Roaming in the Mobile Internet: when coverage sharing agreements call for regulation

Revised: 2006-06

Energy efficient area monitoring using information coverage in wireless sensor networks

In this paper, we are concerned with energy efficient area monitoring using information coverage in wireless sensor networks, where collaboration among multiple sensors can enable accurate sensing of a point in a given area-to-monitor even if that point falls outside the physical coverage of all the sensors. We refer to any set of sensors that can collectively sense all points in the entire area-to-monitor as a full area information cover. We first propose a low-complexity heuristic algorithm to obtain full area information covers. Using these covers, we then obtain the optimum schedule for activating the sensing activity of various sensors that maximizes the sensing lifetime. The scheduling of sensor activity using the optimum schedules obtained using the proposed algorithm is shown to achieve significantly longer sensing lifetimes compared to those achieved using physical coverage. Relaxing the full area coverage requirement to a partial area coverage (e.g., 95% of area coverage as adequate instead of 100% area coverage) further enhances the lifetime.

Optimal Guidance for Accurate Lunar Soft Landing with Minimum Fuel Consumption using Model Predictive Static Programming

In this paper the soft lunar landing with minimum fuel expenditure is formulated as a nonlinear optimal guidance problem. The realization of pinpoint soft landing with terminal velocity and position constraints is achieved using Model Predictive Static Programming (MPSP). The high accuracy of the terminal conditions is ensured as the formulation of the MPSP inherently poses final conditions as a set of hard constraints. The computational efficiency and fast convergence make the MPSP preferable for fixed final time onboard optimal guidance algorithm. It has also been observed that the minimum fuel requirement strongly depends on the choice of the final time (a critical point that is not given due importance in many literature). Hence, to optimally select the final time, a neural network is used to learn the mapping between various initial conditions in the domain of interest and the corresponding optimal flight time. To generate the training data set, the optimal final time is computed offline using a gradient based optimization technique. The effectiveness of the proposed method is demonstrated with rigorous simulation results.

Impacto solvencia II en un seguro de vida

La actividad aseguradora supone la transferencia de riesgos del asegurado al asegurador. El asegurador se compromete al pago de una prestación si el riesgo se realiza. Se produce un cambio en el ciclo productivo. El asegurador vende una cobertura sin conocer el momento y el coste exacto de dicha cobertura. Esta particularidad de la actividad aseguradora explica la necesidad para una entidad aseguradora de ser solvente en cada momento y ante cualquier imprevisto. Por ello, la solvencia de las entidades aseguradoras es un aspecto que se ha ido recogiendo en las distintas normativas que han regulado la actividad aseguradora y al que se ha ido dando cada vez más importancia. Actualmente la legislación vigente en materia de solvencia de las aseguradoras esta regulada por la directiva europea Solvencia I. Esta directiva establece dos conceptos para garantizar la solvencia: las provisiones técnicas y el margen de solvencia. Las provisiones técnicas son las calculadas para garantizar la solvencia estática de la compañía, es decir aquella que hace frente, en un instante temporal determinado, a los compromisos asumidos por la entidad. El margen de solvencia se destina a cubrir la solvencia dinámica, aquella que hace referencia a eventos futuros que puedan afectar la capacidad del asegurador. Sin embargo en una corriente de gestión global del riesgo en la que el sector bancario ya se había adelantado al sector asegurador con la normativa Basilea II, se decidió iniciar un proyecto europeo de reforma de Solvencia I y en noviembre del 2009 se adoptó la directiva 2009/138/CE del parlamento europeo y del consejo, sobre el seguro de vida, el acceso a la actividad de seguro y de reaseguro y su ejercicio mas conocida como Solvencia II. Esta directiva supone un profundo cambio en las reglas actuales de solvencia para las entidades aseguradoras. Este cambio persigue el objetivo de establecer un marco regulador común a nivel europeo que sea más adaptado al perfil de riesgo de cada entidad aseguradora. Esta nueva directiva define dos niveles distintos de capital: el SCR (requerimiento estándar de capital de solvencia) y el MCR (requerimiento mínimo de capital). Para el calculo del SCR se ha establecido que el asegurador tendrá la libertad de elegir entre dos modelos. Un modelo estándar propuesto por la Autoridad Europea de Seguros y Pensiones de Jubilación (EIOPA por sus siglas en inglés), que permitirá un calculo simple, y un modelo interno desarrollado por la propia entidad que deberá ser aprobado por las autoridades competentes. También se contempla la posibilidad de utilizar un modelo mixto que combine ambos, el estándar y el interno. Para el desarrollo del modelo estándar se han realizado una serie de estudios de impacto cuantitativos (QIS). El último estudio (QIS 5) ha sido el que ha planteado de forma más precisa el cálculo del SCR. Plantea unos shocks que se deberán de aplicar al balance de la entidad con el objetivo de estresarlo, y en base a los resultados obtenidos constituir el SCR. El objetivo de este trabajo es realizar una síntesis de las especificaciones técnicas del QIS5 para los seguros de vida y realizar una aplicación práctica para un seguro de vida mixto puro. En la aplicación práctica se determinarán los flujos de caja asociados a este producto para calcular su mejor estimación (Best estimate). Posteriormente se determinará el SCR aplicando los shocks para los riesgos de mortalidad, rescates y gastos. Por último, calcularemos el margen de riesgo asociado al SCR. Terminaremos el presente TFG con unas conclusiones, la bibliografía empleada así como un anexo con las tablas empleadas.

Private supervisors of learner drivers and Queensland's graduated driver licensing system : how important are they?

Background: A key element of graduated driver licensing systems is the level of support provided by parents. In mid-2007 changes were made to Queensland’s graduated driver licensing system, including amendments to the learner licence with one of the more significant changes requiring learners to record 100 hours of supervised driving practice in a logbook. Prior to mid-2007, there was no minimum supervision requirement. Aims: The aim of this study was to document the experiences of the supervisors of Queensland learner drivers after the changes made to the graduated driver licensing system in mid-2007. Methods: The sample of 552 supervisors of learner drivers was recruited using a combination of convenience and snowball sampling techniques. The internet survey was open for completion between July 2009 and May 2010 and took approximately 15 to 20 minutes for participants to complete. Results: For 59.7 per cent of the participants, this was the first time that they had supervised a learner driver. For 63.2 per cent, they classified themselves as the main supervisor for the learner driver. Participants provided an average of 79.62 hours of supervision (sd = 92.38), while other private supervisors provided 34.89 hours of supervision (sd = 41.74) to the same learner and professional driving instructors 18.55 hours of supervision (sd = 27.54). The vast majority of supervisors recorded all or most of the practice that they provided their learner driver in their log book with most supervisors indicating that they believed that the hours recorded in the learner’s logbook were either accurate or very accurate. While many supervisors stated that they did not receive any advice regarding the supervision of learner drivers, some had received advice from others such as friends or through discussions with a professional driving instructor. Discussion and conclusions: While graduated driver licensing systems implicitly encourage the involvement of parents and other private supervisors, these people tend not to be systematically involved. As demonstrated in this study, private supervisors provide a significant amount of supervised practice and seek to record this practice accurately and honestly in the learner’s logbook. However, even though a significant number of participants reported that this was the first time that they had supervised a learner driver, they accessed little support or guidance for their role. This suggests a need to more overtly encourage and support the role of private supervisors for learner drivers.

Role of the loop L-4,L-5 in allosteric regulation in mtHsp70s: in vivo significance of domain communication and its implications in protein translocation

Mitochondrial Hsp70 (mtHsp70) is essential for a vast repertoire of functions, including protein import, and requires effective interdomain communication for efficient partner-protein interactions. However, the in vivo functional significance of allosteric regulation in eukaryotes is poorly defined. Using integrated biochemical and yeast genetic approaches, we provide compelling evidence that a conserved substrate-binding domain (SBD) loop, L-4,L-5, plays a critical role in allosteric communication governing mtHsp70 chaperone functions across species. In yeast, a temperature-sensitive L-4,L-5 mutation (E467A) disrupts bidirectional domain communication, leading to compromised protein import and mitochondrial function. Loop L-4,L-5 functions synergistically with the linker in modulating the allosteric interface and conformational transitions between SBD and the nucleotide-binding domain (NBD), thus regulating interdomain communication. Second-site intragenic suppressors of E467A isolated within the SBD suppress domain communication defects by conformationally altering the allosteric interface, thereby restoring import and growth phenotypes. Strikingly, the suppressor mutations highlight that restoration of communication from NBD to SBD alone is the minimum essential requirement for effective in vivo function when primed at higher basal ATPase activity, mimicking the J-protein-bound state. Together these findings provide the first mechanistic insights into critical regions within the SBD of mtHsp70s regulating interdomain communication, thus highlighting its importance in protein translocation and mitochondrial biogenesis.

Boundary-layer suction system design for laminar-flying-wing aircraft

The present study aims to provide insight into the parameters affecting practical laminar-flow-control suction power requirements for a commercial laminar-flying-wing transport aircraft. It is shown that there is a minimum power requirement independent of the suction system design, associated with the stagnation pressure loss in the boundary layer. This requirement increases with aerofoil section thickness, but depends only weakly on Mach number and (for a thick, lightly loaded laminar flying wing) lift coefficient. Deviation from the optimal suction distribution, due to a practical chamber-based architecture, is found to have very little effect on the overall suction coefficient; hence, to a good approximation, the power penalty is given by the product of the optimal suction flow rate coefficient and the average skin pressure drop. In the spanwise direction, through suitable choice of chamber depth, the pressure drop due to frictional and inertial effects may be rendered negligible. Finally, if there are fewer pumps than chambers, the average pressure drop from the aerofoil surface to the pump collector ducts, rather than to the chambers, determines the power penalty. For the representative laminar-flying-wing aircraft parameters considered here, the minimum power associated with boundary-layer losses alone contributes some 80-90% of the total power requirement. © 2011 by the American Institute of Aeronautics and Astronautics, Inc.

A COMPARISON OF MARKET CLEARING TOOLS IN ELECTRICITY SYSTEMS

To maintain a strict balance between demand and supply in the US power systems, the Independent System Operators (ISOs) schedule power plants and determine electricity prices using a market clearing model. This model determines for each time period and power plant, the times of startup, shutdown, the amount of power production, and the provisioning of spinning and non-spinning power generation reserves, etc. Such a deterministic optimization model takes as input the characteristics of all the generating units such as their power generation installed capacity, ramp rates, minimum up and down time requirements, and marginal costs for production, as well as the forecast of intermittent energy such as wind and solar, along with the minimum reserve requirement of the whole system. This reserve requirement is determined based on the likelihood of outages on the supply side and on the levels of error forecasts in demand and intermittent generation. With increased installed capacity of intermittent renewable energy, determining the appropriate level of reserve requirements has become harder. Stochastic market clearing models have been proposed as an alternative to deterministic market clearing models. Rather than using a fixed reserve targets as an input, stochastic market clearing models take different scenarios of wind power into consideration and determine reserves schedule as output. Using a scaled version of the power generation system of PJM, a regional transmission organization (RTO) that coordinates the movement of wholesale electricity in all or parts of 13 states and the District of Columbia, and wind scenarios generated from BPA (Bonneville Power Administration) data, this paper explores a comparison of the performance between a stochastic and deterministic model in market clearing. The two models are compared in their ability to contribute to the affordability, reliability and sustainability of the electricity system, measured in terms of total operational costs, load shedding and air emissions. The process of building the models and running for tests indicate that a fair comparison is difficult to obtain due to the multi-dimensional performance metrics considered here, and the difficulty in setting up the parameters of the models in a way that does not advantage or disadvantage one modeling framework. Along these lines, this study explores the effect that model assumptions such as reserve requirements, value of lost load (VOLL) and wind spillage costs have on the comparison of the performance of stochastic vs deterministic market clearing models.

Systematic review of interventions to improve the psychological well-being of general practitioners

BACKGROUND: The health of doctors who work in primary care is threatened by workforce and workload issues. There is a need to find and appraise ways in which to protect their mental health, including how to achieve the broader, positive outcome of well-being. Our primary outcome was to evaluate systematically the research evidence regarding the effectiveness of interventions designed to improve General Practitioner (GP) well-being across two continua; psychopathology (mental ill-health focus) and 'languishing to flourishing' (positive mental health focus). In addition we explored the extent to which developments in well-being research may be integrated within existing approaches to design an intervention that will promote mental health and prevent mental illness among these doctors.

METHODS: Medline, Embase, Cinahl, PsychINFO, Cochrane Register of Trials and Web of Science were searched from inception to January 2015 for studies where General Practitioners and synonyms were the primary participants. Eligible interventions included mental ill-health prevention strategies (e.g. promotion of early help-seeking) and mental health promotion programmes (e.g. targeting the development of protective factors at individual and organizational levels). A control group was the minimum design requirement for study inclusion and primary outcomes had to be assessed by validated measures of well-being or mental ill-health. Titles and abstracts were assessed independently by two reviewers with 99 % agreement and full papers were appraised critically using validated tools.

RESULTS: Only four studies (with a total of 997 GPs) from 5392 titles met inclusion criteria. The studies reported statistically significant improvement in self-reported mental ill-health. Two interventions used cognitive-behavioural techniques, one was mindfulness-based and one fed-back GHQ scores and self-help information.

CONCLUSION: There is an urgent need for high quality, controlled studies in GP well-being. Research on improving GP well-being is limited by focusing mainly on stressors and not giving systematic attention to the development of positive mental health.

Basiléia II e exigência de capital para risco de crédito dos bancos no Brasil

Com a implementação do Acordo de Basiléia II no Brasil, os grandes conglomerados bancários poderão utilizar o chamado modelo IRB (Internal Ratings Based) para cômputo da parcela de risco de crédito da exigência de capital. O objetivo deste trabalho é mensurar a diferença entre o capital mínimo exigido (e, conseqüentemente, do Índice de Basiléia) calculado pela abordagem IRB em relação à regulamentação atual. Para isso, foram estimadas probabilidades de inadimplência (PD) utilizando matrizes de transição construídas a partir dos dados da Central de Risco de Crédito (SCR) do Banco Central do Brasil. Os resultados indicam aumento da exigência de capital, ao contrário do ocorrido nos países do G-10

Modelo interno de risco de crédito de Basiléia II: possíveis impactos no capital mínimo exigido dos bancos

Com a implementação do Acordo de Basiléia II no Brasil, os grandes conglomerados bancários poderão utilizar o chamado modelo IRB (Internal Ratings Based) para cômputo da parcela de risco de crédito da exigência de capital. O objetivo desta dissertação é mensurar a diferença entre o capital mínimo exigido (e, conseqüentemente, do Índice de Basiléia) calculado pela abordagem IRB em relação à regulamentação atual. Para isso, foram estimadas probabilidades de inadimplência (PD) utilizando matrizes de transição construídas a partir dos dados da Central de Risco de Crédito (SCR) do Banco Central do Brasil. Os resultados indicam aumento da exigência de capital, ao contrário do ocorrido nos países do G-10.

Exigência mínina de fósforo em novilhos da raça Nelore

A determinação da absorção real de fósforo (P) em bovinos deve levar em consideração a fração endógena mínina do mineral, que se perde nas fezes. de modo geral esses cálculos são feitos utilizando-se tabelas cujos valores foram obtidos em outros países, com outras raças de animais e em condições bem diferentes das condições brasileiras. O trabalho teve como objetivo determinar a perda endógena de P nas fezes e estimar a exigência mínima de P em novilhos da raça Nelore (Bos indicus). Foram utilizados 18 novilhos castrados, com peso médio de 190,82±27,53 kg e idade aproximada de 12 meses, divididos em três grupos de seis animais, e mantidos em gaiolas metabólicas individuais. Os animais receberam dieta básica constituída de feno de Brachiaria decumbens e uma mistura de concentrados durante os 30 dias de período experimental. Os tratamentos consistiram de diferentes quantidades de fosfato bicálcico em níveis de 0,12, 0,24 e 0,36% de P, com base na dieta total. Foram aplicadas injeções de 32P nos animais para a determinação da perda endógena fecal de P. A perda endógena mínima fecal de P para uma ingestão zero do mineral, calculada por interpolação, foi de 5,72 mg/kg de peso vivo e para um balanço zero, o requerimento mínimo foi de 8,84 mg/kg de peso vivo por dia.

Promoting corporate social responsibility in small and medium enterprises in the Caribbean: survey results

Includes bibliography

Polymorphisms in the trace amine receptor 4 (TRAR4) gene on chromosome 6q23.2 are associated with susceptibility to schizophrenia

Several linkage studies across multiple population groups provide convergent support for a susceptibility locus for schizophrenia - and, more recently, for bipolar disorder - on chromosome 6q13-q26. We genotyped 192 European-ancestry and African American (AA) pedigrees with schizophrenia from samples that previously showed linkage evidence to 6q13-q26, focusing on the MOXD1-STX7-TRARs gene cluster at 6q23.2, which contains a number of prime candidate genes for schizophrenia. Thirty-one screening single-nucleotide polymorphisms (SNPs) were selected, providing a minimum coverage of at least 1 SNP/20 kb. The association observed with rs4305745 (P = .0014) within the TRAR4 (trace amine receptor 4) gene remained significant after correction for multiple testing. Evidence for association was proportionally stronger in the smaller AA sample. We performed database searches and sequenced genomic DNA in a 30-proband subsample to obtain a high-density map of 23 SNPs spanning 21.6 kb of this gene. Single-SNP analyses and also haplotype analyses revealed that rs4305745 and/or two other polymorphisms in perfect linkage disequilibrium (LD) with rs4305745 appear to be the most likely variants underlying the association of the TRAR4 region with schizophrenia. Comparative genomic analyses further revealed that rs4305745 and/or the associated polymorphisms in complete LD with rs4305745 could potentially affect gene expression. Moreover, RT-PCR studies of various human tissues, including brain, confirm that TRAR4 is preferentially expressed in those brain regions that have been implicated in the pathophysiology of schizophrenia. These data provide strong preliminary evidence that TRAR4 is a candidate gene for schizophrenia; replication is currently being attempted in additional clinical samples.

Selective oxidation of cyclohexene through gold functionalized silica monolith microreactors

Two simple, reproducible methods of preparing evenly distributed Au nanoparticle containing mesoporous silica monoliths are investigated. These Au nanoparticle containing monoliths are subsequently investigated as flow reactors for the selective oxidation of cyclohexene. In the first strategy, the silica monolith was directly impregnated with Au nanoparticles during the formation of the monolith. The second approach was to pre-functionalize the monolith with thiol groups tethered within the silica mesostructure. These can act as evenly distributed anchors for the Au nanoparticles to be incorporated by flowing a Au nanoparticle solution through the thiol functionalized monolith. Both methods led to successfully achieving even distribution of Au nanoparticles along the length of the monolith as demonstrated by ICP-OES. However, the impregnation method led to strong agglomeration of the Au nanoparticles during subsequent heating steps while the thiol anchoring procedure maintained the nanoparticles in the range of 6.8 ± 1.4 nm. Both Au nanoparticle containing monoliths as well as samples with no Au incorporated were tested for the selective oxidation of cyclohexene under constant flow at 30 °C. The Au free materials were found to be catalytically inactive with Au being the minimum necessary requirement for the reaction to proceed. The impregnated Au-containing monolith was found to be less active than the thiol functionalized Au-containing material, attributable to the low metal surface area of the Au nanoparticles. The reaction on the thiol functionalized Au-containing monolith was found to depend strongly on the type of oxidant used: tert-butyl hydroperoxide (TBHP) was more active than H2O2, likely due to the thiol induced hydrophobicity in the monolith.