Search results for "large scale"
showing 10 items of 51 documents
Forecasting energy output of a solar power plant in curtailment condition based on LSTM using P/GHI coefficient and validation in training process, a…
2022
This study presents how to improve the short-term forecast of photovoltaic plant's output power by applying the Long Short-Term Memory, LSTM, neural networks for industrial-scale solar power plants in Vietnam under possible curtailment operation. Since the actual output power does not correspond to the available power, new techniques (Global Horizontal Irradiance - GHI interval division, P/GHI factor addition (P - Power)) have been designed and applied for processing errors and missing data. The prediction model (LSTM network, structure of hidden layers, number of nodes) has been developed by the authors in a previous work. In this new version of the model, the training technique is improve…
Contribution to the analysis of signals obtained by dynamic photon emission for the purpose of studying very large scale integration circuits
2014
Scaling progresses has the benefit of making chips always more powerful. On the other hand, when there is a failure, the analysis of such advanced devices has became more sensitive. The defect localization step of this process is the critical one. Indeed, the aim is to find transistors which dimensions range in several nanometers on a device which surface is several square centimeters.Optical techniques like dynamical photon emission, also named Time Resolved Imaging (TRI), have proved to fit in such context. The later is based on the acquisition and exploitation of photons emitted by a switching CMOS structure. Due to its physical bacground, this tool has a limited invasive effect and can …
Direct observation of coherent magnons with suboptical wavelengths in a single crystalline ferrimagnetic insulator
2019
In the field of magnetism, spin waves are a subject of great interest for fundamental and application-oriented research. Time-resolved scanning transmission x-ray microscopy, a technique that allows for direct spin-wave imaging below the optical resolution limit, is usually limited to thin layers deposited on x-ray transparent membranes. Here, the authors report on a preparation routine that makes single-crystalline materials accessible to this powerful technique. The latter is subsequently implemented on the ferrimagnetic insulator yttrium iron garnet, where spin waves down to 100-nm wavelength are observed.
Nanoscale X-Ray Imaging of Spin Dynamics in Yttrium Iron Garnet
2019
Time-resolved scanning transmission x-ray microscopy (TR-STXM) has been used for the direct imaging of spin wave dynamics in thin film yttrium iron garnet (YIG) with spatial resolution in the sub 100 nm range. Application of this x-ray transmission technique to single crystalline garnet films was achieved by extracting a lamella (13x5x0.185 $\mathrm{\mu m^3}$) of liquid phase epitaxy grown YIG thin film out of a gadolinium gallium garnet substrate. Spin waves in the sample were measured along the Damon-Eshbach and backward volume directions of propagation at gigahertz frequencies and with wavelengths in a range between 100~nm and 10~$\mathrm{\mu}$m. The results were compared to theoretical …
Cosmologie des théories de gravite modifiées
2017
The study of physical cosmology has reached an exciting era. For the first time in human history, a quantitative model for the formation and the evolution of the Universe exists, which explains a wide range of phenomena and has been tested with incredible accuracy during the last century. Moreover, weare approaching a time when a bounty of high quality cosmological data will be available,allowing us to use cosmology as a tool to test fundamental physics.In particular, as the large-scale structures of the Universe are governed by gravity, cosmology can help us to asses the correctness of Albert Einstein’s general relativity. This idea fueledmost of the work described in this manuscript,in wh…
Large-scale distribution of arrival directions of cosmic rays detected above 1018 eV at the Pierre Auger Observatory
2012
A thorough search for large-scale anisotropies in the distribution of arrival directions of cosmic rays detected above 1018 eV at the Pierre Auger Observatory is presented. This search is performed as a function of both declination and right ascension in several energy ranges above 1018 eV, and reported in terms of dipolar and quadrupolar coefficients. Within the systematic uncertainties, no significant deviation from isotropy is revealed. Assuming that any cosmic-ray anisotropy is dominated by dipole and quadrupole moments in this energy range, upper limits on their amplitudes are derived. These upper limits allow us to test the origin of cosmic rays above 1018 eV from stationary Galactic …
Galaxy clustering: a point process
2016
El 'clustering' de galàxies és l'agregació de galàxies en l'universe produida per la força de la gravetat. Les galàxies tendeixen a formar estructures de major tamany tal com 'clusters' o filaments que formen la xarxa còsmica ('Cosmic Web'). Aquesta Estructura a Gran Escala de l'Univers es pot entendre com el resultat de la distribució de galàxies, un procés en el qual totes les galàxies estan subjectes a forces comuns i comparteixen propietats universals. L'anàlisis d'aquesta distribució es pot realitzar amb técniques de processos puntuals, l'estudi de configuracions de punts sobre un marc. En aquesta tesi fem servir aquesta branca de la estadística en tres approximacions diferents: els es…
Il difficoltoso percorso del Piano paesaggistico siciliano
2020
Nel 1999, la Sicilia, con anticipo rispetto alle regioni ritenute all’avanguardia nella gestione del proprio territorio e del proprio paesaggio, aveva individuato nello strumento del Piano Paesaggistico il mezzo attraverso cui perseguire la protezione e la salvaguardia del proprio patrimonio culturale e naturale. Alla caparbia e avveduta intuizione però sono succeduti anni di lungaggini amministrative, di numerosi silenzi e scellerati colpi di spugna. Dopo ventun anni, sono finalmente stati adottati e approvati i piani paesistici di gran parte dei 17 ambiti identificati dal documento del 1999. E qual è la reazione di quei territori che frattanto, in un ventennio, hanno subito non pochi camb…
Large scale modelling of photo-excitation processes in materials with application in organic photovoltaics
2019
La energía fotovoltaica a partir de materiales orgánicos representa una opción muy atractiva, en términos de costo y flexibilidad, para generar electricidad. Sin embargo, las bajas eficiencias alcanzadas hasta ahora limitan la producción de dispositivos fotovoltaicos a escala comercial. En el intento de superar las bajas eficiencias hoy en día se dedican considerables esfuerzos en la investigación y el diseño de materiales orgánicos así como de arquitecturas de dispositivos más eficientes. En particular esta tesis doctoral presenta un trabajo de carácter fundamental sobre los procesos de fotoexcitación en dispositivos optoelectrónicos orgánicos, donde se usan química teórica y modelización …
Customer satisfaction within a large scale retail trading group: research design and control
2010
Even in contexts where Customer Management techniques are not very advanced, the need for relations with customers is as strong as to suggest expensive ad hoc researches able to simultaneously measure the satisfaction levels, to detect the eventual inadequacy of selling actions, to investigate the relations of customers with competitors. This is why the Grande Migliore Group in Palermo commissioned a research from the University of Palermo. The research was made in year 2008 at 10 Grande Migliore shops in Palermo and in other Western Sicily towns. The multipurpose nature of the research and the features of the customers population suggested the adoption of an ad hoc research design, the fea…