An optimal approach for load-frequency control of islanded microgrids based on nonlinear model

Due to the increased environmental and economic challenges, in recent years, renewable based distribution generation has been developed. More penetrations from the side of consumers caused a new concept called microgrids which are able to stand with or without connection to the bulk power system. Control of microgrids in islanded mode is very crucial for decreasing the amplitude of frequency deviations as well as damping speed. This chapter aims to propose an optimal combination of FOPD and fuzzy pre-compensated FOPI approach for load-frequency control of microgrids in islanded mode. The optimization parameter of the control scheme is designed by the differential evolution (DE) algorithm which has been improved by a fuzzy approach. In the optimization, control effort is considered as a constraint. Due to the robustness and flexibility of the proposed method, the simulation results have been improved substantially. Robust performance of the proposed control method is examined through sensitivity analysis.fi=vertaisarvioitu|en=peerReviewed

End-tidal carbon dioxide (ETCO2) and ventricular fibrillation amplitude spectral area (AMSA) for shock outcome prediction in out-of-hospital cardiac arrest. Are they two sides of the same coin?

Aim: Ventricular fibrillation amplitude spectral area (AMSA) and end-tidal carbon dioxide (ETCO2) are predictors of shock success, understood as restoration of an organized rhythm, and return of spontaneous circulation (ROSC). However, little is known about their combined use. We aimed to assess the prediction accuracy when combined, and to clarify if they are correlated in out of hospital cardiac arrest' victims. Materials and Methods: Records acquired by external defibrillators in out-of-hospital cardiac arrest patients of the Lombardia Cardiac Arrest registry were processed. The 1-min pre-shock ETCO2 median value (METCO2) was computed from the capnogram and AMSA (2\u201348 mV.Hz range) computed applying the Fast Fourier Transform to a 2-second pre-shock filtered ECG interval (0.5 1230 Hz). Support Vector Machine (SVM) predictive models based on METCO2, AMSA and their combination were fit; results were given as the area under the curve (AUC) of the receiver operating characteristic (ROC) curves. Results: We considered 112 patients with 391 shocks delivered. METCO2 and AMSA were predictors of shock success [AUC (IQR) of the ROC curve: 0.59 (0.56 120.62); 0.68 (0.65 120.72), respectively] and of ROSC [0.56 (0.53 120.59); 0.74 (0.71 120.78),]. Their combination in a SVM model increased the accuracy for predicting shock success [AUC (IQR) of the ROC curve: 0.71 (0.68 120.75)] and ROSC [0.77 (0.73 120.8)]. AMSA and METCO2 were significantly correlated only in patients who achieved ROSC (rho = 0.33 p = 0.03). Conclusions: AMSA and ETCO2 predict shock success and ROSC after every shock, and their predictive power increases if combined. Notably, they were correlated only in patients who achieved ROSC

Picta fragmenta. La pittura vesuviana: una rilettura

Il pi\uf9 grande archivio della pittura antica: Pompei e la regione vesuviana lo sono ancora, a quasi tre secoli dall\u2019inizio della loro riscoperta. Anche se in questa seconda vita non tutto quello che era stato riportato alla luce ha superato la prova del tempo: molte decorazioni, ancora ben leggibili e ricche di colore al momento del rinvenimento, oggi sono scomparse. Per assicurare anche a chi verr\ue0 dopo di noi la conoscenza di questo eccezionale patrimonio, tanto prezioso quanto fragile, due sono le vie principali da percorrere: la conservazione della materia e il restauro della memoria. Solo attraverso azioni sistematiche di manutenzione i picta fragmenta di Pompei e gli altri vesuviani, cos\uec come quelli di tutti gli altri siti archeologici che hanno restituito tracce delle pareti dipinte del mondo antico, possono resistere all\u2019usura del tempo. Altrettanto importante \ue8 il lavoro di chi cerca di ricondurre i frammenti alla loro situazione originaria, ricomponendo disegni e restituendo colori, con un restauro che pu\uf2 essere reale e materico, ma anche virtuale. Alla base di entrambi sta l\u2019indispensabile miniera di informazioni che generazioni di ricercatori (archeologi, storici dell\u2019arte, archeometri) e di artisti (fotografi, disegnatori, pittori) hanno contribuito a formare. Da questa sinergia di competenze e di indirizzi nasce quell\u2019approccio globale e olistico allo studio della pittura antica che la comunit\ue0 scientifica indica come necessario: per meglio conoscere le pareti antiche in s\ue9, quale espressione di un\u2019arte applicata, e nei loro contesti, e per meglio farle conoscere. Pompei e i siti vesuviani sono, anche in questo, uno straordinario osservatorio-laboratorio: rileggere, con occhi nuovi e nuove domande, quello che delle loro pareti dipinte \ue8 arrivato sino a noi \ue8 l\u2019intento di questo libro. Alla ricerca, a partire dai picta fragmenta, delle picturae antiche: una realt\ue0 al plurale, da indagare con un approccio al plurale