197,440 research outputs found
PLC for the smart grid: state-of-the-art and challenges
No full textThis paper aims to review systems and applications for power line communications (PLC) in the context of the smart grid. We discuss the main applications and summarise state-of-the-art PLC systems and standards. We report efforts and challenges in channel and noise modelling, as well as in state-of-the-art transmission technology approaches
Design of Orthogonal Filtered Multitone Modulation Systems and Comparison among Efficient Realizations
No full textWe address the efficient realization of a filtered multitone (FMT) modulation system and its orthogonal design. FMT modulation can be viewed as a Discrete Fourier Transform (DFT) modulated filter bank (FB). It generalizes the popular orthogonal frequency division multiplexing (OFDM) scheme by deploying frequency confined subchannel pulses. We compare three realizations that have been described by Cvetković and Vetterli (1998), and Weiss and Stewart (2000), and Tonello (2006). A detailed derivation of them is performed in the time-domain via the exploitation of different FB polyphase decompositions. We then consider the design of an orthogonal FMT system and we exploit the third realization which allows simplifying the orthogonal FB design and obtaining a block diagonal system matrix with independent subblocks. A numerical method is then presented to obtain an orthogonal FB with well frequency confined subchannel pulses for arbitrarily large number of subchannels. Several examples of pulses with minimal length are reported and their performance is evaluated in typical multipath fading channels. Finally, we compare the orthogonal FMT system with a cyclically prefixed OFDM system in the IEEE 802.11 wireless LAN channel. In this scenario, FMT with minimal length pulses and single tap subchannel equalization outperforms the OFDM system in achievable rate
MIMO precoding for filter bank modulation systems based on PSVD
No full textIn this paper we consider the design of a linearly precoded MIMO transceiver based on filter bank (FB) modulation for transmission over broadband frequency selective fading channels. The modulation FB is capable of lowering the channel dispersion at sub-channel level. Nevertheless, the sub-channels experience some level of inter-symbol interference. Therefore, the pre-coder and the equalizer are designed exploiting the polynomial singular value decomposition (PSVD). In particular, we consider two types of FB system. The first system deploys maximal frequency confined pulses and it is referred to as filtered multitone (FMT) modulation, while the second uses maximal time confined pulses with rectangular impulse response, i.e., it corresponds to the conventional orthogonal frequency division multiplexing (OFDM) system. We compare the performance of the considered systems in terms of capacity over typical WLAN channels, showing that PSVD precoding with FMT can outperform the performance of precoded OFDM in the two-bytwo antenna case especially for moderate to low SNRs
Platelet and Brain Fatty Acids: a model for the classification of the animal world? Part I
No full textRecently Cocchi-Tonello have investigated the platelet fatty acid profile in normal and depressive subjects.
The data allowed us to create a particular Artificial Neural Net¬work, the so-called Self Organizing Map (SOM).
The SOM distributes all the subjects investigated over a plane, also according to the degree of saturation/unsaturation of the fatty acids identified as markers of the depressive pathology (Palmitic Acid, Linoleic Acid, Arachidonic Acid).
In this way it is possible to distribute all animals and humans over the map according to the percentage of the fatty acids (Pal¬mitic Acid, Linoleic Acid, Arachidonic Acid)characteristic of each of the animal species investigated.
Because of the specific characteristics of the SOM and the af¬finity of the platelet with the neuron, we considered that the SOM could also be used to classify the brains of different ani¬mal species. Because of the low level of Linoleic Acid in the brain, all the brains were classified in the same position on the map, very close to the area of depressive subjects.
Is the brain genetically organized for the risk of depression? In this sense, is the brain, influenced by the modulation of the fatty acids or by the gene expression of the fatty acids? We do not yet know the final answers to these questions, but it is significant that the fatty acids which make the difference be¬tween the normal condition and the depressive condition shape the brain in the way we found. In any case, we know that Major Depression is characterized by a high level of Arachidonic Acid, both in platelets and in the brain
An Emerging Concatenated Multitone Air-Interface for High Speed Access and Home Wireless Networks
No full textDoes increasing compulsory education decrease or displace adolescent crime? New evidence from administrative and victimization data
No full textThis article estimates the contemporaneous effect of education on adolescent crime by exploiting the implementation a reform that increases the school leaving age in Italy by 1 year. We find that the Reform increases the enrollment rate of all ages but decreases the offending rate of 14-year-olds only, who are the age group explicitly targeted by the Reform. The effect mainly comes from natives males, while females and immigrants are not affected. The Reform does not induce crime displacement in times of the year or of the day when the school is not in session, but it increases violent crimes at school. By using measures of enrollment and crime, as well as data at the aggregate and individual level, this article shows that compulsory education reforms have a crime-reducing effect induced by incapacitation but may also lead to an increase of crimes in school facilities plausibly due to a higher concentration of students
Alternanza di Governo nell’Unione Europea 2008-2015
No full textLo studio del populismo sta vivendo un periodo di grande fulgore, testimoniato da una copiosa produzione scientifica e da una costante attenzione mediatica. Partiti e movimenti populisti hanno ottenuto significativi successi elettorali in diversi paesi europei e, sebbene in appena tre casi una forza politica di questo tipo si trovi al governo (Ano 2011 in Repubblica Ceca, Syriza in Grecia e Law and Justice in Polonia), la loro affermazione elettorale ha tolto voti sia ai partiti di governo che alle opposizioni.European politics seems to be in a period of dramatic change. Exasperated by the Great Recession, voters are disillusioned and the political class suffers from a loss of trust, with mainstream political parties losing popularity and party membership. Europe's political crisis of representation also shows itself in the rise of new forms of ‘anti-system politics’, notably the insurgency of new forms of populism and anti-establishment politics. Mainstream political parties are losing votes and the voter turnout is decreasing in several countries.
Whilst covering the characteristics of ‘new parties’ and populist parties in Europe, this research investigates the government turnovers in the 28 EU countries, showing that mainstream political parties have been able to resist in power in several cases, through the help of the voting systems’ features and the establishment of grand coalitions
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