4,570 research outputs found
Risk aversion and debt maturity structure
We study the relationship of risk aversion and debt maturity structure. In a model in which adverse selection in financial markets creates a role for the use of short-term debt, we allow the possibility of borrowers being risk-averse. This creates a trade-off between reduced expected financing costs and higher risk and allows for the study of the effect of risk aversion on optimal maturity structure. We prove that, as risk aversion increases, so does the percentage of debt that is long-term.risk aversion, debt maturity structure, adverse selection.
Optimal security-constrained power scheduling by Benders decomposition
This paper presents a Benders decomposition approach to determine the optimal day-ahead power scheduling in a pool-organized power system, taking into account dispatch, network and security constraints. The study model considers the daily market and the technical constraints resolution as two different and consecutive processes. The daily market is solved in a first stage subject to economical criteria exclusively and then, the constraints solution algorithm is applied to this initial dispatch through the redispatching method. The Benders partitioning algorithm is applied to this constraints solution process to obtain an optimal secure power scheduling. The constraints solution includes a full AC network and security model to incorporate voltages magnitudes as they are a critical factor in some real power systems. The algorithm determines the active power committed to each generator so as to minimize the energy redispatch cost subject to dispatch, network and security constraints. The solution also provides the reactive power output of the generators, the value of the transformers taps and the committed voltage control devices. The model has been tested in the IEEE 24-bus Reliability Test System and in an adapted IEEE 118-bus Test System. It is programmed in GAMS mathematical modeling language. Some relevant results are reported.Publicad
Bilateral Asymmetries Assessment in Elite and Sub-Elite Male Futsal Players
This study aimed to investigate morphological, functional, and neuromuscular asymmetries on futsal players’ lower limbs at different competitive levels. Sixteen male elite futsal players from the Spanish National Futsal League and thirteen male sub-elite futsal players from the third division participated in this study. Morphological asymmetry was assessed through bioelectrical impedance (fat-mass (g and %) and lean-mass (g)). Functional asymmetry was assessed by means of a 20-s static unipedal balance test. Finally, neuromuscular asymmetry was assessed using tensiomiography tests on both the rectus femoris (RF) and biceps femoris (BF) of each participant. The three tests conducted did not reveal significant bilateral asymmetries in elite players. On the other hand, sub-elite players showed significant bilateral asymmetry in fat-mass percentage between dominant and non-dominant limbs (+6%; CI95%: 1 to 11; ES: 0.88; p = 0.019). They also showed higher bilateral asymmetry in the delay time of the RF (+13%; CI95%: 7 to 21; ES: 1.3; p 0.05) did not evidence asymmetries regardless of the level of the participants. Elite futsal players do not develop bilateral asymmetries in lower limbs in the studied parameters. On the contrary, sub-elite players are likely to develop morphological and neuromuscular asymmetries between their dominant leg and non-dominant leg.Sin financiación3.390 JCR (2020) Q1, 42/176 Public, Environmental & Occupational Health0.747 SJR (2020) Q2, 50/136 Health, Toxicology and MutagenesisNo data IDR 2020UE
Single-Board-Computer Clusters for Cloudlet Computing in Internet of Things
The number of connected sensors and devices is expected to increase to billions in the near
future. However, centralised cloud-computing data centres present various challenges to meet the
requirements inherent to Internet of Things (IoT) workloads, such as low latency, high throughput
and bandwidth constraints. Edge computing is becoming the standard computing paradigm for
latency-sensitive real-time IoT workloads, since it addresses the aforementioned limitations related
to centralised cloud-computing models. Such a paradigm relies on bringing computation close to
the source of data, which presents serious operational challenges for large-scale cloud-computing
providers. In this work, we present an architecture composed of low-cost Single-Board-Computer
clusters near to data sources, and centralised cloud-computing data centres. The proposed
cost-efficient model may be employed as an alternative to fog computing to meet real-time IoT
workload requirements while keeping scalability. We include an extensive empirical analysis to
assess the suitability of single-board-computer clusters as cost-effective edge-computing micro data
centres. Additionally, we compare the proposed architecture with traditional cloudlet and cloud
architectures, and evaluate them through extensive simulation. We finally show that acquisition costs
can be drastically reduced while keeping performance levels in data-intensive IoT use cases.Ministerio de Economía y Competitividad TIN2017-82113-C2-1-RMinisterio de Economía y Competitividad RTI2018-098062-A-I00European Union’s Horizon 2020 No. 754489Science Foundation Ireland grant 13/RC/209
New trends in education: the use of ICT in different ways
In the 21st century and due to the exponential growth of the Internet and Information and Communication
Technologies (ICT), people live in a technological age, in all areas and in all contexts, we have daily
contact with technology, with access to Information. This dynamic requires a constant update of the
services and technological tools that change the method that we study, work, communicate and socialize
on an unprecedented scale. These constant changes force everyone, regardless of age, gender or
profession, to possess a range of functional and critical thinking skills, such as information literacy,
media literacy and technological literacy. The evolution of technologies, forces the promoters of
education, to always be aware of the changes that society is introducing outside the classroom. Today,
students don't have the same pattern as before, regardless of age, they are very active and are no
longer the same introverted child who studied a few years ago in the classroom. According to this,
students are eager for different forms of motivation inside and outside the classroom, they need the
learning and teaching process to move along with changes in society and ICT. To ensure the success
of today's students, it is important to provide them with the technological skills to make the correct use
of ICTs, to perform tasks essential to their learning process, such as researching and selecting
information, creating content, information sharing, use of collaboration tools or environment simulation
tools. The main objective of this chapter is to show how ICT tools that can be used in educational
environments to help students, helping them develop key skills in their training process, is also relevant
to show how these tools can help teachers achieve these goals in daily activities with their students
Dinámicas de gentrificación en metrópolis de la cultura: aproximación comparada a las estrategias de Madrid y Buenos Aires
Este trabajo explora los cambios que acontecen actualmente en las dinámicas de regeneración urbana de las grandes metrópolis contemporáneas que apuestan por modelos de economía urbana incorporados a la globalización. El peso de la producción cultural y de las industria creativas se acompaña de nuevos personajes y estilos de vida directamente vinculados a la “nueva economía”, innovadora y social, cuyos movimientos representan hoy la piedra de toque de las dinámicas urbanas que afectan a las áreas centrales. Proponemos analizar estas dinámicas a partir de los casos de Madrid y Buenos Aires en función de tres factores detectados: la rehabilitación del patrimonio urbano, las políticas de lugar de la economía del conocimiento, y la transformación comercial de los mercados tradicionales y el comercio de proximidad. Sostenemos que estos tres vectores refuerzan los procesos de renovación urbana desplazando la frontera de la gentrificación a nuevos marcos de actuación y límites territoriales.This paper explores the changes taking place today in urban regeneration dynamics of the big metropolis that are committed to contemporary urban economic models incorporated in globalization. The weight of the cultural and creative industry comes together with new characters and lifestyles directly linked to the innovative and social "new economy", whose movements today represent the touchstone of urban dynamics
affecting central areas. We propose to analyze these dynamics from the cases of Madrid and Buenos Aires, in terms of three identified factors: the policies for rehabilitation of urban heritage, the policies for placing knowledge economy, and commercial transformation of traditional markets and local shops. We argue that
these three vectors reinforce urban renewal processes moving the border of gentrification towards new frameworks and territorial frontiers.Peer Reviewe
Contribución de los sitios web de la industria cinematográfica española a la percepción del Cine Español
A partir de la contribución que realizan las páginas web relacionadas con el sector cinematográfico en España a la imagen que proyectan, se trata de valorar si existe una buena utilización de estos recursos online para mejorar la percepción del cine que se produce en el estado español, a través del análisis cualitativo de los sitios web más relevantes, que hiciera más completos los resultados obtenidos al aplicarse a la totalidad de sitios web seleccionados. Concluimos que existe poco o casi nulo interés por cuidar una imagen que pudiera hacer crecer el interés del público por la industria cinematográfica española
Existence and uniqueness of positive large solutions to some cooperative elliptic systems
In this work we consider positive solutions to cooperative elliptic systems of the form −∆u = λu−u2 +buv, −∆v = µv −v2 +cuv in a bounded smooth domain Ω ⊂ RN (λ, µ ∈ R, b, c > 0) which blow up on the boundary ∂Ω, that is u(x), v(x) → +∞ as dist(x, ∂Ω) → 0. We show existence and nonexistence of solutions, and give sufficient conditions for uniqueness. We also provide an exact estimate of the behaviour of the solutions near the boundary in terms of dist(x, ∂Ω).Ministerio de Ciencia y Tecnologí
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