Search results for " mac"
showing 10 items of 3066 documents
A multi-input, single-inductor power system for multisource energy harvesting
2013
Today, energy harvesting is drawing a great deal of attention due to modern trends in energy saving and sustainable development purposes. Among renewable energy sources fuel cells and photovoltaic arrays are the most promising for a wide variety of applications, ranging from few mWatts of wireless sensor networks to kWatts for household appliances. Coupling several harvesters and renewable sources is the winning strategy to ensure a proper supply overcoming the uncertainty and limited availability of common harvesters and renewable sources. Multisource energy harvesting is actually an open research topic involving several pressing and often conflicting requirements. System cost, complexity,…
Speed detection of battery-free nodes based on RF Wireless Power Transfer
2020
In the Internet of Things (IoT) era, Wireless Sensor Networks (WSNs) are rapidly increasing in terms of relevance and pervasiveness thanks to their notable real-time monitoring performance across several fields, including industrial, domestic, military, biomedical, commercial, environmental, and other sectors. A highly attractive implementation of WSNs is asset tracking with accurate data regarding the location and transportation conditions of goods, equipment, and the like. One highly promising application of WSNs along these lines is the remote speed monitoring of goods, ideally with battery-free sensor nodes that do not require any maintenance. This, however, represents a major challenge…
Hybrid Energy Storage Modeling And Innovative Solutions For Energy Storage Management Systems
2022
La presente tesi riguarda la modellazione di diverse fonti di accumulo di energia elettrica, in particolare batterie e supercondensatori (SC), e di nuove configurazioni di metodi di gestione di sistemi di accumulo di energia ibridi . Il crescente bisogno di domanda di energia e il desiderio di raggiungere uno sviluppo sostenibile, si riflettono nell'uso di Generatori Distribuiti (DG) basati sulle Fonti energetiche Rinnovabili (FER). L'uso di un controllo di supervisione intelligente e il raggruppamento locale della domanda e della generazione possono portare a notevoli miglioramenti nell'efficienza, affidabilità e resilienza del sistema elettrico. Il problema principale della DG basata sull…
Accessibility of Cultural Heritage in the Virtual Environment of Latvia Memory Institutions
2014
The aim of research is to evaluate the level of e-service provision in digital collections created by memory institutions (libraries and archives) of Latvia. The problem under study is as follows: digital collections have insufficient usability due to lack of appropriate e-services. The empirical basis for research is e-services of digital collections created by national and regional level libraries, as well as the National Archives of Latvia. The evaluation of e-services is based on 14 indicators within 7 categories: visibility, search, reference, personalization, user participation, instructions, and document delivery. The analysis reveals that the level of eservice development is quite l…
Voltage source inverters: An easy approach for fast fault detection
2013
Fault-tolerant converters have been widely investigated for years and nowadays an extensive technical literature on this field exists. This paper presents a novel fault detection algorithm based on a simple geometrical approach. In the algorithm analysis both the case of faults in single device and the loss of an entire inverter leg have been considered. The proposed methodology is characterized by simplicity, low computational and implementation effort with a consequent fast execution and easy control integration. The suggested algorithm is verified by means of experimental tests and reveals a valid and suitable alternative to the existing state of the art in the field of inverter fault de…
Reliability Analysis of Three Homogeneous Fault-tolerant Inverter Topologies
2016
Abstract—In this article, non-redundant fault-tolerant inverter topologies are addressed. A novel fault-tolerant control strategy which enhances performances during post-fault operation is proposed. Benefits from the proposed strategy over conventional fault-tolerant topologies are investigated in terms of system reliability. Cost, post-fault performances, and system reliability of the proposed solution are compared with both a conventional triac-based fault-tolerant inverter and a T-type inverter. The reliability analysis of each selected configuration is carried out by means of Markov chains. The analysis is validated through a comparison of reliability and sensitivity curves. As shown by…
Patriarchal reaction against advances in sexist violence
2019
La violencia que se ejerce contra las mujeres es una violación de los derechos humanos muy extendida, y, en gran parte, impune en todo el mundo. Cuando parecía que existía un consenso en el abordaje de la violencia machista, actualmente nos enfrentamos a una amenaza de retroceso, que intenta poner en cuestión, incluso, el concepto acordado por Naciones Unidas (1979), OMS (2002), el Convenio de Estambul (2011) y la Ley Orgánica 1/2004, de 28 de diciembre, de Medidas de Protección Integral contra la violencia de género en el caso del Estado español. Este artículo es una reflexión, basada en la idea de que las sociedades democráticas tenemos la obligación de blindar la defensa de los derechos …
Characterisation of Fibre Glass Panels for Naval Use
2004
This work examines the characteristic of fiber glass composite panels constructed by Cantieri Arturo Stabile in Trapani (Italy): composite materials are very used in the naval applications, where high stiffness and resistance are required with reduced weight. Experimental tests are executed following ASTM or UNI EN rules, in particular the shear test is executed using a rig constructed to the purpose, designed following the rule ASTM D 4255-83. Besides the tests were simulated by analytical methods, by means of Cadec software and numerically by FEM software as Altair Hyperworks and Ansys, to evidence the error range of the experimental test and to obtain the configuration that can give suit…
Impact of pericardial effusion on cardiac mechanics in patients with dilated cardiomyopathy
2013
Dilated cardiomyopathy (CDM) is a degenerative disease of the myocardium accompanied by left ventricular (LV) remodeling, resulting in an impaired pump performance. Differently, pericardial effusion(PE) is a liquid accumulation in the pericardial cavity, which may inhibit blood filling of heart chambers. Clinical evidence show that PE may improve pump performance in patients with CDM. Therefore, this study aims to assess wall stress and global function of patients with CDM, PE as compared to healthy patient. These findings suggests that CDM has an important implication in the mechanical changes of LV and right ventricle by increasing wall stress and reducing pump function. Conversely, PE de…
Varieties Generated by Certain Models of Reversible Finite Automata
2006
Reversible finite automata with halting states (RFA) were first considered by Ambainis and Freivalds to facilitate the research of Kondacs-Watrous quantum finite automata. In this paper we consider some of the algebraic properties of RFA, namely the varieties these automata generate. Consequently, we obtain a characterization of the boolean closure of the classes of languages recognized by these models.