Los precios en los mercados reestructurados de electricidad: algunas lecciones básicas para la negociación derivada

Este artículo investiga los precios al contado de mercados reestructurados de la electricidad de diversas partes del mundo. Primero se proporciona un análisis detallado de las propiedades distributivas y de la dinámica de los precios de contado eléctricos. Después se realiza una introducción a los múltiples factores por el lado de la demanda y de la oferta que contribuyen a su complejo y variado comportamiento. Finalmente se extraen algunas lecciones fundamentales del análisis anterior para la negociación de derivados sobre la electricidad.This paper investigates the spot prices from restructured electricity markets around the world. First, we provide a comprehensive survey of the distributional properties and the dynamics of spot electricity prices. Then, we introduce the multiple demand and supply factors that contribute to their complex and diverse behaviour. Finally, we extract some fundamental lessons implied by such characteristics, for the power [email protected]

Desarrollo de una plataforma experimental de mecanismos de control de potencia a nivel MAC en redes de sensores

[ENG]This project was designed trying to verify the theoretical studies published in the article “Performance Evaluation of MAC Transmission Power Control in Wireless Sensor Networks” [1]. This article presents several analytic methods that allow to computing the energy saving provided by the use of transmission power control (TPC) mechanisms at MAC protocols in wireless sensor networks. It concludes that, when implementing these mechanisms at a protocol such as S-MAC, energy savings could reach up to 10 %. The goal of this project is to develop an experimental platform which allows to objectively evaluate the energy consumption in wireless sensor networks. The project is divided in two main areas; the first one is the implementation of a Transmission Power Control (TPC) mechanism over Sensor-Medium Access Control (S-MAC) in the sensors, while the other one is the need to develop a platform which evaluates the energy savings produced by this implementation. While tests were done under controlled conditions, some irregularities were found. This opens a new develop line which would allow to explain these irregularities and, thus, avoid them.[SPA]El presente proyecto nace como un intento de verificación de los estudios teóricos publicados en el artículo “Performance Evaluation of MAC Transmission Power Control in Wireless Sensor Networks” [1]. En dicho artículo se desarrolla una serie de métodos analíticos que permiten calcular el ahorro de energía proporcionado por la implementación de mecanismos TPC en protocolos Medium Access Control (MAC) para redes de sensores inalámbricos. El artículo concluye que, implementando estos mecanismos en un protocolo como S-MAC el ahorro podría llegar a ser de hasta un 10 %. El objetivo que se plantea es el desarrollo de una plataforma experimental que permita una evaluación objetiva del consumo energético en nodos de redes de sensores inalámbricos. El proyecto se divide en dos grandes áreas, por un lado se aborda la implementación en los sensores del TPC sobre S-MAC mientras que por otro se presenta la necesidad de desarrollar una plataforma que permita evaluar el ahorro energético que produce dicha implementación. Por otra parte, aunque la realización de las pruebas tuvo lugar en condiciones controladas, se presentan algunas irregularidades en las medidas que abren una futura línea de desarrollo que permita explicarlas y, en consecuencia, evitarlas.Escueal Técnica Superior de Ingeniería de Telecomunicació

Simulación y evaluación de prestaciones de un protocolo ARQ cooperativo con múltiples relays

[SPA]La evolución de las redes de acceso radio hacia tecnologías 4G implica un aumento considerable en los anchos de banda. A velocidades binarias muy altas las tasas de errores en la transmisión son cada vez mayores, por lo que hace falta una mayor potencia de señal en todo el área de cobertura. Una estrategia factible es el uso de pequeños repetidores denominados relays que implementen algún tipo de protocolo ARQ cooperativo (C-ARQ). La idea de funcionamiento es muy sencilla. En un canal inalámbrico las tramas pueden llegar dañadas al receptor. Actualmente la solución consiste retransmitir las tramas cuando se detecta que se han perdido (ARQ). Si un relay ha recibido la trama perdida, puede ayudar al transmisor retransmitiendo una copia de la trama perdida al mismo tiempo que lo hace el transmisor (C-ARQ). En C-ARQ con múltiples relays, más de un nodo relay puede retransmitir simultáneamente la información hacia un mismo receptor. El objetivo del proyecto es implementar la funcionalidad C-ARQ con múltiples relays, partiendo de un simulador C-ARQ para un solo relay y, posteriormente, evaluar su rendimiento en distintas configuraciones. [ENG]The evolution of radio access networks towards 4G technologies implies a big increase on bandwidth. At very high binary rates, the error rates are increasingly bigger, so a higher power signal is required all over the coverage area. A feasible strategy consists on using relays with some kind of C-ARQ protocol. The idea is really simple. In a wireless channel the frames can arrive with errors to the receiver. Nowadays, the solution consists on forwarding the frames when it is detected that they have been lost (ARQ). When a relay receives a lost frame, it can help the base station by forwarding a copy of that frame simultaneously with the base station (C-ARQ). In that scenario with multiple relays, more than one relay node can forward simultaneously the information towards the same receiver. The goal of this project is to develop the multiple relay C-ARQ protocol, starting from a C-ARQ simulator for a single relay and then, make a performance evaluation for different configurations.Escuela Técnica Superior de Ingeniería de Telecomunicació

On the Design of Ambient Intelligent Systems in the Context of Assistive Technologies

The design of Ambient Intelligent Systems (AISs) is discussed in the context of assistive technologies. The main issues include ubiquitous communications, context awareness, natural interactions and heterogeneity, which are analyzed using some examples. A layered architecture is proposed for heterogeneous sub-systems integration with three levels of interactions that may be used as a framework to design assistive AISs.Ministerio de Ciencia y Tecnología TIC2001-1868-C0

Subulura lacertilia sp.n. (Nematoda, Subuluridae) parasitizing the Brazilian lizard Tropidurus nanuzae Rodrigues (Lacertilia, Tropiduridae)

This report deals with the identification of samples of nematodes recovered from Tropidurus nanuzae Rodrigues, 1981, with the description of a new species, and is a part of a major study on helminth parasites of reptiles in Brazil, taking into account previous data on this subject. The main approach is that referring to the first occurrence of subulurid nematodes in a reptilian host, since they have been assigned previously to birds and mammals.10651068Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Alguns Helmintos de peixes do litoral norte fluminense - II

De 62 autópsias realizadas empeixes, capturados no litoral de Macaé, Estado do Rio de Janeiro, os autores coletaram alguns exemplares de helmintos cujo estudo permitiu a descrição de 2 espécies novas: Cucullanus rougetae e Raphidascaris yamagutii; a redescrição de Pseudopecoelus elongatus (Yamaguti, 1938) em novo hospedeiro, as referências de Procamallanus macaensis Vicente e Santos, 1972, e Catarinatrema verrucosum Freitas & Santos, 1971 e a descrição de 2 larvas de nematódeos e 1 de cestódeo que não puderam ser determinadas até espécie. A excursão emque foram colecionados os helmintos acima relacionados foi realizada em janeiro de 1973 por um de nós (elias dos Santos) permitindo a continuação de trabalho anterior sobre helmintos de peixes marinhos daquele município fluminense.Several helminths were recovered, buy one of the authors (Elias dos Santos) from fishes obtained in Macaé Coast, Rio de Janeiro State, Brasil, during an excursion in January, 1973. Two new species are described; Cucullanus rougetae and Raphidascaris yamagutii, they redescribe and give new host records for Pseudopecoellus elongatus (Yamaguti, 1938) and Procamallanus macaensis vicente e Santos, 1972; the later is only refered, as well as Catarinatrema verrucosum Freitas e santos, 1971. The describe one cestode and two nematode larvae although they could not be determinated. This is the second publication on the matter

Sydowia polyspora dominates fungal communities carried by two Tomicus species in pine plantations threatened by Fusarium circinatum

Producción CientíficaBark beetles (Coleoptera, Scolytinae) carry a diverse filamentous fungal community sometimes acting as vectors or carriers of phytopathogens. In this study, mycobiota carried by two Tomicus species (Tomicus piniperda and Tomicus destruens) were investigated through (i) morphological and molecular identification of taxa; (ii) taxonomic richness, diversity, evenness, dominance and phoresy indices; (iii) ecological network analysis and (iv) statistical co-occurrence analysis. The studied mycobiota were formed by eleven taxa and showed a moderate fungal diversity with low evenness. The fungus Sydowia polyspora was significantly abundant and dominated the community. All the fungal taxa were randomly associated. Both insect species (T. piniperda and T. destruens) were collected from plantations of Pinus radiata infected by Fusarium circinatum. The ecological factors that could drive community ecology and phoretic links between fungi and bark beetles are discussed.Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project AGL2015-69370-R)Ministerio de Economía, Industria y Competitividad (project AGL2012-39912)Junta de Castilla y León - Fondo Europeo de Desarrollo Regional (grant ORDEN EDU/1083/2013

On some family related parasites (Nematoda, Cucullanidae) from the marine fish Paralonchurus brasiliensis (Steindachner, 1875) (Pisces, Ostraciidae)

Dichelyne (Cucullanellus) elongatus (Tornquist, 1931) Petter, 1974 and Cucullanus pulcherrimus Barreto, 1918, from Paralonchurus brasiliensis (Steind., 1875) are redescribed and two specimens of Dichelyne (Cucullanellus) sp. are also reported in this host, despite lack of previously, was again identified in Brazil since its original description and posterior illustration. The present findings represent also a new host record for the referred genera: Dichelyne Jagerskiold, 1902 and Cucullanus Mueller, 1777. D. (C.) elongatus is also referred in Brazil for the first time

Further results on entanglement detection and quantification from the correlation matrix criterion

The correlation matrix (CM) criterion is a recently derived powerful sufficient condition for the presence of entanglement in bipartite quantum states of arbitrary dimensions. It has been shown that it can be stronger than the positive partial transpose (PPT) criterion, as well as the computable cross norm or realignment (CCNR) criterion in different situations. However, it remained as an open question whether there existed sets of states for which the CM criterion could be stronger than both criteria simultaneously. Here, we give an affirmative answer to this question by providing examples of entangled states that scape detection by both the PPT and CCNR criteria whose entanglement is revealed by the CM condition. We also show that the CM can be used to measure the entanglement of pure states and obtain lower bounds for the entanglement measure known as tangle for general (mixed) states.Comment: 13 pages, no figures; added references, minor changes; section 4.3 added, to appear in J. Phys.

Spirura delicata sp. n. (Spiruridae, Spirurinae) from Leontocebus mystax (Callithrichidae) and a check list of other Nematodes of some brazilian primates

Spirura delicata sp. n. from Leontocebus mystax (Six) is proposed and compared to S. guianensis (Ortlepp, 1924) Chitwood, 1938, S. michiganensis Sandground, 1935 and S. nayarani Mirza & Basir, 1938. Their differentiation is based mainly on the size and shape of spicules. Identification of nematode samples recovered from primates along 60 years and presently deposited in the Oswaldo Cruz Helmintological Collection is provided herein through a check list. Some of them are reported in new hsots and/or geographical regions