Search results for "Module"

A presentation and a representation of the Held group

1996

In this note we give a brief description of a new presentation of the Held group, which is deduced only from the original work of D. Held in 1969, who shows that a finite simple group, having the same centralizer of a 2-central involution as in the Mathieu group M24, is M24, L5(2) or a group of order 4.030.387.200. The first complete uniqueness proof for the latter case was given by L. Soicher in 1991. The generators and relations occurring here are easy to verify by a simple Todd–Coxeter algorithm. It is an easy task to get a new uniqueness and existence proof of the Held group from this result. Also basic facts like the Schur Multiplier or the automorphism group of the Held group follow f…

Faithful representations of left C*-modules

2010

The existence of a faithful modular representation of a left module $$ \mathfrak{X} $$ over a C*-algebra $$ \mathfrak{A}_\# $$ possessing sufficiently many traces is proved.

Invertibility in tensor products of Q-algebras

2002

Star representations of E(2)

1990

We give a complete and explicit realization of the unitary irreducible representations of the universal covering group G of E(2), the Euclidean group in two dimensions, by deformation of the algebra of functions on the dual g* of the Lie algebra of G. We define an adapted Fourier transform for G which gives a natural description of the harmonic analysis of G.

A procedure to calculate the I–V characteristics of thin-film photovoltaic modules using an explicit rational form

2015

Abstract Accurate models of the electrical behaviour of photovoltaic modules are effective tools for system design. One or two diode equivalent circuits have been widely used even though some mathematical difficulties were found dealing with implicit equations. In this paper, a new model based on a simple rational function, which does not contain any implicit exponential form, is presented. The model was conceived in order to be used with thin-film photovoltaic modules, whose current–voltage curves are characterised by very smooth shapes. The parameters of the model are evaluated by means of the derivatives of the issued characteristics in the short circuit and open circuit points at standa…

An accurate one-diode model suited to represent the current-voltage characteristics of crystalline and thin-film photovoltaic modules

2020

Abstract In this paper a new one-diode model, conceived in order to be used to represent the current-voltage curves of both crystalline and thin-film photovoltaic modules, is presented. The model parameters are calculated from the information contained in the datasheets issued by manufactures by means of simple iterative procedures that do not require the assumption of simplifying hypotheses. Some innovative relations describing the dependence of the parameters from the solar irradiance and cell temperature are adopted in order to permit the model to reliably simulate the electrical behaviour of photovoltaic devices operating in real conditions. The ability of the model to calculate the cur…

A Hardware and Secure Pseudorandom Generator for Constrained Devices

2018

Hardware security for an Internet of Things or cyber physical system drives the need for ubiquitous cryptography to different sensing infrastructures in these fields. In particular, generating strong cryptographic keys on such resource-constrained device depends on a lightweight and cryptographically secure random number generator. In this research work, we have introduced a new hardware chaos-based pseudorandom number generator, which is mainly based on the deletion of an Hamilton cycle within the $N$ -cube (or on the vectorial negation), plus one single permutation. We have rigorously proven the chaotic behavior and cryptographically secure property of the whole proposal: the mid-term eff…

Experimental test on a Contactless Power Transfer system

2014

Contactless Power Transfer (CPT) is an ever-growing technology in automotive market, due to the significant improvement brought by it to battery charging operation in terms of safety and comfort. CPT is based on inductive coupling between two coils, so that power cords can be avoided for vehicles battery charging and an important contribution towards a smarter mobility can arise. In this paper, a CPT prototype for E-bike is proposed. Magnetic design and power electronics system are described. Experimental results deriving from laboratory tests are presented and power efficiency of the system is addressed.

Dynamic Community Detection for Brain Functional Networks during Music Listening with Block Component Analysis

2023

Publisher Copyright: Author The human brain can be described as a complex network of functional connections between distinct regions, referred to as the brain functional network. Recent studies show that the functional network is a dynamic process and its community structure evolves with time during continuous task performance. Consequently, it is important for the understanding of the human brain to develop dynamic community detection techniques for such time-varying functional networks. Here, we propose a temporal clustering framework based on a set of network generative models and surprisingly it can be linked to Block Component Analysis to detect and track the latent community structure…

Towards sustainable Net Zero Energy Buildings: life cycle energy performances and environmental impacts of a prefabricated building module

The impact of prefabrication in the building sector is currently undergoing significant growth. Although prefabricated buildings cannot in any situation replace conventional buildings, they have some characteristics, such as reduced construction time, higher safety during construction if compared to traditional buildings and modularity, that make them competitive in specific applications, that are undergoing substantial increase importance and market relevance. However, in a context where the transition towards a low-carbon energy system is quickly becoming an important target of scientific efforts and research, prefabricated buildings, as well as any other type of building, will have a key…