de pino radiata procedente de la CAPV pero es extensible a otras especies, como el roble.La técnica de aplicación in situ es capaz de determinar el estado tensional real y actualizado de un determinado elemento estructural de madera. La nueva aplicación de la técnica puede ayudar a los técnicos competentes en la inspección y la toma de decisiones en los proyectos de restauración o rehabilitación estructural. Se fomenta la conservación de elementos estructurales de madera, que de otra manera serían sustituidos por otros. En la Tesis Doctoral se han realizado ensayos de laboratorio en piezas estructurales tanto a compresión como a flexión y se ha aplicado, finalmente, en estructuras reales de edificios existentes, dando lugar a resultados muy satisfactorios

NEU screen shows high accuracy in detecting cognitive impairment in older persons living with HIV

The NEUrocognitive (NEU) Screen is a practical tool proposed to screen for HIV-associated cognitive impairment in the clinical setting. This is a pencil-and-paper method that can be applied rapidly (<=10 minutes for administration) and has no copyright limitations. In this study, we aimed at investigating its diagnostic accuracy in an older population of persons living with HIV (PLWH), with cutoffs set at 30, 40, 50, and 60 years. Data were collected from a sample of 368 PLWH who underwent a comprehensive neuropsychological tests battery (gold standard). Results of statistical tests showed that accuracy of the NEU Screen increased with age of the participants. The highest degree of precision, with a sensitivity of 91% and specificity of 92%, was obtained for people ages 60 years or older (correct classification: 91%). These optimal results point to the great potential of the NEU Screen as a tool for detecting cognitive disorders in older PLWH

Synthesising Liberal Normative Systems

Norms have been extensively studied to coordinate multi-agent systems, and the literature has investigated two general approaches to norm synthesis: off-line (synthesising norms at design-time) and on-line (run-time synthesis). On-line synthesis is generally recognised to be appropriate for open systems, where aspects of the system remain unknown at design-time. In this paper we present LION, an algorithm aimed at synthesising liberal normative systems. lion's normative systems respect the agents' autonomy to the greatest possible extent, constraining their behaviour when only necessary to avoid undesirable system states, lion's norm synthesis is also driven by the need to construct compact normative systems. The key to the success of lion in this multi-objective synthesis process is that it learns about and exploits norm synergies. More precisely, lion can learn when norms are either substitutable or complementary. We show empirically that LION significantly outperforms the state of the art by synthesising normative systems that are more liberal while maintaining representation compactness. Copyright © 2015, International Foundation for Autonomous Agents and Multiagent Systems.Work funded by projects AT (CSD2007-0022), COR (TIN2012-38876-C02-01, TIN2012-38876-C02-02), and 2009-SGR-1434. Mike Wooldridge was supported by the ERC under Advanced Grant 291528 (“RACE")Peer reviewe

Minimality and Simplicity in the On-line Automated Synthesis of Normative Systems

Much previous research has investigated explicit, machine-process-able norms as a means to facilitate coordination in open multi-agent systems. This research can typically be classified as considering either offline design (norms are synthesised at design time) or online design. Online synthesis techniques aim to construct norms for a system while that system is actually running. A promising recent approach to on-line norm synthesis has been proposed but it suffers from serious drawbacks: (i) it needs too much information; (ii) it ignores issues of compactness in terms of minimality (ensuring that norms are not superfluous) and simplicity (ensuring that agents can process norms with little computational effort). To overcome these drawbacks, we propose an optimistic approach which, even though it uses less information, is able to explore more norms and synthesises sets of norms which are more compact. We present experimental evidence of the quality of our approach. Copyright © 2014, International Foundation for Autonomous Agents and Multiagent Systems (www.ifaamas.org). All rights reserved.Peer Reviewe

Politicas de dividendos y probabilidad de ruina

In this paper we introduce different kinds of dividend barriers in the classical model ruin theory. We study the influence of barrier strategy on ruin probability. A method based on renewal equations [Grandell (1991)], alternative to differential argument [Gerber (1975)], is used to get the partial differential equations to solve survival probabilities. Finally we calculate and compare the survival probabilities using the linear and the parabolic dividend barrier, with help of simulation.ruin, survival probability, theory, dividend barriers

Matching Rheology, Conductivity and Joule Effect in PU/CNT Nanocomposites

We investigated polyurethane (PU)–carbon nanotube (CNT) nanocomposites (PU/CNT) in a range of concentrations from 1 to 8 wt% CNT as hot melt adhesives. We studied the thermal properties of the nanocomposites, which is relevant from an applied point of view. The phase angle plots versus complex modulus results revealed the existence of a maximum above a given CNT concentration. The intensity of the peak and associated relaxation time was analyzed with percolation theory, leading to a new method to determine the rheological percolation threshold. A lower threshold value was obtained from the electrical conductivity data, which was justified recalling that the hopping/tunnelling effect takes place in the nanocomposite, as stated by previous studies in the literature. Joule effect studies indicated that the heating effect was very significant, reaching temperature increases, ΔT, of 60 °C for low voltages. For the first time, the percolation equation was applied to the ΔT to obtain the corresponding threshold. Stimulus-responsive systems were conceived considering the correlation between the ΔT and the conductivity. The case of PU/CNT nanocomposites acting as hot melt adhesives that are welded/unglued by applying/removing an electrical voltage is presented.This research was funded by Basque Government, grant number IT1309-19. L.S. acknowledges the postdoctoral grant from Basque Government

Applying IRON to a Virtual Community Scenario

Normative systems (norms) have been widely proposed as a technique for coordinating multi-agent systems (MAS). The automated synthesis of norms is a complex problem that remains open. IRON (Intelligent Robust On-line Norm synthesis mechanism) is a novel mechanism for the on-line automated synthesis of norms for MASs. IRON produces conflict-free norms that characterise necessary conditions for coordination, without over-regulation. In the past, IRON successfully regulated a traffic scenario even in the presence of non-compliant agents. In this paper, we apply IRON to synthesise norms for a virtual community scenario, where agents are users that share contents within the community. As a result, IRON synthesises norms that prevent users from uploading undesirable contents (i.e., those that users complain about). © 2013 The authors and IOS Press. All rights reserved.This work was funded by AT (CONSOLIDER CSD2007-0022), EVE (TIN2009-14702-C02-01/02), COR (TIN2012-38876-C02-01/02), MECER (201250E053) and the Generalitat of Catalunya (2009-SGR-1434).Peer Reviewe