Search results for " coordination"
showing 10 items of 215 documents
An Investigation of Protection Devices Coordination Effects on Distributed Generators Capacity in Radial Distribution Systems
2013
In the recent years, with the concept of Smart Grid, there are a great interest in integration of renewable energy based distributed generation (DG) units at distribution level. Along with a number of benefits, penetration of DG units in the distribution system imposes some serious challenges; protection requirements turns up as one of the most critical challenge in DG integration. In this paper the possibility and the potentiality of occurring mis-coordination between protection devices in radial distribution network is studied. The impacts of protection devices coordination on DG capacity are investigated. The penetration level, number, and location of interconnected DGs are used as param…
MECANISMOS DE COORDINACIÓN ESTRUCTURAL, NO ESTRUCTURAL E INFORMAL. PROPUESTA Y VALIDACIÓN DE ESCALAS DE MEDIDA / STRUCTURAL, NON- STRUCTURAL AND INFO…
2008
El presente trabajo tiene como objetivo diseñar y validar escalas para medir diversos mecanismos de coordinación estructural, no estructural e informal. Los primeros están vinculados a puestos u órganos específicos, y nos referimos al diseño de redes, equipos de proyecto y desarrollo, y equipos de trabajo. Los mecanismos de coordinación no estructural sirven de complemento a los anteriores. En este grupo se encuentran la normalización de procesos de trabajo, de habilidades y de resultados. Por último, los mecanismos de carácter informal son el esfuerzo de socialización y la adaptación mutua. Tras la generación de una batería de 43 ítems, se han comprobado sus propiedades psicométricas: fiab…
Europa social: cuestiones para un futuro debate
2021
El presente trabajo tiene por objeto abordar determinadas cuestiones que, a juicio de la autora, deberían ser tratadas en un futuro debate sobre la Europa social. Para ello, se presentará, como punto de partida, la situación actual del denominado Modelo social europeo a partir de un recorrido por la configuración de las diferentes técnicas de creación del derecho social europeo: armonización de las legislaciones, diálogo social, método abierto de coordinación y ¿constitucionalización¿ de los derechos sociales. Una segunda parte del trabajo se dedicará a plantear ciertos temas concretos que deberían ser objeto de tratamiento en el futuro, entre ellos, los siguientes: la reformulación del art…
Impact of LTE’s Periodic Interference on Heterogeneous Wi-Fi Transmissions
2018
The problem of Wi-Fi and LTE coexistence has been significantly debated in the last years, with the emergence of LTE extensions enabling the utilization of unlicensed spectrum for carrier aggregation. Rather than focusing on the problem of resource sharing between the two technologies, in this paper, we study the effects of LTE's structured transmissions on the Wi-Fi random access protocol. We show how the scheduling of periodic LTE transmissions modifies the behavior of 802.11's distributed coordination function (DCF), leading to a degradation of Wi-Fi performance, both in terms of channel utilization efficiency and in terms of channel access fairness. We also discuss the applicability and…
MAC Design for WiFi Infrastructure Networks: A Game-Theoretic Approach
2011
In WiFi networks, mobile nodes compete for accessing a shared channel by means of a random access protocol called Distributed Coordination Function (DCF). Although this protocol is in principle fair, since all the stations have the same probability to transmit on the channel, it has been shown that unfair behaviors may emerge in actual networking scenarios because of non-standard configurations of the nodes. Due to the proliferation of open source drivers and programmable cards, enabling an easy customization of the channel access policies, we propose a game-theoretic analysis of random access schemes. Assuming that each node is rational and implements a best response strategy, we show that…
An ecological dynamics rationale to explain home advantage in professional football
2016
Despite clear findings, research on home advantage in team sports lacks a comprehensive theoretical rationale for understanding why this phenomenon is so compelling. The aim of this study was to provide an explanatory theoretical rationale in ecological dynamics for the influence of home advantage observed in research on professional football. We recorded 30 competitive matches and analyzed 13958 passes, from one highly successful team in the Portuguese Premier League, during season 2010/2011. Performance data were analyzed using the Match Analysis Software—Amisco[Formula: see text] (version 3.3.7.25), allowing us to characterize team activity profiles. Results were interpreted from an ecol…
Seabirds mated for life migrate separately to the same places: behavioural coordination or shared proximate causes?
2015
Long-term pair bonds occur in diverse animal taxa, but they are most common in birds, and can last from a few years to a lifetime. In many of these species, after the reproductive season, birds migrate to distant nonbreeding grounds where they remain for several months, and until recently, little was known about whether partners maintain contact during migration. This gap in knowledge was primarily due to past methodological difficulties in tracking long-term, large-scale movements of individuals. However, the development of new animal-borne geolocation devices has enabled researchers to track movements of individuals for a year or more. We tracked the annual migrations of both members of b…
España inacabada. Organización territorial del Estado, autonomía política y reconocimiento de la diversidad nacional
2021
S’han complert més de tres dècades de vigència de la Constitució de 1978 i, per tant, ja es disposa de prou perspectiva per analitzar el grau d’eficàcia d’un model d’Estat, per alguns, gairebé federal i, per a uns altres, senzillament molt descentralitzat. D’altra banda, a Espanya segueix plenament obert el debat sobre Espanya. Sigui quina sigui l’opinió, la veritat és que el nostre antic problema consumeix una gran part de les energies col·lectives, condiciona àmpliament l’agenda política, genera notables tensions socials i projecta ombres d’incertesa respecte al futur. En aquest treball, s’hi presenta un balanç de les dues qüestions. Després d’oferir un resum breu del procés de construcci…
Cooperative RTS/CTS MAC with relay selection in distributed wireless networks
2009
This paper proposes a cooperative multiple access protocol based on the Distributed Coordination Function (DCF) Request-To-Send/Clear-To-Send (RTS/CTS) scheme for distributed wireless networks. It answers three key questions concerning cooperation from the network perspective, namely when to cooperate, whom to cooperate with and how to protect cooperative transmissions. According to our protocol, the cooperation is initiated only if the direct transmission fails. An optimal relay node is selected in a distributed manner according to instantaneous relay channel conditions without prior information or extra signaling among relay candidates in the network. An additional three-way handshake is …
Revisit of RTS/CTS Exchange in High-Speed IEEE 802.11 Networks
2005
IEEE 802.11 medium access control (MAC), called distributed coordination function (DCF), provides two different access modes, namely, 2-way (basic access) and 4-way (RTS/CTS) handshaking. The 4-way handshaking has been introduced in order to combat the hidden terminal phenomenon. It has been also proved that such a mechanism can be beneficial even in the absence of hidden terminals, because of the collision time reduction. We analyze the effectiveness of the RTS/CTS access mode, in current 802.11b and 802.11a networks. Since the rates employed for control frame transmissions can be much lower than the rate employed for data frames, the assumption on the basis of the 4-way handshaking introd…