Search results for "Networks"
showing 10 items of 3260 documents
Hybrid passive and communications-based methods for islanding detection in medium and low voltage smart grids
2013
Islanding condition takes place when a distributed generator (DG) continues to power a part of the grid even if power from electric utility is no longer present. Adverse effects of islanding are power quality deterioration, grid-protection interference, equipment damage, and personnel safety hazards. For these reasons, DG systems must detect an islanding condition and immediately disconnect from the grid (anti-islanding protection). This paper proposes an hybrid solution, for both low voltage (LV) and medium voltage (MV) applications, which makes use of passive and communication-based methods for islanding detection. Among the existing communication technologies, the study is focused on pow…
Exploring FPGA‐Based Lock‐In Techniques for Brain Monitoring Applications
2017
Functional near‐infrared spectroscopy (fNIRS) systems for e‐health applications usually suffer from poor signal detection, mainly due to a low end‐to‐end signal‐to‐noise ratio of the electronics chain. Lock‐in amplifiers (LIA) historically represent a powerful technique helping to improve performance in such circumstances. In this work a digital LIA system, based on a Zynq® field programmable gate array (FPGA) has been designed and implemented, in an attempt to explore if this technique might improve fNIRS system performance. More broadly, FPGA‐based solution flexibility has been investigated, with particular emphasis applied to digital filter parameters, needed in the digital LIA, and its …
Flexible power converters for the fault tolerant operation of Micro-Grids
2010
The progressive penetration level of Distributed Generation (DG) is destined to cause deep changes in the existing distribution networks no longer considered as passive terminations of the whole electrical system. A possible solution is the realization of small networks, namely the Micro-Grids, reproducing in themselves the structure of the main production and distribution of the electrical energy system. In order to gain an adequate reliability level of the microgrids the individuation and the management of the faults with the goal of maintaining the micro-grid operation (fault tolerant operation) is quite important. In the present paper flexible power converters and a companion control al…
Decentralized Synchronization for Zigbee wireless sensor networks in Multi-Hop Topology
2010
Abstract The most effective solution for energy saving in low-rate wireless sensor networks is maintaining each node in a doze state as long as possible. In order to guarantee network connectivity, the intervals at which the network sensors are turned on and off have to be coordinated. We analyze the Zigbee MAC performance in sensor networks deployed in multi-hop topologies. For this networks, critical inefficiencies can arise due to transmissions performed by hidden nodes. We evaluate the impact of different synchronization schemes on the network performance, both in terms of network capacity and in terms of energy consumption. We show how the synchronization function can be opportunistica…
Independent energetic grids for a smart island: Model and design of a microgrid for a small Italian island
2016
Unlike many Italian peninsular areas, which are increasingly turning to a diverse supply of renewable resources to generate electricity, Italian not-interconnected small islands continue to rely on oil for their electricity and other energy needs (e.g. transports). Small-scale electricity systems, that are not connected to a larger electricity grid, are usually more expensive. The present paper proposes the functional design of an innovative Smart Grid which allows changing an Italian small not-interconnected island, Pantelleria, into a smart island, towards a more sustainable energy model. In detail, a techno-economic feasibility study is performed in order to design a Smart Grid at Pantel…
A unified radio control architecture for prototyping adaptive wireless protocols
2016
Experimental optimization of wireless protocols and validation of novel solutions is often problematic, due to limited configuration space present in commercial wireless interfaces as well as complexity of monolithic driver implementation on SDR-based experimentation platforms. To overcome these limitations a novel software architecture is proposed, called WiSHFUL, devised to allow: i) maximal exploitation of radio functionalities available in current radio chips, and ii) clean separation between the logic for optimizing the radio protocols (i.e. radio control) and the definition of these protocols.
Redes de apoyo al emprendimiento femenino en territorios rurales
2020
Las condiciones del mercado de trabajo en las áreas rurales han convertido el autoempleo en una de las opciones recurrentes entre las mujeres que tratan de iniciar una actividad o consolidar su económica. Mediante técnicas cualitativas y a partir de un caso de estudio en un área LEADER española (Sierra del Segura, Albacete), este trabajo investiga las redes locales de apoyo al autoempleo femenino en zonas rurales, así como el impacto de la crisis económica sobre dicho sistema de apoyos. Los resultados más destacados señalan la importancia del asociacionismo empresarial femenino (redes formales) y los liderazgos locales (redes informales) como apoyos-fuerza al emprendimiento femenino rural. …
Entrepreneurs’ interpersonal communication competence in networking
2020
Modern international business calls for competencies that enable entrepreneurs to be creative, innovative, effective and capable of networking. Competencies in forming and developing networks are particularly valuable for organizations and companies in countries with small economies, such as Finland, that are dependent on export and profitable international business. The aim of this research is to build understanding of what kind of interpersonal communication competence (ICC) entrepreneurs need in networking.
 Since the classic work of Granovetter (1982) and others (see e.g. Håkansson, 1982; Håkansson & Snehota, 2000), network theory and network analysis have become popular when t…
Modelling the metabolic shift of polyphosphate-accumulating organisms
2014
Enhanced biological phosphorus removal (EBPR) is one of the most important methods of phosphorus removal in municipal wastewater treatment plants, having been described by different modelling approaches. In this process, the PAOs (polyphosphate accumulating organisms) and GAOs (glycogen accumulating organisms) compete for volatile fatty acids uptake under anaerobic conditions. Recent studies have revealed that the metabolic pathways used by PAOs in order to obtain the energy and the reducing power needed for polyhydroxyalkanoates synthesis could change depending on the amount of polyphosphate stored in the cells. The model presented in this paper extends beyond previously developed metaboli…
Network pharmacology of cancer: From understanding of complex interactomes to the design of multi-target specific therapeutics from nature
2015
Despite massive investments in drug research and development, the significant decline in the number of new drugs approved or translated to clinical use raises the question, whether single targeted drug discovery is the right approach. To combat complex systemic diseases that harbour robust biological networks such as cancer, single target intervention is proved to be ineffective. In such cases, network pharmacology approaches are highly useful, because they differ from conventional drug discovery by addressing the ability of drugs to target numerous proteins or networks involved in a disease. Pleiotropic natural products are one of the promising strategies due to their multi-targeting and d…